THE

VOYAGE OF H.M.S. CHALLENGER.

ZOOLOGY.-VOL. III.

( Provisional Title )

REPORT

Qbc

ON THE

SCIENTIFIC RESULTS

OF THE

VOYAGE OF H.M.S. CHALLENGER

DURING THE YEARS i87 3-7 6

UNDER THE COMMAND OF

Captain GEORGE S. NARES, R.N., F.R.S.

AND

Captain FRANK TOURLE THOMSON, R.N.

PREPARED UNDER THE SUPERINTENDENCE OF

Sir C. WYVILLE THOMSON, Knt, F.R.S., &c.

REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF EDINBURGH
DIRECTOR OF THE CIVILIAN SCIENTIFIC STAFF ON BOARD

ZOOLOGY— VOL. III.

IPubUsIjeD bp <0rDer of l^er iBajestp's (Sotoernment

PRINTED FOR HER MAJESTY'S STATIONERY OFFICE

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1881

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CONTENTS.

j^ L — Report on the Echinoidea dredged by H.M.S. Challenger, during the years

1873-1876.

By Alexander Agassiz.

{Received Septemher 1, 1880.)

-/- II. — Report on the Pycnogonida dredged by H.M.S. Challenger, during the years

1873-1876.

By Dr P. P. C. Hoek, A.ssistant at the Zootomical Laboratory of Leiden LTniversity.

{Received Fehruanj 20, 1881.)

190U

N 0 T I C E.

I FIND it difficult to express my obligation to my friend, Mr Alexander Agassiz,
for the valuable assistance which he has given me in carrying out this under-
taking.

Shortly after the return of the Challenger Mr Agassiz came to Scotland,
and we went over the enormous collection together, when his remarkable
familiarity with invertebrate forms was of the greatest possible service in
selecting and separating the different groups, and preparing them for the
specialists to whom they were finally to be consigned.

Mr Agassiz afterwards undertook the description of the Echinoidea, in
which order his personal acquaintance with all known types, recent and fossil,
gives him an advantage as an authority over all his contemporaries : without
some such special training, it would have been a matter at least of extreme
difficulty to decipher the complex relations of the multitude of singular forms,
intermediate between the faunw of ancient and modern times, which have
been brought to light by the Challenger Expedition.

In all cases in which the question of nomenclature has been left entirely
to myself, I have, after full consideration, adopted the code approved by Mr
Strickland's Committee, and successive Committees of the British Association,
and especially that part which inculcates the reference of the name of every
species to the name of the first post-Linnean describer. My friend and I agree
to differ somewhat on these points, and I here take refuge in my former ex-
planation, that in such cases I can act only as Editor.

Several important contril)utions to the natural history of some of the more
obscure groups of marine articulata, have been for some years known from the

viii THE VOYAGE OF H.M.S. CHALLENGER.

pen of Dr P. P. C. Hoek of the University of Leiden, I have to thank Mr
Darwin for suggesting to me that I should invite Dr Hoek's kind co-operation
in preparing the report upon the Pycnogonida, an aberrant group of Arthropoda
to which we had been fortunate enough to add a large number of novel and
striking species. Dr Hoek's memoir has proved a valuable addition to the
literature of the order, and I am glad to say that Dr Hoek has been induced
to continue his labours by monographing the Cirripedia.

C. Wyville Thomson.

THE

VOYAGE OF H.M.S. CHALLENGEE.

ZOOLOGY.

REPORT on the Echinoidea/ dredged by H.M.S. Challenger during the
Years 1873-1876. Bv Alexander Agassiz.

INTRODUCTION.

In preparing this Eeport on the Challenger Echinoidea, I have purposely limited myself
to such topics as seemed most germane to the object of the Challenger Expedition, viz.,
the careful systematic description of the species collected, and a detailed comparison in
all directions which promised to shed any light on the characteristics of the Echinid fauna
of the depths of the sea.

A careful comparative study of the new species collected by the "Challenger" and by
the " Blake," seems to make a short revision of some of the principal lines of afBnities
of the recent and fossil Echinids desirable; as from our present knowledge of the affinity
of the Echinoidea several groups formerly considered somewhat aberrant can now be
shown to be closely connected. New and most unexpected systematic views have in
many cases been suggested by this comparative study of the striking deep-sea genera.
This comparison is the more interesting, as it brings out more prominently than could
otherwise have been done the genetic succession which undoubtedly exists between
the types still found living at great depths, and other genera characteristic of tlie
Cretaceous and Tertiary periods.

There remains much to be done in the minute anatomy, not only of the new deep-
sea types but of the whole group of Echinoidea. We know as yet practically nothing
of the histology of the principal families ; for this reason I have not attempted a
more detailed examination of the Challenger Echinids, interesting and instructive as
it undoubtedly would have been, since there existed no terms of comparison in the
other groups. To have attempted to carry out such a comparative scheme for the

1 It has beeu foiuid impracticable to incorporate in this Report publications on the Echinoidea which have
appeared during the wnnter of 1879-80 and subsequently.

CS /; (ZOOL. CHALL. EXP. PART IX. 1881.) I 1

2 THE VOYAGE OF H.M.S. CHALLENGER.

anatomy of the Order would have delayed this Eeport far beyond the time allotted to me,
and it was taken for granted that this jaart of the subject would have to be undertaken
de novo for the whole group. The comparisons which have been attempted here are rarely
made from the study of monographs alone; they are based on an extensive acquaintance, not
only with the recent species but also with the fossil. The number of the latter, although
many times greater than that of the recent species, is yet by no means so great^ as to
make an accurate knowledge of all the principal species a difficult task. As it has been
my good fortune to examine for myself all but a few of the deep-sea species collected thus
far, this Eeport has been prepared under the best possible circumstances, with the aid
of the large collections both of recent and fossil species in the Museum of Comparative
Zoology at Cambridge, Mass.

Having described the first important collection of deep-sea Echinids made, that of Count
Pourtales, it has been for me a most gratifying task to work up the report of the magnifi-
cent collection of the Challenger, and to have the opportunity, thanks to the generous
invitation of Sir Wyville Thomson, of going over the whole group of Echinids again with
so much new and important material at my command, which could not fail to develop
many novel and unexpected problems relating to the past and present history of Sea-
•urehins.

Classification.

With regard to the general classification of the Echinoidea, the additional light obtained
from the deep-sea genera regarding the systematic affinities of many fossil forms would
lead us to modify somewhat the systematic arrangements hitherto proposed. I have
already given my reasons for not adopting the artificial classification in vogue ; the
same objections which apply to the system adopted by Wright, apply with equal force to
those of de Loriol and of Zittel, wherever they are based upon characters of such
uncertain value as the presence or absence of teeth, or the presence or absence of actinal
cuts. We, of course, admit the ease of application of these characters as keys for the
identification of fossils, and also the difficulty we find in bringing fossil species within the
limits of the smaller subdivisions adopted among the recent Echinids, from the impossi-
bility of tracing ciiaracters generally imperfectly retained. Several of the sub-families
readily recognised among the recent Echinids are not generally adopted by palasontologists,
and they have, perhaps, in other directions divided the group into smaller subdivisions,
based on structural features which the study of recent tjrpes shows to have but little
value.

I would in the first place regard the Palseechinoidea as one of the sub-orders of
Echinoidea, the others being the Desmosticha, the Clypeastridse, and the Petalosticha.

' According to Zittel the number of fossil species does not exceed 2000.

REPORT ON THE ECHINOIDEA. 3

With regard to the further subdivision of the Palseechiuoidea, the subdivision pro-
posed by Zittel into Cystocidaridse, Bothrioeidaridse, and Perischoechinidse, seems to
represent well our present knowledge of the group. The further subdivision, how-
ever, of the Perischoechinidse into Lepidocentrid^, Melonitidse and Archseocidaridae seems
somewhat doubtful. The Archseocidaridse, at any rate, and the Palgeechinidse
(M'Coy) appear to form most natural subdivisions. The Melonitidse and Lepidocentridse
hardly seem to be sufficiently distinct to be separated into different groups; and the
Palseechiuoidea, as a whole, can hardly be contrasted, after what has been said of the
structure of the test, to all the I'emaining types of Echinoidea, as is proposed by Zittel
and other palaeontologists.

Both in the Desmosticha and in the Petalosticha the difficulties of properly combining
the subdivisions adopted on the one side by palaeontologists, and on the other ]iy those
who have mainly studied recent Echinids, are very great.

The groups recognised by both, and concerning which there seems to be but httlc
question, are the Cidaridse, the Salenidse, and the Echinothuridae. The other subdivisions,
the Arbaciadae, the Diadematidae, the Echinometradae, and the Echinidae, which are in
addition recognised by writers on recent Echinids, are by palaeontologists limited to the
Diadematidae and the Echinidae. This limitation seems scarcely warranted by our know-
ledge of the recent Echinids, while on the other hand our information regarding the
structure of the apical and of the actinal systems of the greater number of the fossil
genera is not accurate enough to enable us to place many of them with any certainty
into the families adopted by those who have limited their studies to recent species. But .
such groups as the Arbaciadae and Echinometradfe, if not of the same systematic value as
the subdivisions Cidaridae, Diadematidae, and Echinidae, are certainly as important as the
Temnopleuridae and Triplechinidae.

As regards the Clypeastroids, the agreement is quite close. We have only to add to
the families recognised by writers on recent species the Galeritidae and the Conocly-
peidae, which are represen.ted by a single recent species only in each group, leaving the
following recognised among the Clypeastroids — the Galeritidae, the Conoclypeidae, the
Euclypeastridae, and the Scutellidae. Among' the Petalosticha the larger subdivisions of
the recent species are the Cassidulidse, still further subdivided into the Echinoneidae
and the Nucleolidae ; and the Spatangidae, with the Ananchytidae, the Spatangina, the
Leskiadae, and the Brissina. The separation of the Holasteridae, as contrasting with
the Spatangidae as a distinct family by some palaeontologists, seems hardly justified from
our present standpoint, and it certainly seems more natural to consider the
Dysasteridae and the Ananchytidae as sub-famiUes of the Spatangidae ; the structure of
the Pourtalesiae and of other recent Ananchytidae seeming to render a separation into
Holasteridae and Spatangidae unadvisable.

4 THE VOYAGE OF H.M.S. CHALLENGEE.

Determination of the Axis of the Echinoidea.

Of the attempts to define from the position of the antero-posterior axis of the Echinids
the relative position of the different zones, by far the most ingenious is that of Loven.^
Adopting the position of the antero-posterior axis of Echinids first defined by Desor,
and subsequently fully elaborated by Cotteau/ he has proposed a most admirable
notation to denote the several ambulacral and interambulacral areas, which simplifies to
a remarkable degree the comparison of the various types, by making it possible to
number conveniently the plates of which these areas are composed, and thus readily to
call attention to any modifications they may undergo. While, however, we shall adopt
generally the nomenclature of Loven, we wish also to be understood as not agreeing with
his conclusions regarding the mode of ascertaining the position of the theoretical axis
which he has adopted.

It will be necessary to give a short resum^ of his method of comparison of the
corresponding ambulacral and interambulacral areas. If we place any recent Spa-
tangoid with the actinal opening upwards and the odd ambulacrum in the line dividing
the petaloid ambulacra symmetrically, and call the left posterior ambulacrum I. ;
the left of the anterior pair II., the odd ambulacrum III., the right anterior IV.,
and the right posterior V., — if we then call the first plates of these ambulacra respec-
tively a, h, in the order of their sequence from right to left, we shall, according
to him, have the following formula to denote the order of identical ambulacral plates ;
the larger plates composed of two primary plates, the sutures of which have disap-
peared, with two ambulacral pores, are La, Il.a, III.6, IV.«, Y.b, while the corre-
sponding plates of the ambulacra belonging to the formula I.b, Il.b, Ill.a, IV.6, V.o,
are smaller and only perforated for a single pore (tentacle).

By going through the whole group of Echinids, exclusive of the Perischoechinidae,
Loven finds that by placing the test in the position indicated, the above formula will
always hold good; that is by placing the test in such a way that the madreporic body is on
the right of the odd ambulacrum, when placed with the actinostome downward. Calling,
again, the interambulacral spaces corresponding to them 1, 2, 3, 4, 5, he finds that the
large and small interambulacral plates in the Echinoidea (exclusive of the Clypeastroids
and Petalosticha) are arranged round the actinal opening according to the formula, la, 2a,
3b, ia, 5a for the small plates, and 16, 26, 3a, 46, 56 for the large plates. Now, Lovdn
gives us to understand that this denotes some special quality in the areas I. to V. and
1 to 5, as he has numbered them. But this it seems to me is not the fact, as we get
an identical formula whether we number each of the five ambulacra and interambulacra
in succession I. to V. or 1 to 5. The result will always be the same, as will easily be seen

' S. Loven, Etudes sur las Echinoidees, Kongl. Svensk. Vetensk. Akad. Handl., xi., No. 7, 1874.
^ G. Cotteau, Note snr la famille des Salenides, Bull. Soc. Gcol. de France, torn, xviii. p. 614, 1861.

REPORT ON THE ECHINOIDEA. 6

on comparing, unitatis mutandis, the following table, which shows the same agreement
pointed out by Lovdn whichever ambulacrum we start with. These formulae are all made
from Lovdn's own figures.

I. Loven's formula —

I La, II. a, III. 6, IV.a, \.h, large plates,
( 1.6, 11.6, III. a, IV. 6, V.a, small plates.

II. Taking the ambulacrum he has called II. as I., we get both for the Spatangoids
and Echinids —

f La, ll.h, Ill.a, IV.6, V.a, large plates,
I Lh, ll.a, III.6, IV.a, V.6, small plates.
If we take III. as I. the formula is —

( 1.6, Il.a, III.6, IV.a, V.a, large plates,
1 La, 11.6, IIT.a, IV.6, V.6, small plates.

If we take IV. as I. —

( La, II.6, Ill.a, IV.o, V.6, large plates,
( 1.6, Il.a, III.6, IV.6, V.a, small plates.

If we take V. as I. —

( 1.6, Il.a, Ill.a, IV.6. V.a, large plates,
I La, II.6, III.6, IV.a, V.6, small plates.

Showing most conclusively that any one of the ambulacra taken as I. will give a corre-
sponding formula for all the Echinids, and that the I. chosen by Loven with reference to
the madreporic body has not the taxonomie value he has suggested, as far as an
antero-posterior axis is concerned, any one of the other ambulacra giving precisely the
same relation. I do not wish by this to deny the importance of the relations between
the ambulacral plates established by Loven. I only wish to show their general character,
and deprive them of the geometric value he has assigned to them. The formulae for the
interambulacral plates are similarly universal.

Taking 1 as adopted by Lovdn —

Lovdn's formula for large plates is 16, 26, 3a, 46, 56,
„ „ small „ la, 2a, 36, 4a, 5a.

Taking 2 as 1 we get —

for large plates, 16, 2a, 36, 46, 56,
„ small „ la, 26, 3a, 4a, 5a.

And so on, the corresponding formulae finding their universal application to all the inter-
ambulacra taken in turn, and that in addition no one has any pre-eminence above any

6 THE VOYAGE OF H.M.S. CHALLENGER.

otliev. It seems to me that Loven's attempt to fix the axis of the Echinoidea by means
of the position of the plates round the actinostome must of necessity fail. It is at the
actiuostome that all the accumulated disturbances during the whole growth of the Sea-
urchin concentrate. It is there that constant resorption and crowding is taking place,
and while acknowledging the infinite skill with which Loven has attacked 'the subject,
many of his conclusions are not of as general application as would at first sight appear.
If we examine in the simplest Echinids (the Cidaridse and Salenidaj) the plates as they
make their appearance around the apical system, we shall find no such general formula as
has been so ingeniously framed for the actinostome. Taking, for instance, the pores at the
actinostome according to Loven's formula in a species of Porocidaris we get the usual
formula La, Il.rt, IIL6, IV.a, V.&, and we have for the interambulacral system a regular
alternation of large and small plates, while at the abactinal system where the plates
appear first we get —

la, ib, 36, 4a, 5a, for the small plates ; and

lb, 2a, 3a, 46, 5h, „ large

In a younger specimen, on the other hand, the interambulacral plates alternate regularly,

and we get —

\b, 2b, 3b, 4b, 5b, for the small plates,
la, 2a, 3a, 4a, 5a, „ large „

Their order and formula depeiiding upon the rate of growth of the smaller interambulacral
plates, which is evidently a rate quite independent in the different interambulacra, and
the formula wiU of course depend upon the particular stage of growth at which the
urchin is examined. In two species of Salenia we find the same difiiculty, Loven's
formula holding good for the actinostome ; as regards the ambulacra, we have the
following formulse difi'erent for the interambulacral plates when we take them as they
appear round the apical system —

16, 26, 3a, 4a, 56, for the smaU plates,
la, 2a, 36, 46, 5a, „ large „

while in another stage of the same species we have the large and small plates regularly
alternating —

la, 2a, 3a, 4a, 5a, for the small plates; and

16, 26, 36, 46, 56, „ large

The same I found to be the case at the apex of Salenia varisjnna. It seems to me that
those who have attempted to define the antero-posterior axis of the Echinids have failed
from their not taking into account the embryological data? These, it is true, are scanty,
yet they are sufiicient to settle the question of the all importance of the madreporic body.

REPOKT ON THE ECHINOIDEA, 7

hoih physiologically and morphologically ; and further, they have failed from not sufB-
ciently taking into account the dorso-central system of Clypeastroids, and in attempting
to pass at once from the Goniocidaridse (the regular Echiuids) to the Spatangoids
(Petalosticha) have left out an important term of comparison.

From embryological data ^ the madreporic body indicates in Echinids, Starfishes and
Ophiurans the line along which the suture of the open spiral of the young Echinoderm
has taken place. It is the only body in the regular Echinoidea which can denote any
axis, and from the mode of development of the interambulacral system, after the
ambulacral, merely indicates that the two ambulacra adjoining it are developed at the
opposite ends of the open spiral once forniing the young Echinoderm ; so that any starting-
point we wish to take, in making out formulae for the arrangement of the plates, ought to
be chosen with reference to the position of the madreporic tubercle, and should be either
the one to the right or to the left of it, that is, either of the ambulacra which Lov^n has
numbered III. and II. They mean something, and have a definite value, which the others
have not ; and the fact that the right anterior interambulacrum frequently contains the
madreporic body in Spatangoids is no proof that the interambulacral area of regular
Echinids which contains it is the right anterior interambulacmm, as has been supposed
by the majority of writers on the Echinoidea.

Nothing in the position of the anus can help us to determine in the Desmosticha which
is the odd interambulacrum except the tendency we see in some genera of the anal
system to approach that interambulacrum ; since while within the genital ring nothing in
its position can guide us to any axis corresponding to that of other sub-orders where
additional structural features leave us no doubt of its position. I have shown in the
Kevision of the Echini that the general trend of the alimentary canal and its windings
are of no assistance in this matter, and that the position of the anus in different
genera of Echinometradse shows that, in the regular Echinoidea at any rate, it cannot be
used to determine any axis ; while, on the contrary, the position of the anus in the
Clypeastroids and Petalosticha, and the frequent specialisation of one of the ambulacra
in the latter, gives us a ready clue to fix the axis of these groups.

The youngest Echinids I have examined, immediately on the resorption of the Pluteus
{Mem. Am. Acad., 1864), show plainly why we should not have the relations between the
different ambulacral and interambulacral plates discovered by Loven limited to a single
one of the zones. The first trace of the ambulacral system in each ambulacrum
consists of five loops becoming subsequently five tentacles, which are absolutely
similar. These large embryonic tentacles are not, as Loven supposes, temporary,
as can be readily seen on examining the figures of the paper referred to above, which
shows the gradual increase in number of the original tentacles, the mode of formation of

' See A. Agassiz, Embryology of Echinoderms, Mein. Am. Acad., 1864 ; A. Agassiz, Embryology of the Starfish,
'1864. .

8 THE VOYAGE OF H.M.S. CHALLENGEE.

additional ones, as new loops immediately below the odd terminal tentacle, being identical
with that in the Starfish. Several recent writers on Echinoderms deny the existence of
this odd terminal tentacle, the homologue of the odd ocular tentacle of the Starfish (see
Embryol. Starfish, pi. viii.). I would refer them to the figures of young Arbacia in the
Revision of the Echini, p. 735, and of young Echinids {Strong ylocentrotus drobachiensis)
in the Mem. Am. Acad., 1864, for figures of this terminal tentacle, and to the Revision of
the Echini, pi. x. 1872, part 3, and to the figures of young Goniocidaris canalicidata in
this memoir (PI. II.). There is nothing to show that the interambulacral zones in the ear-
liest stages at which they can be detected, do not consist at the beginning of several
plates, more or less rudimentary, all appearing at the same time. It seems to me more
natural to suppose that in the Clypeastroids we have the madreporic body in the neutral
position, indicating the mode in which the madreporite passed from an imstable con.dition,
owing to the presence of an apical anal system, to a stable one, due to the withdrawal of
the anal system to one of the interambulacral areas, which then became the principal
guide in fixing the position of an antero-posterior axis until the madreporic body again
had a tendency to encroach upon certain parts of the genital system in the Petalosticha,
when the position of the axis was again defined by the position of the anus and of the
simple ambulacrum.

Far too much weight has been given to the order of appearance of the plates of the am-
bulacral and interambulacral areas in this discussion. The coronal plates, as is well shown
in young Echinids, while divided into ambulacral and interambulacral areas, do not, as far
as we have been able to trace their appearance, develop in such a regular and fixed man-
ner as to enable us to determine the axis of the Echinids from the order of their origin.

COMPAMSON OF THE CORONAL PlaTES OF THE TeST Uf DIFFERENT FAMILIES.

Among the Clypeastroids, it is only in the younger stages that the interambulacral
plates are connected at the actinostome as in Spatangoids. The actinal ambulacral plates
soon increase so fast in width as to drive them apart, and in the older stages of some
genera ^ the second row of ambulacral plates forms a continuous ring round the actino-
stome, while in others ^ the odd posterior interambulacrum still extends connectedly to
the actinostome, as it is in the adult of Echinocyamus and Laganum, and in others form-
ing in part a trivium and a bivium as in Rntula, while in Echinarachnius it is the odd
posterior interambulacrum of which the actinal plates become first disconnected.

Echinoneus comes in at once as a marked exception to Loven's theory, as well as all
the Clypeastroids, where in no stage do we find that the actinal plates have the
characters upon which Loven's theory of an axis is based.

Lov^n has already called attention to the greater affinity existing between the

1 Encope, Clypeaster, Arachnoides. ' Mellita:

EEPORT ON THE ECHINOIDEA. 9

CoUyritidae and the Cassidulidas, and has shown that the separation of the apical system into
a bivium and a trivium, which at first sight appears so important, is not accompanied by
corresponding changes in other structural features of the test. On the contrary, these
groups agree in having comparatively simple ambulacra, without great differences in the
size of the plates of the interambulacra, and are thus more closely related still to the
Echinoneidse of the secondary period, of which they appear to be at the present day the
representatives ; and it is by the changes taking place in the odd posterior inter-
amljulacrum that this group approaches at last more closely the recent Spatangoids.

Loven is disposed to consider the second actinal plate of the right posterior inter-
ambulacral plates as made up of the plates 2:2. I am more inclined to consider the
first and second plate as the breaking up of the first actinal plate into two parts,
as a similar splitting up of the actinal plates frequently occurs in the very elongate
plates of the actinal plastron of other Spatangoids. From the very fact that in such
closely allied genera as Hemiaster and Faorina the second plate is, according to Loven
himself, made up in the one case of 2:2, and in the other 2:3, I am the more inclined to
look upon this as a mechanical result due to the irregular termination of the median
interambulacral line of the posterior pair of interambulacra compared to the anterior
pair, and thus far nothing has been traced in the growth of the young Spatangoids to
sustain the view taken by Loven. It seems to me, on the conti'ary, that it is in the
modifications of the odd posterior interambulacral area that we must look for the passage
between the two groups of Spatangoids which Loven has followed. These can still be
traced, but very imperfectly, in the other lateral interambulacra which are not as deeply
afiected by the change of form as the odd posterior interambulacral area. I am rather
inclined to look upon this heteronomy of the right posterior interambulacrum, which
Lovdn has noticed, as the last trace of the structural affinity of the Clypeastroids
to the Spatangoids, the more so from the existence of such a genus as Palceostoma, in
which we find in all the paired ambulacra two single actinal plates in succession, the last
trace of the zigzag arrangement of the actinal plates of the paired interambulacral spaces.
If, on the other hand, with this explanation of the modifications of the paired lateral
interambulacra, we trace the changes which the odd interambulacrum undergoes, we can
trace these directly either to the more or less central ^losition of the actinostome or to
the elongation of the test which greatly modifies the composition of the plates of the
actinal plastron, and this, it seems to me, is a more natural explanation of the hete-
ronomy existing in the Spatangoids than the ingenious homologies of the successive
soldering of the plates 2 :2 or 2 :3 advanced by Lov^n.

Older writers on the Echinoidea have already insisted on the similarity of the plates
composing the different ambulacral and interambulacral areas in the regular Echinids,
and their difference in the so-called irregular Echinids. This division, which at first sight
seems so fundamental, is most artificial ; and when we carefully analyse such groups as the

(ZOOL. CHALL. EXP. PART IX. — 1881.) I 2

10 THE VOYAGE OF H.M.S. CHALLENGER.

Discoideae and the Clypeastroids, and compare them to the true Spatangoids, it seems
impossible any longer to lay stress upon the characters which have mainly led palae-
ontologists to adopt these two great primary divisions. As has abeady been pointed
out by Lov(^n, the variations introduced are greatest on the actinal surface, and greatest
in the posterior region of the test. In the Echinoidea the first trace of such a want
of symmetry on the actinal side is found in the Echinometradae, while on the abactinal
surface the position of the anal plate in certain genera of Echinids, especially of the anal
plate in the Salenidae, indicates very early the tendency to an asymmetrical development
which culminates in the Sj)atangoids of the present day. The next stage in this
asymmetrical development is due to the exclusion of the anal system from the
apical system, and the corresponding marked distinction at once existing among the
Discoideae in the arrangement of the plates of the odd posterior interambulacral area, and
the compact apical system thus formed, which becomes the basis of the subsequent
modifications it undergoes on the one side in the Clypeastroids, from the soldering of the
plates by the spreading of the madreporic body, and the exclusion of the genital openings
from the apical system, and their appearance in the apical part of the interambulacral
region ; and on the other either into the compact apical system of the recent Spatan-
goids or the disjunct apical system of the CoUyritidae.

In the Clypeastroids the asymmetry of the plates is almost entirely limited to the
posterior interambulacral area, and the further extensive development of the coronal
plates of the test which is limited to the whole of the actinal surface, and not to a single
area as in the Spatangoids proper.

Passing from the Discoideae to the Cassidulidae we find there a further modification of
the actinal surface from that of the former group extending to the actinostomic plates
which still exists at the present time ; and the first trace also of a more distinct petaloid
system than we find among the CoUyritidae. The asymmetry of this group is limited to
the actinal surface, and to the odd interambulacral area. If we further examine the
older Spatangoids we find that in all the more globular genera, such as Hcmiaster, there
is a marked uniformity in the size and number of the coronal plates ; though by no means
so great as that in the CoUyritidae or such genera as Galerites and the like, of which the
deep-sea genera belonging to the Pourtalesiae, such as Cystechinus and similar forms,
may be considered as the representatives; and thus we little by little pass from genera in
which the actinal plastron differs only slightly from the other interambulacra, Cassidulus,
Holaster, Pourtcdesia, Genicopatagus, and Hemiaster to the genera with a more marked
actinal plastron, such as Palceostoma, Agassizia, and Spatangus, and finally to Meoma,
Brissojms, Ecliinocardium, Brissus, &c. It by no means follows, however, that the
specialisation of the ambulacral petals has kept pace with this elongation of the actinal
plastron, as can readily be noticed on comparing such widely-differing genera as Echino-
cardium, Spatangus and Schizaster, which are all characterised by this highly-developed

EEPORT ON THE ECHINOIDEA. 11

actinal plastron of which, perhaps, the most embryonic type is that of the Ananchytidaj,
in which the plates comprising it are more or less hexagonal or pointed, extending beyond
the median interambulacral line.

Very important changes also take place in the actinostomic plate of the odd interam-
bulacral area, which becomes, as is well known, the lip terminating the more or less keeled
actinal plastron, which thus becomes a kind of plough to shovel into the actinostome the
sand or mud in which such forms live. It is upon this plastron also that we find developed
the flat paddle-shaped spines so characteristic of the Spatangoids of the present day.
This lip is but little prominent in the older Spatangoids, it has no prominence in the
Collyritidse; in fact, we might call that form of actinostome the palseostome. It is still
represented at the present day in PalcBOStoma, and the young of all Spatangoids have such
an actinostome of a more or less pentagonal form. In the Clypeastridse, the Galeritidse,
and the Cassidulidfe we have modifications of the actinostome which subserve more or less
the same purpose as the strongly labiate actinostome of the majority of recent Spatan-
goids ; but in these types the actinostomic plate of the odd interambulacrum is not
specialised, and we can trace its growth very satisfactorily from the CoHyritidse to the
Hemiasteridse, the Spatangidae, and the Schizasteridse of the present day, while we find
in the Pourtalesise and in Palceostoma the persistence of the ancient actinostome, com-
bined in the latter with many recent structural features of the Spatangina.

I have already, while speaking of the Pourtalesias, called attention to the mode of
development of the anal snout of that group from the episternum of the Spatangoids
proper.

Anal System.

In the structure of the plates of the anal system we have from embryological data a
clear explanation of the function of the anal plate of the Salenice. This anal plate was,
if we can trust the figures of Schmidt, perhaps abeady developed even in Bothriocidciris,
and may have existed in other Palseechinidae, though it may be difficult in the plates
covering the anal system of that group so easily to recognise the original anal plate as we
can do in many of the recent Triplechinidse. The figures of Bailey, and of Meek and
Worthen, and a specimen of Lepidesthes which I have had occasion to examine, would
seem to indicate a splitting up of the central plate into a great many smaller plates, more
according to the mode in which it takes place in the Arbaciadce. The excentric position
of the anal opening is also clearly shown to be due merely to the development of new plates
along one edge, while where the anal opening is formed symmetrically, we have the anal
system as in the Arbaciadse covered by a few large plates.

The transition of the opening of the anal system to the area within the genital ring,^
and into the odd interambulacral region, as we find it in all Spatangoids, is not, however,

12 THE VOYAGE OF H.M.S. CHALLENGER.

a change of which we can follow the traces in successive geological periods. The
position of this opening is a very variable one, and in the life history of a young
Sea-urchin it passes from its original place near the actinostome to one within the
apical system, plainly showing that during the earliest stages of growth the position
of the external opening of the extremity of the alimentary canal is still undetermined,
and that we must not attempt to find in the geological sequence any explanation of
this transfer any more than the position of the genital opening within or without the
genital plates gives us in the history of the growth of the Clypeastroids any clue to its
causes.

The position of the anal opening among the Spatangoids is in reality, as has been shown
by Loven, not an advance, but the retaining of a structural feature once uniform among
the earliest Echinoderms, and which we find in all the Palseozoic Crinoids, but which may
nevertheless have very gradually been developed again during the geological succession, as
there are indications already in the Palaeechinidae of such an excentric position of the anal
system. And we find, as has been so well shown by Loven, in the older Echinoidea a
marked encroachment of the anal system upon one of the genital plates, which culminates
in some species of Acrosalenia ; and we may consider this as the last trace, perhaps, in the
regular Echinids of the excentric position of the anal system without the apical system,
the last trace of a condition of things which was more universal and which tends gradually
to be constituted as we find it in the Echinids of the present day. While in the groups
in which we find a retrogression, as it were, to the ancient condition of things we find it
accompanied by a renewal of the functions of the genital plates, and at the same time by
the encroachment of the madreporic body upon the other plates, thus often occupying the
whole central part of the apical system, and thus again giving us an explanation of the
many genital plates which may be occupied by parts of the madreporite in the earliest
Palgeechinidse, as we find it in several of the genera figured by Bailey, Worthen, and others.
And we can gradually trace both in the Echinoneidse and in the Cassidulidse the regular
geological succession existing between the genera wath the anal opening close to the apical
system, and those in which at the present day it is found on the actinal surface, and we see
that while the circular or globular species are the more ancient, they are little by little
replaced by species in which the longitudinal axis becomes more marked, the anal system at
the same time gradually passing from the apex towards the ambitus and finally to the actinal
side. This forms a striking contrast to the embryological fact that in young Clypeastroids
the anal opening is at first always on the abactinal side and gradually finds its way to the
actinal surface ; which does not seem to accord well with the view that this tranposition
of the anal opening is of a retrogressive character.

The changes the apical system goes through the moment it has become independent
of the anal system are very important, and are connected also with other modifications in
the plates of the test which radically aff"ect its whole appearance.

REPORT ON THE ECHINOIDEA. 13

The genital plates and the ocular plates, as well as the madreporic body, make the
numerous combinations which have been so well traced by Lovdn, and which culminate
on the one side in such a compact apical system occupied mainly by the madreporic body, as
we have it in the Clypeastroicls, in which the genital openings in some cases no longer retain
a definite position in distinct plates, but may open anywhere in the interambulacral spaces ;
a state of things whose possibility is already foreshadowed in the genera belonging to
types early developed, such as Cidaris and the Echinothuridte. On the other side they
culminate in the great specialisation of the ocular and genital plates and their disturb-
ance by the interambulacral plates, encroaching between them, and little by httle
forming an excessive separation of the ambulacra into a bivium and a trivium, until little
by little it becomes again c^uite compact owing to the more equal development of the
coronal plates near the apical system. As Lov^n has well shown in the older Eehinids
{Cidaris and Salenia), we find all the proof we need of the crinoidial character of the
apical system of the Echinidse ; the calyx being more and more unimportant, though it
always reveals its typical features.

In the Clypeastroids the calyx, though reduced again to its lowest limits, that is,
completely confused, still retains a few traces of its originally crinoid character, and in the
earliest appearance of the Spatangoid calyx we have introduced the embryonic element of
the structure of the calyx, which we find in late types of the present day, and which
recalls to us an arrangement of the plates of the calyx found in the Starfishes only. The
excessive splitting of the arms of an Ophiuran bring the abactinal madreporite to a
position adjoining the actinal opening.

Fascicles.

Fascioles as such are recognised only among the Spatangoids, but it is very probable
that such striking accumulations of miliaiy tubercles as we find on the edge of some of
the Phormosomas must be regarded as the first trace of fascioles, which we would thus be
led to consider as accumulations of miliary tubercles along certain lines, as we find them
in some genera of Spatangoids where their course is not well defined, until at last they
assume the fixity and clear definition which we consider so characteristic of our Spatan-
goids of the present clay. As far as my observations go they do not entirely agree with
those of Lovdn regarding the fixity of their position and the identity of their course in
older and younger specimens. Certainly, from what we have seen in the young of
Hemiaster cavernosus, both the course and position of the peripetalous fasciole is widely
different in the older and younger stages. In the one case the fasciole encloses the anal
system, in the other it is placed outside it. I have also shown the presence of such
rudimentary fascioles in Starfishes,^ so that fascioles are not confined to Eehinids.

Alex. Agassiz, N. Am., Starfish, Cont. Nat. Hist. U. S., vol. v.

14 THE VOYAGE OF H.M.S. CHALLENGER.

We have as yet but few data regarding the development of the fascicles. As far as the
palseontological development is concerned, we find that the earliest Spatangoids, like the
Dysasteridse, have no fascicles. In the Cretaceous period we have at first Spatangoids either
with a peripetalous or with a sub-anal fasciole; then we have Spatangoids with both; and
finally Spatangoids in which the two are connected by a lateral branch, or in which the branch
may form an independent fasciole. We find in Adetes Spatangoids, and in those Spatangoids
which have no peripetalous fasciole, that the passage from the petaloid to the apetaloid
part of the ambulacra is quite gradual, and that in the older genera the plates of the am-
bulacra are of comparatively uniform size from the apex to the actinostome, while in
those genera in which the peripetalous fasciole exists we find a marked contrast between
the infrapetalous plates and the following ones ; and, owing to the crowding of the addi-
tional plates of the petals within this sharply-marked line, we find that the Spatangoids
with peripetalous fascioles also have more markedly petaloid ambulacra. It is also
within the areas of these fascioles that the ambulacral suckers attain a great development
as in Brissojms, in Aempe, in Aceste, in Schizaster, and in the area of the sul>anal
fasciole within which the ambulacral pores often take a very regular arrangement forming
a sort of shield edged by the fascioles. As Loven has akeady suggested, everything we
know of the appearance of the anal fasciole seems to show that the anal, lateral, and
marginal fascioles are only modifications of the sub-anal fasciole and of its branches, and
that the sub-anal fasciole itself may even have originated as a loop of the peripetalous
fasciole, although at present the palseontological evidence renders it somewhat doubtful
whether the sub-anal and peripetalous fascioles have not originated independently. The
internal fasciole I look upon as being an embryonic peripetalous fasciole.^ There is
nothing in the development of the Pluteus to show that the vibratile cords forming such
characteristic fascioles in the larvge of Echinoderms have any relation whatever with the
fascioles of the full-grown Sea-urchin ; yet every writer who has treated the subject of
fascioles invariably goes out of his way to make a comparison between the fascioles and
the vibratile cords of the Pluteus ; as the fascioles are developed on plates which, as a
rule, have not yet appeared during the existence of the \dbratile cords, it seems difiicult
to trace the connection between the two in subsequent stages of growth.

ACANTHOLOGY.

In an exceedingly interesting paper - on the Acanthology of the Desmosticha, Mr
Mackintosh has proposed a classification of the spines of the Desmosticha which, as far
as his sub-series are concerned, agrees weU with the afiinities of the families of the
group as generally adopted. The primary series do not present, it seems to me, the

1 See remarks on Aceste and Aerope.

2 H. W. Mackintosh, On tbe Acanthology of the Desmosticha, Trans. Roy. Irish Acad., vol. xxvi., 1878.

REPORT ON THE ECHINOIDEA. 15

Structural importance assigned to them by Mr Mackintosh, and when we come to include
within his classification the spines of the Spatangoids and Clypeastroids, according to the
structural features he has employed to separate his principal series, we should be com-
pelled to unite into one series groups which have no systematic affinity and are zoologi-
cally widely separated. The mere fact that the spines of the Diadematidje are hollow
does not seem a sufficient reason for contrasting them to the spines of all the other
Desmosticha. I should be more inclined to consider the spines of the Diadematidse
(adopting the nomenclature of Mackintosh) as monocyclic Acanthosphenota, with a more
or less hollow interior. An excellent example of the type showing affinities to the
Diadematid^ and to the Echinidse is Pseudoholetia ; in one section (PL XXXVIII. fig. 3)
we have the hollow spine as in Diadematidae, in the other (PI. XXXIX. fig. 11) the
central portion of the shaft is completely occupied by reticulations as in the Echinidae.

From the examination of the few young spines of Echinids which have been figured thus
far either by MtiUer^ or by myself,^ there does not seem to be in the early stages very great
differences in the structure of the spines. The young spines are in all cases polygonal,
made up of rectangular meshes placed in regular stories one above the other ; the upper
set of meshes open, while the outer beams send off into the interior smaller rods, the first
rudiments of the second or third row of wedges of the polycyclic spines or merely lateral
offshoots connecting the large calcareous wedges, the original beams forming the
rectangular meshes of the young Sea-urchin. There is no difference in the typical
structure of the spine of the young of Cidaris, Echinus, Strong ylocentrotus, Arhacia,
Echinocyamus, or Schizaster, the genera of which the young spines have thus far been
figured.

The modifications which eventually give to the spines their final characteristics are
all derived from the changes undergone by this single primitive fenestrate type, and
are not features which are found developed eai-ly in the plutean stage, or based upon radi-
cally different types of structure. The very fact that we have among the Echinids the
anomalies to which Mackintosh refers, shows us plainly that the derivation from the
original embryonic type has not gone on during growth equally in all the genera of the
same family, some of the genera retaining a much more embryonic condition than others.
By embryonic, I mean the simple fenestrate structure of the spines such as still exists
among some of the Clypeastroids and Sj^atangoids, in which the reticulation docs not
extend towards the central part of the shafts, or in the simpler monocyclic types of such
genera as Astropyga and the Salmacidse. It is among the Desmosticha, belonging to the
Cidaridse, the Salenidse, the Diadematidse, and the Echinidaj, among the oldest genera,

1 J. Miiller, Ueber die Larven n. Metamorphosen der Opliiuren u. Seeigel, Abband, Berlin Akad., 1848-1855,
Abbandlungen, i., iv., yi., vii.

- A. Agassiz, Embryology of Echinodenns, Mem. An. Acad., 1864 ; The Hoimdogies of Pedicellai:£e, Am.
Nativralist, 1873.

16 THE VOYAGE OF H.M.S CHALLENGER.

that we find the greatest divergence from the normal structure of the Sea-urchin spine,
while it is remarkable that among more recent genera such as the Spatangoids, and
especially the Clypeastroids, we find the simplest types of spines more nearly approaching
the spines characteristic of all the young Echinids of the present day. So that we may
be said to find at one extremity of the series spines with a complicated structure such as
that of the spines of the Cidaridse, and at the other the simple spines of the Clypeastroids
and Spatangoids.

Among the Cidaridje we do not find either in the new species of Goniocidaris or in
Porocidans any important points of structure not previously noticed. Goniocidaris
florigera (PL XXXVIII. fig. 11) presents the characteristic Cidaris features of an outer
crust with a reticulation becoming gradually finer towards the central portion of the shaft
occupied by the " pith " (PI. XXXVIII. fig. llo). Such is also the general structure of
the spines of Porocidaris {P. elegans) (PI. XXXVIII. figs. 12-16) ; the reticulation
extending from the crust towards the centre is somewhat coarser than in Goniocidaris,
and the central space occupied by the irregular reticulation of the pith is comparatively
greater. In the sections of one of the large elliptical spines the crust is comparatively
thin, and four or five of the outer lines of reticulation occupy the space next to the crust,
the rest of the central space being filled with the pith (PL XXXVIII. fig. 15). In
Salcnia {Salenia hastigera) (PL XXXVIII. fig. 10) we find an outer crust as in the
CidaridiB, and the same coarse reticulation of the shaft towards the centre which we
find in Porocidaris ; the central pith is quite hmited in extent.

In Ccelo2)leurus we have, as in the Cidarida3, a great development of the close inner
reticulation of the shaft (PL XXXVIII. fig. 7) with a ring of large foramina round the
central pith (see also section of spine of Ccelopleurus Jloridanus, Eevis. Ech., pi. ii.' fig.
15) with an outer crust much as in the Cidaridae and Salenidaj ; this is the structure of
the large curved primary spines. In smaller spines the central part of the shaft is com-
posed of larger reticulations and a more irregular reticulation (PL XXXVIII. fig. 8) ;
while in the smaller spines we find a very open central reticulation passing directly into
the ill-defined outer crust (PL XXXVIII. fig. 9). This structure of the spines closely
resembles that of the flattened spines of Podocidaris (Revis. Ech., pi. iv. fig. 15), in which
the outer crust is reduced to a very thin layer except where it forms the projections on
the extremities of the lines of well separated reticulating spokes. In Plate XXXVIII.
fio". 9, the line of demarcation between the outer crust and the coarse reticulation of the
shaft is indistinct, and it is only occasionally that in spines like these the outer crust can
be recoo-nised and seen to have the essential characteristics we find in the sections of
Plate XXXVIII. figs. 7, 8 ; so that the Arbaciadse, as far as the structure of the spine is
concerned, may be considered to form the passage between the Cidaridse and the
Echinidse, that is, they have an outer crust as in the Cidaridse and an inner pith, but the
spokes show a tendency to assume a rudimentary monocyclic arrangement, pomting to

REPORT ON THE ECHINOIDEA. 17

that of the Echinidse. Among the new genera of the Diadematidae, the spines of
Micmpyga are found to be closely allied in structure to those of Astropyga, but with a
comparatively larger central foramen and a greater number of calcareous wedges
(PL XXXIX. fig. 1) ; while a section across the swollen tip of a spine of the actinal sur-
face (PI. XXXIX. fig. 2) shows that the solid wedges are reduced to a mere sheath with
an inner ring of closely-packed cells arranged in radiating lines, with a dense reticulated
central pith.

In Asindodiadema we find indicated, by the structure of the spines as well as by the
structure of the test, the afiinities of the genus with the Cidaridse. We find the outer
row of calcareous wedges characteristic of the Diadematidse (PI. XXXVIII. figs. 17-1 9),
with the coarse reticulation of the contents of the shaft as in Porocidaris and Salenia,
and the pith of the central part formed of large and coarse reticulations.

Mackintosh ^ has already given the structural features of the spines of Asthenosoma.
The structure of the spines of Phormosoma (PI. XXXVIII. fig. 4 ; PI. XXXIX. figs. 3-9)
agrees in the main with that of Asthenosoma. These show close affinity on the one side
to the Diadematidaj (PL XXXVIII. figs. 1, 2, 4, 5, 6 ; PL XXXIX. fig. 6), and on the
other to the Arbaciadse, in the large irregular I'eticulation characteristic of the interior
of the shaft (PL XXXIX. figs. 3-7).

Mackintosh has also figured the same open reticulation in the central part of the
shaft of the spine of Ecliinothrix, and has called attention in that genus to the vari-
able character of the solid calcareous wedges forming the outer sheath of the spines
(compare PL XXXIX. figs. 3, 4, and 6). Among the Echinidse, even this structure of the
interior of the shaft is still found in Pseudoholetia (PL XXXIX. fig. 11), and it also exists
among the Clypeastroids in spines either with or without a central cavity (PL XXXVIII.
figs. 21, 22 ; PL XXXIX. fig. 19). In fact the spines of the genera of the Clypeastridae,
which I have thus far examined, Encope, Mellita, and Clypeaster (PL XXXVIII. figs.
19-22), are interesting from the decided afiinities they show to the Echinidse in the
small number of the solid wedges of which they are composed, and in their great
resemblance to the monocyclic types of structure of the Triplechinida3, only that in the
Clypeastridge the shafts are foraminated. In the Petalosticha a similar large foramen exists
in the majority of the genera (see Pis. XXXVIIL, XXXIX.), and with the exception of the
genera Hemiaster, Argopatagus, and Rhynchopygus, in which the wedges resemble more
those of the Clypeastroids, we find that the outer ring of large wedges is generally made
up of triangular pieces with a rounded apex towards the inner foramen ; these wedges are
few in number, in some of tlie genera not more than nine (PL XXXIX. figs. 12, 28, 30,
34, 36). This appears to be the general structure of the spines of the Pourtalesise, and
the allied genera, while in the Spatangoids proper, such as Lovenia, Breynia, Eupatagus,
and the Ananchytid-like Homolampas and Linopneuste-s, the outer ring is made up of a

' Trans. Roy. Irish Acad., xxv., 1875.
(ZOOL. CHAU.. EXP. PART IX. — 1881.) I 3

18 THE VOYAGE OF H.M.S. CHALLENGER.

greater number of wedges. This outer ring is separated from the inner foramen by an
inner ring in which the reticular tissue is very close, as in Simtagocystis, Cystechinus,
and Pourtalesia (PL XXXIX. figs. 28, 37), or in which it even fills the whole interior of
the shaft, as in Cystechinus and Urechinus (PI. XXXIX, figs. 28, 30), or is in the normal
Spatangoids separated from the central foramen by an inner ring of more or less distinct
wedges, the continuation of the larger ring, as in Lovenia, Cionohrissus, and Hemiaster.
In some of the genera we find the reticular structure reduced to a minimum, as in
Echinocrepis (PI. XXXIX. fig. 32), and in Periaster (PL XXXIX. fig. 38). From the
examination of a number of genera of Clypeastroids and of Spatangoids, there seems to
be far less diversity in the structure of the spines in the genera of these two groups
than we find in the Desmosticha.

Chaeacter of Systematic Affinity of Allied Groups of Echinoidea.

In endeavouring to trace the affinities of the comparatively small number of fossil
and living Echinids, it may perhaps be as well to state numerically what we are trying to
do, and to show once for all how futile it must be to carry on the attempts which have
become so fashionable of tracing the genealogy of this or that group of animals. Very few
are so well known from their comparatively unbroken palaeontological history as the
Echinoidea and none are at the same time limited to so comparatively small a number
of species, both fossil and recent. In order to limit the problem still more, we will take
it for granted that we may neglect withm each genus specific difi'erences as not affecting
the case, and take alone the fossil and recent genera, which we will assume to be for
the present not more than 225, represented by 200U fossil, and less than 300 recent
species.

The genera of the present epoch — say 107, with 300 species — represent the possible
combinations of but a small number of Echinoidea, taking into consideration the number
of terms which are variable, which are (in a general way only, of coarse) : — the apical
system, the actinal system, the genital plates, the ocular plates and the anal plates, the
coronal plates, the ambulacral and interambulacral areas, the poriferous zone, the primary,
secondary, and miliary tubercles and then- corresponding spines, the modifications of the
poriferous zone near the apical and actinal systems, and on the test ; the fascioles, the
jaws, the alimentary canal, the position of the apical system, of the anal system, of the
actinostome, and the modifications of the same. "We wiU say twenty variables which
may be, of course, combined in all possible ways one with the other, and which are
capable in their most restricted limits of at least 2^' combinations ; and when we re-
member that in the 225 genera which we have thus far recognised, we may imagine
any one or all the twenty variables affecting the relationship of each of the genera, it
seems somewhat hazardous, to say the least, to attempt anything beyond the broadest

REPORT OX THE ECHINOIDEA. 19

indications of the outlines of the relationship ; and the very fact that this systematic
relationship can still be traced so satisfactorily, not only at the present day, but even
in past geological periods, shows us plainly that this range of variations of our twenty
variables is far less great than is possible, and is kept within comparatively narrow
bounds, otherwise the possible combinations would far exceed our ability to trace them.

In fact, in many classes of the animal kingdom the task of tracing their affinities
and reducing them to the factors from which they originated by following the combina-
tions, appears on the face of it a puzzle far exceeding our ability to cope with, and we
might as well recognise the very narrow limits within which this problem has any
solution. We are brought at once face to face with the number of definite things which
we are able to carry in our mind at one time ; this number is quite limited compared
to the possible combinations which even the smallest number of variable factors repre-
sented by the changes the component structural features of any small group of animals
may assume. Supposing that for twenty years we became acquainted with one species
a minute for ten hours a day, we should not know as many possible combinations as can
be formed out of ten such variables as I have mentioned, which affect radically the
facies of any one of our 225 genera of Echinoidea ; and taking it for granted that the 2300
known species of fossil and recent Echinids are the only combinations which become
sufficiently permanent to have transmitted their principal characteristics for a certain space
of time sufficiently long to be entitled to recognition as distinct species. We must also
remember that the affinities they represent are the result of a far greater number of
possible comliinations than those to which I have referred, and that even a limited num-
ber of species like this baffies all our attempts at indicating these affinities, except in
the most general way ; or, putting it in a different manner, we are attempting an integ-
ration within very distant limits, and are, of course, trying to solve a most difficult
problem, which is not a whit nearer its solution by being presented in the customary
diagrammatic form of a genealogical tree, no matter how satisfactory this mode of
presenting the affinities of the group may appear to its author. But I wish at the same
time to be distinctly understood as not calling in question in the least the theory of the
direct succession of the Echinids of the present epoch from those of the Chalk, in spite of
the hopeless nature of the attempt to represent this succession, either diagrammatically
or descriptively.

Relations of the Jurassic Echinoidea to the Echinid Fauna of the present day.

Starting from the Jurassic Pygaster, which stUl has the closest possible relations
to the Desmosticha, in which the anal system has passed into the odd posterior interam-
bulacrum, we can readily trace the systematic connection to such forms as IIoIecti/2)iis,
Discoidea, Corwclyptis, in which the true Clypeastroid features are more and more

20 THE VOYAGE OF H.M.S. CHALLENGER.

developed until the appearance of tlie Fibularinge which lead us directly to the Echinan-
thidse on the one side, and on the other to the Scutellidse, through such genera as Mor-
tonia ; Eddnocyamus being the genus in which the clypeaster-like petaloid nature of the
ambulacra first appears.

From the time of the appearance of Galeropygus, Hyhoclypus, and Pyrina, we
can readily trace the systematic connection of genera which lead on the one side
to the slightly modified Cassiduloids of the present day, such as Echinoneiis and
Echinolampas, the Pyrina types showing evident relationship to the Discoidese on the
one side, and the Echinolampadee on the other, while Hyhoclyims may well be regarded
as the forerunner of the Ananchytida3 and CoUyritidse, the forms of which are still repre-
sented at the present day, and of the Echinobrissinae which have also survived to the
present epoch, while from the Toxasteridae and the like we pass to Hemiaster, which
may well be considered as the oldest of the Spatanginae proper, allied through Micraster,
to the Holasteridse, and to which it is not difficult to trace the relationship of all the
living genera of Spatangoids. Should we go back to the earliest groups of Echinoidea the
Palseechiuidse, let us see how far they show affinities to Echinids now living. In the first
place the whole mode of comjiosition of the test is eminently crinoidal from the great
multiplicity of plates. It certainly is interesting to find in these earliest Echinids so close
a structural affinity in the arrangement of the interambulacral plates with the interradial
plates of Crinoids, showing how far-reaching has been Loven's generalisation in which
he compared the apical system of the Echinids to the six primary plates of the calyx of
Crinoids. And finally, in a still more general way, we can trace in the embrj'o
Echinoderm of the difierent orders, whether it be a Starfish, an Ophiuran, a Sea-urchin,
a Holothurian, or a Crinoid, the typical structural features which underlie them all.

We trace the existence of the earliest crinoidal structures in the persistency of the
central plate with its five radial plates in the embryo Echinoderms of all the orders.
We follow in the irregular arrangement of the plates of the dorsal surface of Starfishes,
in the repetition of the joints of the arm-plates of the Ophiurans, in the great number
of interambulacral plates composing the test of the earliest Sea-urchins, and of many
Holothurians, modifications of the branching of the arms of the early Crinoids. The
somewhat indefinite distinction of the ambulacral and interambulacral plates in the
embryos of Echinids, Starfishes, and Ophiurans dates back to the earliest Cystideans, in
which the presence of an apical and anal system still further obscures the natiu-e of the
areas. Thus it is that structural features which have apparently disappeared reappear
again suddenly, seeming to have no connection with the types immediately preceding
them, from the peculiar combination of characters which have remained persistent down
to that moment. Yet when we come to analyse the individual characters thus combined,
we generally are able to trace them all as modifications of structural features indicated
in older periods, but combined together, perhaps, in so novel a way as at first to defy

REPORT ON THE ECHINOIDEA. 21

analysis. These types thus seem on that account to have been introduced suddenly,
perhaps, from the great prominence assumed by any one of the Echinodermal structural
characters. Characters of very different degree of prominence in the older tj-pes, which,
slightly modified, might radically affect the structural features of any group.

The modifications of the anal system, of the genital and ocular plates of the test, of
the poriferous zone of the actinal system, of the jaws, and so on, do not go on pari jyassu,
but, on the contrary, vary not only in every sub-order, but in every family and genus ; con-
sequently, modifications of the coronal plates which affect greatly the outline of the test,
and culminate in the Spatangoids, may be combined with other features of very little
systematic value in that group such as the position of the anal system. In the same way
in the Clypeastroids, the structure of the ambulacra, so widely different from that of the
Desmosticha, is found combined with jaws, and again in the Spatangoids a very simple
ambulacral system may be combined with an arrangement of the coronal plates, showing
the greatest degree of specialisation. We cannot hope, therefore, to trace the develop-
ment of any type through a series of forms, each slightly different from its predecessor ;
we must only expect to be able to follow the changes of a single feature, and study it
in its combinations with other features, combinations which from their very nature can
never form an unbroken series, as their terms are not synchronous ; combinations which
can never be links in any chain beyond the link formed by any one special character in
tracing its modifications alone.

It is only in the Archseocidaridse that we find in the structure of the poriferous zone
structural features which have remained unaltered to the present day in all recent
Spatangoids, viz., the simple pairs of pores which we find in the Cidaridse, in the Clypeas-
troids, and in the Spatangoids ; in the Palseechinidse we find small tubercles characterising
a whole group of genera ; this structural feature, the absence of permanent primary
tubercles, still exists at the present day in the highest of our Petalosticha, and is found
uninterruptedly in genera living from the oldest time to the present day.

The apical system which we find in the Palseechinidse still occurs at the present day,
but little modified in the Cidaridse, Arbaciadse, Diadematidse, and the tendency to throw
the anal system outside of this system is already hinted at in the excentric position of
the anal opening in the anal system ; and the compact abactinal system so characteristic
of the recent Spatangoids and Clypeastroids is already foreshadowed in the encroach-
ment of the madreporite on several of the genital plates. The specialisation of the plates
of the two areas, which takes its greatest development in the petaloid ambulacra of the
Petalosticha, can also be traced in a rudimentary form in the double ocular pore of the
ocular plate of the abactinal system, the structural features characteristic of the mode of
junction of the coronal plates of the Desmosticha, and of the Petalosticha, is also to be
traced in the construction of the coronal plates of the test of the Palasechinidse. The
characteristic subdivisions of the test of the Desmosticha into actinostome, coronal and

22 THE VOYAGE OF H.M.S. CHALLENGER.

abactinal regions also exists iu these earliest Echinoidea, though it is so modified as to
show us how the existence of but a single peristomic system [Bothriocidaris) gradually
passes into the Palceechrnus stage, next into the Cidaris stage, and finally the Echinus
stage, and also how it is possible for the peculiar development of the test of the Petalos-
ticha even to be foreshadowed in the absence of lines of demarcation between these systems
in the Palseechinidse, and finally, how the existence of an anal system in one of the inter-
ambulacral areas, while calling to mind an eminently crinoidal structural feature, yet at
the same time shows the intimate relationship there may have existed between the
earliest Spatangoids and the immediate successors of the Cystechinidae, which thus also
may be the precursors of the excentric development of some of the Desmosticha, and of
the whole of the Clyi^eastroids and Spatangoids.

If we examine in the same manner any one of the structural features which have
once made their appearance, we find that, without exception, they are either persistent to
the present day, or can be traced in a somewhat modified form in some one of the types
now living, though the peculiar combination of any definite numljer of these may have
disappear; d, and thus radically new elements may seem to have been introduced into
certain periods, which are after all only excessive modifications of a single element of
structure, which in other forms remains unmodified. This will explain, perhaps, more
vividly than any systematic descriptions of aflinities the subtle connections which close
examination of almost any genus of Sea-urchins at a special period shows not only to the
past but also to the future, and the endless links which can readily be traced by a
careful analysis between apparently totally disconnected types. Let us take as an
example one of the most recent genera, — the genus Sputangus, — and see how far back we
can trace the structural features, modified so as to be characteristic of Spatangus.

The compact abactinal system we can, as I have already stated, trace to the encroach-
ment of the madreporite upon the difi"erent genital plates, and the gradual driving out of
the anal system into the odd interambulacral zone ; or we may go further back and trace
this asymmetric arrangement back to its crinoidal afiinities, this unequal development
of the difi'erent radial and interradial zones dating back to the earliest Echinodermal
structure, and being also naturally connected with the excentric position of the apical system
of the actinostome, and the elongation of the test. The strong contrast between the
actinal and abactinal surface goes back to the existence of the earliest Desmosticha. The
existence of large primary tubercles dates back to the Archseocidaridse, that of small primary
tubercles uniformly distributed over the test goes back to the Palseechinidje, the j)resence of
spines of two difi'erent kinds is as old as the earliest Sea-urchin, as well as the specialisation
of certain parts of the poriferous zone, and the existence of a specialised actinostome.

The development of an actinal plastron dates back to the Galeritidge, to the first
disturbing element which the introduction of the anal system into the odd interam-
bulacral area brought in, and connected with that comes in the development of an anal

REPORT ON THE ECIIINOIDEA. 23

plastron, of an anal snout, of a beak or rostrum, and the formation of an actinal lip ;
connected with these beaks and plastrons are the accumulation along certain lines
of bands of miliaries, the fascioles, which can be traced far back in the formation of the
so-called miliaries in the first j)lace, and their accumulation at certain points, and finally,
their enclosing certain definite areas. If we trace the existence of the slight groove of
the anterior part of the test, we go back to the Chalk, and the time when the odd
posterior ambulacra began to be developed at a difi'erent rate from tlie others, and to
retain its primitive character. The petaloid structure of the lateral ambulacra dates back
to the Jurassic period, when the ambulacral areas above the ambitus differed in their propor-
tions from those of the actinal surface of the test. The petaloid structure of the ambulacra
adjoining the actinostome began with the oldest Cassidulidse, and the simple ambulacral
pores which connect the actinal and petaloid ambulacral plates we find in a part of the
ambulacral zone in the earliest Cretaceous Spatangoids. But the other characters with
which the various structural features still found in Spatangus are connected in the
older genera where they occur are of a very diSerent degree of intensity, and have many
of them developed in directions which no longer occur, and have formed types which
have become extinct, though the special structure which has been modified still exists.

The peculiar internal appendage which represents the auricles in Spatangoids, and the
whole dental system, is reduced to a simple spur, and is the only trace of the complicated
dental aj^paratus which we find in the oldest known Echinids, and which in another
direction has remained but little modified up to the present day. Taking in a similar
way one of the most characteristic of the older genera, Ananchytes, we can also trace
backwards to their first appearance, as we have done for Spatangus, the genera in which
the characteristics of the genus Ananchytes are first developed ; but we can likewise trace
in Ananchytes its affinities to the recent Spatangoid genera, and find in the structure of
the apical system of the amljulacra, of the anal system, of the actinal plastron, and of
the actinostome, indications of lines of development which date back to the genus
Ancmchytes, and which are still to be traced at the present day even though Ananchytes is
at the present time extinct. Another such characteristic genus is Pygaster, in which the
whole line of the Clypeastroids is to a certain extent foreshadowed, although if we
compare the Clypeastroids to the earlier Echinids, we shaU find a far greater number of
identical points of structure than when comparing such a recent genus as Spiatangus.

Adopting the other method, and tracing the development of a single structural feature
at a time, such as the growth of the poriferous zone, from the simple paired zone to the com-
plicated ambulacral zone of a Spatangoid, we shall find that the most primitive ambulacra!
zone known still exists side by side with the existence at the present day of the resultants,
if we may so say, of all the combinations which have taken place. In the same way the
earliest modifications of the coronal plates of the Palseechinidse are found to-day to exist
in several of the recent Desmosticha, along with a test made up of such a sj)ecialised set of

24 THE VOYAGE OF H.M.S. CHALLENGER.

coronal plates as we find in Moira. The actinostome of the Palseechinidse still exists side
by side with the anomalous actinal system of Palceostoma and the Pourtalesise. and the
apical system of the Cidaridse is contemporaneous with the extraordinary combination of
the apical and anal system of the Pourtalesite, and spines very similar in structure to
those so characteristic of the Palgeechinidse are found in the same period with the spines
of the Cidaridse, ofthe Diadematidse, of the Clypeastroids, and of the Petalosticha.

What has once been gained is never totally lost, it always reappears, not in the
previous form but in a slightly modified one, sufficiently preserved to show its systematic
connections, and hence the hopelessness of the task to do more than hint at the infinite
number of relations which the types of the present day hold to those which have preceded
them — relations which witli each succeeding formation become more and more difficult
to trace in proportion as our knowledge of the older formations is more accurate.

The existence of teeth in most groups of the Echinoidea, no matter how distantly
related, is one of the most striking examples of the persistence of a structural feature
once introduced, and of its development or modification entirely independent of other
accompanying characters. The rate and direction of development of the teeth, of the
modifications of the ambulacral system, of the coronal plates, of the anal and actinal
systems, do not go on imri passu when once a slight modification has become introduced,
and thus it is that we have in some of the earlier groups, such as the CoUyritidas and
Clypeastridse, which exist side by side, a widely difi"erent degree of complication of
structure in the arrangement of the coronal plates, in the structure of the actinostome,
in that of the apical system, of the ambulacral system, which have all developed in
difiereut directions from their first origin, so as to produce in the one case the
CoUyritidae, and in the other the Clypeastridae. Thus it is that among the Clypeas-
troids we find genera with very powerful jaws side by side with genera in which the jaws
attain but a slight development, whde other characteristic features of the group, such as
tlie arrangement of the coronal plates, the degree of specialisation of the petaloid
ambulacra, and the structure of the apical system, may be nearly equally developed.

Thus it is that among some of the Echinolampadse we find a prominent auricular ring,
while it is wanting in closely alhed genera. In the same way, in some Spatangina, the
large spur developed close to the actinostome in some genera is not found in theii" closest
allies. It is to this same variation in the degree of development of the ambulacral system,
combined with a difi"erently developed anal system, coronal plates, fascioles, and actino-
stome, that we owe the great diversity we find in the recent genera of Spatangoids, and
it is to their predecessors in time in the Tertiaries, the Chalk, the Jura or often far earlier,
that we must look for the appearance of the structural features which, with the special com-
binations of structural features which may exist at any one period, give us the facies of the
time. We must remember, while making our comparisons, that these structural featui-es,
when once they have originated, may either continue as a persistent type of structure

REPORT ON THE ECHINOIDEA. 25

with but slight modifications to the present day, or at the same time may become
modified in endless ways, and form the innumerable combinations with other structural
features which have given to the Echinid fauna of any period or to that of the present
day its typical features.

Connection between the Cretaceous and the Recent Echinid Faun^.

One of the ver}^ first results clearly indicated by the deep di-edgings of Count Pourtalfes,
and the subsequent investigations of the "Porcupine" expedition, was the antique character
preserved by many of the new genera discovered in deep water, and especially their resem-
blance to Cretaceous genera ; and the study of the Challenger Echinids has brought this
out stUl more plainly.

For the purpose of making the comjiarison of the Challenger Echinids with the earlier
Cretaceous types as comjjlete as possible, it will be interesting to take a rapid review of
the Cretaceous Echinid fauna, and contrast it with the abyssal fauna taken as a whole,
independently of its combinations in time with the littoral and continental types, but
not independently of its combination with those types which extend into the abyssal
fauna either from the littoral or from the continental fauna.

On comparing the genera characteristic of the Chalk with those now found li-\ang, we
find that a considerable number of the latter date back to the Cretaceous period ; and a few
of the Cidaridse, the Echinidse, the Salenidse, the Echinoconidse, and the Petalosticha, even
to earlier epochs, to the Jurassic beds, the Lias, and the Trias. The genera Dorocidaris,
Phyllacanthus, Forocidaris, Salenia, Podocidaris [Magnosia, Codiopsis), Asthenosoma,
Phormosoma {Echinothuria), Temnechinus, Cottaldia, Phymosoma, Holopneustes, Hemi-
pedina, Echimis, Echinocyamus, Fihularia, Echinolampas, Rhynchopygus, Conoclypus
(J.), Echinobrissus, Catopygus, Pygaster, Pourtalesia [In/ulaster) , Hemiaster, Periaster,
are in this category, so that a good proportion of the genera of Echinids still living in
the present epoch belong to genera already existing at the time of the earliest Cretaceous
formations ; and leaving out for the present the genera which have disappeared during
Tertiary times, we find in the Tertiaries, in addition to the above genera, the following
which have continued to the present time : — Arhacia, Ccelopleurus, Echinometra,
Stomopneustes, Strongylocentrotus, SpJuerechinus, Temnop>leurus, Trigonocidaris, Sal-
macis, Amhlypneustes, Toxopneustes, Hipponoe, Clypeaster, Echinanihus, Laganum,
Echinarachnms, Arachnoides, Echinodiscus, Mellita, Encope, Echinoneus, Nucleolites,
Homolampas, Paleopneustes, Spatangus, Maretia, Eupatagus, Lovenia, Breynia, Echi-
nocardium, Brissopsis, Agassizia, Brissus, Metalia, Meoma, Linthia, Schizaster, Moira.

Leaving as genera belonging strictly to the present epoch, which for tlie present we
may take as the result of the existing condition of things, and as the successors of

(ZOOL. CHALl. EXP. — PART IX. 1881.) I 4

26 THE VOYAGE OF H.M.S. CHALLENGER.

the Cretaceous and of the Tertiary forms, the following only : — Stephanocidaris,
Goniocidaris, Diadema, Centrostephanus, Echinothrix, Astropyga, Aspidodiadema,
Micropyga, Colobocentrotus, Heterocentrotus, Parasalenia, Pseudoboletia, Echinos-
trephus, Pleurechinus, Mic)vcyp>hus, Mespilia, Prionechinus, Evechinus, Peronella,
Astridypeus, Rotida, Neolampas, Anochanus, Pcdceotropus, Cionobrissus, Echinocrepis,
Spatagocystis, Cystechinus, Argopatagus, Palceostoma, Tripylus, Faorina.

From our study of the embryonic stages of the Echinidse, the Clypeastridae, and
the Spatangid^, and a comparison of these stages with the genera of the Desmosticha and
Petalosticha which have either succeeded the genera above mentioned, or have lived with
them during the Cretaceous period and have disappeared either during the Cretaceous or
the Tertiary periods, we find no difficulty in tracing an unbroken systematic connection from
the earliest Cretaceous beds to the present time. But this connection is so complicated,
and ramifies in so many directions, that it must be hopeless, even with the small number of
species of Echinids known, to attempt to do more than to indicate the lines of affinities,
the delicate threads of which we can trace in characteristics of genera which at any
special epoch seem to have little or no structural afiinity. Let us take, for instance, the
genera characteristic of the Chalk, and attempt to trace their connection both backw^ards
and forwards in time.

Taking these genera in their most extended signification, and more especially those
characteristic of the Lower Cretaceous formations, Cidaris, Orthocidaris, Phyllaccmthus,
Tetracidaris, Goniopygus, Codiopsis, Magnosia, Cyphosonm, Pseudocidaris, Orthopsis,
Pedinopsis, Codechinus, Stomechimts, Acrosalenia, Echinothuria, Pygaster, Discoidea,
Holectypus, Pyrina, Clypeopygus, Pyguriis, MetaporUnus, Holaster, Toxaster, and
comparing them in the first place with the genera of the Lias as far as they are known,
we find that, with the exception of Cidaris and Hypodiadema, the forerunners of the
Cidaridse and Diadematidae, not a single form of the Echinidai is represented.

To attempt to explain then- relationship to the earlier types, we may say in a very
general way that the Perischoechinidse early show on the one side a tendency to limit the
number of the rows of interambulacral plates ; and on the other side a decided tendency
to a splittmg up of the ambulacral and interambulacral plates into numerous irregular
rows ; they are thus the only group leading directly to such types as Cidaris on the
one side and to the Echinothuridse on the other, the genera Tetracidaris and Echino-
thuria in the Chalk being the representatives of these two groups of Pateechinid^ ; while
the presence of such a type as Hypodiadema early in the Trias may, perhaps, represent
the reduction of the number of coronal plates in some of the earlier Echinids, w^hUe
retaining the uniform tuberculation so characteristic of the Palaeechinidas, and retaining
at the same time the proportionally broader ambulacral areas of some of the types.
From the time of the Trias the Cidaridse have been a most persistent type, and the changes
the members of the family have passed through are restricted to very narrow limits, with

REPORT ON THE ECHINOIDEA. 27

the exception of the aberrant genera Heterocidmis, Tetracidaris, and Diplocidaris,
which retain more or less Palseechinoid characters while taking on a more modern facies.

The relationship of the Echinothuridge to the Palaeechinidse I have already insisted
upon elsewhere, and their affinities to the recent Diadematidse are most close. The
relationship of Hypodiadema to Diademopsis, Pseudodiadema, Hemipedina, and to the
whole group of Pseudodiadematidse which culminates in the Chalk, and is only very
scantily represented at the present day, is sufficiently near not to need any further
elucidation. On the other hand, the development of the Echinidae is somewhat more
complicated, as the affinities of the genera from which we can trace the development of
the Echinidae, the Arbaciadse, and the Salenidge is very close in the Liasic, the Jurassic,
and the Lower Cretaceous beds; where such types as Acrosalenia, Hemicidaris, Glypticus,
and Phymechinus, show us how readily we may pass on the one hand to the Salenidse,
and on the other to the Temnopleuridse, the Echinidae, and the Arbaciadse. It is, however,
only when the interbranching affinities have not extended in too many directions that
we can still easily follow the systematic connection, which is as close as we can possibly
desire to have it. In fact, it is so extended that we are at a loss to express it satisfactorily.

A few examples will suffice : from the development of Salenia, of Echinus, of Ternno-
pleurus, and of Arhacia, we see that these show a very different degree of complica-
tion in their systematic relations to the genera which have preceded them in time.
The Scdenice retain the simple ambulacral system of the Cidaridse, the small number
of coronal plates, the small number of large primary interambulacral tubercles, the
variable shape of the primary spines, the secondary papillae, the large plates of the
abactinal system, and, as far as these features in the Cidaridae are related to the
Palaeechinidae, the Salenice retain to a less degree the Palseechinid affinities of the
Cidaridae. But in addition to this we find in the Scdenice the presence of a subanal
plate, comparatively large ambulacral tubercles, a slight tendency in the ambulacral pores
to deviate from the vertical arrangement of the Cidaridaj, and in the imbricating plates of
the actinal membrane an apparently very decidedly difi"erent structural feature. These
last-named features are all features which tend towards the Echinidae proper, and which
thus far have not appeared in the older Cidaridae, though we find some of these characters
already foreshadowed in the imbricating membrane of the Archaeocidaridge, and in the
large primary ambulacral tubercles of the Hemicidaridae. As far as Echinus is concerned,
the want of prominence of the principal primary tubercles, as well as the greater uniformity
in the structure of the spines, recalls again the earliest Palaeechinidae, while the modifica-
tions of the ambulacral system also to a certain extent point back to an ambulacral
system made up of a large number of plates, as we find most markedly shown again in
the more recent Echinometradae. The actinal membrane is further altered in the direc-
tion of that of Scde?iia ; we have a smaller number of plates, which in some genera are
reduced to ten, the supports of the buccal tentacles, which are the only remnants of the

28 THE VOYAGE OF H.M.S. CHALLENGER.

former uniform extension of the ambulacral pores as far as the actinostome. In the
structure of the apical system, the subanal plate can still be traced in some of the stages
of growth, while in Temnopleimis it never becomes entirely obliterated. In Temno-
pleurus we might say the Salenid abactinal system was more readily traced, and still
better in Arbacia, while in both these genera the Cidarid features of large primary
tubercles is retained in a different degree, and in Arbacia, in one part of the ambulacral
zone, the arrangement of the pores is of an ancient type, while towards the actinostome
its petaloid structure is eminently recent ; the structure of the ocular plate of Arbacia
leads us back directly to the structure of the ocular plate in the oldest Palseechinidse.

The affinities of the Clypeastridae with the Discoidese are clearly indicated by the
development of the longitudinal axis, which dates from the exclusion of the anal from
the apical system. We readily trace through Pileus, Holectypus, and Discoidea affinities
to Galerites and the fossil Conoclypeidse, while with the appearance of Galerites,
Fihularia and Echinocyamus we have the element of the Clypeastridae and Scutellidse ;
and their relationship to the Cassidulidse is well shown in the simple ambulacral system
of some of the genera, and the rudimentary auricles still to be traced among the
Echinolampadse, while the affinity of the earliest CassiduHdas, Hybodypus, Galerop)ygus,
and the Uke, to Pygaster, which culminate in our day with but slight modifications in
Echinoneus, show how clearly related the earlier Spatangoids were with the genera to
which the Clj-peastroids are most closely related, which in their turn still show a most
unmistakable relationship to the Desmosticha, so much so that it seems difficult to say
whether some of the Echinolampadae of the present day are not more closely related to
the Galeritida3, from the slight development of the petaloid system and the presence of
jaws or of rudimentary auricles.

Already, in the Jura, Pygaster shows the method of the passage of the anal system
from the interior of the anal ring to the odd interambulacral space, and we find genera
such as Holectypus and Discoidea, in which it occupies in succession all possible positions
between the apical system and a place close to the actinostome ; and the passage once
effected in the Clypeastroids, we readily go from a mere circular or elliptical opening placed
either in the axis, or obliquely or transversely to it, to an opening in a slight groove or
a more or less deep groove occupying this same odd interambulacral space, having its
climax in the Echinobrissinse, and then we most naturally pass to an opening holding
a certain relation to a more or less distinct beak which, combined with the subanal
plastron enclosed by the subanal fasciole, we can gradually trace from a simple plastron
flush with the test, as in the earliest Holasteridse, to the Echinocardise, to the Brissinse, and
finally to the Pourtalesise, to a plastron extending as a slight beak below the anal system,
and finally forming a more or less distinct snout ; and when this is combined with the
deep anal groove of other Spatangoid genera we get the remarkable forms such as we
have described as belonging to the Pourtalesise.

REPORT ON THE ECHINOIDEA. 29

The type of Holectypus with its regular outline, its buccal cuts, the anal system on
the actinal surface, and the diminution of the size of the tubercles to uniformity in the two
areas, the restriction of the poriferous zone to a single vertical row, all tend to show that
the tendency to the Clypeastroids is already highly specialised. The existence of such
forms as Pyrina with their simple ambulacra leads directly to the Nucleolidae and Echino-
lampadse. On the contrary, we can only obtain such forms as the present deep sea types
from the earlier Cretaceous types like Infulaster, and their derivation from such forms as
Colhjrites seems probable, if we take into account such extraordinary forms as have
been figured by Ooster (Echin. Alp. Suisses, pi. x. figs. 1-4), as Dysaster calceolatus
(see also de Loriol, Echinod. Crdt. de la Suisse, pi. xxxiii.).

When we take the Spatangoids of the Chalk, they lead us directly through the Palseos-
tominse and the CoUyritidae ^ to the Ananchytidse, which have persisted to the present
day ; and also to the Spatanginse proper, represented by but few genera, as Mkraster,
Hemiaster, and Prenaster, which already possess the structural features characteristic of
the recent Spatangoids. That is, we find genera with a peripetalous fasciole, a subanal
fasciole, sunken ambulacra, petals of different degree of development, spines specialised
on certain areas of the test, a trace of a sunken anterior groove, of an anal beak, of an
actinal plastron, of a snout, of a lateral fasciole, and of a specialisation of the primar}^ and
secondary tubercles. But, of course, the extent to which these features may be developed
in Tertiary and recent genera contrasts often strikingly with the rudimentary nature
of the structural features found in the Cretaceous or Tertiary genera. The simple
actinostome of the Pateostominse is combined with a well-marked specialisation of the
ambulacra above the ambitus, the petaloid feature of the early Spatangoids which appears
later than in the Cassidulidse ; while in the Ananchytidse the well-developed labium of all
the more recent Spatangidse is combined with a comparatively more rudimentary state
of the ambulacral zones.

Among the Cretaceous genera, Hemipneustes and Ennalaster are extremely instructive.
They show, perhaps better than any others, the passage which exists between the earliest
Spatangoids with more or less petaloid ambulacra, and the older Spatangoids without
petals, and in which the ambulacra have the same simple structure from the apical
system to the actinostome. In both these genera the petaloid structure Ls limited to the
posterior poriferous zone of the lateral ambulacra ; the only recent genus in which a
similar structure still exists is Agassizia. In this genus, however, the posterior lateral
petals are normally developed as in other Spatangoids, or perhaps we must consider this
as the last trace in normal Spatangoids of the simple condition of the ambulacra, such as
we still find it in the Pourtalesise. It is specially interesting to compare these genera first
to the Ananchytidfe, then to the Toxasteridse, and finally to such recent genera as Genico-
patagus, Homolampas, Argopatagus, and the like. These comparisons lead us to detect

• The Collyritidse in their turn showing most striking affinities to such genera as Hyboclypus and Galeropygus.

30 THE VOYAGE OF H.M.S. CHALLENGER.

afl&nities in all possible directions, with the highly petaloid ambulacra of the Spatangoids,
with the simplest ambulacral petals of the earliest Spatangoids, or with the embryonic
ambulacra of the Pourtalesiae proper.

Comparison between the Tertiary and Recent Echinids.

In comparing the Tertiary fossd Echinids of the European beds with the species now
living in the West Indies, we cannot fad to be struck with the similarity existing between
them. It is well nigh impossible to distinguish the species, and even Cotteau hesitates to
consider them as specifically distinct. Compare thus the species of- Cidaris, Clypeaster,
Echinolampas, Schizaster, and Brissopsis, which are found in the Tertiary beds of Malta,
and are no longer found in the Mediterranean, having undoubtedly disappeared from there
as soon as the Mediterranean became a closed sea, and the temperature of the water became
raised above that of the ocean ;^ while, on the contrary, where the oceanic conditions have
not undergone any such great change, we find a remarkable identity in the genera of the
Tertiaries and of the surrounding deep sea, as can easily be seen by comparing the
Tertiary West Indies types '^ of Cidaris, of Echinolampas, of Agassizia, of Brissopsis, of
Schizaster, of Ettpatagus, oi Periptneustes (Meoma), oi Hemiaster, of Conoclypus, and of
Echinanthus, with the species of the same genera now found in the deep waters of the
Caribbean Sea and GuLf of Mexico. The presence of Clypeastroids in the Tertiaries of the
Mediterranean and Western France forms the connection which once must have existed
between the American Clypeastroids and those still found on the West Coast of Africa,
and extending from the Eed Sea to the Western edge of the Pacific realm. A trace of
this old connection is stiU shown at the present day in the existence of a species of
Mellita and of Moira in the Red Sea.

Forbes, in his Monograph of the Echinodermata of the British Tertiaries, has figui-ed
under the name of Echinarachnius Woodii two species, one of which is probably a
Rhynchopygus or a very flat Niicleolites ; the other, a genus closely allied to one of our
deep-sea Pourtalesice ; it has the peculiar snout, thus far known only in that group.
Tlie relationship of the species of the older crag to the southern and eastern types was
already then insisted upon by Forbes ; while the newer crag manifests a more definite
connection with the present Fauna of Great Britain, and in the Pleiostocene of Norway
and North America we find the common StrongyJocentrot us drobachiensis, which is truly
an Arctic and boreal species, both in the Atlantic and Pacific Ocean.

Laube^ describes from the Tertiary beds of Austrian-Hungary a species of Schizaster

' A similar westward extension of the Tertiary corals of Sicily has been shown by M. Poiirtalfes, who also finds
Tertiary Sicilian corals still li\'ing in the deep waters of the Caribbean Sea.

'^ See principally Cotteau, EchLnides d'Angmlla ; Guppy, West India Tertiaries.

2 Dr Gustav C. Laube, Die Ecliinoiden der Oesterreichisch-Ungarischen oberen Tertiarablagerungen K. K. Geol.
Reichs Anstalt, Abhandl, v. Heft, No. 3, 1871.

REPORT ON THE ECHIXOIDEA. 31

closely allied to the present Mediterranean species Schizaster canaliferus ; under the name
of Echinus dux, a species which has aU the facies of Sphwrechinus with the structure of
the poriferous zone of Echinus proper; also Echinocyamus, which varies to such an extent
that it is well-nigh impossible to separate many of the more recent Tertiary forms from
the species still living. The species described by Laube is remarkable for showing in so
large a species the sculpture in the line of the horizontal sutures characteristic of the young
stages of Ecliinocyamus such as I have figured in the Ee vision of the Echini, pi. xiii.,
while the presence of such a tj-pe as Amphiope elUptica (Echinodiscus) shows evidently the
former extension of the genus far to the eastward of its present range ; and the existence
of species of Schizaster like Schizaster leithanus (Laube), with very decided Hemiaster
affinities, enable us readily to see how Hemiaster may gradually have been modified into
the typical Schizaster of the present day. Spatangus austriacus seems from Laube's
figures to be more closely allied to Spatangus raschi than to Spatangus purpureus,
while Brissomorpha is evidently an entirely difierent type, which unites, like many of the
deep-sea Spatangoids lately discovered, characteristic features of several genera. It has
the greatly developed posterior interambulacrum forming a regular beak covering the anal
system somewhat as we find it iu Echinocrepis, but it has the labiate actinostome of
Brissus, with the outline from above of Echinolampas ; its representative in the
present day is Nacopatagus, with which it is most closely allied. Manzoni and Mazetti
have figured and described in the Atti Soc. Tosc. Sc. Nat., iii. pi. xix. fig. 2, under
the name of Heterobrissus, one of the Spatangoids with ambulacra flush with the test
(but with few pores), which seems to be more closely related to some of the abyssal
genera such as Nacopatagus than any other; and seems to indicate, from the structure
of its petals and the consequent long line of simple pores forming the ambulacral
areas, how the present genera, that is, the whole group of the Pourtalesise wdth simple
pores, originated and came to persist, retaining the embryonic tyj^e through which
all Spatangoids primarily pass, the apetaloid state, which is but slightly advanced in
Heterohriss^is.

When we compare the Nummulitic species of Echinids with those now existing either
in the littoral, or in the continental and oceanic zones of the Indo-Pacific region, we
find that the generic types have continued to the present day, and many species will
undoubtedly prove to be identical, on close comparison of more extensive series of the
large number of Temnopleuridse which characterised the Indian Seas of the Tertiary
beds with those of the present day, as well as with the species of Maretia, Brissopsis,
Hemiaster, Temnechinus, Echinanthus, Echinolampas, and other Cassiduloids, which
have been figured by Herklots, D'Archiac and Haime.

From the excellent descriptions of the Australian Tertiary Echinids of Duncan, of
Laube, and of Tate, we cannot fail to be struck with the existence in the Austrahan
Tertiaries of the genera Eupatagus, Lovenia, Arachnoides, Echi)iohrissus, Fihularia,

32 THE VOYAGE OF H.M.S. CHALLENGER.

Echinanthus, and others, which are in our clay still so characteristic of the i^.ustralian
region.

But there was a time when the peculiar Australian genera of the present day extended
far to the westward. Laube ^ figures a most interesting species under the name of Chry-
somelon vicentice and Chrysomelon pictum, of which most certainly the nearest allies are not,
as he suggQ^ts, Melonites, hwt the Australian generic types Holopneustes and Amhlypneustes.
In addition to the above the species with decided Pacific afiinities are Sismondia planulata
closely allied to Laganum honani and Clypeaster hreunigii to Laganum decagonum, while
Scutella tenera rej)resents the American Tertiary element together with a number of
species of Clypeaster proper and of Echinanthus, which, as is well known, obtained a great
development in the Tertiaries of Southern Europe, as well as Echinolampas, Hemiaster
proper, and Schizaster of a more or less Hemiasteroid facies. From what has preceded, it
is evident that, in making these comparisons between the fossils of a district with those still
found living at great depths in other areas, we at once find how impossible it is to establish
a synchronism from the comparison of identical species in distant formations. Palaeon-
tologists have frequently enough felt the futility of attempting to establish merely upon
palseontological evidence the synchronism between distant beds supposed to belong to the
same formation. This brings us, it seems to me, face to face with the identical problems
we are attempting to solve to-day, when stating that the typical Austrahan Echinids
belong to the present Fauna. What have we to support that assertion ? — A single species
of Fsammechinus, a few Triplechinidae, a few Clypeastroids and Spatangoids, and a
couple of species of Cidaris.

Now, what has taken place in Australia ? AVe may picture to ourselves in other
times and places the gradual extinction of the Cidaridse and of the Clypeastroids ; the total
disappearance of species stiU found fossil, but now no longer living, which connect them
with the Tertiary period, and only the types of Psammechinus, Goniocidaris, and a few
types characteristic of the Indo-Pacific realm, with the present Fauna, whUe the typical
form Amhlypneustes is most e\adently descended directly from the Chalk, and the wider
geographical distribution in space which we have begun to trace among the fossils was
also accompanied by a greater persistency in time ; as dilferent a condition of things as
possible from the state of things of the present day.

From the comparative lists of Corals from the Tertiaries of the West Indies made by
Duncan, it is very evident that the affinities of by far the greater number are with the
recent coral Fauna of the Pacific, the Indian Ocean, and the Eed Sea, with the Miocene
period of the Australian, Java, Indian, and European Tertiaries. AVhat trace there is of
the connection claimed by Duncan to have existed between South Europe and the West
Indian Islands I fail to see. That this connection of South Europe existed with the

' Dr Gustav C. Laiibe, Ein Beitrag zur Kenntniss der Echinodermen des Vicentinischen TertiSigebietes. Denk ;
<l. Kais. Akad. d. Wiss. Wien., xxix., 18fi8.

REPORT ON THE ECHINOIDEA. 33

most south-eastern extremity of the Pacific Ocean we have the fullest possible proof, but
that it extended to the west of the Azores we know not, and we must seek other modes
of connection, perhaps across the short space between South America and Cape Verde
Islands, certainly not by the North Atlantic, but perhaps by the North South Atlantic.
The isolation of the West Indian corals, polyps, and echuioderms dates from the time of
the shutting ofi" of the Isthmus of Panama, and probably by areas of elevation synckro-
nous with the rise of the West Indies. These areas of elevation certainly extended far
to the south on the west coast of South America, where we can trace them in the suc-
cession of the great inland basins forming the great desert of the narrow rainless belt of
the coast, the old sea-bottom now flanked by nitrate beds up to a height of 3000 feet ;
where we also find species of corals identical with those now living, or similar at least to
those of the West Indies.

DESCRIPTION OF THE SPECIES.

DESMOSTICHA.
Sub-order Desmosticha, Haeckel, Entwickel. Gesch., 1866 (emend.).

ClDARlDJE.
Family, Cidahid^ MiilL, Bau d. Echinod., 1854 (emend.).

GoNIOCIDARIDjE.
Sub-family Goniocidarida, Hffickel, EntwickeL GescL, 1866.

Cidaris.
Cidaris, Klein, Nat. Disp. Echin., 1734.

Many attempts have been made to refer some of the recent sul^-genera of Cidaris
to genera composed thus far of fossd species only. With the exception of the species of the
genus Cidaris proper, these attempts must be considered faulty, from the usually im-
perfect state of preservation in fossils of some of the most important characters by which
the recent sub-genera have been distinguished. Such important guides as the nature of
the pedicellariee and the structure of the abactinal system are wholly wanting for com-
parison, and the difiiculty of deciding on the relationship from the test and radioles
alone, is too well-kno'^vai to require further comment. In fact, setting aside Di2:>locidaris,
Porocidaris, and Goniocidaris, which are separated from Cidaris proper by characters
apparently more prominent and permanent than those upon which the other genera
among the fossil or recent species are based, we must consider Dorocidams and Phylla-
canthus as mere sub-genera of Cidaris, convenient subdivisions round which a large
number of recent and fossil species can be arranged. Dorocidaris would include all

(ZOOL. CHALL. EXP. — PART IX. — 1881.) I 5

34 THE VOYAGE OF H.M.S. CHAI.LENGER.

forms with narrow ambulacral areas and long slender serrated spines, while Phijllacanihus
[this subdivision, as I have limited it, is equivalent to Leiocidaris and Rhahdacidaris of
Desor] would include species with broad ambulacral areas, having the poriferous zones
joined by a furrow more or less distinct ; while Cidaris proper would be restricted to
species in which the pores of the poriferous zone are not so connected. But thus
far no characters derived from the many species described, either fossil or recent, can be
given to define these sub-genera with any accuracy. The genus Cidaris has since the
Triassic period been represented uninterruptedly by a large number of species, and as
far as the radioles are known, while some of the types seem characteristic of the
Jurassic or Cretaceous, yet from what we know of the extraordinary variations in the
spines among the recent species, they hardly furnish a safe guide for any subdivision.

In fact, the species of the genus Cidaris, like those of many other genera, present
soon after their appearance an extensive series of variations, showing an extraordinary
degree of plasticity, which has gradually diminished somewhat as we pass from the
Jurassic to the Cretaceous, the Tertiary, and finally the recent species. Among the
latter we still find all the principal types of radioles represented, with the exception of
the round-headed acorn-shaped radioles, like those of Cidaris glandifera, which appeared
with the Triassic Cidaris and died out during the Cretaceous. This is thus far the
only type of radioles of Cidaris of which no analogue exists among the species still
living at the present day.

The family Cidaridse is liy no means so strictly circumscribed as it would seem
from an examination of the living forms alone, and when we come to intercalate such
forms as Acrosalenia, Pseudocidaris, Hemicidaris, and Pseudosalenia, wdth Tetracidaris
and Diplocidaris, we find afiinities developing among the genera allied to the Cidaridas,
pointing on the one side to the Cidaridse proper which preceded them in time, and to the
Pseudodiadematidae on the other side, which have such an extraordinary development in
the Cretaceous formation, the Cidaridae types developing into the small groups of Salenidae
and of Cidaridaj proper which have persisted to the present day ; and the Pseudodiade-
matidse type gradually disappearing and being represented at the present time only by
the Phymosoma group, and not developing into the Diadematidae proper, which are
evidently the successors of the Perischoechiuidae or the Echinothuridse of the Chalk ;
though the structure of the abactinal and actinal systems of some of the Palaeechinidae, as
wiU be seen hereafter, points to a far closer affinity between them and the Cidaridae than
has been hitherto acknowledged. In the descriptions of the young Goniocidaridae we
cannot fail to be struck with their similarity to the St Cassian Cidaridae, and the tests
of the diminutive Cidaridae of the Trias show at a glance embryonic features, such as
the young of all Cidaridae have, which were at that epoch characteristic of the whole
group of Cidaricte.

The small Cidaridfe of the St Cassian are the most perfect emliryonie Cidaridae imagin-

REPORT ON THE ECHINOIDEA. 35

able ; their small size, the gigantic size and often small number of their primary tubercles,
as weU as the peculiar shape of the primary radioles, all remind us of the early stages of
our present Cidaridae to a degi-ee which. can hardly be realised \\'ithout a direct comparison
of the figures of such Cidaridse as are given by Laube (Fauna d. Schichten v. St
Cassian, pis. viii.'' and ix.) with those of some young Cidaridse I have myself figured
(Revis. Echini, pi. ii.'' fig. 7) ; and the variety of form in the radioles found associated with
those in the St Cassian beds rivals the di.sproportions noticed in the spines of young
Echinidse and Cidaridse such as I have figured in the chapter on young Echini in the
Eevisiou (pi. ii.'^figs. 7-13 ; pi. v. fig. 9 ; pi. viii. fig. 16 ; pi. ix. ; pi. x.), and in the Embry-
ology of Echinoderms (Mem. Am. Acad., 1864). It is interesting in the description of the
variation in the shape of the spines which we find in Goniocidaris to see how early in
geological times this variation already existed as a character of the family, and has
persisted to the present day.

The oldest species of Cidaris in the Trias were small species with smooth tubercles,
and the variety of radioles already apparent was considerable. Nearly all the types are
represented, but it is almost impossible to separate them, as there is a gradual passage
from one to the other. There is a great predominance of clavellate types, a great variety
of radioles with secondary spines, and a nearly total absence of the long cylindrical
radioles so characteristic of many of the Cretaceous, Tertiary, and recent species. This
variation in the spines and gradual transition recalls to us embryonic stages where
one and the same species passes rapidly from the state of embryonic species to the state
characteristic of the fully grown individuals. When we come to the Jurassic type of
radioles the varieties are less closely connected. They arrange themselves more easily
into two great types — the glandiarii and the aculei as Desor has named them, —
but we must remember that there are stdl transitional forms, or rather elongated
glandiarii with narrow necks approaching the aculei form of the others, and that
this formation is characterised by tlie far greater development of the elongated type
of radiole than in the preceding formation, their larger size corresponding to the
increase in the size of the test, and the immense development of species charac-
teristic of the Jura which have also mainly crenulated tubercles. This crenulation,
however, disappears again during the Cretaceous period, during which the Cidaridse
have smooth tubercles, but, as is the case also in recent species, do not on that
account carry smaller radioles. On the contrary, the latter are remarkable for their
great length, their greater variety in shape compared with those of the Jurassic period,
and more parti cidarly, as has been so well shown by Desor, for the first appearance of
the spreading into a corolla of the extremity of the spines so characteristic of some
Tertiary genera, and which seems to culminate at the present period in the cupuliform
spines of Goniocidaris. The glandiform radioles attain a degree of extreme development
unknown in the older formations, and they nearly disappear during the Tertiary period,

36 THE VOYAGE OF H.M.S. CHALLENGEK.

which contains mainly types of radioles similar to those of Dorocidaris and Cidaris
proper.

The spines of Rhahdocidaris are of two principal types, one of which, like those
of R. copeoides, has also been found in the spines of a recent species ; the other, like
those of such recent forms as impericdis, approaches more to the fossil types of Phylla-
canthus orhignyana.

Cidaris tribidoides (PI. I. figs. 2, 3, 5, 6).

Cidarites tribidoides, Lamk., 1816, Auim. sans Vert.
Cidaris tribuloides, Bl., 1830, Zooph.

There exist in several of the European museums small specimens of Cidaris, generally
labelled " Africa," resembling the young of PhyUacanthus verticillata, which they have
usually been considered. One or two such young specimens were collected by M.
Bouvier at Cape Verde Islands, and are now in the Jardin des Plantes. I did not
attempt to incorporate them in my Kevision of the Echini for want of sufficient
material.

The Challenger di-edged at Bahia in 7 to 20 fathoms, and also at Fernando Noronha
a few specimens of a Cidaris, which at first sight would readily be mistaken for
PhyUacanthus verticillata (PI. I. fig. 2). On comparing, however, young PhyUacanthus
verticillata with the present specimens, we readily note the following striking diff"erences.
In PhyUacanthus verticillata the verticillations are formed by large prominent lamellae
(see A. Agassiz, Revis. Echini, pi. i.'' figs. 40-42), while in this species there are a few
larger sharper serrations rising irregularly above the general granulation of the shaft, and
concentrated on from three to five swellings along the length of the shaft (PI. I. fig. 3).
Otherwise the radioles and papillae vary in shape much as do those of Cidaris tribidoides,
and bear the same proportion to the diameter of the test, and the granulation is similar
to that of the ordinary type of Cidaris tribidoides. The test of the largest specimen
collected measures 17 mm. in diameter, and differs in no particular from the test of a
normal Cidaris tribidoides of the same size.

Similar young specimens having thus far been observed only in localities where
Cidaris tribuloides occurs, I am inclined to regard them as only a variety of that
species. In some of the Challenger specimens, especially the smaller ones, this abnormal
decoration exists only in a few of the spines, the other radioles do not differ from
those of young specimens of a similar stage of Cidaris tribuloides. The difierences
in the spines of these specimens, and those thus far regarded as the normal Cidaris
tribuloides are not greater than differences with which we are familiar in the
spines of Goniocidaris tubaria for instance. In the section of Cidaris to which Cidaris
tribuloides and Cidaris metularia belong, no such variation of the spines was

REPORT ON THE ECHINOIDEA. 37

known before, beyond the well-known differences between the spines near the actinos-
tome, the smooth spines near the abactinal system, and the typical primary coronal
spines covered with uniform granulation and serration, or the more or less distinct
fluting and serrations of the spines of Dorociduris. The discovery in the Caribbean Sea
of a species oi Dorocidaris {Dorocidaris hlakei, A. Agassiz), with flat fan-shaped radioles,
shows that we may expect, even in the genera of Cidaris with uniform radioles, an
amount of variation in the shape of the spines and their ornamentation fully as great
perhaps as that with which we are familiar in Rhcibdocidaris, Goniocidaris, and
the like.

During the "Blake" expedition of 1878-79, a number of specimens of Dorocidaris
hlakii were collected from different localities. These are extremely interesting as
showing the gradual passage of a long cylindrical tapering radiole, either fluted or not,
with more or less prominent serrations, into a broad flat fan-shaped spine. The
detailed descriptions and figures of these spines will appear in the reports of the
" Blake " Echinids.

Bahia, 7 to 20 fathoms.

Fernando Noronha, shallow water.

St Vincent, Cape Verde, 15 to 20 fathoms. April, 1873.

Dorocidaris (Cidaris).

Orthocidaris, A. Agassiz, 1863, non Cotteau.

Dorocidaris, A. Agassiz, 1869, Bull. Miis. Comp. Zool., vol. i.

^Dorocidaris (Cidaris) hracteata^ (PL I. fig. 1 ; PI. XLII. fig. 1).

Dorocidaris hracteuta, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 197.

This species is the Pacific representative of Dorocidaris papillata, which has such a
wide range in the Atlantic. It is characterised by the small size of the papillae covering
the abactinal area, and the small size of the mammary boss of the primary tubercles,
their smaller number compared to specimens of Dorocidaris papillata of the same size,
the great size of the abactinal area, and the short slender papillae surrounding the base of
the primary spines. The primary radioles are long, pointed, slender, deeply fluted, the
fluted edges more or less serrated (PI. I. fig. 1). The serrations are frequently connected
into lamellae, or in other specimens, those from deeper stations, the serrations are largest
and most prominent on the lower third of the shaft ; they are very distinct, extending
over the whole surface of the spines, and the fluting is scarcely perceptible. The short
slender primary spines of the actinal surface are smooth, and strongly fluted. The largest
primary spines are twice the diameter of the test. In alcoholic specimens the papdlse of
the ambulacral, interambulacral, and abactinal areas are light reddish-brown, the spines

' The genera and species first discovered by the Challenger are all marked with ;ui asterisk.

38 THE VOYAGE OF H.M.S. CHALLENGER.

greyish-yellow, and sometimes iri'egixlarly banded with brownish-red patches. The
difference in the shape of the plates of the abactinal system readily distinguishes this species
from Dorocidaris ixvpillata; the ocular plates are broadly triangular, extending to the
edge of the anal system, which is covered by a smaller number of plates relatively larger
than in Dorocidaris pcq^illata. The whole abactinal system is covered by finer granules
more closely packed than in that species. The ambulacral system is relatively much
narrower, both the poriferous zone and the median interporiferous space. The scrobicular
area is scarcely sunken, the coronal plates are not high. Otherwise, the test closely
resembles that of the Atlantic Dorocidaris ixiinllata, but with less distinct and smaller
secondary and miliary tubercles.

The short-headed long-stemmed ambulacral pedieellarise of Dorocidaris hracteata
differ from those of Dorocidaris papillata in being broadest at the base, supported by a
longer pedicel and a comparatively more slender rod (PI. XLII. fig. 1).

Amboyna, 100 fathoms.

Amboyna, 15 to 25 fathoms.

Dorocidaris (Cidaris) papiUata.

Cidaris papillata, Leske, 1778, KL Add.

Dorocidaris jMpillata, A. Agassiz, 1869, Bull. Mus. Couip. ZooL, vol. i.

The collections of the Challenger show that this sjDecies has an extensive geographical
range both in the Atlantic and Pacific. Its distribution in the Western and Southern
Atlantic corresponds with that of Cidaris trihidoides ; the latter has, however, as yet not
been found in the Eastern Atlantic north of the Cape Verde Islands, while, as is well
known, Dorocidaris pajnUata is found also far north in the North-Eastern Atlantic. The
specimens collected in the Philippine Islands cannot be distinguished from those of the
Atlantic. The deep water forms generally resemble the variety I had described as
Dorocidaris ahyssicola. The whole question of the specific characters of Dorocidaris
papillata having been reopened by the discovery of Dorocidaris blakii, this identi-
fication of the Pacific and Atlantic specimens is of course subject to considerable doubt.

St Paul's Rocks. 70 to 80 fathoms.

Station 24. March 25, 1873. Off Culebra Island; 390 fathoms; mud.

Gomera, Canary Islands ; 70 fathoms.

Station 320. February 14, 1876. Lat. 37° 17' S., long. 53° 52' W. ; 600 fathoms;
bottom temperature, 27° C. ; hard ground.

Station 210. January 25, 1875. Lat. 9° 26' N., long. 123° 45' E. ; 375 fathoms;
bottom temperature, 12'2° C. ; mud.

Station 204. November 2, 1874., Lat. 12° 43' N„ long. 122° 10' E. ; 100 fathoms;
and 115 fathoms; mud.

REPORT ON THE ECHINOIDEA. 39

Pliyllacanthus (Cidaris).

Phyllacanthus, Brandt, 1835, Prod. Desc. An.

PhyUacanthus annulifera.

Cidarites annulifera, Lanik., 1816, Auim. sans Vert.

PhyUacanthus annulifera, A. Agassiz, 1872, Revis. Ech., part 1, p. 150.

Mr P. de Loriol [Mem. Soc. des. Sc. Nat. de Neufcliatel, vol. v. p. 23, pis. iii. to vi.,
Mai 1873] has distinguished as Cidaris liltkeni a specimen closely alUed to Cidaris
anmdifera. The specimens collected by the Challenger of what I take to be (PhyUacan-
thus) Cidaris annulifera, show that the variation of the primary and secondary spines is
much greater than is admitted by De Loriol, after a comparison of the different spines of
the Challenger specimens with those of the Museum of Comparative Zoology I am
unable to distinguish Cidaris liltkeni from Cidaris anmdifera; De Loriol acknowledges
himself the identity of the structure of the test, and bases his principal characters on the
variation of the primary spines. They differ in the same specimen sufficiently to be
taken as belonging either to the typical Cidaris annulifera or to Cidaris liitkeni, and
even resemble sometimes so closely the spines of Stephanocidaris hispinosa as readily
to pass for spines belonging to that species.

Station 186. September 8, 1874. Lat. 10° 30' S., long. 142' 18' E. ; 8 fathoms;
coral sand.

Station 188. September 10, 1874. Lat. 9" 59' S., long. IZ9' 42' E. ; 28 fathoms;
mud.

Cape York.

Phyllacanthiui hactdosa.

Cidarites hactdosa, Lamk., 1816, Anim. sans Vert.

PhyUacanthus baculosa, A. Agassiz, 1872, Revis. Ech., part 1, p. 150.

A specimen from Station 201 is extremely interesting, as it is the only specimen thus
far collected of this species in which all the primary spines belong to the type of Cidaris
proper, resembling to an extraordinary degree the elongated spines sometimes occurring
in specimens of Cidaris trihtdoides. The serrations of the shaft show no trace of the
lamellar arrangement forming a more or less prominent fluting of the tip of the spines
as in specimens of the typical Cidaris hactdosa; neither are there any prominent
serrations or spines on the shaft such as we find on forms usually considered as specific,
viz.: — Cidaris lima, Cidaris instillaris, or Cidaris krohnii, but which I have already
shown all belong to this species. The specimen figured in Revision of the Echini (pi. i.*",

40 THE VOYAGE OF H.M.S. CHALLENGER.

fig. 4) sliows two such spines (the bLack ones on the left) simihir to those covering the
whole test of this specimen.

Samboangan ; 10 fathoms.

Station 201. October 26, 1874. Lat. 7' 3' N., long. 121' 48' E. ; 82 fathoms and
102 fathoms; stones and gravel.

Phyllacanthus gigantea.

Cliondroeidaris girjantea, A. Agassiz, 1863, Bull. Mus. Comp. Zool., vol. i.
Phijllacantlius gigantea, A. Agassiz, 1872, Eevis. Eoh., part 1, ]}. 150.

Ofi" Honolulu Reef.
Phyllacanthus verticillata.

Cidarites verticillata, Lamk., 1816, Anim. sans Vert.
Phyllacantlius verticillata, A. Agassiz, 1872, Eevis. Ech., part 1.

Station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' E. ; 8 fathoms;
coral sand.

Porocidaris.
Porocidaris, Des., 1854, Syn. Ech. Foss., p. 46.
*Porocidaris elegans (PI. Ill, XXXVIII. figs. 12-16 ; PI. XLIV. figs. 6-14).

Porocidaris elegans, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 198.

This species can at once be distinguished from Porocidaris 2>urpurata, Wy. T., by the
facies of the spines (PI. III. fig. 1) and by the structure of the abactinal system (PI. III.
fig. 2). The interambulacral plates of the test also differ from those of Porocidaris 2^ur-
purata in having a larger row of secondary tubercles surrounding the scrobicular circle
(PL III. fig. 5). This is complete only in the first and second of the coronal plates
nearest the abactinal system, the areas becoming confiuent towards the ambitus and
actinostome in the remaining plates. The median interambulacral space also difi"ers
from that of Porocidaris purpurata in having larger secondary tubercles, leaving a space
nearly bare between the secondaries, or only sparsely covered by small irregularly
arranged miliaries. There is a single row of small secondaries regularly arranged in a
vertical line along the median ambulacral space (PI. III. fig. 6.) with a few intervening
miliaries along the median line. The pores are distinct, separated by a prominent
median ridge. The primary interambulacral tubercles are surrounded by a large areola.
They are small, crenulate, except the last foi-med near the actinal system.

REPORT ON THE ECHINOIDEA. 41

The genus Schleinitzia was established by Studer (Proc. Berlin Acad., p. 463),
for a Cidaris in which the anal system is allied to that of Stephanocidaris, the
spines recalling Porocidaris, while the crenulation on which he principally based his
genus recalls Rhabdocidaris ; and it may possibly be that Studer 's Schleinitzia is
after all only a new species of Stephanocidaris or of Porocidaris, more prol^ably
of Stephanocidaris, since S. hispinosa, has crenulate tubercles, and pores joined by
furrows.

Thomson (Trans. Eoy. Soc., 1874, vol. Ixiv., part 2, p. 726), in his description of
Porocidaris purpurata dredged in the " Porcupine " expedition, had already called atten-
tion to the simultaneous occurrence of crenulated and smooth tubercles on the same
specimen. He has figured these crenulated tubercles as existing in his specimen mainly
round the abactinal system (pi. Ixi. fig. 2).

Until the publication of Thomson's paper, which seems to have escaped Studer, it was
supposed that the crenulation of the tubercles distinguished the fossil from the recent
species as a whole. The unsatisfactory nature of this character, however, was well known
from those groups among recent Echinids in which crenulated tubercles occur, and the
impossibility of assigning to it any definite value. In the Diadcmatidee and Pseudodia-
dematidse we find on the same specimens primary tubercles identical in size, which are
either crenulated or not. Loriol has expressed his oj^inion of the variability of this
character as regards fossil CidaridjB, of which the tests are frequently so admirably
preserved as to retain the smallest details of structure. Troschel, in 1877, called attention
to the presence of crenulated tubercles in a new species of Cidaris [Rhabdocidaris recens,
Archiv. f. Nat., vol. xliii. p. 127). Subsequently Troschel (Sitzungsb. d. Nieder Rhein
Gesell., Dec. 8, 1877) returns to the same species, caUing attention to the fact that Loriol,
on examining his specimens of Cidaris annidifera and Cidaris liltheni, found that in
both specimens the tests were covered with primary tubercles of which some were
crenulated and others smooth. Troschel at the same time shows that his Rhabdocidaris
recens is closely allied to Cidaris hispinosa. On the peculiar structure of the anal
system of Cidaris hisp>inosa, radically difierent from that of other Cidaridse, I had based
the genus Stephanocidaris (BuU. Mus. Comp. ZooL, vol. i.). I have also examined the
tests of Stephanocidatis hispinosa and of Phyllacanthus annxdifera in our collections
(Mus. Comp. Zool.), and find that in both these species we have existing on the same tests
tubercles more or less distinctly crenulated as well as smooth tubercles. In Stej^hano-
cidaris the crenulations were limited to those tubercles placed immediately round the
abactinal system, which, as is well known, are not the largest nor most characteristic
tubercles in the Cidaridae, and do not always carry spines identical in appearance with
the other primary spines of the test. In Phyllacanthus annidifera, on the contrary, the
crenulated tubercles were found irregularly scattered on the coronal plates. I may add
that I was much surprised to find on a specimen of Dorocidaris papillata (hystrix)

(zOOL. CHALL. EXP. — PART IX. — 1881.) I 6

42 THE VOYAGE OF H.M.S. CHALLENGER.

from the Mediterranean, one primary tubercle ou the equatorial part of the test showing
most distinct traces of crenulation.

I have not found crenulated tubercles in any of the species of Goniocidaris I
have thus far examined {Goniocidaris tubaria, Goniocidaris geranioides). In all the
specimens of Dorocidaris I have thus far examined, the -tubercles were all smooth, with
the exception of an occasional pit, which may prove to be the first indication of a more
definite crenulation in the genus. Even in Dorocidaris blakii (Alexander Agassiz, Bull.
Mus. Comp. Zoo]., 1879) no trace of crenulation has been found in any of the specimens
I have examined. Yet this species, from its remarkable radioles alone, would, if found
fossil, have been referred to Rhahdocidaris without any hesitation by every paleeon-
tologist.

I hope, in the examination of the series of Dorocidaris blakii for the final Report of
the Echinids of the " Blake," to have some additional data on this subject, and to enter
again into an examination of the crenulation of the tubercles in the other families of
recent Echinids in which this character is found, more particularly in the Clypeastroids
and Spatangoids, where the crenulation of the primary tubercles is not uncommon in
many species on some part of the test.

The mammary boss is prominent and perforate. There are not in either of the
denuded specimens of this collection any traces of the muscular impressions ou the areola
on which Desor characterised the genus, and which, as Thomson has already shown, is not
an important feature, being frequently greatly developed in other genera, and depending
on the strength of the muscular attachment of the spines. This species and Porocidaris
purpiirata difier in the position of the genital openings. In the present species, in a
specimen measuring 41 mm. in diameter, the female openings are large (PI. III. fig. 2),
circular, and entirely within the genital plates ; and do not extend, as in Porocidaris
purpurata, into the interambulacral area. The large female genital openings probably
indicate that Porocidaris elegans, like Goniocidaris canaliculata, is viviparous.

Thomson has described in an alcoholic specimen of Porocidaris pur^mrata the large
eggs and ovaries, which resemble those of other viviparous species of Cidaris. The
position of the genital openings in some of the Cidaridae (as in Goniocidaris) encroaching
upon the interambulacral system is interesting, as indicating the first trace of the separa-
tion of the genital openings from the apical system. Such an absence of connection, or
so indifferent a connection between the so-called genital plates and the apical system,
occurs in many groups of Echinids. This connection becomes entirely severed in some
species of Clypeastroids. The ocular plates are broader than in Porocidaris purpurata.
In a younger specimen measuring 28 mm. in diameter (PI. III. fig. 4) the genital
openings were quite small. This specimen may be only a male, or the genital openings
may be developed to their full size much later. It is more probable, however, that this
example is a young male.

REPORT ON THE ECHINOIDEA. 43

The primary interatabulacral radicles (PI. III. fig. 7) of this species are in the
specimens collected more uniform in shape than those of Porocidaris j^urj^urata .
They are often three times the diameter of the test, cylindrical, slightly tapering, finely
striated longitudinally, with minute sharp serrations. They diff'er from those of Poro-
cidaris purpurata in having a short collar above the milled ring, while in the primary
spines of Porocidaris purpurata the collar is frequently half the length of the spine and
of a dark colour, in striking contrast to the white shafts. On the actinal side round the
actinostome some of the primary interambulacral spines assume the curved spatula shape
with serrated edges so characteristic of the spines of this genus (PI. III. fig. 8a, h), the
actinal opening is small (PI. III. fig. 3), and the whole surface is covered by the long im-
bricating plates of the ambulacral system ; the nature of these plates as modified ambu-
lacral plates is readily traced in one of the specimens examined, where the ambulacral
plates of the test proper are still partly soldered to the coronal plates. The interambu-
lacral plates, however, appear independently as small plates, and are not ordinary in-
terambulacral plates modified, as is well shown by Loven (Etudes sur les Echinoidees) in
his drawing (woodcut, page 29).

The pedicellarise characteristic of this species are figured on Plate III. figs. 10, 11, 12.
In Porocidaris elegans the large-headed short-stemmed pedicellarise, \ery similar to
those of Dorocidaris, vary greatly in shape (PI. XLIV. figs. 6, 7, 11), and the short-
stemmed globular abactinal pedicellariae (PI. XLIV. fig. 10) are somewhat pyramidal and
elongate.

Station 214. February 10, 1875. Lat. 4° 33' N., long. 127° 6' E. ; 500 fathoms ;
bottom temperature, 5 '3° C. ; globigerina ooze.

Station 164a. June 13, 1874. Lat. 34° 13' S., long. 151° 38' E. ; 410 fathoms;
grey ooze.

Goniocidaris.
Gonioddaris, Des., 1846, in Agass. et Des., Cat. Eais.

Goniocidaris canalicidata (Pis. II., XLIV. figs. 1-3).

Temnoeidaris canaliadata, A, Agassiz, 1863, BuU. Mus. Comp. Zool., vol. i.
Goniocidaris canaliculata, A. Agassiz, 1872, Revis. Ech., part 1.

In the Revision of the Echini, I referred Temnoeidaris canaliculata (A. Agassiz, Bull.
Mus. Comp. Zool., 1863, vol. i. p. 18) to Goniocidaris. The material then at my com-
mand was not very ample, and the specimens collected by the Challenger at Kerguelen
Island, in the Straits of Magellan, and at the Falkland Islands, have brought out some
interesting points, showing that the deep vertical sutural line (PI. II. fig. 4), on
account of which this species was removed to Goniocidaris, is frequently totally
obliterated (PI. II. fig. 5) by secondary granulation and by tubercles, both in the

44 THE VOYAGE OF H.M.S. CH^VLLENGER.

median ambulacral and interambulacral spaces, leaving only here and there traces of its
former existence. The variation in the length of the spines is also very marked, so that
many specimens would at first sight readily pass as Cidaris 2}(i'2^ii^((ta (PL II. fig. 1).
It was one of these varieties of Goniocidaris canaliculata which Thomson described
and figured as Cidaris nutrix in his Voyage of the Challenger, vol. ii. pp. 226, 227
(fig. 42). There is nothing constant in the connection of these features. We find
specimens with long spines and deep median vertical furrows, and the reverse,

Studer (Berlin Akad. Monatsb., 1876, p. 455) has noticed from Kerguelen Island
and the coast of Patagonia two species of Goniocidaris {Goniocidaris menibranipora
and Goniocidaris vivi^xira), both of which I am inclined to refer to Goniocidaris
canaliculata. The existence of large genital openings covered by a thin membrane
{Goniocidaris memhranipora) to facilitate the passage of the viviparous young, had not
been noticed in the older descriptions, and the differences upon which he separates
Goniocidaris vivipara from Goniocidaris memhranipora do not seem to be constant,
judging at least from the great variation in the size and position of the genital and
ocular plates in the sjoecimens collected by the Challenger, and from the great variation
in the length as well as ornamentation of the radioles. Thomson^ and Studer^
published about the same time notices that Goniocidaris was viviparous, and that the
young were carried upon the abactinal system, protected by the upper spines of the test,
until their full development had taken place.

On Plate II. are figured three of the most characteristic types of Goniocidaris
canaliculata, one (fig. 1) with long slender cylindrical spines, some of them twice the
diameter of the test. Fig. 2 represents from the abactinal side a specimen with compara-
tively short radioles, scarcely two-thirds the diameter of the test in length, but the
ornamentation of the spines is similar to tliat of the long cylindrical spines of fig. 1.
Both these specimens were covered with comparatively coarse papillae. In fig. 3 is
represented a specimen with much finer and more numerous papillas, and also slender
but short spines. Among the many specimens collected by the Challenger, all possible
combinations of fine and coarse papillae, with slender, long, or short, or with stout and
short radioles, were observed, showing, as in other species of the family, a most
extensive degree of variation, while in other Cidaridse with extremely variable spines the
characteristic features of the test are tolerably constant. In this species the variation is
not limited to the primaiy radioles and paj^iUae, but extends also to the ornamentation
of the test. This shows, as I have mentioned above, a median suture in all possible stages
intermediate between a broad suture (PI. III. fig. 4), or a deep sharply cut groove
(PI. III. fig. 6), and an almost indistinct bare space (PL III. fig. 5).

An interesting account of the mode of carrying the young in this species is given by
Thomson (Voyage of the Challenger, vol. ii. p. 228). " The eggs, after escaping from

' Joiirii. Linn. Soc, vol. xiii., June 1876. Berlin Akad. Monatsb,, July 1876.

REPORT ON THE ECHINOIDEA. 45

the ovary, are passed along on the surface of the test towards the mouth, and the
smaller slightly spathulate primary spines, which are articulated to about the first three
rows of tubercles round the peristome, are bent inwards over the mouth, so as to form
a kind of open tent, in which the young are developed directly from the egg without
undergoing any metamorphosis, until they have attained a diameter of about 2 '5 mm. ;
they are then entirely covered with plates, and are provided with spines exceeding in
length the diameter of the test. Even before they have attained this size and develop-
ment, the more mature or more active of a brood may be seen straying away beyond the
limits of the ' nursery,' and creeping with the aid of their first few pau's of tentacular
feet out upon the long spines of their mother ; I have frequently watched them return
again after a short ramble into the ' marsupium.' "

The specimen (PL II. fig. 2) shows the manner in which they are held in a sort of
marsupium by the folding of the abactinal spines over the young crowded upon the
abactiual system. This, as is shown in Plate II. fig. 7, cuts deeply into the median
ambulacral and interambulacural spaces. The female genital openhigs are notched in the
very edge of the genital plates.

From among the many young collected by the Challenger, I was able to obtain two
most interesting stages of growth of this genus. Plate II. figs. 9, 10, represent from the
actinal and abactinal sides a young Goniocidaris, in which we find as yet no separation
of ambulacral or interambulacral plates. These areas are, however, most distinctly
marked by the presence of large primaiy tubercles and spines in the latter area, and by
the presence of three pairs of small tentacles in each ambulacral zone, surmounted by a
huge odd terminal tentacle (PI. II. figs. 9, 10, 18). The ambulacral tentacles are
separated by a vertical row of tubercles carrying small primary spines, but the test is
not subdivided into zones by plates ; it is as yet composed only of more or less close
reticulation and irregularly shaped plates, thickly covered with pigment spots. I
attempted in vain to find the eye at the base of this huge odd terminal tentacle, the
homologue of course of the odd terminal tentacle of the ray of the starfish, in which we
can so easily trace the eye in very early stages. The mass of pigment covering the
test, spines, and tentacles, made it impossible to observe the eye if it does exist. I
have also failed to see the eye in the young Echinids of other genera' which I had
occasion to examine, many of which were less advanced than the young of Goniocidaris
here described. This stage is interesting as showing perhaps more plainly than in any
other young Echinids I have seen, that the abactinal system is developed simultaneously
with the coronal plates from the primary reticulation of the test, whUe the actinal
system on the contrary is from the earliest stages separated as such from the coronal
plates. In a view from the actinal side (PL II. fig. 9) the ten buccal tentacles are weU

1 See A. Agassiz, Jlem. Am. Acad., vol. ix, 1864, Embryology of Echinodenus ; and A. Agassiz, Kiubryoluj^y of the
Starfish, 1864, in Agassiz's Cont. Nat. Hist. U. S., voL v. ; also Menioii's Mus. Comp. Zool., vol. v.. No. 1, 1877.

46 THE VOYAGE OF H.M.S. CHALLENGER.

seen. The anus already opens in the centre of the abactinal part of the test (PL II.
fig. 10). The spines at this stage (PI. II. figs. 9, 10) have already assumed much more
the general appearance of those of the adult than is usually the case among young
Echinids. In the next stage (PL II. fig. 12) the tentacles are contracted, the spines are
much longer, the tubercles well formed, the papillae commence to be formed on the
abactinal system, and the plates composing the ambulacral and interambulacral areas can
readily be distinguished (PL II. fig. 8). Judging from the proportion of the spines to
the test, this is probably the young of a long-spined specimen. One of the short-
stemmed pedicellarife of the abactinal region of the test (from a full grown specimen)
is figured on Plate II. fig. 15, one from the test (fig. 17), and the same kind in difierent
stages of development (fig. 16).

In Goniocidaris canaliculata the long-stemmed ambulacral pedicellarise (PL XLIV.
fig. 1) have an elongated triangular head, supported upon a comparatively stout rod
(PL XLIV. fig. 3).

Station 149, Royal Sound, Kerguelen. January 17, 1874. Lat. 49" 40' S., long.
70° 20' E. ; 25 fathoms.

BaLfour Bay, Kerguelen ; 20 to 60 fathoms.

Station 315. January 26, 1876. Lat. 51° 40' S., long. 57° 50' W. ; 5 to 12
fathoms ; sand and gravel.

Kerguelen Island. January 19, 1874.

Station 151. February 7, 1874. Ofi" Heard Island; 75 fathoms ; mud.

Station 313. January 20, 1876. Lat. 52° 20' S., long. 68° 0' W. ; 55 fathoms;
bottom temperature, 8 "8° C. ; sand.

Ofi" Christmas Harbour, Kerguelen Island ; 120 fathoms.

Stanley, Falkland Islands; 5 to 10 fathoms.

Station 150. February 2, 1874. Lat. 52° 4' S., long. 71° 22' E. ; 150 fathoms;
Ijottom temperature, 1"8° C. ; rock.

Station 153. February 14, 1874. Lat. 65° 42' S., long. 79° 49' E. ; 1675
fathoms ; mud.

Station 156. February 26, 1874. Lat. 62° 26' S., long. 95° 44' E. ; 1975
fathoms ; diatom ooze.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. ; 1600 fathoms ;
bottom temperature, 0'8° C. ; globigerina ooze.

*Goniocidaris florigera (PL I. figs. 7-20 ; PL XXXVIII. fig. 11; PL XLII. figs.
2, 3 ; PL XLIV. figs. 4, 5).

Goniocidaris florigera, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 198.

In no species of the family (excepting Dorocidaris hlahii) do I know so great a
difi'erence between the primary radicles of diS"erent parts of the test. In one of the

REPORT ON THE ECHINOIDEA. 47

specimens the most prominent primary spines are cylindrical, slightly curved, some of
them more than twice the diameter of the test in length (PI. I. fig. 12), tapering so
little that at the extremity, which is probably broken or worn, they are nearly of the
same diameter as at base. These long spines recall the spines of Salenia hastigera, and
remind us among the fossil Cidaridse very strongly of the cylindrical spiny radioles of
some species of Rhabdocidaris. These largest radioles are smooth, covered irregularly by
sharp spines, equalling its diameter in length near the base of the radioles (PI. I. fig. 1 8).
These spines are large and few in number near the base, becoming more numerous and
smaller towards the extremity of the radiole. Near the ambitus the radioles are .shorter
and more slender ; the serrations, closely crowded, sometimes form an irregular fluting
(PI. I. fig. 19), or they resemble the long curved cylinclrical primary radioles. Immedi-
ately around the abactinal area the primary spines, while similar in structure at the base
to the more prominent spines, are remarkable for the immense dilatations of the tip
(PI. I. fig. 12), the points of which frequently ramify, forming a flattened cup equalling
in diameter one-third the diameter of the test (PI. I. figs. 15, 16).

In Goniocidaris tubaria and Goniocidaris gemnioides we find similar cupuliform
spines near the abactinal region, but the spreading of the tip of the radioles is not
so great in proportion to the diameter of the test. The papUlae covering the abactinal
area are small, with the exception of a few immediately surrounding the anal open-
ing (PI. I. fig. 12o); those at the base of the primary spines in the interambulacral
areas are short and broad, in striking contrast to the remarkably slender and delicate
papillae of the ambulacral area. There is a marked contrast in the curve of the actinal
and abactinal portions of the test ; the former is much more convex than is usual
among Cidaridae, the outline of the test when seen in profile resembling somewhat
the shape of the test of Echinostrephus. In another specimen (PI. I. fig. 7) there
are on the actinal side only a few of the cylindrical spines such as were characteristic
of the first specimen (PI. I. fig. 12), the other primary interambulacral radioles being
very uniform in character, slightly swollen above the coUar, gradually tapering to
a point, with large spines scattered over the whole surface of the shaft (PI. I.
figs. 8, 9), There are no cupuliform spines near the abactinal system. The radioles are
somewhat longer than the diameter of the test. The ornamentation of the test is limited
in this species to small deep pits at the angles of the plates in the median interambulacral
lines (PI. I. figs. 13, 14). The greater part of the coronal vertical sutures are edged by
irregular minute ridges, showing in the interval left between them the deep narrow sutural
line near the ambitus. Near the abactinal pole the vertical suture is reduced to a sharp
line. The secondary tubercles of the scrobicular area are in contact along the horizontal
lines of sutures (PL I. figs. 13, 14). Coronal plates high, mammary boss small, scrobi-
cular area deep.

Along the horizontal suture, at the junction of the coronal plates with the poriferous

i8 THE VOYAGE OF H.M.S. CHALLENGER.

zone, a small ill-defined pit exists. The poriferous zone is narrow, the paii-s of pores
separated by high ridges are somewhat wider in the central part. The median ambulacral
area is wider than the poriferous zone. The ambulacral plates are separated from the
poriferous zone by a vertical row of distinct secondary granules. The lower part of the
ambulacral plates is occupied by minute granides, leaving distinct bare spaces forming-
small rectangular pits, which alternate for the whole height of the ambiilacral area (PI. I.
fig. 13). The larger granules carry short, slender, sharp papillae, while the miliary granules
carry diminutive papillje scarcely equal in length to the height of the ambulacral
plates. The ocular plates are heart shaped. The genital plates are heptagonal, separated
by large pointed plates from the anal system, which extends to the ocular plates. The
genital openings are large, situated nearer the centre of the plates than the edge. The
anal system is covered by a single row of ten larger plates adjoining the genital plates,
with smaller irregularly-shaped plates in the centre. The whole abactinal system is
closely covered with indistinct tubercles carrying short sharp jjapillae, somewhat largest
around the anal opening. The outer part of the coronal plates not occupied by the
scrobicular tubercles is closely packed with minute granules carrying diminutive papillse
similar to those of the median ambulacral space. The colour of the spines of alcoholic
specimens is white; the papillae round the base of the primaries are light reddish-yellow.
This species is remarkable for its small actinal opening.

In a specimen measuring 27 mm. in height, in which there are seven primary
tubercles, the diameter of the test is 26 mm. ; the diameter of the actinal system,
1 1 mm. ; and that of the abactinal system, 1 3 mm. The length of the longest curved
primary spine is 56 mm.

The ornamentation of the sutures of this species, extending over the greater part of
the coronal plates, shows the affinities of Goniocidaris with Temnocidaris of Cotteau (not
A. Agassiz); see Pal. Frangaise, PL 1085-1087 (bis).

The short-stemmed globular-headed interambulacral pedicellarise of Goniocidaris

Jlorigera (PI. XLII. fig. 3) are remarkable for the great size of the basal part of the

head and the small open foramina left between the terminal prongs of the head.

These are larger than we usually find them in the corresponding pedicellarise of other

Cidaridse.

The shape of the long-stemmed narrow-headed ambulacral pedicellarise is shown
on Plate XLII. fig 2. On the test the globular-headed short-stemmed pedicellarise
are more elongate (PL XLIV. fig. 5), and the terminal prong of the valves is
stouter.

Station 192. September 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129 fathoms ;
mud. Ki Islands.

Station 204. November 2, 1874. Lat. 12° 43' N., long. 122° 10' E. ; 100 fathoms
and 115 fathoms; mud.

EEPORT ON THE ECHINOIDEA. 49

Goniocidaris tuharia (PL XL. figs. 1-25).

Cidarites tuharia, Lamk., 1816, Aniin. sans Vert.
Goniocidaris tuharia,^ Liitk., 18G1, Bid. til Kund. om Ech.

A large number of specimens of all sizes were collected oflf Moncoeur Island, Bass
Straits. This has enabled me to examine the range of variation of the primary radioles of
this species ; the principal ones are figured on Plate XL. figs. 1-25.

From the sections of spines of Cidaris it is evident that the variations of the
shape and of the size of the appendages is entirely due to the greater or less
development of parts of the sheath of the radioles characteristic of the Cidaridge.
The differences in the shape of the radioles noticed on the same specimens of genera of
Cidaris, oi Doivcidaris, oi Porocidaris, of Phyllacanthus, of Goniocidaris, &c., in fact,
of all the recent genera of Cidaridse, show the utter impossibility of distinguishing the
species of this family by any differences in the shape of the primary radioles. The
secondary ornamentation, such as the granules, their size and arrangement, is a far better
guide, but the effect of this is apt to be greatly modified when we find it on a deeply
fluted radiole, a flat fan-shaped or a highly serrated piimary spine. The greatest caution
must be exercised in using even this character, and the determination of species of
Cidaris by palaeontologists from fragments of radioles, or even from primary radioles,
appears to be, judging from our knowledge of the recent types, of but little value. With
the exception of the club-shaped radioles, such as Cidaris dorsata (Braun), Cidaris rcemeri
(Wissm), from the Trias, Cidaris glandi/era (Goldf.) and the like, from the Jura, and
Cidaris clavigera (Keen) from the Chalk, there are none of the many differently shaped
radioles, probably belonging to Cidaridse of the Jura or of the Chalk and Tertiary, which
are not represented in species living in the seas of the present epoch. So that, as far as
the Cidaridse are concerned, we have, with the exceptions mentioned al)ove which have
disappeared, and wath the exception of Diplocidaris and Tetracidaris, the same generic
types now living which characterised first the Jurassic, then the Cretaceous, and finally
the Tertiary seas.

From the fact that the Cidaridse like other Echinids, in fact, like all Echinoderms,
are gregarious, we ought to be exceedingly cautious in characterising a foiTaation or a
bed from the fossil Echinids of any special locahty. No better instance of the negative
character of such evidence could be given than the hauls made at different depths in
regions not very remote geographically. The experience of all deep-sea dredging,
and, in fact, of dredging even at moderate depths, seems conclusive. A few instances
will suffice.

Thomson often brought up in the "Porcupme" immense numbers o{ Echinus norvegicus,
Cidaris papillata, Spatangus raschi, and Brissopsis lyrifera.

1 111 the Revision of the Echini, I did not refer this to Liitken as I should have done, see Eevis. Echini, pp. 77,
131, 213, 397.

(ZOOL. CHALL. EXP. — PART IX. — 1881.) I 7

50 THE VOYAGE OF H.M.S. CHALLENGER.

In the Challenger the different species of Pourtalesise, of Echinothurise, of Hemi-
aster, of Schizaster, of Goniocickuis, of Cidaris, came up in numbers from certain
localities.

My o-wTi experience has been identical, not only while collecting near the shores the
masses of Strongylocentrotus drobachiensis, of Arhacia, of EcJiinarachnius, of Mellita, of
Clypeaster, of Encope, of Rhynchopygus, of Moira, and in deep waters, oi Asthenosonui,
Scdenia, Aspidodiadema, Paleopneustes, and more particularly the species of Cidaris,
which, certainly if we had characterised our beds from such species as Cidaris tribuloides,
Dorocidaiis ■papillata, Dorocidaris hlakii, or Porocidaris, would give to a bed a very
different facies based upon very local distribution and occurrence in great numbers at
different localities. The same is true of the dredgings of Starfishes, Ophiurans, and
Holothurians.

I have figured on Plate. XL. figs. 1-25, the differently shaped spines which occur on
specimens of G. tuharia. They have been selected to show the modifications of a simple
tapering spine (PI. XL. fig. 19), with slight nodes so as to form on the one side the spiny,
slightly cupuliform primary spines (PL XL. fig. 1), and on the other the short, cupuliform
spines (PL XL. fig. 1 8) characteristic of the abactinal part of the test, and the elongate,
slightly spinose, and but little cupuliform spines (PL XL. fig. 16) which give the extremes
of the forms of spines found in Goniocidaris tuharia. At the same time, the inter-
mediate forms showing the passage between these three extreme types give an excellent
idea of the great variation of the radioles in the genus Goniocidaris, and of the impossi-
bility of drawing reliable specific characters from the shape of the radioles alone, even when
taking carefully into account the ornamentation of the spines themselves, the nature of
which is frequently obliterated by the important changes in outline which characterise the
primary spines. This of course applies not only to this genus but in general also to
the species of the family Cidaridfe.

Station 161. April 1, 1874. Off entrance to Port Philip; 38 fathoms; sand.

Station 162. April 2, 1874. Off East Moncoeur Island, Bass Straits; 38 to 40
fathoms ; sand.

Salenid^.

Sub-family Salenidce, Agassiz, 1838, Moii. Ech. Sal6nies {emend.).

Salenia.

Scdenia, Gray, 1825, Ann. PhU.

Tertiary Salenice are now known from France and from Australia, and also from
Sindh.^

' Cotteflu, Rev. and Mag. Zool., JIai. 1860.

REPORT ON THE ECHINOIDEA. 51

The Salenia tertiaria of Tate ^ is carefully described by Duncan.^ He mentions the
numerous ambulacral tubercles in four vertical rows somewhat as in Salenia hastigera,
and more especially the presence of but a single pair of pores to each tubercle as in the
recent SalenidsB, while this is not the case in the older fossil Salenid« ; and it is somewhat
remarkable to find this structural feature in the Tertiary species, for, from what we know
of the mode of development of the ambulacral regions in other Echinids, the character
just alluded to in the older Salenidse is not an embryonic one, as the crowding of the
poriferous zone is, as far as we know, now prominently developed only in the older stages
of growth of the Desmosticha. The Hemicidaris character of the existence of a few
large primary tubercles near the actinostome is quite striking in Salenia varispina, and
much less so, though it exists, in Salenia hastigera.

Duncan has described in the Annals and Magazine, vol. xx. p. 70, the spha^ridia of a
species of Salenia, dredged by the Challenger, which he names Salenia prof undi ; and on the
strength of the presence of sphaeridia and their absence in the Cidaridae, as well as the
character of the buccal membrane, he retains the Salenidee as an independent family, and
as more closely allied to the Echinidae proper than the Cidaridse, with which I had
associated them more closely than other authors had done. I, however, hardly think that
the single additional structural point he mentions (the existence of sphseridia) is a
sufficient ground for taking what I consider a retrograde step in our ideas of the affinities
of the Saleuidse.

An unfortunate misprint occurs in my description (Eevis. Echini) of Salenia
varispina. While speaking of the imbricating buccal membrane, it reads " much as in
Echinocidaris ;" it should have been " as in Trigonocidaris." I may be allowed to state
that I was fuUy aware that Echinocidaris is identical with Arhacia, as Dr Duncan states
(see Ann. and Mag. Nat. Hist., 1877, vol. xx. p. 248), and also that the imbricated plates
of Salenia varispina show on my figures (Eevis. Echini, pi. iii.) ; and as I have shown, this
is an important difierence between Salenia hastigera and Salenia varisjnna.

As Duncan justly remarks with regard to the number of the primary tubercles, their
number cannot be limited to ten as I had stated it in the Revision; but, on the other hand, his
statement that the number of primary tubercles is indicated long before the test assumes its
largest size, will have to be greatly modified judging from the young SalenitB dredged l^y the
" Blake." To this point, however, and to the relationship of Salenia varispina to Peltastes or
Hyposalenia, I shall return in the final Report of the Blake Echinoidea, when giving an
account of the changes undergone by Salenia during growth, which afiects materially the
position of the anal system. I should say, however, that the single specimen of Salenia on
which my original description in the Revision was based appears to be somewhat anomalous
in the size of the anal system, and its degree of encroachment on the genital plates. I do

1 Tate, Quart. .Jour. Geol. Soc. London, vol. xxxiii. p. 256, fig. 2, p. 257.
- Duncan, Ami. and Mag. 1878, vol. ii. p. 61.

52 THE VOYAGE OF H.M.S. CHALLENGER.

not wisli to maintaiu untenable views, and not to seem to yield to apparently overwhelming
evidence as to the way to use the position of the madreporic body to ascertain the axis of
the body. It is not my intention to argue the question anew, but I must reiterate that no
evidence has as yet been advanced disproving the position I start with, that the madi'cporic
body is placed at the suture of the embryo Echinid formed by the junction of the ends of
the open spu-al forming the young Sea-urchin in the Pluteus, and no amount of observation
on the abactinal system of young forms after they have resorbed the Pluteus, or in the
adult stages, will throw any light on that point. I cannot see the force of the distinction
made by Dr Duncan between embryonic spines and papillae, which he says cover the apical
disc, because they are not placed on tubercles. No young spine of any Sea-urchin is
articulated when it first appears, nor is it placed upon a tubercle, and I merely intended
to denote the fact that these appendages were embryonic spines, from their greater
similarity to young spines, and remained so ; and it does not seem to make a material
difference in the description if we call them papillae.

From the careful description of Duncan's Salenia profundi, which is the name
he gives to his species, it is evident that it is more closely allied to Salenia goesiana,
of which it may be the adult, and that it differs very considerably from Salenia
varispina (A. Agassiz); but not having seen Dr Duncan's specimen I am unable to
associate it with Salenia hastigera, the spines of which differ radically from his. All
the specimens (five) collected by the Challenger in the Bay of Biscay and ofl' the coast
of Portugal belonged to the species which I have here called Salenia hastigera, and
have figured on Plate IV. of the Challenger Echinoidea. As these specimens were
among the first returned to Sir Wy\'ille Thomson before Dr Duncan's description
appeared, I am unable to examine them again and compare them with Dr Duncan's
description. Thomson's figures, on pp. 145 and 146, Voyage of the Challenger, Atlantic,
vol. i., evidently represent Salenia hastigera. This is not the only instance of
a Pacific species being found off Portugal. The same is the case with Aspidodiadema
tonsum.

With regard to the crenulation of the primary tubercles, the primary ambulacral
tubercles near the astinostome are certainly, as I have stated, crenulated like the primary
tubercles of the interambulacral areas ; but the secondary ambulacral tubercles, which
continue the line of the larger primaries to the abactinal system, are not. My description
was not sufficiently complete, and I should perhaps have stated that the smaller
ambulacral tubercles are not crenulated. I did not attach special importance to this
character, beyond stating the fact of its existence, on account of the great difference there
is known to exist in other Echinidae with reference to this very point. I must also add
here that the lai'ge primary tubercles near the actinostome in Salenia hastigera are
also distinctly crenulated, but the smaller ones are not. The structure of the spines
most emphatically associates the Salenidae with the Cidaridae, as a cross section

REPORT ON THE ECHINOIDEA. 53

will show at once ; the verticillation also of Salenia hastigera is not produced as in the
Diadematidse, but by the regular arrangement of the processes of the outer sheath as in
the Cidaridse.

There still remains also tlie other important feature, thus far found only among the
Cidaridse, the peculiar nature of the secondary spines forming, as in the Cidaridse proper,
the rows of papillae regularly arranged in the intertubercular spaces of both areas, and
forming also the secondary spines. The jaws and teeth of Salenia do not give as
definite information regarding the affinities of the genus. The teeth of Salenia hastigera
are, like those of the Echinidge proper, keeled, though with a broad flat keel, while the
compact nature of the pyramid with its small apical foramen, and the proportionally
large size of the tooth, brings them into close proximity to the Cidarides, between them
and the Axbaciadae; nor is the presence of gills and slight gill cuts an objection to their
association with the Cidaridse.

I have already called attention, in the Ee-\asion, pp. 645 and 694, to the existence
of openings for the passage of giUs, and theii- protrusion through these openings
when alive, in our Florida species, although Mllller denies their existence. Mr Charles
Stuart (Trans. Lin. Soc, Dec. 1877) has given excellent figures of organs which are
undoubtedly gills placed within the imbricating membrane, but has not traced their
extension outwards. Whether it is these organs (gills) which find their way through
the cuts or not in our Florida species I am unable to state, and a renewed examin-
ation of living specimens will be necessary before we can settle this interesting
question.

I am not the only writer on Echinids who has associated more closely than has usually
hitherto been done the Salenidas and Cidaridse. De Loriol had previously, in the Echinol.
helv., taken very much the same ground, though he subsequently modified his view, and
now inclines to unite the Salenidse to the Glyphostomes as a tribe, and not to the Cidaridse,
which he contrasts to the other regular Echinids as Holostomes. I do not feel that this
character taken by De Loriol can be employed to denote primary subdivisions among the
Echinoidea, for among the Diadematidaj and Echinothuridse we at once find forms,
otherwise closely allied, which differ radically in this one point considered so essential by
De Loriol, and as fast as new material accumulates both among living and fossil Cidaridse
it little by little shows the insufficiency of characters on which we have been accustomed
to contrast so strongly the Cidaridse with the other famihes of the regular Echinids. I
need only mention here the enormous difference made in our estimate of the value of the
famdy character of the Cidaridse by the discovery of such genera as Diplocidaris and
Tetracidaris.

54 THE VOYAGE OF H.M.S. CHALLENGER.

''Salenia hastigera (PI. IV. figs. 3-17; PI. XXXVIII. fig. 10).

Salenin liasligera, A. Agassiz, 1879, Proc. Am. Acad., vol xiv. p. 198.

This species difi'ers from Salenia varispina, A. Agassiz (Revis. Echini, pi. iii. figs.
8-14), iu the closer and uniform granulation covering the abactinal system, and the more
central position of the genital openings (PL IV. fig. 10). The primary spines are
comparatively much longer, some of them equalling four times the diameter of the test
(PI. IV. fig. 3). They are more or less cylindrical, varying but little in shape. Though
they are usually straight, sometimes considerably curved, they taper very gradually and
are covered from the base to the tip with numerous small sharp spines closely arranged
in regular rings round the shaft (PL IV. fig. 17). On the longest radicles the smaU
spines are frequently worn ofi", the extremity of the shaft showing only a delicate longi-
tudinal striation. The primary radioles of the actinal surface are similar to those of
Salenia varispina, but, although flattened and with few sharp spines along the margin,
are quite slender. The spines of the median interambulacral space and of the ambulacral
region are short club-shaped but less variable in outline, and more slender, especially
towards the abactinal region, than the corresponding spines of Salenia varispina. The
apical system of Salenia hastigera conforms entirely in the arrangement of its plates with
that of the normal Salenia, the anal system being surrounded by two of the genital plates
and by the subanal plate.

In young specimens of Salenia varispina the anal system encroaches only upon one
of the genital plates, and subsequently in older specimens the position of the anal system
does not difi'er in the two species. In none of the specimens of Salenia hastigera
examined, even the smallest, do we find any indications of the deep pits along the Lines
of sutures of the plates of the abactinal system, such as are so well-marked in young
specimens of Salenia varispina. The madreporic body is not more prominent than in
the other species of the genus; it consists of only four to six small openings adjoining
one of the genital openings (PL IV. fig. 16). The ocular plates are proportionally longer
and narrower than in Salenia varispina. The anal system is covered by a number of
plates irregularly arranged in two to three concentric rows round the anal opening ; they
carry small papillEe. In a younger specimen the plates immediately round the anal
opening (PL IV. fig. 12) are triangular, much as the plates covering the whole anal
system of Salenia varisp>ina. With this exception and the comparatively larger size of
the ten buccal plates of the actinal membrane, the smaller specimens of Salenia hastigera
(PL IV. figs. 12, 13) already possessed the characteristic features of the larger specimens.
The number of primary tubercles in the interamljulacral area is smaller in this species
(PL IV. fig. 15) than in Salenia varispina (PL IV. fig. 1), in the proportion of six to
eight ; and in the ambulacral area at the actinostome we find only two or three large
tubercles (PL IV. fig. 14), while in Salenia varisioina (PL IV. fig. 2) they form, as in

EEPORT ON THE ECHINOIDEA. 56

Hemicidaris, a row of tubercles regularly decreasing in size towards the abactinal
system. The secondaries surrounding the primaries are also more numerous and
more closely crowded in Salenia vanspina than in Salenia hastigera. I dredged
in the "Blake," during the season of 1878-9, an extensive series of young Salenice
{Salenia varispina), which will be fully described in my final Report of the Blake
Echini.

Station 106. August 25, 1873. Lat. 1° 47' N, long. 24° 26' W; 1850 fathoms;
bottom temperature 1"8° C. ; globigerina ooze.

Station 195. October 3, 1874. Lat, 4° 21' S., long. 129" 7' E. ; 1425 fathoms;
bottom temperature, 3"0° C. ; grey ooze.

Station 170. July 14, 1874. Lat. 29° 45' S., long. 178° 11' W. ; 630 fathoms;
bottom temperature, 4"0° C. ; rocks.

Station 171. July 15, 1874. Lat. 28° 33' S., long. 177° 50' W. ; 600 fathoms;
bottom temperature, 4'0° C. ; rocks.

Station 335. March 16, 1876. Lat. 32° 24' S., long. 13° 5' W. ; 1425 fathoms;
bottom temperature, 2 '3° C. ; globigerina ooze.

Oflf Cebu, 100 fathoms.

Off Macio, 1700 fathoms. September 11, 1878.

Bay of Biscay and Coast of Portugal, January and December 1872 and 1873.

Salenia varisxnna (PI. IV. figs. 1, 2).

Salenocidaris varispina, A. Agassiz, 1869, Bull. Mus. Comp. Zool., vol. i.
Salenia varispina, A. Agassiz, 1872, Eevis. Ecb., part 1, p. 155.

A number of specimens of this species were dredged by the Challenger, and I have
been able to supplement in many points the first description based upon a single
specimen dredged by M. Pourtalfes. These additional characters I have called attention
to in the comparative description of the preceding species, Salenia hastigera with Salenia
vanspina. Salenia varispina is more closely allied to Salenia gcesiana of Loven, of
which the latter may be only a young stage. The dredgings of the United States Coast
Survey Steamer "Blake" show that this is quite a common species in the Caribbean Sea
to the leeward of the Lesser Antilles.

Station 122. September 10, 1873. Lat. 9° 5' S. to 9° 10' S., long. 34° 49' W. to
34° 53' W. ; 350 fathoms; mud. Ofi" Barra Granda.

Station 24. March 25, 1873. Off" Culebra Island; 390 fathoms; mud.

Station 23. March 15, 1873. Off Sombrero Island; 450 fathoms; globigerina
ooze.

Station 344. April 3, 1876. Off Ascension Island; 420 fathoms; liard gruum].

56

THE VOYAGE OF H.M.S. CHALLENGER.

Station 78. July 10, 1873. Lat. 37° 24' N., long. 25' 13' W. ; 1000 fathoms;
globigerina ooze.

Station 70. June 26, 1873. Lat. 38' 25' N., long. 35' 50' W. ; 1675 fathoms;
globigerina ooze.

Station 73. June 30, 1873. Lat. 38' 30' N., long. 31' 14' W. ; 1000 fathoms;
bottom temperature, 3°7 C ; globigerina ooze.

Aebaciad^.
Family Arbaciadse, Gray, 1855, Proc. Zool. Soc. London.

Arhacia.
Arhacia, Gray, 1835, Proc. ZooL Soc. London.

With the exception of Arbacia nigra, the Challenger collected but few specimens of
the genus Ai^hacia, so that no material sufficient to undertake a renewed critical examin-
ation of the group was obtained. I have already alluded to some of the objections
against the view taken by Troschel ^ of the synonymy of several of the species. The
specimens of Arbacia collected by the Challenger at Valparaiso are undoubtedly the
common Arhacia nigra ; the specimens of Arhacia dufresnii collected at Nightin-
gale Island and other localities may, when compared with the specimens of Arbacia
dufresnii collected in the Straits of Magellan by Dr Cunningham, show how far
Troschel is justified in considering Arbacia alternam as a distinct species from
Arbacia dufresnii.

Dr Studer, in his list of Echinids from Kerguelen Island, also distinguishes this species
from A. dufresnii. Troschel's description is exceedingly minute, but as it is based upon
three specimens (one of which is not normal) these differences may after all be only indi-
vidual/lifierences. I have abeady, in the Eevision of the Echini and the "Hassler" Echini,
called attention to the great variability of the characters of the species of this family
drawn from the test, such as the number of tubercles, both primary, secondary, and
miliary, the ornamentation of the plates of the test, and the outline.

Mr Bell ^ has, in a recent number of the Proceedings of the Zoological Society, called
attention to the variation in the number of anal plates, and to the tendency these plates
show occasionally, in having less than four plates, to retain the conditions of many young
Echinids in their youngest stages of having but a single plate covering the anal system; or,
when having more than four plates, to pass into the normal condition of all other regular
Echinids of having a large number of plates covering the anal system. This variation is,
however, by no means so common as he would have us infer from his statistics. The

1 Wies- Archiv, 1873, Die Familieu Jer Echinocidarideu.

2 F. J. Bell, Note on the Number of Anal Plates in Echinoddaris, Proc. Zool. Soc. London, May 1879.

REPORT ON THE ECHINOIDEA.

57

following species I have examined with reference to this very point, and find the follow-
ing results : —

Number of
specimens
examined.

4

Anal
plates.

5

Anal
plates.

7

Anal
plates.

8

Anal

plates.

13

Anal
plates.

Arhaeia nigra.

Callao,

11

11

...

Talcahuano, Chili, ....

12

11

1

Payta,

9

9

...

Arhaeia spatuligera.

West Coast, South America, .

2

2

...

Arhaeid pustiilosa.

Naples, ......

18

18

...

...

...

Fayal

7

7

...

...

...

Arhacici dufresnii.

Straits of Magellan,

6

5

1

...

...

Eden Harbour, ....

8

8

...

...

Arhaeia stellata.

Payta,

10

10

..

...

Callao, ......

4

2

2

Acapulco, ...

8

6

1

1

Lower Calitornia, ....

7

7

Arhaeia punetwlata.

Newport,

10

7

2

1

...

Beaufort, North CaroUna,

16

IG

...

...

Charleston, South Carolina,

10

10

Florida Reefs, ....

12

12

...

The splitting up of the four anal plates into thirteen columnar plates, as is the case in a
large Arhaeia nigra from Talcahuano, seems due in that case to the increase in growtli of
the anal plates in a confined anal area. All the specimens which have more than four
anal plates are fully grown, and I have not found among the many young of Arhaeia
punctulata I have examined, while working on the chapter on young Echinids for the
Revision of the Echini, a single small specimen with less or more than four anal plates.
The largest of these young specimens measuring not quite 5 mm. in diameter down to
about 1-.5 mm. when the young had just resorbed the Pluteus. As I have shown in the
Revision of the Echini (p. 734, fig. 68), the young Arhaeia has already four anal plates
in the earliest stages thus far observed.

It will be interesting hereafter to observe the growth of the anal plates of such

(ZOOL. CIIALL. EXP. — PART IX. 1881.)

18

58 THE VOYAGE OF H.M.S. CHALLENGER.

genera as Salmacis, Temnopleurus and their allies, especially of such forms as Tngono-
cidaris, where the number of anal plates is usually four, and compare it with the growth
of the anal system of Salenia. I have, fortunately, a number of very young Salenice
dredged in the last " Blake " expedition, and hope in my Eeport on the Echini of the
cruise to return to this subject again.

In none of the specimens of Podocidans sctdpta thus far examined (20 + ) have I found
more than four anal plates.

All the specimens of Parasalenia examined (9 + ) have four anal plates. Among the
smaller specimens of CcBlopleurus maillardi collected by the Challenger at Amboyna, of
the thirteen specimens examined all had four anal plates. The same was found to be the
case in the four large specimens from the Straits of Basilan.

Of the " Blake " specimens of Coelopleurus floridaniis I have examined four collected
at Barbados and fifteen at Montserrat ; they all had only four anal plates.

Arbacia dufresnii.

Echinus Dufresnii, BL, 1825, Diet. Sc. Nat. 0.
Arbacia Dufres^iii, Gray, 1835, Proc. Zool. Soc. London.

Nightingale Island ; 100 to 150 fathoms.

Station 308. January 5, 1876. Lat. 50° 10' S., long. 74° 42' W.; 175 fathoms; mud.
Station 304. December 31, 1875. Lat. 46° 53' S., long 75° 11' W.; 45 fathoms;
sand.

Arbacia nigra.

Echinus niger, Molin, 1782, Chili (nou Rumph).

Arbacia nigra, A. Agassiz, 186-3, Bull. Miis. Comi^. ZooL, vol. 1. p. 20.

Gray (1835) did not mention Eckimis nigra in his list of species belonging to
Arbacia, though it was evident he intended to do so.^ In making out my chronological
lists (Revision of the Echini), though the species Echinus nigra does not appear till
1863 under the name of Arbacia 7iigra, it having then been credited to Gray by mistake,
it was accidentally omitted from the list of species, appearing under a new name in
A. Agassiz, 1863, Bull. Mus. Comp. Zool., consec[uently Gray is quoted under Arbaoia
nigra by mistake (Revision of the Echini, p. 401).

Valparaiso shore. November 1875.

Arbacia lyustidosa.

Cidaris pvstulosa, Leske, 1778, Klein Add.

Arbacia ptishdosa, Gray, 1835, Proc. Zool. Soc. London.

St Vincent, Cape Verde Islands.

1 A. Agassiz, 1863, Bull. Mus. Comp. Zool., vol. i.

REPORT ON THE ECEINOIDEA. 59

Podocidaris.
PodoeMaris, A. Agassiz, 1869, Bull. JIus. Coiiip. Zool., vol. i.

* Podocidaris prionigera (PL XXXIV. figs. 14, 15).

Podocidaris prionkiera, A. Aga.?siz, 1879, Proc. Am. Acad., vol. xiv. p. 199.

Although Podocidaris scidpta, A. Agassiz, was not uncommon in the dredgings
of Mr Pourtalfes, and in those of the " Blake," yet the Challenger obtained only two speci-
mens of this species. They both differ from the West Indian species, also collected by the
Challenger at Station 24, in liaving a more conical test ; the primary spines are not so
distinctly limited to the ambitus (PI. XXXIV. fig. 14) as in Podocidaris scidpta, some of
the primary tubercles encroaching irregularly upon the test above the ambitus. The test
above the primary spines is much more closely packed with small pediceUariae differing
from those figured for Podocidaris sctdpta in the Revision of the Echini (pi. iv. fig. 15), in
having a shorter stem and a stouter head. The large specimen had also a single large
tridactyle, pyramidal pedicellaria, with slender valves leaving large oj)enings between
them above the base. The arrangement of the miliaries, as we find it in tJais species of
Podocidaris (PL XXXIV. fig. 14), recalls the somewhat more regular arrangement of the
secondaries and miUiaries in horizontal rows in some species of Magnosia and of Codio2^sis
as does the presence of large primaries near the ambitus or towards the actinostome.

The most characteristic differences, however, between the two .species are those of the
spines and the structure of the abactiual system. The spines are nearly as long as the
diameter of the test, flattened, and comparatively quite slender compared to the broadly
lanceolate shaped spines of Podocidaris scidpta. The shnft of the spines of Podocidaris
prionigera, although slightly contracted beyond the milled ring, and a trifle broader at a
short distance from it, immediately below that part of the shaft where the marginal serra-
tions commence, yet decreases very gradually in width, tapering more or less rapidly to a
point towards the extremity of the shaft. The serrations of the primary spines are promi-
nent, alternating on opposite edges of the flattened shaft ; there are not more than twelve
on each edge of a spine measuring 10 mm. in length ; the serrations commence only at a
distance of from one-quarter to one-third the length of the shaft from the milled ring.
The spines in alcohol were of a brilliant transparent semi-silvery lustre, with a yellowish-
brown basal portion. The test brownish -yeUow ; it is not ornamented with deep pits in
the median interamljulacral area as in Podocidaris scidpta, and the coronal plates carry
above the primary tubercles only the miliaries, irregularly arranged, upon which are sup-
ported the short-stemmed large-headed pedicellariae. The plates of the genital ring (PL
XXXIV. fig. 15) are arranged much as in Podocidaris scvlpta, the ocular plates, however,
are very much larger than those of Podocidaris scidpta ; they are elongated vertically, and

60 THE VOYAGE OF H.M.S. CHALLENGEE.

extend down towards the ambitus so far that the extremity of the poriferous zone is placed
at a point nearly half-way between the anal opening and the ambitus, far below its position
in Podociclaris sculpta. In both of these specimens the anal system was covered by five
plates (PL XXXIV. fig. 15) developed equally. The miliaries of the genital plates are larger
and more prominent than those of the coronal plates. The madreporic body is but little
developed, consisting merely of three to five indistinct pores. In the larger specimen the
genital openings are small l^ut sharply defined, and placed excentrically nearer the anal
edge, as they are in Podocidaris sculpta.

The proportions of the abactinal system are somewhat diff"erent in the two species.
In Podocidaris prionigera, the diameter of the test being 9 mm., the abactinal system is
6 mm., whUein Podocidaris scidpta it occupies a comparatively smaU part of the abactinal
region (see Revision of the Echini, pi. iv. figs. 6, 8). The actinal system also is compara-
tively larger in the proportion of 5 to 9 to the diameter of the test ; while it is only
as 2 to 5 in Podocidaris scidpta. On the actinal side the ambulacral suckers are large
and powerful ; they diminish in size towards the ambitus, and become more distant and
pointed as they approach the abactinal system.

Station 218. March 1, 1875. Lat. 2° 33' S., long. 144° 4' E. ; 1070 fathoms;
bottom temperature, 2"1° C. ; globigerina ooze.

Station 205. November 13, 1874. Lat. 16° 42'N., long, 119° 22' E.; 1050 fathoms;
bottom temperature, 2'4° C. ; grey ooze.

Podocidaris scidpta.

Podocidaris sculpta, A. Agassiz, 1869, Bull. Mus. Comp. Zool., vol. i.
Station 24. March 25, 1873. Ofi" Culebra Island ; 390 fathoms ; mud.

Ccelopleurus.

Ccelopleurus, Agassiz, 1840, Cat. Syst. Ectyj}.

Cailopletinis maillardi (Pis. V., VI., XXXVIII. figs. 7-9 ; PI. XLV. figs. 1-6).

Keraiaphorus Maillardi, Mich., 1862, Maill. Bourbon. Ann. A.

Ccelopleurus Maillardi, A. Agassiz, 1871, BuU. Mus. Comp. Zool., vol. ii. p. 456.

This remarkable Sea-urchin was first described by Michelin under the name of
Keraiaphorus. He did not, however, suspect its close affinities to the Arbaciadse, and
Llitken was the first to hint at its identity with Coilopleurus, which a comparison I
subsequently made of small specimens dredged by the " Hassler" with Michelin's figures
fuUy corroborates.

REPORT ON THE ECHINOIUEA. 61

The Challenger having collected a number of large specimens (PI. V. fig. 1) fully
equalling in size the original specimen of Michelin, I am now able to clear up many
points left doubtful, and to describe at length this interesting Sea-urchin.

On the actinal side the spines are of two kinds both in the ambulacral and interam-
bulacral areas. First, small, slender, more or less cylindrical, pointed, finely serrated,
secondary spines (PL VI. figs 20c and 21c) surmount the secondary tubercles intervening
between the primary rows, especially on the edge of the interambulacral plates adjoin-
ing the poriferous zone ; secondly, the primary spines which, near the apical system are
scarcely larger than the secondary spines, but are readily distinguished by their triangular
or flattened shape, though the ornamentation of the smaller primaiy radioles is similar to
that of the secondaries. As they become large the base of the shaft becomes more finely
granular, and the extremity of the spines fluted, ^\^th serrated edges ; this fluting and
serration exists only in the largest primary radioles, and is limited to the part of the
shaft included between the milled ring and the shoe. The spines increase very rapidly
in size, so that before reaching the ambitus there are in the ambulacral area from four to
five, more or less curved, varying in length from nearly the diameter of the test to fully
three times as much (PI. V. fig. 1, PI. VI. figs. 19a, b, c, 22a, h, c), and two to three of like
size on the ambulacral plates near the ambitus. Abnormal as these radioles seem at
first glance, the relationship of the genus to the Arbaciadse gives a very simple expla-
nation of the enormous growth of some of the primarj^ spines. The shaft of the larger
primary radioles is composed of two very distinct parts, the basal part, the extension of
the shaft beyond the collar, which is triangular, passing into an hexagonally fluted or
angular shaft (PI. VI. fig. 22a', c'), finely striated and more or less distinctly covered with
minute serrations on the edge of the fluting [which in the shorter primary spines extends
to the very tip or near its extremity (PL VI. fig. 19c)] surmounted by the smooth
polished portion of the shaft (PI. VI. figs. 19a, 22a, c), which is rarely straight, and
often very considerably curved, and which sometimes is twice as long as the diameter
of the test, and sometimes forms a mere tip to the coloured angular base (PL VI. figs.
19d, 22d). This tip is angular or triangular in younger specimens. As the primary
spines pass towards the ambitus they rapidly become shorter, flatter, more slender (PL VI.
figs. 19cZ, 22d), straighter, and immediately around the actinal membrane are reduced
again to slender spines, not more powerful than the secondary ones (PL VI. figs. 20c, 21c).

It is the identity of the smaller flattened tipped spines (PL VI. figs. 20&, 21 6)
around the actinostome with those of other Arbaciadse which shows plainly that the
principal part of the shaft of the radioles of this genus consists of an exaggerated
growth of the cap at the tip of the spine so characteristic of the Arbaciadse and
to which Desmoulins (Actes Soc. Lin. de Bordeaux, 1870) first called attention. This
cap, however, in the other species of the family is found only on the spines of the
actinal surface, and I inferred from the peculiar mode of locomotion of the common

62 THE VOYAGE OF H.M.S. CHALLENGER.

Arbacia of the east coast of the United States that it was intended to replace the
wear of the tip of the spines in moving about, a use to which the huge curved spines
of this genus, placed as they are above the ambitus, can hardly have been put, unless
possibly to raise the test high above the bottom and keep it in suspension ; this, however,
is probably not a common use of these radioles of the abactinal surface as although
slightly worn they are not sufficiently reduced to show extensive usage.

There are no notes with these specimens on their movements after they are brought
up in the dredge.^ We find as in all Arbacice the round-headed pedicellarise (PL VI. figs.
17, 18) occurring near the abactinal region, while the large-headed, triangular, long-
stemmed pedicellarise (PL VI. fig. 16) are found along the test towards the ambitus and
more abundantly near the edge of the actinal membrane. The large plates of the actinal
membrane are covered by numerous short-stemmed round-headed pediceUarise (PL V.
fig. 2). The colour of the base of the shaft of the primary radioles is brownish, of the
secondary spines many are of the same colour, but as many are of a brilliant carmine,
the white part of the primary shaft, its shoe, is often banded longitudinally with brilliant
vermilion or with rectangular spots of the same colour on the upper part of the shaft.
In large specimens only here and there a coloured primary spine is found, while in young
or smaller specimens the spines are nearly all brilliantly coloured (PL V. fig. 3), the
glistening white shaft of the large specimens being usually of a delicate pea-green colour,
which is well set off by the longitudinal bands or the spots of IjrilUant vermilion along
the shoe, the base of the shaft being a dark greenish-brown or red. In these specimens
the short flat spines near the actinal area are frequently banded and spotted like the larger
ones. In small specimens the secondary spines are all coloured (PL V. fig. 3), and near
the abactinal surface they are more or less club-shaped (PL VI. figs. 20, 2\d), much like
the iTidimentary temporary spines of the abactinal region of the Arbaciadse, only they are
articulated and not soldered to the test as is the case in the other genera of this family.

In a specimen measuring 41 mm. in diameter, the width of the ambulacral system
(PL VI. fig. 7) near the ambitus is as great as that of the interambulacral. In
the former there are twelve primary tubercles increasing rapidly in size from the
actinal opening towards the edge of the test, where there follow three to four very
prominent tubercles, which are again followed by smaller tubercles rapidly decreasing in
size and extending to the genital ring (PL VI. figs. 1-3, 5, 7). The scrobicular circles are
large, and adjoining primary tubercles are separated in the median ambulacral space by

' Quite a number of specmieiis of Ccslophurus floridanus, A. Agassiz, were dreclgeJ during the season of 1878-79
liy the " Blake." On placing them in a pail of water I found that they used their large spines as indicated above merely
to raise themselves otf the bottom when distm-bed, using the shorter, stouter tipped spines of the actinal surface for
locomotion much as the common Arbacia pitstulosa of the east coast of the United States. Their movements, however,
were jnuch slower than those of Arbacia jm^tulosa, which moves rapidly (see Revision of the Echini). The coloiu- of the
West India CcclopleHrus is quite well kept in alcohol, and I presume the same is the case for the Ccclopleurus collected
l>y the Oliallenger. ^vhich show like the Florida species a great range and beauty of coloration.

EEPORT ON THE ECHINOIDEA. 63

few secondary and miliary ones ; only in the region near the ambitus and towards the
actinal area do the small primaries occupy the whole of the interporiferous zone towards
the abactinal region. Near the actinal region in the last four or five plates of the
ambulacral area there are, in the angles of the plates along the median fine, deep elliptical
pits (PI. VI. fig. 7), of the size of the larger ambulacral pores, in which sphseridia are placed.

In the ambulacral area the tubercles are small, placed upon a prominent boss rising
sharply from a broad flat distinct scrobicular area (PI. VI. fig. 5). The poriferous
zone is broad, the pores large, forming more or less distinct arcs of three pairs round the
base of the primary tubercles (PI. VI. fig. 5) near the equatorial region of the test. The
pores become smaller, and are placed closer together towards the ambitus (PI. VI. fig. 7) ;
they are still smaller on the actinal surface. There is no tendency at the very edge of
the actinal opening towards the petaloid structure so prominent among other Arbaciadse
(PI. VI. figs. 3, 7, 8, 10, 11). In the interambulacral spaces there are not more than
from seven to eight primary tubercles, corresponding in size, except the last two upper
ones (PI. VI. fig. 6), to the adjoining ambulacral primaries ; they are also separated
along the median line by a few secondaries and miliaries. On the last five or six
interambulacral plates towards the abactinal region there are no primary tubercles, the
whole median space is bare (PL VI. figs. 1, 2, 6, 9a, 13) with the exception of the three or
four smaU secondary tubercles placed near the outer edge of the plates, and which, in the
other plates carrying primary tubercles, separate them from the poriferous zone. This bare
median interambulacral space is ornamented by a few flat, broad, inconspicuous miliaries,
and by smooth broad bands, somewhat raised (PL VI. fig. 6), forming ii-regular S-shaped
lines extending from the centre of one plate to the upper edge of the following plate
(PL V. fig. 1). A brilliant carmine band extends from the genital ring on the inner edge
of the secondary tubercles, separating the poriferous zone from the bare space. These
secondary tubercles are reduced in number as they approach the genital ring. The
genital ring (PL VI. fig. 4) is narrow, the anal edge is somewhat raised by a ring formed
of broad flat indistinct miliaries, the outer portions of the genital plates being smooth ; the
genital plates are connected, surrounding the ocular plates which are crescent-shaped,
smooth, with one or two diminutive notches, and with a slight hood-like cap over the
odd terminal tentacular opening.

The genital openings are large, placed near the outer edge, with the exception
of the opening on the madreporic genital which is on the edge of the plate, the mad-
reporic body occupying its central portion (PL VI. fig. 4). There are four large smooth
anal plates. The genital ring and ocular plates are of a vivid carmine, similar to the
vertical interambulacral bands. The actinal notches are not deep, but the grooves formed
by the lips for the attachment of the angular prolongation of the actinal meml^raue
covering the passage of the gills are quite prominent (PL VI. fig. 7). The pi-incipal
difierences in smaller specimens consist in the proportionally greater width of the

(34 • THE VOYAGE OF H.M.S. CHALLENGEK.

ambulacra! system (PL VI. figs. 8, 14), the absence or smaller number of the more
prominent secondaries and miliarias, the proportionally narrower poriferous zone, the
indistinctness of the S-shaped bands of the median interambulacral spaces, the slighter,
less deej), actinal cuts, and the comparatively smaller size of the genital openings ; these
last, as I have shown in the smaller specimens of another species from the West Indies,
are perforated quite late. The tentacles of the abactinal part of the test are flattened
pouches, pointed at the extremity, resembling those of our common Arhacia piistulosa, and
evidently, from their size in alcoholic specimens, capable of as great expansion as those of
that species figured in Revision of the Echini, pi. v. figs. 1, 2, 6-8.

The pedicellarias of Ccelopleurus agree well in the main with those characteristic of
the Arbaciadse, consisting of the two types, the short-headed, long-stemmed, globular
pedicellaria3 (PI. XLV. figs. 3, 4), so characteristic of the abactinal portion of the test in
Podocidaris and Arhacia, and the large-headed ones (PI. XLV. figs. 1, 2) occurring nearer
the ambitus.

Station 201. October 26, 1874. Lat. 7° 3' N., long. 121° 48' E.; 82 fathoms and
102 fathoms ; stones and gravel.

Amboyna; 100 fathoms, Octobers, 1874.

Station 192. September 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129 fathoms ;
mud.

DlADEMATID^.

Family Diadematid^, Peters, 1853, Monatsb. Akad. Berlin {emend.).

Diadema.
Diadema, Schynv., 1711, Thes. Imag. (Peters, emend.).

Diadema setosum.

Diadema setosa, Gray, 1825, Ann. Phil, (non Rumph).

St Vincent, Cape Verde Islands.

Cebu, Philippine Islands. January 1875.

Papeete Reef. September 1875.

St Thomas.

*A spidodiade ma.

Aspidodiadema, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 199.

This is a most interesting genus, intermediate between the Cidaridfe proper and the
Diadcmatidse. It has like the latter a thin test, with long hollow primary spines nearly
straight, and strongly verticillate, especially in the young. The miliary and secondary
spines are like the primary radioles, only shorter and proportionally slender (PI. VIII.

REPOET ON THE ECHINOIDEA. 65

fig. 10). This genus lias, like Centrostephanus, ten large plates on the buccal membrane
(PI. VIII. figs. 3, 7, 11, 14, 15) carrying miliary spines.

The abactinal system is, as in the CidariclEe, large and circular, but the genital and
ocular plates are uniform in size, and form a narrow ring as in Glyphocy2'>hus (PI. VIII.
figs. 4, 13) round the membrane covering, as in the Diadematidse, the large anal system.
In the genital ring of Centrostephanus rodgersi two of the ocular plates, those adjoining
the madreporic plate, are excluded from the anal system. There are in the ambulacral
system, as in Hemicidaris and Salenia, two vertical rows of large tubercles limited to the
ambitus and the actinal system (PI. VIII. fig. 9), and as in other Diadematidse the am-
bulacral system is broad compared to that of the Cidaridse proper (PI. VIII. figs. 5, 9).
The interambulacral system has, as in Cidaris proper, only two vertical rows of large
primary tubercles (PI. VIII. figs. 5, 8). The test is globular, much as in Amblypneustes.
The most remarkable feature of this genus is the structure of the ambulacral system ; the
plates composing it are, as in the Cidaridee, small, arranged in two vertical rows, the
plates are nearly of a size, and each plate is perforated by a pair of large pores placed close
together (PI. VIII. fig. 16). The pores are situated on the outside edge of the plates and
run in a vertical line (not undulating as in Cidaris) from the apex to the actinal system
(PL VIII. fig. 9). The primary tubercles are perforated and crenulated. The teeth are
grooved as in the Cidaridse and Diadematidse.

In Aspidodiadema tonsum the slender long-headed pedicellariae (PL XLII. fig. 5)
are remarkable for the small triangular base of the valve (PL XLIV. fig. 15). The
globular short-headed abactinal pedicellarise (PL XLII. fig. 4) differ from those of
Aspidodiadema microtuhercxdatmn (PL XLIV. fig. 18) ; in the latter the valves extend
into a stout, rather blunt point with smooth edges, while in Aspidodiadema tonsum the
short valves are scalloped on the edges and terminate in a powerful hook.

* Aspidodiadema microtuherculatum (PL VIII. figs. 10-16 ; PL XXXVIII. figs. 17,
18; PL XLIV. figs. 16-18).

Aspidodiadema mierotuberculatuin, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 199.

This is a larger species than Aspidodiadema tonsum (comp. PL VIII. figs. 1 and 10),
and is readily distinguished from it by the smaller number of miliary spines covering
the test, their irregular size, and by the more numerous, shorter, stouter, dark violet
primary spines carried on the interambulacral area. The colour of the test and spines of
all the specimens of this species collected by the Challenger was in alcohol of a- very dark
violet, the same is also the case with the large specimens of Aspidodiadema dredged
by the " Blake" dming the season of 1878-79.

In the median ambulacral spaces there are no large primary tubercles, only small
secondary tubercles, nearly of uniform size, placed on the inner angle of the ambulacral

(ZOOL. CHALL. EXP. PART IX. 1881.) I 9

66 THE VOYAGE OF H.M.S. CHALLENGER.

plates (PL VIII. fig. 11), forming two median vertical rows; these secondary tubercles
are slightly larger near the actinal edge of the test. There are in addition irregular lines
of miliary tubercles running transversely near the upper edge of the ambulacral plates
parallel with the trend of the pores (PI. VIII. fig. 16). The primary interambulacral
tubercles are perforated and crenulated as in Aspidodiadema tonsum. The ambulacral
system is separated from the interambulacral area at the actinal area by a slight lip as in
the Diadematidae (PI. VIII. fig. 11). The genital ring is comparatively narrower than
in the other species of the genus ; the ocular plates are wider than the genital plates,
and they are both covered by large, rather distant miliaries. The anal membrane is
strengthened by a number of plates forming two ii-regular rings (PI. VIII. fig. 13) round
the large anal opening ; they are covered by short slender diminutive spines. The inner
ring is composed of the largest plates. Plate VIII. fig. 15 shows the large size of the ten
buccal plates of this species which cover, when denuded, nearly the whole of the actinal
membrane. In a specimen measuring 26 mm. in diameter there are eight primary tubercles
on the interambulacral plates. In a younger specimen measuring only 10 mm. in diameter
there are five primary plates. The ambulacral tentacles are, like those of the Diadema-
tidse, pointed near the abactinal surface, and carry powerful suckers near the actino-

stome.

Station 298. November 17, 1875. Lat. 34° 7' S., long. 73° 56' W. ; 2225 flithoms ;
bottom temperature, 1-3° C; grey mud.

Station 299. December 14, 1875. Lat. 33° 31' S., long. 74° 43' W.; 2160 fathoms ;
bottom temperature, 1'1° C; grey mud.

Station 134. October 14, 1873. Lat. 36° 12' S., long. 12° 16' W.; 2025 fathoms;
bottom temperature, 1'6° C; globigerina ooze.

Station 122. September 10, 1873. Lat. 9° 5' S. to 9° 10' S., long. 34° 49 'W. to 34°
53' W.; 356 fathoms.

OfFMacio. September 11, 1873. 1700 fathoms.

*Aspidodiadema tonsum (PL VIII. figs. 1-9; PL XXXVIII. fig. 19; PL XLIL
figs. 4-6 ; PL XLIV. fig. 15).

Aspidodiadeina tonsum, A. Agassiz, 1879, Proc. Am. Acad.,, vol. xiv. jj. 199,

This species is readily recognised by the uniform coating of short, slender miliary
spines, which cover the whole test, and by the small number of long slender radioles, some
of them nearly three times the diameter of the test, carried upon the interambulacral
system (PL VIII. figs. 1-3). The genital ring is remarkable for the uniform size of the
ocular and genital plates, and the close granulation with which they are covered, with the
exception of one or two larger tubercles placed near the anal edge of the plates (PL VIII.
fig. 4). Immediately round the anal tube there are five large elliptical plates and one

REPOET ON THE ECHINOIDEA. 67

small plate covered with miliaries, and each carrying slender spines, arranged in thick
tufts (PI. VIII. figs. 1, 4, G), so that in specimens which are not denuded, the whole
abactinal system is thickly covered with miliary spines (PI. VIII. fig. 1). There are in
specimens measuring 1 6 mm. in diameter only eight or nine interambulacral plates, each
carr}'iug only one large primary tubercle ; the scrobicular area occupies, as in the Cidaridae,
nearly the whole of the plates (PL VIII. fig. 5), the rest of the plate being fiUed with
miliaries of uniform size, arranged much as in the Cidarid^. In the ambulacral system
there are from four to five small primary tubercles, increasing in size from the actinostome
to the centre of the test, forming two short vertical rows much as in Hemicidaris. When
alive the colour (in specimens collected by the " Blake ") of the miliary spines covering
the test is yellowish-pink, the primary spines somewhat darker, or of a light violet tint.

Off Macio ; 1700 fathoms. September 11, 1873.

Station 170. July 14, 1874. Lat 29° 45' S. ; long. 178° 11' W. ; 630 fathoms;
bottom temperature, 4'0° C. ; rocks. Kermadec Islands.

Station 171. July 15, 1874. Lat. 28° 33' S. ; long. 177° 50' W. ; 600 fathoms;
bottom temperature, 4'0° C. ; rocks.

Off Cebu ; 100 fathoms.

Echinothrix.
EchinotTirix, Peters, 1853, Monatsb. Akad. Berlin.

Echinothrix calamaris.

Echinus calamaris, Pall. 1774, Spic. ZooL

Echinothrix calamaris, A. Agassiz, 1872, Revis. EcL, part 1, p. 120.

Kandavu Reef. Fiji Islands.
Tahiti Eeef.
Cebu Eeef.

Echinothrix turcarum.

Diadema turcarum, Schynv., 1711, Thes. Imag.
Echinothrix turcarum, Peters, 1858, Monatsb. Akad. Berlin.

Honolulu.
Kandavu Reef.

* Micropyga.

Micropyga, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 200.

This genus, with its flattened test and short spines, is closely allied to Astropyga, from
which it mainly differs in the small size and the structure of the abactinal system, which

68 THE VOYAGE OF H.M.S. CHALLENGER.

resembles more that of Centrostephaniis and Aspidodiadema, and in the greater rigidity
of the test, as in Diadema ; the bare sunken median interambulacral space extending from
the apical system towards the ambitus, so characteristic of Astropyga, is in this genus nar-
row; it bears, as in Astropyga, small primary tubercles, forming two vertical rows along
the median ambulacral line. The primary tubercles of the interambulacral areas above the
ambitus are placed in the centre of the plates, and arranged in one principal vertical row,
with irregular rows of smaller secondary tubercles. As in Astropyga the actinal floor is
thickly covered with large primary tubercles, deep actinal cuts are present, the poriferous
zone is narrow, the pores are in pairs arranged in two vertical rows, the spines of the
abactinal surface are short and slender like those of Astropyga j)roper, while on the actinal
side they are more or less club-shaped, or trumpet-shaped, resembling somewhat the
actinal spines of A sfhenosoma and Phormosoma (but they are not tipped with a hoof as in
some species of these genera), with which both this genus and Astropnjga have many
points in common, forming a connection as it were between the Diadematicte proper and
the Echinothuridge. The primary and secondary tubercles are perforate, but not crenulate.
The primary and secondary ambulacral and interambulacral radioles are similar in structure,
with exceedingly fine verticillations, forming in older specimens a delicate longitudinal
striation.

In Micropyga the long-headed pedicellariae closely resemble those of the Diadematidse.

*Micropyga tuberctdata (Pis. VII., XXXIX. figs. 1, 2; PI. XL. figs. 26-28; PI.
XLIV. fig. 37).

Micropyga tuherculata, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. \). 200.

This is a large species, measuring no less than 200 mm. in diameter, the actinal surface
is flat (PI. VII. fig. 2), the ambitus making a sharp angle with it, and the test is regularly
arched towards the low flattened abactinal surface. On the actinal interambulacral spaces
the primary tubercles are arranged in a single horizontal row, occupying, with the exception
of a few miliaries, the whole of the coronal plate, they form a close pavement (PI. VII. figs.
2, 4), and increase uniformly in size from the actinal edge to the ambitus, making more
or less irregular vertical rows, radiating from the actinostome, there being from six to
seven rows at the ambitus. In the ambulacral areas the primary tubercles, arranged
in only two vertical rows, increase regularly in size towards the ambitus (PI. VII. figs.
2, 4), where they as well as the interambulacral tubercles are largest, and while occupying
there nearly the whole of the ambulacral plates between the poriferous zone, become
reduced on the abactinal surface to small secondary tubercles placed in the centre of the
ambulacral plates, which carry, besides, a few small miliaries or granules, occurring irregu-
larly on the plates (PI. VII. fig. 1, 7). The same rapid change takes place in the size of
the primary tubercles of the interambulacral areas of the abactinal surface (PI. VII. fig. 1) ;

REPORT ON THE ECHINOIDEA. 09

immediately past the ambitus tlie primaries are reduced to a single vertical row of a
much smaller size than those of the actinal surface, placed in the central part of the
coronal plates and extending neai'ly of uniform size to the abactinal system. The rest of
the plate (PI. VII. fig. 5) carries a few secondaiy tubercles and miliaries irregularly
arranged, the former forming indistinct vertical rows, the latter indistinct horizontal lines.
The poriferous zone is of nearly uniform width, from the actinal edge to the apical
system. The actinal cuts (PL VII. fig. 3) encroach deeply upon the interambulacral
plates ; there is no tendency to expansion of the poriferous zone at the actinostomc
The bare median interambulacral spaces (PL VII. fig. 1) as seen from above are ill-
defined, and have not the prominence they take in Astropyga. The pedicellarise
of the lower surface are narrow-headed, elongate, with a long stem; they are similar
in the ambulacral and interambulacral areas of the actinal and abactinal sides.
The apical system (PL VII. fig. 6) is characterised by the small anal system covered
with numerous irregularly-shaped plates, carrying few miliaries near the genital edge.
The genital plates are uniform in size, pentagonal, with rounded points ; the genital
openings are large, and are placed near the pointed extremity as in the Diadematidse.
The macbeporic body is not prominent, the ocular plates are hexagonal, they carry five to
seven miliaries irregularly placed like those of the genital plates near the anal edge.

In younger specimens (PL VII. figs. 7-9) the principal differences consist in the
comparatively larger size of the primary tubercles of the abactinal region, their smaller
number on the actinal surface and the larger size of the plates covering the anal system.
The genital plates are less elongated, the ocular and genital plates resembling at this early
stage in their arrangement that of the genital ring of Aspidodiadema. A young speci-
men measuring 26 mm. in diameter shows that in this species the changes due to growth
are readily traced ; they consist in the smaller number of coronal plates and the smaller
number of the primary and secondary tubercles, but their ultimate arrangement is
already indicated in this smaller specimen. The spines are, however, proportionally much
longer, equalling in length nearly one-haLf the diameter of the test. The spines in this
specimen are still white, only a few contain a slight trace of light violet pigment matter
tinting the extremity of the spines or forming irregular patches or transverse bands on the
spines. The imbricating plates of the actinal membrane are very distinct. The diff'erence
in size between the genital and ocular plates of the anal ring is hardly appreciable, it
was already quite small in that of the young specimen figured on Plate VII. fig. 9.

In large specimens the colour of the test in alcohol is a dark violet, the spines of a
dark violet brown.

Station 174. August 3, 1874. Lat. 19° 10' S., long. 178° 10' E. ; no fathoms on
label. Text. 255, 610, and 210 fathoms; bottom temperature at 600 fathoms, 37° C;
globigerina ooze.

Station 219. March 10, 1875. Lat. 1° 50' S., long. 146° 42' E., 150 fathoms; mud.

70 THE VOYAGE OF H.M.S. CHALLENGER.

Off Cebu; 100 fathoms. January 22, 1875.

Station 204. November 2, 1874. Lat. 12° 43' N., long. 122° 10' E. ; 100 fathoms
and 115 fathoms; mud.

Astropyga.

Astropyga, Gray, 1825, Ann. Phil.
Astro'pyga pulvinata.

Gidarites pulvinafa, Lamk., 1816, Anini. sans. Vert.

Astropyga pulvinata, Agassiz, 1846, C. R. Ann. Sc. Nat., vol. vi.

In a young specimen of this species measuring only 19 mm. in diameter, the small size
of the actinostome, 5*5 mm., is quite exceptional, as one of the principal features which
distinguishes the old specimens of Astropyga pulvinata from Astrop)yga radiata is the
projDortionally large actinostome ; the tubercles of the actinal surface are in this small
specimen of quite uniform size in both areas, near the actinostome the large primaries
appearing only near the ambitus. On the abactinal side the special features to be noticed
are the crowding of the small ambulacral tubercles in the upper part of the zone and
the existence of a very prominent vertical row of large primary interambulacral tubercles
flanking the poriferous zone and extending well towards the abactinal area. The bare
median interambulacral spaces extending from the abactinal area are well defined, and the
large bright violet spots existing on each coronal plate on the outer edge of this bare area
extend to the ambitus. The anal tube of this young specimen is, as in all young
Diadematidse, long, and rises prominently above the anal system. On compaxing this
small specimen with two smaller specimens of Astropyga radiata collected at the
Philippines by Dr Semper we can at once distinguish the young of the two species by
the different as23ect of the actinal sui'face, which in the young of Astrop>yga radiata is
somewhat convex without presenting the close uniform tuberculation of that of the young
of Astropyga pidvinata. In the specimen oi Astropyga radiata, measuring 15 mm. in
diameter, the actinal opening measured 6 mm. In the other, measuring 12 '5 mm., the
actinal opening was nearly 6 mm. or larger than in the young of Astropyga pidvinata,
measuring 19 mm. in diameter. The pentagonal outline already noticed in a small
specimen of Astropyga radiata, measuring 36 mm. in diameter, becomes more prominent
in the smaller specimens measuring 15 mm. and 12 '5 mm. in diameter. It is very evident
from the above that in both these species we have considerable variation in some of the
characters which have thus far been employed to distinguish the two species.

Unfortunately the series of specimens at my command are not such that a comparison
can be made of corresponding stages of the two species

Station 190. September 12, 1874. Lat. 8° 56' S., long. 136° 5' E; 49 fathoms;
bottom temperature, 23'9° C. ; mud.

REPORT ON THE ECHINOIDEA. 71

Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E.; 28 fathoms; mud.
Honolulu; 18 fathoms. July 30, 1874.

ECHINOTHURID^.

Family Echinothuridze, "Wj'ville Thomson, Depths of the Sea, 1873, p. 164.

WyviUe Thomson, 1874, Echinoidea of the "Porcupine," Trans. Roy. Soc, vol. clxiv. part 2, p. 730.

The characteristic overlapping of the ambulacral coronal plates has been well
described and figured by Thomson (Echinoidea of the " Porcupine," Trans. Eoy. Soc, vol.
clxiv. part 2, p. 730, pi. Ixv. and following ; see also A. Agassiz, Eevision of the Echini,
pi. ii.''). I have here given some additional details mainly regarding Phormosoma , and
have also called attention to the changes in the family characters due to growth.

Thomson speaks, in the Depths of the Sea, of the vermicular movements passing-
through the test of Asthenosoma, when it assumed on deck what appeared to be
its normal form and attitude. When handled, the test moved and shrank from the
touch, and had much the feeling of the disk of a Solaster or other large Starfish. I
have in one of my letters to the Superintendent of the U. S. Coast Survey ' spoken of
the globular form of the species of Asthenosoma when they came up in the trawl, but I
can only corroborate the statements of Thomson regarding the peculiar movements of
the test of specimens when on deck, due undoubtedly to the great mobility of the plates
of the test. It is quite dangerous to handle these specimens when alive (or even in
spirits) ; the wounds they made with their numerous minute sharp stinging spines pro-
ducing a decidedly unpleasant sensation, accompanied with a slight numbness, fully as
painful as that occasioned by the stinging of a Physcdia.

Some of the species of Echinothuridse here described, show that some of the important
characters upon which this family is distinguished from the Diadematidse may become
gradually obliterated, and the existence of such species as Phormosoma asterias, Astheno-
soma gracile, and Phormosoma 7^igidum, where the lapping of the plates is reduced to a
minimum, if it exists at all, and where, as in all the young of the group, the distinction
between the actinal and abactinal surfaces, so striking in the larger sj)ecimens, does not
exist, and develops only with increasing size, show how difficult it is to separate this
group of Echinids as a distinct family from the Diadematidse.

The lapping of the coronal plates in the Echinothuridae is not so absolutely a charac-
teristic feature of the famUy as has been supposed. It exists already well-developed in
Astropyga (PI. X." fig. 9), but with this important difi"erence, that the overlapping of
the plates is in the same direction in both areas. The lower edge of the plate passes
under the upper edge of the preceding plate. In Echinothr-ix and Diadema also, the shape

1 Letter No. 3, BuU. Mus. Comp. Zool., vol. v., 1879.

72 THE VOYAGE OF H.M.S. CHALLENGER.

of the coronal plates is already markedly pistol-shaped, the sutures do not extend hori-
zontally, or nearly so from one area to the other as they do in the other Desmosticha,
and we can trace a slight bevel in the same direction as that of Astropyga in a section of
the junction of adjoining coronal plates. In Astropyga the plates being narrower and
more elongated, and, consequently, more numerous, the pistol shape of the coronal plates is
very striking, and is as fuUy developed as in some stages of Asthenosoma , lapping slightly
along the median line. Another very characteristic feature of the Echinothuridse we also
find in Astropyga. I have called attention to the splitting up of the interambulacral
plates into irregularly sliaped independent plates, thus producing interambulacral
areas which, as in the Pala3echinid8e proper, are composed of more than two vertical
rows of plates. The fact that there are more than two vertical rows in the ambulacral
areas in the Desmosticha as well as Pateechinidae I have referred to on a former occasion.
In Astropyga we find that the large interambulacral plates from the edge of the ambitus
nearly to the abactinal system, as far as the external line of primary tubercles extends,
are made up of two very distinct plates (PL X.'' fig. 9), so that in Astropyga as well as
in Fhormosoma we have an interambulacral area in which the vertical zones are
not composed simply of two rows of plates but of four, and in which the primary
tubercles of the actinal surface recall very strikingly from their deeply sunken areolae,
those of ArchcBOcidaris and Fhormosoma. Astropyga must therefore be considered
a genus either belonging to the Echinothuridae, or at any rate possessing some of the
most characteristic features of both the Diadematidae and Ecliinothm-idas. The inter-
ambulacral plates of the actinal surface of Astropyga difler from those of Phor-
mosoma in which the primary tubercles are deeply sunken ; but when seen from
the interior, the deep hollow primary tubercles of the genus connect the solid
tubercles of Echinothrix and Diadema with the hoUow and deeply sunken tubercles
of Phormosoma proper. The shorter and somewhat club-shaped spines of the actinal
surface, like those of Mkropyga, resemble somewhat the shorter hollow-tipped spines of
the actinal surface of the Echinothuridae.

In most of the Desmosticha with spherical tests a certain amount of bevelling occurs
in the joints of adjoining plates, this bevelling corresponding more or less to the
curvature of the test ; and when there are a large number of plates in a thin test, the
edges appear parallel, while the direction of the joints is readily traced in genera having
few coronal plates and a comparatively thick test. In Echmaraclmius the upper edge
of the plates of the ambulacral system within the petals is inclined towards
the abactinal system. It certainly seems impracticable to base a classification of the
Echinoidea on this character of the imbrication or abutting of the coronal plates in the
difi"erent groups of Echinids as has been proposed by Keeping.^

Both in the Cidaridae and in the Echinothuridge in which the imbricating plates of

' Palaeozoic Echini, Quar. Joiu'. Geol. Soc. London, 1876, vol. xxxii. p. 40.

REPORT OX THE ECHINOIDEA.

73

the actinal membrane are pierced for the passage of amlmlacral tentacles, new plates for
this membrane are formed by becoming detached from the ambulacral zones. It is
readily seen on examining a large Astheiiosoma how the small ambulacral j)lates of the pori-
ferous zone become isolated and gradually increase in size laterally, until they eventually
meet the corresponding plates from the adjoining ambulacral zones; and thus, in spite of
the increasing size of the actinal opening with advancing age, it is kept covered by the
newly-formed plates detached from the edge of the test at the point of contact with the
actinal membrane. These plates extend on one side towards the median line of the
ambulacral zone, and in the other direction meet on the median line of the interam-
bulacral zone. In the younger stages there are plates in the extension of both the
ambulacral and interambulacral areas.

Lovdn and Ludwig have shown that the imbrications of the plates so characteristic of
the Palaeozoic Eehinoidea is not completely lost, even in Spatangoids; and from the peculiar
mode of growth of the plates, regularly concentric round a nucleus, a thinner edge is
formed, which maintains by its encroachment on adjoining plates a considerable degree of
mobility in the tests of the globular Spatangoids during their growth. And when we go
back to the very earliest stages of growth of the plates composing the test of Echinids,
when they are made up of mere Y-shaped rods, we can readily see that the lapping of the
coronal plates is a feature very characteristic of all Echinoid structures from the very
nature of the basis of the calcareous plates composing the test ; whether it be in a
Palaeozoic Echinus, a Cidaris, a Spatangoid even, or a Crinoid, a Starfish, or a Holo-
thurian, it is found occurring in all the plates.

The gills pass as in the Diadematidse proper between the edge of the plates of the
test jjroper and the imbricating plates of the actinal membrane, though the openings
through which they pass can scarcely be called cuts ; they are small indentations, the
result of the space left between the curved edge of the last interambulacral plate, and
the next plate of the actinal membrane, or of the notch formed by the overlapping of the
extremity of the last plate over the side of the next coronal plate. The gills appear at a
very early stage; in the youngest specimens, they are mere digits, or a simple fork in the
smallest specimens I have examined. The gills become quite prominent in some of the
species (see PL XIX." fig. 1, Asthenosoma tessellatum). New plates of the anal system,
on the contrary, ajapear to form next to the anal opening, and are gradually pushed away
towards the genital plates, though evidently additional plates are also formed by the
.splitting of the older and larger plates, especially those adjoining the abactinal extremity
of the interambulacral area.

Judging from the large size of the genital openings and the large size of the eggs in
one of the species, this group of Sea-urchins is probably viviparous; and we find here also,
in the great distance at which the genital openings are placed from the anal system, some-

(ZOOL. CHALL. EXP. — PART IX. — 1881.) I 10

^^

-^ THE VOYAGE OF H.M.S. CHALLENGER.

thing ot the same structure which ends in some of the Clj-peastmids in the genitd
opeiSngs being placed outside the genital plates. j , ,i,„

We find tfai it is in the older groups, such as the Cidarida, and Sa emda,, that the
ocular plates attain their greatest development, less marked, as Wn has P"'>t«l »» ■
among the Spatangoids and still less conspicuous in that most recently devebped of all
Minoid types, the Clypeastroids. As far as the genital plates are concerned they are by
no means lays connected with the genital pores, .s the oeu ar pore rs — X »-
nected with its plate. The genital opening has no such morphologrcal -g-^J'' '» "^
relation to the test as the ocular pore, and is m the first place not ^e-lop <1 - y°-8
Eehmids; and furthermore these plates form a part of the coronal system at that time
Tn the penhrgs of the genital system may be placed in the interambulaeral area enf^ely
ontlide of the inital ring, a, is the case among many of the Clyi>eastroKls, and even, as I
ZTeLZ in the vivip:;ous Cidarid», the greater part of the genital openings are no
p^ed in the genital ring, thus clearly showing the want of connectron between the
^ caUed .enita? plates anS the external opening of the genital organs m genera m which
TheTe plates attain their greatest development and in which they retain the. normal

shape even in the adult. ^ i ^„ PlotA« XTT "

The young specimens of PhorT^iosoma and Asthenosoma, figured on Fiates Ail.
XVIII XVIII.^ show some interesting points in the development of the abactma
tstem'of the poriferous zone, of the actinal surface, and of the structure of the coronal
;C which throw considerable light on the afiinities of the EeWt7d. to other
group of the Echinoidea. I have already in the Revision of the Ech.m (pl- -^^^^^
Lured a very smaU Asthenosoma hystrix (3-1 mm. in diameter), and caUed attention to
the^dSnentary separation between the plates of the ambulaeral and mterambulacra
tas to the absenc'e of a regular abactinal system, and also of an ^^^^^^^
membrane. In the smallest specimen of Phormosoma collected by the ChaU ng^
(Phormosoma uranus) (PL XVIII.^ fig. 12), measuring 8 mm. m diameter, the actma
membrane was already covered with plates, but plates differing m their arrangement
from those of the adult, and presenting features which associate these young stages iar
more with the Diadematid^ proper than with the Echinothurida;. , ^ o1

The actinal membrane has, as in Centrostephanus and Echinothn., ten large buccal
plates, forming a nearly closed ring round the actinostome, with an outer ^-^SfJ^'^^
plates ten ambulaeral perforated for tentacles, and ten interambulaeral P^- -^ This
Le structure is stiU seen in a young specimen o^ Phormosoma ^-^ (P]^™;^
fi^ 7) measuring no less than 49 mm. in diameter, while m a specimen oi Asthenosoma
aracile ? (PI XII.^ fig. 6), measuring 24 mm. in diameter, the imbricatmg plates are
Teady well developed, but have not as yet united with the adjoining interambulaeral
Ites as they do in the adult. The same is the case in a young Phonnosom.. harden um,
tZZT^e mm. in diameter (PI. XVIII.^ fig. 4). In this stage the young Echmo-

REPORT ON THE ECHINOIDEA. 75

thuridse closely resemble what I have temporarily regarded as the young of Micropyga
tuherculata (PL XVIII/ figs. 10, 11; PI. VI." figs. 6, 7). We find there the actinal
membrane carrying ten buccal plates, with other plates in the extension of both the
ambulacral and iuterambulacral areas (PI. VI.^ fig. 7), but only the buccal plates and the
two ambulacral plates adjoining the test are perforated for tentacles, while in the yoimg
of Phormosoma, with a corresponding stage of development of the actinal membrane,
the ambulacral actinal plates are all perforated. In the young of Micropyga (PI. VII."
fig. 6) the apical system at an early stage shows the structure characteristic of the genus,
while the anal system is left comparatively bare of plates. This is not the case with
the apical system of the young of Phormosoma or of Asthenosoma. The anal system
(PL XVIIL" figs. 2, 5, 6 ; PL XII." figs. 2, 5, 7) is at an early stage covered by a large
number of distinct plates, while the genital ring of corresponding stages is, on the
contrary, often quite indistinct from the anal plates (see PL XVIII. " fig. 6); while in
other cases (PL XII.* figs. 5, 7 ; PL XVIII." fig. 3) the genital and ocular plates are
more distinct perhaps from the anal system than they are in older stages, especially in
those species where the genital plates show a tendency to split up into distinct plates,
the upper plates apparently belonging to the anal system, or where the genital plates
encroach far into the median interambulacral space^ at the abactinal extremity of the
test, separating completely the adjoining interambulacral plates. So that, judging from
the few young Echinothuridse wliich have been examined, the new plates of the actinal
membrane are primarily formed by becoming separated from the ambulacral plates of
the test, while additional interambulacral plates seem to be formed at the abactinal
pole from the pushing down of large marginal plates of the anal system on each side
of the genital plate.

This whole development of the abactinal and actinal systems of the Echinothuridse
and Diadematidse, plainly shows a far closer structural relationship between them and
the coronal plates than is apparent when studying the regular Desmosticha, in which
the contrast between the compact abactinal system, and the nearly bare actinal
membrane with the coronal plates is most apparent. In fact, the structure of the aj)ical
and actinal systems of the Spatangoids and Clypeastroids shows the close connection
existing between them and the coronal plates, and also plainly shows that both these
systems are but modifications of the actinal and abactinal extremities of the coronal
plates, as is more plainly seen to be the case in the Starfishes and Ophiurans and in
the Holothurians, where the coronal plates are reduced to their simplest expression.

The coronal plates of the youngest specimens of Pharmosorna (PL XVIII.' figs.

' See the great extension of one of the genital plates in Heterodiadema libycum of Cotteau. This was supposed to
have been the anal opening. In Cotteau's figure (pi. xv., 5 fasc, Echin. Algerie) it is clear that it enters, as in the
Echinothuridse, deeply into the interambulacral spaces, but not all, only into one on account of the inequality in size
of the genital plates.

76 THE VOYAGE OF H.M.S. CHALLENGER.

1, 2, 5, 12) and Asthenosoma show but the shghest possible trace of the lapping of the
edge of the plates of the ambulacral and interambulacral areas.

It is only in somewhat older stages (PI. XII." figs. 4, 5 ; Pis. XVIII., XVIII.= fig.^.
3, 6, 7) that the lapping of the sutures becomes apparent, or that the interstices between
the plates are formed ; unfortunately there are not among the Challenger specimens
enough small specimens to enable me to open a sufficient number of stages to examine
the changes in the imbrication of the plates due to growth.

There are, however, among the Echinids of the last " Blake " expedition a large
number of young stages both of Phormosoma and Asthenosoma, and I hope to return
to this subject in my final report on the " Blake " Echinoidea.

On the abactinal surface the arrangement of the tubercles characteristic of the adult
seems to be developed at a comparatively early stage (see young of Asthenosoma peUucidurn,
PL XVIII. of Phormosoma tenue, and Phormosoma luculentum, PI. XVIII.''), and the
same is the case with the characteristic features in the great development of the primary
tubercles of the actinal surface (see PL XVIII. figs. 1, 4, 8, and PL XVIII." figs. 4, 7).

The irregularity of the course of the poriferous zone on the actinal surface is not
characteristic of the adult alone. In the earliest stages of Phormosoma, which I have
thus far examined (PL XVIII.'^ figs. 4, 7 ; PL XII. " figs. 3, 6, 8), the same iiTegularity
already exists, the poriferous zone extending in a sti'aggling line of pores from the
ambitus to the actinal membrane. The poriferous zone of the abactinal surface in the
young stages is also narrower than in the adult and is confined mainly to the outer edge
of the ambulacral area, extending in a more or less irregular undulating zigzag line of pairs
of pores from the ambitus to the abactinal system (PL XII." figs. 4, 5, 9 ; PL XVIII." fig.
6) , and the pores attain only in later stages the characteristic arrangement of the adult.

In the young Phormosoma the small intercalated plate of the poriferous zone is
not placed as it is in the adult about halfway between the outer edge of the ambulacral
zone and the median line, but is found close to the outer edge, gradually passing with
increasing age and size towards its more central position (Pis. XVII. and XVIIL).

Although in one of the species {Phormosoma luculentum, PL XVIII."^ fig. 3) the definite
arrangement of the pores characteristic of that species was already perceptible in a
specimen measuring not more than 36 mm. in diameter, the alternate arrangement of the
poriferous zone seems to be attained earlier in Phormosoma than in Asthenosoma (see PL
XVIIL) ; though in a young Asthenosoma {A. gracilef), measuring 30 mm. in diameter,
the poriferous zone was already separated into its two components much as in the adult.
In aU the young Echinothuridse in which the imbricating membrane of the actinal
surface was partly developed, the gills are already present, though in the early stages they
appear as simple diminutive forks, and soon increase in size to form somewhat more fan-
shaped appendages, with three to four short digits (PL XII.* fig. 6, PL XVIII." fig. 4, 7) ;
but in the young as in the old, even when highly developed, as in Asthenosoma tessellatam,

REPORT ON THE ECHINOIDEA. 77

the gills do not pass through cuts in the test so prominent in the Diadematidae, but force
their way through the membranous space between the coronal plates and the actiual
membrane proper at the angle of the poriferous zone and interambulacral area.

The discovery of recent Echinothurid^ has naturally led to a renewed discussion of
their affinities with the Palseechinidie and other Palaeozoic Echinids, and more particularly
of the systematic relations of the Palteechinidfe to the Desmosticha. The relationship to
the Cidaridse and Echinothuridge is certainly not very remote, as will be seen when we
come to compare the apical and actinal systems of the Cidaridae with those of the
Palaeechinidse, and the structure of the primary tubercles of the actinal surface of the
recent Echinothuridse to the primary actinal j)lates oi ArclicBOcidaris and Eocidaris.

As far back as 1857 Mtiller^ called attention to the imbricating plates of the test,
not only of Lepidocentrus but also of Archceocidaris, and both Loven^ and myself
called attention to the imbrication of the coronal plates of the Perischoechinidse as a
general character of the gi-oup. In 1874' I called attention to the fact that Mtlller's
observation had escaped the attention of the American Palaeontologists, to whom we owe
the description of so many of the genera of this interesting group of Echinids. Later
English writers'* on the subject, who have, in consequence of the discovery of the recent
genera Asthenosoma and Phormoso'nui with the imbricating coronal plates, taken up the
question again seem likewise to have completely overlooked what Mliller had published
on the subject.

There are in the collection of the Museum of Comparative Zoology a number of
specimens of Palaeechinidae, which with the fine collection of Palajechinidaj from the Bur-
lington Umestone made by Mr Wachsmuth, which he has been kind enough to lend me
for inspection, has enabled me to examine the greater number of the genera thus far
described, and to satisfy myself, from personal examination, of the structure of the
coronal plates of the Perischoechinidae.

As has been pointed out by Etheridge '' there are two very distinct types among the
Palaeechinidae. Those in which, as in Lepidesthes, Lepidechinus, Echinocijstites, Lepidocen-
trus, and the like, we have comparatively thin coronal plates imbricating like the tiles of a
roof both towards the actinal and abactinal region as well as laterally, and those in which,
as in Oligoporus, Pcdceechiims, and Melonites, the coronal plates are of great thickness and
on which the plates abut by more or less bevelled edges but still retain the same lateral
and vertical (actinal or abactinal) direction. This division, of course, depends entirely
upon the thickness of the plates of the test, and is not based upon important structural
features, though the facies of such genera as Oligoporus and Lepidesthes would at the first

» J. Mliller, Ueber neue Echinoderinen des Eifeler Kalkes, Berlin, 1857 ; Abhand, d. Berlin Akad. fiir 1856.

* S. Loven, Etudes sur les Echinold^es .

^ Revision of the Echini, part 4.

« J. Young, Geological Magazine, vol. x. p. 301, 1873 ; W. Keeping, Quar. Jour. Geol. Soc, vol. xxxii. p. 35, 1876.

^ R. Etheridge, Jr., Quar. Jour. Geol. Soc, 1874, vol. xxx. p. 307.

78 THE VOYAGE OF H.M.S. CHALLENGER.

glance appear to indicate very widely differing structural characters. In the same way,
widely separated as Archceocidaris and Qligoiwrus appear, the existence of such genera
as Lepidocentrus, and PJiolidocidaris, shows that even the characters which at first sight
so strongly contrast in Melonites and Archceocidaris may gradually disappear, although
undoubtedly the type to which Melonites, Oligoporus, Palceechinus, and the like belong
would lead us more directly as far as the structure of the coronal plates is concerned to
the abutting plates of the Echinids of the present period, which as I have attempted to
show are really all to a certain extent bevelled at the edges. This bevelling depends
first uj)on the curve of the test and in the second place upon the thickness of the test,
while such decidedly imbricating coronal plates as those occuppng the actinal surface of
the test in ArchcBOcidaris and the like, and on which we find also a single large primary
tubercle developed, lead us directly to the Echinothuridse, and to such types as Phormo-
soma, which are evidently not very difi"erent in their structure from the Silurian ArchcBO-
cidaris ; and at the present day the Diadematidse, especially Astroioyga, still retain traces
of the existence of more than two rows of interaml:>ulacral plates and of the imbrication of
the coronal plates, within the ambulacral and iuteramliulacral areas, so prominently
developed in the Echinothuridse of the present day. This is not the only family in
which we find interambulacral areas with more than two rows of coronal plates. In the
remarkable genus Tetracidaris of Cotteau, the double row of interambulacral plates on
each side of the median line is not limited as in Astropyga to a few plates on the actinal
sides of the test. In that genus we find only a short part of the interambulacral area
near the abactinal part of the test where the normal number of interambulacral plates are
present, while in the rest of the test, with the exception of the few plates near the apical
system, the interambulacral areas consist of four rows of primary plates.

The very peculiar splitting of the vertical rows of coronal plates noticed by Quenstedt
in Melonites ^ seems to point to some structural peculiarity in the PalseechinidBe such as
I have described in the breaking up of a single interambulacral plate in our recent
Echinothuridge. It shows, at any rate, what some of the other genera of Palajechinidae
plainly show, that we find it impossible to define the number of rows of coronal plates in
the test just as we find it impracticable near the apical system of the regular Echinids to
ascertain how many rows of interambulacral plates there are present, as they appear in
that region of the test packed in as they best can find place and take up tlieir regular
and symmetrical arrangement only later, while we may observe that in the Pal£eechinida3
this symmetrical arrangement never takes place, the vertical rows of plates running in as
best they can, thus forming another important embryonic character of the Palaeechinidse.

From an embryological and pal^ontological standpoint perhaps no more important
view has lieen taken than that of Loven regarding the nature of the apical system of the
Echinidse, which he developed from a comparison I had at first indicated of the complete

' Quenstedt, Pal. Deutsch., 1872 to 1875, vol. iii. p. 381.

REPORT ON THE ECHINOIDEA. 79

analogy of the plates of the young Starfish to those of the Crinoids, and which he has
most suggestively extended to the Echinids, and which most naturally explains the great
number of plates we find both on the ambulacral and interambulacral plates of the
Palseechinidse, in which as in the Crinoids the plates composing the calyx subdivide into
numerous joints or into numerous plates to form the test of our oldest known Sea-urchins,
which- thus still show most unmistakably their systematic afiinity to the Crinoids.

Unfortunately, in the types with thin coronal plates {Eociclaris, ArchcBocidaris, &c.),
owing to the loose cuticle by which these plates were probably connected, much
as we find them in the modern Echinothurida3, it is not probable that we shall find whole
tests, as even in the recent types when they are dried the plates readily become dis-
connected, and we can form no idea of their shape when alive even from well-preser\'ed
alcoholic specimens. The abactinal system especially of these genera will very rarely be
well preserved, and we can only from analogy w4th the recent types form an idea of the
principal structural features of that part of the test. The plates of the actinal system
generally hold together more firmly, and from the similarity of its structure in such
genera as Archceocidaris, Pholidocidaris, and Lepidesthes, we can fairly assume that the
abactinal system corresponds in its general features with that of the Echinothuridse. As
far as I can judge from the specimens of PalseechinidEe in my possession which have
retained any part of the. actinal region of the test adjoining the actinostome, we find
that in Lepidocentrus there is no distinct line of division separating the coronal inter-
ambulacral plates from those belonging to the actinal membrane. The ambulacral
plates are continued in a remarkably well-preserved specimen from the lower Bur-
lington Limestone to the very teeth, and the same is the case with the interambulacral
plates ; neither the ambulacral nor the interambulacral plates show any line of demar-
cation such as we still find in the Cidaridae or such an indistinct one as exists in the
recent Echinothuridse, and as far as I could see in the specimen referred to, the test of
this genus was evidently composed of entirely similar plates, extending from the edge of
the actinostome, from the very membrane which was attached to the teeth to the
abactinal system, that is, the coronal plates extended from the actinostome without the
usual subdivision of the actinal membrane into ambulacral and interambulacral plates
which in this genus at least did not exist. In fact this genus corresponds exactly to a
stage of the Cidaridte in which the coronal plates as they are developed in that family
should be reduced to a minimum and replaced by the extension over the whole test of
imbricating plates, such as still exist prominently developed in the Cidaridse, and to a
more limited extent in some other Echinids, on the actinal membrane. In the Cidaridae
proper the junction of these plates with the coronal plates is still quite well marked,
while in the recent Echinothuridse the distinction between them is much less apparent.
As regards the actinal system of Melonites, from what we know of its structure from
Meek and Worthen, it apparently belonged to the same type as that of Lepidocentrus.

80 THE VOYAGE OF H.M.S. CHALLENGER.

The abactinal system of Melonites, on the contrary, from the drawings of Eoemer and of
Meek and Worthen, and of Palceechinus from those of Bailey, resembled far more that of
the Cidaridse proper than of the recent Echinothurid^. The ocular and genital plates are
comparatively large, in striking contrast to the adjoining minute ambulacral and inter-
ambulacral plates of the abactinal region of the test, forming a most distinct line of
division between the so-called coronal plates and the plates of the abactinal system.
This is somewhat remarkable, as the plates of the abactinal system are evidently, from
what we know of their appearance in young Echinids, developed comparatively later
than the coronal plates.

In Lepidocentrus and in ArcluBOcidaris, on the contrary, the plates of the abactinal
system resemble far more in their size and arrangement those of the abactinal system
of the recent Echinothuridse. In Lepidocentrus, for instance, the genital plates bear about
the same proportion to the plates of the anal system which we find in some of the recent
Echinothuridse, and there exists at the apical extremity of the coronal plates the same
difficulty in defining where the interambulacral plates terminate and the plates of the
apical system begin.

The existence of double pores in the apical system does not seem to indicate in the
Palseechinidas an abnormal structure among Echinoidea, Loven has already shown how in
the Arbaciadse the ocular pore is divided into two, and we must remember that in the
Spatangoids it is the contrary process which takes place, in the passage of double pores
to simple pores and then to double pores again between the actinostome and the
abactinal system. It seems to me to be merely the first indication of the subsequent
subdivision of the ambulacral pores to be traced among the Echinoidea which becomes so
universal among the regular Echinids, though it is transferred to a difi'erent part of the
poriferous zone, while in many Spatangoids it is limited to special portions of the
poriferous zone. In the Palseechinidse we may consider this the first indication probably
of the specialisation of any one of the ambulacral tentacles.

In a specimen of ArclicBOcidaris from the Keokuk Limestone showing the actinal side
of the test, the actinal plates immediately adjoining the actinostome are small imbricat-
ing plates, forming a somewhat indistinct line of demarcation with the true coronal plates
quite as clearly defined as in the recent Echinothuridse when compared to the primary
coronal plates siirmouuted by a single large primary tubercle as in Phorr)iosoma. The
ambulacral areas expand at the line of junction with the actinal membrane, and the rows
of pores are more distinct than in the poriferous zones of the corona. The interambu-
lacral plates are quite small ; but both the ambulacral and interambulacral plates ex-
tend to the very centre of the actinostome, where the actinal membrane is attached to the
outer edge of the teeth, There appear at the line of junction between the actinal plates
and the primary interambulacral plates interstices corresponding in position to those
which give passage to the gills in the recent Echinothuridse on each side of the poriferous

EEPORT ON THE ECHINOIDEA. 81

zone. The teeth are grooved as in the CidariclEe. The face of the pyramid of the jaw is
like that of the recent Echinothuridse, remarkable for the length of the teeth compared to
the height of the pyramid which is much less than is the case in the Echinidse. The
upper foramen of the pyramid is very small, the cheeks of the pyramids are deeply cut
by a triangular pit which forms a narrow edge, the outer side of the p}Tamid, and a well-
marked divitling wall with parallel edges between these two deep triangular depressions,
a modification of the structure of the pyramid, which as yet has not been seen in any of
the recent Echinidse. See also Mtiller's figure of the p)Tamid (Neue Echinod. d. Eifeler
Kalk., pi. iii. fig. 12). From the drawings of Trautschold of Archceocidaris rossica the
jaws of the genus resemble most closely those of Cidaris.

In the Cystocidaridas of Zittel {Echinocystites of Wy. Thomson and HaU) the jaws are
apparently very difi'erent from those of the Perischoechinida3, but they are not sufficiently
well known to compare them to those of other Echinoderms, though they would appear
from the drawings of Thomson to approach somewhat the mouthpieces of the Starfishes
and Ophiurans. The anal system of this group of Echinids is also excentric and not placed
at the apex of the test, where the other plates of the apical system are placed, — a
structural feature which was supposed to be characteristic only of the higher Ecliiuoidea,
the Spatan golds and Clypeastroids.

But by far the most embryonic of all Echinoidea, and the most interesting of the
Palaeozoic Sea-urchins, is the remarkable genus Bothriocidaris, in which, if the figures of
Schmidt ^ are correct, there is absolutely nothing to distinguish the plates of the actinal or
abactinal systems from those of the coronal plates proper in the ambulacral and interam-
bulacral areas. The ambulacra extend unbroken to the very plates which constitute the
edge of the actinal opening, and the interambulacral areas, which consist only of a single row
of plates, to the last row of plates surrounding the actinostome; and at the abactinal pole
the plates pass similarly without any change into the minute plates which must have
made up the anal system. As in all young Echinids the test also is made up of a small
number of coronal plates very uniform in size on both the ambulacral and interambulacral
zones, and diminishing only slightly in size towards the actinal and abactinal systems.

It seems quite evident from the above, and from the examination of the species of
Phormosoma and Asthenosoma collected by the Challenger, that the Palseechinidse are far
more closely allied to the recent Echinids than is usually supposed, and that we have in the
recent Echinothuridse structural features combining the characteristics of the normal
Desmosticha and of the Palajechinidse to such an extent that we are hardly justified in
regarding the Palaeechinidas as a subdivision of the Echinoidea equivalent to that of the
Cl3q5eastroids or Spatangoids.

In the Echinothuridse the pedicellarise in their general character are allied to those of
the Diadematidse, more specially to those of Astropyga. The long-headed long-stemmed^

1 Fr. Schmidt, Neue Bait. Sil. Petref., Mem. Acad. St Petersb., vii^. S^rie, xxi., pi. iii.

ZOOL. CHALL. EXP. PART IX. — 1881.) I H

82 THE VOYAGE OF H.M.S. CHALLENGER.

pedicellarise oi Asthenosoma grubii (PI. XLII. fig. 9) are very similar to those of Astropyga
(Revis. Echini, pi. xxiv. fig. 40). Of the globular-headed short-stemmed pedicellarige,
however, some difler totally from those of that group ; they are remarkable for the great
width of the base and of the upper extremities of the valves (PI. XLII. fig. 8, Asthenosoma
grubii). An interior and an exterior view of the valve of a similar pedicellaria of
Phormosoma luculentunn is given on Plate XLIV. figs. 25, 26, while, on the contrary, the
general structure of the long-headed pedicellarise of Phormosoma (PI. XLIV. figs. 19, 20,
Phormosoma tenue) closely resembles that of the same kind of pedicellarige in Centro-
stephanus (Revis. Echini, pi. xxiv. fig. 37), which are remarkable for the large open
meshwork structure of the central part of the valve (PI. XLIV. fig. 19, Phormosoma
temie, and PI. XLIV. fig. 36, Asthenosoma grubii). These vary greatly in size on
difierent parts of the test. This open reticulation is indicated in some of the Echinidae,
but is quite apparent in Pseudoboletia (PL XLIV. fig. 39).

The rods which support these pedicellarise are uniform in structure, they resemble the
rods of the pedicellariae of the Diadematidas ; they all have a slight constriction at the
head (PL XLIV. figs. 24, 28, 31, 32).

The EchinothuridsB also have (PL XLIV. fig. 34) short-stemmed globular pediceUariai,
resembling closely the abactinal pedicellariae of Aspidodiadema, but with coarser toothed
valvular edges. In addition to the remarkable long-pronged pedicellaria, figured by
Thomson as characteristic of the group, we have also remarkable bottle-shaped didactyle
pedicellarige, which are perhaps only modifications of the former (PL XLIV. figs. 21, 22,
Phormosoma tenue). They are at once distinguished by their regular reticulation, the
smaU size of the base, the broad fan-like expansion of the extremity, with the raised edges,
forming a deep triangular space at the upper end of the valve. This bottle-shaped pedi-
cellaria is only a modification of the ordinary type of pediceUarise in which the terminal
edge becomes raised to form a spoon-shaped valve. Another modification of it is formed
by the gigantic pedicellariae (PL XLIV. fig. 29, 29'), in which this cup-like cavity ex-
tends along the shank connecting it with the base (see also PL XLIII. fig. 1).

Asthenosoma.
Asthenosoma, Gnilje, 1867, Jahresb. der Schles. Ges. f. Vat. Cult.

*Asthenosoma grubii (Pis. XV., XVI., XVII., XXXVIII. figs. 1, 2, 4 ; PL XLII.
figs. 8, 9 ; PL XLIII. fig. 2 ; PL XLIV. figs. 32-36).

Asthenosoma Gnihei, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 200.

This is a pentagonal species with rounded corners (PL XV. fig. 1, PL XVI. fig. 1),
quite flattened when in alcohol (PL XV. fig. 2), with nearly vertical ambitus. Thickly
covered on the actinal side (PL XVI. fig. 1) with curved, hollow, primary radioles, which

REPORT ON THE ECHINOIDEA. 83

are short, flaring at the extremity, of a greenish colour, banded with white and brown,
or with violet brown transverse bands. These are of a very uniform size Ijoth over the
ambulacral and interambulacral areas of the actinal surface ; these curved spines extend
only to the edge of the ambitus, where they are replaced by short sharp spines (PI. XVI.
fig. 6a-c) covered by a muscular sheath, the extension of the cuticle of the test (PI. XVI.
figs. 2, 3, 4, 7-9) which in the shorter spines of the ambulacral area and of the median inter-
ambulacral zone (PI. XVI. figs. 7-9) forms a simple bag at its extremity, while in the
somewhat longer spines both of the edge of the ambulacral and of the interambula-
cral zones the sheath is constricted in several places according to the length of the spines
(PI. XVI. figs. 2-4), and is frequently banded with transverse patches of colour.

The whole test both on the actinal and abactinal sides carries short, sharp, slender
miliary spines (PL XVI. fig. 5), similar in structure to the longer spines of the abactinal
surface (PI. XVI. fig. 6.) This extension of the muscular sheath of the test over the
spine or a portion of the spine is characteristic of those spines of Echinothuridse in which,
owing to the absence of the milled ring proper as in other Echinids, the spines have retained
a more or less embryonic structure, and the muscular belt which, starting from the edge of
the scrobicular circle in Echinoids, generally terminates at the milled ring, extends in
some species of this family along the shaft of the spines either along a part of the shaft
or beyond its tip. This is a feature which is eminently characteristic of all young Echinids
which I have had occasion to examine. It reminds us also of the mode of growth of the
pedicellariae as a protuberance of the calcareous test covered by the general cuticle
covering the whole test, which eventually forces its way through this as also do the young
spines of Echinids, while in some of the Echinothuridse this sheath remains permanently
growing with the growth of the spines of the abactinal region. In other species of the
group {Asthenosoma coriaceum) this cuticle extends over the miliary tubercles with rudi-
mentary spines, leaving small pits which are more or less regularly arranged along the
coronal plates of the test. These spines difi"er materially from the primary spines of the
Perischoechinidte, which so far as is known are provided with a milled ring. The tubercles
also are both perforate, imperforate and not crenulate, difi"ering in this respect from those
of the Diadematidse proper. Towards the abactinal system and over the actinal system
the integument of the test is so thick as to conceal completely the sutures of the plates.
The elongated narrow actinal plates are remarkable (PI. XVII. fig. 4) for the arrangement
of the small tubercles they carry in regular horizontal rows concentric with the test ; the
pair of pores, the continuation of the poriferous zone, are placed in the centre of each
actinal plate.

In the abactinal system (PI. XVII. figs. 2, 3) the ocular and genital plates, with the
exception of the madreporic body, are indicated when denuded of spines by a large, some-
what indistinct plate, smooth towards the ocular or genital pore and covered with coarse
granulation at the anal edge. The anal system itself is covered by coarse distant granu-

84 THE VOYAGE OF H.M.S. CHALLENGER.

lation. The genital plate carrying the madreporic body is raised round the edges,
depressed in the centre, and extremely prominent. The anal opening is in the centre of
the anal system in the middle of a small ring formed by the rising of the integument of
the anal system. On the actinal side the large primaries of the interambulacral areas
are arranged in horizontal rows (PI. XYII. fig. 1), well separated by irregular groups of
secondaries and miliaries, the tuberculation is quite regular in size over the whole of the
interambulacral areas. In the ambulacral areas there are from two to three primary
tubercles on each plate, between the poriferous zone and the median line separated by one
or two miliaries or secondaries (PI. XVII. figs. 1, 6), with a horizontal line of secondaries
separating the rows of pores towards the outer edge of the plates and a cluster of the
smaller tubercles near the median angle of the ambulacral plates.

On the abactinal side the coronal plates become very gradually narrower and narrower
as they extend from the ambitus towards the abactinal system, and at the same time
the integument of the test separating the plates increases in width; the primary
tubercles diminish gradually in size and distinctness (PI. XVII. fig. 2) until towards the
abactinal system the tubercles are reduced to indistinct granules (PI. XVII. fig. 3), form-
ing more or less regularly curved narrow bands, with a re-entering curve towards the
median line, indicating the position of the interambulacral coronal plates (PI. XVII.
fig. 2).

The same takes place in the median ambulacral spaces, but as the tubercles are
originally smaller the change takes place nearer the ambitus. In the median ambulacral
line a bare band separates the tubercles of adjoining plates, and a similar bare band
separates the outer row of pores from the interambulacral plates. The poriferous zone is
broad at the ambitus : it is broader than the corresponding part of the ambulacral plate.
It diminishes very gradually in width towards the abactinal system, and forms on the
abactinal side of the test three vertical rows of pairs of pores (PI. XVII. fig. 2). The two
inner rows are placed quite close together, the outer well separated from the two inner
rows (PL XVII. fig. 5) and further distinguished by a vertical row of small secondary
tubercles running between it and the two rows. On the actinal side these three rows
can be distinguished only near the ambitus (PI. XVII. fig. 1) ; they soon become ex-
tremely irregular by the gradual narrowing of the poriferous zone, so that about half-way
between the ambitus and the actinal edge the three rows are united (PI. XVII. fig. 6), the
pairs of pores having become contiguous and forming a slightly oblique row of three pairs
of pores.

This species is probably the same which Grube first described as Asthenosoma variuin.
His original description was, however, so short that Echinologists did not recognise the
importance of the discovery of the genus, and Thomson himself when he first mentions
Calveria in the Depths of the Sea could not suspect its identity with Astheno-
soma, as Calveria does not possess the peculiar sheathed spines so characteristic of

REPORT ON THE ECHINOIDEA. 85

Asthenosoma varium, aucl as Grube said nothing of the lajjping of the coronal plates.
It was only on seeing the original specimen at Breslau that I recognised the identity
of the genera. At that time (1870) Professor Grube was kind enough to give me a few
spines of this species, and on comparing them subsequently with those of the species
called here Asthenosoma gruhii, there seemed to exist sufficient difierences in. them, and
more especially in the greater size of the primary tubercles of the actiual surface (of
which Professor Grube had sent me a cbawing), to warrant me in separating these species
for the present. Grube's specimen is much smaller than the specimens collected by the
Challenger, so that it may yet turn out that the diflferences existing between our
specimens are merely due to age. The perforation of the tubercles of the abactinal
surface is so small that it could not be represented on the natural size drawing of
Plate XVII. fig. 2. It was, however, unfortunately omitted on the figure of the actinal
side (PL XVII. fig. 1). It is shown on the enlarged figures (PL XVII. figs. 5, 6). The
locality of Grube's specimen was not definitely known ; as it came from Salmin, who had
at the time of its pui'chase extensive dealings with the Philippine Islands, it undoubt-
edly came from the Eastern Seas of China or that neighbourhood. The specimens of the
Challenger aU coming from such a shallow depth as ten fathoms it is quite possible that
this species may be a littoral one, or at any rate that it lives in comparatively shallow
water. In the species of Asthenosoma, judging from the single smaller specimen of
Asthenosoma gruhii and from those of Asthenosoma j^ellucidum, the changes due to growth
do not seem to be as marked as in Phormosoma. The smallest specimen oi Asthenosoma
gruhii (measuring 115 mm.) already showed the principal specific characters of the adult
(183 mm. in diameter), the only important difi"erences being such as are readily accounted
for by the size of the specimens. The few spines left on the abactinal surface of this
smaller specimen show that the peculiar sheathed spines so characteristic of this species
already exist in specimens of a comparatively small size.
Samboangan ; 10 fathoms.

* Asthenosoma pellucidum{^\.XS[lll. figs. 1-6; PL XVIII.'' figs. 14-17; PL XIX.
figs. 1-6 ; PL XXXVIII. fig. 6 ; PL XL. figs. 39-42).

Asthenosoma pellucida} A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 200.

In this species of Asthenosoma the primary tubercles form a prominent vertical row
in the interambulacral area adjoining the poriferous zone, the tubercles being largest
near the ambitus both above and below the ambitus (PL XVIII. figs. 4, 5 ; PL XIX.
figs. 4, 5). In the ambulacral areas there are only secondary tubercles, three or four of
which on the abactinal side are somewhat larger than the others near the ambitus. From
the large primary interambulacral tubercles extends a more or less regular horizontal row

' The new species of Asthaiosoma and of Phormosoma were inadvertently published with feminine terminations.
This error was not noticed in time to correct the lettering of the plates.

86 THE VOYAGE OF H.M.S. CHALLENGEK.

of secondary and miliary tubercles, occupying the middle region of each plate, and
extending to the median line (PL XVIII. figs. 4, 5). On the ambulacral plates the
secondaries are distant and more irregularly arranged than on the interambulacral plates
(PL XVIII. fig. 1, 2, 4, 5). The coronal plates vary in colour from greenish to light
violet brown, the intervening bare spaces of the membrane of the test are of a milky
colour.

The suckers of the tentacles are tipped with orange on the actinal side. The test of this
species is remarkably thin, even in the largest specimen (64 mm. in diameter), the cal-
careous plates do not give to the test any degree of solidity. In alcohol the general outHne
of the test is angular with rounded corners, and when seen in profile the edges of the test
are somewhat swollen, the test sinking below the level of the ambitus between it and the
actinostome, and also between the ambitus and the abactinal system. There are three
kinds of pedicellarise found upon the test resembling those of the test of Phormosoma.
The pointed suckers of the abactinal side are large, and commence close to the ambitus.
In Plate XVIII. fig. 6, the abactinal system has accidently been drawn out of line; the axis
passing through the madreporic body should be on the left to have it correspond with the
other figures of the abactinal system on the same plate. The larger primary spines,
especially those near the ambitus on the actinal surface, resemble somewhat the curved
trumpet-shaped hollow spines of Asthenosoma grubii; they are, however, longer, more
slender, and of a lighter colour and transversely l^anded with vermilion, the other
secondary and miliary spines of both areas are shorter, sharp pointed, and only a few of
the primary spines of the abactinal surface near the ambitus are trumpet-shaped ; the
otliers resemble the secondary spines, but are larger and comparatively stouter, and are
more or less irregularly banded with carmine.

In young specimens (PL XVIII. figs. 1,2; PL XVIII." figs. 14, 15) the vertical row of
primary tubercles adjoining the poriferous zone is not as weU marked as in the older
specimens, nor are the horizontal rows of secondaries and miliaries well defined. In the
smallest specimens collected (PL XIX. fig. 1-3) the spines are transversely banded with
broad carmine rings. In young specimens the primary spines are proportionally longer,
but as in older specimens of this species they are cylindrical, scarcely tapering towards
the tip. The secondary and miliary spines are fine, sharp pointed and uniformly tapering.
The integument of the abactinal system nearly conceals the calcareous plates irregularly
arranged round the anal opening, and also encroaches considerably on the outer edges of
the plates of the genital ring. The ocular plates are pentagonal, horizontally elongate ;
the genital plates (PL XVIII. fig. 6) are pear-shaped, pointed towards the median inter-
ambulacral line. The genital and ocular plates carry two or three secondary tubercles
near the anal edge.

In somewhat younger specimens the abactinal system is marked for the greater uni-
formity in the size of the genital and ocular plates (PL XVIII. fig. 3).

REPORT ON THE ECHINOIDEA, 87

Young specimens of Asthenosoma pellucidum (PI. XVIII. figs. 1, 2) show how close is
the relationship between the genera Phormosoma and Asthenosoma in spite of the
apparently great structural differences existing between the adult of such species as
Asthenosonui grubii and Phormosoma luculentnm. It is mainly from the comparatively
larger number of coronal plates in the former genus that the young of the two genera
can Ije satisfactorily distinguished, the other characteristic features, the lapping of the
plates appearing only in larger specimens. There is nothing in the growth of
Asthenosoma corresponding to the splitting up into separate plates of the primary
coronal plates so characteristic of Phormosoma when seen from the interior of the test
(PI. XVIII.» figs. 4, 5, 7, 8).

Each primary plate of Phormosoma, consists of a number of plates most irregular
in shape (PI. XVIII. " figs. 4, 7), held together quite loosely by the inner integu-
ment of the test, the joints of the plates are often foliated, and the centre is
sti'engthened by a thicker deposition of calcareous matter forming a sort of button ex-
tending beyond the level of the plate towards the interior of the test. This thickening
which corresponds to the lower side of one of the primary tubercles I have described
more in detail in the description of Phormosoma tenue. This species difiers from both
Asthenosoma hystrix and Asthenosoma fenestratum in having a smaller number of coronal
plates, these are consquently higher ; in Asthenosoma jfellucidum this difierence becomes
very striking in the height of the plates of the ambulacral areas. The open spaces between
the coronal plates are largest on the actinal surface where they appear first in the
younger stages and gradually extend to the abactinal surface with increasing size. In a
small specimen measuring 36 mm. in diameter, the coronal interstices are limited to a
narrow line parallel to the edge of the plates. In specimens measuring 44 mm. the coronal
interstices assume already the elongated form represented in Plate XVIII. fig. 4. In
the smallest specimen of this species examined, measuring 36 mm. in diameter, the gills
are reduced to a small forked appendage protruding between the edge of the coronal
plates and the mailed actinal memlirane. In the older specimens of Asthenosoma
pellucidum there is a decided thickening of the epidermis of the test, which tends gradually
to obliterate the outlines of the coronal plates. We have this character developed to a great
degree in Asthenosoma coriaceum. Unfortunately, the largest specimens oi Asthenosoma
pellucidum are so much smaller than the smallest Asthenosoma coriaceum or the single
specimen of Asthenosoma tessellatum, that I am unable to satisfy myself that the present
species (Asthenosoma pellucidum) may not be the young of Asthenosoma coriaceum. In
the only species of the group of which the Challenger collected a complete series (Phor-
mosoma tenue) there was little difficulty in recognising the young as belonging to the
adult, the same was the case for Phormosoma luculentum. The changes in the coronal
plates are not as great, and the arrangement of the pores does not seem to vary as much
in Phormosoma as in Asthenosoma.

88 THE VOYAGE OF H.M.S. CHALLENGER.

OfFCebu, 100 fathoms.

Station 192. September 26, 1874. Lat. 5° 42' S.; loDg. 132° 25' E.; 129 fathoms ;
mud.

'''Asthenosoma coriaceum (PI. XVIL* figs. 5-7).

Asthenosoma coriacea, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 201.
This is a large species allied to Asthenosoma gruhii in having an extremely thick
leathery cuticle, but readily distinguished from it by the greater height of the coronal
plates ; in specimens of the same size there are more than twice as many plates as on the
abactinal surface of Asthenosoma gruhii. The plates of the abactinal surface carry but
fcAV primary spines limited to the neighbourhood of the ambitus ; while on the actinal
surface the plates bear over a great part of the floor, long comparatively stout hollow
primary spines but slightly curved and very slightly flaring, resembling more nearly the
primary actinal sj)ines of Phormosoma than the characteristic flaring trumpet-shaped
spines of Asthenosoma. The abactinal surftice is nearly bare; it carries but few primaries
near the ambitus, and small, short, sharp secondaries and miliaries confined mainly to
the outer edges of the ambuhicral and interambulacral zones. With this exception the
general arrangement of the tubercles both in the ambulacral and interambulacral areas
resembles that of Asthenosoma tessellatum ; the coronal plates are also more prominently
pitted (PL XVIL* figs. 6, 7), and towards the abactinal system, where the plates are very
narrow, their presence is indicated by angular rows of pits following the course of the
coronal plates (PL XVII. * fig. 7). It is quite possible, as I have stated in the pre-
liminary Report of the Challenger Echini (Proc. Am. Acad., 1879, vol. xiv. p. 201), that
this may be the adult of Asthenosoma tessellatum, yet from the identity abeady clearly
apparent in specimens difiering far more in size in other species of the genus, both in
Asthenosoma jieUucidum and in Asthenosoma gruhii, I am inclined to keep it distinct
for the present, as in the sjDecimens of Asthenosoma tessellatum, measuring 140 mm.,
and in one of Asthenosoma coriaceum, 220 mm. in diameter, there is only a diflerence of
a few plates in the number of coronal plates, while we might expect, judging from their
size, a greater difierence in the number.

Station 173. July 24, 1874. Lat. 19° 10' S. ; long. 179° 40' E. ; 315 to 310
fathoms ; coral.

Station 172. July 22, 1874. Ofi" Nukualofa, Tougatabu ; 18 and 240 fathoms;
coral.

''' Asthenosoma tessellatum (PL XII.^ figs. 14, 15; PL XIX.^ fig. 1; PI. XIX.").

Asthenosoma tessellata, A. Agassiz, 1879, Proc. Am. Acad., vol xiv. p. 201.
Only a single specimen of this species was collected ; it is of a dark chocolate colour.

REPORT ON THE ECHINOIDEA. 89

with the narrow coronal plates of a lighter violet tint forming a most regular pavement on
the actiiial and abactinal surfaces of the test. The interstices between the coronal plates
are even more developed in this species than in AstJienosoma fenestratum, extending
as they do from the edge of the poriferous zone nearly to the extremity of the coronal plate
in the median interambulacral space where they lap. The lapping of the plates is very
marked in this species, even when seen from the outside (PL XIX.'' fig. 2). The lapping
of the ambulacral plates is not so well marked except in the older plates towards the
ambitus on the abactinal surface. The encroachment of the interambulacral plates on
the outer edge of the ambulacral plates is also shown from the exterior, the wnngs of the
extremities of the plates covering the ends of the corresponding plates of adjoining
areas, as has been abeady noticed by Thomson in Asthenosoma hystrix. On the actinal
side this lapping is not well seen, the plates appearing externally to abut regularly
both in the ambulacral and interambulacral areas (PI. XIX. "^ fig. 1) as in the Desmosticha
proper ; but an examination of the interior of the test shows the lapping of both areas
to be as prominent as in the figure of Asthenosoma hystnx given by Thomson (Porcup.
Echin., Trans. Roy. Soc, 1874, pi. Ixv. fig. 2). The primary spines of this species are few
in number (PL XIX." fig. 1, PL XIX.^ figs. 1, 2), and are limited to a few plates near the
ambitus on the actinal and abactinal surfaces, in addition to the single prominent row
extending from the actinostome a short distance over the ambitus, to the abactinal region
(PL XIL^figs. 14, 15, PL XIX.^ fig. 1, PL XIX.^ fig. 2) along the outer edge of the inter-
ambulacral zone next to the poriferous zone. The other spines, secondary and miliary, are
also few in number, and slender, and are irregularly arranged on the ambulacral and inter-
ambulacral plates ; there are a number of miliary tubercles forcing then- way through the
cuticle, which appear as pits (PL XII.'' figs. 14, 15). The gUls in this species are large
and prominent (PL XIX." fig. 1). Judging from the single alcoholic specimen the
ambulacral tentacles of this species must have been of an unusual size (PL XIX." fig. 1,
PL XIX.'^), especially near the ambitus l^oth on the actinal and abactinal surfaces. The
sucking disks are not large even on the actinal sm'face, and on the abactinal surface they
soon become, beyond the ambitus, more slender and pointed (PL XIX.'' fig. 4). The al^ac-
tinal system is comparatively smaller than in Asthenosoma coriaceum, and diflfers mainly
in the position of the genital openings which are relatively more distant from the centre
than in Asthenosoma coriaceum ; the tuberculation of the anal system is also coarser in
the latter species and is covered by larger plates. Compare Plate XIX.'' fig. 3, and Plate
XVII.^ fig. 5.

Station 204. November 2, 1874. Lat. 12° 43' N., long. 122' 10' E.; 100 fathoms
and 115 fathoms ; mud.

* Asthenosotna gracile, n.sp. (PL XVII.* figs. 1-4).

This species resembles Asthenosoma hystrix in having comparatively narrow elongated

(ZOOL. CHALL. EXP. — PART I.X. 1881) I 12

90 THE VOYAGE OF H.M.S. CHALLENGER.

coronal plates, while in its general appearance, its colouring, and the sti'ucture of the
spines it approaches Astlienosoma tenue. Notmthstanding that there is but a single
adult specimen of this species, I have no hesitation in describing it as distinct. The
colour of the test in alcohol is yellowish, the spines of the same tint, Tvdth large violet
patches on the actinal surface. The special characters of Asthenoso'ma gracile are the
two irregular rows of small primary tubercles in the ambulacral area extending about
half-way to the abactinal system from the ambitus, and in the interambulacral areas the
coronal plates near the ambitus carrpng from three to four primary tubercles (PI. XVII. *
fig. 4) ; while further towards the abactinal region the number of large tubercles is gradually
reduced to one on every other plate. There are secondaries or miliaries loosely and
irregularly arranged on the narrow plates ; the interstices between the coronal plates of
both areas are much as they are in Asthenosoma hystrix, judging from the width of the
connecting membrane. On the actinal side the primary tubercles of the interambulacral
area form, as they do in Asthenosoma hystrix, two principal vertical rows extending from
the ambitus to the actinostome, the one adjoining the poriferous zone, the other in the
median line; the rest of the plate is occupied by from four to seven small secondaries
with a few miliaries arranged in irregular horizontal rows (PI. XVII.'' fig. 3). In the
ambulacral area the primary tubercles are small, arranged in an iiTcgular vertical row
nearer the median line, with secondaries and miliaries placed much as they are in the
interambulacral zone. The actinostome of the specimen figured natural size on
Plate XVII.'' fig. 1, measured 26 mm. in diameter, the abactinal system 16 mm. The
primary spines are short, slender, blunt at the extremity, diff"ering mainly in size from
the shorter and sharper secondaries and miliaries. On the actinal surface, however, the
spines of the actinal membrane are slightly curved and spathiform, and a few of the
primary spines are also curved, trumpet-shaped, flaring at the extremity. The abactinal
system (PL XVII." fig. 2) diffei's from that of Asthenosoma pellucidmn in having large
pointed genital plates extending into the median interambulacral s^aace and comparatively
small ocular plates, while the aljactinal system of Asthenosoma jyellucidum is remarkable
for the uniform size of the ocular and genital plates (PI. XVIII. fig. 6).

Small specimens of Asthenosoma from Stations 184 and 219 are referred to this
species with considerable doubt. The largest of these young specimens differs more from
Asthenosoma gracile (figured on PI. XVII.'') than young specimens of corresponding
size differ from Asthenosoma j^^T-lucidutn. The arrangement of the tubercles on the
abactinal surface (PI. XII.* fig. 5) in a specimen measuring 24 mm. is such as would be
found in a species of Asthenosoma at any rate closely aUied to Astlienosoma gracile,
although the appearance of the actinal surface is more like that of a Phormosoma than
that of an Asthenosoma, and the size and position of the ocular plates (PL XIL* fig. 5)
is different from that of the oldest Asthenosoma gracile figured on Plate XVII."

Dr Studer (Monatsber. Berlin Akad., 1876, p. 464) has described from Great Harbour,

REPORT ON THE ECHINOIDEA. 91

New Britain, a very remarkable Astroijyga which he calls Astropyga elastica; unfortunately
it is as yet not figured, but, judging from his description, it is closely allied both to
Asthenosoma and to Astropyga ; the coronal plates of the tests resembling in structure
those of Asthenosoma, whUe the facies of the species and the arrangement of the spines
recall Astropyga radiata. This species was not collected by the Challenger, but some
of the young specimens of Echinothuridae which have been provisionally named may
ultimately prove to belong to this ty^a ; perhaps the young I have temporarily referred
to Asthenosoma gracile from Stations 184 and 219. The differences to be observed in the
structure of the test and arrangement of the spines in the figures of the young specimens
called Asthenosoma gracile and the normal Asthenosoma and Phormosoma are quite
striking when we compare them with the figm'es of an undoubted young Asthenosoma
{A. pellucidum) and of a genuine Phormosoma {P. tenue).

Station 219. March 10, 1875. Lat. 1' 50' S., long. 146° 42' E.; 150 fathoms ; mud.

Station 200. October 23, 1874. Lat. 6° 48' N., long. 122' 25' E. ; 255 fathoms ;
mud.

Station 184. August 29, 1874. Lat. 12° 8' S., long. 145° 10' E.; 1400 fathoms;
bottom temj)erature, 1"8° C. ; grey ooze.

Station 169. July 10, 1874. Lat. 37° 34' S., long. 179° 22' E. ; 700 fathoms;
bottom temperature, 4 "2° C. ; grey ooze.

Phormosoma.

Phormosoma, Wy. Thorn., 1874, Echin. Porcup., Trans. Eoy. Soc, vol. clxiv., part 2, p. 732.

*Phormosoma tenue (Pis. XIII., XIV., XVII.^ fig. 8 ; PL XVIII. figs. 7-9 ; PL
XVIII.'' figs. 1-13; Pis. XVIII.^ XVIII.^ figs. 5-9; PL XIX. figs. 7-9; PL XIX."
fig. 2 ; PL XXXVIII. fig. 5 ; PL XXXIX. fig. 9 ; PL XL. figs. 29, 30 ; PL XLII. fig. 7 ; PL
XLIV. figs. 19-24).

Phormosoma tenuis, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 202.

In a large specimen (PL XIII. fig. 1) measuring 133 mm. in diameter, the primary
tubercles (when seen from the aljactinal side) are small and irregularly distributed over
the whole of the abactinal surface both in the ambulacral and interambulacral areas ; these
tubercles carry slender, hollow, cylindrical spines tapering but little at the extremity, the
intertubercular space is occupied by a few distant miliaries and secondaries carrying small
sharp spines. Immediately on the edge of the test are seen a few of the large primary
tul^ercles which on the actinal surface occupy the outer edge of the test and are arranged
in vertical rows, diminishing very rapidly in size as they approach the actinostome
(PL XIX.* fig. 2). The spines of these large tubercles are cylindrical, hollow, and a few
of them surmounted by a short conical hoof. These large spines are far less prominent
than in such species of the genus as Phormosoma hoplacantha, Phormosoma lucidentum,

92 THE VOYAGE OF H.M.S. CHALLENGER.

and the like. The general colour of the test of this species is yellowish-grey, the sutui-al
lines of the coronal plates are distinct, and the poriferous zone and ambulacra! system
well defined from the ambitus to the actinostome, the amljulacral tentacles prominent,
swollen, tapering, and tipped with a slight sucker, while they become pointed on the
abactinal system and are much less prominent. The miliaries and secondaries of the
actinal surface are more numerous than upon the abactinal surface. In a smaller
specimen measuring not more than 91 mm. in diameter the difference between the tuber-
culation of the actinal and abactinal surfaces is not so marked (PL XIX. figs. 7, 8).
The scrobicular area, it is true, is already covered by the swollen integument attached
to the base of the spine, but there is no such striking difference as in the adult ; the greater
prominence of the ambulacra! zone of the actinal surface, however, already exists (PI. XIX.
fig. 8). The sutures of the plates are also better defined, and the coronal plates are not
yet liroken up into secondary plates. The line of demarcation between the actinal mem-
brane and the coronal plates is not so well defined, and the same is the case as to the line
of demarcation between the aliactinal system and the coronal plates adjoining the anal
system. There is no material difference in the arrangement of the plates or of the pores,
but the coronal plates of young specunens overlap but little, and the genital as well as the
ocular plates (PI. XVIII. fig. 9) are far more distinct than in the adult where the large
anal plates have forced their way between them.

Thomson was the first to call attention to the peculiar structure and arrangement of
the internal organs of this group ;^ the observations here recorded will supplement the
earlier ones of Thomson.

The genital organs are narrow ; they branch slightly, forming small clusters on each
side of a long median tube. They extend not more than half-way from the abactinal
system towards the edge of the test (PI. XIV. fig. 1). The main ambulacral tube is large
and specially prominent on the actinal side (PI. XIV. fig. 2) where the ambulacral pores
are closely crowded together, and the lateral tubes extending to them from the main tubes
form, as has l)een noted by Thomson, a series of parallel tubes across the median ambula-
cral plates (PI. XIV. figs. 2a, a'). These lateral tubes are finer and more distant in the
abactinal part of the test (PL XVIII.'' figs. 10, 11) forming delicate lines merely, not
visible without being magnified (PL XIV. fig. 1). The general arrangement of the
alimentary canal reminds us of that of the Diadematidse (see plate xxvii., Revis. Echini) ;
but in addition we find that the mesenteries attaching it to the test form in this family
(as has already been noticed by WjrvUle Thomson) a series of partitions in the shape of
large open horse shoes, extending over the ambulacral systems and confining the loops of
the alimentary canal to the interambulacral spaces (PL XIV. fig. 2). The extremities
and edges of these mesenteries are attached to the actinal and abactinal floors by ex-
ceedingly fine threads. The whole system of horse shoes thus forms a sort of pouch, ■^dth

1 Echiuoidea of the Porcupine Expedition, Trans. Roy. Soc, vol. clxiv. part 2, plate xlvi.

REPORT ON THE ECHINOIDEA. 93

five openings to the interamljiilacral spaces ; this pouch confines the ahmentaiy canal
within a proportionally small area of the test, no single fold of the alimentary canal ex-
tending beyond half-way from the actinostome to the edge of the test (PI. XIV. fig. 2).

The alimentary canal coming out from the jaws into the left anterior interambulacral
area (seen from the inside) runs just inside of the auricles, along the edge of the principal
plates to the right aml^ulacral space, where it turns back again, runs outside the auricles
completely round the actinostome to the right interambulacral space where it makes
another turn, and then, forming great loops in extending outwards in the interambulacral
spaces and shorter loops turned towards the actinostome in the ambulacral spaces, it
passes to the anal opening in the right anterior interambulacral space (PL XIV. fig. 2).

Plate XII. fig. 2, shows for Fhormosoma hoplacantha the position of the alimentary
canal as it starts from the jaws and runs just inside of the auricles ; it also shows the
mode of attachment of the mesenteries of the horse-shoe pouch to the abactiual system,
and the complete separation by this returning fold of the space in which the ovaries are
placed from the poriferous zone, as is seen in PL XIV. fig. 2 on the actinal side.

In this species of Phormosoma, as in the genus so far as has been observed, the plates
overlap in the opposite direction in the ambulacral and interambulacral spaces.

In the interior view of the test of Phormosoma temie (Pis. XIV., XVIII." figs.
1-13) the lapping of the whole edge of the plate, so characteristic of Phormosoma, is
well seen, the double line round each coronal plate showing the extent of the overlapping,
and the double line along the outer edge of the ambulacral zone shows the extent of the
lateral covering of the edge of the ambulacral area. In Asthenosoma. it is only the ex-
tremities of the ambulacral and interambulacral plates which lap along the median hue
and along the line of junction of the two areas, whUe hi Phormosoma this lapping extends
along the whole horizontal edge of the plate in both areas. In Asthenosoma, viewed from
the outside, the outer and inner lower edges of the coronal plates pass under the upper
edges of the preceding plate in the interaml^ulacral areas, while in the ambulacral area it
is the upper edges of the plates which pass under the lower edges of the succeeding
plates counting from the actinostome.

In the actinal system seen from the interior (PL XVIII.'^ fig. 6) the ambidacral tubes
pass under the auricles to plates immediately adjoining the teeth, where they are con-
nected by a circular tube (PL XVIII.'^ fig. 4). The ampuUae are large, and the tubes
leading to them distinct. A series of mesenteries separating the ambulacral from the
interambulacral system, extend from the base of the auricles to the actinal edge of the
actinal system.

The structure of the actinal and abactinal systems in this family shows most satisfac-
torily the embryonic characters of the family and the intimate connection the plates
composing these two systems have, the one with the base of the actinal extremity of the
ambulacral system and the other with the abactinal plates of the interambulacral system.

94 THE VOYAGE OF H.M.S. CHALLENGER. •

We find here no such sharp line of demarcation as exists in other regular Echinids between
the abactinal system (composed of the anal system and the plates forming the genital
ring) and the abactinal extremity of the coronal plates ; the abactinal system in nearly
all the groups except the Diadematidae being in the adult set in, as it were, independently
within the upper extremity of the coronal plates. In some of the Diadematidse we find
something analogous to the structure of the abactinal system in this group. In Echino-
thrix, Diadema and Astropyga the long-pointed triangular genital plates, encroaching far
into the median interambulacral line and separating the opposing abactinal plates of the
interambulacral areas, form the beginning of a closer connection between the outer plates
of the anal system and the new plates of the interambulacral area. This connection is so
close that it is well-nigh impossible to state with certainty whether the new interambu-
lacral plates formed at the abactinal extremity are derived from the splitting up of the
upper interambulacral plates or of the outer plates of the anal system (see PI. XVIII.''
figs. 1, 2). In both these figures the anal plates intercalated between the genital and
ocular plates cannot be distinguished from the adjoining interambulacral plates. This
intercalation is not so apparent in the younger stage figured on Plate XVIII. fig. 9.

In the same way at the junction of the actinal plates with those of the ambulacral
system the continuity is unbroken (PI. XVIII.'' fig. 3 ; PL XII. fig. 4), and although there
are a few additional plates formed at the line of junction of the two systems, yet at a very
early stage the number of plates characteristic of the actinal system are formed, and the
growth of the test merely separates the suckers piercing the actinal membrane ; although
the additional plates of the actinal membrane are formed, as I have shown, from the sepa-
ration of the last small intercalated ambulacral plate and its suljsequent lateral growth.

Neither in Asthenosoma (PI. XVII. fig. 1) nor in Phormosoma (PL XII. figs. 3, 4;
PL XVIII. fig. 8 ; PL XVIII.'' fig. 3) are there any prominent actinal cuts for the passage
of the gills ; there are slight indentations between the plates at the actinal junction
of the ambulacral and interambulacral systems, and the gills appear in the youngest
stages I have examined.

The plates covering the actinal membrane are, with the exception of a few in the
outer central part opposite the median interambulacral line, all ambulacral plates occujDy-
ing the whole of the membrane (PL XVII. fig. 4 ; PL XVIII.'' fig. 3). The arrangement
of the actinal plates in this family, and their close structural connection with the plates
of the ambulacral system, are a further step in showing the gradual modifications which
the actinal ambulacral plates have undergone, so as to form gradually an imbricating
actinal meml^rane such as is characteristic of the Cidarid^, passing into an actinal
membrane in which we find, as in the majority of the regular Echinids, only ten buccal
plates, the rest of the membrane being more or less strengthened by irregularly arranged
imbricating plates which may form a thick close pavement, as in some species of
Echinus and the like, or else an entirely bare membrane with a few scattered calcareous

REPORT OX THE ECHINOIDEA. 95

spicules as in the bulk of the Diadematidse. In fact the Ecliinothuridse strongly recall to
us the embryonic stages of our regular Echioids {Strongylocentrotus and Arbacia) in which
the distinction between the coronal plates and the actinal and abactinal systems does not
exist, and in which the whole test is made up of plates of similar structure. The Echino-
thurid^ are somewhat more differentiated than the Perischoechinidse, in which the
coronal plates themselves are stUl very numerous and not reduced to the typical number
of two j)lates for the interambulacral system, as in all the Echinoidea known at the present
period; but even in the Echinothuridse we stUl have a trace of this abnormal character of
the Perischoechinidse, of having a number of rows of plates in the interambulacral system.

Some of the species of the genus Phormosoma, in which the test is most flexible, such
as Phormosoma tenue, show traces of an irregular sul^division of the coronal plates both
on the actinal and abactinal sides (PL XIII. fig. 1, PL XIV. figs. 1, 2, PL XIX.^ fig. 2).
Diagonal or transverse lines are seen to run from one plate to the next, so as to sub-
divide the primary coronal interambulacral plate into two or three, and sometimes four
or five secondary plates ; each one of these secondary plates corresponding usually to a
primary or secondar}^ tubercle. This breaking up of the primary plates, of course, gives
to the test a much greater mobility than it had before in spite of the extreme tenuity of the
test (PL XVIII.^ figs. 4, 5, 7, 8). These secondary plates, although extremely thin round
the edges, are strengthened in the centre by a deposition of carbonate of lime forming a
circular button in the centre (PL XVIII.'' fig. 4), to strengthen that part of the plate
which carries the primary tubercles and spines. This splitting up of the coronal plates
into plates corresponding each to a primary tubercle exists also to a certain extent on
the actinal surface of Astropyga, though it has not to my knowledge been noticed before.
The thickness of the inner and outer fold of the cuticle of the test forms lines more or less
coincident with the secondary plates of the interambulacral areas (PL XIV. figs. 1,2;
PL XVIII." fig. 7). This gives us, I think, a natural explanation of the structm*e of the
coronal interambulacral areas of the PerischoechiQidse, only in this group the splitting up
of the primary interamljulacral coronal plates was quite regular, and the lines of sutures
are regularly placed as in the amljulacral system. It is remarkal^le that in the Spatan-
goids, the Clypeastroids, and all the higher Petalosticha, the arrangement of the plates of
the ambulacral system should have remained comparatively simple as well as in the most
embryonic group of the Desmosticha, the Cidaridae and Salenidse, while La the Perischoe-
chinidse, the Echinothuridse, and by far the larger number of the Desmosticha, the
arrangement of the plates of the ambulacral system is quite complicated, and the number
of rows of plates across the ambulacral areas greater than that of the interambulacral
areas (which are, of course, limited to two in the bulk of the recent Desmosticha).

Grube and Thomson have already called attention to the similarity in the structure of the
teeth of the Echinothuridse and Diadematidae. Thomson has figured the teeth of Phormo-
soma placenta (Porcupine Echinids, Trans. Roy. Soc, 1874, pi. Ixiii. figs 9, 9«), and I have

96 THE VOYAGE OF H.M.S. CHALLENGER.

figured the teeth of another type of Phorniosoma {Phormosoma teniie) on PL XVIII.'',
these teeth differ consideraljly in the size of the foramen of the pyramids, and the shape
and prominence of the median ridge. The jaws of Phormosoma temie are proportionally
more solid than those of Phormosoyim placenta, and also broader in proportion to their
height.

The plates of the actinal membrane imbricate, as do those of the test, away from the
actinostome. In the abactinal system the membrane is only partly covered by the plates,
leaving a marked reticulation between them ; the tubercles of these plates are very
indistinctly crenulate and surrounded by a broad smooth areolar space. The whole
surface of the abactinal part of the test is dotted by delicate pigment (violet) spots. In
the ambulacral areas these spots are closely packed round the openings for the passage of
the suckers, forming a delicate ring at the base ; the suckers near the abactinal region
become pointed (PL XVIII." fig. 12). Suckers are present on the actinal region
somewhat beyond the ambitus (PL XVIII." fig. 13). On the abactinal surface of
a specimen measuring 168 mm. in diameter (PL XVIII. fig. 7), the primary tubercles are
arranged on the interambulacral area in two irregular vertical rows. Towards the
ambitus the tubercles are more numerous, arranged in thi-ee or four irregular rows. The
secondary tubercles are irregularly arranged, increasing in number towards the edge of
the test. In the ambulacral area there are two irregular vertical rows of primary tubercles,
and, adjoining the amlxilacral pores, on the interior edge, secondary tubercles are arranged
in an irregular vertical row ; these, as well as the primary tubercles, become more numerous
towards the edge of the test. The primary tubercles of the abactinal region are smaller
than the large primary tul^ercles which cover the actinal region, being really intermediate
in size between them and the secondary tubercles. The pedicellaria3 of the abactinal
surface of the test are scattered over the whole surface of the test. They are, however,
more numerous in the amljulacral area, and in the adjoining part of the interambulacral
area. The pedicellarias are long stemmed with a small head articulating with a second
stem, from twice to three times the length of the head (PL XVIII.'' fig. 11). A second
kind of pedicellaria with an inverted conical head, and a comparatively stouter joint
articulating upon a long stem occurs not unfi'equently upon this surface of the test (PL
XVIII.'' fig. 13). They resemble those figured by Thomson for Calveria hystrix.

Close to the ambitus on the actinal side the primary tubercles take a great develop-
ment, the scrobicular areas of the tubercles of the interambidacral and the single one of
the ambulacral area occupying the greater part of a plate, but except on three or four of
these large primary plates the other tubercles near the actinostome soon assume the
proportions of those of the abactinal surface (PL XIX.* fig. 2), but they are placed close
together.

The secondaries, miliaries, and pedicellarise, are also far more numerous on the actinal
side of the test, and we find there a third kind of pedicellaria with a shorter articulation

REPORT ON THE ECHINOIDEA. 97

and a large head, irregularly scattered among the others of the same kind as on the
abactinal side (PI. XVIII. * fig. 12). I have not found the peculiar tetradactyle pedicel-
larise (Echrnids of Porcupine, Trans. Eoy. Soc, 1874, pi. Ixvii. fig. 6) described by Thomson
as so characteristic of Phormosoma fenestratwn. In this species the ambulacral plates
perforated by the pores are larger than in Phormosoma placenta figured by Thomson.

Phormosoma tenue and Phormosoma uranus are at once readily distinguished from
Phormosoma ])lacenta on account of the greater similarity in the structure of the actinal
and abactinal surface of the test.

Station 274. Sept. 11, 1875. Lat. 7' 25' S., long. 152° 15' W.; 2750 fathoms;
bottom temperature, 0'9° C. ; radiolarian ooze.

Station 237. June 17, 1875. Lat. 34" 37' N., long. 140" 32' E.; 1875 fathoms;
bottom temperature, 1'7° C. ; mud.

Station 272. Sept. 8, 1875. Lat. 3° 48' S., long. 152° 56' W.; 2600 fathoms;
bottom temperature, 1'0° C. ; radiolarian ooze.

*Phormosoma luculentum (Pis. IX., X., X." figs. 3-7 ; PI. XXXIX. fig. 8 ; PI. XL.
figs. 31-36 ; PL XLIV. figs. 25-27.

Phormosoma luculcnta, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 201.

This is perhaps the most striking of the Echinothuridse collected by the Challenger.
The test is of a beautiful light violet colour, forming a brilliant contrast to the white
lines (Pis. IX., X., X." figs. 3, 4) indicating the sutures of the coronal plates, to the
jet black or deep violet, long smooth shiny primary spines, and to the silvery white
hoofs tipping the large primary spines of the ambulacral and interambulacral areas
scattered here and there along the edge of the test, when seen from the abactinal side,
and projecting over the lower surface of the test when seen from the actinal side. This
species is marked by the long narrow coronal plates of the abactinal surface (PL IX.
ficr. 1 ; PL X." fig. 3), the small size of the few primary tubercles irregularly placed on the
abactinal side of the test near the ambitus, the narrow ambulacral system, and the narrow
poriferous zone. The abactinal surface of the test is covered by short, sharp miliary and
secondary spines, few in number, and irregularly placed on the plates, leaving the test
nearly bare, although pitted with numerous miliaries carrying no spines (PI. X.^ fig. 3).
On the actinal side the primary tubercles are large, and are arranged in three more or
less regular horizontal rows near the ambitus (PL X.* fig. 4) ; these tubercles are sur-
mounted by large hollow cylindrical spines tipped with truncated conical hoofs (PL X.

fig. 1).

The small secondaries scattered over the actinal surface carry short club-shaped or
pointed spines (PL X. fig. 1). The flat intertubercular spaces are filled by short, sharp
miliary spines closely packed together between the larger primaries near the ambitus,

(ZOOL. CHALL. EXP.— PART IX.— 1881.) ^ 13

98 THE VOYAGE OF H.M.S. CHALLENGER.

but few in number between the secondary tubercles of the inner part of the test where
the white lines separating the coronal plates are again quite as prominent as on the
abactinal surface (PI. X. fig. 1), while on the outer third of the test towards the ambitus
the sutures of the plates are concealed by the thickened cuticle extending over the
scrobicular area of the large primary tubercles, and by the crowded miliaries and
secondaries. The miliaries, though more crowded, do not form (PI. X.'' fig. 4) as in
Phormosoma 2:>lacenta the very characteristic edge running along the - ambitus as
described by Thomson, which takes almost the prominence of a fasciole (see also
Phormosoma htrsarium for the description of a similar fasciole), and is interesting as
showing how such a structure may exist in a rudimentary form in the Desmosticha.

Both in this species and in Phormosoma bursarium (PI. X.*) the differences between
the primary spines of the actinal and abactinal surface is very striking. In the one
{Phormosoma luculenta) we have the actinal surface with its large hollow primary spines
tipped with the enormous white conical hoof (PI. X. fig. 1) and the small sharp or
club-shaped miliaries and secondaries, while the abactinal surface carries long slender
curved primary spines gradually tapering to a point with short, sharp secondary and
miliary spines (PI. IX. fig. 1). In the other {Phormosoma bursarium) the general
appearance of the abactinal spines (PI. X.*") is quite similar to that of Phormosoma
luculentum, while on the actinal side we find the remarkable primary spines with the bag-
like terminal appendage simulating the hoof of the other Echinothuridae. In Phormosoma
luculentum a few of the secondary ambulacral and interambulacral spines near the apical
system resemble the peculiar sheathed spines so characteristic of the whole of the
abactinal surface of Asthenosoma grubii (PI. X." figs. 5, 6).

The actinal membrane is covered by secondary tubercles arranged in irregular
concentric rings round the actinostome (PI. X. fig. 3 ; PI. X." fig. 4), carrying slender
spines slightly club-shaped at the end. The abactinal system is characterised by the
large size of the anal plates extending from near the central part of the anal system to
the edge of the abactinal system (PI. X. fig. 2 ; X.* fig. 3) ; each of these iiTegularly-
shaped plates carries from one to two slender secondary spines. The genital plates are
small and elUptieal, widely separated from the indistinct ocular plates by the plates of the
anal system encroaching upon the genital ring. The madreporic body is not prominent.

In this species, as in Phormosoma hoplacantha, the continuation of the poriferous
zone from the abactinal side to the actinostome is exceedingly irregular (PI. X. fio-. 1 ;
PL X.'' fig. 4), and although on the actinal side the sutures of the ambulacral and interam-
bulacral plates and of the poriferous zone are well defined, the poriferous zone never
becomes prominent and regular again as on the abactinal side.

Thomson has already noticed the very irregular course of the poriferous zone on the
actinal surface of Phormosoma (Porcupine Echinoidea, Trans. Roy. Soc, 1874).

The outline of this species seen in profile is probably more nearly correct than that

REPORT ON THE ECHINOIDEA. 99

of the others figured in the same attitude. The test of Pliormosoma luculentum is far
more rigid than that of many of the species of the family, so that with its stifi" flattened
actinal surface it clearly shows a rounded ambitus and a somewhat conical outline as in
Plate IX. fig. 2.

In a species of PJior-mosoma closely allied to Pliormosomxi placenta and Phormosoma
luculentum, which frequently came up in the dredgings of the "Blake" during the expedition
of 1878-79, the outline of the test when seen in profile was somewhat like the figure
of Plate IX. fig. 2, only the abactinal surface was more globular, and the flattened actinal
surface even sometimes bent upwards towards the edge near the ambitus. Still, in aU
these specimens of Phormosoma there was a very decided contrast between the flattened
actinal surface and the comparatively high globular abactinal surface.

In the species of Asthenosoma, on the contrary, there was no such contrast between
the actinal and abactinal surfaces, the outline being in living specimens when seen in profile
nearly globular, as if the test had been blown up like a football. This is seen in
specimens which came up from moderate depths near 100 fathoms, and in which no
difierence of pressure would account for such excessive expansion.

The very difierently shaped coronal plates composing the test of Phormosoma, near
the actinostome, in the outer half of the actinal surface, and on the abactinal surface of
the test (PI. X.* figs. 3, 4), as well as the striking difierence in the course and arrange-
ment of the poriferous zone on the two sides of the test, plainly show how hazardous it
is among the Palseechinidse to multiply the genera and species allied to Archceocidaris
and Pholidocidaris on structural features found combined in one and the same
species of the recent Echiuothuridse. In this species of Phormosoma {P. luculentum),
the fiat intertubercular space between the deeply sunken areolas of the primary spines
is broad, and does not form as in Phormosoma bursarium the weU-defined ridge so
characteristic of that species which recalls so strongly a similai- structural feature in
ArchcBOcidaris.

Station 200. October 23, 1874. Lat. 6° 48' N., long. 122° 25' E. ; 255 fathoms;
mud.

Station 205. November 13, 1874. Lat. 16° 42' K, long. 119° 22' E. ; 1050
fathoms; bottom temperature, 2-4° C. ; grey ooze.

Station 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' E. ; 800 fathoms;
bottom temperature, 3 '9° C. ; mud.

*Phormosoma bursarium, n. sp. (PI. X.'').

I was inclined at first to consider the specimens on which I have distinguished this
species as belonging to Phormosoma luculentum, and to regard them as younger specimens.
On a re-examination, and after a careful study of the younger stages of the difierent

100 THE VOYAGE OF H.M.S. CHALLENGER,

species of the group, I am compelled, for the present at least, to distinguish this species
from Phormosoina liiculentum, although it is found associated with it. It resembles
Phormosoma jdacenta in the closer tuberculation of the actinal surface (PI. X.'' figs. 3, 6),
and differs from both Phormosoma jplacenta and Phormosoma luculentum in the greater
height of its coronal plates, and the presence of large primary tubercles extending both
in the ambulacral and interambulacral areas far towards the abactinal system (PI. X.''
fig. 4). These primary tubercles carry long curved spines (PI. X."^ fig. 1), of a whitish-
yellow colour, and not filled with dark pigment as in Phormosoma luculentum. This,
however, I do not consider a character of importance, depending as it does entirely
upon the general colour of the test, which, in this sjjecies, is of a dirty orange-yellow,
with a slight violet tint. The primary spines are comparatively stouter than in
Phormosoma lucxdentum.

The most important feature which distinguishes this species at once from Phormosoma
luculentum is the comparatively large abactinal system (PL X.'' figs. 1, 4, 8), the genital
openings extending well into the median interambulacral space between the upper
coronal plates, and the larger number of the anal plates of the anal system than in
Phormosoma hiculentum. On the actinal surface (PI. X.^ fig. 2) the primary spines are
not tipped with a solid hoof, but all end in a fleshy bag (PL X.*" fig. 10), which gives
these spines much the appearance of those of the actinal surface of Microi^yga. There
are from two to three primary tubercles on each interambulacral plate near the ambitus,
and about half-way towards the abactinal system. In the ambulacra! area the large
primary tubercles extend nearly to the abactinal extremity of the ambulacrum. The
lines of miliaries, extending round the test immediately at the ambitus, are more
prominent than in Phormosoma luculentum (PL X.*" fig. 7) ; still they do not cor-
respond in the interior of the test to the remarkable band noticed by Thomson in that
species.

This species is also characterised by its extremely narrow poriferous zone which, even
on the abactinal surface, forms a more or less irregular vertical zone, composed of short
arcs of three pairs of pores, and placed in close proximity to the outer edge of the pori-
ferous zone (PL X.'' figs. 3, 4, 5, 7). The number of primary tubercles near the ambitus
is larger in Phormosoma bursarium than in Phormosoma luculentum. In a specimen
of the former measuring 28 mm., there are four primary interambulacral tubercles to each
plate, while in a large Phormosoma luculentum measuring 160 mm. there are only three
large primaries. The miliaries of the abactinal surface are somewhat larger also than in
Phormosoma luculentum, and less numerous ; the interambulacral coronal plates of the
latter species being pitted all over with miliary tubercles, sunk in the cutis of the test.
The ridges separating the deeply sunken areolas of the primary tubercles of the actinal
surface (PL X.'' fig. 6) are quite narrow in Phormosoma hursarium, while in Phormosoma
luculentum the primary tubercles near the ambitus are separated by flat spaces of the

REPORT ON THE ECHINOIDEA . 101

test, more or less wide according to the size of the tubercles. The structure of the
primary tubercles of the actinal surface, and their irregular arrangement in horizontal
and vertical rows is very characteristic of the genus Phormosoma, and resembles in
the most striking manner the arrangement and structure of the primary tubercles of
Archceocidaris among the Paleeechinidse, showing that Archceocidaris, and perhaps
Eocidaris and Pholidocidaris, are more closely related to the recent Echinothuridse
than the group of Pala3echinid8e, to which Melonites and the like belong, which, as
far as we can judge, from what we know of the structure of the apical system, and"
of the actinal membrane are more closely related to the Cidaridse.

The presence of sheathed spines in two species of Phormosoma shows that this
character, which at first sight seems to separate so strikingly from the rest of the
species of the group Asthenosoma gruhii, is evidently one of little value, and which
may be more or less developed in specimens of the same species in the same state
of growth.

In a specimen of Phormosomxi lucidentum, measuring nearly 160 mm. in diameter, the
abactinal system measured 22 mm., the actinal opening 42 mm.; while in a specimen of
Pliormosoma hursarium, measuring 100 mm. in diameter, the abactinal system measured
28 mm., the actinal opening 40 mm. The smaller specimens of these two species collected
from the same localities could readily be assigned to their respective species, yet more
abundant material may prove that the differences noticed, although important, are
simply individual characteristics partly due to age.

Station 200. October 23, 1874. Lat. 6° 48' N., long. 122° 25' E. ; 255 fathoms;
mud.

Station 205. November 13, 1874. Lat. 16° 42' N., long. 119° 22' E. ; 1050
fathoms; bottom temperature, 2 '4° C. ; grey ooze.

Station 232. May 12, 1875. Lat. 35° 11' N., long. 139° 28' E. ; 345 fathoms;
bottom temperature,- 5 "0° C, ; sandy mud.

'"^ Pliormosoma hoplacantlia (Pis. XL, XIL, XIL'' figs. 10-13; PL XXXIX. figs.
3-7 ; PI. XL. figs. 37, 38 ; PI. XLIII. fig. 1 ; PL XLIV. figs. 28-31).

Phormosoma hoplacantlia, Wy. Thomson, 1877, Voyage of Cball., Atlantic, vol. i. p. 148,
fig. 35.

This is the largest Sea-urchin with which I am acquainted, it measures no less than
312 mm. in diameter, and when fully expanded, must have been a striking object. This
species is remarkable for the large size of the primary tubercles, arranged both on the
actinal and abactinal surface of the interambulacral areas (PL XIL" figs. 11-13) in
horizontal rows ; on the abactinal surface they are distant, separated by large secondaries
and miliaries, irregularly arranged on the coronal plates (PL XIL'' fig. 13). Towards

102 THE VOYAGE OF H.M.S. CHALLEXGER.

the abactinal system the primaries decrease in size and number, leaving the abactinal
portion of the test covered by secondaries and miliaries for one-third the distance from
the abactinal system to the ambitus. The arrangement of the tubercles is similar in the
ambulacral system, the tubercles being, however, somewhat smaller. The primary spines
are cylindrical, hollow, of uniform length (PI. XL fig. 1) ; those of the actinal system are
capped with a gigantic, white, truncated conical hoof (PL XL fig. 2). The spines of
the secondary tubercles and of the miliaries are sharp, shorter, more slender, pointed,
and tapering. The actinal system (PI. XL fig. 2) is thickly covered with short
stouter spines, carried by the secondaries, and granules covering the plates of the
actinal membrane (PI. XIL fig. 4). The abactinal system is less well covered with
spines (PL XL fig. 3), the granulation of the anal system is quite uniform in size
(PI. XL fig. 4), and the anal system is towards its outer edge covered by large
irregularly-shaped plates, with slightly raised edges separating the plates of the genital
ring ; these plates carry no tubercles, only an indistinct granulation. The genital and
ocular plates are fringed by an irregular row of miliaries (PL XL fig. 4).

In Phormosoma, Yiewedi from the outside, and counting from the actinostome, the
whole up]Der edge of the plates of the ambulacra pass under the lower edge of the
succeeding plates, while in the interambulacral areas it is the lower edge which passes
under the upper edge of the preceding plate (PL XIL" figs. 11, 12).

Seen from the actinal side, the poriferous zone cannot well be traced through the
mass of spines, and when denuded, is seen to extend very irregularly towards the
actinostome (PL XIL fig. 4 ; PL XII.--" fig. 10).

As in PJiormosoina hursariwn, Phormosoma lolacenta, and other allied species, the
depressed areolas of the large primary tubercles of the actinal surface form distinct
projecting rings on the interior of the test (PL XIL* fig. 11).

In alcohol the colour of the specimens of this species is dark violet, almost black both
for the test and spines, and this formed a marked contrast to the white tips of the spines
on the actinal surface.

The existence of primary spines tipped with hoofs as in the Ai'baciadse is an
interesting structural feature connecting groups which thus far seemed somewhat isolated
in their relationship to other Echinids. Thomson in the Voyage of the Challenger (vol. i.)
figured these remarkable spines of the actinal surface of Phormosoma hoplacantha on
p. 148, fig. 35, where he speaks of the wear of the base of the cones as if they had been in
use for " vigorous locomotion " over the ground, as we know to be the case in one of
the species of Arbacia of the eastern North American coast. In the Echinothuridaa the
conical tip does not extend along the sides of the extremity of the spine, forming, as in
the Arbaciadse, a kind of cap ; it is merely attached by a nearly horizontal base to tlie
more flattened end of the spine. In consequence of this mode of attachment the tip is
frequently lost.

REPORT ON THE ECHINOIDEA. 103

Station 300. December 17, 1875. Lat. 33° 42' S., long. 78° 18' W. ; 1375 fathoms ;
bottom temperature, 1*5° C ; giobigerina ooze.

Station leia. June 13, 1874. Lat. 34° 13' S., long. 151° 38' E. ; 410 fathoms;
grey ooze.

Station 235. June 4, 1875. Lat. 34° 7' N., long. 138° O' E. ; 565 fathoms ; bottom
temperature, 3"3° C. ; mud.

*Pho7-mosoma uranus (PI. XVIIL" fig. 12).

Phm-mosoma uranus, Wy. Thomson, 1877, Voyage of the Challenger, Atlantic, vol. i. p. 146,
fig. 33, p. 147, fig. 34.

Thomson has figured in the Voyage of the Challenger (vol. i. p. 146, fig. 33, p. 147,
fig. 34), a species of Phormosoma difiering greatly from that collected by the Porcupine
and named by him Phormosoma placenta (Trans. Eoy. Soc, 1874, vol. cLxiv. part 2, p. 732,
Pis. Ixii. Ixiii.) ; the latter species was remarkable for the large tubercles of the
actinal surface occuppng with their areolas the greater part of the ambulacral and inter-
ambulacral plates. The present species is more closely related to Phormosoma tenue, in
-which the large tubercles are not closely packed but irregularly arranged and limited to
a comparatively narrow edge of the abactinal surface immediately adjoining the ambitus.
It differs also from specimens of Phormosoma tenue in the arrangement of the poriferous
zone, which is well shown by Thomson on fig. 34 ; the intercalated ambulacral plate
is proportionally large and still extends to the outer edge of the ambulacral area, the
poriferous zone thus forming a nearly vertical line (somewhat irregular) of pores
extending from the actinal opening to the abactinal area ; the species holds, as Thomson
has noticed, an intermediate place between Phormosoma and Asthenosorna.

The extreme tenuity of the test of this species is very remarkable, the coronal plates
of the abactinal area of the only specimen collected are so thin that the test can be rolled
up without injury to the specimen. The shape of the plates of the ambulacral zone on
the abactinal side at once distinguish this species from Phormosmna tenue, in which the
corresponding plates are comparatively narrower, while the primary ambulacral plates of
Phorraosoma uranus are fully as high as the corresponding interambulacral plates. This
is not the case in Phormosoma tenue (see PI. XIV. fig. 1).

Among the Echinoidea dredged by the last "Blake" expedition there are a number of
specimens of a species closely allied if not identical to Phormosoma uranus ; as these are
of all sizes I may be able to ascertain how far the characters which I have used to
distinguish Phormosoma uranus and its Pacific representative are constant.

Stttion 6. January 30, 1873. Lat. 36° 23' N., long. 11° 18' W. ; 1525 fathoms;
bottom temperature, 1 "6° C. ; giobigerina ooze.

Station 78. July 10, 1873. Lat. 37° 24' N., long. 25° 13' W. ; 1000 fathoms;
giobigerina ooze.

104 THE VOYAGE OF H.M.S. CHALLENGER.

Among tlie small specimens of Ecliinothuridse there are a few which I am unable to
refer satisfactorily to any one of the species here distinguished, and which are for the
present described under distinct names, the one as Phormosoma asterias and the other as
PTiormosoma rigidum, both these species differing from any of the species of Phormosoma
here described in having extremely narrow coronal plates more like the species of Asthen-
osoma allied to Asthenosoma grubii and Asthenosoma hystrix.

* Phormosoma asterias n. sp. (PI. XII. " figs. 7-9).

The only specimen collected measures 30 mm. in diameter, the whole abactiual
surface both in the ambulacra! and interambulacral areas is covered b}' primaries
arranged in somewhat irregular lines along the median lines of the plates (PL XII. " fig. 9)
with but few secondaries or miharies on the plates near the ambitus. On the actinal
surface, as in all young Phormosomas, there are from two to three primary tubercles
(PI. XII." fig. 8) with secondary tubercles and miliaries irregularly scattered over the
comparatively bare plates. The actinal membrane is as yet covered only hj the ten large
buccal plates with a couple of minute plates near the actinal edge of the test, the first
trace of the imbricating buccal j)lates of older stages. The course of the poriferous zone
is quite sporadic, and the Limitation of the ambulacra! and interambulacral areas ill-
defined near the actinostome. In addition to these features the abactinal system is
remarkable for the large size of the anal plates in so young a specimen, for the elongated
pear-shaped ocular plates and the large triangular genital plates, some of which show
traces of subdivision, as if the proximal extremities of the genital plates eventually
became cut off to form a part of the anal system.

Colour of test light yeUo wish-red.

Station 299. December 14, 1875. Lat. 33° 31' S., long. 74° 43' W. ; 2160
fathoms ; bottom temperature, 1'1° C. ; grey mud.

*Phormosoma rigidum n. sp. (PI. XII.* figs. 1-4).

The largest specimen collected measured only 40 mm. in diameter, and might readily pass
as the young of some species of Astropyga Avere it not for the characteristic Phormosoma
structure of the actinal surface (PI. XII. " fig. 3) and of the abactinal system. The
poriferous zone of this species is extremely narrow, more so than in corresponding stages
of other species of Phormoso7na (PL XII. ^ fig. 4), and it is still confined to the very outer
edge of the ambulacral zone. The coronal plates of the actinal surface in both areas
carry already two large primary tubercles (PI. XII." fig. 3), and the areolas show a slight
trace of difference of level with the surrounding test, so that the whole of the actinal
surface of the test appears thickly covered with large primary tubercles much as in Phor-
mosoma placenta. The coronal jjlates of the abactinal surface are narrow and elongated,
carrying, according to their size and position, from two to three primaries (PI. XII. " figs.

REPORT ON THE ECHINOIDEA. 105

1, 4), arranged iu horizontal rows on the central part of the plate and forming indistinct
vertical rows. There are but few small secondaries and mUiaries. The abactinal system
is large (PI. XII.* fig. 2) ; the ocular plates are small, somewhat pear-shaped, scarcely-
exceeding in size some of the larger of the many plates covering the anal system ; the
genital plates are short, triangular. The colour of this species in alcohol is light violet-
brown, the primary spines are slender pointed and comparatively short on the abactinal
surface, stouter and somewhat larger on the actinal side.

Station 169. July 10, 1874. Lat. 37° 34' S., long. 179° 22' E. ; 700 fathoms;
bottom temperature, 4*2° C. ; grey ooze.

ECHINOMETRAD^.
Family Echinometbad^, Gray, 1855, Proc. Zool. Soc. Lond.

Heterocentrotus.
Heteroccntrotus, Brandt., 1835, Prod. Des. An.

Heterocentrotus mammillatus.

Gidaris mammiUafa, Klein, 1734, Nat. Disp. EcL
Heterocentrotus mammillatus, Brandt, 1835, Prod.

Kandavu Eeef.
Heterocentrotus trigonarius.

Echinus trigonarius, Lamk., 1816, Anim. sans Vert.
Heterocentrotus trigonarius, Br., 1835, Proc. Desc.

New Caledonia.

Echinometra.

Echinometra, Rondel, 1554, De Piscib. Mar. (Breyn.).

Echinometra lucunter.

Cidaris lucunter, Leske, 1778, Kl Add.
Echinometra lucunter, Blainv., 1834, Actin.

Samboangan, 10 fathoms.

Kandavu Reef.

Tongatabu Eeef. 18 fathoms. July 24, 1874.

Papeete Reef. September, 1875.

Honolulu. August, 1875.

Cebu, Philippine Islands.

(zool. CHALL. EXP. — PART IX. — 1881.) 1 14

106 THE VOYAGE OF H.M.S. CHALLENGEE.

Echinometra siihangularis.

Cidaris subaiigiilaris, Leske, 1778, Kl. Add.
Echinometra subangularis, Desml., 1837, Syn.

St Vincent, Cape Verde Islands.
Ascension Island, sliore.

StrongylocentrohLS.
Strongylocentrotus, Brandt., 1835, Prod. Des. An.

Strongylocentrotus drohachiensis.

Echinus Drobachiensis, Mull., 1776, Zool. Dan. Prod.

Strongylocentrotus Drobachiensis, A. Agassiz, 1872, Eevis. Echini, part 1, p. 162.

Station 48. May 8, 1873. Lat. 43° 2' N; long. 64° 2' W., 51 fathoms; rocks.
Le Have Bank.

Station 49. May 20, 1873. Lat. 43° 3' N; long. 63° 39' W., 83 fathoms; bottom
temperature, 1"8° C. ; gravel, stones.

Strongylocenti 'Otus e urythrogrammus.

Echinus eurythrogrammus, Val., 1846, Voyage V^nus.

Strorigylocentrotits eurythrogrammus, A. Agassiz, 1872, Eevis. Echini, pai-t 1, p. 163.

Port Jackson, 6 to 15 fathoms and 30 to 35 fathoms.
New Caledonia.

Strongylocentrotus gibhosus.

Echinus gibbosns, Val., 1847, in Ag. Des., C. E. Ann. Sc. JSTat., vol. vii.
Strongylocentrotus gibbosm, A. Agassiz, 1872, Eevis. Eoliini, part 1, p. 164.

Station 304. December 31, 1875. Lat. 46° 53' S., long. 75° 11' W. ; 45 fathoms ;
sand.

Sphcerechinus {Strongylocentrotus).

Sphmrechinus, Desor, 18.57, Syn. £ch. foss.

SphcBrechinus australice.

Sphcerechinus Aiistralice, A. Agassiz, 1872, Bull. Mus. Comp. Zoo!., vol. iii.
Station 162. April 2, 1874. Bass Strait; 38 to 40 fathoms; sand.

Sphcerechimts granularis.

Echinus granularis, Lamk., 1816, Auim. sans Vert.

SphcBrechinus granularis, A. Agassiz, 1863, Bull. Mus. Comp. Zool., voL i.

St Vincent, Cape Verde Islands.

REPOET ON THE ECHINOIDEA. 107

Station 75. July 2, 1873. Lat. 38° 37' N., long. 28° 30' W. ; 50 to 90 fathoms;
sand.

Pseudoholetia {Strongylocentrotus).
Pseudoboletia, Trosch., 1869, Verhdl. d. Nat. Ver. f. EheinL u. "West.

Pseudoholetia indiana (PI. XXXVIII. fig. 3, PI. XXXIX. fig. 11, PI. XLIV. figs.
38-40).

Toxopneiides indicmus, Mich., 1862, Maill. Boiubon, Ann. A.
Pseudoboletia indiana, A. Agassiz, 1872, Eevis. Echini, part 1, p. 153.

Samboangan ; 10 fathoms.

ECHINID.E.

Family Echinid^, Agassiz, 1846, C. E. Ann. Sc. Nat., vol. vi. (emend.).

Temnopleuridj;.
Sub-family TEMNOPLEURiD^a), Des., 1855, Syn. fich. foss.

Temnopleurus.
Temnopleurus, Agassiz, 1841, Int. Mon. Scut.

Temnopleurus Tiardioicki.

Toreumatica Hardioickii, Gray, 1855, Proc. ZooL Soc. Lond.
Temnopleurus Hardmckii, A. Agassiz, 1872, Eevis. Ech., part 1, p. 166.

Kobi, Japan. 8 to 52 fathoms. May 17, 1875.
Arafura Sea.

02" Yokohama. 8 to 14 fathoms and 5 to 25 fathoms.

Station 192. September, 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129
fathoms ; mv;d.

Temnopleurus reynaudi.

Temnopleurus Reynaudi, Agassiz, 1846, C. E. Ann. Sc. Nat., voL vi. "

Station 192. September 26, 1874. Lat. 5° 42' S., long. 132° 25' E. 129 fathoms;

mud.

Station 219. March 10, 1875.. Lat. 1° 50' S., long. 146° 42' E. 150 fathoms;

mud.
■ Station 166. June 23, 1874. Lat. 38° 50' S., long. 169° 20' E. 275 fathoms ;

bottom temperature, 10-0° C. ; globigerina ooze.

108 THE VOYAGE OF H.M.S. CHALLENGER.

Temnopleurus toreumaticus.

Cidaris toreumaticu, Klein., 1734, Nat. Disp. Ech.
Temnopleurus toreumatieus, Agassiz, 1841, Int. Mon. Scut.

Station 203. October 31, 1874. Lat. 11° 7' N., long. 123° 7' E.; 12 to 20 fathoms;
mud.

Pleurechinus (Temnopleurus).

Pleurechinus, A. Agassiz, 1841, Int. Mon. Scut,

Pleurechinus hothyroides (PI. X." figs. 1,2). '

Pleurechinus hothryoides, Agassiz, 1841, Int. Mon. Scut.

The Challenger collected three small specimens of a Temnopleurid, which I am
inclined to refer to the sub-genus Pleurechinus, Agassiz (see Revis. Echini, p. 465);
they are unfortunately not large enough to compare .directly with the typical Pleurechinus
hothryoides. They show clearly, however, that we may expect to find in the China Seas a
species of Temnopleurus still retaining the principal features so characteristic of some of
the nummulitic species of India, figured by D'Archiac and Haime (Animaux fossiles de
rinde, see Plate XIII. fig. 7, of Temnopleurus valenciennesi) , to which the specimens of
the Challenger are most closely allied. The outline of the test, even in these young sjDeci-
mens, measuring (the largest) not more than 18 mm. in diameter, is high, resembling
already -somewhat the globular shape of such species of Amhhjpncustes as Amhlypneustes
griseus, and difiering from the other species of Temnopleurid^ in which the outline of
the test is quite conical at a corresponding stage. The genital ring (PL X.'' fig. 1) is
narrow, compact, slightly pentagonal; the genital plates are of uniform size, with the ex-
ception of the madreporic genital which is somewhat larger and rectangular in outline,
the pores covering its entire surface with the exception of the space occupied by the ring
of secondary tubercles, which runs along the inner edge of the genital plates, separating
them from the anal system (PL X." fig. 1). In addition to this edging of secondar}'
tubercles, the genital plates' carry from two to three similar tubercles irregularly placed
on the plates and a few miliaries. The genital openings are deep crescent-shaped notches,
cut out of the outer edge of the plates; the genital plates are united along the anal edge,
and a distinct pit in the angle of the sutures between the genital and ocular plates
separates the latter from the edge of the anal system. The anal system is covered by
an outer row of large triangular plates with smaller slender elongate plates arranged
round the anal openings. In the interambulacral area there are two disconnected
elliptical pits at the two extremities of the horizontal sutures, separating the coronal
plates (PL X.* fig. 2). The coronal plates carry from one to three large primary
tubercles arranged in a horizontal row near the lower edge of the plate, with a
somewhat undulating horizontal line of smaller secondary tubercles above that, the

REPORT ON THE ECHINOIDEA. 109

rest of the plate being filled with granules, miliaries, and secondaries, u-regularly
arranged. In the amhulacral area the pits are only slightly smaller, but there is
only a single large pit at the median end of the suture, the pit at the other extremity
of the suture is reduced to a minute impression at the angle of the coronal plate
adjoining the poriferous zone. There is a distinct vertical row of primaiy tubercles
on the outer edge of the coronal plates, extending along the whole length of the
poriferous zone, the rest of the ambulacral plate is occupied by an inner somewhat
smaller tubercle, and an irregular horizontal line of secondaries with miliaries extending
above the larger tubercle. The pores form very indistinct irregular vertical arcs of three
pairs ; the pores are separated by slight ridges, and the miliaries of the coronal plates
sometimes encroach on the outer edge of the poriferous zone.

In alcohol the test is greenish, the tubercles standing out in greyish-white ; the spines
are short, slender, resembling those of Salmacis ; they are yellowish, with three to four
reddish-orange transverse bands more or less distinct.

Galapagos is mentioned as the habitat of this species in the Eevision of the Echini;
this is evidently a mistake, as thus far no species of Temnopleuridaj have been recorded
from that locality. The specimens collected by the Challenger show conclusively that
this genus has the same geographical range as the other members of the family.

'station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' K; 8 fathoms;
coral sand.

Kobi, Japan; 8 to 50 fathoms. May 17, 1875.

"' Prionechinus.

Pi-kmecMniis, A. Agassiz, 1879, Proc. Am. Acad., vol xiv. p. 202.

The structure of the apical system of this genus is closely allied to that of the
Salmacidse. It resembles more, perhaps, that of the genus Coi:>t02ihyma of Peron and
Gauthier, figured on plate xv. fig. 1 1, ]6chin. foss. d'Algerie, Cotteau, Peron et Gauthicr ; but
as in Cottaldia, there is Isut a single row of plates of pores of equal size in the ambulacral
zone. The actinostome is somewhat indented, and the actinal membrane is covered by
pktes. The spines are seiTated, somewhat flattened, differing radically in external
appearance from the spines of the Triplechinidae thus far known.

'•"Prionechinus sagittiger (PI. VI." figs. 11-14; PL XL. figs. 43, 44).

PrionecMnim sagittiger,- A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 202.

Unfortunately only poorly-preserved specimens of this interesting genus were

collected; the largest, measuring 7-5 mm. in diameter, is evidently immature, though

the genital openings are well developed. The actinal system of this species has ten large

' buccal plates (PI. VI.-'' fig. 12), with others irregularly arranged; it resembles that of the

110 THE VOYAGE OF H.M.S. CHALLENGER.

Echinidse, of such forms as Echinus miliaris, but the opening of the actinostome is
comparatively larger. In all the buccal plates the tentacle of one of the pairs is rudi-
mentary or even wanting (PI. VI.^ fig 12). The test is thin, much as in the Salmacidae,
and it has as well as the spines a silvery lustre as in Trigonocidaris. The coronal plates
are high ; the pairs of large pores are arranged in a single vertical row.

The anal system is large, but still covered with a few large plates as in all young
Echinidse (PL VI.'* fig. 13). The genital plates are of uniform size ; the ocular plates are
notched in the apex of the ambulacral row, they are excluded from the anal system. The
primary tuberculation of the upper part of the test extends over the genital ring. The
pedicellariaj are numerous, especially above the ambitus ; they are all of tbe large-headed
slender-stemmed form. The most striking feature of this genus, however, is the structure
of the spines; thus far it was mainly among Cidaridse, Salenidee, Diadematid^, and
Arbacidae, that the spines differed greatly in shape, in closely allied genera, or even in the
species of the same genus. Among the Echinidse, though we find in very young specimens
marked serrations along the fluting of the spines, yet these disappear with age, forming a
more or less uniform fluting in all the Echinidee proper. In this genus, however, the spines
of the test are still prominently serrated in comparatively large specimens (PI. VI."
figs. 11, 11a), at least in specimens of a size which, in the young Echinid^ which have
been examined, have all the features of the adult. In addition to the serrations they are
also flattened (PI. VI.* fig. 11a), resembling to a considerable extent some of the spines
of Salenia varispina. What shape they assume in the adult will be interesting to dis-
cover. This genus is most interesting, as it is the first instance showing any relation-
ship in the shape of the spines, between the genera of the Echinidge proper, and the
Cidaridse and Salenidse, in addition to the common structural features of the actinostome.
This genus has also affinities to Trigonocidaris and others of the Salmacidse as stated
above.

The test is flattened, the actinal cuts are slight; there is one large primary tubercle
on each coronal plate both of the ambulacral and interambulacral areas, forming in both
areas very distinct vertical rows ; the rest of the interambulacral plates carry small second-
aries irregulary arranged round the centrally placed primary (PI. VI."* fig. 14); in the
ambulacral area the primaries are near the median line, separated from the poriferous
zone by irregular arcs of secondaries. The poriferous zone is comparatively broad, the
pairs of pores well separated vertically.

Station 164. June 12, 1874. Lat. 34° 8' S., long. 152° 0' E.; 950 fathoms; bottom
temperature, 2"2° C. ; grey ooze.

Station 218. March 1, 1875. Lat. 2° 33' S., long. 144° 4' E.; 1070 fathoms;
bottom temperature, 2'1° C. ; globigerina ooze.

Station 207. January 16, 1875. Lat. 12° 21' N., long. 122° 15' E; 700 fathoms;
bottom temperature, 10 '8° C. ; mud.

REPORT ON THE ECHINOIDEA. Ill

Microcyiihus.

Mierocyplms, Agassiz, 1841, Val., Anat. Genre. Ech. {iwn Mon. Scut.).

Microcyphus zigzag.

Microeyphtis zigzag, Agassiz, 1846, C. E. Ann. Sc. Nat., vol. vi.
Station 161. April 1, 1874. Off entrance to Port Philip; 38 fathoms; sand.
Station 162. April 2, 1874. Off Ea.st Moncceur Island, Bass Strait; 38 to 40
fathoms ; sand.

Trigonocidaris.
Trigonoeidaris, A. Agassiz, 1869, Bull. Mus. Comp. Zool., vol. i.

Laube has figured among the fossil Echinoidea of Murray Cliffs in Southern Australia a
small Sea-urchin (Paradoxechinus novus), of which he gives an enlarged view of a part of
the ambulacral and interambulacral areas. I am inclined to consider this interesting fossil
as the Tertiary representative of Trigonocidaris. Laube's genus is probably identical
with Trigonocidaris, but not having an authentic specimen I am unable to settle this
point, and here merely call attention to their probable identity. The difference in the
structure of the connecting ridges between the primary tubercles may be due to the state
of preservation of the fossil. Laube's genus was described in the Sitzungsb. Akad. Wien.,
February 1869, while my preliminary description of Trigonocidaris did not appear till
October of the same year.

According to the description of the ornamentation and the detail figures the ridges of
Paradoxechinus are double zigzag lines of small tubercles, whQe in Trigonocidaris the
zigzag lines uniting the tubercles are smooth ridges forming an irregular network of pits
very unlike the regular triangles formed by the ridges connecting the primary tubercles.
The only other genus of Echinids presenting such a structural feature is Pleurodiadema of
Loriol (an oolitic form), in which, however, this arrangement of the granules or miliaries
is in distinct ridges, but in this genus always running horizontally.'

* Trigonocidaris monolini (PI. VI." figs. 8-10).

Trigonocidaris monolini, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 203.

A single specimen from Station 170, measuring 8 mm. in diameter. This species is
readily distinguished from Trigonocidaris alhida by the structure of its actinal membrane
(PL VI.''' fig. 8); and also by the striking ornamentation of the genital ring (PI. VI. " fig. 9) and
by the relatively smaller number of primary coronal plates and their coarser pitted reticula*
tion (PI. VI." fig. 10). The ten ambulacral buccal plates of the actinal membrane occupy
nearly the whole of the distal edge of the actinal ring, while in specimens of the same
size of Trigonocidaris alhida the pairs of plates are separated not only from each other

I See Cotteau, 'fichinides Nouveaux, Eev. Mag. Zool., No. 97, pi. xxvi.

112 THE VOYAGE OF H.M.S. CHALLENGER.

but from the edge of the test by the imbricating plates wHich cover the whole of its
actinal membrane. In this species the imbricating plates are more prominent in the
space between the teeth and the ambulacral plates (PL VI.* fig. 8). The characteristic
reticulation and pits of this genus are coarser both in the ambulacral and interambulacral
spaces ; the spines were mostly broken, but to judge from the secondary ones they must
have been proportionally longer and stouter than in the Florida species. The shape of
the anal system is not elongate in tlie direction of the axis of the large anal plate but at
right angles to it, and the second and third anal plates are comparatively larger than in
Trigonocidaris alhida with two vevj minute plates intercalated over the anal opening
between them and the small fourth anal plate (PL VL" fig. 9). The abactinal system is
ornamented by a prominent ridge, extending round the edge of the ocular plates and
across the adjoining genital plates, forming a pentagon with rounded angles round the
anal system (PL VI." fig. 9).

Adjoining the anal system in the middle of the genital plates are placed two or three
jDrominent secondary tubercles. This highly-ornamented apical system is in striking
contrast to the smooth liare abactinal system of Trigonocidaris albida. The pedicel-
lariee resemble those of Trigonocidaris cdbida, but the head is somewhat blunter ; in the
single specimen collected they were most numerous close to the ambitus on the abactinal
surface. In alcohol the colour of the test and spines of this specimen was silvery white
with yellowish suckers on the abactinal side. The actinal side of the test was of a light
dirty yellow.

Station 170. July 14, 1874. Lat. 29° 55' S., long. 178° 14' W. ; 520 fathoms;
bottom temperature, 6"0° C. ; rocks.

Cottaldia, Des.
Cottaldia, Des., 1855, Syii. Ech. Foss.

* Cottaldia forhesiana (PL VI." figs. 15-17).

Cottaldia forhesiana, Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 203.

Only a single specimen of this interesting species was obtained from Station 1 73. It is
allied to the Tertiary Psammechinus monilis. The pores are, however, arranged in simple
vertical rows much as in Temnechinus (PL VI.* fig. 15); the spines of this species (PL
VI.* fig. 17) closely resemble those of some species of Salmacis and of Temnechinus. It
has, like Temnoj^Ieurus and the allied genera, a large abactinal system, but we find no
trace of the indentations, grooves or pits of the above-mentioned genera. The general
facies of the test when denuded resembles that of the species often united by Echinologists
as Psammechinus \_Echinus, pars] The actinostome is sunken as in Temnopleurus
and Salmacis, a character in which it difi'ers from Cottaldia ; it may be best, however,
to place it in that genus for the present until we have more material to ascertain its

REPORT ON THE ECHINOIDEA. 113

true position. It has not, like the recent species of the old genus Psaimnechinus, the
actinostome covered with plates ; there are but ten large plates round the actinal opening ;
the madreporic body is slightly developed.

The spines are white and of a yellowish-orange at the base, short, slightly flattened,
and deeply grooved (PL VI. " fig. 17). The primary tubercles are of the same size in both
areas, forming a very marked vertical row in the ambulacral area ; the secondaries are
larger in the interamlsulacral spaces, they form indistinct horizontal rows near the
ambitus (PI. VI.* fig. 15). The genital plates are thickly covered by secondaries ; the
anal system is covered by comparatively few plates (PI. VI.* fig. 16). The genital open-
ings are small and sharply cut. This is evidently a young specimen. The colour in
alcohol is yellowish-orange with whitish primary spines.

Station 173. July 24, 1874. Lat. 19° 10' S.,long. 179° 40' E.; 315 to 310 fathoms ;
coral.

Salmacis.

Salmacis, Agassiz, 1841, Val., Anat. Genre Echiaus.

Salmacis hicolor.

Salmacis hicolor, Agassiz, 1841, VaL, Anat. Gen. Ecli.
Samboangan; 10 fathoms.

Salmacis dussumieri.

Salmacis Ditssumieri, Agassiz, 1846, C. R. Ann. Sc. Xat., vol. vi.
Station 212. January 30, 1875. Lat. 6° 55' N., long. 122° 15' E. ; 10, 14, and
20 fathoms ; sand.

Amboyna; 100 fathoms.

Salmacis glohator.

Salmacis glohator, Agassiz, 1846, C. R. Ann. Sc. Nat., vol. vi.
Station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' E. ; 8 fathoms;
coral sand.

Salmacis rarispina.

Salmacis rarispinus, Agassiz, 1846, C. R. Ann. Sc. Nat., vol. vi.
Station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' E. ; 8 fathoms;
coral sand.

Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E. ; 28 fathoms;

mud.

Station 203. October 31, 1874. Lat. 11° 7' N., long. 123° 7' E. ; 12 to 20 fathoms ;

mud.

(ZOOL. CHALL. EXP. — PART IX. — 1881.) I 15

114 VOYAGE OF H.M.S. CHALLENGER.

Salmacis sulcata.

Salmads sulcatus, Agassiz, 1846, C. E. Ann. Sc. Nat., vol. vi.
Cebu, Philippine Islands. May 23, 1875.

Mesiyilia.
Mespilia, Des., 1846, in Agassiz, Des. C. E, Ann. Sc. Nat., vol. vL

Mespilia glohuhis.

Cidaris gramdcda, Leske, 1778, Kl. Add.

Mespilia glohulus, Agassiz, 1846, C. R. Ann. So. Nat., vol. vi.

Samboangan ; 10 fathoms. February 1, 1875.

Amblypnevstes.

Amhlypneustes, Agassiz, 1841, Int. Mon. Scut.

Ainhlypneustes formosus.

Amhlypneustes formosiw, Val., 1846, Voyage V6nus.
Station 162. April 2, 1874. Bass Strait ; 38 to 40 fathoms ; sand.

Holopneustes {Ainhlypneustes).

Holopneiistes, Agassiz, 1841, Anat. Genre Echinus.^

Holopneustes p>urpuvescens.

AmUypnemtes imrpiirescens, Liitk., 1872, in A. Agassiz, Bull. Miis. Comp. Zool., vol. iiL
Holopneustes purpurescens, A. Agassiz, 1872, Bull. Mus. Comp. Zool., vol. iii.

Port Jackson ; 6 to 1 5 fathoms.

Triplechinid^.
Sub-family Thiplechinid.e, A. Agassiz, 1872, Revis. Ech., part 2.

£Jchinus.

Echinus, Eondel., 1554, De Piscib. (Linn.) {emend.).
Echinus acutus.

Echinus aeutus, Lamk., 1816, Anim. sans Vert.

Station 343. March 27, 1876. Lat. 8° 3' S., long. 14° 27' W. ; 425 fathoms;
bottom temperature, 4*5° C. ; coral.

Station 170. July 14, 1874. Lat. 29° 45' S., long. 178° 11' W. ; 630 fathoms;
bottom temperature, 4'0° C. ; rock.

'■ Not Mon, Scut, as in Revis. Ech., p. 483.

REPOET ON THE ECHINOIDEA. 115

Station 46. May 6, 1873. Lat. 40° 17' N., long. 66° 48' W. ; 1350 fathoms;
bottom temperatui'e, 2*3° C. ; mud.

Echinus angulosus.

Cidaris angulosa, Leske, 1778, Kl. Add.

Ecldims angulosiis, A. Agassiz, 1872, Eevis. EcL, part 1, p 122.

Simon's Bay; 10 to 20 fathoms.

Echinus elegans.

Echinus elegans (Dub. o. Kor.), 1844, Skand. Ech.

Station 46. May 6, 1873. Lat. 40° 17' N., long. 66° 48' W., 1350 fathoms;
bottom temperature, 2'3° C. ; mud.

Tristan da Cunha; 1100 fathoms.

Station 219. March 10, 1875. Lat. 1° 50' S., long. 146° 42' E. ; 150 fathoms
mud.

* Echinus horridus (PI. VL" figs. 1-5).

Echimis horridus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 203.

Fragments of a large conical Echinus were collected in the Straits of Magellan,
which I am unable to refer to any of the species already known from that locality. It
is readily characterised by its narrow poriferous zone, with its three pairs of pores, distant
and placed in nearly vertical arcs on the abactinal surface (PI. VL" figs. 3-5), but so
spaced that the two outer pairs form one vertical line, and the inner a second one ; on
the actinal side the poriferous zone is wider, the arcs are more horizontal, and placed
nearer together (PI. VL" fig. 4). Both in the ambulacral and interambulacral areas, the
single primary tubercle placed on each coronal plate (PL VL" figs. 3, 4, 5) forms a most
distinct vertical row. On the actinal side the primaries of both areas are nearly of a size
(PI. VL" fig. 4), but on the sides of the test, above the ambitus, the ambulacral primaries
decrease in size more rapidly than the corresponding interambulacral ones, as they
approach the abactinal system (PI. VL" figs. 3, 5). On the actinal side the secondaries
are irregularly arranged, and the intertubercular space of the plates is closely packed
with miliaries and small secondaries, showing no definite arrangement (PI. VL" fig. 4).

On the sides of the test, however, some of the larger miliaries and secondaries form
diverging lines more or less parallel to the horizontal sutures of the plates (PI. VL" figs.
3-5). This linear arrangement of the secondaries and miliaries is most prominent near
the ambitus (PI. VL" fig. 3). The primary spines (PI. VL" fig. 2) are remarkable for
their length, being even comparatively longer than in some specimens of Echinus acutus.
The actinostome is comparatively smaller than in any other species of this genus, not as
large as the abactinal system, with but slight buccal indentations. The actinal system was

116 THE VOYAGE OF H.M.S. CHALLENGER.

entire only in a medium-sized specimen, but the fragments of the actinostome of a large
specimen show that it does not increase greatly with age. The colour of the test (when
dry) is light reddish-brown, the miliary and secondary spines of a darker colour, the
shaft of the primary spines of the same colour as the test, somewhat darker at the base.

The aliactiual system is remarkal)ly compact and solid, with five large heptagonal
plates covered by a close granulation of small secondaries (PI. VI." fig. 1), with large
genital openings placed close to the outer edge of four of the plates. The madreporic
plate is somewhat larger than the others, the madreporic body covering nearly the whole
plate with the exception of the anal edge of the plate, which is covered by small
secondaries like the other plates. The ocular plates are of uniform size, irregularly
pentagonal, extending but little beyond the edge of the genital plates ; they are covered
with smaller secondaries than the genitals ; the ocular pore is large. The anal system is
covered by an outer row of large plates, one of which from its size is probably the
original anal plate of the young, the rest of the anal system is covered by small
irregularly-arranged plates (PI. VI." fig. 1).

There are two kinds of pedicellariee, one small-headed, long-stemmed; the other short-
stemmed with a conical head ; the latter are the more numerous on the test.

This species is closely allied to Echinus norvegicus, judging at least from the medium-
sized specimen, measuring 47 mm. in diameter (actinostome 8 mm.). This species,
however, from the size of the fragments of the sides of the test, must attain a height of
nearly 100 mm.

It has, like Echinus microstoma of Thomson (Porcupine Echinoidea, Trans. Eoy. Soc,
vol. clxiv. part 2, pi. Ixviii. fig. 1), a small, somewhat sunken actinostome, but difiers from
it in the arrangement of the secondaries and miliaries.

Station 308. January 5, 1876. Lat. 50° 10' S., long. 74° 42' W. ; 175 fathoms; mud.

Echinus magellanicus.

Echinus magellanicus, Phil., 1857, Wieg. Arch., vol. i.

Station 315. January 26, 1876. Lat. 51° 40' S., long. 57° 50' W.; 5 to 12 fathoms ;
sand and gravel.

Station 304. December 31, 1875. Lat. 46° 53' S., long. 75° 11' W. ; 45 fathoms ; sand.

Station 308. January 5, 1876. Lat. 50° 10' S., long. 74° 42' W. ; 175 fathoms ; mud.

Marion Islands ; 50 fathoms.

Station 145. December 27, 1873. Lat. 46° 40' S., long. 37° 50' E.; 310 to 315
fathoms. Prince Edward Island.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. ; 1600 fathoms;
bottom temperature, 0'8° C. ; globigerina ooze.

Station 312. January 13, 1876. Lat. 53° 38' S., long. 70° 56' W. ; 10 to 15 fathoms;
mud.

REPORT ON THE ECHINOIDEA. 117

Echinus margaritaceus.

Echinus margaritaceits, Lamk., 1816, Anim. sans Vert.

Studer (Monatsb. Berlin Akad, 1876, p. 456) has distinguished as distinct from
Echinus margaritaceus a species which he has named Echinus diadema, this he
separates on account of the absence of rows of secondary tubercles.

The Challenger has also collected from Kerguelen Island, 120 fathoms, specimens
answering well to Studer's description, but I am not inclined to consider these specimens
as a species distinct from Echinus 'margaritaceus after comparing them with specimens of
this species collected by the " Hassler " in the Straits of Magellan, and on the east coast
of Patagonia, as in some of these specimens there is a well marked tendency in the second-
ary tubercles to be arranged in horizontal and sometimes also in indistinct vertical rows.

Station 150. February 2, 1874. Lat. 52° 4' S., long. 71° 22' E. ; 150 fathoms;
bottom temperature, 1"8° C. ; rocks.

Station 151. Februar}^ 7, 1874. Off Heard Island ; 75 fathoms ; mud.

Station 308. January 5, 1876. Lat. 50° 10' S.,long. 74° 42' W. ; 175 fathoms ; mud.

Off Christmas Harbour, Kerguelen ; 50 fathoms and 120 fathoms. January 29, 1874.

Kerguelen Island ; 120 fathoms.

Station 311. January 11, 1876. Lat. 52° 50' S., long. 73° 53' W. ; 245 fathoms;
bottom temperature, 7 '7° C. ; mud.

Echimis norvegicus.

Echinus norvegicus, Diib. o. Kor., 1844, Skand. Ech.

Station 308. January 5, 1876. Lat. 50° 10' S., long. 74° 42' W. ; 175 fathoms ; mud.

Station 232. May 12, 1875. Lat. 35° 11' N., long. 139° 28' E. ; 345 fathoms;
bottom temperature, 5'0° C. ; sandy mud.

Station 235. June 4, 1875. Lat. 34° 7' N., long. 138° O' E. ; 565 fathoms;
bottom temperature, 3'3° C. ; mud.

Station 46. May 6, 1873. Lat. 40° 17' N., long. 66° 48' W. ; 1350 fathoms;
bottom temperature, 2'3°C. ; mud.

Station 47. May 7, 1873. Lat. 41° 15' N., long. 65° 45' W. ; 1340 fathoms;
mud.

Toxopneustes.
Toxopneustes, Agassiz, 1841, Int. Monog. Scut.

Toxopneustes pileolus.

Echinus pileolus, Lamk., 1816, Anim. sans Vert.
Toxopneustes pileolus, Agassiz, 1841, Int. Monog. Scut.

Samboangau ; 10 fathoms.
Honolulu. '

118 THE VOYAGE OF H.M.S. CHALLENGEK.

Toxopneustes variegatus.

Echinus variegatus, Lamk,, 1816, Anim. sans Vert.
Toxopneustes vanegatus, A. Agassiz, 1872, Eevis. Ech., part 1, p. 168.
Bermudas,

Hipponoe.
Hipponoe, Gray, 1840, Sjnops. Cont. Brit. Mus.
Hipponoe variegata.

Gidaris variegata, Leske, 1778, KL Add.

Hipponoe variegata, A. Agassiz, 1872, Eevis. Ech., part 1, p. 135,

Samboangan; 10 fathoms. October 25, 1874,

KandavTi Reef.

Port Jackson ; 6 to 1 5 fathoms.

Evechinus {Hipponoe).
Evediimts, VerrOl, 1871, Notes on Kadiata.
Evechinus chloroticus.

Echinus chloroticus, Val., 1846, Voyage V^nus.
Evechinus chloroticus, VerriU, 1871, Notes on adiata.

Kandavu Reef, Fiji Islands.

CLYPEASTEIDA.

Sub-order Clypeastrid^, Agass, 1836, Prod. Mon, Ead.

EUCL YPEASTRID^ .
Family Euclypeastrid^, Hseckel, 1866, Generelle Morphologie,

FlBULARINA.
Sub-family Fibulabina, Gray, 1855, Cat. Rec. Echini {emend.).

Echinocyamus.
EcMnocyarmis, Van PheL, 1774, Brief.
Echinocyamus pusillus.

Spatagus pusillus, Miil]., 1776, Prod. Zool. Dau.
Echinocyamus pusillus, Gray, 1825, Ann. Phil., p. 6.

Station 122. September 10, 1873. Lat. 9° 5' S. to 9° 10' S., long. 34° 49' W. to
34° 53' W. ; 350, 120, 32 and 400 fathoms in text. (On label simply. Off Barra Grande
St Thomas.)

REPORT ON THE ECHINOIDEA. 119

Fibularia.
Fibularia, Lamk., 1816, Anim. sans Vert.

Fibularia australis.

Fibularia australis, Desml., 1837, Syn., p. 240.

Station 164. June 12, 1874. Lat. 34° 8' S., long. 152° 0' E. ; 950 fathoms;
bottom temperature, 2 '2° C. ; grey ooze.
Off Port Jackson, 30 to 35 fathoms.

Fibularia volva.

Fibularia volva, Agassiz, 1847, C. E. Ann. Sc. Nat., vol. vii. p. 142.
Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E. ; 28 fathoms;
mud.

ECHINANTHID^.
Sub-family Eohinanthid^, A. Agassiz, 1872, Eevis. EcL, part 2, p. 306.

Clypeaster.

Clypeaster, Lamk., 1816, Anim. sans Vert. (MiiU., emend.),

Clypeaster humilis.

Echinanthtis humile, Leske, 1778, Kl. Add., pL xix. f. A. B,
Clypeaster humilis, A. Agassiz, 1872, Eevis. EcL, part 1, p. 100.

Amboyna ; 15 to 20 fathoms.

Station 212. January 30, 1875. Lat. 6° 55' N., long. 122° 15' E. ; 10, 14 and 20
fathoms ; sand.

Clypeaster scutiformis.

Echinus scutiformis, Gmel., 1788, Linn. Syst. Nat.
Clypeaster scutiformis, Lamk., 1816, Anim. sans Vert,, p. 16.

New Caledonia.

Clypeaster subdepressus (PI. XXXVIIL fig. 22).

Echinanthus subdepressus, Gray, 1825, Ann. PhU., p. 5.
Clypeaster suhdepressut:, Agassiz, 1836, Prod.

OffBahia.

120 THE VOYAGE OF H.M.S CHALLENGER.

Echinanihus.
Eehmanthus, Breyn, 1732, Sdiediasm (emend.).

Echiiianihus testudinarius.

Echinanihus testudinarius, Gray, 1851, Proc. Zool. Soc. I.ond., p. 35.

Station 163. Trawled (label) in 120 fathoms. Off Twofold Bay. April 4, 1874.
Station 161. April 1, 1874. Off entrance to Port Philii). 38 fathoms ; sand.

Lagajstid^.

Sub-family Laganid^, Des., 1857, Synops., p. 217 (emend.).

Laganum.
Laganum, Klein, 1734, Nat. Disp. Ech.

Laganum depressum.

Laganum depressum, Less., 1841, in Agassiz, Mon. Sent., p. 110.

Arafiira Sea.

Station 187. September 9, 1874. Lat. 10° 36' S., long. 141° 55' E. ; 6 fathoms ;
coral sand.

Laganum putnami.

Laganum Putnami, Barn., 1863, in A. Agassiz. Proc. Ac. N. Sc. Phila., p. 359.
Amboyna ; 15 to 25 fathoms.

Peronella (Laganum).
Peronella, Gray, 1855, Cat. Eec. Ech.

Peromelia decagonalis.

Scutella decagonalis. Less., 1827, in Bl., Diet. Sc. Nat. Scut., p. 229.
Peronella decagonalis, A. Agassiz, 1872, Eevis. Ech., pait 1, p. 148.

Station 186. September 8, 1874. Lat. 10° 30' S., long. 142° 18' E.; 8 fathoms;
coral sand. . .

Torres Straits. August 7, 1874.

Amboyna ; 15 to 25 fathoms.

Station 212. January 30, 1875. Lat. 6° 55' N., long. 122° 15' E. ; 10, 14, and 20
fathoms ; sand.

Station 190. September 12, 1874. Lat. 8° 56' S., long. 136° 5'E.; 49 fathoms ;
bottom temperature, 23'9° C. ; mud.

Tongatabu.

REPORT ON THE ECHINOIDEA. 121

Station 173. July 24, 1874. Lat. 19° 10' S., long. 179° 40'E.; 315 to 310 fathoms;
coral. Matuku.

Station 188. September 10, 1874. Lat. 9° 59.' S., long. 139° 42' E. ; 28 fathoms.;
mud,

Station208. January 17, 1875. Lat. 11° 37' N., long. 123° 32' E.; 1 8 fathoms ; mud.

Station 219. March 10, 1875. Lat. 1° 50' S., long. 146° 42' E. ; 150 fathoms ; mud.

Station 192. September 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129 fathoms;
• mud.

Papeete Harbour, Tahiti, 20 fathoms. September 28, 1875.

Peronella peroni.

Laganum Peronii, Agassiz, 1841, Mon. Scut., p. 123, pi. xxiL
Peronella Peronii, Gray, 1855, Cat. Rec. EcL, p. 13.

Station 162. April 2, 1874. Bass Straits, 38 to 40 fathoms; sand.

Off Port Jackson ; 30 to 35 fathoms.

SCUTELLID^.
Family SCDTELLID.E, Agassiz, 1841, Mon. Scut, {emend.).

Echinodiscus.
Ecliinodiscus, Breyn., 1732, De Ecliin. Schedias. (Leske, emend.).

Echinodiscus Icevis.

Mellita Icevis, Klem, 1734, Nat. Disp. Ech.

Echinodiscus Icevis, A. Agassiz, 1872, Revis. Ech., part 1, p. 113.

New Caledonia. .

Mellita.

Mellita, Kloin, 1734, Nat. Disp. Ech. (pars.).

Mellita seocforis.

Echinodiscus sexiesperforatus, Leske, 1778, Kl. Add.

Mellita sexforis. A. Agassiz, 1872, Revis. Ech., part 1, p. 141.

Off Bahia.

Astriclypeus (Mellita).

Astriclypeiis, VerriU, 1867, Notes on Radiata, p. 311.

Astriclypeus raanni.

.dsincZy^jeMs ilfawm', VerriU, 1867, Notes on Radiata, p. 311.

Singisima, Inland Sea, Japan. May 28, 1875.

(ZOOL. CHALL, EXP. PART IX. 1881.) 1 ^°

122 THE VOYAGE OF H.M.S. CHALLENGER.

Encope.

Encope, Agassiz, 1840, Cat. Syst. Eotyp.

Encope ema7'ginata.

Echinodiscus emarginatiis, Leske, 1778, Kl. Add., p. 136.
Encope emarginata, Agassiz, 1841, Mon. Scut., p. 47, pi. x.

Off Bahia 20 to 70 fathoms.

PETALOSTICHA.

Sub-order Petalosticha, Hieckel, 18G6, GenereUe Morphologie (emend.).

Cassidulid.e.

" Family Cassidulid^, Agassiz, 1847, C. E. Ann. Sg. Nat., vol. vii. p. 147.

NUCLEOLID^.

Sub-family Nucleolid*, Agassiz, 1847, C. R. Ann. Sc. I^at., vol. vii. p. 147.

Echinolampas.

EcMnolampas, Gray, 1825, Ann. Phil.

It certainly is very unfortunate for Paleontological nomenclature that both Gray and
myself should have felt compelled to adopt the name Echhianthus for Clypeaster
rosaceus. Desor and D'Orbigny starting from different standpoints, the one in his zeal to
restore the old names of Breynius and the other with the idea of not abandoning names
of types which had become generally recognised among Echinologists, limited Breynius'
genera without any reference to the previous limitations of the same genera suggested by
Gray. Gray's suggestions were completely overlooked by Paleontologists, and the
confusion which might have been avoided has, I fear, been only increased by these subse-
quent attempts to reinstate old genera within limits which were not intended by the
original author. The limitations originally introduced by Gray, dating back as they do to
1825, have fully as much right to recognition as a similar attempt to reinstate the same
old genera within different limits dating from 1855. So that, even granting that it was
• not worth while to attempt to reinstate the genera of Breynius, it was worth while to
take into account the divisions adopted by Gray. But with the insufficient distinctions
now shown to exist between Echinantlms (fossil) and Echinolampas, it may be wisest to
retain Echinolampas alone for the group now known among Paleontologists as Echinan-
thus and Echinolampas.

REPOET ON THE ECHINOIDEA. ' 123

Echinolampas oviformis (PI. XXXVII. figs. 10, 11 ; PI. XXXIX. fig. 12; PI. XLI.
figs. 9, 10 ; PI. XLIII. figs. 3-5 ; PL XLIV. figs. 41-44).

Echinus ovifortnis, Gmel., 1788, Linn. Syst. Nat.
Echinolampas oviformis, Gray, 1825, Ann. Phil., p. 7.

I have figured on Plate XXXVII. the single specimen of Echinolampas collected by
the Challenger. It is interesting as it is still covered wdth spines, while nearly all the
specimens of which I have any knowledge are bleached and denuded of spines. The
spines are remarkably short over the whole of the abactinal surface, they are distant,
slightly swollen at the extremity, and the iutertubercular space between the primaries is
closely pack-ed by minute slender miliary spines. On the actinal surface the spines are
longer and more slender, the miliary spines less numerous ; the spines increase in length
towards' the actinostome and form quite prominent tufts of larger spines over the
bourrelets and in the interambulacral spaces adjoining the actinostome.

The colour of the spines in alcoholic specimens is yeUowish-green. The general fades
of the spines and their arrangement on the test recalls more that of the Clypeastroids
(such groups as the ScuteUidse) than the Spatangoids proper.

Station 192. September 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129 fathoms ;
mud.

Cato^yygns.

Catojjygws, Agassiz, 1836, Prod., p. 185.
*Catopygus recens (PI. XX. figs. 17-21).

Gatopygus recens, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p, 204.

Seen from above (PI. XX. fig. 1 8) the test is ovoid, being broadest posteriorly; the apical
system is anterior, there are three genital pores, the left anterior l^eing wanting ; the
madreporic body is indistinct. In the petaloid ambulacra the exterior pores are comma-
shaped, the interior circular. All the petals are similar in structure, and the anterior
and posterior ambulacral petals are equal in length, while the odd anterior is somewhat
longer. The median posterior interambulacral suture is sunk in a shallow groove
(PI. XX. fig. 18), which gradually deepens towards" the anal system, beyond which
it becomes quite deep (PI. XX. fig. 20) and then gTadually comes to the surface of
the test at the angle of the round beak, forming the extremity of the anal plastron as
is well seen in the end view of the test (PL XX. fig. 20). The summit of the test
corresponds with the apical .system (PL XX. fig. 21), the posterior edge of the test is
regularly rounded, the anterior extremity forming a rounded point by the junction of
the actinal and abactinal curves of the test, where they unite below the extremity of the
odd anterior petal. Seen from the end the outline is heart-shaped (PL XX. fig. 20) with
the rounded anal beak projecting below the level of the actinal surface. The actinal
surface is gibbous, with a nearly central sHghtly sunken actinostome, the phyllodes

124 THE VOYAGE OF H.M.S. CHALLENGER.

are well defined and prominent bourrelets. The anal system is circular, deeply sunken at
the extremity of the wide anal groove.

The only specimens of this species collected were denuded of spines. The whole test
is covered by a uniform granulation much as in PI. XX. fig. 17, formed of the primary
spines with their sunken areolas, and the intertubercular space is closely covered by
minute mdiaries ; the areolas become less sunken towards the actinostome, and the
primaries are also more distant.

The ambulacral pores continue from the petals to the phyllodes in a single row, one
pore to each plate placed close to the lower suture (PI. XX. fig. 17) ; they are not
prominent on the abactinal surface of the test.

Station 192. September. 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129
fathonis ; mud.

Spatangid^.
Family SPATANGiDiB, Agassiz, 1836, Prod. Mon. Ead. (emend.).

POUKTALESI^.

Sub-family Poubtalesi^, Wy. Thomson, 1877, Voyage of the Challenger, Atlantic, vol. i. pp. 376, 396.

From the analysis given of the characters of the genera allied to Pourtalesia proper,
it becomes quite evident that we have to deal with a very remarkable group of Ecliinids,
standing in many respects in striking contrast to other Spatangoids, while possessing
at the same time affinities to other families of the Petalosticlia, and thus showing a close
structural relationship hitherto unsuspected between apparently widely diff'erent forms.
For these reasons it has seemed best to separate this group of Echinids as a new family
from the other Spatangoids, and in this I foUow the suggestion made by Thomson that
these species would probably form a new family characterised by their simple ambulacral
system ; but as I have shown this character, while well marked in Pourtalesia,
Paleopneustes, Echinocrejns, Cystechinus, Aceste, and the like, becomes less apparent in
Genicopatagus, Homolampas and Argopatagus ; and such genera as Aceste and Aerope,
are evidently more closely allied to the Brissina than to the PourtalesiaB, or more
properly Aerope, is an embryonic Brissopsis while Aceste is an embryonic Schizaster.

The course of the alimentary canal in the Pourtalesias seems quite variable. In
Echinocrepis (PI. XXXV." fig. 13), after lea\dng the actinostome the narrow oesophagus
opens into a broader alimentary canal, which extends vertically towards the apical system,
turns back upon itself over the actinostome curving to the left, then sweeps in a horse-shoe
round the edge of the test to the opposite side of the test where ij; forms a reverse loop
to the left (seen from the actinal side) side of the test, and then goes straight to the anal
system as a somewhat narrow intestine. The alimentary canal is supported in its place in
this genus by a few thin mesenteries, and the two main loops are connected by a broad

REPORT ON THE ECHINOIDEA. 125

mesenteric fold somewhat similar to that of Rhynchopygus, but not extending like a
diaphragm across the test. In Spatagocystis, the course of the alimentary canal (PI.
XXVL* fig. 1) is much the same. It is however more free within the test, and not
supported by so many mesenteries. The intestine also opens in the posterior part of the
pouch (PI. XXVI. ^ fig. 5), forming the anal system (PI. XXVI." fig. 6). In Pourtalesia
proper, although the anal system is deeply sunken, there is no such pouch formed, the
plates of the anal system are nearly on a level with the surface of that part of the test
(PI. XXII. fig. 14; PI. XXII." fig. 13; PI. XXVIII." fig. 6; PI. XXXV. » fig. 13). In most
of the species of Pourtalesia proper, the course of the alimentary canal is still less definite,
althouoh havinof in -oreneral the trend of the genera noticed above, as is well shown in the
profile views of two specimens of Po?«taZesia hispida (PL XXII. figs. 10, 11), which have
the rounded alimentary canal of Spatagocystis^ and no prominent mesenteries. The
intestine is well defined in this species (PL XXII. fig. 14) as well as in Spatagocystis
(PL XXVL* fig. 6). Hoffman's organ is present in the Pourtalesise, and is well shown
(PL XXII." fig. 12) in Pourtalesia laguncula. In Pourtalesia ceratopyga we have again
the broad alimentary canal well supported on the test by mesenteries, much broader
even than we find them in Echinocrepis.

The actinostome of the Pourtalesise is elliptical, forming the large opening of the
actinal groove. It is covered by a membrane strengthened by an outer row of plates
(PL XXVIII." fig. 9), from the centre of which leads the narrow cesophagus (PL XXIL*
figs. 12, 15) ; it is not labiate as in Schizaster and allied genera, but the structure
of the actinostome is more closely allied to that of the Spatangoid genera having the
edges of the actinostome in one plane. The structure of the actinal groove is due, as is
well seen in a profile view, to the enormous development of the odd anterior ambulacrum,
the plates immediately adjoining the actinal edge being fully as large or larger than
those of the adjoining interambulacra (PL XXII. figs. 15, 17; PL XXII." fig. 15;
PL XXVIII." figs. 9, 11), while those of the anterior lateral ambulacrum are smaller
and those of the posterior lateral ambulacra immediately adjoining the actinostome are
extremely narrow and elongate (PL XXII." figs. 2, 9 ; PL XXVIIL-fig. 10 ; PL XXXV.-
fig. 10 ; PL XXVI." figs. 2, 4). This is of course in entire opposition to the usual structure
of the actinal region in Spatangoids, in which owing to the position of the actinostome coin-
cident with the general level of the actinal region and the uniformity of the small .size of
the plates of the ambulacral areas immediately adjoining the actinal opening as in Plate
XXXV. figs. 11, 12, and Plate XXXV." fig. 1, and other normal Sj)atangoids, no such difier-
encein the size of the ambulacral plates of the different areas exists. The first trace of this
gradual increase in size of the plates of the odd ambulacral area is well shown in the genus
Cionohrissus (PL XXIII. fig. 9), in which we have a slight actinal groove. We find the

1 In Cystechinus the course of the narrow alimentary canal is more complicated (PI. XXIX."" fig. 6), recallin<,'
somewhat the course it takes in the Desmosticha.

126 THE VOYAGE OF H.M.S. CHALLENGER.

same relative increase in the size of the actinal plates of the odd ambulacrum adjoining
the actiilostome in all the Spatangoid genera in which there is a tendency to form a more
or less distinct actinal groove. In genera allied to the Pourtalesise such as Cysteckinus
and Urechinus, there is a similar increase in the size of the ambulacral plates round the
actinostome (see PL XXIX." figs. 15-18; PL XXIX." figs. 2/5, 6; PL XXX. fig. 14),
but in these genera the actinostome is not vertical but only very slightly sunken below
the general level of the actinal surface.

The whole group of Sj)atangoids to which Pourtalesia, Echinocrepis, CystecJwi^is,
Urechinus, Calymne, &c., belong, are remarkable for the large size of the plates of the
ambulacral areas (see Pis. XXII.^ XXVII. , XXIX.^ XXX., XXXV.^) compared to the size
of the corresponding interambulacral plates.

In Pourtalesia, Cystechinus, Echinocrepis and the genera above mentioned there are
nearly as many ambulacral as interambulacral plates, and with the exception of a little
crowding towards the apical system and at the actinostome, the coronal plates of the two
areas alternate nearly as regularly as if they belonged to the same system (see PL XXII."
figs. 7; 9 ; PL XXVII. fig. 7 ; PL XXIX.^ XXIX.* figs. 1-4 ; PL XXX., XXXV." figs.
9-12, and specially the portions of the ambulacral plates with adjoining interambulacral
plate of Plate XXIX." fig. '7 ; PL XXVIII.^ fig. 14 ; PL XXXV.^ fig. 8).

In all the Petalosticha with petaloid ambulacra, the number of ambulacral plates is
large in the petaloid portion of the ambulacra, and although it decreases, and the plates
become larger from the extremity of the petals towards the actinostome, especially on tlie
actinal surface and mainly in the posterior lateral ambulacra, yet they decrease again
rapidly when adjoining the actinostome, where two or three or even four ambulacral plates
often correspond to a single interambulacral plate of the adjoining area.

In the Clypeastroids the same thing takes place in aU those in which we have petaloid
ambulacra, while it is in such genera as Galerites, Discoidea, Hyhoclypus which have not
petaloid ambulacra proper that the ambulacral plates are more uniform in size.

It is in the Ananchytidse, Dysasteridfe, and the like among the Petalosticha that this
increase in the size of the ambulacral plates takes place, and it is also among the Dysas-
teridse that we find, as in the modern genera allied to Cystechinus, the elliptical actinostome
only slightly sunken below the level of the actinal region.

All these modern Echinids, however much they resemble the Ananchytidse and Dysas-
teridse in general a23pearance, and in the structure of theu- apical system, yet difier
radically in having only simple pores for the passage of the ambulacral suckers, piercing-
each plate near the centre, extending from the abactinal region to the few plates with
double pores near the actinostome which carry the so-caUed gills of the Spatangoids.

In the Petalosticha it is also among the Dysasteridse that the sunken anal groove
makes its appearance in such genera as Metaporhinus,, and among the Ananchytidse in
Cardiaster.

REPORT ON THE ECHINOIDEA. 127

It becomes quite a common feature in many of the genera of the Cassidulidse and the
like; but although it is only in such forms as Pygurus and its allies that there is a tendency
to form an abactinal anal beak covering the anal system, it is mainly among the Spatan-
goids that the actinal anal beak appears as a modification of the subanal plastron or an
indication of its presence in an exaggerated form such as we have it in Pourtalesia proper.

In those Cassiduloid genera in which such a rudimentary actinal beak is formed, the
width of the test is generally greatest at the posterior extremity {Cassididus, Rhyncho-
pygus). An anal groove is indicated early among the Jurassic and' Cretaceous genera
in Pygaster, Clypeus, and Hyhoclypus, and less distinctly among the Discoideae and
Galeritidae, and in the latter there is a trace of an abactinal anal snout as in the modern
Echinocreins or Cystechinus, and Urechinus, while a true actinal groove, although indi-
cated in Dysaster and perhaps in Asterostoma where all the actinal ambulacra are sunken,
is well seen in the Ananchytidae and especially in Infulaster, which by its abnormal outline
recalls to us strikingly the Pourtalesian genus Echinocrepis.

The absence of a fasciole in such genera as Echinocrep>is and CystecUinus, and the pre-
sence of a distinct anal fasciole in Pourtalesia and Urechinus, plainly shows that in the
Petal osticha the earliest fasciole to appear was probably a subanal one, as it seems to
exist in such genera as Urechi?ius in which the anal snout exists in a very rudimentary
form, and in which the subanal shield (PL XXX. fig. 19) is quite faintly indicated.

The subanal fasciole of such Cretaceous genera as Cardiaster and Micrasler, in which
it first makes its appearance among the fossils, would seem to bear out this view.

In Pourtalesia proper I have in the description of the species called attention to the
structure of the apical system, and shown that the four genital plates are with one exce]>
tion in the trivium; and this is well separated from the bivium by the intercalated apical
interambulacral plates. ■ In Cysteckinus the separation is ■difi'erent, two of the genital plates '
(PI. XXXV. " fig. 5) are associated with the bivium and two with the trivium, and the
bivium and trivium are separated by the intercalated apical interambulacral plates. The
same is the case wdth Urechinus (PL XXX. figs. 16, 17).

In Echinocrepis, however, as in Pourtcdesia rosea, the genital plates are contiguous,
and the bivium and trivium are not separated, while in Spatagocystis the apical system
is like that of Pourtalesia proper ; the genital plates are connected with the trivium
(PL XXVI.'* fig. 8), and that is separated from the bivium by the intercalated apical
interambulacral plates.

The many differently shaped species of the genera of Pourtalesise take their outline
from the greater or less development of the difi'erent ambulacral and interambulacral
regions. "The high and short ambulacral and interambulacral coronal plates, nearly of
uniform size, of the anterior portion of the test, combined with a moderate elongation of
the posterior lateral ambulacra and interambulacra, give us such forms as Pourtalesia lagun-
cula, Pourtalesia Jeffrey si, and Pourtalesia miranda; with lower coronal plates in the

128 THE VOYAGE OF H.M.S. CHALLENGER.

anterior region we get forms like Pourtalesia carinata. Witli these lower anterior coronal
plates, combined with a great elongation of the plates, especially of those of the posterior
lateral, interambulacral, and ambulacral areas, we get such forms as Pourtalesia phiale,
while with plates of a uniform size in the different parts of the test we get such conical
forms as Echinocrepis, and when more or less elongate posteriorly, such forms as
Pourtalesia ceratopyga by the elongation of the posterior plates.

In Spatagocystis the arched elliptical test is the result of a large number of hori-
zontally elongated coronal plates, somewhat larger in the posterior region of the test and
of uniform size anteriorly, while the more regular outline of Urechinus is the result
of a greater uniformity in the size of the plates of the anterior and posterior extremities,
which reaches its maximum of regularity in the nearly circular outline of Cystechinus with
its ambulacral and interambulacral areas composed of plates nearly aU of uniform size in
corresponding parts of the test.

The genus EcJiinocrepis seems to form a passage between the Pourtalesise without
an anal snout and such Ananchytid genera as Cystechinus. We readily trace also
how such genera as Nucleolites do not differ so radically as they seem to do at first
sight from genera in which the anal groove is not developed. In fact when we
compare the fossU genera Echinohrissus, Hyhoclypus, Clypeopygus, and the like, with
the Pourtalesise, we' find in the latter family a sunken actinal groove, a feature once
so common among the genera of the Jurrassic and Cretaceous periods. This structure
has become less and less common until we find but few genera in the Tertiary formation
with a sunken anal groove, and at the present time only a few species of Nucleolites
in addition to the Pourtalesise stUl retain the sunken anal groove. This seems in
the Secondary and Tertiary periods to have been a character peculiar to the Echino-
lampadae and their allies. The existence of a deeply-sunken actinal groove or its repre-
sentative is, however, much more prevalent among the recent Spatangoids, and its modifi-
cation from the simple sunken ambulacrum of Asterostoma to the deeply-sunken actinal
groove of Pourtalesia can be easUy traced. It has left its trace in the greater number
of recent Spatangoids in the more or less sunken anterior ambulacral groove. This,
however, in most recent Spatangoid genera is limited to the abactinal .side of the test,
generally disappearing at the ambitus, taking its greatest development in the deeply-
sunken ambulacra of some of the Schizasteridae such as Moira and Schizaster, and forming
a gradual transition, as it were, between the existence of a single deeply sunken anterior
ambulacral groove situated on the actinal side and the more or less sunken petaloid
ambulacra. That is to say, the actinal groove is a modification at the actinal region
of the ambulacra similiar to the sinking of the plates of the apical part of the ambulacra
to form more or less deeply sunken areas ; only the pores remain single, and there is no
modification of the pores forming the petals, indicating a different function, as in the
normal Spatangoids.

REPORT ON THE ECHINOIDEA. 129

In the normal Spatangoids tlie odd interanibulacnim on the actinal surface consists
generally of three large plates, which occupy the whole space between the actinostome and
the edge of the ambitus. In the Pourtalesise and the allied genera, Spatagocystis, Echino-
crepis, Cystechinus, and Urechinus, this odd interambulacrum is made up of a large
number of small plates, none of them having the preponderance in size so marked in the
majority of recent Spatangoids and forming the well-marked actiual plastron of such
genera as Schizaster, Maretia, Metalia, Hemiaster, &c. It is in genera like Palceotropus
and Genicopatagus that the actinal plastron has a somewhat greater prominence till it
becomes in such types as Homolampas, Paleopneustes, and Argopatagus nearly as promi-
nent as in the Spatangoids proper mentioned above. This character of the absence of
a true actinal plastron is characteristic of the Petalostichan genera which retain Clypeas-
troid' or Echinolampan features, and we find it, consequently, wanting in such families as
the Cassidulida3 and Dysasteridaj, while in the Ananchytidas the actinal plastron is a pro-
minent structural feature of the family which gradually becomes more marked in the other
families of Spatangoids.

.The genus Spatagocystis forms the passage l^etween such genera as Holaster, Cardi-
aster, Ananchytes, Infulaster, and Pourtalesia. From above it has somewhat the
general outline of the pointed form of Pourtalesia lagnncula, while the test has the
general appearance of Cardlastcr and Ananchytes combined with the sunken actinostome
of Pourtalesia and the presence of a small anal snout, with the slightly sunken anterior
ambulacral region of Infulaster; while Echinocrepis forms the passage from the
Pourtalesise to such Ananchytid forms as Cystechinus and Urechinus so far as the
structure of the anal system is concerned. The test of Spyatagocystis has neither the
angular outline of Echinocrepis nor the bottle form of Pourtalesia, but has the swollen
rounded contour of Spatangoids like Micraster and Holaster.

The anal snout formed in Sp>atagocystis resembles more the beak in prolongation of the
subanal plastron of some of the Spatangoid genera, such as Echinocardmm and the like.
With the overhanging abactinal hood and the small beak of Sjmtagocystis we readily trace
the passage to such an anal extremity as that of Urechinus and Echinocrepis, in which the
actinal slope forms a more or less bevelled surface with rounded angles to the actinal and
abactinal surfaces, on which is situated the more or less sunken anal system. The pro-
minence of the anal snout plays an important part in deflecting the odd interambulacrum
from its course, or in stopping it even altogether from reaching the actinal surface or dis-
connecting it from the actinal plastron.

In the group of Spatangoids to which we now come, the genera Argopatagus, Homo-
lampas, Genicopatagus, Linopneustes, and Paleopneustes, while having for a part of the

1 The Clypeastroid affinities of the Pourtalesise consist in the simple actinostome and in the structvue of some of the
pedicellariae which are like those of the Clypeastroids and Echinolampadte.

(ZOOL. CHALL. EXP. — PART IX. 1881.) . 1^7

130 THE, VOYAGE OF H.M.S. CHALLENGER.

ambulacra the simple ambulacral pores characteristic of the genera of the Pourtalesise proper,
such as Pourtalesia, Echinocrepis, Cystechinus, Urechinus, and Calymne, differ from these
in having either a labiate actinostome similiar to that of the normal Spatangoids, or in
having a lateral fasciole in addition to the more or less rudimentary sulianal fasciole found
in the latter group. Tbis second group also shows a tendency in the abactinal region to
form rudimentary petals, but in these the tentacles, while passing through paii's of pores,
still retain the simple character found in the Pourtalesise proper.

In Aerope and Aceste the odd anterior ambulacrum takes a great development, the
suckers of that area occuioying in one genus the greater part of the abactinal surface
within the peripetalous fasciole ; in the other the whole of the same space in the sloping
anterior part of the test. This group of Spatangoids brings out the aiiinities of the Pour-
talesiee to such Spatangoids as Brissopsis, Hemiaster, Echinocardium, Lavenia, and the
like.

The group of Spatangoids to which Argopatagus, Homolampas, and Paleopmeiistes
belong, although it has the highly laljLate actinostome so characteristic of the recent
Spatangoids, is characterised by the rudimentary nature of the ambulacra and by the
embryonic structure of the ambulacral and interambulacral plates, that is to say, by their
uniformity in size. This is specially the case in Argopatagus and Genicopatagus, some-
what less in Paleopneustes, while in Homolampas the great difference in the size of the
plates composing the ambulacra and interambulacra brings this genus nearer the typical
Spatangoid in structure ; in Paleopneustes, the closer relationship is indicated by
the tendency to form more or less rudimentary petaloid ambulacra towards the apical
system.

Aerope and Aceste, together with Cionohrissus, form a group of Spatangoids illustra-
ting the affinities of the family Pourtalesise with the Brissina. In Aerope and Aceste
the actinal surface of the test, while having the normal Spatangoid structure of a more or
less weU-developed actinal plastron, yet retains somewhat the cylindrical form of the
Pourtalesise and the simple circular actinostome of this family. The ambulacral system,
although more simple than in Cionohrissus, is surrounded by a more rudimentary, less
distinctly defined peripetalous fasciole ; and we have no trace of any anal snout which is
still a prominent feature in Cionohrissus, and very rudimentary in tlie Brissina proper.
The sunken odd ambulacrum of Aceste, the great development of the suckers of this
ambulacrum in both Aerope and Aceste is a feature with which we had l)ecome familiar
in young Brissina. The presence of a large anal fasciole surrounding the posterior part
of the test is like'^ise a feature characteristic of the young of that family. In Ciono-
brissiis the petaloid system is as greatly developed as in such genera as Brissopsis and Mac-
ropneustes. The affinities developed in so many directions in the group of Pourtalesise is
one of its most interesting features ; and as we have iust traced the relationship of the
Pourtalesise to the Brissina, and to such genera as Hemiaster, Echinocardium, Lovenia,

REPORT ON THE ECHINOIDEA. 131

and the like througli Aerope, Aceste, and Cionohrissus, we can as readily trace the affinities
of the family to the Spatangina proper through such genera as Palaotropus, Genieo-
patagus, and Homolampas, and again to the Galeritidse and Echinolampadge through such
genera as Uy-echiniis and Cystechinus, while the many-sided affinities of the Pourtalesige
to the Ananchytidse, Dysasteridse, and sucli genera as Cardiaster, Holaster, Toxmter, and
the like have been more or less insisted upon in the comparative description of the several
genera of the family.

The fact that this group of Pourtalesise has existed undisturbed since the Chalk, and
has been modified in so many different directions, makes this family one of the most
interesting studies among the Echinids as far as relates to the affinities of the different
groups of Spatangoids ; and their examination has done much to bring out the close
relationship existing between apparently most distant forms in the study of the fossil
genera thus far discovered ranging from the Chalk to the present time.

The Ananchytid and at the same time the Galeritid affinities of the family ai-e best
shown in the structure of Cystechimis, in which we have a slightly sunken actinostome, no
fascicles, a disconnected apical system, the plates of the test of nearly equal size in the
ambulacra and interam1)ulacra, a flat actinal region, a high conical test, and in some species
a tendency in the plates surrounding the actinostome to develop into bourrelets or into an
indistinct posterior labium. Such a genus as Urechinus, on the other hand, although
most closely allied to Cystechinus, strikingly shows much more normal Spatangoid
affinities-; and such a genus as Calymne, while retaining structural features of Cystechinus,
such as the uniform size of the coronal plates in all the areas, has an elliptical test, a
strongly-marked actinal keel, again a most Ananchytid apical system, simple ambulacral
pores, a circular actinostome, and on the other side, the rudiments of a peripetalous
fasciole across the anterior extremity, a feature onty found in those Spatangoids differing
most widely from such genera as recaU the Echinolampadse or Clypeastroids.

Through Homolampas and Argopatagus, which at first glance so greatly re-
semble Spxttangus proper, we can readily trace the relation of the Pourtalesife to the
Spatangina. The simple ambulacral pores, the rudimentary petals, and the compara-
tively large ambulacral plates are Pourtalesian features, while the structure of the
actinal surface, the presence of a subanal and perij)etalous fasciole (in Homolampas
fulva), the great development of some of the primary tubercles, and the jirominently
labiate actinostome, place this genus in close proximity to such genera as Lovenia,
Maretia, Eupatagus, and Metalia.

Genicopatagus, on the contrary, shows most markedly the affinities of the family to
Spatangoids with a prominent labiate actinostome ; to such genera as Holaster, Cardiaster ,
and Toxaster the group becomes allied from the structure of the ambulacral areas above
the ambitus ; while the remarkable affinities of this genus to Paleopmeustes and PalcBO-
tropus, from the structure of the ambulacral petals, as well as the total absence of fas-

132 THE VOYAGE OF H.M.S. CHALLENGER.

cioles, and the large size and small number of the coronal plates in lioth areas, Ijoth on
the actinal and abactinal sides of the test, also show the structural affinities in the
direction of the Ananchytidse and Galeritidse.

It is remarkable that it is among the Dysasteridse ' to which the Pourtalesiee are in
many respects most closely allied, that we also find a very great diversity in the outline of
the test; many species of the CoUyritidEe, such as Dysaster calceolatus, resemble closely
our recent Echiyiocrepis ; others, like Colly rites jaccardi, Des., remind us of Urechinus.
On the other hand such genera as Archiacia, Infidaster, Grasia, and Metaporhimis,
among the extinct genera, show quite as great diversity in shape as we find between
Pourtalesia, Oystechinus and Spatagocystls among the deep-sea types of Pom-talesise.

It is interesting to note the general character of the pedicellarise. Among the
numerous genera of Pourtalesise there is no group of Echinids in which we find so many
difi"erent kinds, and theii- structure Hke that of the spines and of the difi"erent parts of
the test points to the most varied systematic affinities. We find among these the large-
headed pedicellariffi (PI. XLV. fig. 48) of Pourtalesia (PI. XLV. figs. 28, 36), of Cyst-
echinus, of Spatagocystis (PI. XLV. fig. 39), of Genicojmtagus (PL XLV. fig. 21), the
type of Spatangoid pedicellariaj which most closely resembles that of the large-headed
pedicellariae of the Echinidse and Echinometradse'.

We next find the Spatangoid type (PL XLV. figs 20, 20') which in this group seems
frequently modified to assume the more Echinid-like type, of which Pseudoholetia is an
example (PL XLIV. fig. 38), of having one or two large hooks terminating the more or
less narrow prong of the valves as in Pourtalesia (PL XLV. figs. 46, 47, 49, 56, 57, 58).
Or else we have the extremity of the valves varying from the Spatangoid type in becom-
ing more or less cup-shaped (PL XLV. fig. 41) with strong serrations (PL XLV. fig. 43,
Echinocrepis) approaching somewhat the regular crescentic serrations so characteristic of
the Clypeastroids, and which is still more markedly Clypeastroid in Aceste (PL XLIV.
fig. 47). In Cystechinus, and specially in Pourtalesia proper, these Clypeastroid
like pedicellaria3 are very characteristic of the type and indicative of one of the most in-
teresting of the affinities of this Spatangoid group of Echinids, an affinity fully borne out
by a comparison of other structural features. It is specially interesting to note in this
connection that in Echinolampas (PL XLIII. figs. 3, 4 ; PL XLV. figs. 41, 43) these
Clypeastroid like pediceUarise also occur.

Pourtalesia.

Pourtalesia, A. Agassiz, 1869, Bull. Mus. Comii. Zool., vol. i.

In the genus Pourtalesia proper, as 1 have retained it here, there are two groups of
species readily distinguished from the character of the test ; these I was at first inclined

1 The spines of the Dysasteridse, which have been figured by Coster and De Loriol, are similar to those of the
Pourtalesiee.

REPORT ON THE ECHINOIDEA. 133

to separate into distinct sub-genera on comparing such extreme forms as Pourtalesia
miranda, P. laguncula, and P. phiale with such forms as Pourtalesia ceratoijyga and P.
rosea. The former group is distinguished hj the extreme tenuity, almost transpar-
ency, of the test and its more or less bottle-shaped outline, while the latter group con-
tains species with a flattened test, a triangular outline from above and a comjjaratively
thickened test.

On examining, however, the group of Pourtalesise to which Pourtalesia hispida,
P. carinata, and P. jeffreysi belong, the impossibility of maintaining this arbitrary
division becomes at once apparent.

• Pourtalesia hispida, while having the general appearance of Pourtalesia miranda,
has a much thicker test, and in Pourtalesia carinata we have a stout test and a pro-
minent snout, with a posterior apex, and the closer tuberculation of the group to which
Pourtalesia rosea and P. ceratoj^yga belong. It is remarkable how great is the variation
in the extent of the separation of the bivium and trivium at the apical system in the
difi^erent species of the genus.

In Pourtalesia rosea the genital plates join the ocular plates of the bivium (PI. XXII.*
fig. 6), in Pourtalesia laguncula, P. hispida, P. ceratopyga, P. cari7iata and P. Jeffrey si
the plates of the posterior lateral interambulacra extend entirely across between the bivium
and trivium, completely separating them (Pis. XXII. fig. 19; PI. XXII.* fig. 10; PI.
XXVIII. figs. 11, 12 ; PI. XXVIII." fig. 12).

I have to add as one of the generic characters of Pourtalesia the existence of a
well-developed subanal fasciole, which in some of the species forms a broad band round
the anal snout.

* Pourtalesia carinata (Pis. XXVII.% XXXVIII. figs. 30, 31 ; PL XLI. figs. 49-52;
PI. XLII. figs. 24, 25 ; PI. XLIII. figs. 20-23 ; PL XLV. figs. 46-52).
Pourtalesia carinata, A. Agassiz, Proc. Am. Acad., vol. xiv. p. 205.

This is a large species with a comparatively stout test. It resembles in outline Pour-
talesia miranda, but is more gibbous, with a more regularly-sloping anterior extremity (PL
XXVIII." fig. 2), which brings the apex more posteriorly than in that species. The
greatest breadth of test seen from above is also more posterior (PL XXVIII." fig. 1). The
primary spines are more numerous on the median interambulacral line of the abactinal
side of the test on the anterior and on the odd interambulacra. The rest of the test is
quite thickly covered with small secondary spines increasing in size towards the ambitus,
and on the actinal side the keel, of the plastron carries still larger primary spines on
tubercles closely packed on the ridges of the line of the actinal keel (PL XXVIII." fig. 8),
and also crowded on the actinal part of the anterior interambulacra and on the inter-
ambulacral plate near the anal snout (PL XXXVIII." figs. 3, 4). The greatest height of the
test is posterior, the apex not corresponding with the apical system. The subanal fasciole

134 THE VOYAGE OF H.M.S. CHALLENGER.

is regularly marked and rather narrow (PI. XXVIIL* figs. 3, 4). The primary spines are
only slightly curved and flaring, generally uniform in width on the sides, but below flaring
and club-shaped. There are four well-marked genital pores (PL XXVIII." fig. 12) situated
in the trivium, which is well separated from the bivium. The genital organs are short
clusters (PL XXVIII." fig. 13) of from seven to eight large purse-like pouches, which do
not apparently ramify like the ovaries of Pourtalesia lagimcula. The madreporic body
is insignificant.

This species, while having the outline of Pourtalesia miranda, P. laguncula, and P.
jeffreysi, has the stout test and close tuberculation of Pourtalesia ceratopyga. The actinal
groove is comparatively smaller, shallower, and narrower than in those species, and the
slight re-entering angle formed hj the anterior extremity when seen from above, and
the more sloping anterior extremity form a passage between the bottle-shaped forms
like Pourtalesia miranda, and the triangular types with posterior apex like Pourtalesia
cerat02)yga.

The actinal and abactinal lines of the snout are nearly parallel, forming a sharp angle
at the abactinal extremity. The anal groove is short and deeply indented. Judging from
the size of some of the fragments of the test of this species, it must have attained a length
to from 90 to 100 mm.

The colour of the test in alcoholic specimens is of a light claret, the whitish-pink spines
standing out in relief upon the dark background. The colour of the test is often darker
on the abactinal keel and on the anterior median interambulacral ridges of the abactinal
side of the test.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. ; 1600 fathoms ;
bottom tempei'ature, 0"8° C. ; globigerina ooze.

Station 157. March, 3, 1874. Lat. 53° 55' S., long. 108° 35' E. ; 1950 fathoms;
diatom ooze.

Station 298. November 17, 1875. Lat. 34° 7' S., long. 73° 56' W. ; 2225 fathoms;
bottom temperature, 1 "3° C. ; grey mud.

*Pourtalesia ceratopyga (Pis. XXVIII. XXXV." fig. 17 ; PL XLI. figs. 44-46 ;
PL XLIL figs. 17-23; PL XLIIL figs. 15-17; PL XLV. figs. 53-59).

Pourtalesia ceratopyga, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 205.

Nearly complete specimens of a large Poiw'ia^esm which were brought up from 2225
fathoms at Station 298, form, with Pourtalesia rosea, an entirely distinct group from the
other species collected. This species is remarkable for the great breadth (PL XXVIII.
fig. 1) of the anterior extremity, with the re-entering median ambulacral region extending
laterally so as to form a rounded angle with the sides; this part of the test is by far the
widest, and it slopes very rapidly towards the posterior extremity. The width of the anal
snout is proportionally smaller than in the other species of the group ; the sunken actinal

REPORT ON THE ECHINOIDEA. 135

groove is narrow, and the actinostome not very distant from the anterior edge ; the test
is comparatively low (PI. XXVIII. fig. 2), with a large number of primary tubercles
quite uniformly scattered over it (PL XXVIII. fig. 10), except along the actinal keel
where they are somewhat larger (PI. XXVIII. fig. 7). The test is thin but hard and solid,
the subanal fasciole is large and broad (PI. XXVIII. figs. 5, 7), and the number of plates
comprised in the test is greater than in other species. The spines of this species are
proportionally short and stouter than in the other species of the genus. The whole test
is moderately covered with small secondary and miliary spines.

There are four genital openings, three larger than the fourth (the left anterior), which
is quite rudimentary; they are situated in the trivium, well separated from the bivium by
the lateral ambulacral plates (PI. XXVIII. fig. 12). The anal snout is seen in profile
(PL XXVIII. fig. 2.), angular, separated from the test on the abactinal side by a deep,
sharp cut. The test seen in profile is quite flattened (PL XXVIII. fig. 2), regularly arch-
ing anteriorly, the actinal curve slightly re-entering at the actinostome and convex again
towards the anal snout, the abactinal curve very slightly arched towards the posterior
extremity, suddenly falling towards the deep notch separating the anal snout from the
posterior part of the test.

The apex and apical system are not coincident, the apex being posterior and the
apical system anterior. Immediately adjoining the actinal groove the anterior part of
the actinal surface is quite flat (PL XXVIII. figs. 6, 8). Seen from the anal extremity
the outline is triangular with rounded angles (PL XXVIII. fig. 4),' with a sUght pos-
terior actinal keel (PL XXVIII. fig. 7) to which the anal snout is joined like a button.
The outline when seen from the anterior end is also triangular, but with a re-entering
angle gradually sloping from the flattened anterior actinal surface to the sunken actinal
groove (PL XXVIII. fig. 3). The specimens in alcohol were of a dark claret coloui- at
first, but they have gradually faded out to a light violet tint.

The largest specimen collected measured 98 mm. in length, but fragments of the
anterior extremity of the test indicate that this species must attain nearly double that
length.

Both this species and Pourtalesia rosea are characterised by the absence of prominently-
marked keels, formed by the concentration of primary tubercles on the abactinal median
interambulacral space of the lateral anterior ambulacra and of the posterior abactinal inter-
ambulacrum.

Station 157. March, 3, 1874. Lat. 53° 55' S., long. 108° 35' E. ; 1950 fathoms;
diatom ooze.

Station 298. November 17, 1875. Lat. 34° 7' S., long. 73° 56' W. ; 2225 fathoms ;
bottom temperature, 1"3° C. ; grey mud.

Station 299. December 14, 1875. Lat. 33° 31' S., long. 74°43'W. ; 2160 fathoms;
bottom temperature, 1'1° C. ; grey mud.

136 THE VOYAGE OF H.M.S. CHALLENGER.

*Pourtalesia hispida (PI. XXII. figs. 6-19; PL XXXIX. figs. 34, 36; PI. XLI.
figs. 47, 48).

Pourtalesia hispida, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 204.

This species mainly difi'ers from its nearest ally, Pourtalesia jeffreyd, AVy. Thomson,
in having a shorter anal snout, a more flattened actinal surface, a smaller actinal plastron,
and a smaller number of larger primary tubercles arranged in horizontal rows across the
primary plates. Its outline is more rectangular anteriorly, and more nearly vertically
truncated.

Seen from above (PI. XXII. fig. 7), the sides of the test are nearly parallel, wdth very
slightly re-entering sides, the anterior edge of the test is at right angles with the sides,
and the posterior part of the test is conical with a small rounded snout.

The primary spines are arranged in distant rows of three or four along the sides of
the test (PI. XXII. fig. 6); they are quite short, stout, sharp, more crowded along the
abactinal keel, and are still more numerous immediately above the anal system (PI. XXII.
figs. 7, 9, 12). The anterior slope of the test carries small closely-packed miliaries
(PI. XXII. fig. 13), except on the edge and in the deeply-sunken actinal groove where
the spines are large and closely packed (PI. XXII. fig. 8), extending across the actinal
groove on the actinal side. The primary spines are also more numei'ous on the rounded
keel formed by the anterior interambulacral areas (PI. XXII. fig. 8), and most closely
packed on the small actinal plastron. The rest of the broad flat actinal surface carries
distant irregularly-arranged primary spines. The rest of the test carries but few miliaries
or secondaries. Seen in profile the anterior extremity is nearly vertically truncated and
rounded anteriorly, the apical system and apex corresponding. The line of the actinal
surface is nearly flat, curving upwards to form the lower edge of the anal snout. The
abactinal line is also regularly arched, but falls suddenly above the anal opening and is
indented where it forms the abactinal line of the anal snout (PI. XXII. fig. 6, 9). This
is less developed than in any other species of the genus Pourtalesia. The subanal
fasciole is not clearly defined, it extends round the sharp anal snout as a broad band of
miliaries with ill-defined edges, both exterior and interior.

Seen from the anal extremity, the anal system is placed in a deep triangular pit with
rounded sides (PI. XXII. fig. 12).

There are in this species four genital openings (PL XXII. fig. 19), each connected
with a well-developed genital pouch (PL XXII. fig. 18). The four genital openings are
situated in the trivium (PL XXII. fig. 19), and this is well separated from the bivium by
supplementary interambulacral plates. In alcohol the colour of the test is of a greyish-
pink, the spines of a lighter tint ; at the base of the .spines the test is of a darker colour
forming a deep patch which extends to the miliary ring. Both in this species and in
Pourtalesia phiale, the primary spines are comparatively short, sharp, and stout, and are
quite regularly arranged over the surface of the test.

REPORT ON THE ECHINOIDEA. 187

The sunken actinal system is proportionally larger, the actiual plastron is flatter,
and when seen in profile the test is not as distinctly keeled above and below as in
Pourtalesia miranda.

Pourtalesia miranda, P. laguncxda, P. Jeffreys! , and P. hispida, as well as P. phiale,
are characterised by an extremely delicate, thin, and more or less transparent test ; in
these species we have the outline of the test passing from that of an elongate bottle-
shape to a rectangular form with round corners and a pointed extremity, then to a
triangular flattened test with a prominent anal snout, as in the group to which Pour-
talesia rosea and P. ceratopyga belong, till we come to the typical Echinocrepis on the
one side, or pass on the other hand through the more globular and cylindrical forms such
as Pourtalesia carinata to Spatagocystis and finally to Cystechinus.

The largest sj^ecimens collected, judging from some fragments, must have measured
55-60 mm. in length ; the smallest about half that length.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. ; 1600 fathoms ;
bottom temperature, 0"8° C. ; globigerina ooze.

Station 156. February 26, 1874. Lat. 62° 26' S., long. 95° 44' E. ; 1975 fathoms ;
diatom ooze.

^Pourtalesia laguncula (PI. XXIL» figs. 7-15 ; PI. XXXI. figs. 1-11 ; PI. XXXIX.
fig. 35 ; PI. XL. figs. 61, 62 ; PI. XLI. fig. 53 ; PI. XLIII. figs. 18, 19).
Pourtalesia laguncula, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 205.

This species is closely allied to Pourtalesia miranda ; it is, however, more bottle-
shaped (PI. XXXI. figs. 1, 2), comparatively broader at the anterior extremity, shorter,
with a wide anal snout, and a more vertically truncated anterior extremity (PI. XXXI.
fig. 3), a shorter actinal plastron with larger primary tubercles and a very broad fasciole
round the anal snout (PI. XXII." figs. 7, 9; PI. XXXI. fig. 4). This fasciole I did not
detect in Pourtalesia miranda, and as the unique specimen is in the hands of Professor
Lov^n at this moment of writing, I am unable to give its position, which in the drawing
(Revis. Ech., pi. xviii. figs. 6, 7), seems to run more on the abactinal side of the snout
towards the anal system than in this species. On the actinal surface (PI. XXXI. fig. 1)
the primary tubercles are few in number, distant, and extend on the sides of the test
mainly towards the anterior extremity (PI. XXXI. fig. 1), from the ambitus to the apical
system ; there are from two to three to each plate (PI. XXII. " figs. 7, 9). The primary
spines are generally slightly curved, cylindrical, tapering very slightly or club-shaped,
more thickly crowded in the actinal groove. The whole test is more or less thickly
covered by minute club-shaped miliaiy spines.

The ambulacral tentacles of the odd ambulacrum are large, thick (PI. XXXI. figs. 2,
6), pointed, and quite prominent from the apex until they pass into the actinal groove.

In nearly all the specimens which were broken, so as to admit of a view of the interior

(ZOOL. CHALL. EXP. PART IX. — 1881.) I 18

138 THE VOYAGE OF H.M.S. CHALLENGER.

of the test, the genital organs are well developed, the long genital glands (PI. XXII.*
fig. 14) branch into fine ramifications extending far towards the anal extremity.

In alcohol the colour of the test of this species is light violet or ash coloured,
becoming quite dark towards the abactinal keel and along the anal plastron, as well as
at the anterior extremity.

The younger specimens of this species show considerable variation in the outline
(PI. XXXI. figs. 7-9). They are more triangular when seen from above, less bottle-
shaped, the anal snout more pointed, and when seen in profile (PL XXXI. figs. 10, 11)
the snout is not yet separated from the test by the deep re-entering angle so marked in
older stages. The actinal groove is also proportionally much wider and larger. Seen
from the actinal or anal end (PI. XXXI. figs. 5, 6), the outline is much less heart-shaped
than in Poui^talesia miranda, the rounded outline of the actinal surface projecting
further beyond the general level of the test than in Pourtalesia miranda. The younger
stages of Pourtalesia laguncula resemble somewhat Pourtalesia j^hiale, in which the
anal snout is remarkable on account of its closer connection with the anal part of the
test, compare Plate XXXI. figs, 7-9 with Plate XXIL* figs. 1, 2.

In Pourtalesia his^yida we have also a somewhat pointed anal snout, but much
shorter than in the young specimens of Pourtalesia laguncula, the proportions of the
anal snout and its mode of connection with the posterior extremity of the test seem
subject to very considerable variations ; some of the specimens with narrow anal snout
characteristic of the smaller specimens measuring from 12-16 mm. were nearly 19 mm. in
length. This is quite a small species, the largest specimen measuring only from 22-25 mm.

Station 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' E. ; 800 fathoms;
bottom temperature, 3'9° C. ; mud.

Station 168. July 8, 1874. Lat. 40° 28' S., long. 177° 43' E. ; 1100 fathoms;
bottom temperature, 2"0° C. ; grey ooze.

Station 169. July 10, 1874. Lat. 37° 34' S., long. 179° 22' E. ; 700 fathoms;
bottom temperature, 4*2° C. ; grey ooze.

Station 232. May 12, 1875. Lat. 35° 11' N., long. 139° 28' E. ; 345 fathoms;
bottom temperature, 5'0° C. ; sandy mud.

Station 244. June 28, 1875. Lat. 35° 22' N., long. 169° 53' E.; 2900 fathoms;
bottom temperature, 1*2° C. ; red clay.

Pourtalesia 2}hiale (PL XXII. figs. 1-5 ; PL XXII.-'' figs. 1, 2).

PourMesia pliiale, Wy. Thomson, 1873, Deptlis of the Sea, p. 90; Trans. Roy. Soc, 1874, voL
clxiv., part 2, p. 749, pi. Ixx. fig. 11.

Thomson has only given a very short description of this species in the Echinoidea of
the " Porcupine " Expedition.' I have given on Plate XXL" figs. 1, 2, two figures of this

1 Wyville Thomson, 1874, Trans. Roy. Soc, vol. cLxiv., part 2, p. 749.

REPORT ON THE ECHINOIDEA. 139

species, showing the great elongation of the plates of the test which give it its peculiar
appearance. The subanal fasciole is broad, well-marked, and the actinal gi-oove a rather
shallow triangularly shaped depression with steep sides (PI. XXII. " fig. 2). In general
outline it resembles a very elongated Pourtalesia miranda, and I was at first inclined to
regard it as the young of that species. The young specimens of Pourtalesia laguncula
collected by the Challenger, seem, however, to leave no doubt regarding the distinct
specific characters of this species. Seen endwise, the outline of the test is nearly
elliptical (PL XXII. figs. 4, 5) from the two prominent actinal and abactinal keels,
which project beyond the general level of these surfaces. Seen from the actinal end
(PI. XXII. fig. 4), the actinal gi'oove occupies nearly the whole of the section of the test.
As in Pourtalesia laguncula the primary spines are irregularly scattered over the test,
and are not specially crowded along the abactinal ridge. The apex of this species is
posterior (PI. XXII. fig. 2 ; XXII." fig. 1), and it is remarkable also for its convex
actinal surface, so shaped that the greatest convexity is about half-way from the anal
snout to the anterior end. Seen from above, the anterior extremity has more the shape
of that of such Pourtalesise as Pourtalesia ceratopyga, but is remarkable for the great
size of the actinal grove which forms a huge triangular depression (PL XXII.'' fig. 2 ;
PL XXII. fig. 1), occupying the whole anterior extremity of the test, on the somewhat
flattened actinal surface. The anal snout is also somewhat more flattened than in the
other species of Pourtalesiae, more as we find it in Pourtalesia rosea. The outbne of the
test, when seen from the actinal side is bottle shaped, with deeply convex sides near the
anterior extremity (PL XXII. fig. 1 ; PL XXII.'' fig. 2), widest about half-way between the
anterior extremity and the snout, and gradually sloping towards the posterior extremity.
The abactinal surface slopes very gradually from the apex towards the anterior extremity,
forming a slightly concave line before reaching the anterior edge. It slopes c^uite abruptly
towards the level of the anal snout (PL XXII.'' fig. 1). Both the actinal and abactinal
keels of this species are quite prominent (PL XXII. figs. 1, 3). The excessive elonga-
tion of the odd interambulacral end of the lateral posterior interambulacral and ambu-
lacral areas, gives to this species its greatly elongated shape (PL XXI I." figs. 1, 2).

Pourtalesia phiale seems to be a comparatively small species ; the specimen collected
by the Challenger measured 18 mm. The test is extremely thin. In alcohol it is of a
light yellowish-pink colour, the spines of a darker tint.

Station 156. February 26, 1874. Lat. 62° 26' S., long. 95° 44' E. ; 1975 fathoms ;
diatom ooze.

^Pourtalesia rosea (PL XXII.'' figs. 3-6).

Pourtalesia rosea, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 206.
Fragments of a delicate pinkish Pourtalesia were brought up from Station 272 ;
they must have belonged to a large species closely allied to Pourtalesia ceratopyga, and

140 THE VOYAGE OF H.M.S. CHALLENGER.

probably as large. It differs from that species, however, in ha\'ing an anal snout (PI. XXII.*
figs. 3-5) not so well separated from the test as in Pourtalesia ceratojiyga and other
Pourtalesife, l^ut much like that of Pourtalesia lyhiale, only the fasciole extends from the
anal surface on the edge of the snout towards the anal opening ; the snout is angular
(PL XXII." fig. 3), truncated vertically posteriorly, quite flattened laterally. The few
primary spines present near the abactiual system were large, curved, cylindrical ; the
smaller secondary ones somewhat club-shaped. There were fragments of the ovaries
which seemed long, slender, branching filaments, like those of Pourtalesia laguncula.

This species is also remarkable for not having, as in other species of the genus, its
apical system divided by the encroachment of the posterior lateral ambulacra into a
bivium and trivium (PI. XXII. * fig. 6).

The tuberculation of this species, and the shape of the test, must have been very
similar to that of Pourtalesia ceratoi^yga.

Station 272. September 8, 1875. Lat. 3° 48' S., long. 152° 56' W. ; 2600 fathoms ;
bottom temperature, 1'0° C. ; radiolarian ooze.

*»Spa tagocijstis.

Sjpatagocystis A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 206.

Test ovoid, actinal region flattened, the anteriorly prominent actinal keel extending
to form an anal snout, the abactinal region of the test regularly arched, the anterior and
posterior extremities rounded, the actinal groove sunken. In the apical system, the
genital plates connected, placed in the trivium, separated from the bivium by the inter-
calated interambulacral plates.

This genus has, like Pourtalesia proper, a deeply sunken actinal groove. Its
outline recalls, however, when seen from aljove, the Holasteridae, and forms the transition
between the slightly keeled Holasteridae, and types with more prominent keels extending
into a short and small anal snout, which is so highly developed in Pourtalesia proper.
The anal groove is sharp, and shows how readily among the Holasterid^ we can pass
from a slightly sunken anal system, forming but an unimportant depression on the anal
extremity of the test, as in Toxaster and some of the Dysasteridse, to a somewhat more
sunken system as in Cardiaster, until we pass on the one side to a well-defined anal
groove, as we find it in Metaporhinus, and on the other side to a similarly clearly defined
anal groove, forming a deep re-entering angle in the posterior extremity above the small
anal snout, a mere beak as it were, formed by the prolongations of the actinal keel
beyond the level of the outfine of the test of the posterior extremity. The coronal plates
are of a much more uniform size, both in the ambulacral and interamljulacral zones, and
assume somewhat the regular arrangement so characteristic of Cysteckinus, in which the
Galeritic type of coronal j^lates is still quite prominent.

In some of the Pourtalesise already, such as Pourtalesia ceratoi^yga, and to a certain

EEPORT ON THE ECHINOIDEA. 141

extent even in Pourtalesia laguncula, the posterior interambulacral zone on the abactinal
surface between the apical and the anal system is composed of nearly hexagonal plates,
increasing very gradually in size from the abactinal system to the anal system. This
uniformity of the plates is, however, in Pourtalesia entirely limited to the odd posterior
interambulacrum, while in Spatagocystis the plates of the other zones become more
uniform in size. This structural feature is also connected with the decrease in size
of the actinal groove, as seen from Spatagocystis, Echinocrepis, Urechinus, and
Cystechinus. The plates of the actinal plastron between the actinostome and the
anal snout are also far less elongate than in Pourtalesia proper, though these plates
are evidently the first to become diflferentiated, and appear to be the first trace of
a passage between the Galeritidse and the Spatangidse proper, as far as we can trace
this from the fossil genera. It is interesting in the recent Pourtalesise to compare
the actinal plastrons of such genera as Pourtalesia, Echinocrepis, Spatagocystis, and
Cystechinus, in connection with that of the Dysasteridse, Galeritidse, Hemiasteridaj,
and Spatangina proper. Subanal fasciole indistinct.

'^Spatagocystis ehallengeri (Pis. XXVI. ; XXVI.'' ; XXXIX. fig. 37; PI. XLI.
fig. 40; PL XLII. figs. 10-12 ; PI. XLV. figs. 37-43).

Spatac/ocystis Challengeri, A. Agassiz, 1879, Proc. Am. Acad,, vol. xiv. p. 206.

The outline of the test seen from above (PI. XXVI. figs. 3, 9) is regularly ovoid, slightly
indented anteriorly, in profile arched, faUing towards the posterior extremity (PI. XXVI.
fig. 1), and quite abruptly truncated anteriorly. The actinal floor is flattened anteriorly,
with a prominent keel extending from the actinostome to the extremity of the anal snout
(PI. XXVI. figs. 1,2), the ambitus gracefully arched. The test is thin, quite brittle.

AU the specimens collected as well as the fragments of tests were of a pinkish-violet
tint. The genital organs consist of large yellowish clusters hanging far down from' the
abactinal region by long slender ducts, the diflerent clusters of the genital organs quite
distinct. The lateral interambulacra are very broad (PI. XXVI.'' fig. 9), the coronal
plates are broad, and carry primary tubercles (PL XXVI. " figs. 2, 4, 12, 15, 16) uniformly
scattered over them, carrying fine slender spines (PL XXVI. figs. 1-5). The whole test
closely covered with miliary and secondary spines.

On the actinal surface the spines are somewhat larger (PL XXVI. fig. 2) ; the
actinostome is small and deeply sunken (PL XXVI. fig. 2 ; PL XXVI." fig. 2). The
edges of the deeply-sunken actinal groove are quite well defined on the actinal side,
the groove resembles the elliptical anal groove of Echinohrissus. Like the anal groove
of some species of that genus it does not run indistinctly into a broad groove, and is
limited to one side of the test.

In Pourtalesia proper the actinal groove passes very gradually into a broad anterior
groove, which occupies the greater part of the anterior extremity of the test, while in

142 THE VOYAGE OF H.M.S. CHALLENGER.

SjxUagocystis the actinal groove is limited to the actinal surface (PI. XXVL* fig. 2), and
the extension of the actinal groove from the actinal side over the ambitus to the aljactinal
side forms but a slight indentation in the anterior part of the test (PI. XXVI. fig. 3).

There is a small anal snout (PI. XXVI. fig. 1 ; Ph XXVI." figs. 11, 13, 15, 16), with
a sharp beak extending below the anal system ; there is no trace of a well-defined fasciole,
but there are miliary tubercles closely packed at the tip of the snout on the lower side
(PI. XXVI.^ fig. 12), these correspond undoubtedly to the distinct sub-anal fasciole
encircling the anal snout of Pourtalesia proper. This fasciole, while very distinct in
some species of Pourtalesia, is somewhat iU-defined in others, and thus readily passes
into such an indistinct accumulation of miliaries as we find in Spatagocystis, where
it forms the first trace of the sub-anal fasciole of the group. The anal pouch
(PI. XXVI." fig. 6) is much shallower than in Pourtalesia proper.

The test seen facing the posterior extremity (PI. XXVI. fig. 5) shows how prominent
the keel formed by the prolongation of the actinal plastron has become. The test is
regularly arched, and nearly as gil^bous on the actinal side (with the exception of the
somewhat flattened anterior extremity) as on the abactinal side.

Seen facing the anterior extremity the sunken actinal groove is seen to extend but
little into the anterior part of the test above the ambitus (PI. XXVI. fig. 4).

The extremity of the anal snout barely extends in the largest specimens collected
(PI. XXVI. fig. 1) as far out as the line of the abactinal hood over the anal system
(PI. XXVI.^ figs. 15, 16). In young specimens which are more elongate (PI. XXVI.
figs. 8, 9) and more pointed posteriorly, the actinal keel is exceedingly prominent when
seen in profile (PI. XXVI. fig. 7), projecting beyond the line of the abactinal hood of the
anal system. In these younger specimens the beak is also more limited to the posterior
area, and the test is more flattened on the actinal side, and less gibbous as is v?ell showni
in the figures seen from the anal or actinal extremity (PI. XXVI. figs. 10, 11).

This species is remarkaljle for the great length of the narrow j)lates composing the
posterior lateral interambulacra (PI. XXVI. * figs. 15, 16) and the anterior zone of the
posterior lateral ambulacra ; the width of the other areas forming the sides of the test
is more uniform (PI. XXVI. " fig. 9), the median odd interambulacral zone which forms
the crest of the rounded part of the abactinal region of the test is very narrow (PI. XXVI."
fig. 17), and is composed of plates of nearly uniform size extending to the abactinal region
of the anal hood (PI. XXVI.-'' figs. 10, 17). This is flanked by one row of rather
smaller ambulacral plates forming the posterior zone of the lateral posterior ambulacra ;
in fig. 10 the outer plates should be perforated by the pores, and not the median rows
of plates, which are the plates composing the odd interambulacral zone (PI. XXVI.''
fig. 17). The anterior zone of the lateral j)osterior ambulacra is composed of wider plates
(PL XXVI." fig. 15). The apical system corresponds to the apex placed anteriorly ; there
are three genital pores, the macLreporic body is distinct ; there are four genital plates

REPORT ON THE ECHINOIDEA. 143

adjoining, placed within the trivium and separated from the bivium by the intercalated
interambulacral plates (PI. XXVI." fig. 8).

The anal pouch (PI. XXVI/ figs. 5, 6) is as in the Pourtalesise strengthened by large
irregularly-shaped rectangular plates, and is somewhat triangular when seen from above
(PI. XXVI. * fig. 7) ; the opening is well covered by rather stouter spines than are found
on other parts of the test. Figs. 2, 4, 7, 12 of Plate XXVI." show the arrangement of
the plates of the actinal surface of the test, and a combination of the figures 8, 9, 15, and
17, that of the abactinal side of the test.

The course of the alimentary canal is easily traced in the view of the interior
(PI. XXVI.'' fig. 1) from the actinal side, and in the profile of PI. XXVI. fig. 6. The
course and the shape of the aHmentary canal is similar to that of Cystechinus. The anal
extremity of the canal is remarkable for its small size (PI. XXVI. " fig. 6).

The largest and the smallest si^ecimens collected are figured natural size on Plate
XXVI. The collection also included a couple of intermediate sizes.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. ; 1600 fathoms ;
bottom temperature, 0"8° C. ; globigerina ooze.

Station 157. March 3, 1874. Lat. 53° 55' S., long. 108° 35' E. ; 1950 fathoms;
diatom ooze.

*£Ichinocre2yis.
Echinoerepis, A. Agassiz, 1879, Proc. Am. AcaJ., vol. xiv. p. 200.

This genus has, like Pourtalesia, a sunken actinal groove, but the other features of the
test difi'er entirely from those of the sjoecies thus far described in this family. There is
no anal snout, the anal system though forming a re-entering pouch much as in Pourta-
lesia is situated on the actinal side as in Cystechinus. Seen in profile the test is
pyramidal (PL XXVII. fig. 3), the apical system is placed about one-third the length of
the test from the anterior end ; the anterior part of the test forms a regularly inclined
surface sloping rapidly from the apex to the ambitus with sharply rounded corners ;
towards the actinal surface and at the median line of the lateral anterior ambulacrum on
the upper part of the test, the actinal groove forms a comparatively slight depression
on the actinal surface of the anterior edge of the test, but omng to the gradually sloping
sides of the edge of the actinal groove, extending from the flat actinal anterior part of the
test (PI. XXVII. figs. 5, 7), and taken in connection with the flat sloping test of the
anterior extremity and its deep re-entering angle when seen from above, it forms, when
seen from the anterior extremity, a groove deeply cut out of the test. As seen from
above the anal keel forms a slight arch from the apex to the anal extremity. The median
line of the anterior lateral ambulacra is slightly re-entering, forming a deep indentation
in the anterior outline of the test as seen from above.

The very slight re-entering angle of the median line of the posterior lateral aml)u-

144 THE VOYAGE OF H.M.S. CHALLENGER.

lacra does not extend beyond the ambitus. These deflections give the test an angular
outHne when seen from above (PI. XXVII. figs. 1, 2; PL XXXV.^ figs. 9, 10), the
median interambulacral spaces bulging beyond the general outline. The sides of the
test slope similarly to the anterior extremity from the apex to the ambitus ; the median
ridge connecting the posterior planes is quite rounded and passes into an arched surface
above the anal system, while the junction of the lateral planes of the test, and the
flattened anterior extremity form quite well-marked slightly-rounded angles corresponding
to the outer edges of the anterior extremity of the test (PI. XXVII. figs. 1, 3; PI.
XXXV. ^ figs. 9, 11). The general trend of the outline of the test as seen from above
tapers very gradually towards the anal extremity from the anterior edge of the test
(PI. XXVII. figs. 1,2; PI. XXXV. figs. 9, 10) to the line of the lateral posterior interam-
bulacra ; here it bulges out somewhat, and from the median line it slopes more rapidly to
the anal end, which terminates in a rounded point.

The plates composing the test of this genus are, as in Simtagocijstis, far less elongate
than in Pourtalesia proper. The plates of the actinal surface, especially those of the
lateral ambulacral and interambulacral zones (PI. XXXV.* fig. 10), being elongate, while
on the abactinal surface above the ambitus the coronal plates arc comparatively quite
uniform in size (PI. XXX V.'^ figs. 9, 11, 12) and more or less hexagonal. The arrange-
ment of the plates of the abactinal side of the test in Spatagocystis is very similar to that
oi Echinocrepis, but in the former genus there is a more marked difi"erence between the size
of the plates of the anterior and posterior halves of the ambulacral and interambulacral
zone than we find in the latter genus. The elongated plates forming the actinal surface of
these genera do not seem to be due to the more elongate shape of the test, for in genera with
a more circular outline the plates may be fully as elongate as in Echinocrepis and Spata-
gocystis. This elongation of the actinal plates seems mainly due to the greater or less eccen-
tricity of the actinostome, and is not always an indication of the more Spatangoid affinity
of the genera, where we find the test on the abactinal surface as in Sixitagocystis and espe-
cially in Cystechinus composed of coronal plates, showing but slight dift'erences in size in
adjoining ambulacral and interambulacral areas, which are thus made up of very nearly the
same number of plates, somewhat as we find it among some of the genera of Ananchytidse.

The anal snout has completely disappeared, the only remnant of it is the very slight
rounded actinal keel extending from the actinal edge of the anal system a short distance
towards the actinostome. The rounded arched and somewhat projecting posterior ex-
tremity of Spatagocystis, forming a sort of hood over the anal system, is barely rej^re-
sented by the slightly projecting extremity of the median interambulacral area of the test
immediately alcove the anal system. With the disappearance of the anal snout the sub-
anal fasciole has also vanished, and the miliaries, the last of this fasciole, are merely
somewhat crowded on the actinal edge of the anal system, and on the edge of the plates
of the test forming the outline of tlie anal system.

REPORT ON THE ECHINOIDEA. 145

*Echinocrepis cuneata (Pis. XXVIL, XXXV. " figs. 8-13 ; PI. XXXIX. figs. 31, 32 ;
PI. XLI. figs. 30, 31 ; PL XLIII. fig. 14 ; PL XLV. figs. 44, 45).

Echinocrepis cuneata, A. Agassiz, 1879, Proc. Am. Acad, vol. xiv. p. 206.
Seen from the anterior extremity (PL XXVIL fig. 5) the outline is that of a truncated
cone, with rounded corners and a deep re-entering angle formed by the rndth of the
actinal groove. Seen from the posterior extremity the broad rounded anal keel project-
ing over the anal system (PL XXVIL fig. 4) extends below the general level of the
actinal surface, and when seen in profile (PL XXVIL fig. 3 ; PL XXXV.* fig. 11) forms
an indistinct hood over the anal system.

The apical system of this species is compact (PL XXVIL fig. 9), placed in the trivium
and separated by the accessory interambulacral plates from the bivium, the genital plates
are indistinct, the madreporic body is very prominent ; the interambulacral plates are ren-
dered prominent l)y the presence of a single large primary tubercle on each plate replacing
the regular uniform granulation of smaller primaries covering the greater pai-t of the rest of
the test as in Plate XXVIL fig. 8. The test is covered on the abactinal side with primary
tubercles, quite uniformly but irregularly distributed over the plates of the ambulacral
and interambulacral systems (PL XXXV.* figs. 9-12). These carry small, slender, fine
spines of a moderate length. The space between the primaries is filled with minute secon-
dary spines (PL XXVIL fig. 8). Minute triangular pediceUarife are found specially
numerous in the depressed median ambulacral spaces. Near the abactinal system a
number of larger primary tubercles are placed on the upper plates of the interambulacral
areas (PL XXVIL figs. 1, 3, 5, 9 ; PI. XXXV.* figs. 9, 11) ; these carry somewhat larger
and longer spines than those on the rest of the test. The actinal side is generally flat
with a slight rounded ridge, formed Ijy the actinal keel, extending from the anal system
to the actinostome and the indistinct ridges formed in the median line of the anterior
interambulacral areas ; there these ridges form lines from which the test slopes to the
depressed median lino of the anterior lateral ambulacra. The primary tubercles of the
actinal keel are large and closely crowded, extending round the anal extremity (PL
XXVIL fig. 10; PL XXXV.* fig. 10). The other primary tubercles of the actinal
side are also larger and more distant than on the abactinal side (PL XXVIL fig. 1 ;
PL XXXV.* fig. 10); they are again somewhat smaller, and more closely packed on the
anterior part of the test towards the ambitus, on the actinal side, and in the anterior in-
terambulacral areas. The general ground tint of the test is violet-brown, the spines are
brownish-yellow, but when denuded the test is light violet.

The spines immediately in the actinal groove are longer and larger than any
others on the test and slightly club-shaped. The anal system is elliptical, placed on
the actinal side of the test on a slightly inclined plane, forming the junction of the
actinal and abactinal surfaces at the posterior extremity of the test (PL XXVIL
figs. 3, 4, 10; PL XXXV.* figs. 10, 11). The anal pouch is quite flat and

(ZOOL, CHALL. EXP. PART IX. 1881.) I 19

146 THE VOYAGE OF H.M.S. CHALLENGER.

shallow. The test of this species is comparatively stouter than in the other genera of
the family.

There were, unfortunately, only two specimens collected by the Challenger ; they are
figured natural size on Plates XXVII. and XXXV. '^

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E.; 1600 fathoms;
bottom temperature, 0*8° C. ; globigerina ooze.

* Urechinus.
Urechinus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 207.

At first sight this genus appears closely allied to Neolampas, of which it has the
general outline. The posterior region of the test forms as in that genus the
hood protecting the anal system. The difference in the proportion of the plates
composing the ambulacral and interambulacral areas as well as the structure of the
actinostome at once distinguish it from Neolampas. It has, like the Pourtalesise, large
high plates forming the ambulacral zones differing little in height from the adjoining
ambulacral plates. It has a nearly circular actinostome like that of Ci/stechimis slightly
sunken below the level of the actinal surface. The abactinal system is disconnected ;
two of the genital plates go with the trivium, the others with the bivium.

''Urechinus naresianus (PI. XXIX figs. 1-4; Pis. XXX., XXX.^ figs. 1-14; PI.
XXXIX. figs. 29, 30 ; PI. XL. figs. 56-58).

Urechinus naresianus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 207.

The largest specimens collected measured 48 mm. ; the test was of a reddish-brown
colour forming the ground- work upon which stood out in prominent contrast the delicate
slender primary spines with broad bases (PL- XXX. fig. 20), of a yellowish-white, as well
as the numerous minute secondary and miliary spines thickly crowding the whole test.
In these large specimens the primary tubercles remain comparatively large ; they are
never numerous, each primary coronal plate carrying but few ; they are more numerous on
the actinal side. In the younger stages, even when the specimens have attained 25 mm. in
length, each coronal plate was occupied by but a single primary tubercle both in the ambu-
lacral and interambulacral areas (PI. XXX. figs. 1-3), the rest of the plate being thickly
covered by miliaries and secondaries. The youngest specimens collected have akeady the
same general arrangement, and differ but little from the older specimens (PI. XXX. figs.
4-13) ; these are somewhat more elongated and more flattened; the anterior extremity
of the test when seen in profile (PL XXX. figs. 9, 13) being comparatively more gibbous.

In all the stages examined the actinal surface was more closely tuberculated
than the abactinal region, the miliary and secondary sjjines forming a close
down over the whole of that surface. Seen from above the test is elliptical, slightly
tapering at the posterior extremity (PL XXIX. fig. 1 ; PL XXX. figs. 1, 4, 7, 8, 11). Seen

REPORT ON THE ECHINOIDEA. 147

in profile, the test slopes regularly from the anterior to the posterior extremity in the
adult (PI. XXX. fig. 2), this posterior extremity is sharply arched over the anal hood
then vertically truncated, sloping anteriorly with a rounded corner joining the indistirict
actinal keel (PL XXIX. figs. 2-4). In younger specimens the anal system is more at
the extremity of the narrow end of the test (PI. XXX. figs. 5, 9, 13), and the actino-
stome is also somewhat more central (PI. XXX. figs. 3, 10) than in the older specimens
(PI. XXIX. fig. 3). In the youngest specimens, measuring 14 mm., there is already an
indistinct subanal fasciole (PI. XXX. fig. 19) ; this fasciole is never very distinct, the
miliaries of the band being always more or less disconnected as in the specimen figured
on Plate XXX. fig. 19, which measured 24 mm. in length. The anal system consists of
numerous small irregularly-shaped plates (PI. XXX. fig. 18). The indistinct actinal keel
of Urechinus is scarcely more prominent than in such genera as Rhynchopygus and
Cassidulus. Large trifid long-stemmed pedicellariae (PI. XXX. fig. 22) are found in
the actinal region near the actinostome ; the shorter round-headed pediceUarise
(PI. XXX. fig. 23) occur on the abactinal surface of the test above the ambitus.

A large number of specimens of this species were collected, showing a great degree of
variation in the tuberculation of the abactinal surface of the test (compare Pis. XXX.
and XXX.''), in the outline of the test not only when seen from above (PL XXX.
figs. 1, 7), but especially when seen in profile and from the anterior and posterior
extremities (compare PL XXX. figs. 2, 5, 6, 9, 13, with PL XXX.» figs. 3, 4, 5, 7,
12-14).

In the specimen figured on Plate XXX.'' figs. 7-9, we find that it agrees very closely
with the young of Plate XXX. figs. 1-3. In another specimen (PL XXX." figs. 10-14)
the outline in profile is quite difierent (PL XXX." fig. 12), the test is highest posteriorly,
and we find a slight tendency to the development of an anal snout. The anal system is
more elliptical (PL XXX.* fig. lOo), and the subanal fasciole is quite markedly developed,
and the primary tubercles are somewhat more numerous. This specimen also had only
three genital pores, whUe in specimens of the size of fig. 8, Plate XXX." there are usually
four. The madreporic body is quite indistinct both in figs. 8 and 11 (see fig. 8a). There
is in these two specimens (PL XXX." figs. 9, 10) quite a marked accumulation of mUiaries
on the edge of the actinal interambulacral plate, rudimentary bourrelets as it were.

I have also figured on Plate XXX.* figs. 1-6, an elongate conical specimen of
Urechinus, which I refer with some doubt to this species. At first sight it appears
totally distinct, but with the exception of the apex of the test there are no structural
difi"erences to be noticed in this specimen. The test is comparatively thitiner ; the
striking feature is the great development of the anterior lateral interambulacra near the
apical part of the test, forcing the ambulacra towards the posterior extremity (PL XXX.*
figs. 1, 3). It is difficult to make out satisfactorily the plates composing the sharp crest
which forms the apex of this specimen (PL XXX.* figs. 1, 3, 4, 5). We could imagine

148 THE VOYAGE OF H.M.S. CHALLENGEE.

this specimen to be an exaggeration of some of the younger stages (PL XXX. figs. 6, 7),
which show a very marked tendency towards a high conical test. The specimen figured
on Plate XXX.^ figs. 1-5 has, like the younger stages, only one large well-developed
primary tubercle on each coronal plate of the abactinal part of the test. This abnormal
specimen of Urechinus 7iaresianus shows how close is the afiinity between Urechinus
and Cystechinus, and that we may have in these genera fully as great a difi"erence in the
outline of the test as we find in any of the species of Ananchytes from the Chalk.

The colour of the test in alcohol varies from a dirty yellow to a dark brownish-red.

Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E. ; 1375 fathoms;
bottom temperature, 1"5° C. ; globigerina ooze.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. ; 1600
fathoms ; bottom temperature, 0'8° C. ; globigerina ooze.

Station 158. March 7, 1874. Lat. 50° 1' S., long. 123° 4' E. ; 1800 fathoms;
bottom temperature, 0"3° C. ; globigerina ooze.

Station 302. December 28, 1875. Lat. 42° 43' S., long. 82° 11' W. ; 1450
fathoms; bottom temperature, 1'5° C. ; globigerina ooze.

* Cystechinus.
Cystechinus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. i). 207.

This genus has the facies of Ananchytes, and is also closely allied to Galerites.
It has, like the latter, the test made up of plates of nearly uniform size in the different
interambulacral areas, and large plates like the Ananchytidse in the ambulacral areas,
and a slightly sunken actinostome. In this genus the actinostome is less eccentric than
is usual in Spatangoids, and in this respect one of the Galeritic features of the genus is
strongly marked. The anal system is just below the ambitus, but it has the abactinal
system of the Ananchytidse. It, however, forms a most interesting genus, and with
Pourtalesia, which was first described from the dredgings of Mr Pourtales and the allied
genera Palceotropus, Neolampas, and the like, shows the affinities of the Spatangoids
with the Echinolampadse.

It has, like aU Pom-talesiae, simple ambulacral pores. It is remarkable how the
structure of so many of the Spatangoid forms is satisfactorily explained by the different
genera of Pourtalesise collected by the Challenger, and how greatly the knowledge of the
members of this family has helped us to understand the true relationship, not only of
many aberrant groups of Spatangoids, Ijut also their relationship to the Clypeastroids
and Echinolampadse.

In addition to the proportions of the coronal plates in the ambulacral and inter-
ambulacral areas, the rudimentary auricles, the raised edge of the actinal opening
described in the following species are points specially interesting.

REPORT ON THE ECHINOIDEA. 149

'"Cystechinus clypeatus (PL XXXV.'' figs. 10, 11; PI. XLIL figs. 15, 16; PI. XLV.
figs. 29-31).

Cysteehinvs clypeatus, A. Agassiz, 1879, Proc. Am Acad., vol. xiv. p. 208.

Numerous fragments of a large species of Cystechinus were collected, some of whicli
were fragments of tlie aliactinal surface with the anal system well preserved. This
showed a difi"erent arrangement of plates from those of either Cystechinus vesica or
Cystechinus loyviUii, both in the apical system and in those of the coronal plates of the
abactinal region. The terminal coronal plates are larger and form rows, the inter-
ambulacra and ambulacra consisted evidently of fewer plates than in the other species of
the genus. The abactinal system resembles closely that of Cystechinus imjvillii; the
genital plates are, however, proportionally larger, the left anterior and the right iDosterior
far exceeding the others in size, and extending entirely across the abactinal area, the
whole central jjart of which is formed by the junction of the genital plates.

The madreporic body is more concentrated, than in any other species of this genus,
forming a sharp, well-defined triangular button on the right anterior genital plate. There
are four genitals all equally developed, and, in the fragments preserved, all greatly
expanded, forming huge clusters round the apical system. A piece of the aetinal surface
near the actinostome shows that in this species the aetinal surface is more closely
covered with primary tubercles than the other parts of the test. The spines are
whitish, long, slender, cylindrical, somewhat curved, the shaft slightly swollen towards the
anterior extremity beyond the middle. The miliaries are quite numerous, carrying short,
straight, sharp cylindrical spines. Near the actinostome the primary spines are short and
club-shaped, and the whole space between the primaries is thickly covered with secondary
spines and short-stemmed pedicellarise, which are large-headed, pyramidal, and rounded.

The aetinal membrane and the immediately adjoining parts of the test are thickly
covered with short miliary club-shaped spines. The large elliptical anal system is placed
with its longest diameter vertically, and is protected by numerous irregularly-shaped
plates (PL XXXV.'' fig. 11) carrying miliaries; the anal opening is small and placed
centrally. The edge of the test adjoining the anal system is thickly covered by miliaries
forming a broad band, with an indistinct outer edge (almost a fasciole) surrounding it;
this band of miliaries gradually passes into the miliary tuberculation of the adjoining
part of the test.

The test of this species is quite stout, judging from the thickness of the fragments
preserved, and measuring similar parts of Cystechinus ivyvillii; this species must have
attained at least 200 mm. in diameter. In the specimens from the greatest depths at
which this species has been found, the test is much thinner than in the fragments which
are found near the 1000 fathom line.

As a general rule among the Pourtalesise, the test of the diff"erent species ha\'ing an
extended bathymetrical range varies very materially in thickness, according to the depth

150 THE VOYAGE OF H.M.S. CHALLENGER.

at which the specimens were dredged. Specimens of the same species from shallower
regions, having pretty generally a comparatively stouter test. I may refer to the
evidence furnished from the different species of Pourtalesia, Cystechinus, and Urechinus.

Station 133. October 11, 1873. Lat. 35° 41' S., long. 20° 55' W.; 1900 fathoms;
bottom temperature, 1 -3° C. ; globigerina ooze.

Station 205. November 13, 1874. Lat. 16° 42' N., long. 119° 22' E.; 1050 fathoms;
bottom temperature, 2*4° C. ; grey ooze.

Station 334. March 14, 1876. Lat. 35° 45' S., long. 18°31'W.; 1915 fathoms;
bottom temperature, 1'5° C; globigerina ooze.

^Cystechinus vesica (Pis. XXXV., XXXV.« figs. 5-8; PI. XXXIX. fig. 27; PL XLL
figs. 36, 37; PI. XLIIL figs. 9-12; PI. XLV. figs. 32-35).

Cystechinus vesica, A. Agassiz, 1879, Proc. Ain. Acad., vol. xiv. p. 209.

This species is distinguished by the large size of the ambulacral plates of the abactinal
side, the uniform structure of the ambulacra on the actinal side, and the regular arrange-
ment of the coronal plates on the abactinal side of the test.

The anal system is made up of numerous irregularly-shaped plates (PI. XXXV. figs.
9, 10). The ampulla3 (PL XXXV. fig. 13) of the tufted actinal tentacles (PL XXXV.
fig. 20) round the actinostome are elongate. The majority of the primary spines are
solid, straight, longitudinally striated (PL XXXV. fig. 14), with a broad base or else
smooth and cylindiical. A few large club-shaped primary spines (PL XXXV. fig. 15)
coarsely striated at the extremity and slightly curved were also left. The smaller miliary
spines are also club-shaped, slightly curved, and with serrated edges at the extremity.
The apical system is disconnected, supernumerary interambulacral plates separating the
bivium from the trivium (PL XXXV.^ fig. 5) ; there are three genitals (PL XXXV. figs.
6, 7), forming small grape-like clusters attached closely to the apical system ; the mad-
reporic body is large. Pedicellarise of three kinds, one of which is similar to the
Clypeastroid pedicellarise of Pourtalesia figured in the Revision of the Echini, the second
kind are large, trifid, triangular and short-stemmed (PL XXXV. fig. 16), the third
kind are short-stemmed and club-shaped (PL XXXV. figs. 17, 18).

The actinal system is covered by a small number of large triangular plates, extending
from the actinal edge of the test to the actinostome (PL XXXV. fig. 12); on the abactinal
surface of the test the tubercles are not as closely placed as upon the actinal side ; we find
only a small number of primary sj)ines irregularly scattered over the test (PL XXXV. figs.
1,2); the miiiaries and secondaries are few in number and irregularly scattered over the
coronal plates. Actinostome not labiate, circular (PL XXXV. figs. 8, 11, 12), wdth a
slightly, raised edge internally corresponding to the auricles in the regular Echinids and
Clypeastroids. In this species the relationship of this genus with the Desmosticha and
Clypeastroids is quite striking. The large ambulacral plates, the barely disconnected

REPORT ON THE ECHINOIDEA. 151

ambulacral system at the abactinal pole, the flat aetinostome with its internal rudiments of
supports for teeth still existing, are all features which we do not associate with the
group of Spatangoids. I have already called attention to the general similarity of this
genus with Galerites; in the latter we still find teeth, smaller ambulacral plates, the same
aetinostome, however, only more Clj'peastroid ; and the arrangement of the tubercles
(primary, secondary, and miliary) is very similar in Galerites to that of the tubercles of
the present group.

The outline of the test of this species when seen from the apical pole on the actinal
surface is elliptical, the anterior and posterior extremities equally rounded (PL XXXV.
figs. 1, 3). The aetinostome is placed somewhat in advance of the centre, the apical
system and apex are coincident, slightly posterior. The actinal surface is flat, slightly
sunken from near the ambitus; the ambitus forms a sharp curve between the actinal
surface and the sides of the test (PI. XXXV. fig. 2) ; owing to the extreme tenuity of
the test, it is difficult to see its outline when seen in profile, the mere weight of
the test forming large folds extending from the apex to the ambitus (PI. XXXV. figs.
1, 2, 4). The outline when fully expanded, probably resembled that of Cystechinus
ivyvillii, only at the ambitus the test is less gibbous, the posterior extremity more rounded
and sloping more vertically, and the anterior extremity sloping quite uniformly with but
a slight re-entering angle from the rounded apex to the ambitus.

It is difiicult in the ill-shaped test, looking like an old felt hat, figured on Plate
XXXV. fig. 4, to recognise the outline of a graceful test such as this species undoubtedly
had, judging from that of the allied Cystechinus ivyvillii.

The anal system in this species is placed well above the actinal surface flush with the
test (PI. XXXV. fig. 2), and there is no trace of a hood or rudimentary abactinal beak as
in Cystechinus wyvillii.

This is the only Spatangoid thus far known, which can evidently expand or contract
its test. This was known in the Diadematidse (Astro^yyga) among the regular Echiuids,
previous to the discovery of the Echinothuridse among the recent forms; in these the test
is, as I have said, capable of very great expansion and contraction and extensive change
of shape. The lapping of the coronal plates of some Sjaatangoids, to which Ludwig' has
called attention, is undoulstedly an ajjparatus adapted within narrower limits for the same
purpose.

Station 153. February 14, 1874. Lat. 65° 42' S., long. 79' 49' E.; 1675 fathoms;
mud.

Station 298. November 17, 1875. Lat. 34° 7' S., long. 73' 56' W.; 2225 fathoms;
bottom temperature, 1'3° C. ; grey mud.

Station 299. December 14, 1875. Lat. 33' 31' S., long. 74° 43' W.; 2160 fathoms;
bottom temperature, 1'1° C. ; grey mud.

' H. LucUvig, Morphologie der Echmodenuen, 1877-79, vol. iii. \y[}. 131-140.

152 THE VOYAGE OF H.M.S. CHALLENGEE.

*Cystechmus ivyvilUi (PI. XXIX. figs. 5-8 ; Pis. XXIX.^ XXIX.'^ ; PI. XXXIX.
fig. 28 ; PI. XL. figs. 59, 60 ; PL XLI. figs. 23-27 ; PI. XLTI. figs. 13, 14 ; PI. XLV.
figs. 25-28).

Cystechiims Wyvillii, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 208.

In a large specimen figured on Plate XXIX.* the outline of the test seen from above
is elliptical, broadly rounded anteriorly, and having the posterior extremity somewhat
more pointed than the anterior (PL XXIX.** fig. 1). Seen from the actinal side the
actinostome is transversely elliptical, eccentric, placed anteriorly ; the actinal surface is
quite flat. An indistinct, low, broad, actinal keel is formed by a slight swelling of the
posterior interambulacral space between the actinostome and the anal system. The
anal system is placed near the ambitus in a slightly bevelled plane, passing to the broad,
indistinct, rounded, abactinal anal hood (PL XXIX." fig. 3). The apical system is
slightly eccentric posteriorly, so that when seen in profile the anterior extremity slopes
out more gradually from the rounded apex, which is coincident with the apical system,
than the more suddenly sloping posterior extremity.

The abactinal part of test, sloping uniformly for a short distance from the apex
(PL XXIX.* figs. 3, 4), forms a slight re-entering curve before it passes into the gibbous
ambitus, which, when seen in profile, is specially prominent in the anterior extremity of
the test owing to the eccentric position of the apex. Seen facing the odd posterior
interambulacrum the test has an uniformly arched and re-entering curve (PL XXIX."
fig. 4). This species has a comparatively stout test, and, to judge from the fragments of
some incomplete specimens from Station 296, it must have attained a diameter of at
least 130 mm., and a proportional height. The coronal plates are of very uniform size
(PL XXIX.* figs. 1-4), gradually becoming smaller towards the apex on the abactinal
surface, and towards the actinostome on the actinal surface, there is but little difference
in the size of the plates of the ambulacral system, and those of the interambulacral areas,
as in this genus the former are comparatively large. The odd posterior interambulacral
area is somewhat narrower than the other ; the lateral interambulacral areas are
slio-htly the broadest. Seen from the actinal side, the plates towards the ambitus
(PL XXIX.* fig. 2) become very much elongated, but become again quite hexagonal on
the actinal floor towards the actinostome. The whole test is covered with very small,
sharp, cylindrical, spines (PL XXIX. figs. 5-8), these and the mUiaries are sufiiciently
thick to hide completely the sutures of the plates, and the lines separating the
ambulacral and the interambulacral zones (PL XXIX. figs. 5-8). Minute pointed
pedicellarise are scattered irregularly over the whole test.

Each coronal plate (PL XXIX." figs. 1-4, 9) carries but few primary tubercles, sup-
porting thin short delicate cylindrical spines, the intertubercular space being covered with
irregularly scattered miliaries (PL XXIX." fig. 9). Each coronal plate is also ornamented
by ridges radiating from the angles of the plate (PL XXIX. * fig. 9) towards the central

REPORT ON THE ECHINOIDEA. 153

' summit, wliicli is somewhat raised ; these radiating ridges give to the abactinal part of
the test (PL XXIX.*" fig. 3) quite a variegated appearance, as they are somewhat darker
in colour than the groundwork of the plate itself. The outline of the test is extremely
variable, fully as variable as that of some of the sj)ecies of Galerites and Ananchytes.
The actinal interambulacral plate adjoining the actinost'ome is slightly turned up in the
interior of the test, and forms a thin ridge similar to the ridge connecting the auricles
in genera provided with teeth. The ovaries (PL XXIX.'' fig. -13) are thick close clusters
of short grape-like processes ; there are four genital plates, all of which carry genital organs
equally developed. The large size of the ampuUge of the ambulacral tentacles is remark-
able, they are developed into large vesicles round the actinal region (PL XXIX.*" fig. 6).

The membrane of the actinostome of the younger specimens is strengthened by a
smaller number of larger plates, forming a single row, in the centre of M-hich, on the
posterior edge of the actinal opening, are placed seven to eight smaller plates irregularly
arranged (PL XXIX." fig. 18).

This arrangement diS'ers materially from that figured on Plate XXIX.** fig. 5, of a
lai'ge specimen, in which the secondary plates of the actinal membrane have become
nearly as large as the primary row. In the actinostome of the larger specimens there
is the least possible indication of a rudimentary bourrelet in the crowding of the
three or four primary tubercles, on the actinal edge of the narrow interambulacral j^late
adjoining the actinostome (PL XXIX.* fig. 5). There is no trace of this in the younger
specimens (PL XXIX. " figs. 16, 18) ; although the primary tubercles are large, yet they
are not closely crowded together as in older specimens. The actinal opening is
generally transversely elliptical (PL XXIX.** figs. 2, 5), but this is by no means
constant, as it is in some cases nearly circular (PL XXIX.'' fig. 18). The apical
system (PL XXIX.'' fig. 14) is disconnected, two* of the genital plates belonging to the
trivium, and two to the Ijivium, separated by large intercalated interambulacral
plates, upon one of which the madi'cporic body often encroaches, and is in some cases
placed entirely upon one of the intercalated interambulacral plates. The anal system is
vertically elongated, strengthened by an outer row of large plates (PL XXIX.* fig. 20)
with a number of smaller plates immediately round the anal opening. An interior \dew
shows that the termination of the alimentary canal is sudden, forming a short intestine
(PL XXIX. ''fig. 19).

In young specimens (PL XXIX." figs. 1-12) the test is flattened, the outline seen in
profile is regularly arched, rounded anteriorly and posteriorly, and passing very gradually
to a flattened actinal surface. Seen facing the posterior extremity the test is similarly
regularly arched (PL XXIX.* fig. 11), the apical system and apex coincident and central,
the posterior extremity when seen from above, but slightly smaller than the anterior
(PL XXIX.* figs. 1, 5, 9). The anal opening, however, is already placed on the actinal
surface in the youngest of the specimens collected.

(ZOOL. CHALL. EXP. — PAKT IX. — 1881.) I 20

154

THE VOYAGE OF H.M.S. CHALLENGER.

The outline is somewhat more elliptical (PI. XXIX. " figs. 1, 5, 9), and the actinostome
more excentric than in older specimens ; the proportions of the coronal plates do not
differ materially in these younger specimens from those in the larger specimens, the
greatest disproportion being of course in the comparative size of the primary tubercles,
especially on the actinal surface. In the abactinal system in the largest of the young
specimens figured, the only difference in the arrangement of the apical plates is, that the
madreporic body has not yet encroached upon the plate separating it from the posterior
lateral genital plate (PI. XXIX." fig. 12'), and that the accessory plates separating the
genital plates from the anterior ambulacral areas are proportionally not as large as in the
largest specimen (PL XXIX.'' fig. 14), so that the ocular plates are comparatively nearer
together. In a still younger specimen, measuring only 22 mm., the apical system showed
the small intercalated plates between the anterior genital, and the termination of the
odd ambulacrum (PI. XXIX.* fig. 11'). Although the apical system is thus generally
identical, there is great variation in specimens of different sizes, in the relative size of the
genital plates, and the development of the intercalated plates.

In all these younger, more elliptical stages, the ambulacral areas are somewhat
broader in proportion to their height (PI. XXIX.'' figs. 1-12) ; than in such a large fully
developed specimen as that figured on Plate XXIX.** figs. 1-4.

On the actinal side in these young specimens, we find the plates of the ambulacral
and interambulacral areas more uniform in size ; they do not become elongated towards
the ambitus as do those of older specimens (PI. XXIX.'' figs. 3, 6, 10).

Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E.
bottom temperature, 1'5° C. ; globigerina ooze.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27 E.
bottom temperature, 0"8° C. ; globigerina ooze.

Station 158. March 7, 1874. Lat 50° 1' S., long. 123° 4' E. ;
bottom temperature, 0'3° C. ; globigerina ooze. South Australia.

Station 296. November 9, 1875. Lat. 38° 6' S., long. 88° 2' W. ;
bottom temperature, 1'2° C. ; red clay.

Station 299. December 14, 1875. Lat. 33° 31' S., long. 74° 43' W.
bottom temperature ; 1-1° C. ; grey mud.

Station 300. December 17, 1875. Lat. 33° 42' S., long. 78° 18' W.
bottom temperature, 1*5° C. ; globigerina ooze.

1375 fathoms;
1600 fathoms ;
1800 fathoms ;
1825 fathoms;
2160 fathoms;
1375 fathoms;

*Calymne.
Calymne, "Wy. Thomson, 1877 Voyage of the Challenger, Atlantic, vol. i. p. 397.

Among the Echinids described by Thomson in his Voyage of the Challenger, vol. i.
p. 397, figs. 102, 103, the present genus holds, like Cystechiniis, an intermediate position

EEPORT OX THE ECHINOIDEA. 155

between the Pourtalesise proper and such genera as Pdleopneustes and PalcBOtropus, in
which the actinostome is more or less labiate, and in which the structure of the actinal
surface resembles more closely that of the normal Spatangoids. Cahjmne has, like the
Pourtalesise, simple ambulacral pores, a disconnected apical system retaining something
also of its cylindrical shape ; two of the ovaries in the trivium, the others not developed,
the bivium well separated from it by intercalated interambulacral plates. It has a simple
actinostome, and large ambulacral plates ; the proportion between the size of the
ambulacral and interambulacral plates is similar to that in Cystechinus. It has, unlike
the Pourtalesise proper, an elliptical outline and a fasciole across the anterior edge of the
test. The median interambulacral area of the actinal side forms a narrow rounded keel
extending from the edge of the actinostome to the ambitus, but like Cystechinus a nearly
flat actinal surface with a low rounded keel extending almost from the actinostome to the
posterior edge of the test, where it runs into a small but well-defined subanal beak, the
only remnant in this genus of the anal snout of the Pourtalesiaj proper. The presence of
so well-defined a lateral fasciole in this genus is interesting, as otherwise the genus is
eminently an old type, but combining with its ancient characteristics such as the uniform
size of the coronal plates of the test on the abactinal surface, a disconnected apical system,
a simple actinostome with the remarkably simple arrangement of the plates imLmediately
surrounding it and a short elliptical outline, the more modern features of a distinct sub-
anal beak, a lateral fasciole, an anal system high upon the posterior extremity of the test
close to the abactinal surface, and an elongated actinal plastron with a well-defined
lateral fasciole.

When seen in profile this genus retains of the Pourtalesise the cylindrical shape and
the actinal surface slightly convex from the presence of a keel ; and by the position and
structure of its anal system it unites the Spatangina and the PourtalesiaB l:)y showing the
connection of Calymne to Urechinus, Cystechinus, Echinocrepis, and Pourtalesia proper,
in addition to such features as the presence of a lateral fasciole to which I have already
alluded. The general outlines of the test recall on the one side the Ananchytidse and on
the other the Dysasteridse, and even some of the Clyi^eastroids, and resemble to a very
striking degree those of the test of young specimens of Cystechinus.

""Calymne relicta (Pis. XXXIV., XXXIX. figs. 24-26; PI. XL. figs. 63-65;
PI. XLIII. fig. 24 ; PL XLIV. figs. 47, 48).

Calymne relicta, Wy. Tliomson, 1877, Voy. Chall, Atlantic, vol. i. p. 397, figs. 102, 103.

Only fragments of this species were preserved, from which, in connection with the
drawings given by Thomson in the Challenger narrative, the figures on Plate XXXIY. have
been reconstructed. I copy Thomson's description of this species (Voyage of the Challenger,
Atlantic, vol. i. p. 397). " The test is 30 mm. in length and 20 mm. in height, and
very elegant and symmetrical in form ; the outline is oval, slightly truncated posteriorly,

156 THE VOYAGE OF H.M.S. CHALLENGER.

a lono-itudiual ridge from which the sides of the shell slope off with a pleasing curve runs
along the apical surface. The oral surface is nearly flat, and a slight keel runs round its
edge, defining and limiting it very much as in Ananchytes, a fasciole follows the keel,
only leaving it and appearing for a little part of its course on the oral surface in advance
of the mouth. The mouth is oval, its long axis in the direction of the antero-posterior
axis of the test. The excretory opening is on the posterior surface above the line of the
peripheral ridge. The apical area is, if not disjunct, greatly produced, but it is difiicult
to make out the exact relations of some of the terminal plates of the ambulacral and
interambulacral series. The ambulacra of the trivium meet at an anterior pole on the
dorsal surface nearly opposite the mouth, and the two ovarial plates closing the two
anterior interambulacral series bear large ovarial openings from which, as in Aerope,
tubes of considerable length protrude ; what appears to be a separate plate, immediately
behind these bears the madi-eporic tubercle, only two ovaries are developed, and two
plates only are perforated for their ducts. The two posterior ambulacra end at a
secondary pole at a distance of about one-third of the length of the shell from the
primary pole near its posterior extremity. The structure of the ambulacra is extremely
simple, the ambulacral canal sending a simple diverticulum to a single minute pore near
the centre of each ambulacral plate. The mouth is unarmed. The surface of the test
bears somewhat sparsely scattered hair-like spines, and over the central portion of the
oral surface, and on the apical surface near the posterior pole, are groups of delicately
striated paddle-shaped spines. The general colour of the test and spines is pale green.
Either the same species, or one very nearly allied to it was obtained in considerable
numbers near Tristan da Cunha, but with a test not less than 200 mm. in length. The
shell was, however, so extremely tender and thin that even with the trawl not a single
example was got tolerably complete."

The actinostome is pentagonal (PI. XXXIV. figs. 7, 8), and is strengthened by
irregularly concentric rows of plates, the larger on the exterior edge.

Seen in profile (PI. XXXIV. fig. 3), the course of the lateral fasciole on the edge of
the slight keel, which marks the ambitus as it were, the line between the actinal and
abactinal surfaces is well shown. This lateral fasciole is somewhat broadest as it crosses
the posterior extremity of the test (PI. XXXIV. fig. 4).

The concentration of primary tubercles above the subanal beak to form an indistinct
subanal fasciole is very marked. These tubercles pass from primaries to secondaries, and
then to miliaries. It is the only case known to me of a closed area thus changed into
a plastron surrounded by what corresponds to a fasciole, but made up of primary tubercles.
The formation of an ambital fasciole in Pho7'mosonia by the concentration of secondary
tubercles seems to be an analogous case to this. Only two genital openings are developed
(PL XXXIV. fig. 2) ; the apical system is disconnected ; there are probably three interca-
lated interambulacral plates separating the Itivium from the trivium, but owing to the

REPORT ON THE ECHINOIDEA. 157

absence of genital pores, it is difficult to analyse this apical system with certainty. The
arrangement of the primary tuloercles is much Hke that of Cystechimts ; from two to five
primary tubercles, varying considerably in size, occupy the coronal plates both of the
ambulacral and interambukcral areas on the abactinal side. The spines vary greatly in
shape in different parts of the test (Plate XXXIV. figs, lla-f). The cluster of primary
tubercles of the posterior abactinal region of the test above the anal system, carry paddle-
shaped radioles (PI. XXXIV. fig. 11); on the anterior part of the test and the ridge
extending to the apical system they are more elongate, often sharp (PI. XXXIV.
figs. 11«, d). The same diversity is also found on the actinal side, where the paddle-
.shaped primary radioles are concentrated on the actinal keel and near the posterior
extremity ; the tubercles of other parts of the actinal surface, carrying very differently
shaped radioles. The miharies are uniformly scattered over the test, distant, carrying
short, slender sharp spines.

Fayal; 2650 fathoms. May 27, 1873.

PalcEOtropus.
Palceotrojms, 'Lovin, 1874, Etudes surlesEchinoiddes, p. 17 (Kongl. Svensk. Vet. Akad. Handl., vol. xi. No. 7).

The systematic position of the deep-sea genera allied to Palceotropus in having simple
ambulacra, extending from the actinostome to the apical system, suggests for criticism
the relationship of all the other Spatangoids when tested by this character alone. The
genera, which like Palceoti-ojuis, Pourtcdesia, Echinocrepis, Spatagocystis, Cystechinus,
and Urechinus have only simple pores extending from the actinostome to the apical
system in all the ambulacra differ from all the other Spatangoids living and fossil
(except it be genera hke Infulaster, of which the structure of the ambulacra is not
well known). Some of the Spatangoids proper are characterised by the difference in
structure of the anterior ambulacrum and the lateral ambulacra ; such genera, for instance,
as Brissus, Meoma, Faorina, Desoria, and Brissopsis, in which in the anterior ambula-
crum the pores are brought together and extend singly from the apex to the actinostome
(except immediately round the actinostome where the pores are separated again). In
others as in Hemiaster, PalcBostoma, Schizaster, Spatangus and Plagionotus the pores
are separated near the apical system in all the ambulacra within the peripetalous fasciole,
while they are so separated within the fasciole only in the lateral ambulacra of the former
group, and in both groups they are simple again below the peripetalous fasciole.

In genera without distinct petals, such as lAnopneustes, Paleopjneustes, Homolamjxis,
Argopatagus and Genicopatagus the arrangement of the pores in all the ambulacra
closely resembles that of such genera as Collyrites, Ananchytes, and Holaster, while in
Micraster we have the first indication of the speciaHsation found in the grouja to which
Hemiaster, Spatangus, Paheostoma, and the like belong.

Among the older genera Hemipneustes, and among the recent genera Agassizia, on

158 THE VOYAGE OF H.M.S. CHALLENGER.

the contrary, may be regarded as combining the characters of the two groups ; in
Agassizia the posterior lateral ambulacra having the usual petaloid structure, while the
anterior pair of ambulacra are only petaloid in the posterior half, the anterior half retain-
ing the characteristic features usually found only in the anterior ambulacra, and this
wenus having in addition the embryonic features of a globular test and ambulacra flush
with the test ; in Hemipneustes the double structure of the petals extends to all the
lateral ambulacra. In Echlnocardium, Breynia, and Lovenia we find, with the internal
fasciole, that the structure of the pores is again simple, while in all the ambulacra the
petals correspond to that of the group to which Hemiaster and the like belong.

Yet in all the young of true Spatangoids I have had occasion to examine, the ambu-
lacra consist of simple pores, extending from the apical system to the actinostome, the
change which characterises the groups thus spoken of taking place very gradually with
advancing age. The pairs of pores such as we find in the Cassidulidse can be traced
directly to the affinity of the CassidulidEe to such groups as Holectypus (which in their
turn retain features of the Desmosticha), and while the ambulacra assume a more or less
petaloid shape, yet the pores never come together into a single foramen. The earliest
known Spatangoids {CoUyritesf) retain this feature, and it is still found at the present
day existing to a certain extent in Homolainj^as, Argopatagus, and Genicopatagns, which
difi"er, however, from these earlier types in having the well-developed labiate Spatangoid
actinostome, and seem to hold from the structure of their ambulacral system much the
same relation to the Spatangina which Hemipneustes does to Ananchytes and Agassizia
to the Brissina.

*Palceotropus loveni (PI. XXI. figs. 3-16 ; PI. XXXIX. fig. 33 ; PI. XLI.figs. 28, 29).
Palaeotropus Loveni, A. Agassiz, Proc. Am. Acad., vol. xiv. ji. 204.
The anal system is placed above the median line (PI. XXI. figs. 3, 5), above the angle
made by the curve of the posterior extremity of the test extending from the apex, and
that extending from the actinal surface along the subanal shield. The anal system is
elliptical, transverse (PL XXI. fig. 8), surrounded by an outer row of large plates, the rest
of the system covered by plates irregularly arranged. The plates of the apical system
are indistinct (PL XXI. figs. 12, 13) ; the madreporic body is prominent; there are three
genital openings. The larger primary tubercles are perforate, crenulate (PL XXI. fig.
16) ; and the test is covered by a dense minute granulation between the primaries and
secondaries. Although Palceotropus has the rudimentary aml)ulacral system, simple
pores perforating the primary ambulacral plates as we find them in Pourtalesia, it
yet has a simple compact apical system ; the ambulacra are not disconnected as in that
group at the summit by the encroachment of large distinct interambulacral plates
extending from the ambulacral area across the apical region so as to separate the bivium

REPORT ON THE ECHINOIDEA. 159

from the trivium. This .species differs from the West Indian Paloeotroinis josephincB,
Lov., in being more elongated, in having its greatest breadth near the posterior extremity
(PI. XXI. figs. 3, 4). The apical system is anterior (PI. XXI. fig. 3); the apex, on the
contrary, is posterior, immediately above the anal system (PI. XXI. fig. 5). Seen from
the actinal side the outline is somewhat pentagonal with rounded angles (PI. XXI. fig.
4). The actinostome is transverse, very slightly sunken, scarcely labiate (PI. XXI. fig.
15), and strengthened by half a dozen large marginal plates (PI. XXI. fig. 8*) with a few
irregular smaller plates adjoining the opening ; the actinal plastron is large, covered by
large primary tubercles diminishing in size towards the subanal fascicle ; the field enclosed by
it is closely crowded by primary tubercles (PI. XXI. fig. 8). The anterior part of the test
on the actinal surface is covered by small primaries, extending somewhat above the ambitus
(PI. XXI. fig. 5) where the tubereulation of the rest of the abactinal surface becomes uni-
form in size (PI. XXI. fig. 3) , the tubercles of the interambulacral areas being larger.

Seen from the anterior extremity (PI. XXI. fig. 6) there is a row of large primary
tubercles in the interambulacral spaces extending from the ambitus to the apical system,
which are covered with spines ; the posterior part of the abactinal surface is comparatively
bare, carrying minute silk-like spines, gradually increasing in size towards the edge of the
ambitus, so that when seen in profile the sides of the test sloping towards the actinal
surface are quite thickly covered by long slender spines. The spines also increase in
length and size towards the anterior part of the abactinal surface, and are quite prominent
in the region adjoining the anterior ambulacral zone (PI. XXI. fig. 11). On the actinal
side the spines are closely packed except along the lines of the lateral ambulacral areas,
which are left comparatively bare.

The spines within the subanal plastron form a prominent tuft, cither when seen in pro-
file (PI. XXI. fig. 9) or from the actinal side (PL XXI. fig. 10). The test is extremely
thin, of a delicate pink colour, with brownish-pink spines.

Lovdn's individual was a young specimen measuring only about 11 mm., while the
smallest specimens collected by the Challenger measured more than 15 mm., and, with the
exception of a somewhat less elongate and more globular test posteriorly, agreed well with
larger specimens.

Station 210. January 25, 1875. Lat. 9° 26' N., long. 123° 45' E. ; 375 fathoms ;
bottom temperature, 12'2° C. ; mud.

HoLASTERIDiE.
Sub-family HoLASTERiDiE, Pictet.

It seems at present most natural to place the genera Homolampas, Genicopatagus,
Argopatagus, PalcBoi^neustes, and Linopneustes among the Holasteridse rather than with
the Spatangidce, but I am not inclined to assign to the Holasteridse the high rank which

160 THE VOYAGE OF H.M.S. CHALLENGER.

both De Loriol and Zittel have like Pictet assigned to the group. The characters of the
recent genera show a far closer affinity between the Holasteridse and the Spatangidae than
had been suspected from the study of the fossil species alone, and for similar resons I
should hardly wish to adopt the group PalcBOStoma of De Loriol characterised by the pen-
tagonal actinostome alone, a structural feature which in such genera as Paleopneustes,
Aceste, Aerope, and the like is shown to pass so insensibly into the labiate actinostome
of the Spatangoids as scarcely to justify us in adopting it as a character for the dis-
tinction of higher groups.

*Argopatagus.
Argopatagns, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 209.
This genus is closely allied to Homolampas ; it has like it a subanal fasciole
(PI. XXXII. figs. 2, 4), but no peripetalous fasciole ; the primary tubercles both on the
ambulacra and interambulacra are largest and most crowded at the ambitus; they become
less numerous towards the abactinal pole, and smaller though numerous towards the
actinostome. The odd anterior ambulacrum is not sunken, but like the others flush with
the test. The structure of the ambulacra is similar to that of Homolampas, but on the
abactinal surface the ambulacral plates are larger in comparison with the interambulacra!
ones than in that genus ; they are all more or less hexagonal. The primary tuliercles are
more numerous in the odd anterior ambulacrum on the abactinal side (PI. XXXII. fig. 1).
The structiu-e of the apical system is like that of Homolampas, it is compact
(PI. XXXII. fig. 6) ; there are four genital openings enclosing a distinct madreporic body,
the sutures of the genital plates are obliterated, the genitals are equally developed.
The five or six ambulacral suckers near the abactinal pole are more powerful with small
sucking disks, the other suckers rapidly becoming more slender towards the ambitus.
These large amlmlacral suckers (PL XXXII. fig. 6) form a rudimentary petaloid area
much as in embryo Spatangoids, but not by any actual petaloid arrangement of the pores.

''Argopatagns vitreus (PI. XXXII. figs. 1-6 ; PI. XXXVIII. fig. 25 ; PL XXXIX.
fig. 18; PL XLI. figs. 32-35).

Argopatagus vitreus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv.' p. 209.

In tliis species the test is gxeatly flattened, extremely thin, transparent, of a
yellowish colour. The large primary spines of the abactinal region are cylindrical,
curved, of a silvery lustre, with distant sharp spinules along the shaft. The test is quite
flattened (PL XXXII. fig. 3), and at first sight reminds one when seen from above some-
what of Maretia. There were only very imperfect specimens of this species collected,
the actinal plastron was missing in all, but as far as the actinal side was preserved
(PL XXXII. fig. 2), the primary tubercles of that side were smaller than on the upper
side and clustered together near the ambitus, forming elongate triangular patches in the

REPORT ON THE ECHIISrOIDEA. 161

interambulacral spaces between the broad bare ambulacral areas. The spines of the
actinal surface are more slender, club-shaped and hollow, while in the spines of the abac-
tinal region the shaft, although hollow, was quite thick.

The secondary spines resemble the primary ones of their corresponding surfaces ; the
miliary spines are short and straight ; there are few small globular pedicellarise on short-
stems scattered round the actinostome and near the ambitus on the actinal side. Seen
from above the outHne is elliptical (PI. XXXII. fig. 1), truncated anteriorly, the apex
and apical system coincident, the apical system being slightly posterior. The test
arches very regularly from the apex towards both the anterior and posterior extremities
(PL XXXII. tig. 3) ; the actinal surface is quite flattened, the actinostome elongated,
(PI. XXXII. fig. 5), placed near the anterior extremity (PI. XXXII. fig. 2).

The test is so thin that the radiating and circular canals can be seen through it round
the actinostome (PL XXXII. fig. 5). The anal system is placed above the actinal surface
in the ambitus, the subanal fasciole extending on to the actinal surface (PL XXXII. fig.
2). The subanal fasciole forms a horizontal line with two re-entering loops (PL XXXII.
fig. 4) below the circular anal system. This is covered with miliaries and short-
stemmed club-shaped pedicellarise. The actinostome is surrounded by a fringe of large
tufted tentacles (PL XXXII. fig. 5).

Station 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' E.; 800 fathoms;
bottom temperature, 3 "9° C. ; mud.

*Genicopatagus.

Genicopatagus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 210.

This genus has striking afiinities with Holaster, Cardiaster, and Toxaster ; the ambu-
lacra, as in Toxaster are all slightly sunken, but the structure of the ambulacra is like
that of Cardiaster, while in outline it recalls Holaster. In the structure of the ambu-
lacral system of the actinostome Genicopatagus is closely related to Paleopneustes ; it
difi'ers from it in having the odd ambulacrum rudimentarily petaloid (PL XXXI. fig. 16)
like the lateral ambulacra, also in having the uniformly-sized plates composing the ambu-
lacra above the ambitus continued to the actinostome. A similar uniformity of structure
in the plates composing the interambulacral areas of the actinal and abactinal region
also distinguishes this genus from Paleopneustes (PL XXXV. ** figs. 1, 2). The position
of the anal system is similar to that of Paleopneustes ; but while having the actinostome
of that genus and its general facies, it has not its strongly -marked Spatangoid actinal
surface, having no actinal plastron, and an abactinal system, which while not discon-
nected is yet made up of large genital plates in striking contrast to the compact apical
system of Paleopneustes.

The madreporic body covers the greater part of the right anterior genital ^ilate. In
this species the largest specimen examined showed only a single genital opening

(ZOOL. CHALL. EXP. — PART IX. — 1881) I 21

162 THE VOYAGE OF H.M.S. CHALLENGER.

(PI. XXXV.* fig. 2). The most striking feature perhaps of this genus is the small
number of coronal plates composing the test, particularly in the interambulacral areas.
This genus holds to the Spatangoids in that respect, much the same relation which
Cidaris holds to the normal Echiuids. The number of plates of the amliulaeral area is
comparatively small also, but not more so than we have found to be the case in Cyst-
echinus, compared with the number of interambulacral plates.

In fact, in the latter there is less disproportion in the number of the plates of the two
areas, although the number of plates is larger, the ambulacral plates are proportionally
larger. The ambulacra are all identical in structure, the odd ambulacrum not differing
from the lateral ambulacra in structure, but in having a less number of small plates with
double pores, the double pores giving to the ambulacra above the ambitus the least
possible petaloid appearance much as in Argojyatagus. The apical system is more like
that of Cardiaster, not being so elongated as in Holaster ; there are four large adjacent in-
terambulacral plates occupying the whole of the apical system. It has, like Cardiaster and
Holaster, a very prominently labiate actinostome ; the position of the anal system is like
that of Toxaster, while the flat actinal surface and the globular outline remind one of
Cardiaster ; the actinostome is more central than in that genus. Like the typical
Paleopneustes this species possesses no fascioles. This might perhaps be called an
eminently Galeritid Spatangoid.

*Genicoixaagus affinis (PI. XXXI. figs. 12-22 ; PL XXXV.'' figs. 1-4 ; PI. XXXIX.
fig. 20 ; PI. XLI. figs. 38, 39 ; PL XLIII. fig. 18 ; PL XLV. figs. 20-24).
Genicopatagus afinis, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 210.

In this species the primary tubercles on the abactinal side of the test are irregularly
placed on the interambulacral plates, occupying more the central portion of the plates
(PL XXXV." figs. 2, 4), the secondary tubercles scattered between them are somewhat
more numerous than the primaries. On the ambulacral plates there are from one to three
or four minute primary tubercles (PL XXXV.'' figs. 1,2, 4) with a corresponding number
of miliaries according to the size of the plates. The spines are straight, cylindrical,
rather short, larger on the actinal side (PL XXXI. figs. 12, 13), where the primary
tubercles are larger and are arranged in somewhat regular transverse rows on the
interambulacral plates (PL XXXV.'' fig. 2),^ The am1)ulacral j)lates of the actinal
surface are bare, carrying only miliary or few secondary tubercles ; the posterior
lateral ambulacra form wider bare areas than the others which are somewhat narrower
(PL XXXV.'^ fig. 1).

The colouring of this species is very various, some of the specimens were violet,
while others from the same locality were of a dirty yellowish-green. One of the yellowish-

1 Ooster has figured the spines of alliiid fossil genera of Holasteridte, which show a great similarity to those of
Genicopatagus.

REPORT ON THE ECHINOIDEA. 163

green specimens had a higher test than the violet specimens, which were all much flatter ;
otherwise no specific differences were noticed. The plates of the anal system all carry a
small secondary tul:)ercle, and the anal opening extends into a short conical i^rojection
(PI. XXX v." fig. 3). The actinostome is elongated, transverse, with a well-marked raised
posterior labial edge ; the actinal membrane is strengthened l^y a number of small plates
arranged in irregular concentric rows ; the structure of the actinal plastron is well shown
in Plate XXXI. fig. 1. The shape of the test varies considerably in the few specimens
collected ; the youngest specimens (PI. XXXI. figs. 20-22) show when seen from above
an angular outline, with a comparatively conical outline when seen in profile, and rather
distant spines. In a somewhat older specimen the outline seen from above is nearly
circular (PI. XXXI. figs. 16, 17), the apex with the apical system is posterior (PI. XXXI.
fig. 16). When seen in profile it is high (PL XXXI. fig. 19), the test sloping gradually
towards the anterior extremity and more suddenly towards the posterior extremity; the anal
system is placed high above the ambitus (PI. XXXI. fig. 18). These young specimens of
Genicopatagus would readily pass for the young of a Paleopneustes (allied to the Florida
species) were it not for the different structure of the apical system, from their general
outline and from the total absence of any fasciole. The more ordinary outline of the test
when seen in profile is represented in Plate XXXI. fig. 14, which shows a much more
flattened test and a rudimentary, rounded anal keel below the anal system (PL XXXI.
fig. 15). The anal system is also, in this older specimen, nearer the ambitus than in
the specimen of Plate XXXI. figs. 16-19 ; while in the youngest specimens it is placed
immediately above the ambitus (PL XXXI. fig. 20). The outline of these older specimens
seen from above does not differ materially from that of the younger more conical speci-
mens ; the anal extremity is somewhat more pointed (PL XXXI. figs. 12, 13).

Station 157. March 3, 1874. Lat 53' 55' S., long. 108° 35' E. ; 1950 fathoms;
diatom ooze.

Homolampas.

lAssonotus, A. Agassiz, 1869, Bull. Mus. Comp. Zool., vol i. {non Sclionh).
Homolampas, A. Agassiz, 1872, Eevis. Ech., part 1, p. 137.

I have already alluded in the Revision of the Echini to the similarity in structure of
the abactinal ambulacral region of Homolampas to that of Cardiaster and Holaster.
In the large species {Holaster fulva) discovered by the Challenger, the close afiinity
of the genera is still more evident. Homolamp)as has very rudimentary petaloid
ambulacra; it has a peripetalous fasciole which corresponds to the lateral fasciole
of Cardiaster, having, like it, nothing exactly limiting the ambulacra until they
nearly reach the ambitus, where its lateral fasciole would occupy homologically
the position of a peripetalous fasciole, and pass below the anal system, though in
reality it is a lateral fasciole as we understand it among the recent genera. The next

164 THE .VOYAGE OF H.M.S. CHALLENGER.

step is the appearance of a limited subanal fasciole or of a subanal fasciole with anal
branches ; something like this we find in .Homolamjxis. In Homolampas fragilis we
have an indistinct anal fasciole branching from the subanal fasciole, the peripetalous
fasciole evidently developing only at a late stage. This genus has on the whole more
important embryonic features than other Spatangoids of which the development is known;
Hemiaster and Schizaster, it is interesting to note, show quite a marked difference in the
appearance of the fascioles if we can judge from the two species of Hemiaster thus far
discovered. Yet while in the genus Homolamjoas the structure of the ambulacra show
such embryonic features as to connect it with some of the most typical of the Cretaceous
Echinoderms, there are other features which in their turn give it a most modern facies.
These are the highly specialised subanal fasciole, the compact abactinal system which
the genus has in common mth Pcdeopneustes, Linopneustes, Argopatagus, and other
Spatangina not possessing petaloid ambulacra ; the development of its primary tubercles
as in Lovenia, and the well-defined actinal plastron and specialisation of the tubercles of
the actinal surface. The resemblance of the miliary tuberculation of Homolampas fidva to
that of Spatangus loncophorus, Meneg., figured by Dames (1877, Palaeontog., vol. xxv.,
pi. ix. fig. 6), is very remarkable, and were it not for the singularly well-developed
petaloid ambulacra of the Tertiary species, we could most readily assign it to the genus
Homolampas from the outline of its test, as the delicate peripetalous fasciole would very
easily escape notice unless the specimens were in an extraordinary state of preservation.
Unfortunately, nothing is knowTi of the structure of the actinal sm-face of that species.

Argopatagus and Homolampas agree in having a flattened test, a labiate actinostome,
and a well-developed subanal fasciole, and in having the typical Spatangoid embryonic
ambulacra such as are characteristic of the Cretaceous genera Holaster and Cardiaster and
other Ananchytidse ; while in Genicopatagiis, with which both Argoj)atagus and Homo-
lampas are closely allied, the outline of the test resembles to a remarkable degree that of
Holaster and its allies.

* Homolampas Julva (Pis. XXIV., XXXVIII. fig. 26).

Homolampas fulva, A. Agassiz, 1S79, Proc. Am. Acad., vol. xiv. p. 209.

Although this is a gigantic species compared to the small Homolampas fragilis which
I described from among the Echinids dredged by Mr Pourtales in the Straits of Florida, I
do not hesitate to refer it to the genus Homolamptas in spite of the very rudimentary
petaloid structure of the abactinal part of the lateral ambulacra. This species has all the
other features characteristic of the genus, such as the slightly sunken anterior ambula-
crum, the deeply indented test at the edge of the anterior extremity, the very elongated
lateral posterior ambulacra, the presence of a subanal fasciole, the position of the anal
system, and of the actinostome, the structure of the actinal surface, and especially the pre-
sence of huge primary tubercles like those oi Lovenia in the abactinal part of the interambu-

REPORT ON THE ECHINOIDEA. 165

lacral areas. As many of the characters which distinguish. Homolampas fragills from
Homolampas fulva are mainly due to age, such as the absence of rudimentaiy petals in
Homolamixts fragilis, the small number of very large primary tubercles, the difference in
the outline of the subanal fasciole, and the ^jresence of a thread-like peripetalous fasciole,
I will make no immediate comparison between them. Homolamjyus /idva is a large species
measuring no less than 95 mm. in length. Seen from above the test is elongated, heart-
shaped, deeply indented (PI. XXIV. fig. 2) at the odd anterior ambulacrum, with a sharp
cut immediately above the anal system (PI. XXIV. fig. 2) in the median interambulacral
space. Seen in profile the test is depressed, rises abruptly at the rounded anterior
extremity (from the flattened actinal surface) to the rounded apex, which is placed near
the anterior extremity, about one-quarter of the distance from the anterior edge of the
test to the posterior edge, thence it slopes very gradually towards the posterior extremity,
to the abactinal edge of the anal system, which is placed in the anteriorly truncated
posterior extremity. The ambulacral areas widen very rapidly from the apical system
towards the ambitus, where they attain their greatest width (PI. XXIV. figs. 1, 2, 8).
On the abactinal surface the plates of the ambulacral, and of the lower part of the interam-
bulacral areas, are covered by minute secondary tubercles and miliaries; the abactinal
part of the interambulacra carry, however, a few large primary tubercles entirely out of
proportion to the tuberculation of the rest of the abactinal surface. In the lateral
anterior ambulacra the anterior row of plates is covered by large secondaries, and the
posterior row by small primaries, from the apical system to the ambitus, the same tuber-
culation extending on the actinal surface of these zones to the actinostome. On this
actinal surface large primary tubercles commencing at the abactinal part of the ambitus,
are arranged in a close pavement of uniform size over the whole anterior lateral part of
the test, and over the actinal plastron (PI. XXIV. fig. 3). The lateral posterior ambu-
lacra with the odd ambulacrum above, are covered with the minute tuberculation so
characteristic of the sides of the test above the ambitus. The primary tubercles of the
actinal region are surrounded by a large sunken area (PI. XXIV. fig. 9), the intertuber-
cular spaces are filled with secondaries. Seen from the interior of the test, the larger
tubercular depressions form a pavement of rings more or less perfect (PI. XXIV. fig. 10),
much like the pavement of the purses in the interior of Lovenia. The same purses, some-
what less developed, are found in the interior of the test below the corresponding primary
tubercles of the lateral anterior and posterior ambulacra (PI. XXIV. fig. 8), the sunken
areas round these primaries are not so marked as on the actinal surface. The secondary
tubercles carry short curved spines, forming a close covering over the whole abactinal
surface, from which stand out the gigantic curved spines of the large primary tubercles
(PI XXIV. fig. 2).

On the actinal side the spines of the primary tubercles are somewhat shorter than
those of the larger curved spines of the abactinal surface ; they are spathiform and closely

166 THE VOYAGE OF H.M.S. CHALLENGER.

packed together (PI. XXIV. fig. 3). The lateral posterior ambulacra and the odd anabulacrum
are covered by minute miliary spines similar to the secondary spines of the abactinal surface.

The subanal fasciole is broad, ^Dentagonal, pointed towards the actinal surface ; the anal
system is vertically elongate covered by a close granulation, the anal opening is near the
abactinal extremity (PL XXIV. fig. G), the intestine leading to this is short and slender
(PL XXIV. fig. 5).

There is a very narrow thread-like peripetalous fasciole extending across the tip of the
lateral petals in the odd posterior interambulacrum and the lateral posterior interambu-
lacra, which becomes lost in the lateral anterior ambulacra (PL XXIV. figs. 1, 2).

The abactinal system is compact ; the sutures between the genital plates are entirely
obliterated; there are four genital openings (PL XXIV. fig. 12) leading to four equally
developed genital glands, forming short grape-like clusters near the abactinal system (PL
XXIV. fig. 6). The madreporic body extends between the genital openings, and beyond
them in the posterior interambulacrum (PL XXIV. fig. 12). Seen from the interior of the
test, the calcareous canal forms a couple of loops for the passage of the genital ducts
(PL XXIV. fig. 7). The actinal ojoeningis pentagonal, pointed anteriorly, slightly labiate
posteriorly ; the actinal membrane is strengthened by small plates regularly arranged
(PL XXIV. fig. 11) ; the actinal tufted tentacles are comparatively small.

The abactinal system of Homolampas closely resembles that of Paleopneustes ; it also
agrees with it in having the actinal surface eminently Spatangoid, while the abactinal
surface from the presence of rudimentary petals and simple ambulacral pores with com-
paratively large ambulacral plates, recalls the Pourtalesia group proper. The presence of
a well-defined subanal fasciole and of a lateral fasciole, as well as the presence of specially
developed primary tubercles, also places this genus closer to the normal Spatangoids.
The young of this genus, as in Homolampas fragilis, shows better than in such large
species as Homolampas fulva the aflinities of the genus to Pal(BOtropus ; from this genus
it mainly difiiers in the greater specialisation of the ambiUacra, and the presence of a peri-
petalous fasciole and a more labiate actinostome.

In alcohol the test is of a light straw colour.

Station 271. September 6, 1875. Lat. 0° 33' S., long. 151° 34' W. ; 2425 fathoms ;
bottom temperature, 1'0° C. ; globigerina ooze.

Ho molampas fragilis.

Lissonotiis fragilis, A. Agassiz, 1869, Bull. Mus. Comp. Zool., vol. i.
Homolampas fragilis, A. Agassiz, 1872, Eevis. Ecli., part 1, p. 137.

Only a fragment of this species was collected by the Challenger, off the coast of
Northern Brazil.

Station 122. September 10, 1873. Lat. 9° 5' S. to 9° 10' S., long. 34° 49' W. to
34° 53' W. ; 350, 120, 32, and 400 fathoms; mud.

EEPOET ON THE ECHIKOIDEA. 107

^'Linopneustes {Paleopneustes).
Paleopmustes, A. Agassiz, 1873, BuU. Mus. Comp. Zool., vol. iii. No. 8, p. 188.

Since the preliminary examination of the specimens associated as Paleopneustes
murrayi, A. Agassiz/ I have referred to the same species a couple of smaller specimens
which throw considerable light on the specific characters of this species, and show that
both the peripetalous fasciole and the subanal exist in the smallest specimen examined
(PI. XXXV.^ fig. 9), so that it seems best for the present at least to place this species
in a sub-genus of Paleopnieustes {Linopneustes) difi"ering from Paleopneustes in having
both a peripetalous and a subanal fasciole, until we know something more of the changes
due to growth in Paleojyneustes proper. I am the more inclined to do this as the
typical Paleopneustes, forming as it does a link between the Ananch}i;id8e and Spa-
tangidse, appears fossU in the Tertiaries, Dames ^ having described a species of
Paleopneustes, which differs from the recent West Indian species in being more elongated
and having a flattened test and more petaloid ambulacra, resembling, in fact, more in its
outline the smaller specimens of Linoi^neustes murrayi, in which the test is comparatively
flatter than in the older stages, agreeing also with those younger stages in having fewer
and proportionally larger tubercles on the abactinal side of the test. The sub-genera
Linopneustes and Paleopneustes stand related to each other much as Pericosmus and
Macrop>neustes do as far as relates to the existence of a peripetalous fasciole.

The relations between PaIeop)neustes, Linopneustes, Platyhrissus and Eupatagus are
extremely instructive ; as I stated in the description of small specimens of Linopneustes
murrayi, these resemble Eupatagus in having a peripetalous and a subanal fasciole, they
agree, however, with Paleopneustes in not having petaloid ambulacra. The flattened
tests of Platyhrissus and of Eiqoatagus connect them with the younger stages of
Linopneustes, and the facies of tuberculation of Linopneustes agrees well with that of
Platyhrissus, while Platyhrissus and the typical Paleopneustes agree in not having
fascioles, while the semipetaloid anterior lateral ambulacrum of Platyhrissus forms the
passage between such petaloid ambulacra as we find in Paleopneustes, Asterostoma, and
Oviclypeus, and the petaloid ambulacra of Eupatagus, Spatangus, Maretia, Nacop)atagu$,
and the like, the petals of which are all more or less open at the extremity and some-
times even show a slight tendency to divergence.

It seems evident from the descriptions of Cotteau and D'Orbigny that there are two
distinct t}7)es in Asterostoma, one of which may prove identical with the typical
Paleop)neustes,^ while the other type is represented l)y what Dames has called
Oviclypeus,^ which has the peculiar ambulacral furrows on the actinal surface mentioned
by Cotteau in his original description of the genus Asterostoma.

» A. Aga.ssiz, 1879, Proc. Am. Acad., vol. xiv. p. 210.

2 Dames, 1877, Palseontog., vol. xxv. pi. viii. fig. 1.

3 A. Agassiz, 1874, " Hassler" Zool., Results, lU. Cat. Mus. Comp. Zool., No. 8.
* Dames, 1877, Pala'ontog., vol. .\xv. pi. x. fig. 1.

168 THE VOYAGE OF H.M.S. CHALLENGER.

In Linopneustes the pedicellarise (PI. XLIII. figs. 6-8 ; PI. XLV. figs. 11-19) do not
greatly differ from the pedicellarige of Paleopneustes, and are remarkable for the great
size of the spaces left between the valves of the head.

* Linopneustes murrayi (Pis. XXV., XXXV.^ figs. 8, 9 ; PI. XXXVIII. figs. 24, 28,
29 ; PI. XLIII. figs. 6, 8 ; PI. XLV. figs. 11-19).

Paleopneustes Murrmji, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 210.

It was with considerable doubt that I referred this species to Paleopneustes. The
presence of a subanal fasciole and a peripetalous fasciole would at first seem to remove
it from Paleopneustes, with which it agrees in its general features, such as the structure of
the ambulacra! petals, of the actinostome, and of the actinal side of the test. The series
collected is composed mainly of large specimens varying in size from 80 mm. to 130 mm. ;
in some of them the subanal fasciole is most indistinct, consisting merely of an occasional
accumulation of miliary tubercles, and the same is the case with the peripetalous fasciole
which is in some cases interrupted by breaks, or so diffuse as to lose its distinctive
character as a fasciole. So much weight has been laid upon the presence or absence of
this fasciole especially in the fossil genera, which had been multijilied now to an extra-
ordinary degree, that a careful study with large material in all possiljle stages of growth of
some of the recent genera such as Plemiaster Shizaster, Faorina and Maretia would go
far to determine whether the presence or absence of fascioles really has the systematic value
attached to it. In the species of Hemiaster which I have had occasion to study, the
changes undergone by the fascioles during growth are remarkable and the variations in
the extent and importance of the fasciole extreme. See the descriptions of Hemiaster
cavernosus collected by the Challenger.

From the specimens oi Paleopneustes proper collected by the " Blake" very great changes
in general appearance evidently take place during growth, and it may be that the frag-
ments of a species of Spatangoid which I regarded in the report on the " Blake" Expedi-
tion (Echini, Bull. Mus. Comp. Zool., 1878, vol. v. No. 9) as intermediate between
Eupatagus and Paleopneustes, may be perhaps only a species of Paleopneustes allied to
Linopneustes murrayi, having like it a very jirominent peripetalous fasciole more marked
even than in any specimen of that species I have had occasion to examine. I have called
attention to the unsatisfactory state of our knowledge of the value of fascioles while
speaking of some species of Maretia and of Lovenia, from which it would almost appear
as if disconnected lengths of fascioles might appear anywhere on the test provided the
miliaries of that portion of the test were sufficiently crowded together.

A fragment of a large sjiecimen was obtained at Station 2 1 0 in which the peripetalous
fasciole is quite close to the ambitus, running immediately on the edge of the test, and in
which the anterior ambulacral groove is somewhat deeper than in the specimens from
Japan. Around this there are from three to four smaller lines of fascioles made by the

REPOBT ON THE ECHINOIDEA. 169

miliary tubercles arranged in lines between the primary tubercles. This structure is very
marked in young specimens, and plainly shows the manner in which the fascicles pass from
miliary tubercles into the regular fascioles.

This species diflers from the West Indian species in having a more flattened test, and
better defined petaloid ambulacra ; in having a subanal and a peripetalous fasciole ; and
in having far larger and longer primary spines ditfering greatly in size on difi'erent
parts of the test ; while in Paleopneustes cristata the spines covering the abactinal
part of the test are remarkably uniform, with the exception of the tuft of primary
spines near the apex.

Seen from above the test is elliptical ; the odd ambulacrum is slightly sunken at the
ambitus, the median odd interambulacral space also re-entering immediately above the anal
system (PI. XXV. fig. 1). Seen in profile (PL XXV. fig. 3) the apical system and apex
coincide ; the apical system is central, and from this the test arches regularly towards the
anterior and posterior extremities, sloping more rapidly towards the posterior extremity,
and being more gibbous towards the anterior extremity. The posterior extremity is
truncated from the anal system placed above the actinal surface (PI. XXV. figs. 3, 5).
The actinal surface is flat, with the exception of the slightly sunken anterior ambulacrum,
and the slight keel formed by the actinal plastron, which projects but little beyond the
general level of the actinal surface (PL XXV. figs. 2, 4). The actinostome is excentric,
placed towards the anterior extremity (PL XXV. fig. 2) about one-third of the length of the
test. It is elongated, transverse, with a prominent actinal lip (PL XXV. fig. 7) with broad
ambulacral plates, separated at the edge of the actinostome by exceedingly narrow inter-
ambulacral plates ; with the exception of the broad plate forming the lip, the actinal
membrane is strengthened by two irregularly concentric rows of numerous triangular
plates ; the actinal opening is close to the posterior edge of the actinostome.

The anal system is circular, covered by numerous plates forming four or five irregular
concentric rows round the anal opening ; the outer row of plates are elongated, the others
are irregular in shape (PL XXV. fig. 6). The extremity of the indistinct rounded actinal
keel is surrounded by a broad well-marked fasciole. The peripetalous fasciole extends
from the end of the posterior lateral petal, sloping towards the end of the anterior pair
where it becomes indistinct ; its course is also very poorly defined across the odd interam-
bulacral area. This fasciole is quite narrow and often even the part running between the
lateral ambulacra, figured on Plate XXV. fig. 3, is quite indistinct and broken. On
the actinal side (PL XXV. fig. 2) the tuberculation is limited to the edge of the test
adjoining the ambitus mainly in the interambulacral spaces ; the tubercles are c|uite
uniform in size, leaving broad, bare ambulacral avenues, slightly tuberculated at the
ambitus; round the actinostome (PL XXV. fig. 7) there are only miliary or small
secondary tubercles (PL XXV. fig. 2). On the abactinal surface the tuberculation is very
irregular ; each coronal plate carries in the interaml)ulacral area a numljcr of prunary

ZOOL. CHALL. EXP. — PART. IX. — 1881) I 22

170 THE VOYAGE OF H.M.S. CHALLENGER.

tubercles generally crowded towards the upper part of the plate, with secondary and
miliary tubercles towards the lower edge (PL XXV. fig. 3) ; the edges of the plates are,
however, left quite free from tubercles, the tubercles leaving bare lines to indicate the
sutures on each side of them below the rudimentary petals ; the tuberculation of the
ambulacral area is similar to that of the interambulacral areas, only the tubercles are
smaller.

The apical system is compact ; the four genital openings large (PL XXV. fig. 5), placed
close together, well above the ocular plates ; the sutures of the genital plates are obhterated ;
the madreporic body extends into the posterior interambulacrum in a large horse-shoe-
shaped form, and extends also anteriorly between the four genital plates.

The ocular plates are triangular, rounded at the apex, with a prominent pit in which
is placed the ocular pore. Seen from the interior, the apical sy.stem shows the great
development of the abactinal part of the calcareous canal (PL XXV. fig. 8) with the
slender ducts leading from the genital openings to the genital organs.

The ambulacral pores round the actinostome give passage to tufted ambulacral
suckers ; the ambulacra are simple pores from those to the lower extremity of the
rudimentary petals formed hj the narrow more elongate amljulacral plates perforated by
pau's of pores ; these petals flare slightly at the lower extremity, the posterior lateral pair
flaring more widely and not extending quite so far towards the ambitus. The odd
anterior ambulacrum is simple, and is not petaloid towards the abactinal system. On the
abactinal side the primary spines of the interambulacral area are curved, moderately long,
the whole test thickly covered with them and the intervening mfliaries and secondaries.
On the actinal side the spines are somewhat less stout. The spines of the ambulacral
areas are smaller on the abactinal surface, and quite minute on the actinal side and in the
petaloid region of the ambulacra.

The colour of the test when denuded is reddish-brown, the spines of a brownish-
yellow colour, with occasionally lighter-coloured spines.

In younger specimens of Paleopneustes murrayi the test is quite flattened, much as
in Maretia proper ; this is contrary to what is generally the case among Spatangoids,
where, as in Brissopsis, Spatangus, Hemiaster, Schizaster, and young specimens of many
other genera, the test is quite globular, and subsequently becomes flattened or assumes the
outline of the adult ; it is, however, what we have found to be the case in the Ananchytid-
like genera such as Cystechinus, Urechinus, Spatagocystis, and also in Genicopatagus.

In young specimens measuring about 30 and 40 mm. in length, the ambulacral petals
are quite straight, and do not flare at the extremity (PL XXXV.'' figs. 8, 9). The
peripetalous fasciole is very distinct, but very thin, a mere line having much the same
course as in older specimens such as are figured on Plate XXV. fig. 3, where it is also often
reduced to a mere thread, and perhaps eventually disappears, as is the case in the
Barbados' species {Paleopneustes cristata), in which we have no such fasciole, and in

REPORT ON THE ECHINOIDEA. 171

which the young even do not have any. In fact, the general facies of the younger
specimens is more like Eupatagus than Paleopneustes. The number of large primary
tubercles is comparatively small ; they are larger, and the abactinal surface is sparsely
covered with large curved sj^ines. giving the young specimens the general appearance of a
Maretia, with few spines (PI. XXXV.'^ figs. 9, 9^). It is only in later stages that the
disproportion between the secondary and primary spines disappears, and that the test
when covered with spines resembles the specimens figured on Plate XXV.

Station 210. January 25, 1875. Lat. 9° 26' N., long. 123° 45' E. ; 375 fathoms;
bottom temperature, 12"2° C. ; mud.

Station 232. May 12, 1875. Lat. 35° 11' N., long. 139° 28' E. ; 345 fathoms;
bottom temperature, 5*0° C. ; sandy mud.

Spat ANGINA.^

Sub-family Spatangina, Gray, 1855, Cat. Eec. Ech.

Spatcuigus.
Spatangus, Klein, 1734, Nat. Disp. Ech.

Spatangus purpureus.

Spatagm purpureus, Miill., 1776, Prod. 2850.
Spatangus purpureus, Leske, 1778, Kl. Add., p. 170.

The existence of this species at the Bermudas is interesting as forming a link between
the localities from the Eastern Atlantic, where it had been known previously, and its occur-
rence in the eastern part of the Caril^bean Sea, where it has been dredged by the " Blake."

Station 75. July 2, 1873. Lat. 38° 37' N., long. 28° 30' W. ; 50 to 90 fathoms;
sand.

Ofi" Bermudas-; 100 fathoms.

Spatangus raschi.

Spatangus Raschi, Lovi^n, 1869, Ofv. Skand. Vet. Akad. Forh.

This species with its high test and small tuberculation is far more closely allied to the
Tertiary species of Spatangus, like Spatangus delphinus, than to the common Spatangus
jmrpureus. Its geographical range is also quite extensive, extending from the northern
part of the Eastern Atlantic to the Cape of Good Hope.

Station 142. December 18, 1873. Lat. 35° 4' S., long. 18° 37' E. ; 150 fathoms;
bottom temperature, 8 '3° C. ; sand.

AgulhasBank; 100 fathoms.

1 Not Euspatangina, A. Agassiz, as in Re vis, Ech., p. 219.

172 THE VOYAGE OF H.M.S. CHALLENGER.

Mai'etia (Spatangus),

Maretia, Gray, 1855, Cat. Rec. Ech,

Maretia alta (PI. XXXVII. figs. 1-4).

Maretia alta, A. Agassiz, 1863, Proc. Ac. N. S. Phila., p. 360.

As there are many excellent figures of Maretia jilanulata, I have figured Maretia alta
for the sake of facilitating comparison between these two recent species of the genus. The
specimens of this species collected by the Challenger show that it becomes considerably
larger than was previously known, one of the Challenger specimens measuring 35 mm.
^n length.

I could find no trace in the specimens examined of the rudimentary lateral fasciole
first seen by Duncan ^ in a fossil species of the genus, Maretia anomala. It, however,
occurs in the recent species of the genus, for among the many specimens of Maretia planu-
lata I found that some of them show a very distinct interrupted lateral fasciole, but far
less well marked than in Love7iia, where I have also detected a similar but a much better
defined lateral fasciole and one apparently uniformly present, which is not the case with
the rudimentary lateral fasciole of Maretia p)lanulata.

Mai'etia carinata, Bolau,''* is evidently from its very characteristic description identical
with the species I briefly noticed in 1863 in the Proc. Phil. Acad., and subsequently
described more fully in the Revision, part 3, p. 569, 1873, as Maretia alta.

The presence of only two to three large primary spines near the ambitus on the
abactinal surface gives this species (PI. XXXVII. figs. 1, 4) a very diff'erent aspect from
that of Maretia lylanulata, in which the whole of the abactinal surface above the ambitus
in the paired interambulacral areas is covered by many large primaries carrying long
curved spines often equalling in length half the length of the test, with a coarse miliary
intertubercular granulation, whde the miliary tuberculation of Maretia alta is close and fine,
the abactinal surface of the test, carrying only very short, slender miliary spines uniformly
distributed over the coronal plates. The bare ambulacral fields of the actinal surface are
also comparatively narrow in this species, the primary tuberculation of the actinal surface
extending nearer towards the actiuostome from the amljitus than in Maretia ijlanulata.
The difi"erence in coloration is also most striking, all the alcoholic specimens of Maretia
planulata are of a light straw colour, while those of Maretia alta are of a dark pinkish-
bufi" colour.

Station 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' E. ; 800 fathoms ;
bottom temperature, 3*9° C. ; mud.

Station 192. September 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129 fathoms;
mud.

' Duncan, 1877, Quar. Journ. Geol. Soc, vol. xx.\iii. p. 52.

^ Ur Heiniich Bolau Die Spatangiden des Hamburger Museums, Hamburg, 1873.

REPORT ON THE ECHINOIDEA. 173

Maretia planulata (PI. XXXVIII. fig. 23 ; PI. XL. figs. 54, 55 ; PI. XLI. figs.

17 20).

Spafangus ovaius, Leske, 1778 Kl. Add. (?iun Lamk. nee KL)
Maretia plamdata, Gray, 1855, Cat. Rec. Ech., p. 48.

Admiralty Islands. 16 to 25 fathoms. March 7, 1875.

Port Jackson. 6 to 15 fathoms and 2 to 10 fathoms. April 18, 1874.

Levuka Reef. July, 1874.

Eupatagus {Sjxitangus).
Ewpatagus, Agass., 1847, C. R., Ann. Sc. Nat., vol. viii.

Eupatagus valenciennesii (PL XXXVII. figs. 5, 6 ; PI. XXXIX. fig. 17 ; PI. XL.
figs. 11, 12).

Eupatagus Valenciennesii, Agass., 1847, C. R., Ann. Sc. Nat., vol. viii. p. 9.

I have given on Plate XXXVII. figures of this species of Eupatagus covered with
spines. From the size of the broken primary spines of the interambulacral area in the
petaloid region of the ambulacra, some of them must have attained a considerable size.
These primary spines are curved, and may have been nearly half the longitudinal diameter
of the test in length. The spines of the actinal plastron and of the interambulacral areas
of the actinal side near the ambitus, are similar to those of the abactinal region, only
considerably smaller. The rest of the test, with the exception of the tuft of longer spines
near the anal system, is covered by short slender spines of uniform length somewhat
distant, increasing in size near the ambitus on the actinal surface. The colour of the
test in alcohol is brownish-pink, darkest within the peripetalous fasciole, the primary
spines are of a reddish -yellow tint, the smaller ones darker brown, gradually passing
towards the edge of the test into the prevailing colour of the test, which is brownish-yellow
and dirty yellowish on the actinal side ; on the abactinal surface the margin of the coronal
plates forms at first a light coloured frame round the darker central part. This eventually
l^ecomes quite light coloured, and on the actinal side the test and spines are nearly of the
same tint.

Ofi' Port Jackson ; 30 to 35 fathoms.

Station 188. September 10, 1874. Lat. 9" 59' S., long. 139° 42' E. ; 28 fathoms ;
mud.

Arafura Sea.

Echinocardium.

Echinocanlium, Gray, 1825, Ann. Phil. (pars.).

The difficulty of properly limiting the genera of Spatangoids is well shown in the
diff'erent attempts which have been made to limit Echinocardium, Breynia, Lovenia, and

174 THE VOYAGE OF H.M.S. CHALLENGEE.

Amphidetus ; we are either led to unite these genera into one genus, as has been proposed
by Gray, and recognise Breynia and Lovenia merely as sub-generic types, or we are
almost forced to establish for every species a different generic section, so gradually do all
the characters upon which these genera are usually distinguished pass into one another.

Breynia, Echinocardium., and some species of Lovenia correspond remarkal^ly well in
the structure of the posterior extremity of the test ; while Breynia and Echinocardium
agree well in the structure of the actinal surface, yet in Echinocardium we can see the
beginning of the sinking of the scrobicular area so specially developed in one of the
species of Lovenia proper, while in Breynia and Lovenia, both have a peripetalous
fasciole or a partial lateral fasciole, and Breyyiia, Lovenia, and Echinocardium all agree
in the structure of the petals and in having an anterior intrapetalous fasciole. Breynia
and some species of Echinocardium agree in having no unduly developed large primary
tubercles below the petals, and the few larger primaries are placed within that area ;
the large primaries of Lovenia on the abactinal surface showing their relationship to
Spatangus, Maretia, and the like ; while in such species of Echinocardiicm as Echino-
cardium flavescens, it would be difficult to separate it from Breynia except for very
unsatisfactory reasons (the shape of the test and the presence of a peripetalous fasciole).
The greater number of primary tubercles in the anterior part of the test of these species
is, on the contrary, a feature which allies them to Lovenia as well as the slight beak
formed over the sunken anal system, which is still more prominently developed in
Echinocardium pennatifidum. As will be seen from the analysis of Breynia and Lovenia
it is evident that these genera and Echinocardium are very closely related, and might
very properly be considered as sub-genera only of Echinocardium.

Echinocardium australe.

Eehinocardium australe, Gray, 1851, Ann. Mag. Nat. Hist., jx 131.

A good series of specimens of this species was collected ; they show that the characters
which have been used to distingiiish Echinocardium australe from its Atlantic congener,
Echinocardium cordatum, are reduced to differences in the shape of the anal system, the
position of the apical system and the difference in outline of the profile of the test, with
the slight difference in the distances of the pores of the petals. These differences are
thus far quite constant in all the specimens I have examined, but seem very slight ground
for maintaining the specific distinctness of the Pacific and the Atlantic representatives of
the genus, and I should expect that additional material will prove this species to be
identical with the European species, and to have, like a few other species of Echinids, a
most extensive geographical as well as bathymetrical range.

Kobe, Japan ; 7 to 8 fathoms.

Station 234. June 3, 1875. Lat. 32° 31' N., long. 135° 39' E.; 2675 fathoms ;
bottom temperature, 1*4° C. ; grey ooze.

REPORT ON THE ECHINOIDEA. 175

Port Jackson. 6 to 15 fathoms.

Kobi, Japan. 8 to 50 fathoms. May 18 and 19, 1875.

Echinocardium jlavescens.

Spatagus flavescens, Miill., 1776, Prod. p. 235.

Echinocardium Jlavescens, A. Agassiz, 1872, Revis. Ech., f)ai't 1, p. 110.

I am unable to distinguish the specimens of this species collected at the Caj^e of
Good Hope from the northern ones. There seems to be a number of northern species of
Spatangoids which extend to the Cape ; among them are to be mentioned also Brissopsis
Itjrifera, Spatangus raschi, and Schizaster fragilis.

Station 142. December 18, 1873. Lat. 35° 4' S., long. 18° 37' E. ; 150 fathoms;
bottom temperature, 8 '3° C. ; sand.

Lovenia {Echinocardium) .
Lovenia, Des., 1817, C. R., Ann. Sc. Nat., vol. viii.
Lovenia elongata (PI. XXXIX. fig. 13 ; PL XL. figs. 45, 46).

Spatangus elongatus, Gray, 1845, "Eyre" Voyage, vol i.
Lovenia elongata, Gray, 1851, Ann. Mag. Nat. Hist.

I may state here that Lovenia elongata has been found in the Gulf of California by
Dr W. J. Fisher (Mus. Comp. Zool. Coll.), and is thus found associated on the west
coast of Central America with Lovenia cordiformis, while in the Philippine Islands it is
associated with Lovenia subcarinata.

Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E. ; 28 fathoms;
mud.

Station 212. January 30, 1875. Lat. 6° 55' N., long. 122° 15' E. ; 10, 14, and 20
fathoms ; sand.

Simon's Bay.

Lovenia subcarinata (PI. XXXV.'' figs. 5-7).

Spatangus sahcarinutus, Gray, 1845, "Eyi'e" Voyage, vol. i.
Lovenia subcarinata, Gray, 1851, Ann. Mag. Nat. Hist.

Several of the specimens of this species collected by the Challenger are somewhat larger
than those previously known. The figures given show at a glance the characters which
distinguish this species. The profile view and the abactinal view are specially important
as showing the striking difference in the structure of the posterior extremity from that
of Lovenia elongata. The anal system is small (PI. XXXV." figs. 5, 6), and is placed
at the upper extremity of a slight depression above the subanal fasciole, placed entirely
on the sloping posterior extremity aljove the ambitus, in striking contrast to the large

176 THE VOYAGE OF H.M.S. CHALLENGER.

deep pit iu which the anal system of Lovenia elongata is placed. The actinal plastron is
quite small, and the primary tubercles with sunken serobicular areas forming the adjoining
pavement, and the outer edge of the bare actinal ambulacral areas are comparatively
smaller than in Lovenia elongata and more closely packed together (PI. XXXV.'' fig. 7).

The large primary tubercles which in Lovenia elongata extend from the ambitus to
the abactinal res-ion in the anterior interambulacrum, and in the anterior half of the
lateral posterior ambulacra, are in Lovenia suhcarinata limited to two horizontal rows of
two and three large primaries (PI. XXXV.'^ fig. 5) which alone carry stout, long curved
spines on the abactinal surface. The rest of the abactinal side of the test is covered by
thin, short, slender curved spines, while in Lovenia elongata the large curved spines
extend over the greater part of the posterior extremity of the test (see pi. xix.'' Eevis.
Ech.). The tufts of spines on the two sides of the plastron enclosed by the subanal
fasciole consist of somewhat longer spines than those of the abactinal surface, and these
tufts consist of much more slender spines than those forming the corresponding tufts of
Lovenia elongata. The primary spines of the actinal surface are also shorter and com-
paratively more slender than in Lovenia elongata.

This species is also interesting on account of its rudimentary lateral fasciole, which
extends close to the ambitus from the anterior ambulacrum to about the median line of
the posterior lateral ambulacra. This fasciole is somewhat indistinct, but consists of two
to three more or less irregular horizontal lines of small miliary tubercles, differing in no
way from the smaller miliaries covering other parts of the test (see Duncan). This seems
to show quite conclusively a far closer relationship between Breynia and Lovenia than
had been suspected. In fact, if we are to take Lovenia elongata as the t}^Dical Lovenia
and Breynia australasice as the typical Breynia, Lovenia suhcarinata has, like Lovenia
elongata, the large primaries with sunken serobicular areas of the actinal surface, and the
same arrangement of the primary tubercles of the anterior part of the abactinal part of
the test, while it has the anal system and the whole of the posterior part of the test more
like Breynia australasice, and in addition the rudimentary lateral fasciole, the remnant of
the peripetalous fasciole of Breynia, which has been considered one of the principal points
of difference between it and Lovenia.

The existence of a partial lateral fasciole, both in Lovenia elongata and iu Lovenia
cordiformis, if we may so call the somewhat irregular band of miliaries extending from
the anterior ambulacrum on the abactinal side near the edge of the ambitus towards the
posterior extremity, throws considerable light on the origin of the fascioles, and plainly
shows that they are at first (at least iu Lovenia and Maretia where lateral fascioles had
not been observed) more or less irregular bands of miliary spines, which eventually
become specialised and limited to distinct areas. The origin and formation of the sub-
anal fascioles, as well as that of the peripetalous fasciole wherever I have traced it, fully
sustains this view. This helps to explain the great variation we find in the degree and

REPORT ON THE ECHINOIDEA. 177

extent of development of the fascicles in species of the same genus and often in specimens
of the same species.

Hong Kong, outside harbour. 10 fothoms. December 22, 1874.

Breynia [Echinocardium).

Breynia, Des., 1847, Agass., C. R. Ann. Sc. Nat., vol. viii.

See Lovenia suhcarhiata, where I have given an analysis of the affinities of Breynia
and Lovenia.

Breynia australasioe (PI. XXI. figs. 1, 2 ; PI. XXXIX. fig. 14 ; PI. XL. figs.

47-50).

Spatnngzi^ australashe, Leacli, 1815, ZooL Misc., vol. ii. p. 68.
Breynia australasice. Gray, 1855, Cat. Rec. Ech.

As in Eupatagus the abactinal side of the test is covered with secondary spines of
uniform size and of a light chocolate colour, with a silvery lustre in alcohol, with a few
large curved primary spines of a lighter colour in the interambulacral abactinal region of
the test, near the peripetalous fasciole. The spines increase in size towards the ambitus,
and on the actinal side become longer ; they are curved towards the bare ambulacral
zones both in the lateral interambulacral areas, and in the actinal plastron. In alcohol
the colour of the spines of the actin^d surface is much lighter than on the abactinal side ;
the large spines being of a light yellowish tint with a silvery white lustre.

Torres Straits. August 7, 1874.

Brissina.

Sub-family Brissina, Gray, 1855, Cat. Rec. Ech.
Hemia^ter.

Eemiaster, Des., 1847, Agassiz, C. R. Ann. Sc Nat., vol. vii.

Hemiaster cavernosus (Pis. XX.% XXXIX. fig. 15; PL XLI. figs. 21, 22).

Tripylus cavernosun, Phil., 1845, Wieg. Archiv, p. 347.

Hemiaster cavernosun, A. Agassiz, 1872, Re vis. Ech., part 1, p. 132.

In a large specimen of Hemiaster cavernosus no trace of a distinct anal fasciole could
be detected ; there existed, it is true, an accumulation of smaller tubercles aU round the
anal extremity. In a small specimen, however, measuring only one-third of an inch, there
was a distinct anal fasciole joined to a very broad, well-marked lateral fasciole, while in
another specimen measuring half an inch the subanal fasciole consisted only of a short arc
without any trace of the lateral fasciole. A similar difference also undoubtedly exists in

(zOOL, CHALL. EXP. — PAKT IX. 1881) I 23

178 THE VOYAGE OF H.M.S. CHALLENGER.

many species of this family, as has been noticed by Troschel, who, however, considered the
presence or absence of any fascicle as of considerable specific and even generic importance.
It is evident from an examination of many .specimens of this species, that we may have
remnants of the lateral and anal fascicle irregularly scattered round the anal extremity
either as imperfect anal fescioles or as branches of the peripetalous fascicle or as indistinct
subanal and anal fascicles or remnants of the lateral fascicle.

In a young specimen measuring scarcely an eighth of an inch, and in younger stages
(PI. XX.* fig. 9), the anal system is placed within the peripetalous fascicle, so that the
second or normal stage, as we have it in the adult, is due to the gradual passage of the
anal system from this abactinal position to one below the peripetalous fascicle, and the
formation of a new peripetalous fascicle inside of the anal system, and thus at one time
the anal system was included within a triang-ular space formed l^y a branch of the
original peripetalous fascicle, and the new base of the same turning across the odd
interambulacrum between the anal system and the abactinal system.

These branches are sometimes persistent, and have been also noticed by Troschel,
who, however, was not aware of their origin in Faorina. This secondary subanal fascicle
usually disappears with age, and is not identical with the permanent subanal or anal
fascicle which is formed at a later stage, while the other branch if persistent would form
a fascicle above the anal system. The great variation existing in the extent and distinct-
ness of the anal fascicle is well shown in the diiferences found to occur in specimens
of various sizes from cue and the same locality in Hemiaster cavernosus. It is also
plain that the anal fascicle, as such, derived its origin from the peripetalous fascicle,
while the subanal fascicle is formed independently, and may exist where no peripetalous
fiisciole is found, as in Spatangus, Maretia, and the like ; and many older genera, such
as PalcBOtroims, Argopatagus, Pourtalesia, and Urechimis.

The following description of the manner in which the young are carried in the
marsupium formed by the deeply-sunken lateral ambulacra is taken from Thomson's
account in the Voyage of the Challenger, vol. ii. p. 231 : — "In the female, the pore-plates
of the paired ambulacra are greatly expanded and lengthened and thinned out, and
depressed so as to form four deep, thin-walled, oval cups sinking into and encroaching
upon the cavity of the test, and forming very efficient protective marsupia (PL XX." fig.
6 = fig. 44). The cvarial openings are, of course, opposite the interradial areas, but the
spines are so arranged that a kind of covered passage leads from the opening into the
marsupium, and along this passage the eggs, which are remarkably large, upwards of a
millimetre in diameter when they leave the ovary, are passed; and are arranged very
regularly in rows on the floor of the pouch, each egg being kept in its place by two or
three short spines which bend over it (PI. XX.'' fig. 2 = fig. 46). Among the very many ex-
amples of this Hemiaster which we dredged in Accessible Bay, and afterwards in Cascade
Harbour, Kerguelen, there were young in all stages in the breeding-pouches, and although

EEPOET ON THE ECHINOIDEA. 179

from the large size and the opacity of the egg and embryo it is not a very favourable
species for observation, had other conditions been favourable we had all the material for
working out the earlier stages in the development of the young very fully. The eggs, on
being first placed in the pouches, are spherical granular masses of a deep orange colour,
enclosed within a pliable vitelline membrane, which they entirely fill. They become
rapidly paler in colour by the development of the blastoderm ; they then increase in size
probably by the imbibition of water into the gastrula cavity, and a whitish spot with a
slightly raised border indicates an opening which I have no reason to doubt is the per-
manent mouth, but of this I cannot be absolutely certain.

" The surface now assumes a translucent appearance, and becomes deeply tinged with
dark purple and greenish pigment, and almost immediately, without any definite inter-
mediate steps, the outer wall is filled with calcified tissue ; it becomes covered with fine
spines and pedicellarise, a row of tentacular feet come into action round the mouth, the
vent appears at the posterior extremity of the body, and the young assumes nearly the
form of the adult. These later changes take place very quickly, but they are accompanied
by the production of so much heavy purple and dark green pigment that it is difficult to
follow them. The viscera are produced at the expense of the abundant yelk, and the
animals at once take a great start in size by the imbibition of water into the perivisceral
cavity. The young urchins jostle one another on the floor of the breeding pouch, those
below pushing the others up until the upper set are forced out between the rows of fringing
spines of the pouch, but even before leaving the marsu^^ium, on carefully opening the shell
of the young, the intestine may be seen already full of dark sand, following much the same
course which it follows in the adult. The size of the test of the young on leaving the
marsupium is about 2*5 mm. in length by 2 mm. in width."

To give as fully as possible the history of this species the accompanying description of
the changes due to growth are reprinted from a notice on the Viviparous Echinids, from
Kerguelen Island,^ describing the early stages of this species.

"The function of the deej^ly sunken petaloid ambulacra of several genera of
Spatangoids, such as Moira, Schizaster, Hemiaster and the like, has thus far remained
unknown. Philippi in 1845, while describing some South American Spatangoids, found
in the deeply sunken posterior ambulacra of Hemiaster cavernosus minute Echinids, which
he regarded as the young of the species, though they differed widely from the adults, and
seemed, from their shape and the nature of their spines, to approach nearer the regular
Echinids than the Spatangoids. Echinids of this genus being but rarely found in
collections, no opportunity occurred of verifying the observations of Philippi. A some-
what analogous observation was made by Grulie, who described more in detail the
young of Anochanus {Echinobrissus), which he found living under very similar
circumstances, in a cavity opening in the abactinal pole of the specimens. No details of

' A. Agassiz, 1876, Proc. Am. Acad., p. 231.

180 THE VOYAGE OF H.M.S. CHALLENGER.

t

the nature of this cavity having been as yet published, it is not possible to compare the
two modes of carrying the young in these two genera more closely,

" In Spatangoids, with deeply sunken ambulacra, we find, nearly in all cases, that
from the sharp edge of the ambulacral groove, long spines extend, so as nearly to close
the opening of the cavity, entirely bridging it over, and completely conceahng from view
the ambulacral pores. This arrangement has usually been considered in Spatangoids
as a sort of filter to keep foreign particles from affecting the delicate water tubes, which
in the Spatangoids perform more or less the function of gills. This is undoubtedly the
case in several genera, but in the case of Hemiaster, and perhaps in other allied genera,
the sunken ambulacral area is used for an entirely different purpose, as was correctly
observed by Phdippi — that of sheltering the young.

" That the many specimens (eight) found in the two posterior sunken ambulacral
areas are really the young of Hemiaster, is, of course, only probable, from the fact that the
genital o^^enings, which are unusually large, open directly into the upper part of their
sunken area ; so that the eggs (or more properly an imperfectly developed pluteus, like that
of Echinaster) on escaping from the genital openings would readdy find their way into
the artificial cavity formed by the spines which conceal the presence of the sunken areas.

" Unlike many Echinids, the ovaries of this genus are small, consisting of compact
grape-like clusters of eggs, in very difi'erent stages of development, a few of the eggs only
attaining a considerable size (nearly 1 mm.), and apparently ready to escape into the
sunken area as soon as the place should be left unoccupied by the preceding brood. No
two of the small Echinids were in the same stage of development ; they varied in size from
2 mm. to 3 mm., the smaller specimens having a somewhat pentagonal outline, with
rounded angles ; the larger were more nearly elliptical and cylindrical in shape. In the
smaller specimens (PL XX.* fig. 7) the spines were short, straight ; the longest, and only
a few in each interambulacral area, about one-fifth the length of the axis, while the greater
number were mere tubercles, scarcely rising above the level of the test. In the largest
specimens (PI. XX.* fig. 6) many of the spines, nearly equalling the radius of the test,
had become curved and had assumed the characteristic appearance of Spatangoid spines.
Seen from below (PL XX." fig. 10) the large angular mouth, covered by a thick
membrane, was nearly central, somewhat anterior, the edge of the mouth on the level of
the test, and a few small indistinct pores arranged in parallel lines, showing the position
of the future actinal petal ; the ambulacral areas were occupied by coarse granulation,
while the tubercles of the interambulacral spaces were large with well-developed crenu-
lation, and already perforated. The interambulacral areas were already broad, leaving
but narrow ambulacral spaces, in which the short, club-shaped ambulacral tubes could
wh difiiculty be traced ; they were largest near the apex, and near the actinostome.
Seen from above (PL XX.* fig. 9), the most marked feature of all these young Echinids
was the broad fasciole, occuppng so large a part of the abactinal surface, the position of

REPORT ON THE ECHINOIDEA. 181

the interambulacral area being clearly marked by the two large tubercles at the extremity
of these areas on the abactinal edge of the fasciole. The whole fasciole was covered by
a coarse granulation. The most striking feature in the structure of these small Echinids
is the position of the anal opening (PI. XX.'' fig. 9). This is nearly in the central part
of the abactinal surface towards the posterior edge, and entirely surrounded by the
fasciole. This fasciole, from its position, must undoubtedly be the peripetalous fasciole,
as it agrees in position with the same fasciole in Brissopsis, though in the latter genus
it does not enclose the anal opening. In the adult Hemiaster the anal opening is not
thus surrounded, an additional example of the little value we can place upon the position
of the anal opening as a systematic character. The transfer of the anal opening to the
exterior of the fasciole I was not able to trace, all the specimens being too young to show
when it took place. There is no trace in these young stages of any genital openings, or
of genital plates ; the ocular plates are somewhat more prominent than the other
ambulacral plates, one es23ecially, that of the odd ambulacrum (see PI. XX." fig. 9). On
opening one of these young Echinids (PI. XX." fig. 11) we find that, notwithstanding the
position of the anal opening, the intestine akeady makes a half circuit round the edge of
the test, and is attached to the sides by the usual mesenteries, the actinal extremity of
the alimentary canal towards the anterior end being free ; the stone canal also leads
nearly vertically from the anal opening to a terminal interambulacral plate situated
to the right of the odd ambulacrum. The anal opening is large, pentagonal, separating
completely the trivium from the bivium, and is covered liy a large plate having a small
opening opposite the left posterior ambulacrum.

" The only other young Sjjatangoid known, resemljling so closely a regular Echinus,
is a young Spatangoid figured by Mliller, while still in the pluteus stage, with straight
spines similar to these figured here in the youngest specimen. This was the first
indication we had of the great simUarity of the spines of the young stages in the regular
and irregular Echinids. The presence of an anal opening in the young Hemiaster
connected, so to speak, with the abactinal system, is a most interesting feature, as well as
the complete separation of the bivium and trivium, the origin of which among Echinids
had not been understood. The whole family of CoUyritidse, in which this is the normal
state, appear in geological times as an abnormal group, disconnected entirely, and
isolated from all the other Spatangoids, which it precedes in time, and seeming thus far
to have no connection with the Spatangoids of later geological periods. Theii" connection
as an embryonic stage is now clearly shown by the young of Hemiaster, here figured, as
well as the close relationship existing between the regular Echinids and such Spatangoids
as Collyrites, appearing as the earliest geological representatives of the Spatangoids.
The CoUyritidae are, therefore, not structurally so far removed as has been generally
supposed from the regular Echinoidea.

" The earlier development, that preceding the stage when the embryo escapes into

182 THE VOYAGE OF H.M.S. CHALLENGER.

the ambulacral area, could, of course, not be traced satisfactorily. But enough could be
seen of the shape of the embryo mass to render it highly probable that the development
was very similar to that of other viviparous Echinoderms (Star-fish and Ophiurans), in
which the young are carried about by the parents till they are well advanced Star-fishes
(Sars, Mliller, Agassiz), or hatched from the main cavity as well-developed Ophiuridse
(Quatrefiiges, Schultze, Lyman, Agassiz), and where the plutean development is passed
through in a very imj^erfect manner, owing to the rudimentary development of the arms,
which take such an extreme degree of growth in the pelagic pluteus of Echiuids and
Ophiurans, traces only of these arms being found in the younger stages of growth of
these viviparous Echinoderms.

" The specimens I have had the opportunity of examining were collected at Kerguelen
Island by Dr J. H. Kidder, the naturalist attached to the Transit of Venus expedition,
and were sent to me for examination by Professor Verrill. He has described the species
as new, under the name of Hemiaster cordatus; but I cannot distinguish it from
Hemiaster cavernosus and Hemiaster australis, which I was led to consider (from
analogy with Hemiaster phili2^pii) to be identical species. It is remarkable that, in the
young stages of both these species, all the ambulacra are but little sunken, and it is only
when they have attained a considerable size that the 23osterior ones begin to deepen.
Philippi considered that this might be a sexual feature. We have not sufficient data to
decide the question, but can only say that up to a certain size, at any rate, there is no
difference in the depth of the ambulacra of males and females. (See pi. iv. figs. 4-8,
Echini of " Hassler " Expedition, lU. Cat. Mus. Comp. Zool., No. 8). I have examined
a large numlier of a common Spatangoid from our southern coasts {Moira atrojyos), with
ambulacra still more deeply sunken than in Hemiaster, in hopes of finding the young,
but thus far without success ; from the eggs of Schizaster canaliferus from the Mediter-
ranean, in which some of the ambulacra are also deeply sunken, a pelagic jjluteus is
known to be developed ; so that in many of the genera with sunken ambulacral petals
the sunken area does not shelter the young in their earliest stages of development."

Among the large number of specimens of this species collected by the Challenger there
were a few small specimens intermediate between the younger stages which I described in
the Proceedings of the Am. Acad, from specimens collected by Dr J. H. Kidder, U.S.N.,
and those which were figured on plate iv. of the " Hassler " Echini in Mem. of Museum
Comp. Zoology. These figures I have reproduced (PL XX.* figs. 13-17), although they do
not quite fill the gap existing between the stage of Plate XX." fig. 9 and PI. XX.* fig. 18,
which were known before, still they leave but little to trace in the history of the development
of the petals, and of the gradual passage of the anal system from the abactinal surface to
the posterior edge of the test, and they also show the passage of the peripetalous fosciole
from that figured in stage 1.3 until it has assumed approximately the shape of the adult
(PI. XX.* fig. 18). The development of the males and females is identical to that point,

r.EPORT ON THE ECHINOIDEA. 183

and it is only later that the differences in the depth and width of the petals becomes
apparent, as I have shown in the figures of Hemiaster on plate iv. of the " Hassler " Echini.^
" The figures given on plate iv. figs. 4-8, are aU natural size, and show the changes the
lateral ambulacra undergo as they pass from fig. 8 to fig. 7, and from fig. 6 to fig. 4.
When the specimens reach the size of fig. 7, the change from comparatively shallow
lateral ambulacra to the deep ambulacra of fig. 6 takes place without a great increase in
the size of the test. The anterior ambulacra, eventually the most concave (fig. 4), are the
first to show marked signs of depressions, and in slightly older specimens than figs. 7 or
6 they are already deeply sunken, while the posterior lateral ambulacra are comparatively
shallow. In most of the specimens examined I have found large globular, short-stemmed
pediceUariae situated in the sunken ambulacral petals, usually the anterior pair, as
mentioned by Phdippi. Owing to the comparatively long spines of the edge of the petals,
the sunken ambulacra are completely hidden by a screen of spines. The changes of out-
line of the test are very limited after the specimens have attained the size figured on
plate iv. fig. 8. The outline of the test is somewhat more angular and gibbous, seen from
above, and perhaps less conical and somewhat more flattened at the apical system. The
number of genital pores is variable, as we find two or three quite indifierently ; the
posterior pair of genital openings is always present, if a third exists it is the right anterior
one usually, but sometimes the left. In the youngest specimen figured the outline of the
peripetalous fascicle is nearly the same as in the oldest specimen examined (fig. 4), though
its breadth becomes greater with advancing age. The odd anterior ambulacrum increases
but little in dej)th and breath with increasing size."

In the magnified views of the apical system of a male (PI. XX." fig. 21) and of a
female (PL XX." fig. 22), the difference between the size of the genital openings is very
striking, as well as the sudden sinking of the floor of the apical extremity of the paired
ambulacra in the female to form the marsupial pouches. The genital openings are
developed comparatively late, there is no trace of them until they attain the size figured
on Plate XX.'' fig. 15. In one female (PI. XX.* fig. 19) there were only two genital open-
ings, and it was the left anterior which disappeared next, leaving the two posterior genital
openings.

Professor A. E. Verrill has carefully described the differences existing between the
males and females of specimens collected at Kerguelen Island by Dr J. H. Kidder
(BuU. U. S. Nat. Museum, No. 3). These specimens he described under the name of
Bemiaster cordatus (Bull. U. S. Nat. Mus., 1876, No. 3, p. G9), as he, not having a
sufficient series of the South American species [Hemiaster cavernostis and Hemiaster
australis) for comparison, preferred to regard it for the present as distinct. The specimens
he sent me at the time for comparison 1 could not distinguish from the South American
species. The Challenger series is so extensive, and shows such a range of variation

' A. Agassiz, 1874, Zool. Results of the " Hassler " Expedition, 111. Cat. Mus. Comp. Zool., No. 8.

18-4 THE VOYAGE OF H.M.S. CHALLENGER.

both in form and in the structure of the petals according to age and sex, that I am quite
convinced it is impossible to define the Kerguelen specimens as a different species. One
of the specimens from Station 310 combines the features of the two sexes in having
nearly flush posterior ambulacral petals, while the anterior petals are almost as deeply
sunken as in well-developed females of the same size.

Dr Studer also collected Hemiaster CGvclatus, Verrill, at Kerguelen Island, and
enumerates it as a distinct species in his list of Kerguelen Echinoderms (Berlin Akad.
Monatsb., July 1876, p. 457). He also speaks of finding the young in the cavity of the
external pouches of the petals of the large females. Mr Edgar Smith has also noted this
species in the Echinodermata of Kerguelen Island (Trans. Roy. Soc, 1879, vol. clxviii.
p. 272).

From the evidence furnished by the large material collected by the Challenger, there
seems but little doubt the species which have thus far been distinguished as Hemiaster
australis, Hemiaster philippii, and Hemiaster cavernosus are aU different stages of
growth of one and the same species, but owing to the great difference in structure
between the ambulacral petals of the males and females, and the extraordinary changes
this species passes through from its youngest stage uutd it has reached its adult sexual
form, it was very natural that these several stages of growth should on scanty material
have been regarded as so many distinct species.

The coloration of specimens from different localities appears also quite distinct, and in
some cases the test and spines are of a light brownish-yellow, in striking contrast to the
dark-coloured specimens found at other localities.

Station 151. February 7, 1874. Off Heard Island. 75 fathoms; mud.

Station 310. January 10, 1876. Lat. 51° 30' S., long. 74° 3' W. ; 400 fathoms;
bottom temperature, 7 '9° C; mud.

Kerguelen Island, Betsy Cove. 15, 25 and 250 fathoms.

Kerguelen Island. 10 to 100 fathoms.

"Hemiaster gihhosus (PI. XX. figs. 5, 16, 22; PI. XXXIX. fig. 16).

Hemiaster gibbosus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 210.

This is quite a large species, measuring 30 mm. in length. The outHne seen from
above is variable, in one case (PI. XX. fig. 5) it was nearly elliptical ; in another specimen
of about the same size, the posterior extremity was much the widest (PI. XX. fig. 6).
Seen in profile the test is vertically truncated at the posterior extremity, the apex is close
to the posterior edge, thence the test slopes gradually towards the anterior, somewhat
beyond the apical system. The anterior extremity is also abruptly truncated and rounded
towards the flat actinal surface. The posterior extremity of the actinal surface forms a
rounded keel, as is seen from the anal extremity (PI. XX. fig. 8). The outline seen facing
the anterior extremity is nearly globular. The small anal system is placed high upon the

REPORT ON THE ECHINOIDEA. 185

posterior extremity of the test iu a shallow groove ; the test is covered with tubercles
of uniform size equally distributed over the plates (PI. XX. figs. 5, 8), except in the
lateral posterior interambulacra, where the plates are comparatively bare (PI. XX. fig. 7),
as well as on the actiual surface (PL XX. fig. 6), where the tubercles are somewhat larger
iu the interambulacral areas and on the actiual plastron. The peripetalous fascicle is
broad, pentagonal, with rounded corners; the anterior lateral ambulacra are longer than tlie
posterior pair, the latter being comparatively short. The petals are all sHghtly sunken,
the odd ambulacral petal is the longest, and its pores are double but not conjugate
(PI. XX. fig. 9).

In the apical system there are four large genital plates ; the right anterior carries the
madreporic body (PI. XX. fig. 11); the bivium is separated from the trivium by two large
intercalated interambulacral plates. The actinostome is placed in a slight depression
formed by the sloping in of the last actinal plates of the trivium and adjoining lateral
posterior interambulacra. The posterior interambulacral labium is prominent (PI. XX.
fig. 6) ; the actinostome is narrow, transverse, the buccal shields extending from the
anterior edge occupy the greater part of the opening. The lateral petaloid ambulacra
have broad, flat, triangular feet, with rounded tips (PI. XX. fig. 22), while the suckers of
the odd ambulacrum and the other ambulacra outside of the petals have simple feet with in-
distinct suckers. The spines are long, cylindrical at the base, and slightly club-shaped at the
extremity (PL XX. fig 12) ; from the ambitus to the actinostome they are larger, longer,
and pointed, the spines of the actinal plastron are sj^ecially prominent diverging from
the median line ; they are spathiform and quite stout. The miliaries are short club-
shaped spines (PL XX. figs. 12, 14, 15) simibar to those of the fascioles, only stouter,
showing as plainly as possible that the spines of the fascioles are only minute miliary
spines arranged in definite rows. I cannot understand why writers on Echinoderms
insist continually in bringing up the relationship of the fascioles and of the viliratile
chords of the Pluteus and Brachiolarians. To any one who has studied the embryology
of Echinoderms, and has followed the homology of the spines, this appears utterly
unmeaning. AVhat possible relation there can be l)etween a chord of vibratile cilia
such as we find fringing certain plastrons of the Pluteus and the specialisation of
calcareous spines remaining in a more or less embryonic stage, and arranged along certain
lines which only appear after the young Sea-urchin has reached a considerable degree of
development, I am unable to perceive. The intermiliary granulation (PI. XX. fig. 13)
reminds us of the intermiliary granulation of such genera as Arbacia, in which these
granules are isolated and pass by degrees into club-shaped spines recalling the miliary
spines of this species.

The suckers of the petaloid ambulacra are interesting for their close afiinity to the
suckers of the petaloid area of Echinaracliniiis, which form, as it were, the natural link
between the fringed suckers of the jietaloid ambulacra of the higher Spatangoids through

(ZOOL. CHALL EXP. PART IX. 1881) I 24

186 THE VOYAGE OF H.M.S. CHALLENGER.

such forms as those of Hemiaster gibhosus here figured and those of the ordinary Dosmo-
sticha consisting of a simple tube with a terminal sucker (see Eevis. Echini., pi. xxxi.
figs. 4-9).

Station 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' E. ; 800 fathoms ;
bottom temperature, 3 "9^ C. ; mud.

Station 232. May 12, 1875. Lat. 35' 11' N., long. 139° 28' E. ; 345 fathoms;
bottom temperature, 5"0° C. ; sandy mud.

^Hemiaster zonatus (PI. XX. figs. 1-4).

Hemiaster zonaius, Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 212.

Loven has figured in his Etudes sur les Echinoidees, pi. xi. figs. 93, 94, a young
Hemiastei- [H. expergitus) collected by the "Eugenia" near the Azores at a depth
of 600 fathoms. The Challenger also dredged near the same locality specimens of a
Hemiaster which I cannot refer to Loven's species at present, although the difterences
between them are such that they may only lie due to age.

This species difl'ers from Hemiaster gibhosus in having a deeper anal groove, a broader
and more eliptical peripetalous fasciole, and coarser spines more evenly distributed over
the whole of the abactiual surface.

The outline of this species is also more globular, and it evidently has its nearest ally
in the characteristic Cretaceous Hemiaster prunella.

Station 126. September 12, 1873. Lat. 10° 46' S., long. 36° 8' W. ; 750 fathoms;
mud.

Station 8. February 12, 1873. Ofi' Gomera, Canaries ; 620 fathoms ; sandy mud and
shells.

Rhinohrissus (Hemiaster) .
Rliinohrissus, A. Agassiz, 1872, Bull. Mus. Comp. Zool., vol. iii.

* Rhinohrissus hemiasteroides (PI. XXXV.'' figs. 12-15).

RJdnobrissus hemiasteroides, A. Agassiz, 1879, Proc. Am. Acad., voL xiv. p. 211.

We find in this species a combination of some of tlie features of Rhinohrissus with
characters of Metalia, BrissojJsis, Hemiaster, and Brissus. It has the peripetalous fasciole
of the former, and the anal fasciole of the latter genera, the deeply sunken petals of
Hemiaster combined with the flush odd anterior ambulacrum and the remarkably broad
actinal ambulacral areas round the actinostome of Rhinohrissus.

At first glance when covered with spines, this species would readily be taken for a
young specimen of Metalia sternalis, but it has, unlike this species, no anterior ambulacral
groove. The anterior ambulacrum is flush with the test which forms a slight keel in the
median anterior ambulacral area (PL XXXV. ^ figs. 12, 13). The peripetalous fasciole is

REPORT ON THE ECHINOIDEA. 187

as in Metalia moderately broad, but scarcely more indented than in BrissojJsis and
Hemiaster. It has, like Brissopsis, an anal fascicle, and a closed subanal fasciole indepen-
dent of it (PI. XXXV.*" fig. 15). The actinal plastron is very elongated, narrow, extend-
ing from the diamond-shaped subanal fasciole nearly to the actiuostome (PI. XXXY."
fig. 14). The actinostome is broadly transverse, the ambulacral areas broad, carrying large
tufted ambulacral tubes to the edge of the ambitus. The spines of the abactinal surface
do not differ in their general aspect from those of Metalia sternalis. The paired ambu-
lacral petals are sunken much as in Hemiaster (PI. XXXV.'' fig. 12), the anterior pair are
widely separated, placed at right angles to the longitudinal axis ; the posterior pair make
but a slight angle with it, are less sunken and are separated by a well-defined rounded ridge.
There are four genital pores placed close together. This species seems to be intermediate
between Brissus proper and the species which have been separated from it, as Metalia
{M. sternalis) and the like. The apex corresponds as in Metalia with the abactinal
system (PI. XXXV.'' fig. 13), and is placed nearer the anterior extremity, while it is
posterior in Rhinohrissus.

The only specimens thus far collected show that this species is smaller than Rhinohrissus
pyramidalis ; the spines of the abactinal surface are short, of uniform size ; on the actinal
side in the lateral posterior ambulacra they are remarkably long, their colour in alcohol is
whitish.

Papeete Harbour, Tahiti ; 20 fathoms. September 28, 1875.

*Cionohrissus.
Cionohrissus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. jj. 206.
This genus is specially interesting, forming as it does a transition between the Brissina
and the Pourtalesise. It has the facies of the former (PI. XXIII. fig. 1), resembling such
forms as Brissoj^sis, but having retained somewhat the cylindrical form of the Pourtalesife,
and also possessing a rudimentry anal snout (PI. XXIII. figs. 1,4, 7) immediately below
the anal system, so characteristic of the latter family, and of which the beak of the sub-
anal plastron in Echinocardium and the like is perhaps the first trace, or of which the
well-defined area enclosed by the subanal fasciole is the first rudiment, and which in the
Pourtalesise takes so extraordinary a development as an anal snout. This characteristic
feature of the Pourtalesise of a sul^anal fasciole running round the base of the anal snout
(PI. XXIII. fig. 7) is combined in Cionohrissus with a peripetalous fasciole of the Bris-
sina (PI. XXIII. figs. 1,6), and ambulacral petals recalling those of Macropneustes from
the presence of large primary ambulacral tubercles in the interambulacral areas (PI.
XXIII. fig. 6) within the peripetalous fasciole. The groove of the anterior ambulacrum
extends to the actinostome (PL XXIII. fig. 9), but is far less marked than in the Pour-
talesise, and the actinal surface is not flattened but arched (PI. XXIII. figs. 4, 5), as is

188 THE VOYAGE OF H.M.S. CHALLENGER.

generally the case in that famil)^, the actinal keel forming a prominent rounded
keel extending from the actinostome to the extremity of the anal snout (PI. XXIII.
figs. 1, 4, 5, 7).

*Ciono'brissus revinctus (Pis. XXIIL, XXXV." fig. 18 ; PL XXXIX fig. 22 ; PI. XLI.
figs. 41-43).

Cimwhritisiis revinctua, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 206.

The test of tliis species is ovoid (PL XXIIL figs. 1-5), with a moderately sunken
anterior ambulacrum (PL XXIIL figs. 3, 5,6, 9); this is flush with the test near the
apical system, deepest at the ambitus (PL XXXV. fig. 18), and extends to the actinostome.
The actinostome is anterior to the centre (PL XXXIII. fig. 3 ; the actinal plastron is
strongly arched, very prominently defined near the posterior extremity of the actinal
surface, where it forms a rounded keel (PL XXIIL figs. 1, 7) immediately below the anal
snout • this plastron is closely jjacked with tuljercles, diminishing in compactness towards
the prominent posterior lip of the actinostome (PL XXIIL figs. 1, 9).

Immediately round the actinostome on each side of the actinal plastron the ambu-
lacral areas are broad and bare (PL XXIIL fig. 9) ; the tubercles of the actinal surface
are largest next to the ambulacral area, and in the interambulacral zones ; they diminish
very gradually in size towards the ambitus (PL XXIIL fig. 1) and thence again to the
peripetalous fascicle. The tuljercles are quite uniformly placed on the whole test
(PL XXIIL figs. 1, 4, 5) with the exception of the space within the peripetalous fasciole,
where the primary tubercles of the interambulacral area greatly increase in size ( PL XXIIL
fig. 6), carrying comparatively long curved spines which completely hide the petals
(PL XXIIL fig. 2) ; the spines on the actinal surface are similar to those of the primary
tubercles within the fasciole but smaller (PL XXIIL fig. 3), while the rest of the test is
thickly covered by shorter curved spines (PL XXIIL figs. 2, 3). In alcohol the test is of
a dirty olive colour, with lighter coloured spines.

The peripetalous fasciole is narrow (PL XXIIL fig 6), and with the exception of the
re-entering angle it makes before crossing the odd anterior ambulacrum (PL XXIIL fig. 5 ;
PL XXX v.*" fig. 18) runs almost an elHptical course round the tips of the petals. The
anterior pair of petals are somewhat shorter than the posterior pair (PL XXIIL fig. 6),
the ambulacral plates being more crowded together ; the £xterior pore in the paired petals
is far larger than the interior one (PL XXIIL fig. 6).

The subanal fasciole is broad, vertically elliptical, pointed towards the actinal plastron
(PL XXIIL figs. 1, 4, 7). The anal system is small, circular (PL XXIIL fig. 4), placed
well up near the aljactinal surface. The structural apex is anterior. There are four
genital pores (PL XXIIL fig. G) enclosing a madreporic body, which extends into the odd
posterior interambulacral space.

Seen in profile the test is abruptly rounded from the actinostome ; at the anterior

REPORT ON THE ECHINOIDEA. 189

extremity it runs slightly arching to the apex, where it suddenly drops again to the anal
snout, which extends beyond the general outline, forming a sharp beak with the convex
curve extending from the actinostome to the abactinal edge of the anal snout. The spines
within the subanal fascicle form a prominent tuft, as they are somewhat more closely
packed than on the rest of the test (PI. XXIII. fig. 2). The arrangement of the large
tubercles within the peripetalous fasciole in this genus is not like that of Macroioneustes,
but it closely resembles that of some species of Metalia, and in that genus we find a very
marked tendency to form a subanal beak in the area limited by the very prominent
subanal fasciole. In Bvissopsis this snout or l)eak, as well as the development of the
pi'imary tubercles, is reduced to a minimum, while the genus (Brissopsis) still retains the
more cylindrical outline and the sunken anterior ambulacrum of Cionohrissus ; while in
some species of Metalia with the other features are associated a flattened actinal surface
as in SjKitangus proper.

Station 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' E. ; 800 fathoms ;
bottom temperature, 3 "9° C. ; mud.

Brissopsis {Hemiaster) .
Brissopds, AgassLz, 1840, Cat. Syst. Ectyp., p. 16.

Brissopsis luzonica.

Kldnia luznniea, Gray, 1851, Ann. Mag. Nat. Hist., vol. vii. p. 133.
Brissopsis luzonica, A. Agassiz, 1872, Revis. Ech., part 1, p. 95.

De Loriol has also united, as I have done, Toxohrissus (Kleinia of Gray) with Brisso2'>sis.
Loven, however, still retains Kleinia on account of the slender connection of the peri-
petalous and of the subanal fasciole ; this, as I have shown elsewhere, does not seem to be
of generic value.

Station 168, July 8, 1874. Lat. 40° 28' S., long. 177° 43' K; 1100 fathoms;
bottom temperature, 2'0° C. ; grey ooze.

Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E. ; 28 fathoms; mud.

Station 191. September 23, 1874. Lat. 5° 41' S., long. 134° 4' E. ; 800 fathoms;
bottom temperature, 3 "9° C. ; mud.

Station 203. October 31, 1874. Lat. 11° 7' N., long. 123° 7' E. ; 12 to 20 fathoms ;
mud.

Station 232. May 12, 1875. Lat 35° 11' N., long. 139° 28' E. ; 345 fathoms;
bottom temperature, 5'0° C. ; sandy mud.

Brissopsis lyrifera.

Brissm lyrifer, Forbes, 1841, Brit. Starf., p. 187.

Brissopsis lyrifera, Agassiz, Des., 1847, C. R. Ann. Sc. Nat., vol. viii. p. 15.

I am unable to distinguish specimens of this genus collected at Station 142 from

190 THE VOYAGE OF H.M.S. CHALLENGER.

Brissopsis lyrifera except by sucli indifferent characters as a somewhat more compact
test with a slight keel from the apex to the anal system, a closer tuberculation, and a
slightly sharper peripetalous fasciole ; characters which are found in specimens coming
from such distant localities as the coast of Norway and the western shore of Spain. The
great liathymetrical and geographical range of this species has already been noticed.

Station 141. December 17, 1873. Lat. 34° 41' S., long. 18° 36' E. ; 98 fathoms;
bottom temperature, 9 "7° C. ; sand and gravel.

Station 142. December 18, 1873. Lat. 35° 4' S., long. 18° 37' E. ; 150 fathoms;
bottom temperature, 8 "3° C. ; sand.

Simon's Bay ; 5 to 18 fathoms. Agulhas Bank ; 150 fathoms.

*Acrope.

Aerope, Wy. Thomson, Proc. Roy. See, vol. xxv. p. 1\\.

The genera Aerope and Aceste, first described by Thomson in the Voyage of the
Challenger (vol. ii. p. 28, fig. 99, and p. 376, figs. 95, 96), are interesting as showing the
passage oit]iQ Pourtalesia group to the Brissina among the Spatangoids, and the affinities
of those genera to such forms as Cionohrissus, Brissoj^sis, and the Schizasteridse ; while
having a simple circular actinostome, they have already a well-developed actinal plastron
and rudimentary petals at the abactinal extremity of the lateral ambulacra, while the odd
anterior ambulacral petal takes in Aceste an extraordinary development, and forms on the
abactinal surface of the test a long broad sunken petaloid ambulacrum (as deeply sunken
as in Sdiizaster) occupying nearly the whole of the abactinal surface. The peripetalous
fasciole- is quite similar in shape to that of young specimens oi Brissopsis and Hemiastcr,
in which the petals are also reduced much to the same condition as we find them in these
genera, simply double rows of pores on each side of the median line within the rudimentary
peripetalous fasciole ; one of these genera, Aerope, retaining something of the cylindrical
shape of the Pourtalesise. On the other hand the Pourtalesise, through such genera as
PalcBotropus, Genicopatagus, and Ilomolainpas, pass to the Spatangina, and through such
types as Urechinus and Cystechinus to the Galeritidge and Echinolampada3.

The striking resemblance of the young Brissopsis with its gigantic suckers in the odd
anterior ambulacrum (figured on plate xix. figs. 1, 2 of the Revision of the Echini) to the
full-grown Aerope, plainly shows the Brissoid affinities of the genus.

The deeply-sunken odd anterior ambulacrum of Aceste shows the relationship of the
genus to Schizaster, of which it also has to a certain extent the outline when seen in
profile, without having any trace, however, of the petaloid lateral ambulacra of that genus;
the only amijulacrum with double pores being the odd anterior one. The other ambul-
acra within the peripetalous fasciole have only simple ambulacral pt)res, as we find in
Echinocardium, Breynia, and Lovenia, within the internal fasciole. The course of the

REPORT ON THE ECHINOIDEA. 191

fasciole in Aceste is strikingly like that of the peripetalous fascicle of Schizaster, and it is
indeed difficult in this genus to know whether to call it a peripetalous or an internal fasciole.
Taken in connection with the course of the fasciole of Aet'oj^e and of Gualteria, in which
we find the lateral ambulacra with double pores are not in the least modified within the
fasciole, we cannot resist the conclusion that the internal fasciole is after all only a modi-
fication of the peripetalous fasciole ; what has been called an internal fasciole is in reality
only an embryonic peripetalous fasciole. If we compare the internal fasciole of Echino-
cardium with the peripetalous fasciole of a young Brissojisis, we shall find that it encloses
mainly the abactinal region of the odd ambulacral petal, and, extending only slightly
beyond the apical system, encloses only one or two pairs at the outside of the ambulacral
pores of the other ambulacra, and that it is not only with increasing age that the posterior
part of the fasciole extends further down on the sides of the test so as eventually to
enclose the whole of the petaloid portion of the ambulacra (the abactinal portion). In
Echinocardium and other genera in which the peripetalous fasciole always remains
internal, it merely does not enclose the whole of the petaloid part of the ambulacra, and
the posterior part of the fasciole remains always in close proximity to the apical system ;
the same is also the case in Breynia and Lovenia. In the former genus there is, however,
in addition what has always been called a peripetalous fasciole. I am inclined to look
upon this fasciole as a modified lateral fasciole, which takes its origin from the odd
anterior ambulacral region instead of starting, as is the case in Schizaster and other
genera, from the peripetalous fasciole in the posterior interambulacral species. I am
led to take this view from a comparison of the genera in which this so-called internal
fasciole exists for the following reasons : —

We find in Lovenia that the anterior extremity of the fasciole where it crosses the
ambulacral region is nearly lost in the midst of the minute miliaries which cover the
whole of the shallow anterior groove, and which it is difficult to distinguish from the
miliaries of the fasciole, the whole anterior groove becoming, as it were, a broad fasciole
from which the peripetalous fasciole of Breynia, where we find the same structural
features, takes its origin, and to all aj)pearances looks like a peripetalous fasciole, but is
in reality, as is shown l^y Lovenia, a lateral fasciole, taking its origin from the anterior inter-
ambulacral region. In Lovenia this lateral fasciole has more the character of a marginal
fasciole, extending but little beyond the anterior pair of ambulacral petals. This rudi-
mentary fasciole in Lovenia is interesting as showing how easily it may be for closely
allied genera to have what may seem a marginal fasciole, formed by the concentration at
the ambitus of the miliary tubercles, especially if flanked above and below by coarser
tubercles ; in fact, the whole anterior part of the test of Lovenia may be said to a certain
extent to be covered by a gigantic fasciole, highly specialised in a part of the test to form
an internal fasciole, and a short rudimentary marginal or lateral fasciole extending a short
distance along the ambitus ; while in Breyi.ia the structure of the anterior part of the test

1.92 THE VOYAGE OF H.M.S. CHALLENGER.

is not so well marked, the lateral fascicle on the contrary is better defined, and its con-
nection with the so-called internal fasciole more distinct, thus giving rise to the simul-
taneous existence of an internal and a peripetalous fasciole.

With the above limitations the peripetalous fasciole appears in all recent Spatangoids
to modify the structure of the apical portion of the lateral ambulacra. This, as has been
shown, is only true to a limited extent of the genera allied to Echinocwrdium. In some
species of Schizaster the petals lose much of the prominence they have in such species
as Schizaster cancdiferus and the like, while the occurrence of such a genus as Aceste,
in which the lateral ambulacra are not affected by the crossing of the peripetalous
fasciole, and in which the abactinal part of the lateral ambulacra retains simple
pores, as in the Pourtalesiae, goes far to show what the true nature of the internal
fasciole really is.

In Aeroj^e the peripetalous fasciole descends below the ambitus, and affects the
structure of the apical part of the ambulacra. The ambulacral pores are all double, as is
the odd ambulacrum of Aceste, but show no trace whatever of a petaloid structure ; they
retain their Holasteroid features, if we may so call the straight rows of double pores of
the ambulacral zones of some Spatangoids.

The genus Gucdteria of the Nummulite of France is the oldest of the fossil
genera in which we find the peripetalous fasciole extending across the petals so as to
become what has been called an internal fasciole. As in Aceste it does not affect sensibly
the structure of the petals. This fasciole holds an intermediate position between the true
peripetalous fasciole placed entirely outside the petals and a normal internal fasciole,
plainly showing that it is impossible to draw the line between these two kinds of
fascicles. In the Eevision of the Echini (pi. xiv. figs. 9, 11, 12), I have figured a
young Spatangoid referred with great doubt to Agassizia, in which this Gualterian
feature of the internal jjeripetalous fascicle is very marked, and in which we have a
lateral fasciole starting directly from an internal fasciole in an anterior interambulacral
area just as it would start from a true peripetalous fasciole.

*Aero2^erostrata (Pis. XXXIIL, XXXIII.'' figs. 8-12 ; PI. XXXIX. fig. 23 ; PI. XLI.
figs. 7. 8).

Aerope rostrata, Wy. Thom.son, Proc. Roy. Soc, voL xxv. p. 211; "Voyage of the Challenger,
Atlantic, vol. i. p. 381, fig. 99.

Of this species specimens of two very different sizes were collected (PI. XXIII. figs.
1-5 and 8-12); they differed considerably, in outline especially, when seen in profile,
but I am not inclined to consider them as distinct species. The large specimen measm--
ing 43 mm. in length was unfortunately so badly broken that it was impossible to
examine its structural features without danger of completely destroying it in the prepara-
tion of either the actinal, anal, or apical system. I have, therefore, limited myself to the

REPORT ON THE ECHINOIDEA. 193

detailed examination of the smaller S23ecimens for those more important regions, and
have added such structural features from the larger specimen as could be detected with-
out injuring it.

The test of the larger specimen is comparatively stout ; the abactinal region is covered
posteriorly to the peripetalous fascicle with slender slightly club-shaped spines of uniform
length (PL XXXIII. fig. 1) ; witliin the peripetalous fascicle the spines are longer, not
club-shaped, somewhat more slender, and less crowded together (PL XXXIII. figs. 1, 3).
Towards the ambitus the spines are somewhat more crowded (PL XXXIII. fig. 3), and on
the actinal side they are club-shaped, longer, stouter, and closely packed round the
exterior half of the actinal region (PL XXXIII. fig. 2). The median space is left quite
bare towards the small actinal plastron and round the actinostome ; the actinal plastron
carries a small number of large spathiform curved spines.

The test is quite cylindrical (PL XXXIII. figs. 5,5'), and the anal system (PL XXXIII.
figs. 1, 5, 7) is placed well up on the abactinal surface. Seen in profile (PL XXXIII.
fig. 3), the anterior part of the test is abruptly rounded, curving more gradually
towards the apex, which is posterior to the apical system and placed somewhat anteriorly
immediately beyond the broad peripetalous fascicle (PL XXXIII. figs. 3, 5') ; it then
curves more gradually towards the posterior extremity which is pointed.

Seen from above, the outline is rounded anteriorly (PL XXXIII. figs. 1, 2), with a
slight re-entering angle at the odd median ambulacral area. Even in this largest
specimen the gigantic ambulacral suckers (PL XXXIII. fig. 1) of the odd anterior
ambulacrum, usually characteristic in Spataugoids of tlie younger stages only, are fully as
prominent as in the smaller specimen (PL XXXIII. figs. 8, 10). There are eight of these
gigantic ambulacral feet surmounted with huge sucking disks (PL XXXIII, figs. 1, 5', G,
8, 10) ; through the genital openings pass four long slender pointed tubes (PL XXXIII.
figs. 5, 6, 8). These large ambulacral feet are placed on each side of a broad median
amljulacral zone (PL XXXIII. figs. 5, 6, 8) ; the principal jaeripetalous fascicle is very
broad near the apex, rounded posteriorly (PL XXXIII. fig. 1), and gradually slopes
towards the ambitus on the anterior part of the test (PL XXXIII. fig. 3 ; PL XXXIII.''
fig. 9). The actinostome is cii'cular, placed in advance of the centre (PL XXXIII. fig. 2 ;
PL XXXIII." figs. 8, 11), surrounded by a ring of ten large ambulacral suckers (figured by
Thomson, Voyage of the Challenger, vol. i. p. 381, fig. 99). The genital organs form
flattened clusters occupying the anterior abactinal part of the test (PL XXXIII. fig. 4).
The intestinal canal runs at first towards the anal part of the test (PL XXXIII. fig. 4),
thence it makes a complete loop to the anterior end, back again to the posterior extremity
and then runs again towards the anterior edge of the test, enclosing at the posterior end
the first part of the alimentary canal which starts from the actinostome. From tlie
second anterior loop it runs to the posterior part of the test, forming a small loop again,
before the small intestine finally passes to the anal opening.

(ZOOL. CHALI,. EXP. PAKT IX. — 18t?l) I 25

194 THE VOYAGE OF H.M.S. CHALLENGER.

The smaller specimen, measuring 20 mm. in length, is, when seen from above (PI.
XXXIII. fig. 8), less elongated posteriorly ; the anterior extremity, when seen in profile,
is more abruptly rounded (PI. XXXIII. fig. 10 ; PI. XXXIII." fig. 9) ; the peripetalous
fasciole is broader (PL XXXIII.'' fig. 10) ; the posterior extremity turns upwards, and the
spines covering the test are comparatively smaller and more distant ; the test is also some-
what more flattened on the actinal side, as shown from the end view (PI. XXXIII. fig. 11),
and from the sloping anterior part of the test (PL XXXIII.'' fig. 9).

The primary tuberculation of the actinal side (PL XXXIII.* fig. 8) is much coarser
than that of the sides of the test (PL XXXIII.^ fig. 9), and both in Aerope and Aceste
we find the proportions between the size of the ambulacral and iuterambulacral coronal
plates corresponding more with that of the normal Spatangina.

From the great elongation of the posterior part of the test, the lateral posterior
iuterambulacral, and ambulacral plates near the ambitus are greatly extended. The
apical system is compact, the madreporic body occupying the greater part of the inner
edo-es of the anterior genital plates and of the eight posterior plates ; the ocular plates
are small, and completely disconnected by the four adjoining genital plates which
occupy the structural apex.

The anal system is elliptical, slightly pointed (PL XXXIII." fig. 12) ; the anal opening
is surrounded by elongated mobile plates, while the rest of the anal system is covered by
smaller plates of a uniform size arranged in three concentric rows. The diff'erence of
level between the actinal plastron and the anterior part of the test when seen in profile
(PL XXXIIL* fig. 9) seems to be the first indication of the formation of the prominent
laliium of the true Spatangina. If in Aerope the keel of the actinal plastron (PI.
XXXIII. " fig. 8) was more decidedly indicated, we should have a well-marked lip
changing the circular actinostome of the genus into a labiate one.

This change is well shown in Aceste, in which the actinostome, while practically
circular (PL XXXIII. " figs. 5, 6), yet has a well-marked labiate actinostome (PL
XXXIII.'' figs. 2, 3), owing to the great development of the keeled actinal plastron and
the projection of the last plate adjoining the actinostome beyond its general outline
(PL XXXIII.'' figs. 2, 3).

Station 191. September 23, 1874. Lat. 5° 41' S. ; long. 134° 4' E. ; 800 fathoms ;
bottom temperature, 3 '9° C. ; mud.

Bay of Biscay and Coast of Portugal ; December 1872 and January 1873.

REPORT ON THE ECHINOIDEA. 195

*Aceste.
Aceste, Wy. Thomson, 1877, The Voyage of the Challenger, Atlantic, vol. L p. 376.

*Ac€Ste hellidifera (PL XXII. figs. 7-11 ; PI. XXXIII.'' figs. 1-7; PI. XXXIX. fig.
21 ; PI. XL. figs. 66-68 ; PI. XLI. figs. 13-16 ; PL XLIL figs. 26-28 ; PL XLIII. fig.
25 ; PL XLIV. figs. 45, 46).

Aceste hellidifem, Wy. Thomson, 1877, The Voyage of the Challenger, Atlantic, vol. i. p. 37G,
figs. 95, 66.

At first glance this appears one of the most remarkable of Sea-urchins. When seen from
the abactinal side (PI. XXXII. fig. 8) nearly the whole of the abaetinal surface is occupied
by the deeply-sunken, broad, odd anterior ambulacrum surrounded by a narrow elongated
pentagonal peripetalous fasciole, within which spring large flattened spathiform spines
curving over the few huge ambulacral suckers which fiU nearly the whole of the sunken
space of this area. The abactinal surface is quite flattened (PI. XXXIIL* figs. 4, 5), so
that when seen in profile (PL XXXII. figs. 9-11, figs. 9, 10, 11 are figured with the
actinal surface towards the upper side of the plate) the test is seen to arch regularly
towards both the anterior and posterior extremities (PL XXXIII. * fig.). The apical
system is placed just within the posterior edge of the peripetalous fasciole (PL XXXII.
fig. 8), from which the test slopes rapidly towards the actinal surface. The anterior
extremity is deeply indented (PL XXXII. figs. 7, 8, 9), the anterior part of the odd
ambulacrum running in a deep groove from the abactinal region to the actinostome
(PL XXXII. fig. 9 ; PL XXXIII.'' figs. 1, 5).

The actinal plastron is large and prominent (PL XXXIII.* fig. 4) carrying long
spathiform spines (PL XXXII. figs. 7, 9-11) ; those which cover the test are shorter and
stouter (PL XXXII. fig. 8), while those surrounding the anal system (PL XXXII.
figs. 7, 10) are long, curved, and pointed. The spines on each side of the actinal groove
are closely crowded. Seen from the extremities (PL XXXII. figs. 9, 10) the test is
seen to arch regularly from the actinal keel in the centre of the plastron to the ambitus,
which in this genus is close to the flattened abactinal surface (PL XXXII. fig. 9 ;
PL XXXIIL* figs. 4, 5) ; the test is somewhat more rounded toward the posterior end
(PL XXXII. fig. 10 ; PL XXXIII.^ fig. 4).

The enormous development of the suckers of the odd anterior ambulacrum is an
eminently embryonic feature, it exists in the youngest stages of all the Spatangoids of
which we know the development. In some species of Schizaster this character is also
found. In Aceste also, as in the Schizasteridae, we find the apical part of the anterior
lateral ambulacra made up of extremely narrow plates (PL XXXIIL* figs. 1,7), which
form the thin edge of the deep anterior groove, along the sides of which extend in Aceste
the simple anterior lateral ambulacra (PL XXXIII." figs. 1, 7), and in Schizaster proper
the more or less narrow anterior ambulacral petals placed within the peripetalous fasciole,

196 THE VOYAGE OF H.M.S. CHALLENGER.

while the short posterior lateral ambulacral petals of Schizaster are replaced in Aceste by
the three or four ambulacral plates perforated with simple pores, which are placed within
the so-called peripetalous fasciole ; this fascicle affecting in no way the structure of the
ambulacral jjlates placed within its limits.

The general outline of the test as seen both in profile and from above is strikingly
similar to that of the Schizasteridse. In fact, this genus is of the greatest interest, showing
as it does striking afiinities on the one side to the Schizasteridse and other Spatangina, such
as Brissopsis, and on the other to the Pourtalesias, not only in the structure of its ambulacral
system, but also from the position and shape of the actinostome, and the more or less
cylindrical test modified in its outline from its Schizasterid afiinities. This is well seen
in the end views of the test (PI. XXXIIL* figs. 4, 5), the anterior part of which is more
angular, as in the Schizasteridse, while the posterior is more cylindrical, as in the Pourta-
lesifB and Brissina.

Seen from above the tuberculation of the test is quite uniform (PJ. XXXIIL* fig. l),with
the exception of the ambulacral zones within the fasciole, which consist of smaller tuber-
cles. Seen from the actinal side the actinal plastron (PL XXXIII.'* fig. 2) is covered by
large primaries with a flat areolar space, with large primary tubercles extending over the
anterior part of the test mainly in the interambulacral areas adjoining the actinostome
(PI. XXXIII." figs. 3, 5). The tuberculation of the posterior part of the test is smaller,
and the tubercles are more closely packed (PI. XXXIII.'' figs. 2, 3, 4).

The anal system (PL XXXIII." figs. 2, 4) is placed on the steep sloping posterior
extremity of the test about half-way from the level of the actinal plastron to the edge of
the fasciole. It is circular, slightly pointed vertically ; the anal opening is near the lower
edge of the anal system. The anal system is covered with small elongated plates
arranged in more or less irregular concentric rows round the anal opening. Seen from
the actinal side the anal system appears on that side of the test (PL XXXIII.''' fig. 2).
The largest specimen collected measured 27 mm. in length, the smallest 14 mm.

In Aceste there are in the broad odd amljulacral field within the poriferous zone of
the abactinal system a few minute spines (PL XL. fig. 66), which are interesting as pre-
senting a modification of the tip of the spine not hitherto observed. It is a change from
the usual flattened, paddle-shaped, or club-shaped tip characteristic of the spines of so
many Spatangoids to form an umbrella-like hood. This hood is formed by a ring of large
serrations projecting far beyond the general outline, and gradually passing again both
above and below into the regular reticulation of the spine. The only similar structure
known in spines is that of the Ophiuran genera Oi^hiohdus and 02Jh{othoUa, collected by
the " Challenger" and by the " Blake," where, owing to the small number of cells composing
the spine, this umbrella-like structure is more apparent than it is in Aceste. This pecuhar
spine of Aceste is also interesting as showing a possible transition from normal to more
specialised spines, which may* in part perform the functions of pedicellariae.

REPORT ON THE ECUINOIDEA. 197

The pedicellarise of Aceste are few in number and large ; those found in the odd
ambulacral area on the abactinal side belong to the large-headed type (figured on Plate
XLIII. fig. 25 ; PL XLIV. fig. 46). Those of the test are somewhat larger, but difi"erently
shaped, and end in a short single-pointed blunt hook (PL XLIV. fig. 45).

Station 8. February 12, 1873. Off Gomera, Canaries. 620 fathoms ; sandy mud
and shells.

Station 272. September 8, 1875. Lat. 3° 48' S., long. 152° 56' W.; 2600 fathoms;
bottom temperature, 1'0° C; radiolarian ooze.

Station 323. February 28, 1876. Lat. 35° 39' S., long. 50° 47' W.; 1900 fathoms ;
bottom temperature, 0*0° C; grey mud.

Brissus.

Brwsus, Ki, 1734, Nat. Disp. Ech.

In the list of the Spatangoids of the Hamburg Museum given by Bolau, he retains the
specific names adopted by Agassiz and Desor, while adopting at the same time some of
the generic subdivisions lately proposed. It is evident from the contradictory views
of recent writers, both in fossil and recent species, that to make a satisfactory revision
of the Brissina far more material is required than at present exists in any single
museum.

*Brissus damesi, n. sp. (PL XXX." figs. 15, 16).

It is with considerable hesitation that I refer to the genus Brissus smaU specimens
collected by the Challenger at Station 75, off Fayal. The peripetalous fasciole, which in
the adult specimens of the genus is so well marked, does not exist at all in a specimen
measuring 9 mm. in length, while, as we know in other Spatangoids such as Brissopsis, it
is already at a corresponding stage remarkably well developed. In a specimen measuring
23 mm. in length, this fasciole is most indistinct, and can only with difficulty be traced
from its imperfectly developed and disconnected portions ; but where found, they occur
in the usual path of this fasciole. The subanal fasciole, on the contrary, is well developed
in the larger specimen and well blocked out in the smaller one ; the anal edge of the
fasciole is especially broad but smaller than in Brissopsis unicolor. It is possible that this
may prove to be the young of a Brissoid not yet described, but judging from the changes
due to growth in Metalia, I do not venture to do anything beyond calling attention to
the interesting points which the study of small specimens of Brissus would clear up ;
as it is evident that Spatangoid genera of an ovoid form with narrow ambulacral
petals nearly flush with the test, and with an indistinct or no peripetalous fasciole, as in
Brissits, and a subanal fasciole, are closely allied to Brissus, of which they represent the
permanent embryonic state.

Compared to a specimen of Brissus unicolor of the same size, 23 mm., this species

198 THE VOYAGE OF H.M.S. CHALLENGER.

is marked by the greater elongation of the posterior extremity of the test, the more
vertically truncated anal end, the greater size of the anal system (PI. XXX." fig. 16), the
comjiaratively narrower and stouter lateral ambulacral petals nearly flush with the test
(PI. XXX.* fig. 15), the very indistinct disconnected peripetalous fasciole, the anterior
part of the test sloping towards the ambitus quite gradually, and the regularly elliptical
actinal plastron ; while in Brissus unicolor it is broadest near the subanal fasciole, the size
of this fasciole is also comparatively much smaller than in the undoubted Brissus unicolor.
The depths at which these small specimens were found seems also to indicate either a
well-marked variety of Brissus unicolor or more probaljly the young of a hitherto un-
described species of Brissus, and it will be very interesting to see what becomes of this
rudimentary peripetalous fasciole, or whether this is only an abnormal case of development,
as this type of Brissus would if adult be closely allied to Macroiyneustes with no peri-
petalous fasciole, and also to Micraster from the slender development of its petaloid
system. This species seems to hold to Brissus much the same relations which Naco2)a-
tagus holds to Spatangus proper.

Dames has figured as Briss^is (comp. B. dilatatus, Des.) a small species, which seems in
many respects to be more closely allied to this species than any other of the genus.
Dames ^ gives no fascioles, and I am unable from his descriptions in the text or explana-
tions of the plates to determine whether the peripetalous fasciole existed or not in his
specimens. The general structure of the petals and of the tuberculation of that species
agrees well with ours, but the shape of the actinal plastron is different.

The delicate peripetalous fasciole of a species of Pe.ripneustes'^ which Dames also
figures, leads me to think that Dames' Brissus may j^ossibly be the young of this genus,
and that the species of Brissus to which I have called attention is the living
representative of this Tertiary Peripneustes, which in its turn is certainly most closely
allied to the recent Brissus.

We have already in Brissus damesi, where the petals are nearly flush with the test
and scarcely petaloid, a close approximation to such Tertiary forms as Heterohrissus of
]\Ianzoni and Mazetti, in which the petaloid extremity of the ambulacra near the
aliactinal pole differs from the rest of the ambulacral zone in having two pairs of pores,
much as we find it in the embryonic petals of Spatangus and Brissopsis, in the younger
stages of growth ; this seems to be the very type of ambulacra which we find in such genera
as Pygaster and Pileus and in the Galeritid^, only limited to the abactinal region ; the
actinal region having already assumed the Spatangoid limitations of the simple pores
which extend to their junction with these x'udimentary Galeritid petals.

' Dames, Palseontograph. xxv., III. F. i. p. 74, pi. xi. fig. 4.

- Dames, Peripneustes does uot seem to me to Ijeloiig to Peripneustes of Cotteavi, which I take to lie a true Mcoma,
the species which Cotteau figures (Echinides Tert. de St Barthelemy et AngxiilLa, 1875) being closely alUed to the
common West India species, Meorna ventricoso.

REPORT ON THE ECHINOIDEA. 199

Station 75. July 2, 1873. Lat. 38° 37' N., long. 28° 30' W. ; 450 fathoms ; sand.
Off Fayal.

Station 122. September 10, 1873. Lat. 9° 5' S. to 9° 10' S., long. 34° 49' W. to
34° 53' W. ; 350 fathoms ; mud.

Metalia (Brissus).

Plaijionotus, Agassiz, 1847 («o« j\Iuls., 18i2).
Metalia, Gray, 18.55, Cat. Rec. Ech.

Metalia maculosa.

Echinus maculosus, GmeL, 1788, Linn. Syst. Nat.

Metalia maculosa, A. Agassiz, 1872, Eevis. Ech., part 1, p. 114.

Stationl88. Sept. 10, 1874. Lat. 9° 59' S., long. 139° 42' E.; 28 fathoms; mud.
Metalia pectoralis.

Echinus grandis, GmeL, 1788, Liun. Syst. Nat.

Metalia pectoral is, A. Agassiz, 1872, Revis. Ecli., part 1, p. 144.

Fragments of the abactinal surface of the test of a specimen of this species were
collected off Bahia, which show that the large tubercles within the peripetalous fasciole
carry large long curved spines like those of Breynia, Lovenia, Maretia, Eupatagus and
the like. The spines near the posterior extremity and close to the ambitus, as well as on
the actinal side, are stouter and longer than the uniform coating of spines covering the
greater part of the abactinal surface of the test outside of the peripetalous fasciole. The
size of the tubercles indicates well in a general way the proportion and character of the
spines. The colour of the spines in alcohol is a pinkish buff.

Off Bahia.

Schizaster.
Schizaster, Agassiz, 1836, Prod.

It will evidently be extremely difficult when including the fossil species to separate
satisfactorily many of the fossil species of Lvnthia from Schizaster, the passage being very
gradual from species having the typical facies of Brissus with the lateral fasciole of
Agassizia and Schizaster, to species in which the sunken petals, more or less broad
and sunken anterior ambulacrum, and the general outline of the test approach the more
or less globular species of Schizaster. Yet among the recent forms the only two species
known seem to indicate very distinct generic differences. See more specially the descrip-
tion of a very typical and most interesting new species of Linthia, by Mr E. A. Smith
in Ann. and Mag. Nat. Hist, 1878, vol i. p. 67.

From the species of Linthia, combining many of the characters of Schizaster, there is

200 THE VOYAGE OF H.M.S. CHALLENG'EE.

on the one hand but a step to species which have been associated with Prenaster, leading
to Pencosmus, and which in their turn lead most naturally to Meter opneustes, and of
such types as Brissomorpha of Laube, in which the peiipetalous fasciole has completely
disappeared ; while in another direction the structure of these species would also indicate
affinities to such genera as Faorina, which in their turn lead to such genera as Cyclaster,
to which many fossil species are frequently referred without reference to the presence or
absence of a peripetalous fasciole.

We have not as yet sufficient data, for the study of the young Schizaster, to enter
into very detailed comparisons, but the following points are interesting as throwing
additional light on the affinities of the genera allied to the Schizasteridag : —

The limits which have been assigned to the genera closely allied to Schizaster are
very unsatisfactory, and the generic characters by which different species are assigned to
these genera or sub-genera pass so gradually one into the other, not merely among the
recent species, but especially when we come to include the fossil species, that the task of
properly limiting them appears hopeless, although these characters are convenient as
subdivisions according to which we may associate groups of species.

Take, for instance, species like Schizaster canaliferus, with a broad, deep sunken
anterior ambulacrum, a short posterior lateral pair of ambulacra, and a well-developed
lateral fasciole extending under the anal system, and they seem to form a well-marked
group when contrasted to species like Schizaster moseleyi, in which the test is compara-
tively flattened, the anterior ambulacrum broad but shallow, and where no lateral fasciole
exists, having the course of that of Schizaster canaliferus, or but slight traces of it, exist
as an indistinct branch of an anal fasciole ; while in other species Schizaster fragilis and
Schizaster philippii, having the same general facies as Schizaster moseleyi, we have not
thus far found the variation in the course and extent of this lateral fasciole, but it is quite
as well defined as in Schizaster canaliferus ; while again such a group as that to Avlii(;h
Schizaster ventricosus and Schizaster gibherulus belong has the more deeply sunken
ambulacra of Schizaster canaliferus, without a lateral fasciole but very distinct anal
fasciole, and yet has the low flattened test of Schizaster pnhilippii and Schizaster fragilis.

The small specimens (from 12-19 mm.) of young Schizaster ventricosus, Schizaster
japonicus, and Schizaster moseleyi collected by the Challenger, show already the specific
characters sufficiently well developed to enable us readUy to assign them to their respective
species ; the difference in outline in the test is, however, quite marked, and the test of all
these species is much more globular than in the adult, and in one specimen of Schizaster
moseleyi the test was, as in young specimens of Brissop)sis, nearly globular, with a slightly
indented peripetalous fesciole, and the suckers of the odd anterior ambulacrum already
developed out of proportion to the rest of the test. The anal fasciole is quite well marked
in the smallest specimens of Schizaster ventricosus, but the latero-anal fasciole of Schizaster
japonicus is occasionally interrupted on the sides of the test in small specimens, evidently

REPORT ON THE ECHINOIDEA. 201

showing that the lateral fasciole is an extension of the anal fasciole, and that as far as we
know the lateral and anal fascioles, when they appear independently or united, are of
greater permanence than when the anal fasciole appears as a branch of the subanal fasciole.
These young Schizasteridaj show very plainly that such genera as Acestc are strictly
embryonic Schizasteridse ; that is, they retain as the young of Schizaster very rudimentary
posterior lateral ambulacral petals, the odd anterior ambulacrum occupies the greater part
of the abactinal surface of the test, the ambulacral suckers of this odd ambulacrum retain
the gigantic size for which they are marked in the younger stages, and the peripetalous
fasciole follows closely the lines di-awn from the extremities of the petals. At a stdl earlier
stage when Schizaster is more globular, it assumes a still more embryonic stage as the
young of Brissojysis, that is, it passes then through what might be called its Hemiaster
stage, and of this stage, when the actinostome is as yet not developed, Aerope is the
representative at the present day ; having the prominent peripetalous fasciole, the greatly
developed odd anterior ambulacrum, but slightly sunken at first in the Aceste stage, and
scarcely flush with the test in the Hemiaster stage, with its gigantic ambulacral suckers,
and the more or less cylindrical shape so characteristic of all young Spatangoids. To a
certain extent Agassizia may be regarded also as an embryonic type ; it retains the
globular shape of young Spatangoids, and the structure of the petals is embryonic in part.
The presence of a well developed lateral fasciole dates back to the cretaceous Prenaster.
The unsatisfactory nature of the characters derived from the extent and course of the
lateral fasciole is well showTi from the subdivisions of Faorina attempted by Troschel,
which are based mainly on the fascioles. Although the presence of a peripetalous fasciole
appears greatly to modify the character of the abactinal part of the ambulacra, yet we are
not able to make any classification of the Spatangoids based on the presence or absence of
fascioles alone which corresponds in any way to the other structural afiinities. The
Prymnodesmians of Loven (Spatangoids with a subanal fasciole) unite such widely distant
types as Palceotroinis, Spatangus, Brissus, and Breynia ; while among the Prymnadetes
we find Hemiaster, Desoria, and Schizaster, and it is often very difficult, as in the case of
Urechinus and many fossil genera, to decide whether they belong to the Adetes or either
of the other groups, and we find in the Pourtalesise, for instance, otherwise closely allied
genera which would in this character alone he i^laced either in the one group or the
other.

Schizaster fragilis.

Brissus fragilis, Diib. o. Kor., 1844, Skand. EcHn., p. 280.
Schizaster fragilis, Agassiz., 1847, C. R. Ann. Sc. Nat., vol viii. p. 22.

The Challenger collected this species ofl" the coast of Nova Scotia. It has also been
dredged by the United States Fish Commission in the Gulf of Maine. This species like
Brissoixsis lyrifera and S2X(taiigus raschi, has an extensive geographical range in the

(ZOOL. CHALL. EXP. — PART IX. — 1881.) I 26

202 THE VOYAGE OF H.M.S. CHALLENGER.

Atlantic, a,s the accompanying widely-separated localities where it was collected by the
Clialleno-er indicate.

Station 49. May 20, 1873. Lat. 43° 3' N., long. 63° 39' W. ; 83 fathoms ; bottom
temiJerature, 1'8° C. ; gravel, stones.

Station 142. December 18, 1873. Lat. 35° 4' S., long. 18° 37' E. ; 150 fathoms;
bottom temperature, 8 "3° C. ; sand.

''Schizaster japonicus (PL XXXVI. figs. 8-13 ; PL XLIII. fig. 26 ; PL XLV.
figs. 7-10).

Scliizaster jajMiiicus, A. Agassiz, 1879, Proc. Am. Acad., vol. xiv. p. 212.
In this species the posterior lateral ambulacra (PL XXXVI. fig. 11) form a more
acute angle with the longitudinal axis than in Schizaster ventricosus ; it has also a very
distinct latero-anal fascicle (PL XXXVI. fig. 12), a smaller anal opening, and a more
pointed posterior extremity. A prominent keel in the median posterior interam-
bulacrum forms a high crest at that end of the test (PL XXXVI. fig. 12), while
Schizaster ventricosus is remarkable for its comparatively flattened and rounded
posterior extremity (PL XXXVI. figs. 1, 3).

The ambulacra are all more deeply sunken, much as in Schizaster cancdiferus and
Schizaster fragilis. The test is highest immediately behind the apical system in the odd
interambulacrum (PL XXXVI. fig. 12). These characters are early developed, as a
comparison of young specimens of Schizaster ventricosus and Schizaster jcqw7iict(s,
measuring respectively one-third and half an inch in length, readily shows. The
peripetalous fasciole is broad, and made up of triangular-shaped l^ands at the angles, and
especially at the points in the median ambulacral spaces ; it runs nearly straight across
the odd interambulacrum from the extremity of the posterior petals.

There are two large genital openings in the posterior lateral ambulacra and a minute
one in the left anterior one, while in Schizaster ventricosus these three are equally
developed (see Revis. Ech.). The apex is also more central in this species, and the
peripetalous fasciole less angular than in Schizaster ventricosus. The lateral fasciole
(PL XXXVI. fig. 1 2) extends under the anus, it is narrow and sharply marked ; the
posterior ambulacra are proportionally wider, the outline more angular, the test swollen,
and pointed at the posterior extremity when seen from above (compare PL XXXVI.
figs. 11 and 12).

This form of Schizaster, and such forms as Moiropsis claudicans, readily pass on
the one side into Moira, with its still more deeply sunken ambulacral plates, and
comparatively ovoid and angular test, and into those fossil species of Schizaster, which
have generally been associated with Linthia.

It is interesting to note with reference to the development of the fascioles, that in
a young specimen measuring 12 mm. in length the lateral fasciole is indistinct near its

REPORT ON THE ECHINOIDEA, 203

junction with the peripetalous fascicle. The arrangement of the spines is somewhat
peculiar ; in addition to the usually larger spines found in Schizasteroids on the edges
of the petals and of the odd ambulacral groove, tufts and patches of considerable
size of similar larger spines are found as in other genera, not only on each side of
the anal system and at the extremity of the actinal beak (PL XXXVI. fig. 9), but also
in the ambital region of the lateral anterior iuterambulacral areas (PL XXXVI.
figs. 8, 10), and in the anterior half of the lateral posterior iuterambulacral areas from
the posterior edge of the anterior lateral petals to the edge of the test (PL XXXVI.
fig. 10). The rest of the abactinal surface of the test is covered with short spines of
nearly uniform length and size. On the actinal side the spines are longer, coarser, and
more distant (PL XXXVI. fig. 9), corresponding to the tuberculation of that region (PL
XXXVI. fig. 13).

Tlie pedicellarije of Schizaster japonicus (PL XLIII. fig. 26 ; PL XLV. figs. 7-10),
are stout-headed and stout-stemmed, few in number, scattered irregularly on the test,
and stand out prominently from the test owing to their dark violet colour.

Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E. ; 28 fathoms;
mud.

Station 233&. May 26, 1875. Lat. 34° 20' N., long. 133° 35' E. ; 15 fathoms;
mud.

Off Yokohama ; 8 to 1 4 fathoms.

Hong Kong, outside harbour ; 10 fathoms. December 22,1874. Kobi, Japan ; 8 to
50 fathoms. May 18 and 19, 1875.

"^Schizaster moseleyi, n. sp. (PL XXXVI. figs. 14-16).

The general facies of this species recalls Schizaster frag iUs and Schizaster 2-)hiUx)pii ;
it has like these species a flattened test, lateral ambulacra only slightly sunken, a
broad odd anterior ambulacrum with angular edges on the abactinal side and three
genital openings. It has, however, like Schizaster gibherulus and Schizaster ventricosus
no latero-anal fasciole, some specimens showing a -delicate and most indistinct anal
fasciole. The position of the apex is intermediate between that which it occupies in such
species as Schizaster fragUis and in Schizaster canaliferus. The colouring is like that of
Schizaster pihilipjni (when in alcohol), of an olive green.

In young specimens measuring about 1 5 mm. the outline is much the same as in the
adult (55 mm.); the posterior extremity of the peripetalous fasciole is more pointed
owing to the small size of the posterior pair of lateral ambulacra, which are reduced to
two or three pairs of pores ; with increasing size this part of the fasciole broadens in pro-
portion to the increase in width of the posterior lateral ambulacra.

Station 311. January 11, 1876. Lat. 52° 50' S., long. 73° 53' W. ; 245 fathoms;
bottom temperature, 7 '7° C. ; mud.

204 THE VOYAGE OF H.M.S. CHALLENGER.

Station 307. January 4, 1876. Lat. 49° 24' S., long. 74° 23' W. ; 147 fathoms;
bottom temperature, 7 '6° C. ; mud.

Station 309. January 8, 1876. Lat. 50° 56' S., long. 74° 15' W. ; 40 to 140 fathoms;
mud.

Station 310. January 10, 1876. Lat. 51° 30' S., long. 74° 3' W. ; 400 fathoms ;
bottom temperature, 7 '9° C. ; mud.

Station 305. January 1, 1876. Lat. 47° 48' S. ; long. 74° 48' W. ; 120 fathoms;
mud.

Off London River, Kerguelen ; 110 fathoms.

Off Christmas Harbour, Kerguelen ; 120 fathoms.

Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E ; 1375 fathoms ;
bottom temperature, 1-5° C. ; globigerina ooze.

Schizaster ventricosus (PL XXXVL figs. 1-3).

Schimster ventricosus, Gray, 1851, Ann. jNIag. Nat. Hist., vol. vii. p. 1.33.

As I refer so frequently to this species in the comparative descriptions of the different
species of Schizaster, and as it is most typical of a special group of species, I have given
figures of it to facilitate the comparisons and to illustrate the affinities of the different
species of Schizasteridse.

Station 232. May 12, 1875. Lat. 35° 11' N., long. 139° 28' E. ; 345 fathoms;
bottom temperature, 5"0° C. ; sandy mud.

Periaster (Schizaster).
Periasfer, D'Orb., 1854, Pal. Fran^. Terr. Cret, torn. vi. p. 269.

''Periaster limicola (PI. XXXV.'= figs. 1-4 ; PL XXXIX. fig. 38 ; PL XL. figs. 1-6).

Schizaster {Periaster) limicola, A. Agassiz, 1878, BuU. Mus. Comp. Zool., vol. v. p. 293, pL iii.

I cannot distinguish the specimens collected by the Challenger (Station 188) from the
specimens dredged ofi" the mouth of the Mississippi. The latter are very much larger
than the Challenger specimens. This species was accidentally described first from
specimens dredged by the " Blake ; " the only marked difference in the specimens of
the "Blake" and "Challenger" is in the course and distinctness of the anal fasciole, which
is more indistinct in specimens collected by the latter, and difficult to trace in the midst of
the small tubercles covering the anal extremity of the test.

REPORT ON THE ECHINOIDEA. 205

The two Challenger specimens were still covered with spines at the time I examined
the " Blake " Echiuoidea, and it was only subsequently that I became aware of their
identity. On the actinal plastron the primary spines are spathiform, the spines of the
anterior part of the test of the actinal and abactinal surface are longer than the others,
curved, gradually diminishing in size towards the apical system, though longer again on
the edge of the petals ; the sides of the test are covered with smaller spines increasing
in length again towards the actinal keel and the anal face of the test. Within the
peripetalous fasciole the spines are of an ashy violet tint and a silvery dull white over
the rest of the test.

The facies of this species seems to indicate closer affinities of the genus Periaster
to Schizaster than to Linthia with which I was (as Desor before me) inchned to
associate it.

Station 188. September 10, 1874. Lat. 9° 59' S., long. 139° 42' E. ; 28 fathoms;
mud.

*Moiropsis (Moira) n. gen.

This genus has, like Moira, a peripetalous fasciole forming a seam immediately on the
edge of the petals ; it has also, like it and other Schizasteridee, a weU developed latero-anal
fasciole, the odd anterior ambulacral petal well limited and similar to the others, and
the petals sunken. This genus is intermediate between Moira and Schizaster, and shows
that the affinity of these genera is far closer than had been suspected.

'■"Moirojms daudicans (PI. XXXVI. figs. 4-7; PI. XL. figs. 51-53).
Schizaster daudicans, A. Agassiz, 1879, Proc. Am. Acad, vol. xiv. p. 211.

This pretty little Schizaster is well characterised by the high posterior test, the
vertical posterior extremity extending into a prominent beak (PI. XXXVI. fig. 6), the
sharp, narrow, clear-cut lateral fasciole, the narrow and deeply-sunken ambulacral petals
fringed by an indistinct peripetalous fasciole (PI. XXXVI. figs. 4, 7), its narrow actinal
plastron (PL XXXVI. fig. 5), the position of the anal opening immediately under the
abactinal edge of the posterior interambulacral keel, and the close uniform tuberculation of
the test above the ambitus. The outline of the test is cordate, seen from the actinal side
(PL XXXVI. fig. 5) broad, the ambulacral areas bare ; the actinostome placed close to the
anterior edge, about one-fourth of the length of the test. The peripetalous fasciole crosses
the odd posterior and lateral posterior interambulacra close to the apical system, following
the edo-e of the petals it crosses the anterior iuterambulacrum halfway in the petal and
encloses the whole of the short anterior petal, which is shorter than the lateral anterior

206 THE VOYAGE OF H.M.S. CHALLENGER.

ambulacra as in some of the fossil species, but longer than tlie posterior lateral ones.
There are two indistinct genital ojDenings in the posterior lateral ambulacra.

Seen in profile the abactinal outline of the test is nearly parallel to the actiual surface
from the posterior extremity to the apical system ; from there, however, it slopes rapidly
towards the rounded anterior extremity forming the aml)itus. The tuberculation of the
actinal surface is most prominent towards the actinostome in the interambulacral areas,
diminishing gradually in size towards the ambitus, where it runs into the granulation of
the abactinal surface and sides of the test.

The beak formed by the jjosterior extremity of the actinal plastron is fully as much
developed as in some species of Echinocardium ; the lateral fasciole is sharply defined,
and its course well marked as it passes under the anal system about halfway from the
ambitus on the posterior extremity. This species recalls more in its outline some of the
Tertiary species which have like it a somewhat prominent beak, such as Schizaster
archiacii and Schizaster vicinalis, and the like, in spite of the great difierence in the
course of the peripetalous fasciole.

This species is also interesting as it shows how in Schizaster proper the sunken
anterior ambulacrum is related on the one side to such genera as Brissus and the like in
which the odd anterior ambulacrum is not petaloid, and on the other with genera such as
Moira in which the ambulacra are all deeply pouched, while the equal development
of the odd anterior petal with the others, is on the contrary a feature characteristic of
genera not in the least closely allied to the Schizasteridae such as Spatangus and the like.
The sunken petals and the lateral fasciole of this species show its affinities to Tripylus in
which we have, however, only the four lateral petals deeply sunken, the odd anterior one,
on the contrary, being flush with the test as in Fetor ina and Linthia. This combination
of the lateral and perij)etalous fasciole with either more or less sunken lateral and odd
ambulacral petals shows unsuspected affinities between such very widely differing
genera as Agassizia on the one side, and Moira on the other, which are readily
understood when we use as terms of comparison allied forms to either extreme, such as
Brissus, Faorina, Brissopsis, Hemiaster, RJtinohrissus, Linthia, and Schizaster on the
one side, and Moira, Moiroims, Tripylus, Hemiaster, Faorina, and the like on the
other.

Station 192. September 26, 1874. Lat. 5° 42' S., long. 132° 25' E. ; 129 fathoms;
mud.

The preceding enumeration includes 139 species of Echinids, of which 87 were known
before and 52 are new species. The species collected are distributed as follows: — 11
Cidaridse (of which 3 are new species), 2 Salenidse (1 new species), 6 Arbaciadse (1 new
species), 7 Diadematidte (3 new species), 12 Echinothuridse all of w^hich are new to science,
10 Echinometradae (no new species), 16 Temnopleuridfe (3 new species), 11 Triplechinidse

REPOKT ON THE ECHINOIDEA. 207

(1 new species), 15 Clypeastridfe (all known species), 2 Nucleolidas (1 new species), 13
Pourtalesia3 (12 new species), 6 Ananchytid^ (5 new species), 10 Spatangina (all pre-
viously known species), 18 Brissiua (10 new species).

GEOGRAPHICAL AND BATHYMETEICAL RANGE.

At the time I published the Revision of the Echini (1872-74) there were enumerated
207 species distributed in 89 genera. This was a very material reduction of the number
of species formerly recognised, and yet it included a couple of the deep-sea species dredged
by the "Porcupine" and all the deep-sea species (13) discovered up to that time by
Mr Pourtales. Of the strictly littoral species there were not known at that time more
than 192 species and 74 genera. In the general list now given there are 297 species and
107 genera enumerated, making in all 90 species and 25 genera added to the former
list in spite of the reduction in number by the cancelling of a few nominal species of
the older lists ; not more than ten well-characterised species have been added by various
writers to the list of the Revision in addition to the species discovered by the deep-sea
dredging expeditions.

This leaves 80 deep-sea species described since those of Mr Pourtales ; of these 49 were
discovered by the " Challenger," and 41 by the "Porcupine," "Josephine," and "Blake." Or
about one-third of the whole number of known species of Echinoidea have been discovered
since the days of deep-sea dredgings ; of these 5 were brought to light by the " Josephine,"
the same number by the "Porcupine " ; twenty-eight have thus far been described from
the Coast Survey Expeditions ("Blake," "Bibb," and "Hassler"), and 49 from the
" Challenger."

One new genus was discovered by the "Porcupine," and one by the "Josephine," nine
by the Coast Survey Exj^editions, and 15 by the " Challenger." But in addition to these
new genera, 7 genera previously only known from fossils, were added to the present
list, either by the "Blake" (3), "Challenger" (2), "Josephine" (1), or "Porcupine" (1).

The following compendium of our knowledge of the geographical, bathymetrical, and
geological range of the recent Echinids will be found convenient for reference in the
discussions which foUow.

The only species which are not included in this list are those of the " Gazelle." A
preliminary report of these Echinids has been published by Dr Studer,^ and 1 have in
the descriptions of the species of the " Challenger " referred to the species which 1 con-
sider as identical or closely allied. The species described by Studer are from compara-
tively shallow water, and probably all belong to the Littoral Fauna.

1 Monatsber. der K. AkaJ. J. W., Berlin, Jidi 1876.

208

THE VOYAGE OF H.M.S. CHALLENGER.

List of the known Species of Recent Echinoidea, showing theie, Range in Depth, and their
Principal Localities ;^ and giving an Indication of the Geological Distribution
OF THE Genera.

Explanation of Letters, &c.

B. " Blake " and United States Coast SiU'vey

Expeditions.

C. " CliaUenger " Expedition (EngHsli).
J. " Josephine " „ (Swedish).

P. " Porcupine " Expedition (English).
Val. "Valorous" „ ( „ ).

* Species discovered by the Challenger.
X Previously kno\vn species collected hy the Challenger.

In the Bathymetrical Range.

— 250 B. means that the species extends from the shore to 250 fathoms, and that the greatest depths have been determined by the
B. = " Blake " Expedition.

410-500 C. gives the upper and lower limits as determined by the C. = " Challenger " Expedition.

[ 180 J. that the species has only been collected at that depth by the J. = " Josephine " Expedition, and that nothing further is
known of its bathymetrical range.

Range

in Depth.

Principal Localities.

Tertiary.

Cretaceous.

Jurassic.

Fathoms.

DESMOSTICHA, Hajckel.

CiDARiDiE, MiiUer.

GoNiociDARlD^, Hseckel.

Cidaris, Kl.

'Red Sea; Mauritius; Cape of

Eoceue ; Mio-
cene ; Plio-
cene.
-Austria; Switz-
erland; Malta;
Italy ; India ;
Austi-alia.

C. metularia, Bl.
C. thouarsii, Val.

—

Good Hope ; East India i
Islands ; Sandwich Islands ;
_ Fiji Islands.
Panama ; Gulf of California.

_ Upper Chalk.
'Lower Chalk.

Jura; Lias.
Trias.

X C. tribuloides, BL

-250 B.

South Carohna ; Florida ;
Brazil ; Cape Pahnas.

Dorocidaris, A. Ag.

^

D. bartktti, A. Ag.

76-398 B.

Caribbean Islands.

*i). blakii, A. Ag.

158-450 B.

Florida ; Caribbean Islands.

*Z'. hracteata, A. Ag.

15-100 C.

Amboyna.

Eocene.

1 Chalk.

' Norway ; Shetland Islands ;

-North America;

Jura.

Mediterranean ; Canaries ;

Austria.

X D. papillata, A. Ag.

-874 B.

■I Florida ; Caribbean Islands ;
St Paul Rocks ; La Plata ;
Philippines.

Phyllacanthus, Br.

-|

X P. annulifera, A. Ag.

-28 C.

Australia; Philippine Islands;
Torres Straits.

X P. baculosa, A. Ag.

-102 C.

Red Sea ; Zanzibar ; Mauritius ;
Philippines.

Nummulite.

P. dubia, Br.

Zanzibar ; Boiiin Islands ;

India ; Aus-

)

"~"

Australia.

- tralia; Malta;

} Chalk.

Oolite

X P. gigantea, A. Ag.

—

Sandwich Islands ; Mamitius.

France; North

)

(RlMboeidaris). \

P. imperialis, Br.

—

( Red Sea ; East India Islands ;

} Australia.

( Society Islands ; East India

America.

X P. verticillata, A. Ag.

-8C.

< Islands ; Australia ; Sand-
( wich Islands ; Torres Straits.

Stephanocidaris, A. Ag. ■

S. hispinosa, A. Ag.

—

Australia ; Malacca.

' For detailed lists of localities see A. Agassiz, Revision of the Echini, part 1 ; Mem. Mus. Comp. Zool., vol. iii. ; lU. Cat., No. 7.

REPORT ON THE ECHINOIDEA.

209

Range

in Depth.
Fathoms.

Principal Localities.

Tertiary.

Cretaceous.

Jurassic.

Porocidaris, Des.

*P. elegans, A. Ag.

410-500 C.

( Philippines ; New Guinea ; New
I South Wales.

Eocene ; Mio-
cene.

1
I

Jura.

P. purpurata, Wy. Thom.

[542 P.

( Rockall ; Shetland ; Faroe
( Islands.

"France; Egypt;
(Num.)India.

1 "

P. sharreri, A. Ag.

123-351 B.

Cai-ibbean Islands.

J

Gmiiocidaris, De».

' Falkland Islands ; Patagonia ;
Natal ; Zanzibar ; Marion

X G. canaliculata, A. Ag.

-1975 C.

Islands, Kerguelen ; Aus-
tralia ; Heard Island — Ant-
L arctic.

*(?. fiorigcra, A. Ag.

100-129 C.

( Philippines ; Indian Archi-
pelago.
Australia ; East Indies ; Tas-

(?. geranioides, Agass.

mania.

X (?. tuharia, Liitk.

-40 C.

Australia ; Tasmania ; New
South Wales.

Salenid.-e, Agass.

Salenia, Gray.

,.

& gcesiana, Lev.

[180 J.

Caribbean Islands.

*6'. hastigera, A. Ag.

100-1850 C.

C Philippines; Kermadec; Indian
< Archipelago ; Bay of Biscay

Eocene ; Mio-

[" Lower Chalk.
Upper Chalk.

[-Upper Jura.

( and Coast of Portugal.

cene.
"France; Aus-
tralia.

<j France ; Eng-

6'. }Xtttersoni, A. Ag.

175-450 B.

Caribbean Islands.

land ; Ger-
^ many.

1

C Straits of Florida ; Caribbean

J

X S. varispma, A. Ag.

60-1675 B.C.

< Islands ; North Brazil ; Ascen-
( sion; Azores; Canaries.

J

Aebaciad^, Gray.

Arhacia, Gray.

-

.4. cmstralis, Trosch.

—

Australia (?).

X.4. dufresnii, Gray.

-175 C.

Patagonia ; Chili ; Nightingale
Islands.

X .i4. 7ii(/ra, A. Ag.

i Patagonia; Chili; Peru; PhUip-
( pines.
Long Island Sound to West
Florida; Yucatan.

Late Tertiary.

A. punctulata, Gray.

-125 B.

"North America.

xA.jmstidosa, Gray.

—

Mediterranean; Liberia; Brazil.

yl. spatidigera, A. Ag.

—

Chin ; Peru.

.4. stellata, Gray.

—

Panama ; Gulf of California.

Podocidaris, A. Ag.

•^

*P. prionigera, A. Ag.

1050-1075 C.

Philippines ; New Guinea.

—

^Magnesia;

X P. sculpita, A. Ag.

138-390 B.

^ Straits of Florida ; Caribbean
( Islands.

—

Codiopsis.

P. sciUata, A. Ag.

[580 B.

Caribbean Islands.

^

Ctelopleunis, Agass.

Eocene ; Crag.

C. floridanus, A. Ag.
X (7. maillardi, A. Ag.

56-1323 B.
82-102 C.

( Straits of Florida ; Caribbean
Islands.
Bourbon ; Philippines ; Am-
( boyna ; Indian Archipelago.

North America;
> France; Eng-
land ; Italy ;
(Num.) India.

(ZOOL. CIIALL. EXP. PART IX. 1881.)

127

210

THE VOYAGE OF H.M.S. CHALLENGER.

Range
in Depth.
Fathoms.

Principal Localities.

Tertiary.

Cretaceous.

Jurassic.

DiADEMATID.'E, PeteiS.

Diadeina, Schyuv.

D. mexicanum, A. Ag.
X D. setosum, Gray.

-115 B.

CAcapulco; Cape St Lucas.

West India Islands ; Bermudas ;

J Cape Verde Islands ; hulian

1 Ocean ; Japan ; Sandwich

Islands; Fiji Islands; Philip-

1^ pines.

Centrostephanus, Pet.

0. coronatus, A. Ag.
C. loixgispimis, Pet.
C. Todgersii, A. Ag.

Cape St Lucas.

Palermo ; Canary Islands.

Australia ; New Caledonia.

*Aspidodiadema, A. Ag.

■f-A. microtviercidatum,
A. Ag. ]

i-A. tonsum, A. Ag.
A. antillarum, A. Ag
A. jacobyi, A. Ag.

356-2225 C.

100-1700 C.

451-1200 B.

95-287 B.

( North Brazil ; Tristan da
} Cunha; Macio; Chili; Juan
( Fernandez.

Philippines; Kermadec; Macio.

Caribbean Islands.

Caribbean Islands.

JEchinothrix, Pet.
X E. calamaris, A. Ag.

E. desorii, Pet.
X E. tiircarum, Pet.

[ Society Islands ; East India
■; Islands; Philippine Islands;
( Kandavu Reef.
( Red Sea ; Fiji Islands ; Sand-
( wich Islands.
C Sandwich Islands; Fiji Islands;
J Japan ; East India Islands ;
' Red Sea; Zanzibar; Kandavu
L Reef.

*Micropyga, A. Ag.

*Af. tuhercxdatum, A. Ag.

100-610 C.

Philippines ; Fiji Islands.

Astropyga, Gray.

.4. elastica, Stud.
X yl. jjKit)Mia(rt, Agass.

^. radiata, Gray.

[20
-49 C.

New Britain.
( Panama; Gulf of California;
) Torres Straits ; Honolulu.
1 Zanzibar; East India Islands;
( Philippines.

EcHiNOTHURiD^jWy. Thorn.

^st?ie?iosoma, Gruhe.

*^. coriaceum, A. Ag.

A. fenestratum, W. Thorn.

:'=^. gracile, A. Ag.
*J. grubii, A. Ag.

^. hystrix, A. Ag.
*^. pellucidum, A. Ag.

240-315 C.

[445 P.

150-255 C.
[IOC.

100-445 B. P.
100-129 C.

Fiji Islands.
(•Rockall; Bay of Biscay; West
\ Coast Portugal.

Philippines ; New Zealand.

Philippines.
( Florida ; Rockall to Bona ;
-< Caribbean Islands; Cape
( Finisterre.

I Philippines ; Indian Archi-
\ pelago.

...

f Chalk.
J England
1 {Echi tlm-

[ ria).

-'=^. tessellatum, A. Ag.
yl. varimn, Grube.
^. reynoldsi, A. Ag.

100-115 C.
180-375 B.

Philippines.

China Seas ; Java Seas.

Caribbean Islands.

REPORT ON THE ECHINOIDEA.

211

Phormosoma, Wy. Thorn.

*P. asterias, A. Ag.
■•'P. bursaria, A. Ag.

■•'P. hoplacantha, Wy. Th.
P. luculentum, A. Ag.

P. placenta, Wy. Thorn.
■'•P. rigidum, A. Ag.
■fP. tenue, A. Ag.
*P. uranus, Wy. Thorn.

P. sigshii, A. Ag.

P. petersi, A. Ag.

ECHINOMETRAD^, Gray.
Colobocentrotus, Br.
C atratus, Br.
C. mertensii, Br.

Heterocentrotus, Br.
X if. mammillatus, Br.

X iJ. trifjonarius, Br.

.Bc/imome<r(i,Eondel.(Breyn. )

X .E. lucunter, Bl.

J?. niacrostoma, A. Ag.
i^. ohlonga, Bl.

X £. suhangidaris, Desml.

J5^. fCTO hnmti, A. Ag.
£■. viridis, A. Ag.

Parasalenia, A. Ag.
P. gratiosa, A. Ag.

Stomopnexistes, Agass.
S. variolaris, Agass.

Strongylocentrotus, Br.

iS. (i^6!(s, A. Ag.

S. armiger, A. Ag.
S. depressus, A. Ag.

X & driibachiensis, A. Ag.
X S. eurythrogrammuSjA. Ag.

Eange
in Depth.
Fathoms.

Principal Localities.

[2160 C.
255-1050 C.

410-1375 C.
255-1060 C.

500-800 P.
700-1400 C.
1875-2750 C,
1000-1525 C,

120-1242 B.

399-1224 B.

-18 C.

-250 B.

-35 C.

Juan Fernandez to Chili.

Japan ; Philippines.
( Japan ; New South "Wales ; Juan
) Fernandez to Chili.
( Philippines ; Indian Archi-
( pelago.

( West Coast of Scotland and
( Ireland.

New South Wales.

! Sandwich Islands to Low Archi-
pelago ; Japan.
Portugal ; Azores.
( Caribl3ean Islands ; Atlantic
I Coast of U.S. (Mid. States).
( Caribbean ; Atlantic Coast of
\ U.S. (Middle and Southern
( States).

Zanzibar ; Java ; Sandwich

Islands; ChUi.
Bonin Islands; Australia.

( Sandwich Ids. ; E.India Ids. ; Red
I Sea; Fiji Ids. ; Kandavu Reef.
( Mauritius; Java; Sandwich Ids;
( Fiji Ids.; New Caledonia.

( Zanzibar; RedSea; E.Indialds.;
< Japan; Sandwich Ids.; Fiji
( Ids.; Philippines; Kandavu.
West Coast of Africa.
Sandwich Islands; Philippine

Islands ; Seychelle Islands.
Senegal; Cape Verde; Brazil;
W. India Islands ; Bermudas ;
Ascension.
Peru ; Panama ; Gulf of Cali-
fornia.
Florida ; Hayti.

Kingsmills Islands ; Bonin
Islands ; Zanzibar ; New
Caledonia ; Fiji Islands.

Mauritius ; Java ; Samoa.

( Patagonia ; ChUi ; Peru ;
( Philippines.
Australia.
Japan.

North European ; North Pacific ;

North East Coast of America.

Australia ; Tasmania ; Samoa ;

New Caledonia ; New South

Wales.

Tertiary.

Pliocene.
'North America.

t Nummrdite ;
< Miocene.
( India ; Java.

Miocene ; Plio-
cene.
"North America;
Sweden; Java.

Cretaceous

Jurassic.

212

THE VOYAGE OF H.M.S. CHALLENGER.

Range

in Depth.

Priucipal Localities.

Tertiary.

Ci-etaceous.

Jurassic.

Fathoms.

Strongylocentrotus — continued.

S. frandscanxis, A. Ag.

—

( Formosa ; Puget Sound ; San
\ Diego ; Japan.

S. gaiimirdi, A. Ag.

—

BrazU.

X (S. gibbosus, A. Ag.
S. intermedins, A. Ag.

-45 C.

(Chili; Galapagos; Peru; Fiji
( Islands ; West Patagonia.
Japan ; Australia.

Miocene ; Plio-

S. lividus, Br.

iS'. mexicanus, A. Ag.

—

( European Atlantic ; Mediter-
( raneau ; Azores ; Brazil.
Gulf of California.

cene.
"North America;
Sweden; Java.

S. nudus, A. Ag.

—

Sandwicli Islands ; Japan.

;S. ptirpuratus, A. Ag.

—

San Fi-ancisco ; Puget Sound.

S. tubercwlatiis, Br.

—

( Japan ; China ; Australia ; New
I Zealand ; Galapagos.

.

Sphccrechinus, Des.

-,

X S. australice, A. Ag.

-40 C.

( Australia ; Mauritius ; New
( Zealand ; New South Wales.

Pliocene.
' Italy ; Austria.

X S. granulans, A. Ag.

-400 C.

( Mediterranean ; Canary Islands ;
< West Coast France ; Azores ;

( St Vincent.

S. pidcherrimus, A. Ag.

—

Japan ; China Seas.

.

Pseudoboletia, Trosoh.

P. graniilata, A. Ag.

—

Sandwich Islands.

X p. Indiana, A. Ag.

-IOC.

Philippine Islands ; Maui-itius.

Echinostrephus, A. Ag.

C Society Islands ; Zanzibar ;

E. molare, A. Ag.

~

< Natal ; Sandwich Islands ;
( East India Islands.

EcHiNiD^, Agass.

TEiiNorLEURiDyE, Des.

Temnopileuncs, Agass.

-1

X T. hardwkkii, A. Ag.

-129 C.

/ Japan ; Kamtchatka ; Philip-

\ pines ; Arafura Sea.

i Ceylon ; China Seas ; East

Eocene ; Mio-

X T. reynaudi, Agass.

-275 C.

< India Islands ; Philippines ;
( New Zealand.

cene.
"India; Java;
Egypt.

( Bombay ; East India Islands ;
I China; Gulf of Persia;
( Philippines.

X T. torcumciticus, Agass.

-20 C.

.

Pleurechinus, Agass.

X P. bothryoides, Agass.

—

^(Galapagos?); Japan ; Arafura
j Sea.

TemnecUinus, Forbes.

Crag.

-Australia ;
India.

\

T. maculatus, A. Ag.

30-600 B. J.

( Straits of Florida ; Azores ;
< Josephine Bank ; Caribbean
( Islands.

> Cretaceous.

*Prionechinus, A. Ag.

*P. sagittiger, A. Ag.

700-1070 C.

Philippines ; New South Wales.

CottahUa, Des.
*C. forbesiana, A. Ag.

310-315 C.

Fiji Islands.

( Eocene ;
( Miocene.

1 Chalk.

Microcyplms, Agass.

M. macnlat-m, Agass.

—

( Japan ; Navigator Islands ; East
) India Islands.

X M. zigzag, Agass.

-40 C.

(Japan; Philippine Islands;
( Tasmania ; New South Wales.

REPORT ON THE ECHINOIDEA.

213

Trigonocidaris, A. Ag.
T. albida, A. Ag.
■■•T. monolini, A. Ag.

Salmacis, Agass.
X ,?. hicolor, Agass.

X S. dussumieri, Agass.
X S. globator, Agass.
X & rarispina, Agass.

X S. sulcata, Agass.

Mespilia, Des.
X M. rjlohulus, Agass.

Amhlypneustes, Agass.

X A. formosiis, Val.
A. (jriseus, Agass.
A. ovum, Agass.
A. pallidus, Val.
A. pentagonus, A. Ag.

Holopneustes, Agass.

H. inflatus, A. Ag.
H. porosissimus, Agass.
X H. purpurescens, A. Ag.

Thiplechinid^, a. Ag.

Phymosoma, Haime.
P. crenulare, A. Ag.

Hemipedina, Wright.
H. cubensis, A. Ag.

Echinus, Rond. (Linn.)

X E. acidus, Lamk.

E. albocinctus, Hutt.
X E. angulosus, A. Ag.
E. darkyensis, Wood.

X E. clcgans, Diib. o. Kor.

E. elevatus, Hutt.
E. esculentus, Linn.

E. gracilis, A. Ag.
■'•E. horridiis, A. Al;.

Range
in Depth.
Fathoms.

60-450 B.
[520 C.

-10 0.

-100 C.
-8 0.
-28 0.

-10 0.

-40 C.

-15 C.

138-270 B.

-1350 0.

-20 0.

80-1350 0.

93-200 B.
[175 0.

Principal Localities.

Tertiary.

Straits of Florida; Caribbean

Islands ; Josephine Bank.
Kermadec Islands.

iRed Sea ; Mozambique ; Bom-
bay; Philippines.
China Seas ; East India Islands
Philippines.
Australia ; Arafura Sea.

{Philippine Islands ; Siam ;
China Seas ; Arafura Sea.
(Australia; Philippine Islands;
\ Mozambique ; Red Sea.

( Japan ; Philippine Islands ;
\ Sandwich Islands.

Australia ; New South Wales.

Australia ; New Zealand.

Australia.

Australia; Fiji Islands.

Mauritius (l).

Australia.
Australia.
Australia ; New South Wales.

Japan.

Straits of Florida.

C Norway ; Shetland Islands ;
J Mediterranean ; Ascension ;
1 Halifax to New York ; Ker-
l madec Islands.
New Zealand.

Cape of Good Hope ; Mauritius ;
Red Sea; Philippines; New
Zealand ; Australia.
Aiistralia.

Norway; off Valencia; Medi-
terranean; Halifax to New
York ; Tristan da Cunha ;
1^ Papua.
New Zealand. I

Norway ; English Channel. '
Straits of Florida; West India

Islands.
Straits of Magellan ; West
Patagonia.

Australian
(> (Paradox-
echinus).

Eocene ; Plio-
cene.
Italy.

Eocene.

Swiss; Italian
{Leiopedina
chrysomelon).

Eocene
{Lciopedina).

Eocene.

North America.

Eocene ; Mio-
cene ; Plio-
cene.

England (Crag);

France ; Malta ;

Austria ; India ;

North America.

Cretaceous.

Jurassic.

Lower Chalk.

Lower Chalk.

Jura.

Cretaceous.

214

THE VOYAGE OF H.M.S. CHALLENGER.

Eange

in Depth.

Priucipal Localities.

Tertiary.

Cretaceous.

Jurassic.

Fathoms.

Echimis — continiied.

r Patagonia ; Cliili ; New Zealand ;

■>,

X E. magdlanicus, Pliil.

-1600 C.

J Australia ; Cape of Good
Hope to Marion Island to
Kerguelen ; Falkland Islands.

TWest Patagonia; Straits Mag-

X E. margaritaceus, Lamk.

-245 C.

< ellan ; New Zealand ; Ker-
( guelen ; Heard Island.

Eocene ; Mio-
cene ; Plio-

( Mediterranean ; Canaries ; Cape

cene.

y Cretaceous.

E. melo, Lamk.

-190.

\ Verde Islands.

-England (Crag);

E. microstoma, W. Th.

150-450 P.

West Coast Scotland and Ireland.

France; Malta;

E. microtubercidatus, Bl.

Mediterranean ; Cape Verde Ids.

Austria; India;

J

E. miliaris, MiiU.

—

Norway ; English Channel.
'Norway ; off Valencia ; Mediter-
, ranean ; Straits of Florida ;
] Atlantic Coast of U. S. ;
[ Japan ; West Patagonia.

North America.

X E. norveyims, Diib. o. Kor.

80-2435 B. P.

E. wallisi, A. Ag.

257-1047 B.

"Atlantic Coast of U. S.
(Southern and Middle States).

J

Toxopneustes, Agass.

■

T. maculatus, A. Ag.

—

Christmas Island ; Bourbon.

f Panama ; East India Islands ;
J Fiji Islands; Mauritius;

X T. pileolus, Agass.

-10 C.

New Caledonia; Sandwich
Lslands ; Philippines.

North America
(West Indian).

T. semihiberculatus, Ag.

—

(■ Galapagos ; AVest Coast Central
1 America ; Cape St Lucas.

I Bermudas ; South Carolina ;

X T. variegatus, A. Ag.

-300 B.

< West India Islands; Brazil;
( Straits of Florida.

Hipponoe, Gray.

H. dcpressa, A. Ag.

—

Gulf of California.
( Florida ; Yucatan ; West Indies ;

H. esculenta, A. Ag.

-451 B.

] Surinam; Bermudas;

f Sandwich Islands ; Japan ; East

1 India Islands; Fiji Islands;

Miocene.
France.

X H. variegata, A. Ag.

-15 C.

■I Red Sea ; Mozambique ;
1 Philippines ; Kandavu Reef ;

(^ New South Wales.

J

EvecUnus, Verrill.

X E. chloroticus, VerrilL

—

New Zealand ; Kandavu Reef.

CLYPEASTRID^, Agass.

EcHiNOCONiD^E, d'Orb.

Pygaster, Agass.

P. relictus, Lov.

[180 J.

West India Islands.

Cretaceous.

Jura.

Edclypeastrid^, Hfeck.

FiBULARlNA, Gray.

Echinocyamus, Van Phelps.

( Norway ; Iceland ; Mediter-

Miocene.

Swit7prlnTid ■

Upper Chalk.

X E. pusilliis, Gray.

-805 B.

} ranean; Azores; Florida;

A T1 Clfl'Tl •

|- France ; Bel-

( Caribbean Ids. ; North Brazil.

.cLuuiiiaj

France.

gium ; Sicily.

REPORT ON THE ECHINOIDEA.

215

Fihdaria, Lamk.
X F. australis, Desml.

F. omdum, Lamk.
X F. volva, Agass.

ECHINANTHIDiE, A. Ag.

Clypeaster, Lamk.
X C, humilis, A. Ag.

C. rotundus, A. Ag.
X G. scutiformis, Lamk.

X G. subedepressus, Agas.s.

Echiimnthus, Breyn.
E. rosaceus, Gray.

X E. testud.inarius, Gray.

Laganid^, Des. (Emend.)

Laganum, KL
L. bonani, KL

X L. depresstim, Less.
X L. putnami, Bam.

Peronella, Gray.

X P. decagonalia, A. Ag.

P. orbicidaris, A. Ag.
X P. peronii, Gray.
P. rostrata, A. Ag.

ScUTELLIDiE, Agass.

Echinarachnius, Leske.
E. exceyitricus, VaL
E. mirabilis, A. Ag.

Ringe
in Depth.
Fathoms.

Principal Localities

-950 C.

-28 C.

-20 C.

-120 B.

-118 B.
-120 C.

-25 0.

-315 C.

-40 C.

i Sandwich Lslands ; Japan ; Aus-

< tralia ; Kingsmills Islands ;

( New South Wales.

( Indian Ocean ; Philippine

/ Islands.

( Red Sea; Formosa; North

) Australia.

Red Sea; East India Islands;

New Oaledonia ; Philippines ;

Amboyna.
Panama ; San Diego.
Red Sea; Philippine Islands;

Kingsmills Islands; Japan;

New Caledonia.
AVe=t Coast of Africa; Sotitli

Carolina ; Florida ; Brazil ;

West India Islands.

( West India Islands; Florida;
( South Carolina.
I Australia ; Japan ; Sandwich
< Islands ; Gulf of California ;
( New Soul h Wales.

Tasmania ; East India Islands ;

Philippine Islands.
'Kingsmills Islands; Fiji
Islands ; Philippine Islands ;
Australia ; Zanzibar ; Arafura
, Sea.
Japan ; Amboyna.

Japan ; New Caledonia ; Bay

of Bengal ; East India

Islands ; Tahiti ; PhUip-

[ pines ; Tonga ; Arafura Sea.

Australia ; Formosa.
( Tasmania; Philippine Islands;
( New South Wales.
New Zealand ; Zanzibar.

Oalifoniia ; Alaska ; Kamt-

chatka.
Japan ; Aleutian Islands.

Tertiary.

Eocene.
Italy.

Eocene ; Mio-
cene; Pliocene.

North America;
West Indies ;
Italy; Corsica;
Egypt ; Java.

f Eocene ; Mio-
cene; Pliocene.
Austria ; Cor-
sica ; Malta ;
Caucasus;
India ; Java ;

t Australia.

Eocene ; Mio-
cene ; Pliocene.
"Java; North
America ;
EgJ'pt-

I North America;
Patagonia ;
Australia.

Cretaceous.

Jiu'assic.

{Danien.
Belgium.

216

THE VOYAGE OF H.M.S. CHALLENGER.

Ecliinarachnius — continued.

E. paniui, Gray.

Arachnoides, Kl.

A. placenta, Agass.

Echinodiscns, Breyn.
E. auritus, Leske.
E. Uforis, A. Ag.

X E. Imvis, A. Ag.

MelUta, Kl.

M. erythrcea, Gray.
M. longifissa, Mich.
M. pacified, Verrill.

X M. sexforis, A. Ag.
M. stokesii, A. Ag.

M. testudinata, Kl.

Astriclypeus, Verrill.
xA. manni, Verrill.

Rotula, Kl.

R. augusti, Kl.
R. rumj)hii, Kl.

Eneope, Agass.

E. californica, Verrill.

X E. emanjinata, A ass.

E. (jrandis, Agass.
E. michelini, Agass.
E. micropora, Agass.

PETALOSTICHA, Haeckel.
CassiddlidjE, Agass.

EcHlNONElD.*;, Agass.
Echinonciis, Van Phel.

E. cyclostomus, Leske.

E. semilunaris, Lamk.

NUCLEOLID.E, Agass.
Ncolampas, A. Ag.
N. rostellata, A. Ag.

Range
in Depth.
Fathoms.

-306 B.

-270 B.

B.

-70 C.
-11 B.

Principal Localities.

fNew Jersey; Labrador; off
George's IJank, Vancouver
Island ; Kamtchatka ; Aleu-
tian Islands ; Japan ; Aus-

[ tralia ; India ; Red Sea.

j New Zealand ; Australia ;
( East India Islands ; Burmali.

Zanzibar; Philippine Islands.
( Mozambique ; Red Sea ; Java ;
( Cape of Good Hope.
( Japan ; New Caledonia ; East
) India Islands ; South Africa.

Red Sea (?).

Panama ; GuK of California.

Peru.

"West India Islands; South
Carolina ; Bermudas ; Brazil.

Guayaquil ; Panama ; Gala-
\ pagos.

( Brazil ; West India Islands ;
) North and South Carolina;
( Nantucket.

China; Japan.

Liberia.

Senegal ; Cape Verde Islands.

Gulf of California.
( Brazil ; West Indies ; Yuca-
} tan ; Florida ; South Caro-
( lina.

Gulf of California.

Yucatan ; Florida.

Panama ; Gulf of California,

Tertiary.

Cretaceous.

Jurassic.

100-690 B. P.;

Australia ; Kingsmills Islands ;
Zanzibar ; East India Islands.
Florida ; West India Islands.

Straits of Florida; Caribbean
Islands ; North-East Atlantic.

North America;
Patagonia ;
Australia.

^ Miocene.
I California (As-
I terodaspis ?)
I Australia.

-France; Austria.

Pleistocene.
"North America.

Pleistocene.
"North America.

Miocene.
I North America;
West Indies.

REPORT ON THE ECHINOIDEA.

•217

Range

in Depth.

Principal Localities.

Tertiary.

Cretaceous.

Jurassic.

Fathoms.

Echinolampas, Gray.

European;

E. akxandri, Lor.

—

Mauritius.

Switzerland;

E. depressa, Gray.

-160 B.

( Straits of Florida ; Caribbean
( Islands.

Austria; Italy;
India ; Java ;
Australia;

E. hellei, Val.

—

Senegal.

I Red Sea; Molucca; Cape of

Cuba; North

X E. oviformis, Gray.

-129 C.

< Good Hope ; Mauritius ;
( Indian Archipelago.

America;
West Indies.

' Eocene ; Mio-
cene.

^

Oonochjpus, Agass.
C. sigshei, A. Ag.

84-450 B.

Straits of Florida ; Yucatan.

Austria;
• Switzerland;

Italy ; Corsica ;

Crimea; India;
!^ West Indies.

Upper Chalk.
"France.

Catopygus, Agass.
'.=0. recens, A. Ag.

[129 C.

Indian Arcliipelago.

( Australia; West
( Indies.

r U p p e r,
J Middle, and
Lower Chalk.
^ Europe ;India.

1

PJiynchojjyrjus, D'Orb.
ii. caribbmarum, Liitk.

-106 B.

West India Islands.

'Australia; Crag;
Switzerland ;
1 Cuba ; West
Indies.

iJ. pacijicus, A. Ag.

j Galapagos; Panama; Gulf of
( California.

-Gault, India.

Eu/ij'h obrissus, Breyn.
J7. recens, D'Orlj.

—

New Zealand ; Madagascar.

Australia.
'Eocene; Mio-

Cretaceous.

j Middle and
( Upper Jura.

Nudeolites, Lamk.
N. epigonus, Mart.

—

East India Islands.

cene.
Switzerland ;
North America;
AVest Indies ;

Anochanus, Grube.

, Java.

A. sinensis, Grube.

—

East India Islands.

SPATANGIDyE, AgaSS.

POUKTALESI^, A. Ag.

Pourtalesia, A. Ag.

1

■••P. carinata, A. Ag.

1950-2225 C.

^ Heard Island to Antarctic ; Juan

( Fernandez to Chili.

I Antarctic ; Heard Islands to

■fP. ceratopyrja, A. Ag.

1950-2225 C.

< Australia ; Juan Fernandez
( to Chili.

■••P. hispida, A. Ag.

1600-1975 C.

Marion Island to Australia.

P. jeffreysi, Wy. Th.

[690 P.

Faroe to Shetland Islands.

Crag

\

( Japan to Sandwich Islands ;

- (JEchinarachnius

\ Infidastcr.

■fP. hiyuncula, A. Ag.

345-2900 C.

} Japan ; Arafura Sea ; New
( Zealand.

woodii) (?).

i

P. miranda, A. Ag.

242-1215 B. P.

( Straits of Florida ; Shetland
1 Channel ; Caribbean Islands.

X P. phiale, Wy. Thorn.

S 1215-1975
1 P. C. Val.

] Kerguelen to Australia ; North
( Atlantic ; Rockall.

■■'P. rosea, A. Ag.

[2600 C.

\ Sandwich Islands to Low Archi-
l pelago.

*Spatagocystis, A. Ag.

■fS. challengeri, A. Ag.

1600-1950 C.

( Marion Island to Kerguelen,
\ Australia.

(ZOOL. CHALL. EXP. PART IX. 1881.)

I 28

218

THE VOYAGE OF H.M.S. CHALLENGER.

Range
in Depth.
Fathoms.

*Echinocrepis, A. Ag.
*E. cmieata, A. Ag.

*UreMnn,s, A. Ag.

*f7. naresiaiius, A. Ag

*Gijsteehmus, A. Ag.
*C dypeatus, A. Ag.

*C'. vesica, A. Ag.

*C. mj villa, A. Ag.

*Galymnc, Wy. Thorn.
*a reZicia, Wy. Thorn.

ANANCHYTID.E, Alb. Gras.

Pal(cotro])us, Lov.
P. josephince, Lov.
*P. lovhii, A. Ag.
P. thomsoni, A. Ag.

*Argopatagus, A. Ag.
*^. vitreus, A. Ag.

*Genicopata(jus, A. Ag.
*e. n#?!Js, A. Ag.

Homolampas, A. Ag.
X IT. frayilis, A. Ag.

*i/. /(tfea, A. Ag.

Pcdcopneustes, A. Ag.
P. cristatus, A. Ag.
P. hystrix, A. Ag.

"Linopneustes, A. Ag.
*i. murrayi, A. Ag.
i. longispinus, A. Ag.

Platyhrissus, Griibe.
P. rwmeri, Grube.

Spatanoina, Gray.

Spatangus, Kl.

S. liitkeni, A. Ag.

X S. purpureus, Leske.

X S. raschi, Lov.

[1600 C.

1200-1800
B.C.

1050-19150.

1675-2225C.
1375-1825 C.

620-2650 C.

82-250 B.J.
[375 C.
[23.3 B.

[800 C.
[1950 C.

300-1920 B.
2425-2475 C.

56-450 B.
21-208 B.

345-375 C.
28-298 B.

-450 B. C.
150-300 P.O.

Principal Localities.

Marion Island to Kerguelen.

{Marion Island to Kerguelen to
Australia ; Juan Fernandez
to Straits of Magellan; Carib-
bean Islands.

( Philippines ; Tristan da Cunha

< to Bahia; Tristan da Cunha
( to Buenos Ayres.

( Antarctic to Kerguelen to Aus-

< tralia; Juan Fernandez to
( Chili.

Marion Island to Kerguelen to
Australia; Juan Fernandez
to Chili.

Azores.

Caribljean Islands; Azores.

Philippines.

Atlantic Coast ol U. S. (So. Ca.).

Arafura Sea.

Antarctic ; Kerguelen to Aus-
tralia.

Straits of Florida; North
Brazil ; Josepliine Bank.

Sandwich Islands to Low Archi-
pelago.

Straits of Florida ; Caribbeanlsds
Caribbean Islands.

Philippines; Japan.
Caribbean Islands.

Japan.

Norway ,' Shetland Islands ;

Mediterranean ; Caribbean

Islands ; Bermudas ; Azores.
German Ocean ; Azores ; off

Valencia; Shetland Islands;

Cape of Good Hope.

Tertiary.

\ North America
) (Holaster, sp.}.

Italy.

/ Eocene.
Italy.

Cretaceous.

Jurassic.

Eocene ; Mio-
cene ; Plio-
cene.
England; West-
phalia; Switz-
erland; Italy;
Palermo; Mo-
rea.

REPORT ON THE ECHINOIDEA.

219

Mardia, Gray.

X M. alta, A. Ag.
M. elliptica, Bol.

X M. plamdata, Gray.

Nacopatagtis, A. Ag.
N. gracilis, A. Ag

Eupatagus, Agass.
X E. valenciennesii, Agass.

Lovenia, Des.

L. cordiformis, Liitk.

X L. elongata, Gray.
X L. Buhcarinata, Gray.

Breynia, Des.
xB. australasia, Gray.

Echinocardium, Gray.
X E. cmstrale, Gray.

Range
in Depth.
Fathoms.

E. cordatum, Gray.

-85 B.

X E. flavescens, A. Ag.

-150 B.

E. mediterranev/in. Gray.

—

E. pennatifdum, Norm.

79-121 B

Leskiad^, Gray.

Paleostmia, Loven.

P. mirabilis, Loven.

—

-800 C.

-25 C.

[65 B.

-28 C.
-IOC.

Principal Localities.

-2675 C.

Japan ; Luzon ; Arafiira Sea.
South Sea.
' Kingsmills Islands ; China ;
East Inilia Islands; New
Caledonia; Mam-itins; Aus-
^ tralia; Levuka Reef.

Juan Fernandez.

j Australia ; Arafura Sea ; New
( South Wales.

Guyaquil ; Gulf of California.

Red Sea; Au.stralia ; Philip-
pines ; Arafura Sea ; Cape
of Good Hope.

Cliina ; Luzon ; Japan ; Sand-
wich Islands.

Red Sea ; Australia ; Japan ;
Sandwich Islands ; Torres
Straits.

f New Zealand ; Australia ; New
J Soutli Wales ; Tasmania;
Japan ; East India ; Cape
of Good Hope ; Mozambique.
Norway; Shetlands; Mediter-
ranean; Brazil; Florida;
North Carolina.
Norway ; Shetland Islands ;
Cape of Good Hope ; South
Carolina ; Florida.
Mediterranean.
J Northumberland; Shetland
( Islands ; Straits of Florida.

China ; East India Islands.

Tertiary.

Eocene ; Mio-
cene ; Plio-
cene.
'France; Italy;
India; Java;
Australia.

f Eocene ; Mio-
cene ; Plio-
cene.
Australia;
India ;Egypt;
Malta ; Italy ;
Switzerland ;
France ; West
Indies.

Crimea ; Cor-
sica ; Java ;
Australia.

f Eocene ;

j cene.

<5 France;

Java ;

Cuba.

Mio-

Italy;
India ;

Cretaceous.

Mio-
Plio-

Eocene

cene

cene.
North America;

England ;

Italy; India;

Switzerland.

Jurassic.

220

THE VOYAGE OF H.M.S. CHALLENGER.

Brissina, Gray.
Hemiaster, Des.
X H. cavernosus, A. Ag.

H. experr/itus, Lov.

■'■H. yihbosus, A. Ag.

■••H. zonatus, A. Ag.

H. mentzi, A. Ag.

Tripylus, Pliil.

T. excavatus, PliiL

Ehinobrissus, A. Ag.

*i?. hemiasteroides, A. Ag.
iJ. micmsferoides, A. Ag.
iv. pyrainidalis, A. Ag.

*Cionobrissus, A. Ag.
*C revincttts, A. Ag.

Brissopsis, Agass.
X -B. luzonica, A. Ag.

X B. lijrifcra, Agass.

*Aerope, Wy. Thorn.

•.=vl. rostrata. Wy. Tliom.

%Aceste, Wy. Thoin.

*v4. hdlidifera, Wy. Thorn.

*^3asstzia, Val.

.4. cKceninca, A. Ag.

.4. scrobiculata, Val.

Brissus, Kl.

B. carinaius, Gray.

*i?. damcsi, A. Ag.
i?. obcsus, Verrill.

jB. unicolor, Kl.

Kange in

Depth.

Fathoms.

-400 C.

464-485 B.J,

345-800 C.
620-750 C.
170-576 B.

[20 C.
175-242 B.

[800 C.

-1100 C.
-2435 P.

800-1750
C. Val.

[2600 C.

36-391 B.

120-450 C.
-7B.

Pi'iucipal Localities.

Patagonia ; Chili ; La Plata
River ; Straits of Magellan ;
Kerguelen ; Heard Islands.

Caribbean Islands ; East At-
lantic ; West Coast of Spain,
lat. 38 N., long. 0-9 W.

Japan ; Arafura Sea.

Bahia; Canary Islands.

Caribbean Islands.

Patagonia; Chili.

Tahiti.

Caribbean Islands
China.

Arafura Sea.

Luzon ; Siam ; New Caledonia ;
Tahiti ; NewZealand ; Philip-
pines ; Japan ; Arafura Sea.

Norway ; Mediterranean ; Flo-
rida ; Greenland ; Cape Good
Hope; Caribbean Islands.

Arafura Sea ; Bay of Biscay ;
Davis Straits.

( Sandwich Islands to Low Archi-
< pelago; Buenos Ayres to Tris-
( tan da Cunha ; Canary Isd.s.

Florida Gulf Stream ; Caribbean
Islands,

Pent; Panama; Gulf of Cali-
fornia.

Society Islands ; Sandwich
Islands ; East Indies ; Mauri-
tius; Philippine Islands.

North Brazil ; Azores.

Panama ; Gulf of California.

AVest India Islands; Cape
Verde Islands ; Mediterra-

Tertiavy.

Cuba ; North
America;
Europe;
Malta;Iudia;
Java.

I Australia

r {Micraster, sp.).

England (Crag).

France ; Swit-
zerland; Italy;
India ; North
America ;West
Indies.

f Eocene ; Mio-
cene.
■{ North America;
West Indies ;
Egypt.

Eocene ; Mio-
cene ; Plio-
cene.

North America;
West Indies;
Pyrenees;
Malta; Italy;
England;
Java.

Cretaceous.

Jurassic.

1

I Upper Chalk.
y India ;
Europe.

REPORT ON THE ECHINOIDEA.

•221

Range in
Dejith.

F;itli()iiis.

Principal Localities.

Tertiary.

Cretaceous.

Jiiras.sic.

Metalia, Gray.

1

M. africana, A. Ag.
M. costal, Lud.

X M. maculosa, A. Ag.
X M. pectoralis, A. Ag.

-25
-28 C.

-15C B.

Sherboro Islands.
Mediterranean ; Capri.
'Samoa; Sandwich Islands; Aus-
J tralia ; Mauritiu.s ; Panama ;
1 Gulf of California ; Arafura

Sea.
S West India Islands; Florida;
1 Brazil.

1

North America;

- West Indies ;

Malta ; Italy.

M. sternalis. Gray.

~~

■ Sandwich Islands ; Society ;
J Islands ; East India Islands ;
Philippine Islands ; Australia;
New Caledonia ; Red Sea.

J

Meoma, Gray.

^

M. grandis. Gray.
M. ventricosa, Liitk.

-242 B.

Acapulco ; Gulf of California.
^ West India Islands ; Straits of
( Florida.

Australia;
- Culia ; West
Indies.

Linthia, Mer.

L. australis, A. Ag.
L. rostrata. Smith.

—

Tasmania.
Pacitic Islands.

■J Eocene ; Mio-

> cene.

) India ; Europe.

) Middle and
( UpperChalk.

Faorina, Gray.

F. chinensis, Gray.

—

China ; Sandwich Islands.

Schizaster, Agass.

^

S. canalifenis, Agass.

X S. fraijilis, Agass.

S. (jihberulus, Agass.
■fS. japoniciis, A. Ag.

•fS. moseleyi, A. Ag.

S. philipini, A. Ag.
X S. ventricosus, Gray.
S. orbignyanus, A. Ag.

-37
71-955 B.

8-5U C.
40-1375 C.

-345 C.
92-1507 B.

Mediterranean.

' Norway ; Gulf St Lawrence ;
Gulf of Maine ; East Coast of
U.S. Atlantic (middle States) ;
Straits of Florida; Caribbean
Islands ; Cape of Good Hope.
Red Sea.

Off Japan ; China ; Arafura Sea.
( Marion Island ; Kerguelen ;
} West Patagonia; Straits of
( Magellan.

Patagonia.
( Fiji Islands ; Philippines ;
( Siam ; Japan.
Caribbean Islands.

Eocene.

England;
France ; Swit-
zerland ; Aus-
tria ; Italy ;
- Malta; India;
Java ; Aus-
tralia ; N(jrth
America;
Cuba ; West
Indies.

J

Pcriaster, D'Orb.
X P. Kmicola, A. Ag.

28-118 B.C.

Gulf of Me.Kico ; Arafura Sea.

' Eocene.

J Europe; Egypt;
India ; Java ;

f Chalk.
J Egypt ;
< r ranee ;

West Indies.

North
[ America.

*Moiropsis, A. Ag.

■M claudicans, A. Ag.

[129 C.

Indian Archipelago.

Moira, A. Ag.

M. atropos, A. Ag.

AT. cZoi/io, A. Ag.
M. stygia, A. Ag.

-60 B.

( West Indies ; North and South
j Carolina ; Straits of Florida.

Gulf of California.

Red Sea (?); Zanzibar (?).

^West Indies.

222 THE VOYAGE OF H.M.S. CHALLENGER.

We may for the present, for the purpose of showing the extent of the bathymetrical
range, subdivide the preceding table into three groups, which I will call the Littoral, the
Continental, and the Oceanic or Abyssal.

The divisions into littoral, continental and abyssal or oceanic are not arbitrary ; they
represent in the present state of our knowledge of the depths of the oceans, bathymetrical
lines of great physical importance. The littoral fauna extends over that shallow area
of the shores which is merely the extension under water of the shores themselves (to 100
or 150 fathoms) ; the continental line represents the extent to which we may fairly
assume that the lines of continents have been modified, the limits within which probably
subsidence and elevation as affecting continental masses, or rather their shores, have
taken place, to 450 or 500 fathoms, while the third region beyond this, that which has
been called abyssal or oceanic, undoubtedly represents those large areas of the ocean floor
which have remained unaffected through long geological periods. This view is gradually
gaining ground among geologists, and was one of the very first results arrived at by the
late Professor Agassiz in his discussions of the results of the dredgings of Mr Pourtales in
1866 and 1867. He had previously followed Guyot^ and Dana^ and come to the con-
clusions that the present continental areas, or at least their skeletons, are of very ancient
origin, and that the great oceanic basin had remained practically undisturbed from the
earliest geological periods.'' It may not be out of place to repeat here a part of Professor
Agassiz's argument : — " From what I have seen of the deep-sea bottom I am already led
to infer that among the rocks forming the bulk of the stratified crust of our globe, from
the oldest to the youngest formation, there are probably none which have been formed in
very deep waters. If this be so, we shall have to admit that the areas now respectively
occupied by our continents as circumscribed by the two hundred fathom curve or there-
about, and the oceans at greater depth, have from the beginning retained their relative
outline and position ; the continents having at all times been areas of gradual upheaval
with comparatively slight oscillations of rise and subsidence, and the oceans at all times
areas of gradual depression with equally slight oscillations." The same view has been
adopted by Geikie.*

This was practically the same view developed by Thomson in the Depths of the Sea,
and previously in a lecture delivered before the Royal Institution in April 1869, and the
subject was greatly advanced by the analysis made by Mr Murray' of the nature of the
deposits on the ocean bottoms as contrasted to those which constitute the crust of the
globe. Dr Carpenter " has also further developed this view of the great antiquity of the
oceanic basins.

1 Earth and Man, 1856.

2 J. D. Dana, Manual of Geology, 1863, p. 732 ; Proc. Am. Ass. Adv. Science for 1873 ; Am. Journ. of Science, 1873.

3 L. Agassiz, Nov. 1869, Bull. Mus. Comp. Zool., vol. i.. No. 13. * Geograpliical Evolution, 1879.
^ John Murray, 1876, On Oceanic Deposits, Proc. Roy. Soc, No. 170.

8 W. B. Carpenter, 1880, Lecture before the Royal Institution, January 23, 1880.

REPORT ON THE ECHINOIDEA.

223

Littoral Species.

DESMOSTICHA., Ha;ckeL

CiDARlDiE, Miiller.

GoNiociDAEiDiB, Hacckel.

Cidaris, Kl.

C. metularia, Bl., .

C. thouarsii, Val., .
X G. tribuloides, BL, .

Dorocidaris, A. Ag.
■\'D. bmcteata, A. Ag.,

X D. papillata, A. Ag.,

Phyllacanthiis, Br.
X P. annulifera, A. Ag.,
X P. baculosa, A. Ag.,

P. duhia, Br.,
X P. (jigantea, A. Ag.,

P. imperialis, Br., .

X P. verticillata, A. Ag.,

Stephanocidaris, A. Ag.
S. bispinosa, A. Ag.,

Goniocidaris, Des.

X G. caiialiculata, A. Ag.,

O. geranioides, Agasa.,
X G. tid)aria, Liitk., .

ARBACiADiE, Gray.

Arbacin, Gray.

A. auatralis, Tro-sch.,
xA. dufresnii, Gray,
X A. nigra, A. Ag., .

A. punctulata, Gray,
X A. pustulosa, Gray,

A. spatuligcra, A. Ag.,

A. stdlata, Gray, .

DiADEMATiDiE, Peters.

Diadema, Schynv.,

D. mexicanum, A. Ag., .

X D. setosum, Gray, .

Centrostephanus, Pet.
G. coronatus, A. Ag.,
C. longispinus, Pet.,
G. rodgersii, A. Ag.,

Range
in Depth.
Fathoms.

-250 B.

15-100 C.
-874 B.

-28 C.
-102 C.

-8C.

-1975 C.
-40 C.

-175 C.
-125 B.

-115 B.

Principal Localities.

Cape of Good Hope; Red Sea; Mauritius; East India

Islands; Sandwich Islands ; Fiji Islands.
Panama ; Gulf of California.
South Carolina ; Florida ; Brazil ; Cape Palmas.

Amboyna.
( Shetland Islands ; Norway ; Jlediterranean ; Canary
•; Islands; Florida; Caribbean Islands; St Paul's Rocks;
( La Plata ; Philippines.

Australia; Philippine Islands; Torres Straits.

Red Sea ; Zanzibar ; Mauritius ; Philippines.

Zanzibar; Bonin Islands; Austr.alia.

Sandwich Islands.

Red Sea ; East India Islands ; Australia.
^ Society Islands ; East India Islands; Australia; Sandwicli
( Islands ; Torres Straits.

Australia ; Malacca.

Falkland Islands ; Patagonia ; Natal ; Zanzibar; Marion Islands

to Kerguelen ; Heard Islands ; Kerguelen to Australia.
Australia ; East Indies ; Tasmania.
Australia ; Tasmania ; New South Wales.

Australia.

Patagonia ; Chili ; Nightingale Island.

Patagonia; Chili; Peru; Philippines.

Long Island Sound to West Florida ; Yucatan.

Mediterranean; Liberia; Brazil

Chili ; Peru.

Panama ; Gulf of California.

Acapulco ; Cape St Lucas.
( Bermudas; West India Islands
} Indian Ocean; Jajian
( Philippines.

_. Cape Verde Islands;

Sandwich Islands; Fiji Islands:

Cape St Lucas.
Palermo; Canary Islands.
Australia; New Caledonia.

224

THE VOYAGE OF H.M.S. CHALLENGER.

Range

in Depth.

Principal Iiocalities.

Fathoms.

Echinothrix, Pet.

X E. calamaris, A. Ag.,

—

( Society Islands ; East India Islands ; Philippine Islands ;
j Kandavu Reef.

E. desorii, Pet., ....

—

Red Sea; Fiji Islands; Sandwich Island.s.

X E. turcarum, Pet., ....

^ Sandwich Islands ; Fiji Islands ; Japan ; East India

j Islands; Red Sea; Zanzibar; Kandavu Reef.

Astropyrja, Gray.

A. clastica, Stud., ....

[20

New Britain.

xA. jndvinata, Agass., . .

-49 C.

Panama ; Gulf of California ; Torres Straits ; Honolulu.

A. radiata. Gray, ....

—

Zanzibar ; East India Islands ; Philippine Islands.

EcHiNOTHURlD^, Wy. Thom.

Asthenosomn, Grabe.

^•A. grubii, A. Ag., ....

[IOC.

Philippines.

A. varium, Grube.,

—

China Seas.

ECHINOMETRAD.E, Gray.

Colobocentrotus, Br.

C. atratiis, Br., .

—

Zanzibar ; Java ; Sandwich Islands.

C. mertcnsii, Br., ....

—

Bonin Islands ; Australia.

Heterocentrotus, Br.

X H. mammilkUics, Br.,

—

( Sandwich Islands ; East India Islands ; Red Sea ; Fiji
) Islands; Kandavu Reef.

X H. triijonarius, Br.,

—

j Maritius; Java; Sandwich Islands; Fiji Islands; New
( Caledonia.

Echinoraetra, Rondel. (Breyn.)

X E. lucunter, Bl., ....

-18 G

( Zanzibar ; Red Sea ; East India Islands ; Japan ; Sandwich
j Islands; Fiji Islands; Philippines; Kandavu Reef.

E. macrostoma, A. Ag., .

—

West Coast, Africa.

E. oblonga, Bl., ....

—

Sandwich Islands; Pliili ipine Islands; Seychelle Islands.

X E. suhawjularis, Desml.,

-250 B.

( Senegal; Cape Verde; Brazil; West India Islands; Ber-
( mudas ; Ascension.

E. van brunti, A. Ag., .

—

Peru ; Panama ; Gulf of California.

E. viridis, A. Ag., .

-7B.

Florida; Hayti.

Parasalenia, A. Ag.

P. gratiosa, A. Ag., . ,

—

S Kingsmills Islands; Bonin Islands; Zanzibar; Fiji
I Islands ; New Caledonia.

Stomopneustes, Agass.

S. variolaris, Agass.,

—

Mauritius ; Java ; Samoa.

Strongylocentrotus, Br.

S. albus, A. Ag., ....

—

Patagonia; Chili; Peru; Philippines.

S. armiger, A. Ag.,

—

Australia.

S. depressus, A. Ag.,

—

Japan.

X S. drobachiensis, A. Ag.,

-78

( North European; North Pacific; North-East Coast of
( America.

X S. eurythrogrammus, A. Ag., .

-35 C.

(Australia; Tasmania; Samoa; New Caledonia; New
I South Wales.

S. frandscamis, A. Ag., .

—

Formosa ; Puget Sound ; San Diego ; Japan.

S. gaimardi, A. Ag.,

—

Brazil.

X S. gibbosus, A. Ag.,

-45 C.

Chili; Galapagos; Peru; Fiji Islands; West Patagonia.

S. intermedius, A. Ag., .

—

Japan ; Australia.

, S. lividus, Br., ....

—

European Atlantic; Mediterranean; Azores.

S. mexicanus, A. Ag.,

—

Gulf of California.

S. niulus, A. Ag., ....

—

Sandwich Islands; Japan.

S. purpiirahis, A. Ag., .

—

San Francisco ; Puget Sound.

S. tuberculatus, Br.,

—

Japan ; China ; Australia ; New Zealand ; Galapagos.

REPORT ON THE ECHINOIDEA.

225

Spluerechinus, Des.
X S. australice, A. Ag.,
X S. granulans, A. Ag.,
S. jmlcherrimns, A. Ag.,

Pseudobohtia, Trosch.

P. granulata, A. Ag.,
X P. Indiana, A. Ag.,

Echinostrephus, A. Ag.
E. molare, A. Ag., .

EcHiNiDiE, Agass.

TEMNOPLEDEIDiE, DeS.

Temnopleurus, Agass.
X T. hardwickii, A. Ag., .
X T. reynandi, Agass.,

X T. toreumaticus, Agass., .

Pleurechinus, Agass.
X P. bothryoides, Agass., .

Microcyphus, Agass.

M. maculatus, Agass., .
X M. zigzag, Agass., .

Salmacis, Agass.

X S. bicolor, Agass., .
X S. dussumieri, Agass.,
X S. globator, Agass.,
X S. rarispina, Agass.,

X S. sulcata, Agass., .

Mespilia, Des.
X M. globulus, Agass.,

Amblypneustes, Agass.

X A. formosus, Val., .
A. griseus, Agass., .
A. ovum, Agass., .
A. pallidus, Val., .
A. pentagonus, A. Ag.,

Holopneustes, Agass.

H. infiatus, A. Ag.,
S. porosissimvs, Agass.,
X H. purpurescens, A. Ag.,

Triplechinid^, a. Ag
Phymosoma, Haime.
P. crenulare, A. Ag.,

Range
in Depth.
Fathoms.

-40 C.
-400 C.

-10 C.

-129 C.
-275 C.

-20 C.

-40 C

-IOC
-100 c

-8C
-28 C.

-10 C.

-40 C.

-15 C.

Principal Localities.

Australia ; Mauritius ; New Zealand ; New South AVales.
i Mediterranean ; Canary Islands ; West Coast, France ;
Azores ; St Vincent.
Japan ; China Seas.

Sandwich Islands.

Philippine Islands; Maiu'itius.

Society Islands; Zanzibar; Natal; Sandwich Islands;
East India Islands.

Japan ; Kamtchatka ; Philippines ; Arafura Sea.
( Ceylon ; China Seas ; East India Islands ; Philippines ;
\ New Zealand.

] Gulf of Persia ; Bombay ; East India Islands ; China ;
( Philippines.

Galapagos (1) ; Japan ; Arafura Sea.

Japan; Navigator Islands; East India Islands.

Japan; Philippine Islands; Tasmania; New South Wales.

Red Sea ; Mozambique ; Bombay ; Philippines.

China Seas ; East India Islands ; Philippines.

Australia ; Arafura Sea.

Philippine Islands; Siani; China Seas; Arafura Sea.
^ Australia ; Philippine Islands ; Mozambique ; Red
( Sea.

Japan; Philippine Islands; Sandwich Islands.

Australia ; New South Wales.

Australia ; New Zealand.

Australia.

Australia; Fiji Islands.

Mauritius (!).

Australia.
Australia.
Australia ; New South Wales.

Japan.

(ZOOL. CHALL. EXP. PART IX. — 1881.)

129

226

THE VOYAGE OF H.M.S. CHALLENGER.

Echinus, Eond. (Linn.).

X E. acjitus, Lanik.,

E. alhocindns, Hntt.,

xE. anyulosus, A. Ag.,

E. darleyensis, Wood.,
E. elevatus, Hutt., .
E. escuUntus, Linn.,

xE. mageUanicus, PliiL,

xE. margaritaceus, Lanik

E. melo, Lamk., .

E. microtuberculatus, Bl

E. .miliaris, MiilL,

Toxopneustes, Agasi?.
T. .niaculatus, A. Ag.,

X T. pileolus, Agass.,

T. semitiiherculatus, A.gass.,

X T. variegatus, A. Ag.,

Hip2}onoe, Gray.

H. de^ircssa, A. Ag.,
H. esculenta, A. Ag.,

X H. variegata, A. Ag.,

Evechinus, Veriill.
X E. Moroticus, VeirilL, .

CLYPEASTRIDiE, Agass.

EucLTPEASTRiD^, Haeckel.
FjBULABiNA, Gray.
EcMnocya/mus, Van Phels.

X E. pusilliis, Gray, . . . .

Fihukwia, Lamk.
X F. australis, Desml.,

F. ovuhnii, Lamk.,
X F. volva, Agass., . . . .

Echinanthidje, a. Ag.
Clypeaster, Lanik.
X C. humilis, A. Ag.,
C. rotundus, A. Ag.,
X G. scutiformis, h&mk., .

X G. suhdepiressus, Agass., .

Echinantlius, Breyn.

E. rosaceits, Gray, . . . .

X E. testudinarius, Gray, .

in Di'i.tli.
Fathoms.

-1350 C.

-1600 a

-245 G.
-190.

-10 C.
-242 B.

-451 B.
-15 C.

-805 B.
-950 C.

-28 a

-20 C.

-120 B.

-118 B.
-120 C

Principal Localities.

j Norway ; Shetland ; Meditei-ranean ; Halifax to New York ;
( Ascension ; Kermadec Islands.

New Zealand.
j Cape of Good Hope ; Mauritius ; Red Sea ; Philippines ;
( New Zealand ; Australia.

Australia.

New Zealand.

Norway ; English Channel.
j Patagonia ; Chili ; New Zealand ; Australia ; Cape of Good
I Hope to Marion Lslands to Kerguelen ; Falkland Islands.
^ West Patagonia ; Straits of Magellan ; New Zealand ; Ker-
l guelen ; Heard Islands.

Mediterranean ; Canary Islands ; C'ape Verde Islands.

Mediterranean ; Caiie Verde Islands.

Norway ; English Channel.

Christmas Islands; Bourbon.

Panama; Ea.st India Islands; Fiji Islands; Mauritius;
New Caledonia ; Sandwich Islands ; Philippines.

Galapagos ; West Coast Central America ; Cape St Lucas.
j Bermudas; South Carolina; West India Islands; Brazil;
( Straits of Florida.

Gulf of California.

Florida ; West Indies ; Surinam ; Bermudas ; Yucatan.
(Sandwich Islands; Japan; East India Islands; Fiji
< Islands ; Red Sea : Mozambique ; Philippines; Kandavu
( Reef; New South' Wales.

New Zealand ; Kandavu Reef.

) Norway; Iceland; Mediterranean; Azores; Florida; Carib-
( bean Islands ; North Brazil.

( Sandwich Islands; Japan; Australia; KingsmiUs Islands ;
\ New South AVales.

Indian Ocean ; Philippine Islands.

Red Sea ; Formosa; North Australia.

( Red Sea ; East India Islands ; New Caledonia ; Philip-
I pines ; Amboyna.
Panama ; San Diego.
S Red Sea ; Philippine Islands ; KingsmiUs Islands ; Japan ;
/ New Caledonia.

) West Coast of Africa; Florida; South Carolina; Brazil;
j West India Islands.

West India Islands ; Florida ; South Carolina.
( Australia ; Japan ; Sandwich Islands ; Gulf of California ;
New South Wales.

REPORT ON THE ECHINOIDEA.

227

Encope, Agass.

E. calif ornica, Verrill..
X E. emarginata, Agass.,
E. (jrandis, Agass.,
E. michelini, Agass.,
E. micropora, Agass.,

PETALOSTICHA, Hsckel.

Cassidulid^e, Agass.

ECHINONID^, Agass.

EchinoiuiLS, Van Pliel.
E. cyclostomus, Leske., .
E. semilunaris, Lamk., .

LAGANID.E, Des. (emend.).

Laganum, Kl.
L. bonani, Kl.,

X L. depressum, hess.,

X L. pnitnami. Barn.,

Feronella, Gray.

X P. decago7ialis, A. Ag., .

P. orbicularis, A. Ag., .
X P. pcronii. Gray, .
P. rostrata, A. Ag.,

ScuTELLiD.*, Agass.

Echinarachnius, Leske.
E. excentricus, Val.,
E. mirabilis, A. Ag.,

E. parraa, Gray, .

Arachnoides, Kl.

A. placenta, Agass.,

Echinodiscus, Breyn.
E. auritus, Leske.,
E. biforis, A. Ag., .
X E. l(Bvis, A. Ag., .

Mellita, Kl.

M. erythraa, Gray,
M. longifissa, Mich.,
M. pacifica, Verrill.,
X M. sexforis, A. Ag.,
M. stokedi, A. Ag.,

M. testudinaia, Kl.,

Astriclypeics, Verrill.
x^. manni, Verrill.,

Rotxda, Kl.

R. augusii, KL,
R. rumphii, KL, .

Eange
in Depth.
Fathoms.

-25 C,

-315 C.
-40 C.

306 B.

-270 B.
-7B,

-70 C.
-11 B.

Priucipal Localities.

Tasmania; East India Islands; PhilippLae Islands.
; Kingsmills Islands; Fiji Islands; Philippine Islands;
; Australia; Zanzibar; Arafura Sea.

Japan; Amboyna.

( Japan; New Caledonia; Bay of Bengal; East India
( Lslands; Philippines; Arafura Sea; Tonga; Tahiti.

Australia; Formosa.

Tasmania ; Philippine Islands ; New South Wales.

New Zealand ; Zanzibar.

California; Alaska; Kamtchatka.
Japan ; Aleutian Islands.

New Jersey; Laliradcr; Vancouver Island; Kamtchatka;
Aleutian Islands ; Japan ; Australia ; India ; Red Sea.

New Zealand ; Australia ; East India Islands ; Burmah.

Zanzibar ; Philippine Islands.

Mozambique ; Red Sea ; Java ; Cape of Good Hope.

Japan; New Caledonia; East lucUa Islands; South Africa.

Red Sea (?).

Panama ; Gulf of California.

Peru.

Brazil; West India Islands ; South Carolina; Bermudas.

Guayaquil ; Panama ; Galapagos.
( Brazil ; West India Islands ; North and South Carolina ;
j Nantucket.

China; Japan.

Liberia ; Senegal ; Cape Verde Islands.
Senegal ; Cape Verde Islands.

Gulf of California.

Brazil ; West Indies ; Yucatan ; Florida ; South Carolina.

Gulf of California.

Yucatan ; Florida.

Panama ; GuU' of California.

Australia ; King.smills Islands ; Zanzibar ; East India Islands.
Florida ; West India Islands

228

THE VOYAGE OF H.M.S. CHALLENGER.

K.ange
in Depth.
Fathom.s.

Principal Localities.

NucLEOLiDiE, Agass.

Ecliinolampas, Gray.
E. alexandri, Lor.,
E. depressa, Gray, ....
E. hellei, Val., ....

X E. oviformis, Gray,

-160 B.
-129 C.

Mauritius.

Straits of Florida ; Caribliean Islands.

Senegal.
I Red Sea ; Molucca ; Cape of Good Hope ; Mauritius ;
( Indian Archipelago.

Bhynchopygus, D'Orbig.
R. carihmarum, Liitk., .
R. padjicus, A. Ag.,

-106 B.

West India Islands.

Galapagos ; Panama ; Gulf of California.

Echinohrissus, Breyn.

E. reccns, D'Orlj., ....

—

New Zealand ; Madagascar.

Nudeolifes, Lamk.
N. epicjonus, Mart.,

—

East India Islands.

AnoeJianiis, Grube.
A. sinensis, Grube,

—

East India Islands.

SpatangiDjE, Agass.

Ananchytid^, Alb. Gras.

Paleopneustes, A. Ag.
P. hystrix, A. Ag.,

21-208 B.

Caribbean Islands.

Platybrissus, Grube.
P. roemeri, Grube,

—

Spatanoina, Gray.

Sjiatamius, Kl.

S. liitkeni, A. Ag.,

X S. purpureus, Leske,

-450 B. C.

Japan.

Norway; Shetland Islands; Mediterranean; Caribbean
Islands ; Bermudas ; Azures.

Maretia, Gray.
X M. alta, A. Ag., ....
M. elliptica, BoL, ....

X M. planulata, Gray,

-800 C.
-25 C.

Japan ; Luzon ; Arafura Sea.

South Sea.
( KingsmUls Islands; China; East India Islands; New Cale-
( donia ; Mauritius ; Australia ; Levuka Reef.

Eupalarjiis, Agass.
X E. vakiiciennesii, Agass.,

—

Australia ; Arafura Sea ; New South Wales.

Lovenia, Des.

L. cordifonnis, Liitk.,

X L. elongata, Gray, ....

X L. subcarinata, Gray. .

-28 C.
-IOC.

Guyaquil ; Gulf of California.
{ Red Sea ; Australia ; Philippine Islands ; Arafura Sea ; Cape
( of Good Hoi)e.

China ; Luzon ; Japan ; Sandwich Islands.

Breynia, Des.
X B. australasice, Gray,

—

Red Sea ; Australia; Japan; Sandwich Islands; Torres Straits.

Echinocardium, Gray.
X E. australe, Gray, ....

E. cordaium, Gray,

X E. flavesccns, A. Ag.,
E. mcditerraiuiim, Gray,

-2675 C.

-85 B.
-150 B.

( New Zealand; Australia; New Soutli Wales; Van Die-
} men's Land ; Japan ; East India ; Cape of Good Hope ;
( Mozambique.

( Norway ; Shetland Islands ; Mediterranean ; Brazil ; Florida ;
( North Carolina.

( Norway ; Shetland Islands ; Cape of Good Hope ; South
( Carolina ; Florida.
Mediterranean.

REPORT ON THE ECHINOIDEA.

229

Leskiad*, Gray.

PalcEOstoma, Lov^n.
P. mirabilis, Lov.,

Brissina, Gray.
Hemiaster, De.s.
X H. cavernosus, A. Ag., .

Tripylus, Phil.

T. excavatus, Phil.,

Eldnobrissus, A. Ag.
■'•B. hemiasteroides, A. Ag.,
B. pyramidalis, A. Ag., .

Brissopsis, Agass.
xB. luzonica, A. Ag.,

X B. bjrifera, Agass.,

Agassizia, Val.

A. scrobicalata, Val.,

Brissus, Kl.

B. carinatus, Gray,

B. ohe.ius, Verrill, .

B. unicolor, KL,

Metalia, Gray.

M. africana, A. Ag.,
M. costcB, Lud.,

X M. Tnaculosa, A. Ag.,

X M. pectoralis, A. Ag.,

M. sternalis, Gray,

Meoma, Gray.

M. graiidis, Gray, .
M. vetitricosa, Liitk.,

Eauge
in Depth.
Fathoms.

-400 C.

[20 C.

-1100 C.
-2135 P.

Linthia, Mer.

L. australis, A. Ag.,
L. rostrata, Smith,

—

Faorina, Gray.

F. cMnensis, Gray,

—

Schizaster, Agass.

S. canalifents, Agass., .

S. gibber idus, Agass.,

*S. japonimis, A. Ag.,

S. philippii, A. Ag.,

X S. ventricoms, Gray.

-37

-8-50 C.
-345 C.

Moira, A. Ag.

M. atropos, A. Ag.,

M. clotho, A. Ag., ....

M. stygia, A Ag., ....

-60 B.

-7B.

-25.
-28 C.
-156 B.

-242 B.

Principal Localities.

China; East India Islands.

j Patagonia ; Chili ; La Plata River ; Straits of Magellan ;
( Kerguelen ; Heard Islands.

Patagonia ; Chili.

Tahiti.
China.

Luzon ; Siam ; New Caledonia ; Tahiti ; Philippines ; Ava-

fina Sea; Japan; New Zealand.
Norway ; Mediterranean ; Florida ; Greenland ; Cape of

Good Hope; Caribbean Islamls.

Peru; Panama; Gulf of California.

Society Islands ; Sandwich Islands ; Ea.st Indies ; Mauritius ;

Philippine Islands.
Panama ; Gulf of California.
West India Islands ; Cape Verde Islands ; Mediterranean.

Sherboro Islands.

Mediterranean ; Capri.

Samoa ; Sandwich Islands ; Australia ; Mauritius ; Panama ;

Arafura Sea ; Gulf of California.
West India Islands ; Florida ; Brazil.
Sandwich Islands ; Society Islands ; East India Islands ;

Philijipiue Islands; Australia; North Caledonia; Red

Sea.

Acapnlco ; Gulf of California.

West India Islands ; Straits of Florida.

Tasmania.
Pacific Lslands.

China ; Sandwich Islands.

Mediterranean.

Red Sea.

Off Japan ; China ; Arafura Sea.

Patagonia.

Fiji Islands ; Philippines ; Siam ; Japan.

West Indies ; North and South Carolina ; Straits of Florida.

Gulf of California.

Red Sea (0; Zanzibar (?).

230

THE VOYAGE OF H.M.S. CHALLENGER.

An examination of the table of Littoral species^ shows us a few species sucli as-

Dorocidaris papillata.
Goniocidaris canaliculata.
Sphcerechinus granulans.
Echinus acutus.
Echinus raagellanicus.
Echinocyamus 2n(s{llus.

Spatangus p)urpureus.
Maretia alta.
Echinocardium australe.
Hemiaster cavernosus.
Brissop)sis lyrifera.
Brissopsis luzonica.

Fihularia australis.

which have an extensive bathymetrical range, in some cases even an extraordinary one ;
the geographical range of the greater number of these species is at the same time very
extended. But out of the great number of the species I have called littoral, in spite of
the great bathymetrical extension of some of them, we find that of the two hundred
and ninety-seven known species two hundred and one are enumerated as littoral, distri-
buted among the foUowinp; families and genera : —

CiDARiD^ (15 species).

Cidaris, 3.
Dorocidaris, 2.
Phyllacantlms 6.
Stephanocidaris, 1.
Goniocidaris, 3.

Arbaciad^ (7 species).
Arbacia, 7.

DiADEMATiD^ (ll species).

Diadema, 2.
Ccntrostephanus, 3.
Echinothrix, 3.
Astrojjyga, 3.

EcHiNOTHUKiDiE (2 species).
Asthenosoma, 2.

EcHiNOMETRAD^ (32 species).

Colohocentrotus, 2.
Heterocentrotus, 2.
Echinometra, 6.

1 There are, of course, associated as littoral, species
beyond the Continental limits ; the exact bathymetrical
it could be stated.

Parasalenia, 1.
Stomopneustes, 1.
Strongylocentrotus, 14.
Sphcerechinus, 3.
Pseudoholetia, 2.
Echinostrephus, 1.

Temnopleukid^ (20 species).

Temnop>leuri(s, 3.
Pleur echinus, 1.
Microcyphus, 2.
Salmacis, 5.
Mespilia, 1.
Amhlypneustes, 5.
Holopneustes, 3.

Teiplechinid^ (20 species).

Phymosoma, 1.
Echinus, 11.
Toxopneustes, 4.
Hippono'e, 3.
Evechinus, 1.

which in some geographical districts do not extend upwards
range is given in the lists of the geographical districts as far as

REPORT ON THE ECHINOIDEA.

231

Or thirty-two genera of Desmosticha, representing one hundred and seven species.

FiBULAEiNA (4 species). Scutellid/E (21 species).

Echinocyamus, 1. Echinarachnius, 3.

Fibularia, 3.

EcHiNANTHiD^ (6 species).
CJypcaster, 4.
Echinanthus, 2.

Laganid^ (7 species).
Lagatvum, 3.
Peronella, 4.

Or thirteen genera of Cl}T)eastrid8e, represented by thirty-eight species.

Arachnoides, 1.
Echinodiscus, 3.
Mellita, 6
Astriclypeus, I.
Rotula, 2.
Encope, 5

EcHlNONElD.^ (2 species).
Echinoneus, 2.

NucLEOLiD^ (9 species).

Echinolampas, 4.
Rhy)}chopygus, 2.
Echinohrissus, 1.
Nucleolites, 1.
Anochanus, 1.

Anajstchytid.^ (2 species).
Paleopncustes, 1.
Platyhrissus, 1.

Spatangina (14 species).

Spatangus, 2.
Maretia, 3.
Eupatagus, 1.
Lovenia, 3.

Breynia, 1.
Echinocardhim, 4.

Leskiad/E (1 species).
Paleostoma, 1.

Brissina (28 species).

Hemiaster, 1.
Trvpyliis, 1.
Rhinobrissua, 2,
Brissopsis, 2.
Agassizia, 1.
Byissiis, 3.
Metalia, 5.
Meoma, 2.
Linthia, 2.
Faorina, 1.
Schizaster, 5.
Moira, 3.

Or twenty-seven genera of the Petalosticha represented by fifty-six species.

These two hundred and one species give us from their geographical distribution
the characteristic littoral faunse, and from the comparison of which I had been led, in the
Revision of the Echini (p. 212), to subdivide the recent Echinid faunae into the following
great realms: — Atlantic, Circumpolar, AustraUan, Antarctic, Pacific, and American. These
subdivisions, of course, have partially lost their significance as will be seen in the
discussion of the geographical lists which follow.

232

THE VOYAGE OF H.M.S. CHALLENGER.

Continental Species.

Range
in Depth.
Fathoms.

Principal LocaUtiea.

DESMOSTICHA, Hieckel.

C I D A R I D ^, Hull.

GoNlociDARiD^, Hjeekel.

DoTOcidaris, A. Ag.
*D. blakii, A. Ag., ....
D. bartletti, A. Ag.,

158-450 B.
76-398 B.

Florida; Carilibean Ishwids.
Caribbean Islands.

Poroddaris, Des.

P. sharreri, A. Ag.,

123-351 B.

Caribbean Ishands.

Goniocidaris, Des.
*G. floriyera, A. Ag.,

100-129 C.

PhUippines ; Indian Aichipelago.

SALENID.E, AgaSS.

Salenia, Gray.

S. gcesmim, Lov., ....
*.S'. hastigera, A. Ag.,
S. pattersoni, A. Ag.,

xS. varispiiui, A. Ag.,

[180 J.
100-1850 C.
175-450 B.

60-1675 B.C.

We.st India Islands.

Philippines ; Kermadec ; Indian Archipelago ; Azores.
Caribbean Islands.
) Florida ; Caribbean Islands ; North Brazil ; Ascension ;
Azores; Canary Islands.

Arbaciad.e, Gray.

Podocidaris, A. Ag.
X P. smlpta, A. Ag.,

138-390 B.

Florida; Caribbean Islands.

Galophurus, Agass.

G. floridamis, A. Ag.,
X C. maillardi, A. Ag.,

56-1323 B.

82-102 C.

Florida ; Caribbean Islands.

Bourbon; Philippines; Amboyna; Indian Archipelago.

D1ADEIIATID.B, Peters.

Aspidodiadema, A. Ag.

*/l. toiisum, A. Ag.,

A. jacobyi, A. Ag.,

100-1700 C.

95-287 B.

Philippines; Kermadec; Macio.
Caribbean Islands.

Micropyga, A. Ag.
*ilf. tuberculatwa, A. Ag.,

100-610 C.

Philippines; Fiji Islands.

EcHixoTHDRiDiE, Wy. Thom.

Asthenosoma, Grube.
*A. gracile, A. Ag.,

A. hystrix, A. Ag.,
*.4. jtellucidum, A. Ag., .
*.-l. tessetkUmn, A. Ag., .

A. reyiioUhii, A. Ag., .

150-255 C.
1 00-445 B. P.
100-129 C.
100-115 C.
180-375 B.

Philippines ; New Zealand.

Florida; North East Atlantic ; Caribbean Islands.

Philippines ; Indian Archipelago.

Philippines.

Caribbean Islands.

Phormosom-a, Wy. Thom.

P. sigsbei, A. Ag., ....

120-1250 B.

Caribbean Islands.

EcHiNiD^, Agass.
TEMNOPLEnRiD.s;, Des.

Temnechimis, Forbes.
T. TMiculatiis, A. Ag.,

30-600 B. J.

Florida ; Caribbean Islands ; Josephine Bank.

Trigonocidaris, A. Ag.

T. alhida, A. Ag., ....

60-450 B.

Florida; Caribbean Islands ; Josephine Bank.

TRIPLECHINIDiE, A. Ag.

Hemipedina, Wright.
H. cubensis, A. Ag.,

138-270 B.

Straits of Florida.

REPORT ON THE ECHINOIDEA.

233

Echinus, Rond. (Linn.)
xE. elegans, Diib. o. Kor.,

E. gracilis, A. Ag., ■
*JJ. hon-idiis, A. Ag.,

E. microstoma, Wy. Thom.,
xE. norvegicus, Diib. o. Kor.,

E. wallisii, A. Ag.,

PETALOSTIUHA, Hteckel.

Cassiddlid^, Agass.

NUCLEOLID.E, Agass.

Neolampas, A. Ag.

N. rostdlata, A. Ag.,

Gonoclypus, Agass.
C. sigsbii, A. Ag., .

Catopygus, Agass.
*C. receiis, A. Ag., .

Spatangid^, Agass.
Ananchttid^e, All). Gras.

Palceotropus, Lov.

P. josephiruB, Lov., ;

Linopneustes, A. Ag.

L. longispinus, A Ag.,

Paleopneustes, A. Ag.

P. cristatm, A. Ag., ,

Spatangina, Gray:

Spatangus, KL

X .§. raschi, Loven, .

Nacopatagus, A. Ag.
N. gracilis, A. Ag.,

Echinocardium, Gray.

.B. pennatifidum. Norm.,

Brissina, Gray.

Rhinobrissus, A. Ag.

iJ. micrasteroides, A. Ag.,

.iljwssiKia, VaL

A. excentrica, A. Ag.,

Brissiis, KL

='=P. daincsi, A. Ag., .

Schizaster, Agass.

X S. fragilis, Agass,, .

*S. moseleyi, A. Ag.,
S. orbignymius, A. Ag., .

Periaster, D'Orb.

X P. limicola, A. Ag.,
Moiropsis, A. Ag.

^M. claudicans, A. Ag.,

in Depth.
Fathoms.

80-1350 C.

93-200 B.
[175 C.

150-450 P.
80-2435 B. P.
257-1047 B.

Principal Localities.

100-690 B. P.

84-450 B.
[129 C.

82-250 B.J.
28-373 B. ,
56-150 B.

1 50-300 P. C.
[65 B.

j Norway ; Mediterranean ; Tristan da Cunha ; New York ;
( Papua.

Florida ; We.st India Islands.

Straits of Magellan ; West Patagonia.

West Coast of Scotland and Ireland.

Norway ; Mediterranean ; Japan ; West Patagonia.

Atlantic Coast of U.S. (Southern and Middle States).

Florida; CariUjean Islands; North-East Atlantic.
Straits of Florida ; Yucatan.
Indian Archipelago.

Caribbean Islands ; Azores.

Caribbean Islands.

Florida ; Caribbean Islands.

j German Ocean ; Azores ; Shetland Islaiids ; Cape of Good
I Hope.

Juan Fernandez.

79-121 B. Northumberland; Shetland Islands ; Florida.

175-242 B.
46-391 B.
120-450 C.

71-955 B.

40-1375 C.

92-1557 B.

28-118 B. C.

[129 C.

Caribbean Islands.

Florida; Caribbean Islands.

North Brazil ; Azores.

Norway ; Gulf of St Lawrence ; Florida ; Caribbean
Islands ; Gulf of Maine ; Cape of Good Hope.

Marion Idands: Kerguelen; West Patagonia; Straits of
Magellan.

Caribbean Islands.

Gulf of Mexico ; Arafura Sea. .

Indian Archipelago.

(ZOOL. CHALL. EXP. — PART IX. — 1881.)

130

234

THE VOYAGE OF H.M.S. CHALLENGER.

The following species are also fouud within the continental limits. They are either
littoral species (L."*") which extend beyond the ordinary range of the littoral species into
the continental limits, or they are littoral species (L."^+) which extend not only into the
continental limits, but also into the limits of the abyssal fauna ; some of the species
extending nearly to the greatest dejath at which Echinids have been collected.

DESMOSTICHA, Hteckel.

ClDARID^, Miill.

GONIOCIDARID^, HcBckel.

Cidaris, Kl.
L. +x G. tribidoides, BL,

Dorocidaris, A. Ag.

L +* D. hract'eata, A. Ag.,
L.++X-0. papillata, A. Ag., .

Goniocidaris, Des.

L.++xff. canaUculata, A. Ag.

Arbacid^, Gray.

Arhacia, Gray.

L. + x A. d-tifresnii,Gi3.y,
L. X A. punctulata, Gray,

EcHiNOMETRAD^, Gray.

Echinometra, Rondel. (Breyn.).
L. +x .B. subaiu/ularis, Desml.,

Sphcerechmus, Des.

L. +x iS. granidaris, A Ag.,

Range
in Depth.
Fathoms.

-250 B.

-100 c.
-874 B.

-1975 C.

-175 C.
-125 B.

-250 B.
-400 C.

Principal Localities.

South Carolina ; West India Islands ; Cape Palmas.

AmbojTia.

Norway ; Philippines ; Sonth Atlantic.

Patagonia ; Zanzibar ; Australia ; Southern Ocean.

Patagonia ; Chili.

Long Island Sound ; Yucatan.

Senegal ; "West India Islands ; Ascension Island.

Mediterranean ; St Vincent.

EcHiNiDiE, Agass.

Temnopleurid^, Des.

Temnopleuriis, Agass.

L. +x T. hardiinckii, A. Ag., .
L.+x T. reynaudi, Agass.,

-129 C.

-275 C.

Japan ; Arafura Sea.

Ceylon ; East India Islands ; New Zealand.

SalTTMcis, Agass.

L. + x S. dussumieri, A^ss., .

-100 C.

China Seas ; East India Islands.

Triplechinid^, a. Ag.

Echinus, Rond. (Linn.)
L.++ xE. amhis, Lamk.,
L.++xE. nrngellanicus, Phil.,
L. +x £. nwrgaritacens, Lam.,
\j.+E. melo, Lam., ....

-1350 C.

-1600 C.

-245 C.

-190

Norway ; Ascension Island.
Patagonia ; Cape of Good Hope ; Australia.
Patagonia ; New Zealand : Heanl Island.
Mediterranean Cape Verde Islands.

Toxopneustes, Agass.
L. + x r. variegatus, A Ag., .

-300 B.

Bermudas ; West India Islands ; Brazil.

Hippono'e, Gray.-

Ij.+H. esculenta, A. Ag.,

-451 B.

West India Islands.

REPORT ON THE ECHINOIDEA.

235

Range
in Depth.
Fathom.s.

Principal Localities.

CLYPEASTRID,^, Agass.

EucLTPEASTRiD^, Hieckel.

FiBULABiNA, Gray.

Eehinocyamus, Van Phelps.
L.++xE. 2msillus, Qmj,

-805 B. C.

Norway ; Azores ; Florida ; Brazil.

Fibularia, Lamk.

L. + + y,F. australis, Desml., .

-950 C.

Japan ; Sandwich Islands ; New South Wales.

ECHINANTHID^, A. Ag.

Clypeaster, Lamk.

L.+ X. G. subdepressns, Agass.,

-120 B.

West Coast of Africa ; Caribbean Islan ds.

Echinanthus, Breyn.
L.H- E. rosaceus, Gray,
L.+ x E. testadinarius, Gray,

-118 B.
-120 C.

West India Islands ; South Carolina.
Australia ; Japan ; Gulf of California.

Laganid-e, Des. (emend.)

Peronella, Gray.

L. + x P. decagonalis, A. Ag., .

-315 C.

Japan ; East India Islands ; New Caledonia ; Tonga.

SCCTELLID.S;, Agass.

Echinarachniiis, Gray,
L.+ E. parma, Gray,

-306 B.

( East Coast U.S. ; Labrador ; Red Sea ; Australia ; Japan ;
( Kamtchatka ; Aleutian Islands.

Mellita, Kl.

L+ M. sexforis, A. Ag.,

-270 B.

Brazil ; West India Islands ; South Carolina.

PETALOSTICHA, Hreckel.

C A .s s I D u L I D jE, Agass.

NucLEOLiDvE, Agass.

Echinolampas, Gray.

L.+ E. depressa, Gray,

L.+ x E. oviformis, Gray, ■ .

-160 B.
-129 C. .

Cariljbean Islands.

Red Sea ; Cape of Good Hope ; Indian Archipelago.

SPATANGIDiE, AgaSS.

Spatangina, Gray.

Spatangus, Kl.

L.+ x S. |)MrpMreus, Leske,

-450 B. C.

Norway ; Mediterranean ; Caribbean Islands.

Maretia, Gray.

L.++xAf. aZto, A. Ag. .

-800 C.

Japan ; Luzon ; Arafiira Sea.

Echinncardium, Gray.
L.++xjB.a!ts<ra/e, Gray,
L. + X i?. flavescens, A. Ag., .

-2675 C.
-150 B.

New Zealand ; Australia ; Mozambique.
Norway ; Cape of Good Hope ; Florida.

Brissina, Gray.

Hemiaster, Des.

L.+ x S. cavemosiis, A. Ag., .

-400 C.

Patagonia ; Chili ; Kerguelen.

Brissopsis, Agass.

L. + +xB. iuzonica, A. Ag.,
1^. + + xB. lyrifcra, Aga.ss.,

-1100 C.'
-2435 P.

Luzon ; Siam ; New Caledonia ; Japan ; New Zealand.
Norway; Caribbean Islands; Cape of Good Hope.

Metalia, Gray.

Jj. +x M.pectoralis, A. Ag., .

-1.56 B.

West India Islands ; BraziL

Meoina., Gray.

L.+ M. ventricosa, Liitk.

-242 B.

West India Islands ; Straits of Florida.

Schizaster, Agass.

L.+x S. ventricosus. Gray,

-345 C.

Fiji Islands ; Philippines ; Siam ; Japan.

236

THE VOYAGE OF H.M.S. CHALLENGER.

The preceding table gives us the range of a group of species of which, while many of
them extend towards the littoral area, the upper limit is usually near the 100 fathom line,
and we find here a proportionally larger number of species extending into deep water, into
the next bathymetrical subdivision, than in the littoral species. The usual limit of the
continental species in depth is from 350 to 450 fathoms. There are forty-six continental
species of which ten extend to great depths. The species which have an exceptionally
great bathymetrical range are — Salenia hasiigera and Salenia varispina, Ccelopleurus
Jloridamcs, Aspidodiadema tonsum, Phormosoma sigsbei. Echinus elegans. Echinus norve-
gicus, ScUzaster fragilis, Schizaster moseleyi, and Schizaster orhignyanus.

The continental species are distributed as follows, excepting, of course, the few species
which extend beyond the usual littoral limit downwards, and the species of this group
which reach upwards from the abyssal district, and thus produce a bathymetrical mixture
similar to the mixture we might obtain of successive geological horizons : —

EcHmoTHURiD.-E (6 species).

Asthenosoma, 5.
Phormosoma, 1.

CiDAEiD.E (4 species).
Dorocidaris, 2.
Porocidaris, 1.
Goniocidaris, 1.

Salenid^e (4 species).
Salenia, 4.

ARBACiADiE (3 species).
Podocidaris, 1.
Coelopleunis, 2.

DiADEMATiD.E (3 species).
Aspidodiadema, 2.
Micropyga, 1.

Or twenty-nine species of Desmosticha distributed among fourteen genera. The
Clypeastridse have entirely disappeared.

Among the Petalosticha there are seventeen species distributed among the following
fifteen genera.

Temnopleurid^ (2 species).

Temnechinus, 1.
Trigonocidaris, 1.

TRiPLECHiNiDiE (7 species).

Hemipedina, 1.
Echinus, 6.

NucLEOLiD^ (3. species).

Neolampas, 1.

Conochipus,'!.

Catopygus, 1.
Ananchytid^ (3 species).

PalcBOtropus, 1.

Zdnopneustes, 1.

Paleopneustes, 1.

Spatakgina (3 species).

Spatangus, 1.
Nacopatagus, I.
Echinocardium, 1 .

REPORT OX THE ECHINOIDEA.

237

BuissiNA (8 species).

Rhinobrissus, 1.
Agasmzia, 1.
Brissus, 1.

Schizcoster, 3.
Penaster, 1.
Moiropsis, 1.

Among these coutiueutal species there are already quite a number of the deep-sea
genera, or of genera characterised by their ancient geological facies.' Those which
appear are —

Salenia.

Porocidaris.

CoeloiJileurus. '

Phormosoma.

Asthenosoma.

Temnechinus.

Trigonocidaris.

Catopygus.

Conoclypus.

Neolampas.

Pcd<^otrop)ns.

Linopneustes.

Paleopneustes.

Periaster.

The analysis of the supplementary continental table shows us that the forty-six
species of the truly continental fauna are associated below the 100 fathom line with no
less than thirty-seven littoral species, eleven of which even extend beyond the usual limits
of the continental species far into the oceanic fauna—

Abyssal or Oceanic Species.

Range

■ in Depth.

Fatlioms.

Principal Localities.

DESMOSTICHA, Hajckel.

CiDARIDiE, Mull.

GoNiociDARiD^, Hreekel.

Porocidaris, Des.
*P. elegans, A. Ag.,
P. purpurata, Wy. Thorn., .

Arbaciad/E, Gray.

Podocidaris, A. Ag.
*P. prionigera, A. Ag., .
P. scutafa, A. Ag.,

DiADEMATiD^, Peters.
Aspidodiadema, A. Ag.
*A. microtuberculatum, A Ag.,
A. antillarum, A. Ag., . . ■ .

EcHiNOTHURiD/E, Wy. Thom.

Asthenosoma, Grube.
*j4. coriaceum, A Ag., .
A. fcnestratum, Wy. Thom., .

410-500 C.
[542 P.

1050-1075 C.
[580 B.

804-2225 B.C.
451-1200 B.

240-315 C.
[445 (?) P.

Philip 5ines ; Papua ; New South Wales.
EockalL

Philippines ; New Guinea.
Caribbean Islands.

( Macio ; Caribbean Islands ; Brazil ; Tristan da Cunha ;
( Chili ; Juan Fernandez.
Caribbean Islands.

Fiji Islands.

RookaU ; Bay of Biscay ; West Coast of Portugal.

238

THE VOYAGE OF H.M.S. CHALLENGER.

Phormosoma, Wy. Thorn.
*P. asterias, A. Ag.,
*P. hurmria, A. Ag.,
*P. hoplacantha, Wy. Tliom.,
*P. Iucule7itum, A. Ag., .
P. placenta, Wy. Thorn.,
*P. rigidum, A. Ag.,
*P. ienwc, A. Ag., .
*P. uramis, Wy. Thorn.,

P. petersii, A. Ag.,

ECHINID.B, Agass.

Temnopledrid.'E, Des.

Prionechinus, A. Ag.
*P. sagittiger, A. Ag.,

Cottaldia, Des.
*C. forbesiana, A. Ag.,

Trigoriocidaris, A. Ag.
*r. monolini, A. Ag.,

CLYPEASTRIDJE, Agass.
EcHINOCONIDiB, D'Orb.
Pygaster, Agass.

P^ relictus, Lov., .

PETALOSTICHA, Hceckel.
SPATANGiD.a;, Agass.

P0URTALESI.«, A. Ag.

Pourtalesia, A. Ag.
*P. carinata, A. Ag.,
*P. ceratopyga, A. Ag.,
*P. higpida, A. Ag., .
• P. jeffreysi, Wy. Thorn.,
*P. laguiicula, A. Ag.,
P. miranda, A. Ag.,

P. phiale, Wy. Thom.,

*P. rosea, A. Ag., .

Spatagocystis, A. Ag.
*S. chalUngeri, A. Ag.,

Echiiiocrepis, A. Ag.
*£. cuneata, A Ag.,

Urechinus, A. Ag.
*Z7. naresiamis, A. Ag.,

Gystechinus, A. Ag.

*(7. chjpeatus, A. Ag.,

*C vesica, A. Ag., .
*(7. wyvillii, A. Ag.,

Calynine, Wy. Thorn.
*'0. reJicfa, Wy. Thom.,

Rauge
in Depth.
Fathoms.

[2160 C.
255-1050 C.
410-1375 C.
256-1050 C.
500-800 P.
"00-1400 C.
1875-2750 C.
1000-1525 C.

399-1224 B.

700-1070 C.
310-315 C.
[520 C.

[180 J.

1950-2225 C.

1950-2225 C.

1600-1975 C.

[690 P.

345-2900 C.

242-1215B,P.
1215-1975
P. C. Val.
[2600 C.

1600-1950 C,

[1600 C.

1200-1800
B.C.

1050-1915 C,

1675-2225 C.
1375-1825 C.

620-2650 C.

Principal Localities.

Juan Fernandez to Chili.
Japan ; Philippines.

Japan ; New South Wales ; Juan Fernandez to Chili.
Philippines; Indian Archipelago.
West Coast of Scotland and Ireland.
New South Wales.

Sandwich Islands to Low Archipelago ; Japan.
South Portugal ; Azores.

Caribbean ; Atlantic Coast of U.S. (Middle and Southern
States).

Philippines ; New South Wales.
Fiji Islands.
Kerniadec Islands.

West India Islands.

Heard Islands to Antarctic ; Juan Fernandez to Chili.

Heard Islands ; Australia ; Juan Fernandez to Chili; Antarctic,

Marion Islands to Australia.

Faroe Islands ; Shetland Islands.

Japan to Sandwich Islands ; Arafura Sea ; New Zealand.

Florida ; Caribbean Islands ; Shetland Islands.

■ Kerguelen to Australia; Eockall ; North Atlantic.

Sandwich Islands to Low Archipelago.

Antarctic to Australia.

Antarctic to Australia.

Antarctic to Australia ; Juan Fernandez to Chili ; Carib-
bean Islands.

5 Philippines ; Tristan da Cunha to Bahia to Buenos
( Ay res.

Antarctic ; Kerguelen to Australia ; Juan Fernandez to Chili.

Antarctic ; Kerguelen to Anstralia ; Juan Fernandez to Chili.

Azores.

REPORT ON THE ECHINOIDEA.

239

Kaiige
in Depth.
Fathoms,

Priiicip.il Localitie.s.

Ananchytidje, Alb. Gras.

Palwotropus, Loven.
*P. lovd/ii, A. Ag., ....
P. thomsoni, A. Ag.,

[375 C.
[233 B.

Philippines.
Caribbean Islands.

Argopatagus, A. Ag.
*A. vitreus, A. Ag.,

[800 C.

Arafnra Sea.

Genicopatagus, A. Ag.
*(r. affinis, A. Ag., ....

[1950 C.

Antarctic ; Kerguelen to Australia.

Homolampas, A. Ag.,
X H. fragilis, A. Ag.,
*H. fulva, A. Ag., . '. . .

300-1920 B.
2425-2475 C.

Straits of Florida ; Brazil ; Josephine Bank.
Sandwich Islands to Low Archipelago.

Linopneustes, A. Ag.
*L. murragi, A. Ag.,

345-375 C.

Philippines ; Japan.

Bkissina, Gray.

Remiaster, Des.

H. expergitus, Lov.,
*!/■. gibhosm, A. Ag.,
*7r. zonatus, A. Ag.,

if. mentzii, A. Ag..-

4fi4-4S5 B. J.
345-800 C.
620-750 C.
170-576 B.

Caribbean Islands ; East Atlantic ; West Coast of Spain.
Japan ; Arafura Sea.
Baliia ; Canary Islands.
Caribbean Islands.

Cionobrissus, A. Ag.
*(7. revinctus, A. Ag.,

[800 C.

Arafura Sea.

Aerope, Wy. Thom.
*vl. rostrata, Wy. Thorn., . . |

800-1750
C. Val.

i Arafura Sea ; Bay of Biscay ; Davis Straits.

.4ces<e, Wy. Thom.
*4. bellidifera, Wy. Thom., .

[2G00 C.

( Sandwich Islands to Low Archipelago ; Buenos Ayres
( Tristan da Cunha ; Canary Islands.

to

When we come to the strictly deep-sea species, we find that many of them encroach at
their upper limit into the lower limit of the continental species. Only a comparatively
small number' of species can be called abyssal, the lower limit of these not being, how-
ever, any greater than that of many of the species which have a higher continental
limit.

There are fifty deep-sea species, of which twenty-seven either approach or encroach
upon the lower limits of the continental species. Of these forty-six there are twelve which
extend to a greater depth than 2000 fathoms, 2900 fathoms being the greatest depth at
which any Sea-urchin has been dredged by the Challenger; fifteen other species extend to a
greater depth than 1000 fathoms and less than 2000. Of the twenty-four species which
approach or extend to the lower continental limit, five extend to beyond 2000 fathoms,
two to beyond 1500 fathoms, and three to over 1000 fathoms. The abyssal species
are distributed as follows : —

240

THE VOYAGE OF H.M.S. CHALLENGER.

CiDARiD.E (2 species).
Porocidaris, 2.

Arbaciad^ (2 species).
Podocidaris, 2.

Diadematim; (2 species).
Aspidodiadevia 2.

ECHINOTHURID/E (11 SpCcies).

Asthenosoma, 2.
Phormosoma, 9.

Temnopleurid^ (3 species).
Prionechinus, 1.
Cottaldia, 1.
Jrtgonocidaris, 1.

Or twenty species of Desmosticha representing nine genera.

The Clypeastridse have completely disappeared with the exception of Pygaster (this,
however, like a few other species here included in the abyssal list may hereafter prove to
belong to the continental fauna) and of the few littoral species having great bathy-
metrical range.

Among the Petalosticha we find a great development of species of genera represented
in the Tertiary and Cretaceous periods. Of the Desmosticha the families characteristic of
the littoral faunae have either completely disappeared or are but scantily represented by
genera with an ancient geological facies, or genera having a considerable range in time.
We find the Petalosticha distributed in the following genera : —

Brissina (7 species).
Cionobrissus, 1 .
Aerope, 1.

Aceste, 1.
Hemiaster, 4.

AVhile all the other species (twenty-two) belong to the typical deep-sea groups of
Pourtalesise and Ananchytidse distributed in tlie following genera : —

Pcdceotropus, 2.
Homolampas, 2.
Linopneustes, 1.
Argopatagus, 1.
Urechinus, 1.
Cystechinus, 3.

Calymne, 1.
Genicopatagus, 1 .
Echinocrepis, 1.
Spatagocystis, 1 .
Pourtalesia, 8.

Or twenty-nine species of Petalosticha distributed in fifteen genera.

In each one of the bathymetrical belts- we have- recognised, we find, as an inspection
of the table will show, an encroachment at both the upper and lower limits of each zone-
by exceptional species, which wander into far greater depths, and become associated in
succession with the species of the preceding and succeeding zones, and thus modify to a
considerable extent the characteristic physiognomy of each bathymetrical belt.

REPORT ON THE ECHINOIDEA.

241

Supplementary Abyssal List.

Associated with the 50 strictly abyssal species are 24 other species, of which 14
marked C.''" on the supplementary list are continental, 1jut have a very much greater
range in depth than the continental species as a whole ; the other 1 0 are littoral species,
marked L.++, which extend in some geographical district or other, not only into the
continental range, but far into the abyssal fauna.

DESMOSTICHA, Hreckel.

ClDARIDiE, Miill.

GONIOCIDARID^, Hfeckel.

Dorocidaris, A. Ag.

'L. + + y.D. papillata, A-. A.Q., .

Qoiiiocidaris, Des.

L. ++ G. canaliculata, A. Ag.,

SaleniDjB, Agass.

Salenia, Gray.

C. +* 8. hastigera, A. Ag.,
C. +x S. varispina, A. Ag., .

ARBACiADiE, Gray.

Cxlopleurus, Agass.
C. + C. floridanus, A. Ag., .

DiADEMATiD^, Peters.

Aspidodiadeirui, A. Ag.
C. +* A. tonsum, A. Ag.,

Micropyga, A. Ag.

C. +* M. tuherculatuvi, A. Ag.,

EcHiNOTHURiDiE, Wy. Thom.

Phormosoma, Wy. Thom.
0. + P. sigsbci, A. Ag.,

E c H I N I D .E, Agass.

TEMNOPLEDRID.E, DeS.

Temnechiniis, Fortes.
C. + T. nvxcidatus, A. Ag., .

TRIPLECHINID.E, A. Ag.

Echinus, Eoncl. (Linn.).
L.++X-B. acutus, Lanik.,
C. + X -B- elegans, Dub. o. Kor.,
h.++xE. magellanicus, Pliil., .
C. +x -B. norvcgimis, Diib. o. Kor.,
C.+ E. wallisii, A. Ag., .

Range
in Depth.
Fathoms.

Principal Localities.

-874 B.
-1975 C.

100-1850 C.
60-1675 B.C.

56-1323 B.

100-1700 C.
100-610 C.

120-1250 B.
30-600 B. J.

-1350 C.
80-1350 C.

-1600 C-
80-2435 B. P.
257-1047 B.

Caribbean Islands ; Pliilippines ; La Plata ; South Atlantic.
Patagonia ; Australia ; Cape of Good Hope ; Antarctic.

PhilippLues ; Indian Arcliipelago.
Florida; Canary Islands.

Florida ; Caribbean Islands.

Philippines; Kennadec; Macio.
PMlippities ; Fiji Lslands.

West India Islands.
Caribbean Islands Azores.

Norway ; Ascension ; Kennadec ; New York.
Norway ; South Atlantic ; Papua ; New York.
Patagonia ; Australia ; Cape of Good Hope ; Antarctic.
Norwav ; Mediterranean ; Florida ; Japan.
Atlantic Coast of U.S. (So. and Mid. States).

(ZOOL. CHALL. EXP. — PART IX. — 1881.)

I 31

242

THE VOYAGE OF H.M.S. CHALLENGER.

in IX-jpth.
Fatlionis.

Principal Localities.

CLYPEASTRID^, Agass.

Edcltpeastrid^, Hfeckel.

FiBULARiNA, Gray.

Echinocyamus, Van Phelps.
L. + +X-B. jJMsiWifs, Gray,

-805 B.

Norway ; Azores ; Caribbean Islands ; Brazil.

Fibularia, Lamk.

L.++xF. austmliSj'Desinl.,

-950 C.

Jajjan ; Sandwicli Islands ; Xew Soutli Wale.s.

PETALOSTICHA, Hreckel.

Cassidulid^, Agass.

NDCLEOLID.E, AgaSS.

Neolampas, A. Ag.

C. + N. rostellata, A. Ag., .

100-690 B. P.

Nortli-East Atlantic ; Caribbean Islands.

Spatangid^, Agass.

Spatangina, Gray.

Maretia, Gray.

L.+ + xM. aZto, A. Ag., .

-800 C.

Arafura Sea ; Japan.

Echinocardiiim, Gray.
L.++X-B. australe, Gray,

-2675 C.

( New Zealand ; Australia ; East India Lslands ;
1 Good Hope ; Mozambique.

Cape of

Brissina, Gray.

Brissopsis, Agass.

11. + + xB. luzonica, A. Ag.,

'L.++xB. lyrifera, Agass.,

-1100 C.
-2435 P.

-

Luzon ; New Caledonia ; Japan.
^ Norway ; Mediterranean ; Cape of Good Hope ; Caribbean
( Islands; Greenland.

Schizaster, Agass.

C. +x S. fragilis, Agass.,

C. +* S. moseleyi, A. Ag.,
C. +8. orbignyanus, A. Ag.,

83-955 B.

40-1375 C.
92-1557 B.

( Norway ; Gulf of St Lawrence ; Florida ; Cape
/ Hope ; Caribbean Islands.
' Marion Island ; Straits of Magellan.
Caribbean Sea.

of Good

To recapitulate, we may state that of the 297 known species of Echinids no less than
201 species are littoral, 46 are continental, and 50 abyssal or oceanic. Of the littoral
species, 36 extend beyond the 100 fathom line into the continental range, and of these
10 also extend beyond it into the abyssal range. The species having the greatest
bathymetrical range (over 1000 fathoms) are —

Goniocidaris canalicuhda,
EcJiinus ac7dus,
Ecliimis magellanieus, .
Erhinocardium ausfrale,
Brissojists luzoritca,
Brissopsis lyrtfera,

littoral to 1975 fathoms.

1350
„ 1600

2G75
„ 1100

2435

Of the continental species 1 4 extend beyond the usual limits of the continental range

REPORT ON THE ECHINOIDEA.

243

into the abyssal fauna ; and the following continental species have an extreme range of
more than 1000 fathoms : —

Salenia hastic/era,

100-1850 fatlioms

Salenia varisyinu,

GO-1675

))

Gmlopleunis florldanus,

56-1323

?)

Aspidodiadema ionsum,

100-1700

!)

Phormosomu sigsbei,

120-1250

5>

Hchinus elegans,

80-1300

J)

Echinus norvegkiis, .

80-2435

JJ

Scliizaster moseleyi, .

40-1375

)>

Schizaster orhifjmjaims,

n^Yiim nnrl TT

il\7iln.vi

92-1557

ri Timrp n rnno'P

nf IK

1000 fathoms. Finally, of the abyssal species the following have a greater range than
1000 fathoms : —

Aspidodiadema inierotahercalatum,
Pourtalesia Jaguncula,
Galymne rclirta,
Homolavipas fnujilis,

804-2225 fatlioms.
34.5-2900
620-2650 „
300-1920

and quite a numl^er of other species of which the range approaches 1000 fathoms but is
below it, showing thus that a very large proportion of the known Echinids have an ex-
traordinary l)athymetrical range, and that distributed as these are among all the families
and principal groups of Echinids, it is evident we cannot look upon pressure alone as
a very important feature in the limitation of the l^athymetrical range, but that we must
rather look to the difference of temperature characterising the three belts here recognised
as the principal element in the distribution of the Echinids in the depths of the ocean.

The genera characteristic of the littoral faunae which disappear from the continental
limits, exclusive of the species having a great bathymetrical range, are the greater
number of the species of Cidaridee —

Cidaris.
Phyllacanthus.

The greater number of the Diadematidse-

Diadema.
Centrostephcmus.

All the Echinometradse —

Colobocentrotus.

Heterocentrotus.

Echinometra.

Pavasalenia.

Stomopneustes.

Stephatiocidaris.
Arbacia.

Echinoilirix.
Astropyga.

Strongylocentrotus.
SphcBrechinus.
Pseudoboletia
Echinostrephus.

244

THE VOYAGE OF H.M.S. CHALLENGER.

Nearly all the Temnopleuridse-

Teimiojileurus.
Pleurechinus.
Microcyphus.
Salmacis.

Mespilia.

Amhlypneustes.

Holojyneustes.

And of the Trij^lechiuidse only a few species of Echinus are left, while Hemip)edina,
Phymosoma, Toxopncustes, Hipponoe, and Evechinus have no representatives.

All the littoral Clypeastridae have disappeared from among the continental species
with the exception of those having a wide bathymetrical range (^). There is not a single
typical continental species belonging to either —

'^ Echinocyaiims.
^Fibularia.

Clypeaster.

Echinanthtis.

Laganum.
^Peronella.
^ Ecliinarachnius.

Arachnoides.
Echinodiscus.
""Mellita.
Astriclypeus.
Rotida.
Encope.

Among the Petalosticha the following genera are missing : —

Echinonetis.
■^ Echinolampas.
Rhynchopygus.
Echinohrissus.
Nucleolites.
Anochanus.
Platyhrissus.
Maretia.
Lovenia.
Breynia.

Palceostoma.
Tripylus.
'^Brissopsis.
Brissus.
Metalia.
Meoma
Linthia.
Faorrda.
Moira.

The follo-ftdng genera are rejjresented by different species in the littoral and in the
continental bathjTnetrical ranges : —

Dorocidcms.

Goniocidaris.

Asthenosoma.

Echinus.

Spatangus.

Echinocardium.
Rhinobvissus.
Agassizia.
Schizaster.

REPORT ON THE ECHINOIDEA.

245

Showing how sharply the continental genera contrast ^\'ith those of the littoral faunae.
Of the 72 genera represented in the different littoral faunse only 9 are common to
both the littoral and continental ranges, when we separate the species which are
littoral, and happen to extend either into or through the continental range into the
abyssal range, and as these species are very numerous, considerable care must be taken
to separate them from the continental species. They are added to the continental lists,
and are marked L.+ when extending only into the continental range, and L.++ when they
extend also into the abyssal range ; while when we compare the littoral genera and the
abyssal we find only two genera, Asthenosoma and Hemiaster, which have strictly
characteristic littoral species.

Comparing in the same way the continental and the abyssal ranges, the following
genera found in the continental range do not extend into the abyssal : —

Dorocidaris.

Goniocidaris.

Scdenia.

Cceloiileurus.

Microinjga.

Temnechmus.

Hemipedina.

Neolamixis.

Conoclypus.

Catopygus.

Paleopneustes.

Spatangus.

Nacop>cttagxis.

Echinocardium.

Rhinohrissus.

Agassizia.

Schizaster.

Moiropsis.

That is, in addition to the 9 genera of which there are representative species in both
the Httoral and continental ranges, there are 11 genera eminently characteristic of the
continental range ; while the following genera have representative species both in the
continental and abyssal ranges : —

Porocidaris.
Podocidaris.
Asjndodiadema.

Asthenosoma.
Phormosoma.
Trigonocidaris.

Or only 6 genera thus far out of 47 which are found extending from the continental
line to the abyssal range and including both ; whde the following genera are eminently
abyssal, and have thus far not been found to extend into the continental range among
the recent species.

Spatagocystis.

Prionechinus.
Cottaldia.
Pygaster.
Pourtalesia.

EcMnocrepis.

Urechinus.

Cystechinus.

246 THE VOYAGE OF H.M.S. CHALLENGER.

Calymne. lAnopneustes.

Palceotroiyus. Cionohrissus.

Genicojyatagus. Aerope.

Homolampas. Aceste.

That is,^we have 16 genera which are eminently abyssal out of the 24 genera extend-
ing into the abyssal region, exclusive, of course, of the species which have an abnormal
bathymetrical range and spread from the littoral to the greatest depth at which Echinids
have been dredged. The abyssal genera belong nearly all to a new group of Spatangoids
related to those of the Chalk and have no allies among the littoral species.

Geographical Range of the Continental and Abyssal Species.

As regards the geographical range of the continental, and of the abyssal species, we
have, unfortunately, no data for the Indian Ocean, and we must therefore limit our com-
parisons of geographical distributions entirely to the littoral faunae thus far recognised
in the Atlantic and Pacific.

Examining in the first place the continental species by themselves, we find a far greater
proportion of representative species among the Atlantic and Pacific continental species
than we find when comparing the corresponding littoral faunae; and if we take, as perhaj)s
belonging to the continental species, a few species of which only a few or single siDecimens
were collected, the representative character of the Atlantic and Pacific continental
geographical fauna; is cj^uite stiiking.

We find both in the Atlantic and iu the Pacific species of Poroeidaris, Salenia,
Podocidaris, Ccelopleurus, Aspidodiadema, Asthenosonia, Phormosoma, Trigonocidaris,
Echinus, Paleopneustes, Rhinohrissus, Agassizia, Schizaster, and Periaster.

Such species as Goniocidaris may belong perhaps to the littoral range ; we have left
thus far among the continental species characteristic of the Atlantic only a small
number of genera, Temnechhms, Hemipyedina, Neolampus, Conochjpus, and as
characteristic of the Pacific continental ranges Micropyga, Catopygus, Nacopatagus, and
Moiropsls. A condition of things totally unlike that is found when comparing the same
districts with regard to the occurrence of the same genera. That is, among 22 genera of
the continental range 14 are represented both in the Atlantic and Pacific, while there
are thus far four clistintly Pacific genera, and as many Atlantic ones, while of the littoral
faunae, only six are characteristic of the Atlantic, 31 genera as common to both, and 36
are thus peculiar to the Pacific.

When we examine the abyssal species, leaving out of consideration the few which
may perhaps belong to the continental range, of which we have not sufiicient data, such
as Podocidaris, Aspidodiadema, Prionechinus, Cottaldia, Pygaster, and Linopneustes,
we find as common to the Atlantic and Pacific the following genera : — Asthenosoma,

EEPORT ON THE ECHIXOIDEA. 247

Phormosoma, Pourtalesia, Pcdceotropus, Homolampas, Hemiaster, Aceste, A'erope,
Cystechinus, and Urechimis; while we find as eminently characteristic of the Southern
Ocean such strange forms of Pourtalesise as Spatagocystis, Echinocrepis, and Genico-
patagus, which may hereafter be found to extend north into both the Atlantic and Pacific,
if we can judge of the extension of the few species of Pourtalesia, Cystechinus, and
Urechinus into the Atlantic and Pacific from their numerous representatives in the
Southern and Antarctic Oceans ; while thus far as strictly Pacific we have only of the
abyssal species Cionobnssus and Argopatagus, and as strictly Atlantic only Calymne,
and perhaps Pygaster, showing from the bathymetrical range that the abyssal species proper
are few in number, are mainly limited to the Southern Ocean, and extend northward both
into the Atlantic and Pacific realms. That the continental species form no such restricted
littoral faunae as are characteristic of the species, having a narrow bathymetrical range,
but that we have as it were an Atlantic and a Pacific realm, which we are perhaps
justified in considering as off-shoots of the great separation w^hich took place, dividing the
great Southern Ocean when it extended uninterruptedly over the whole Southern Hemis-
phere, or at any rate when South America separated the Atlantic from the Pacific only
as a large island or an archipelago, geographical off-shoots of a time when the genera
characteristic of these two great realms may have been represented in the Atlantic and
Pacific Gulfs (to use Thomson's happy terminology) by identical species ; these now, in our
present epoch, bear to each other much the same relationship which the littoral species on
the two sides of the isthmus bear to one another, and measure as in that case the degree
of change or time which has elapsed since the separation has taken place, resulting in a
condition of things making a separation of the deep-sea forms into an Atlantic and a Pacific
continental realm possible. Just as the subsequent farther isolation of districts in the
Atlantic and Pacific may gradually have brought about a centralisation into littoral faunae
such as are generally recognised; while the species which have a great bathymetrical or
geographical range are those which have escaped the influence of these changes, some of
them which extend from the littoral to the aliyssal going back to the time when the
Atlantic and Pacific realms were not yet isolated, and thus explaining the existence of
the same species at distant geographical points, while others extending only to the
continental range from the littoral, recall the time when the Atlantic and Pacific realms
were already separated, and when the species of the continental range appeared as
representative species in the Atlantic and Pacific ; while those species which extend from
the continental to the abyssal have never been subject to the influences which have gone
to form either the continental ranges alone, or the littoral range. The genera wliich have
this great bathymetrical range are the following : I have marked witli T. genera which
occur in the Tertiary, and with C. those which occur in the Cretaceous.

248

THE VOYAGE OF H.M.S. CHALLENGER.

L.+ Meoma, T.
L.++ Schizaster, T.
L.+ Metalia, T.
C."^ Neolampas.
L. "*""*" Briiisopsis.
L.++ Hemiaster, C.
L."*""*" Echinocardium, 1
L.+ Spatangus, T.
L.++ Maretia, T.
L."*" Echinolampas, T.
L.+ Mellita, recent.
L."*" Peronella, recent.
L.+ Clyp)easter, T.
L."^ Echinanthus, T.
L. "*"■*" Echmocyamus, C.
L.++ Fibularia, C.
L.+ Toxopneiistes, T.

L.+ Hipponoc, T.

L.++ Echinus, C.

L.+ Salmacis, T.

C.""" Temnechinus, C

L.+ Temnopleurus, T.

L.+ SphcBrecliinus,

L."*" Echinometra, T.

C."*" Phormosoma (Echinothuri-

d£e, C).
C."*" Micropyga.
C.+ Cielopleurus, T. {Magnosia,

C).
L.+ Arhacia, T.
C."*" Salenia, C.
L.++ Gonioeidaris, recent.
L.+ aVZarts, T.
L. "'■"*' Dorocidaris, C.

It is interesting to note that all the genera which have the greatest bathymetrical
range, which extend from the littoral to the abyssal region, are at the same time genera
which date back to the Cretaceous, while those which have a somewhat more limited
range date back to the Tertiaries, and those genera which happen to extend only slightly
beyond the strictly littoral range date back only to the more recent Tertiary periods. Of
com-se the difficulty of tracing the connection between the species of the present epoch,
which may have ranged in the Tertiary, in shallow seas, or in deeper water is very great,
and the mixture thus created in the littoral fauna of the present clay it is practically
impossible to disentangle at present, if we take into account the impossibility of
determining what are strictly deep-sea genera at the present day on account of the great
bathymetrical range of many genera, and the possibility that what may be to-day a
littoral species may have been a deep-water genus in older geological times or vice versa.

The extremes of temperature which we find in the sea at different depths character-
ising the different l.)athymetrical regions we have recognised are much smaller than the
extremes of temperature which characterise our terrestrial fauna and flora. We have
no such extremes as are distinguished on land between a tropical and an arctic fauna
or between a fauna in the tropics near the level of the sea and one near the lower limit
of perpetual snow. Yet in the one case the difference in pressure of the surrounding
medium is small, say at the outside there is not a greater difference than two-thirds,
while between the abyssal regions and the littoral regions we have no such extreme of
temperatures, but extremes of pressure represented by a ratio of one to three hundred

REPORT ON THE ECHINOIDEA. 249

at the average depth of the Atlantic and Pacific basins, which does not seem to have
practically any influence whatever on the distriljution of species ; whUe the slight range
of temperature which affects the upper layers of the waters so as to form a littoral faima
within the limits where we have the greatest possible differences between the extremes
of heat and cold, due to the daily changes of the temperature, and a continental fauna
extending to those depths which we may assume are affected by the slower action of the
heat of the sun at different seasons ; while at last we find the abyssal regions in which
the changes of temperature can be considered as null and in which there is a most
remarkable uniformity of temperature though the conditions of pressure at the extremes
of depths to which the species belonging to this abyssal fauna range are immensely
greater than corresponding extremes due to the difi"erence of atmospheric pressure at
different levels on the surface of the earth.

If we examine the physical conditions which prevail within the 100 fathom line,
within the continental limits, and within the oceanic limits, we, of course, at first would
be inclined to look upon the great differences of pressure as the important element in the
limitation of faunas. The fact, however, that one and the same species so readUy adapts
itself to the enormous diflferences of pressure occurring in the oceanic, continental, and
even littoral districts would seem to show that this element is not an all-important one.
It is among the littoral districts that we find the greatest diversity of faunae, and these
littoral districts mainly differ in their temperature, but it is not the greatest amount of
heat which apparently forms the limits of these districts.

They are separated by Hnes of lowest temperatures. Thus we find an arctic and
boreal district, a tempei'ate and a tropical district in which the extremes of temperature
range within comparatively narrow limits. A similar condition of things exists within
the littoral, continental, and abyssal districts ; they represent the depths at which as a
general rule certain well marked conditions of temperature exist, regulating as they do
for the littoral districts the principal faunistic features of the bathymetrical districts.
The littoral where the changes of temperature are greatly affected by the action of the
sun ; the continental extending from this limit into regions where we find the tempera-
ture gradually diminishing till we come to the abyssal or oceanic depths at which we
have practically a uniform temperature.

With the exception of the abyssal species found in the Southern Ocean near the
Antarctic circle, none of the species of Echinids seem to extend to very great distances from
the continental ranges. This agrees well with my own observations in the "Blake," where
I found that at even a comparatively short distance from the land there was a marked dimi-
nution in the number of species, and also in the number of specimens collected. The
greatest distances from any land or banks of moderate depths at which Echinids have
been collected are off Tristan da Cunha, at Stations 133, 334, 335 ; at Stations 153, 156,
157, 158 in the Southern Ocean, south of the Heard Islands, which, however, may not

(ZOOL. CHALL. EXP. — PART IX. — 1881.) I 32

250

THE VOYAGE OF H.M.S. CHALLENGER.

be very far from the Antarctic continent ; at Station 70 to the westward of the Azores ;
at Stations 296 and 302 to the westward of the southern coast of Chili ; and at
Station 106 to the east of the IsLand of St Paul. In no case is the distance g-reater than
six hundred miles, but it is difficult with this range from shores to draw the outline of
any land in such a way that the great continental masses will not be connected in several
places, or at any rate will only leave comparatively restricted oceanic areas which would
not fall within the lines. Such an area would be found in the North Atlantic in the
rectangle formed Ijy the Bermudas, Sombrero, Cape Verde Islands, and the Azores. A
smaller area in the South Atlantic, limited by the eastern coast of South America, Ascen-
sion, St Helena, Tristan da Cunha, and the Falkland Islands ; another in the central
part of the Indian Ocean ; a smaller area to the south-west of Australia towards the
Antarctic circle ; and two areas in the Pacific, one extending from north-west to south-
east from the 20° of northern latitude, and about the same latitude south, and one ex-
tending from east to west, south of latitude 30° S. towards the Antarctic circle — and
an elongated area in the northern part of the Pacific which may perhaps be considered
only as an area of the fii'st-mentioued district.

In the accompanjdng geographical lists the species collected Ijy the Challenger and
already known from the same districts are marked x ; those previously known but found in
the district for the first time by the Challenger are marked ©, and the species discovered
by the Challenger are marked *.

Northern Chili — Rio La Plata.

Range in Dejitli and Principal Localities.

DESMOSTICHA, Hajckel.

CiDAEID/B, Miill.

GoNiociDARiD^, Hfeckel.
Goniocidaris, Des.
X G. canaliculata, A. Ag.,

Abbaciad^, Gray.

Ariacia, Gray.

X A. diifresnii, Gray,

xA. nigra, A. Ag., ....
X A. spatuligera, A. Ag., .

DIADEMATID.5E, Peters.

Aspidodiadema, A. A;,'.
*A. microtuberculatum, A. Ag.,

Falkland Islands, 5-10 fathoms; Straits of Magellan; xStation 313, 55
fathoms; xStation 315, 6-12 fathoms (Southern Ocean).

(East Patagonia, 44 fathoms B. ; Chili; x Station 304, 45 fathoms;
( xStation 308, 175 fathoms (Southern Ocean).

Cape Horn ; Chili (Philippines).

Chili.

( xStation 298, 2225 fathoms; xStation 299, 2160 fathoms (Atlantic;
j Southern Ocean).

REPORT ON THE ECHINOIDEA.

251

EcHiNOTHDRiD,«, Wy. Thom.

Phorriwso'm.a, Wy. Thorn.
*P. asterias, A. Ag.,
*P. hoplacantha, Wy. Thom., .

ECHIN01IETRAD.E, Gray.

C'olobocentrotus, Br.
C. atraUis, Br.,

Strongyloccntrotus, Br.
S. aft»s, A. Ag., .
X S. cjihhosus, A. Ag.,

EcHlNlD^, Agass.

TeiplechiniDjE, a. Ag.

Echinus, Bond. (Linn.).
*£. horridus, A. Ag.,

X E. magellanicus, Phil., .

X E. nmrriaritaceus, Lanik.,
07J. norvcrjicus, Diib. o. Kor., .

PETALOSTICHA, Hfeckel.
SpatangidjE, Agass.

POURTALESLE, A. Ag.
Pourtalesia, A. Ag.
*P. carinata, A. Ag.,
*P. ceratopyga, A. Ag., .

Urechinus, A. Ag.
*?7. naresianus, A, Ag., .

Cystcchinus, A. Ag.
*C'. vesica, A. Ag., .

*C'. wyvillii, A. Ag.,

Spatanoina, Gray.

Nacopatagus, A. Ag.
iV^. gracilis, A. Ag.,

Brissina, Gray.
Hemiaster, Des.
X H. cavernosus, A. Ag., .

Tripylus, Phil.

y. excavatus, Phil.,

Agassizia, Val.

.4. exceiitrica, A. Ag.,
.(4. scrohicidata, Val.,

Schizaster, Agass.

*.S. moseleyi, A. Ag.,

iS. philippii, A. Ag.,

Range m Depth aud Principal Localities.

.^Station 299, 2160 fathoms (Southern Ocean).
xStation 300, 1375 fathoms (Southern Ocean).

Chili (African ; Indian ; Pacific).

Straits of Magellan ; Chili (Philippines).

Straits of Magellan ; Chili ; x Station 304, 45 fathoms.

X Station 308, 175 fathoms.

Straits of Magellan, 57 fathoms ; ChiU ; East Patagonia, 44 fathoms B. ;
X Station 315, 5-12 fathoms ; x Station 304, 45 fathoms ; x Station 308,
175 fathoms; xgfation 312, 10-15 fathoms (Southern Ocean).

Straits of Magellan; Chili; x Station 308, 175 fathoms; x Station 311,
245 fathoms (Southern Ocean).

X Station 308, 175 fathoms (Atlantic; Japan).

X Station 298, 2225 fathoms (Antarctic).

xStation 298, 2225 fathom.s; xStation 299, 2160 fathoms (Antarctic).

X Station 302, 1450 fathoms (Antarctic, Caribbean).

XStation 298, 2225 fathoms; xStation 299, 2160 fathoms (Antarctic).
XStation 296, 1825 fathoms; xStation 299, 2160 fathoms; xgtation 300,
1375 fathoms (Antarctic).

Juan Fernandez, 65 fathoms B.

( East Patagonia, 44-55 fathoms B. ; Chib' ; xStation 310, 400 fathoms;
( Off La Plata, 50 fathoms B. (Southern Ocean).

East Patagonia, 44 fathoms B. ; Cliili.

Off La Plata, 44 fathoms B. (Caribbean).
Juau Fernandez, 220 fathoms B. (Peruvian).

xStation 305, 120 fathoms; xStation 307, 147 fathoms; xStation 309,
40-140 fathoms; xStation 310, 400 fathoms; xStation 311, 245
fathoms (Southern Ocean).

La Plata ; Cliili.

252

THE VOYAGE OF H.M.S. CHALLENGER.

The following species having a continental and abyssal range find their way into the
South American district : —

Aspidodiadema microtubercidatum,

Atlantic and Pacific.
Phormosoma asterias, Southern Ocean.
Phormosoma hoplacantha „

Urechimis naresianus

Cystechinus vesica, Southern Ocean.
Cystechinus ivyvillii „

Pourtcdesia carinata „

Pourtcdesia ceratopyga ,,
Schizaster inoseleyi „

Echinus norvegicus is the only European boreal species not hitherto found at the
southern extremity of South America collected by the Challenger with a new species of
Echinus [E. horridus), all the other species are evidently only northern extensions of
the Southern Ocean abyssal species. Schizaster moseleyi is also a more shallow Southern
Ocean species. The South American district seems to be like that of the Cape of Good
Hope ; it has no species peculiar to itself, and is the meeting ground of the southern
limits of the Brazils, Virginia, of the Atlantic, of the Southern Ocean, and of the
southern extremity of the Peru- Chili districts.

Southern Brazil — Eastern Virginia.

Range in Depth and Princii"tal Localities.

DESMOSTICHA, Heeckel.
C1DARID.E, Miill.
GoNiociDARiDiE, Hfeckel.
Cidaris, Kl.

X C. tribulovles, Bl., ....

Dorocidaris, A. Ag.
D. bartldti, A. Ag.,
D. blakii, A. Ag., ....

X D. papillata, A. Ag.,

Porocidaris, Des.

P. sharreri, A. Ag.,

SalenidjE, Agass.

Saknia, Gray.

S. goesiana, Lov., ....
*S. hastigera, A. Ag.,
S. pattersonii, A. Ag., .

X S. varispina, A. Ag.,

( South Carolina ; West Indies, 20-250 fathoms B. ; Florida,- Gulf Stream,
< 116 fathoms; Tortugas, 30-36 fathoms; Rio Janeiro; >< Fernando
( Noronha; xBahia, 7-20 fathoms (North Atlantic).

Caribbean Islands, 76-398 fathoms B.

Caribbean Islands, 158^50 fathoms B.
(Florida, GuK Stream, 40-195 fathoms B. ; Caribbean Islands, L.
{ -874 fathoms B. ; xStation 24, 390 fathoms; xBt Paul Rocks, 70-80
( fathoms; xStation 320, 600 fathoms (Atlantic; Pacific).

Caribbean Islands, 123-351 fathoms B.

Caribbean Islands, 180 fathoms J.

xStation 106, 1850 fathoms; xStation 335, 1425 fathoms (Pacific).

Caribbean, 82-450 fathoms B.
( Florida, Gulf Stream, 135 fathoms; Caribbean Islands, 120-1200
} fathoms B. ; xStation 23, 450 fathoms; xStation 24, 390 fathonw
( (Atlantic).

REPORT ON THE ECHINOIDEA.

253

Arbaciad^, Gray.

Arbacia, Gray.

A. punetulata, Gray,
A. pustulosa, Gray,

Podocidaris, A. Ag.
X P. sculpta, A. Ag., .
P. scutata, A. Ag.,

Codopleums, Agass.

C. floridanus, A. Ag.,

D1ADEIIATID.E, Petere.
Diadema, Schynv.

D. setosum, Gray, .

Aqndodiadema, A Ag.,

*A. microtiibercukitum, A. Ag.,

A. antillarum, A. Ag., .
A. jacobyi, A. Ag.,

EcHiNOiHURiD^, Wy. Thorn.
Asthenosoma, Grube.
A. hystrix, A. Ag.,
A. reynoldsii, A. Ag.,

Phormosoma, Wy. Thorn.
P. sigsbei, A. Ag., .
P. petersii, A. Ag.,

EcHiNOMETKAD;E, Gray.
Echinometra, Kondel. (Breyn.)
X E. subangularis, Desml.,
E. viridis, A. Ag., .

Strongylocentrotus, Br.,
S. drobachicnsis, A. Ag.,
S. gaiinardi, A. Ag.,
S. lividm, Br.,

EcHlNlD^, Agass.
TEMNOPLEURID.E, Des.
Temnechimis, Forbes.

T. maculatus, A. Ag., .

TrigoTWcidaris, A. Ag.
T. alUda, A. Ag., .

Triplechinid^, a. Ag.

Hemipedina, Wright.
H. cnbensis, A. Ag.,

Range in Deptli and Principal Localities.

North Carolina, 7 fathoms ; Florida, GuK Stream, 13-125 fathoms B. ;

Yucatan ; Caribbean, 14-84 fathoms B.
St Thomas ; Eio Janeiro (Atlantic).

Florida, Gulf Stream, 120-315 fathoms; Caribbean, 250-400 fathoms B. ;

X Station 24, 390 fathoms.
Caribbean Island.s, 580 fathoms B.

Florida, GuK Stream, 160 fathoms; Caribbean, 56-1523 fathoms B.

i South Florida; Surinam; Bermudas; Caribbean, 60-291 fathoms B. ;
' Santaren Channel, 40 fathoms (Atlantic ; Pacific).

Caribbean Islands, 860-1400 fathoms B. ; x Station 134, 2025 fathoms;
X Station 122, 356 fathoms (Atlantic; South Pacific).
' Caribbean Islands, 208-1200 fathoms B.
Caribbean Islands, 95-287 fathoms B.

Florida, Gulf Stream, 138 fathoms; Caribbean Islands, 100-1097

fathoms B. (Korth Atlantic).
Caribbean Islands, 180-375 fathoms B.

Caribbean Islands, 12(1-1242 fathoms B.
Caribbean Islands, 399-1234 fathoms B.

South Carolina; Bermudas; Rio Janeiro; Caribbean Islands, 14-250

fathoms B. ; xAscension Island (Atlantic).
Florida, Gulf Stream, 7 fathoms ; Hayti ; West Indies.

South Carolina (Arctic).

BrazQ.

Bahia ; Rio Janeiro (Atlantic).

( Florida, Gulf Stream, 10-147 fathoms; Caribbean Islands, 37-229
( fathoms B. (North Atlantic).

( Florida, Gulf Stream, 40-270 fathoms; Caribbean Islands, 24-450
\ fathoms B. (North Atlantic).

Florida, GuK Stream, 138-270 fathoms B.

254

THE VOYAGE OF H.M.S. CHALLENGER.

Echinus, Koud. (Linn.).
0J5. acutus, Laiiik., .
®£. clegans, Diib. o. Kor.,

E. gracilis, A. Ag.,

E. norvegicus, Diib. o. Kor., .
E. wallisii, A. Ag.,

Toxopnewstes, Agass.
X T. variegatus, A. Ag., .

Hippono'e, Gray.

H. esculenta, A. Ag.,

Clypeastrid^, Agass.
EchinoconiDjE, D'Orb.

Pygaster, Agass.

P. relictus, Lov., .

EucLTPEASTRiD^, Hseckel.

FlBULARiNA, Gray.
Echinocyamus, Van Pheliw.
X E. pusillus, Gray, .

ECHINANTHID^, A. Ag.

Clypeaster, Lamk.
X C. subdepi-essits, Agass., .

Echinanthus, Breyn.
E. rosacew. Gray, .

SCUTELLIDiE, AgaSS.

Mellita, Kl.
X M. sexforis, A. Ag.,
M. testudinata, Kl.,

Encope, Agass.
X E. enwrginata, Agass., .

E. michelini, Agass.,
PETALOSTICHA, H<Eckel.

C'ASSIDTJLIDiE, AgaSS.

EcHiNONiD^, Agass.

Echinonhis, Van Phelps.
E. semilunaris, Lamk., .

NucLEOLiDiE, Agass.

Neolampas, A. Ag.

N. rostellata, A. Ag.,

Range in Depth .and Principal Localities.

X Station 343, 42.5 fathoms (Atlantic; Pacific).

X Tristan da Cunha, 1100 fatlioms (Atlantic; Pacific).

Florida, GuK Stream, 100-200 fathoms; St Thomas; Caribbean, 175

fathoms B.
Florida, Gulf Stream, 19.5 fathoms ; Atlantic Coast of U. S., 1242

fathoms B. ; (Atlantic ; Japan).
Atlantic Coast of U. S. (South and Middle States), 267-1047 fathoms B.

North Carolina, 7 fathoms ; Bermudas ; Florida, Gulf Stream, 5-34
fathoms; Caribbean Islands, 14-242 fathoms B.

i South Florida; Bermudas; Surinam; Caribbean Islands, 14-451
fathoms B.

Virgin Islands, 180 fathoms J.

Florida, GuK Stream, 5-325 fathoms ; Caribbean Islands, 98-805 B. ;
xStation 122. Off Barra Granda (no depth on label), (North Atlantic),

South Carolina; Brazil; Florida, Gulf Stream, 11-40 fathoms; Florida;
Caribbean Islands, 36-248 fathoms B. (North Atlantic).

South Carolina; West Indies; Caribbean Islands, 14-118 fathoms B.

South Carolina ; Bermudas ; West Indies ; Florida, Gulf Stream, 4-270

fathoms; xBahia.
East Virginia ; West Indies ; Rio Janeiro.

South Carolina ; West Indies ; Florida, GuK Stream, 7 fathoms ; Eio

Janeii'o ; x Bahia, 20-70 fathoms.
Alabama ; West Florida ; Honduras ; Yucatan ; Florida, GuK Stream,

5-6 fathoms; Caribbean Islands, 14 fathoms B.

Bermudas ; Florida Keys ; Caribbean Islands, 80-805 fathoms B.

Florida, Gulf Stream, 112-125 fathoms; Caribbean Islands, 100-229
fathoms B. (North Atlantic).

REPORT ON THE ECHINOIDEA.

255

Echinolampas, Gray.

E. depressa, Gray, .

Gonoclypus, Agass.
G. sigshii, A. Ag., .

Rhijnchoptygiis, D'Orb.

B. caribcearum, Liitk., .

Spatangid/e, Agass.

PourtalesIjB, A. Ag.
Pourtalesia, A. Ag.
P. rmranda, A. Ag.,

Urechinus, A. Ag.

U. naresianiis, A. Ag., .

Cystechinus, A. Ag.
*C clypeatm, A. Ag.,

Ananchttid^, AIIj. Gras.

Palwotropus, Lov.
P. josephinw, Lov.,
P. thomsoni, A. Ag.,

Homolampas, A. Ag.
X H. fragilis, A. A'^.,

Paleopneustes, A. Ag.
P. cristatus, A. Ag.,

P. hystrix, A. Ag.,

Linopneustes, A. Ag.

L. longispinus, A. Ag., .

Spatangina, Gray.

Spatangus, Kl.

0.S'. purpureus, Leske.,

Eclmiocardium, Gray.
E. cordatum, Gray,
E. flavescens, A. Ag.,
E. pennatifidum, Norm.,

Brissina, Gray.

Hcmiaster, Des.

H. expergitiis, Lov.,

*H. xonatus, A. Ag.,

H. mentxii, A. Ag.,

Rhinohrissus, A. Ag.

li. micrasteroides, A. Ag.,

Brisaopsis, Agass.
B. lyrifera, Agass.,

Aceste, Wy. Tliom.
*A. lelkdifcra, Wy. Thorn., .

Range in Depth and Principal Localities.

Florida, Gulf Stream, 35-120 fathoms; CariblK-aii Islands, 82-160
fathoms B.

Straits of Florida ; Yucatan, 84-450 fathoms B.
Florida, Gulf Stream ; West Indies, 106 fatlioms B.

( Florida, Gulf Stream, .349 fathoms ; Caribbean Islands, 242-576 fathoms B.
\ (North Atlantic).

Caribbean Islands, 422 fathoms B (Southern Ocean, Atlantic).

( xStation 133, 1900 fathoms ; ^Station 334, 1915 fathoms (South Atlantic ;
( Pacific).

Caribbean Islands, 177-243 fathoms B. (North Atlantic).
Atlantic Coast, U. S. (Soutli Coast), 233 fathoms B.

( Floriila, Gulf Stream, 320-368 fathoms ; Cariljljean Islands, 320-1920
I fathoms B. ; xStation 122, 400 fathoms (North Atlantic).

Straits of Florida ; Caribbean Islands, 56-450 fathoms B.
Caribbean Islands, 21-208 fathoms B.

Caribbean Islands, 28-373 fathoms B.

xBermudas, 100 fathoms; Caribbean Islands, 82-373 fathoms B. (North
Atlantic).

North Carolina; Florida Reef, 79 fathoms; Bahia (North Atlantic).
South Carolina ; Florida, Gulf Stream, 85-138 fathoms ; Bahia (Atlantic).
Florida, Gulf Stream, 79-121 fathoms (North Atlantic).

Caribbean Islands, 485 fathoms B. J. (North Atlantic).
xStation 126, 750 fathoms (North Atlantic).
Caribbean Islands, 170-576 fathoms B.

Caribbean Islands, 175-242 fathoms B.

( Florida, Gulf Stream, 53-128 fathoms; Caribbean Islands, 118-242
i fathoms B. (Atlantic).

XStation 323, 1900 fathoms (Atlantic; Pacific).

256

THE VOYAGE OF H.M.S. CHALLENGER.

Range iu Depth and Priucipal Localities.

Agassizia, Val.

A. excentriai', A. Ag.,

Brissiis, Kl.
*B. dcnnesi, A. Ag.,

B. imicolor, KL, ....

Metalia, Gray.
X M. pectoralis, A. Ag.,

Meoma, Gray.

M. ventricosa, Liitk.,

Schizaster, Agass.

S. fragilis, Agass., ....

S. orbignyanits, A. Ag., .

Periaster, D'Orb.

P. limicola, A. Ag.,

Moira, A. Ag.

M. atropos, A. Ag.,

Florida, Gulf Stream, 35-45 fathoms ; Caribbean, 86-287 fatlioms B.

X Station 122, 400 fathoms (Nortli Atlantic).

South Florida, 17-128 fathoms ; West Indies ; Bermudas (North Atlantic).

West Florida ; West Indies; Bahia; Florida Gialf Stream, 115 fathoms.

( Florida; Honduras; Floriila, Gulf Stream, 85-115 fathoms; Caribbean
( Islands, 37-242 fathoms B.

j Atlantic Coast of U. S. ; Florida, Gulf Stream ; Caribbean Islands,
( 71-950 fathoms B. (Atlantic).
Caribbean Island.?, 92-1507 fathoms B.

Gulf of Mexico, 118 fathoms B. (Pacific).

( North Carolina ; Florida ; West Indies ; Texas ; Florida Gulf Stream,
( 80 fathoms.

Oil comparing the species collected by the Challenger in this district, we find that the
Challenger traced the existence oi Echinus acutus, Echinus elegans, and Echinus norvegicus
to the eastward of Cape Cod, and also of Echinus acutus as far south as Ascension, and
of Echinus elegans to Tristan da Cunha ; Cidaris t-nbuloides to Fernando Noronha, and
Dorocidaris 2)«2^iU(ita, to St Paul Rocks and Buenos Ap'es. Scdenia varispina was also
found as far as Ascension, and the Northern part of Brazil. Echinocyamus j^usiUus
Metalia pectoralis and Homolampas fragilis are also found ofi" the latter shores.

Schizaster fragilis has also been found by the United States Fish Commission iu the
Gulf of Maine ; it was found by the Challenger off the Nova Scotia coast, and wth the
exception of Pourtcdesia p)hicde no species from the Southern Ocean find then- way north-
ward in the Atlantic. There are found on the western side of the Atlantic of the abyssal
species Aspidodiadema microtubercidatum, Urechinus naresianus, Cystechinus clypeatus,
Aceste hellidifera, and Hemiaster zonatus, while Brissiis damesi is thus far only known
from Northern Brazd and the Azores. On the eastern side are found Aceste hellidifera,
Hemiaster zonatus, Phormosoma tiranus, Asthenosoma fenestratum, Aspidodiadema
tonsuni, Ccdymne relicta, Aerope rostrata, Porocidaris purpurata ; Salenia hastigera,
and Scdenia varispina ; Salenia varispina, Brissus damesia, Hemiaster zonatus,
Pourtcdesia jeffreysi, Neolampas rostrata, Temncchinus macidatus, and Trigonocidaris
cdhida being thus far the only strictly Atlantic species. Spatangus purpureus was
found by the Challenger at the Azores and Bermudas, and I have dredged it from the
Caribbean Seas, while we have along this district, as might be expected, quite a weU-
marked continental fauna agreeing fairly mth the associated littoral fauna in geographical
range, but, as has been stated, made up of representative species for the greater part.

REPORT ON THE ECHINOIDEA.

257

New Jersey — Iceland.

Eange in Depth and Principal Localities.

DESMOSTICHA, HcBckel.
ARBACiADiE, Gray.

Arbacia, Gray.

A. punctulata, Gray,

EcHiNOMETRAD^, Gray.
Strcmgylocentrotus, Br.
X S. drcibachiensis, A. Ag.,

E c H I N I D .E, Agass.

Triplechinid^, a. Ag.

Echimis, Eond. (Linn.)
@E. acutus, Lamk., .
0S. elegans, Diil). o. Kor.,
E. escuhntus, Linn.,

QE. norvegicus, DUb. o. Kor., .

E. wallisii, A. Ag.,
Toxopneustes, Agass.

T. variegatus, A. Ag., .

Clypeastrid^, Agass.

EucLTPEASTRiD^, Hajckel.

FiBDLARiNA, Gray.

Echinocyamns, Van Phelps.
E. pusilbts. Gray, .

ScuTELLiD^, Agass.

Echinarachniics, Leske.
E. pariiw, Gray, .

Mellita, Kl.

M. tesludinata, Kl.,

Petalosticha, Hajckel.
Spatangid/e, Agaas.

PODRTALESI^, A. Ag.

Pourtalesia, A. Ag.

P. phiale, Wy. Thorn., .

Urechinus, A. Ag.

U. naresianns, A. Ag., .

Brissina, Gray.

Brissopsis, Agass.

B. hjrifera, Agass.,
Aerope, Wy. Thoin.

■*A. rostrata, Wy. Thorn.,
Schizaster, Agass.

X S. fmgilis, Agass., .

Cape Cod ; Long Island Sound, 20 fathoms (Carihhean).

J Iceland ; Greenland, 410 fathoms Val. ; New England, 100 fathoms ; New
/ Jersey; xLahave Bank, 51 fathoms; x Station 49, 83 fathoms (Arctic).

X Station 46, 1350 fathoms (Atlantic; Pacific).

^Station 46, 1350 fathoms (Atlantic; Pacific).

Iceland (East Atlantic),
j Oft' New Jersey, 1242 fathoms, B. ; xStation 46, 1350 fathoms; xStation
( 47, 1340 fathoms (Atlantic ; Japan).

East Coast U.S. (Middle States), 304-524 fathoms B.

New Jersey (Caribbean).

Iceland (North Atlantic).

( Lal^rador, 2-15 fathoms; New Jersey; Off George's Bank, 306 fathoms,
I B. ; Oft' North West Atlantic Coast; North America, 40 fathoms
I (Arctic ; Indian).

New Jersey (Caribbean).

X North Atlantic, 1T85 fathoms (Antarctic; Southern Ocean).

1242 fathoms B, Atlantic Coast of U.S. (Middle States) Southern Ocean,
Atlantic.

Greenland (Atlantic).

Davis Straits, 1750 fathoms Val. (Atlantic ; Pacific).

Gulf of St Lawrence, 250 fathoms ; Greenland, 410 fathoms Val. ; off R. I.
and New Jersey, 71-306 fathoms, B. ; XStation 49, 83 fathoms
(Atlantic).

(ZOOL. CHALL. EXP. PART IX. 1881.)

I 33

258

THE VOYAGE OF H.M.S. CHALLENGER.

Northern Shores of Siberia — West Coast of France.

DESMOSTICHA, Hseckel.
C I D A R I D ^, Miill.
GoNiociDARlD^, Hseckel.
Darocidaris, A. Ag.

D. papillata, A. Ag.,

Porocidaris, Des.

P. purpurata, Wy. Thorn.,

Arbaciad^, Gray.

Arhacia, Gray.

A. piistulosa, Gray,

ECHINOTHURID.E, Wy. Thom.
Asthenosoma, Grube.
A. hystrix, A. Ag.,
A. fenestratum, Wy. Thorn., .

Phormosoma, Wy. Thom.
P. placenta, Wy. Thom.,

EcHrNOMETEAD^, Gray.
Strongylocentrotus, Br.

S. drobaddensis, A. Ag.,
S. lividus, Br.,

Sptuerechiniis, Des.

S. granularis, A. Ag.,

Triplechinidte, a. Ag.
Echinus, Eond. (Linu.).

E. acutus, Lamk., .

E. eleyans, Diib. o. Kor.,

E. esculentus, Linn.,

E. microstoma, Wy. Thom., .
E. miliaris, Miill.,

E. norvegicus, Diib. o. Kor., .

CLYPEASTRID^, Agass.
Edcltpeastrid^, Hoeckel.
FiBULARiNA, Gray.
Echinocyamtis, Van Phelps.
E. 2ntsillus, Gray, .

Range in Depth and Principal Localities.

West Coast of Norway, 80-100 fathoms ; North Sea, 200 fathoms ; Faroe
Islands— Gibraltar, 100-1000 fathoms P. ; Cape Wrath, 280 fathoms
P. ; South Ireland, 80-90 fathoms (Atlantic ; Pacific).

Shetland Islands ; Faroe Islands ; Butt of the Lewes, 542 fathoms P.

West Coast of France (Atlantic).

Slietland Islands ; Rockall, 547 fathoms ; Butt of the Lewes, 445

fathoms P. ; Off Vigo (Nortli Atlantic).
Rockall, 445 (!) fathoms P. (East Atlantic).

J West Scotland and Ireland, 500-800 fathoms ; Butt of the Lewes, 500
( fathoms P. (East Atlantic).

British Seas ; Spitzbergen ; Lofoten Islands, 60 fathoms ; North Coast of

Siberia ; North Sea, 100 fathoms (Arctic).
West Coast of France ; British Seas (Atlantic).

West Coast of France (East Atlantic).

( West Coast of France ; Irish Sea, 100 fathoms ; West Coast of Norway ;
< Shetland Islands, 150 fathoms; Faroe Islands, 400 fathoms (Atlantic ;
( Pacific).

S South Ireland; West Coast of Norway, 150-250 fathoms; Faroe Islands,
( 400 fathoms ; Valencia, 90 fathoms (Atlantic ; Pacific).
English Channel ; West Coast of Norway, 80 fathoms ; Cape North, 15

fathoms (East Atlantic).
West Scotland and Ireland, 150-^00 fathoms P.
Engli.sh Channel ; West Coast of Norway, 50 fathoms (East Atlantic).
British Seas ; North Sea, 200 fathoms ; Faroe Islands — Shetland Islands,
400 fathoms P. ; Cape Wrath, 300 fathoms P. ; West Coast of Norway,
80-450 fathoms (Atlantic ; Pacific).

5 British Seas ; West Coast Norway, 300 fathoms ; Cape North, 15-25
j fathoms (North Atlantic).

REPORT ON THE ECHINOIDEA.

259

Range in Dei)tli and Principal Localities.

PETALOSTICHA, Hceckel.

Cassidulid^, Agass.

NucLEOLiD^, Agass.

Neolcmvpas, A. Ag.

N. rostellata, A. Ag.,

Spatangid^, Agass.

P0UETALESI.E, A. Ag.

Pourtalesia, A. Ag.

P. jeffreysi, Wy. Thoni.,

P. miratida, A. Ag.,

P. phiale, Wy. Thorn., .

Spatangina, Gray.

Spatangvs, Kl.

S. purpureus, Leske.,

S. raschi, Loven, .

Echinocardium, Gray.
E. cordatum, Gray,

E. flavescens, A. Ag.,

E. pennatifidum, Norm.,

Brissina, Gray.

Brissopsis, Agass.
B. lyrifera, Agass.,

Schizaster, Agass.
<S. fragilis, Agass.,

English Channel, 690 fathoms P. (North Atlantic).

Faroe I.slanrls, Shetland I.^lands, 640 fathoms P.

Shetland and Faroe Islands; EockaU, 1215 fathoms P. (North Atlantic).

Rockall, 1215 fathoms P. (Antarctic; Atlantic).

West Coast of France ; West Coast of Norway, 20-40 fathoms (North

Atlantic).
Shetland and Faroe Islands, 100-300 fathoms P. ; Valencia, 110 fathoms P. ;

West Coast of Norway, 200 fathoms (Atlantic).

English Channel; West Coast of Norway, 15 fathoms (North Atlantic).
English Channel ; West Coast of Norway, 20-30 fathoms ; Cape North, 40

fathoms ; Cape Wrath, 100 fathoms P. (Atlantic).
Shetland Islands (North Atlantic).

South Ireland, 50-2090 fathoms P. ; West Coast Norway (Atlantic).

Shetland— Faroe Islands, 400-500 fathoms P. ; West Coast of Norway,
100-1 50 fathoms (Atlantic).

Portugal — West Coast of Tropical Africa.

Range in Depth and Principal LooaUties.

DESMOSTICHA, Hteckel.

C I D A R I D ^, Miill.

GoNiociDAHiD^, Hieckel.

Cidaris, Kl.
X C. trihuloides, Bl., ....

Dorocidaris, A. Ag.
X D. papillata, A. Ag., .

Porocidaris, Des.

P. purpurata, Wy. Thom., .

Salenid^, Agass.

Saknia, Gray.
*S. hastigera, A. Ag.,

X S. varispina, A. Ag.,

xCape Verde Islands, 15-20 fathoms; Liberia (Atlantic).

( Adriatic; Mediterranean; ^Station VIIL, 620 fathoms; Cape Sagras, 1G5
) fathoms P. (Atlantic ; Pacific).

Cape EspicheL

xOfT Macio, IVOO fathoms ; >:Bay of Biscay ; Coast of Portugal (Pacific).
<) X Station 70, 1675 fathoms; x Stations 73, 78, 1000 fathoms ; xQfifAscen-
( sion, X Station 344, 420 fathoms (Atlantic).

260

THE VOYAGE OF H.M.S. CHALLENGER.

Arbaciad.'E, Gray.

Arbacia, Gray.
X A. pustulosa, Gray,

DlADEMATiD^, Peters.

Diadema, Schynv.
X D. setosum, Gray, .

Gentrostephanus, Pet.
C. longispinu^, Pet.,

Aspidodiadema, A. Ag.
*v4. microtaberc.ulatum, A. Ag.,
*A. tonsum, A. Ag.,

ECHINOTHURID^, Wy. Tliom,

Asthenosovm, Grube

A.fenestratuin,y^j. Thorn., .
A. hystrix, A Ag.,

Phormosoma, Wy. Thorn.
*P. uranus, Wy. Thorn.,

EcHiNOMETRAD.«, Gray.

EcMnometra, Rond. (Breyn.)
X E. subangularis, Desml.,

Strongylocentrotus, Br.
S. livid us, Br.,

Uphmrechimis, Des.
X S. gramdaris, A. Ag., .

ECHINIDiE, Agass.

Temnopleurid^, Des.

Temnechinus, Forbes.
T. maculatus, A. Ag.,

Trigonocidaris, A. Ag.
T. alhida, A. Ag., .

Triplechinid^, a. Ag.

Echinus, Rond. (Linn.)

X E. acutus, Lamk., .

E. elegans, Diib. o. Kor.,

E. melo, Lamk.,

E. microtuberculatus, BL,

CLYPEASTRIDAE, Agass.

EUCLTPEASTEID^, Hajckel.

FiBDLARiNA, Gray.

Echinocyamus, Van Phels.
E. piisillus. Gray, .

Range in Depth and Prmcipal Localities.

Madeira; Azores; Liberia; x St Vincent (Atlantic).

St Vincent ; Canary Islands ; Sicily (Atlantic ; Pacific).

Madeira; Sicily.

xOff Macio, 1700 fathoms (Atlantic ; Southern Ocean).
xOff Macio, 1700 fathoms (Indian ; Pacific).

Bay of Biscay, 445 fathoms P. (.').
Portugal; Off Vigo (Atlantic).

xStation VI., 1525 fathoms; xStation 78, 1000 fathoms (Atlantic).

Cape Verde ; Azores ; Senegal ; x Ascension (Atlantic).
Canary Islands ; Azores ; Sicily (Atlantic).

Cape Verde Islands; Azores; Sicily; xgt Vincent; xStation 75, 450
fathoms.

Josephine Bank, 600 fathoms J. (North Atlantic).
Josephine Bank, 600 fathoms J. (North Atlantic).

j Portugal ; Sicily ; x Ascension, Station 343, 425 fathoms ; Cape Sagras,
( 165 fathoms, P. (Atlantic ; Pacific).

Cape Sagras, 80 fathoms, P. (Atlantic; Pacific).

Cape Verde Islands ; Sicily ; Messina, 35-55 fathoms (East Atlantic).

Cape Verde Islands ; SicUy (East Atlantic).

Madeira ; Azores ; SicOy (North Atlantic).

REPORT ON THE ECHINOIDEA.

261

Range in Depth and Principal Localities.

ECHINANTHID.«, A. Ag.

Clypeaster, Lamk.

C. subdepressiis, A. Ag., .

SOUTELLID^, Aga.ss.

Rotula, Kl.

R. aiyiisti, Kl.,
B. ruminhii, Kl., .

PETALOSTICHA, Haickel.

Cassidulid.*;, Agass.

NucleolidjE, Agass.

Echinolampas, Gray.

E. hdlei, Val., . .

Spatangid^, Agass.

PODRTALE.SI^, A. Ag.

Calymne, Wj. Thorn.
*C. relicta, Wy. Thorn., .

Ananchttid^, Alb. Gras.

Palcnotropus, Lov.
P. josephince, Lov.,

Homolarnpas, A. Ag.
R. fragilis, A. Ag.,

Spatangina, Gray.

Spatangus, Kl.
X S. purpureus, Leske,
S. raschi, Lov.,

Echinocardium, Gray.
E. cordatum, Gray,
E. mediterranewn, Gray,

Brissina, Gray.

Hemiaster, Des.

H. e'jypergitus, Lov.,
*H. zonatus, A. Ag.,

Brissopsis, Agass.

B. lyrifera, Agass.,

Aerope, Wy. Thorn.
*A. rostrata, Wy. Thorn.,

Aceste, Wy. Thorn.
*A. bellidifera, Wy. Thom., .

West Coast of Tropical Africa (North Atlantic).

West Africa ; Liberia.

Cape Verde Lslands ; Porto Praya, 20 fathoms ; Senegal.

Liberia ; Senegal.

xFayal, 2650 fathoms.

Azores, 250 fathoms, J. (Xorth Atlantic).
Josephine Bank, 5-600 fathoms, J. (North Atlantic).

Mediterranean; Adriatic; x Azores, xStation 75, 50-90 fathoms (North

Atlantic).
Azores ; Faroe Islands— Gibraltar, 100-300 fathoms, P. (Atlantic).

Mediterranean (North Atlantic).
Mediterranean ; Sicily ; Messina, 2-20 fathoms.

West Coast of Spain, 485 fathoms, J. (North Atlantic).
>^Station VIIL, 620 fathoms (North Atlantic),

Mediterranean ; Sicily (Atlantic).

xBay of Biscay and Coast of Portugal (Atlantic ; Pacific).

X Station VIIL, 620 fathoms (Atlantic ; Pacific).

262

THE VOYAGE OF H.M.S. CHALLENGER.

Range in Depth and Principal Localities.

Brissus, Kl.
*B. daniesi, A. Ag.,
B. unic'olor, Kl., ....

Mefalia, Gray.

M. (tfricana, A. Ag.,

M. casta, Lud., ....

Schizaster, Agass.

S. canaliferus, Agass., .

X Station 75, 450 fathoms (North Atlantic).
Cape Verde Islands ; Sicily (North Atlantic).

West Coast Tropical Africa.
Capri, 25 fathoms.

Mediterranean, 37 fathoms ; Sicily.

Cape of Good Hope — Natal.

Range in Depth and Principal Localities.

DESMOSTICHA, Hseckel.

ClDARID^, Miill.
G0N10CIDARID.E, Hceckel.

Cidaris, Kl.

C. metukiria, BL, .

PhyUacanthus, Br.

P. baculosa, A. Ag.,
P. duhia, Br.,

Gmiiocidaris, Des.

G. canaliculata, A. Ag.,

ARBAClADiE, Gray.

Arbacia, Gray.
xA. dufresnii, Gray,

DiADEMATiD^, Peters.

DiadeTna, Schynv.

D. setosura. Gray, .

Echinothrix, Pet.

E. desorii, Pet

EcHlNOMETRAD^, Gray.

Echinometra, Rond. (Breyn.)
E. hicunter, Bl., .

Stomopneiistes, Agass.
S. variolaris, A. Ag.,

Echinostrephus, A. Ag.
E. inolare, A. Ag.,

ECHINID*, Agass.

TriplechinidvE, a. Ag.

Echinus, Bond. (Linn.)
X E. angulosus, A. Ag.,

(African-Indian- Pacific).

(Indo-African).
(InJo- African).

(Southern Ocean).

xNightingale Island (Southern Ocean).

(Atlantic ; Pacific).
(African-Indian-Pacific).

Natal (Afiican-Indian-Pacific).

Natal (Indo-African).

Natal (Afiican-Indian-Pacific).

xSimon's Bay, 10-20 fathoms (African-Indian-Southem Ocean).

REPORT ON THE ECHINOIDEA.

263

Clypeastrid^, Agass.

ScUTELLiD^, Agass.

Echinodismis, Breyn.
E. l(evis, A. Ag., .

PETALOSTICHA, Hsckel.
CASSlDULiDiE, Agass.
Ndcleolid^, Agass.
Echinolampas. Gray.
E. oviformis. Gray,

SPATANGID.E, AgaSS.

Spatangina, Gray.

Spafangus, Kl.
0.5. raschi, Loven, .

Lovenia, Des.
X L. elongata, Gray, .

Echinocardium, Gray.
E. australe, Gray, .
0£. fiavescens, A. Ag.,

Range in Depth and Principal Localities.

(Indian ; African).

Brissina, Gray.

0B. lyrifera, Agass.,

ScJtkaster, Agass.
©.S'. fragilis, Agass., .

(Indo-AMcan).

X Station 142, 150 fathoms; xAgiilhas Bank, 100 fathoms (Atlantic).
X Simon's Bay (Indo- African).

Simon's Bay, 12 fathoms (Indian ; Southern Ocean).
xStation 142, 150 fathoms (Atlantic).

xSimon's Bay, 5-18 fathoms; xStation 141,98 fathoms; xStation 142,
150 fathom-s; xAguLhas Bank, 150 fathoms (Atlantic).

XStation 142, 150 fathoms (Atlantic).

Of the Pacific species at the Cape of Good Hope not hitherto recorded from that
locality, the Challenger collected Lovenia elongata; but by far the most interesting
species collected at the Cape by the Challenger were Spatangus raschi, Echinocardium
Jlavescens, Brissopsis lyrifera, and Schizaster fragilis, which thus far, axe found to be
eminently Atlantic sjaecies characteristic of the deeper water, and cropping to the surface
as in the continental range in Eastern North America, Brazil, West Indies, and Western
European seas.

The assemblage of species at the Cape of Good Hope is most peculiar, it is the
meeting of the western boundaries of the African-Indian-Pacific and of the Indo-African,
the southern boundary of the Atlantic, and the northern extremities of the southern
Ocean faunse, and it has no species characteristic of its own in the contiaental or abyssal

264

THE VOYAGE OF H.M.S. CHALLENGER.

SouTHEEN China — Northern Japan.

DESMOSTICHA, Hseckel.

CiDARID-B, Miill.

GoNiociDARiDiE, Hfeckel.
Cidaris, Kl.

C. metularia, Bl., .

Dorocida/ris, A. Ag.
0 T). iiapillata, A. Ag.,

Phylkicantlims, Br.
X P. baciiloea, A. Ag.,

Goniocidaris, Des.
*0. florigem, A. Ag.,

ARBACL4il>.E, Gray.

Podocidaris, A. Ag.
*P. prionigera, A. Ag., ,

Ccelopleurus, Agass.
00. maillardi, A A%.,

D1ADEMATID.S;, Peters,

Diadenia, Schynv.
D. setosum, Gray, .

Micro}nj(ia, A. Ag.
*Af. microtuberculatum, A. Ag.,

ECHINOTHUBID.E, Wy. Thorn.

AsthenosovM, Grube
*A. gracite, A. Ag.,
*A. tcssdlatum, A. Ag., .
A. varium, Grube,

Phormosoma, Wy. Tlioin.

*P. bursaria, A. Ag.,

*P. hoplacautha, Wy. Thorn., .
*P. limdentum, A. Ag., .
*P. ienwc, A. Ag., .

EcHiNOMETRAP^, Gray.

Echinometra, Rond. (Breyn.)
E. lucunter, BL, .

Strongylocentrotus, Br.
S. depressus, A. Ag.,
S. intermedius, A. Ag., .
S. niidns, A. Ag., .
S. tuberctdatiis, Br.,

Sphaii-echinus, Des.

S. pulcherrimus, A. Ag.,

Range in Depth and Principal Localities.

( South diina, 40 fathoms ; West Shores Phnii>pmes (African-Indlaii-
i Pacific).

X Station 204, 100-115 fathoms (Athmtic).

xStation 201, 82-102 fathoms; Philippines (Indo- African).

xStation 204, 100-115 fathoms (Pacific).

XStation 205, 1050 fathoms (Pacific).

xStation 201, 82-102 fathoms; Mauritius (Indo- African).

Ousima ; Hong Kong (Atlantic ; Pacific).
xStation 204, 100-115 fathoms (Pacific).

xStation 200, 255 fathoms (Pacific).
XStation 204, lUO-115 fathoms.
China.

j xStation 200, 255 fathoms; xgtation 205, 1050 fathoms; xStation 232,
} 345 fathoms.

xStation 235, 565 fathoms (South Pacific).

xStation 200, 255 fathoms; xStation 21)5, 1050 fathoms (Pacific).

XStation 237, 1875 fathoms (Pacific).

Japan (African-Indian-Pacific).

Niphon.

Ousima ; Hakodadi.

Niphon (Pacific).

China ; Yeddo (Indo-Pacific).

China ; Hakodadi.

REPORT ON THE ECHINOIDEA.

265

EcHiNiD^, Agass.
TemnopledriDjE, Des.
Temnopleurus, Agass.

T. reynaudi, Agass.,
X T. toreuniaticus, Agas.s.,

Pleurechinus, Agass.
0P. bothryoides, Agass., .

Microcyphus, Agass.

M. nmculatus, Agass., .
M. zigzag, Agass., .

Salmacis, Agass.

S. dussumieri, Agass., .
X S. rarispina, Agass.,
iS. sulcata, Agass.,

Mespilia, Des.

M. globulus, Agass.,

Triplechinid/e, a. Ag.

Phymosoma, Haime.
P. crenulare, A. Ag.,

Echinus, Eond. (Linn.)
0£. norvegicus, Diib. o. Kor.,

Toxopneustes, Agass.
T. pileolus, Agass.,

Hipponoe, Gray.

H. variegata, A. Ag.,

CLYPEASTRID^, Agass.

EucLYPE ASTRIDE, Hreckel.

FiBDLABiNA, Gray.

Fibularia, Lamk.

F. australis, Desml,
F. volva, Agass., .

ECHINANTHID^, A. Ag.

Clypeaster, Lamk.

C. scutiformis, Lamk., .

Echinanthus, Breyn.

E. testudinarius. Gray, .

LiGANIDiE, Des. (emend.).

Laganuin, Kl.

L. depressum. Less.

L. putnami. Bam, . . .

Peronella, Gray.

P. decagonalis, A. Ag., .

Range in Depth and Principal Localities.

{ Nagasaki; Yeddo; x Yokohama, 5-25 fathoms; Hakodadi; xKobi, 8-52
I fathoms (Indian).

China ; North China (Indian).

China; North China; x Station 203, 12-20 fathoms (Indo- African).

X Kobi ; Jajjan, 8-50 fathoms.

Oosima (Indian).
Kagosima (Indian).

China (Indian).

Shanghai ; x Station 203, 12-20 fathoms (Indo-Afrlcan).

China (Indo- African).

China ; Ousima (Indo- Pacific).

Hakodadi.

J X Station 232, 345 fathoms; x Station 235, (label says) 365 fathoms
( (Atlantic).

Formosa ; Japan (African-Indian-Pacific).

Ousima (African-Indian-Pacific).

Ousima (Pacific).
Formosa (Indo- African).

Formosa (African-Indian- Pacific).
Hakodadi (Pacific).

Hong Kong (African-Indiau-Pacific).
Formosa ; Ousima (Indian).

Hong Kong ; Japan (Indo-Pacific).

(ZOOL. OHALL. EXP.^-PABT IX. — 1880.)

I 34

2G6

THE VOYAGE OF H.M.S. CHALLENGER.

Range in Depth and Principal Localities.

SCDTELLIDiE, AgaSS.

Echinarachnim, Leske.
E. mimbilis, A Ag.,

Hakodadi.

Echinodisnis, Brej'n.

E. Icevis, A. Ag., . . .

China Sea, 20 fathoms ; Onsima (Indo- African).

Astriclypeus, Verrill.
X A. manni, Verrill, . . .

China ; Yeddo ; x Inland Sea, Japan.

PETALOSTICHA, Hceclsel.

Spatangid^, Airass.

POURTALESM), A Ag.

Pourtalesia, A. Ag.
*P. laguncula, A Ag., .

X Station 232, 345 fathoms (Pacific).

Cystechimis, A. Ag.
*(7. clypeatus, A Ag.,

X Station 205, 1050 fathoms (South Atlantic).

Ananchytid^, Alb. Gras.

_

Linopneustes, A. Ag.
*L. murrayi, A. Ag.,

X Station 232, 345 fathoms (Pacific).

Spatangina, Gray.

Spatangus, Kl.
S. lUtkeni, A. Ag.,

Formosa ; Hakodadi.

Maretia. Gray.

M. alia, A. Ag., .
M. plamdata, Gray,

Kagosima (Indian).

China (African-Indian-Pacific).

Lovenia, Des.
X L. svhcarinata, Gray,

China; Hakodadi; xHong Kong, 10 fathoms (Indian-Pacific).

Echinocardium, Gray.
X E. australe, Gray, . . .

( China ; Japan ; x Kobi, 8-50 fathoms ; x Station 234, 2675 fathoms
( Southern Ocean).

(Indian-

LeskiaDjE, Gray.

Palceostoma, Loven.
P. mirabilis, Lov.,

Hong Kong (Indian).

Brissina, Gray.

Hemiaster, Des.
*H. gibbosiis, A Ag.,

X Station 232, 345 fathoms (Pacific).

Rhinobrissiis, A. Ag.

R. pyramidalis, A. Ag. .

China.

Brissopsis, Agass.
X B. luzonica, A. Ag.,

(Formosa; xStation 203, 12-20 fothoms ; x station 232, 345
( (Indo-Pacific).

fathoms

Faorina, Gray.

J*", chinensis, Gray,

China ; Hong Kong ; Shanghai (Pacific?).

Schimster, Agass.
*S. japonicus, A. Ag.,
X S. ventricosus, Gray,

J X Yokohama, 8-14 fathoms; x Kobi, Japan, 8-50 fathoms; xHor
j 10 fathoms; xStation 233 B., 15 fathoms (Pacific).
Hong Kong; xStation 232, 345 fathoms (Indo-Pacific).

ig Kong,

REPOKT ON THE ECHINOIDEA.

267

Of the Japanese and Chinese species Schizaster japo7iicus is the only new littoral
species collected by the Challenger. The habitat of Pleicrechinus is determined for the
first time, and Echinus norvegictis and Dorocidaris pajnUata are recorded for the first
time as coming from the Pacific. As far as the other deep-water species are concerned there
are of the continental Indo-African Ccelopleurus maillardi, Micropyga tuhercv.latum,
while Podocidaris, Fhormosoma, Asthenosoma, and Pourtalesia are Pacific abyssal, with
the exception of Asthenosoma varium, and the Japanese representative continental
Linopneustes murrayi and Goniocidaris fiorigera.

Pacific Ocean.

DESMOSTICHA, Hasckel.

C I D A R I D ^E, Miill.

GoNiociDARiD^, Hajckel.

Cidaris, Kl

C rtietularia, BL, .

Dorocidaris, A. Ag.
*Z). bracteata, A. Ag.,
0A 2Mj)illata, A. Ag.,

Phyllacanthus, Br.
X P. annulifera, A. Ag.,

xP. baculosa, A. Ag.,

P. dubia, Br.,
X P. (jigantea, A. Ag.,

P. imperialis, Br., .

xP. verticillata, A. Ag.

Porocidaris, Des.
*P. elegans, A. Ag.,

Goniocidaris, Des.

G. canaliculata, A. Ag.,
*G. fiorigera, A. Ag.,

Salenid^e, Agass.

Salenia, Gray.
*& hastigera, A. Ag.,

ARBAClADiE, Gray.

Podocidaris, A. Ag.
*P. prionigera, A. Ag., .

Cailopleunis, Agass.
©C'. maillardi, A. Ag.,

Range in Depth and Principal Localities.

Solomon and Sandwich Islands (African-Indian-Pacific).

xAmboyna, 15-100 fathoms.
^Station 210, 375 fathoms (Atlantic).

South Sea; xCape York; xStation 186, 8 fathoms; ^Station 188, 28

fathoms (Indian).
Samboangan, 10 fathoms (Indo-African).
Bonin Islands ; New Caledonia (Indo-African).
Sandwich Islands (African-Indiau-Paciflc).
Tonga (African-Indian-Pacific).
Navigator Islands; Society Islands; Sandwich Islands; x station 186,

8 fathoms (African-Indian-Pacific).

xStation 214, 500 fathoms.

Caroline and Sandwich Islands (Southern Ocean).
xStation 192, 129 fathoms.

xStation 1 70, 630 fathoms ; xStation 171, 600 fathoms; xStation 195,
1425 fathoms; xQff Cebu, 100 fathoms (Atlantic).

XStation 218, 1070 fathoms.

xStation 192, 129 fathoms; xAmhoyna, 100 fathoms (Indo-African).

268

THE VOYAGE OF H.M.S. CHALLENGER.

UiADEMATiD^, Peters.

Diadema, Soliynv.
X D. setosum, Gray, .

Centrostepharms, Pet.
C. rodgersii, A. Ag.,

Aspidodiadenia, A. Ag.
*A. tmismn, A Ag.,

Echinoihrix, Pet.
X E. calamaris, A. Ag.,
E. desorii, Pet.,

xE. turcanim, Pet., . .

Micropyga, A. Ag.
*ilf. tubcrcukiHim, A Ag.,

Astropyga, Gray.

4. elastica, Stud., .

0.4. pidvinata, Agass., .

EcHiNOTHURiD.a;, Wy. Thom.

Asthenosoma, Grube.
*A. coriaceum, A Ag.,

*A. gracile, A. Ag.,

*A. gruhii, A. Ag., .
*A. peUucidum, A Ag., .

Phormosoma, Wy. Thom.
*P. lucukntum, A. Ag., .
*P. teime, A. Ag., .

EcHiNOMETRAD^, Gray.

Cololocentrotvs, Br.
G. atratus, Br.,
C. Tnertensii, Br., .

Heterocentrotus, Br.
X iT. mammillatvs, Br.,
X IT. trigonarius, Br.,

EcMnometra, Bond. (Breyn.).

X £. lucunter, Bl.,

.B. oblonga, Bl.,

Parasalenia, A. Ag.
P. gratiosa, A Ag.,

Stomopne^istes, Agass.
S. variolaris, Agass.,

Eange in Depth and Principal Localities.

(Fiji Islands; Sandwich Islands; xC'ebu; x Papeete Reel (Atlantic;
\ Pacific).

New Caledonia (Australian).

I) xOff Cebu, 100 fathoms; xStation 170, 630 fathoms; xStation 171, 600
( fathoms.

Society Islands ; xKandavu Reef ; x Cebu ; x Tahiti.

Fiji Islands (African-Indian-Pacific).
( Bonin, Navigator, and Sandwich Islands; xKandavn Reef (African;
j Indian; Pacific).

< Station 174, 610 fathoms; xStation 219, 150 fathoms; xQff Cebu,
100 fathoms.

New Britain, 20 fathoms.

; XStation 188, 28 fathoms; xStation 190, 49 fathoms; xHonolulu, 18
' fathoms (Panama).

xStation 172, 240 fathoms; xStation 173, 310-315 fathoms.

XStation 169, 700 fathoms; xStation 184, 1400 fathoms; xStation 219,

150 fathoms.
xSamboangan, 10 fathoms,

X Off Cebu, 100 fathoms; xStation 192, 129 fathoms.

xStation 191, 800 fathoms.

XStation 272, 2600 fathoms; xStation 274, 2750 fathoms.

Sandwich Islands (African-Indian-Pacific).
Bonin Islands.

Fiji Islands; Sandwich Islands; xKandavu Reef (African-Indian-
Pacific).
New Caledonia ; Sandwich Islands (African-Indian-Pacific).

New Caledonia, Loo Choo ; Sandwich Islands ; x Samboangan, 10 fathoms ;

xKandavu Reef; x Off Cebu; x Papeete Reef ; xTongatabu, 18 fathoms

(African ; Indian ; Pacific).
Solomon and Sandwich Islands.

5 Bonin Islands ; New Caledonia ; Sandwich Islands (African-Iiidian-
\ Pacific).

Navigator Islands (Indo- African).

REPORT ON THE ECHINOIDEA.

269

Strnngylocentrotus, Br.
0.S'. eurythrogrammiis, A. Ag.,
iS. gibhosiis, A. Ag.,
S. nudus, A. Ag., .
iS. tuberculatus, Br.,

Sph(erecMniis, Des. '
S. australioe, A. Ag.,

Psevdobohtia, Trosch.

P. (jramdata, A. Ag., .
@P. indiana, A. Ag.,

Echinostrephtis, A. Ag.
J^. molare, A. Ag., .

E c H I N I D iE, Agass.

Temnopledrid^e, Des.

Temnopleurus, Agass.
X T. hardxoickii, A. Ag., .
X T. reynaudi, Agass.,
T. ioreumaticus, Agass.,

Pleurechinus, Agass.
0P. bothryoides, J^ass., .

Primechinus, A. Ag.
*P. sagittiger, A. Ag.,

CoUaldia, Des.
*-C. forbcsiana, A. Ag.,

Microcyphns, Agass.

ilf. maculatus, Agass., .

Trigonocidaris, A. Ag.
*r. monolini, A. Ag.,

Sahnacis, Agass.
X S. bicolor, Agass., .
X S. dussumieri, Agass.,
X S. globator, Agass.,
X &'. rarispina, Agass.,
X S. sulcata, Agass., .

Mespilia, Des.
X M. globulus, Agass.,

Amblypnevstes, Agass.
A. pallidus, Val., .

Triplechinid^e, a. Ag.

Echinus, Roud. (Linn.).
0_B. acutus, Lamk., .
©S. elegans, Dub. o. Kor.,

Toxopnexistes, Agass.
T. maculahis, A. Ag.,

Range in Depth and Principal Localities.

X T. pileolus, Agass.,

xNew Caledonia (Australian).
Fiji Islands; Galapagos (Chilian).
Sandwich Islands ; Galapagos (Indian).
South Sea (African ; Australian).

South Sea ; Fiji Islands (Australian).

Sandwich Islands.

X Samboangan, 10 fathoms (Indo- African).

Kingsmills ; Society and Sandwich Islands (African-Indian- Pacific).

''Arafura Sea; x Station 192, 129 fathoms (Indian)

X Station 219, 150 fathoms; x Station 192, 129 fathoms (Indian).

New Caledonia (Indo- African).

X Station 186, 8 fathoms (Galapagos ?).

xStation 207, 700 fathoms; xStation 218, 1070 fathoms.

.xStation- 173, 310-315 fathom-s.

South Pacific ; Navigator Islands (Indian).

XStation 170, 520 fathoms.

xSamboangan, 10 fathoms (Indo- African).

xAmboyna, 100 fathoms; x Station 212, 10-20 fathoms (Indian). ■

xStation 186, 8 fathoms (Indian).

xStation 186, 8 fatlioms; xStation 188, 28 fathoms (Indo-African).

xOflf Cebu (Indo-African).

\ Sandwich Islands; Navigator Islands ; Tonga; xSamboangan, 10 fathoms
( (Indian-Pacific).

Fiji Islands (Australian).

xStation 170, 630 fathoms (Atlantic).
xStation 219, 150 fathoms (Atlantic).

Fiji Islands ; Christmas Island.

Na^gator Islands; Fiji Islands; x Honolulu; xSamboangan, 10
fathoms (African- Indian- Pacific).

270

THE VOYAGE OF H.M.S. CHALLENGER.

Hipponoli, Gray.
X H. variegata, A. Ag.,

Evechiniis, Verrill.
X E. chloroticus, Verrill., . .

CLYPEASTRID^, Agass.

EuclypeastriDjE, Haeckel.

FiBDLARlNA, Gray.

Filndaria, Lamk.

F. a-ustralis, Desml.,
X F. volva, Agass., .

ECHINANTHIDiE, A. Ag.

Clypeaster, Lamk.
X G. humilis, A. Ag.,

X G. scutiformis, Lamk., .

Echinaiithus, Breyn.

E. testudinarius, Gray, .

LAGANlD.a;, Des. (emend.).

Laganum, Kl.
L. boncmi, KL,

X L. dcpressum, Less.,

©L. putnami, Barn.,

Peronella, Gray.

X P. decagonalis, A. Ag., .

ScuTEiHD^, Agass.

AracKnoides, Kl.

A. placenta, Agass.,

Echinodiscus, Breyn.
X E. Iccvis, A. Ag., .

PETALOSTICHA, Hajckel.

CASSIDDLIDiE, AgaSS.

EcHiNONiD.*;, Agass.

EcMnonens, Van Phel.
E. cyclo$to7nus, Leske, .

Echinolampas, Gray.
X E. oviformis, Gray,

Catopygus, Agass.
*0. recens, A. Ag., .

Nucleolites, Lamk.
N. epigomis, Mart.,

Range in Depth and Principal Localities.

Pelew; Fiji and Sandwach Islands; xSamboangan, 10 fathoms;
X Kaudavu (African-Indian-Pacific),

Christmas Island ; x Kandavu Reef (Australian).

Sandwich Islands ; South Sea.

Kingsmills Islands; x Station 188, 28 fathoms (Indo- African).

New Caledonia ; x Station 21 2, 10-20 fathoms ; x Amboyna, 15-20 fathoms
(Indo-African).

Kingsmills Islands; Sandwich Islands; xNew Caledonia (African-
Indian-Pacific).

Sandwich Islands.

Pelew Islands (Indian),
(South Pacific; xArafiira Sea; Fiji and Sandwich Islands; x Station
( 187, 6 fathoms (African-Indian- Pacific).

xAmboyna, 15-25 fathoms (Indian).

r New Caledonia ; x Caspar Straits, 12 fathoms ; xAmboyna, 15-20 fathoms ;

I xTongatabu; x Tahiti, 20 fathoms ; x Torres Straits ; x Station 173,

J 310-315 fothoms; xStation 186, 8 fathoms; xStation 188, 28 fathoms;

X Station 190, 49 fathoms; xStation 192, 129 fathoms ; xStiition 208,

18 fathoms; xStation 212, 10-20 fathoms; xStation 219, 150 fathoms

(Indian-Pacific).

South Sea ; Solomon Islands (Indian ; Australian).

New Caledonia (Indo-African).

Navigator, Kingsmills, and Sandwich Islands (African-Indian-Pacific).
xStation 192, 129 fathoms (Indo-African).
XStation 192, 129 fathoms.
Lord Hood's Island (Indian).

REPORT ON THE ECHINOIDEA.

271

SPATANOIDiE, AgaSS.
POUETALESLE, A. Ag.

Pourtalesia, A. Ag.
*P. laguncula, A Ag.,
*P. rosea, A. Ag., .

Ananchttid^, Alb. Gras.

Palceotropus, Lov.
*P. loveni, A. Ag., .

Argopatagiis, A. Ag.
*A. vitreus, A. Ag.,

Honwlampas, A. Ag.
*H. fulva, A. Ag., .

Linopneustes, A Ag.
*L. murrayi, A. Ag.,

Spatangina, Gray.

Maretia, Gray.
0Af. aZte, A. Ag., .

X M. planulata, Gray,

Ewpatayus, Agass.
0£. valenciennesii, Agass.,

Lovenia, Des.
xX. elongata, Gray, .
i. subcarinata, Gray,

Breynia, Des.

P. australasim, Gray,

Brissina, Gray.

Hemiaster, Des.
*il. gihhosus, A. Ag.,

Rhinohrissiis, A. Ag.
*P. hemiasteroides, A. Ag.,

Cionobrissns, A. Ag.
*C. revindiis, A. Ag.,

Brissopsis, Agass.
X P. luzonica, A Ag.,

Aerope, Wy. Thorn.
*.4. rostrata, Wy. Tliorn.,

.4ccs<«, Wy. Thorn.
*^. hellidifera, Wy. Thom.,

Brissus, Kl.

P. carinatus, Gray,

Range in Depth and Principal Localities.

xStation 191, 800 fathoms; xStation 244, 2900 fathoms.
=< Station 272, 2600 fathoms.

XStation 210, 375 fathoms.
X Station 191, 800 fathoms.
xStation 271, 2425fathoms.
xStation 210, 375 fathoms.

xStation 191, 800 fathoms; xStation 192, 129 fathoms (Indian).
Kingsmills Islands ; New Caledonia ; x Admiralty Islands, 16-25 fathoms ;
xLevulia Reef (African-Indian- Pacific).

xStation 188, 28 fathoms; xArafura Sea (Australian).

xStation 188, 28 fathoms; xStation 212, 10-20 fathoms (Indo-African).
Sandwich Islands (Indian-Pacific).

Sandwich Islands; x Torres Straits (Indo-African).

xStation 191, 800 fathoms..

X Tahiti, 20 fathoms. •

XStation 191, 800 fathoms.

( New Caledonia ; x Tahiti Harbour ; xStation 188, 28 fathoms; xStation
I 191, 800 fathoms (Indian- Pacific).

XStation 191, 800 fathoms.

X Station 272, 2600 fathoms.

Pelew, Fiji, Society and Sandwich Islands (African-Indian-Pacific).

272

THE VOYAGE OF H.M.S. CHALLENGER.

Kange in Depth and Principal Localities.

Metalia, Gray.
X M. maculosa, A. Ag., . . - .

M. stcrnalis, Gray,

Linthia, Mer.

L. rostrata, Smith,

Faorina, Gray.

F. chinensis, Gray,

Schkaster, Agass.

S. japonicus, A. Ag.,
iS. ventricosits, Gray,

Periaster, D'Orb.
©P, limicola, A. Ag.,

Moiropsis, A. Ag..
*-M. daudicans, A Ag., .

j Kingsmills, Navigator, Society, and Sandwich Island.s; x Station 188, 28
( fathoms (African-Indiaii-Pacific).

J New Caledonia, Navigator, Society, and Sandwich Islands (African-
l Indian- Pacific).

Pacific Islands.

Sandwich Islands.

X Station 188, 28 fathoms.

Pelew and Fiji Islands (Indian-Pacific).

X Station 188, 28 fathoms (Atlantic).

X Station 192, 129 fathoms.

The list of species marked here as Pacific includes not only the strictly littoral Pacific
species, but also the Indo-Pacific species, and sucli Indo- African species as encroach to
the eastward upon the southern Iwundary of the Chinese and Japanese districts, the west-
ward boundary of the Pacific, and the northern limits of the Australian realm.

Of the species collected by the Challenger there have only been found among the
littoral species Rhinohrissushemiasteroides, Schizaster japonicus and Moiropsis daudicans
which were not previously known. ■ Of these Schizaster japonicus is probably a Japanese
and Chinese species, while Moiropsis daudicans, and perhaps Schizaster japonicus may
be East Indian species which find their south-eastern limits at the western edge of the
Pacific district.

The range of Astropyga pulvinata, Brissopsis luzonica, Strongylocentrotus eurytho-
grammus (an Australian species), of Ccelophurus maillardi (an East Indian species), of
Pleurediinus hothyryoides, Pseudoholetia Indiana, Salmacis dussumieri, S. glohator
(Australian), Salmacis rarispina (Indian), Evechinus chloroticus (a New Zealand
species), Laganum putnami, Maretia alta, Temnopleurus hardwicki, Temnopleurus
reynaudi (Japan and China species), Lovenia elongata (Sandwich Islands), and Metalia,
maculosa have been greatly extended, while Echinus acutus is another eminently
Atlantic species which has found its way far into the Pacific to the Kermadec Islands,
and Dorocidaris papillata and Echinus elegans to the Philippine Islands.

As probably representative continental species of the Pacific we must class Dorocidaris
hracteata, Asthenosoma gracile, A. pellucidum, A. grubii,, Catop>ygus recens, and
Linopneustes murrayi ; as probably continental representatives of the East Indian
fauna, Cottaldia forhesiana, Podocidaris prionigera, and Micropyga tuberculata; of

EEPORT ON THE ECHINOIDEA.

273

the continental Australian Goniocidarls Jlorigera, and perhaps of the Southern Ocean
Porocidaris elegans.

WhUe of the abyssal species common to the Atlantic and Pacific we have Salenia
hastigera, Aspidodiadema tonsum, Aerope rostrata, Periaster limicola, and Aceste
bellidifera.

As strictly Pacific representative abyssal species we can enumerate Asthenosoma
coriaceum, Phormosoma tenue, Phormosoma luculentiim, PJiormosoma hursaria, Trigono-
cidaris monilini, Prionechinus sagittiger, Pcdeotropus loveni, Pourtalesia laguncula,
Pourtalesia rosea, Homolampas fidva, Cionobrissus revinctus, and ArgojKitagits vitreus,
the Southern Ocean species extending only into the southern part of the Pacific, as in the
Atlantic, in the South American, and Australian districts, but a greater numlier of species
than we find going northward in the Atlantic.

West, South, East, a^sD North-East Australia — New Zealand.

Range in Depth and Principal Localities.

DESMOSTICHA, Ha;ckel.

C I D A R I D ^, MtUl.

GoNiociDARiD.«, Hreckel.

Phyllacanthns, Br.

P. annulifera, A. Ag., .

P. duhia, Br., ....

P. imperialis, Br., .

P. verticillata, A. Ag., .

Stephanocidaris, A. Ag.
S. bispinosa, A. Ag.,

Porocidaris, Des.
*P. elegans, A. Ag.,

Goniocidaris, Des.

G. geranioides, Agass., .

X G. tubaria, Liitk., .

ArbaciaDjE, Gray.

Arbacia, Gray.

A. austraUs, Trosch,

DiADEMATiD^, Peters.

Centrostephanm, Pet.
C rodgersii, A. Ag.,

ECHINOTHDRID.E, AVy. Thoiu.

Phormosoma, Wy. Thom.
*P. hoplacantha, Wy. Thorn., .
*P. rigidum, A. Ag.,

South Sea (Indo-Pacific).
Au-stralia (Indo- African).
Australia (African-Indian-Pacific).
South Sea (African-Indian- Pacific).

Australia (Indian).

X Station 164n, 410 fathoms (Pacific).

Murray River; West Australia (Indian).
( Bass Straits; Tasmania; xStation 161, 38 fathoms; x Station 162, 38-40
\ fathoms.

Australia.

Sydney ; Houtman's Abrolhos.

xStation 164«, 410 fathoms (Southern Ocean).
xStation 169, 700 fathoms (Southern Ocean).

(ZOOL. CHALL. EXP. — PART I.X. 1881.)

135

•274

THE VOYAGE OF H.M.S. CHALLENGER.

EcHiNOJiETRAD^, Gray.

Echinometra, Rondel. (Breyn.).
E. lucimter, Bl.,

Stronyylocentrotus, Br.
S. armiger, A. Ag.,

X S. eurythroyrammus, A. Ag.,

S. tuberculatus, Br.,

Sphcerechimis, De.s.
X S. anstmlicc, A. Ag.,

EcHiNiD^, Agass.

Temnopleurid.«, Des.

Temnopleurus, Agass.
0r. reynaiidi, Agass.,

Prionechinus, A. Ag.
*P. sagittiger, A. Ag.,

Micromjphus, Agass.

M. -maculatus, Agass., .

X M. zigzag, Agass., .

Salrruicis, Agass.

S. globator, Agass.,
S. rarispina, Agass.,
S. sulcata, Agass., .

A mhlypneustes, Agass.

X A. formosm, Val., .

A. griseus, Agass., .

A, ovum, Agass., .

A. pallidus, Val., .

Holopneustes, Agass.
H. inftatus, A. Ag.,
H. porosisdmus, Agass.,
X H. purpiirescens, A. Ag.,

Triplechinid^, a. Ag.

Echinus, Bond. (Linn.).
E. alboeinctus, Hutt.,
E. angulosus, A. Ag.,
E. darleyensis. Wood,
E. elevatiis, Hutt., .
E. magellanicxis, Phil.,
E. margaritaceus. Lain.,

Hipponoe, Gray.
QH. variegata, A. Ag.,

Evechinus, VerrUl.

E. chloroticus, Vemll,

Range in Depth auci Priucipal Localities.

North Australia ; Houtman's Abrolhos (African-Indian-Pacific).

Australia.

North Australia; New Zealand; Murray River; x Sydney, 6-15, 30-35

fathoms.
Sydney (Indo- Pacific).

New Zealand; East Australia ; Adelaide; x Station 162,38-40 fathoms
(African).

X Station 166, 275 fathoms (Indian).

X Station 164, 950 fathoms (Pacific).

Tasmania ; West Australia (Indian).

Australia; xgtation 161, 38 fathoms; xStation 162, 38-40 fathoms
(Indian).

Australia (Indian).

Cape York (Indo- African).

Port Mackay (Indo- African).

Tasmania ; Adelaide ; xStation 162, 38-40 fathoms.
New Zealand ; Sydney ; Adelaide.
Sydney ; Port Lincoln.
Port Philip ; Adelaide.

East Australia ; New Zealand.

Australia.

Australia; Tasmania; Murray River; xPort Jackson, 6-15 fathoms.

New Zealand.

New Zealand ; Adelaide (African-Indian-Southern Ocean).

Australia.

New Zealand.

New Zealand ; Australia (Southern Ocean).

South Sea ; New Zealand (Southern Ocean).

>-Port Jackson, 6-15 fathoms (African-Indian- Pacific).
New Zealand.

REPORT ON THE ECHINOIDEA.

275

CLYPEASTRIDiE, Agass.
EucLYPEASTRiD-E, Hieckel.
FiBULARlNA, Gray.
Fihularia, Lamk.
X F. australis, Desml.,
F. volva, Agass., ...

ECHINANTHID*, A. Ag.

Echinanthus, Breyn.
xE. testudinarius, Gray, .

Laganid^, Des. (eineucl.).

Laganum, Kl.
L. honani, Kl.,
L. dejiressum, Less.,
L. ^nitnami, Barn.,

Peronella, Gray.

P. decagonalis, A. Ag., .

X P. peronii, Gray, .

P. rostrata, A. Ag.,

PETALOSTICHA, Hsckel.

CassiddliDjE, Agass.

NccLEOLiDiE, Agass.

Echinobrissus, Breyn.
E. receiis, D'Orb., .

Spatangid*, Agass.

POURTALESLS:, A. Ag.

Pourtalesia, A. Ag.
*P. laguncula, A. Ag., .

Spatangina, Gray.

Maretia, Gray.
0Af. 2>lanulata, Gray,

Eupatagus, Agass.
X E. valenciennesii, Agass.,

Lovenia, Des.

L. elongata, Gray,

Breynia, Des.
05. mistralasice, Gray,

Echinomrdium, Gray.
X E. australe, Gray, .

Brissina, Gray.

Brissojtsis, Agass.
X B. luzonica, A. Ag.,

Metalia, Gray.

M. stemalis, Gray,

Linthia, Mer.

L. australis, A. Ag.,

Range in Depth and Principal Localities.

Coral Sea; xPort Jackson, 30-35 fathoni-s; x Station 164-950 fathoms

(Pacific).
North Australia (Indo- African).

Australia; ^Station 161, 38 fathoms ; xStation 163, 120 fathoms (Pacific).

Tasmania ; Australia (Indian).
Australia (African- 1 ndian- Pac ifi c) .
Australia (Indian).

West Australia (Indo-Paciflc).

BrLsbane Water; Tasmania; xStation 162, 38-40 fathoms; xport

Jackson, 30-35 fathoms (Indian).
New Zealand (Indo-African?).

New Zealand (Indo-African).

xStation 168, 1100 fathoms; xStation 169, 700 fathoms (Pacific).

xPort Jackson, 6-15 fathoms (Afiican-Indian- Pacific).
Port Dabymple; Tasmania; xPort Jackson, 30-35 fathoms.

Port Dalrymple ; West Australia (Indo-African).

South Sea; Sydney ; West Australia; x Torres Straits (Indo-African).

New Zealand; West Australia; x Port Jackson, 6-15 fathoms (Indian-
Southern Ocean).

XStation 168, 100 fathoms (Indian-Pacific).

North Australia ; Sydney ; New Zealand (African-Indian- Pacific).

Flinders Island ; Tasmania.

276

THE VOYAGE OF H.M.S. CHALLENGER.

The northern and western boundaries of the Australian district encroach into tlie
Indo-African limits, while the eastern extension of the Australian district laps far into
the Pacific, or rather the whole of the Australian field seems to be cut out of the Indo-
Pacific realm.^ We find encroaching into the south-eastern limits abyssal species
from the extension of the Pacific abyssal fauna : Pliormosoma hoplacantha, Porocidaris
elegans, and PoxtrUdesia lagnncnla, while Prionechinns sagittiger is probably only an
abyssal species characteristic of the Indo-African realm.

Of the littoral species already known, Temnoplexirus reynaudi, Hvpp)0^i-oe variegata,
Maretia planidata, and Brissopsis luzonica were found by the Challenger to extend far
into the Australian littoral district.

Antarctic and Southern Ocean.

DESMOSTICHA. Hseckel.

CiDARIDiE, Miill.

GoNiociDARiD^, Hceckel.
Goniocidaris, Des.
X G. carmliculata, A. Ag.,

Arbaciad^, Gray.
Arbacia, Gray.
X A dufresnii, Gray, .

EcHiNlD^, Agass.
Triplechinid^, a. Ag.
Echinus, Eond. (Linn.)
xE. magellaniciiijVhil., .

X E. numjaritaceus, Lam.,

PETALOSTICHA, Hteckel.

SPATANGID.E, AgaSS
POURTALESI^, A. Ag.

Pourtalesia, A. Ag.
*P. carinata, A. Ag.,
*P. ceratopyya, A. Ag., .
*P. hispida, A. Ag.,
X P. phiale, Wy. Thorn., .

Spatagocystis, A. Ag.
*S. challetujeri, A. Ag., .

Echinocrepis, A. Ag.
*E. cuneata, A. Ag.,

Range in Depth and Principal Localities.

j X Station 147, 1600 fathom.?; x Station 149, 25 fathoms; xKerguelen,
/ 20-150 fathoms.

xNightingale Islands, 100-150 fathoms; xStation 151, 75 fathoms;
X Station 153, 1675 fathoms; >; Station 156, 1975 fathoms (South
America).

xStation 145,150-310 fathoms; xStation 147, 1600 fathoms; ^Marion

Island, 50 fathoms.
X Christmas Harbour, 50-120 fathoms; xStation 150, 150 fathoms;

xStation 151, 75 fathoms.

xStation 147, 1600 fathoms ; xStation 157, 1950 fathoms (South Pacific).
XStation 157, 1950 fathoms (South Pacific).

X Station 147, 1600 fathoms ; xStation 156, 1975 fathoms (Southern Ocean).
xStation 156, 1975 fathoms (Atlantic).

xStation 147, 1600 fathoms; xStation 157, 1950 fathoms.
XStation 147, 1600 fathoms.

■>• A number of Indo-African species extending into the Australian realm and into the Chinese districts have been
added to the list, as no list of Indo-African species is given.

E.EPORT ON THE ECHINOIDEA.

277

Range in Depth and Principal Localities.

Urechinm, A. Ag.
*U. naresianus, A. Ag., .

Cystechinus, A. Ag.
*6'. vedca, A. Ag., ....

*6'. iinjvillii, A. Ag.,

ANANCHYTIDiE, Alb. Grae.

Genicopatagus, A. Ag.
*(?. affinis, A. Ag., ....

Brissina, Gray.

Hemiaster, Des.
X if. cavernosus, A. Ag., .

Schizaster, Agass.
*S. moseleyi, A. Ag.,

( X Station 146, 1375 fathoms; x Station 147, 1600 fathoms; xStation 158,
I 1800 fathoms (South Pacific).

X Station 153, 1675 fathoms (South Pacific).
( xStation 146, 1375 fathoms; ^Station 147, 1600 fathoms; xStation 158,
/ 1800 fathoms (South Pacific).

XStation 157, 1950 fathoms.

( xKerguelen Islands, 10-250 fathoms; xHeard Island, Station 151,75
I fathoms.

{ xStation 146, 1375 fathoms; xCbristmas Harbour, ISOfatboms; Kerguelen
Islands, 110 fathoms.

We find extending into the Southern Ocean, that most characteristic of the abyssal
realms, Goniocidaris canalicxdata and Hemiaster cavernosus, or, perhaps better, we find
them cropping out at the Cape, Australia, and the southern extremity of South America ;
along with Echinus magellanicus and Echinus margaritaceus. The only new littoral
species is Schizaster moseleyi, while it is interesting to find that all the other deep-sea
species belong without exception to the Pourtalesise. Of the deep-sea species Pourtalesia
phiale is the only one which finds its way into the northern Atlantic as far as Europe in
deep water. A comparatively large number of species of Antarctic Pourtalesise and
South Pacific Echinothuridse find their way northward into the Pacific.

278 THE VOYAGE OF H.M.S. CHALLENGEK.

EXPLANATION OF THE PLATES.

With the exception of Pis. XIII., XIX.% XXVIL, and XXVIIL, which were drawn
on stone by Mr A. Sonrel, of Pis. X.% X.^ XIX., XXIX., XLIV., XLV., drawn by Mr
Trouvelot, and Pis. XXXVI. , XXXVII. , XLIL, and XLIIL, drau-n by Mr Meisel, the
other plates were all lithographed by Mr Paulus Roetter, who had gained considerable
experience in drawing Echinids while making the plates of the Revision of the Echini.
The general views were cbawn by him dii-ectly on stone from nature ; the greater part of
the structural drawings were copies of sketches which I made myself to illustrate the
details of parts to be seen only from preparations of the test. The greater number of
the figures of Pedicellaria^, drawn on stone by Mr Meisel and by Mr Trouvelot, were
drawn by myself, with the exception of some drawings on the plates of Pedicellariee, and
of the sections of spines, drawn fi'om nature by Mr James H. Blake. The sections of
spines were made by Mr A. A. Julien, of the Columbia School of Mines.

PLATE I.

Cidaris [Dorocidaris) bracteata, A. Ag. (fig. 1), p. 37.
Fig. 1. Primary radiole.

Cidaris trihxdoides, Bl. (figs. 2-6), p, 36.

,, 2. Small specimen of Cidaris ;n6tt?oic?es, measuring 18 mm. in diameter, in which
the radioles have the shape characteristic of Phyllacanthus veiiicillata.

,, 3. A single primary radiole magnified (-^).

„ 5. A smooth primary radiole similar to those of the lower side of the test in Cidaris
trihuloides (f ).

„ 6. Another primary radiole, in which the verticillation is not so marked as in fig. 3 (f ).

Goniocidaris Jlorigera, A. Ag. (figs. 7-20), p. 46.

,, 7. A specimen (n.s.) seen from the abactinal side, in which the spines are all of the

shape of figs. 8-11, and quite uniform in their aj)pearance.
., 8, 9. Primary radioles, with sharp spines of fig. 7.

REPORT ON THE ECHINOIDEA. 279

Fig. 10. Smooth radiole of actinal side.

,, 1 1. Small radiole surrounding the actinostome.

,, 12. Specimen of Goniocidaris fiorigera, in which the primary radicles present the
usual variation of the tip, especially on the abactinal surface, characteristic of
the genus ; natural size.

,, 12 a. Abactinal area of the same species, partly denuded; magnified.

„ 13. Portion of denuded test of the same species, facing the median line of an ambu-
lacral area ; magnified.

„ 14. Portion of an interambulacral area of same, from the equatorial zone of test.

„ 15 o, h. The cupuliform radioles of the abactinal region are seen from above, repre-
sented in profile in c, d. (f-).

„ 16 a, h. End view and profile of a different cupuliform radiole, 15 and 16 are taken
from the abactinal region of the test, the principal primary radioles of fig. 1 2
are cylindrical (fig. 18), with prominent irregularly-arranged spines scattered
over the shaft.

,, 17. Small radiole of actinal side of test, near the actinostome (f ).

„ 18. Basal part of shaft of primary cylindrical radioles.

„ 19. Primary radiole near actinal edge of test.

,, 20. Tapering spiniferous radiole, similar to those of fig. 7, taken from specimen
of fig. 12.

PLATE II.

Goniocidaris canaliculata, A. Ag. (figs. 1-18), p. 43.

Fig. 1. Specimen with long spines, seen from the abactinal side ; natural size.

,, 2. Specimen -mth short spines, seen from the abactinal side, showing the mode of
carrying the young ; natural size.

„ 3. Another specimen, mth proportionately shorter spines, seen from the actinal
side ; natural size.

„ 4, 5, 6. Portions of the median interambulacral primary plates, to show the variation
in the depth of the median interambulacral groove, from a deep broad groove
(fig. 4), to a mere indistinct bare space in fig. 5.

,, 7. Edge of abactinal membrane to show the deep indentation of the median inter-
ambulacral and ambulacra! spaces of the test.

„ 8. Young specimen, 3 mm. in diameter, seen from the actinal side, denuded of spines
about in the stage of fig. 12.

,, 9. Young specimen, seen from the actinal side, 2 mm. in diameter.

„ 10. The same as fig. 9, seen from the abactinal side.

280 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 12. (This fig. should have been 11). Another young specimen, 3 mm. in diameter,
seen from the abactinal side (same as fig. 8). The abactinal spines are larger
tlian in fig. 10.

,, 12, 13. Spines of figs. 9, 10 ; magnified.

,, 14. Primary spines of fig. 1; magnified.

,, 15. Pedicellaria from the abactinal region of test.

,, 16. Pedicellarise of test, in difi'erent stages of development.

,, 17. Same kind of pedicellarise as fig. 16, fully developed.

„ 18. Profile view of large terminal abactinal tentacle of young specimens, figs. 9, 10.

PLATE III.

Povocidaris elegans, A. Ag. (figs. 1-12), p. 40.

Fig. 1. Specimen with spines, seen from the abactinal side {\).
,, 2. Specimen denuded, seen from the abactinal side {\).
,, 3. The same, from the actinostome.
,, 4. Abactinal area of another specimen, 28 mm. in diameter, probably a male with

smaller genital opening.
,, 5. A magnified portion of the test, facing the median interambulacral line near

the equatorial region of the test.
,, 6. A magnified portion of the test, facing the median ambulacral line.
,, 7. Magnified view of primary radiole.
,, 8 a. A curved serrated radiole of actinal side of test (f ), adjoining actinostome, seen

in profile, h. The same, seen from the flat side.
„ 9 a, h. Other small straight radioles, near actinostome (f ).
,, 10. Long slender tridactyle pedicellaria (4 mm.), from abactinal region of test.
,, 11. Another pedicellaria, somewhat more blunt than preceding fig., with coarse

pigment spots.
,, 12. Similar to preceding pedicellaria, with finer rows of pigment spots.
Figs. 11 and 12 are drawn on the same scale as fig. 10.

PLATE IV.

Salenia varispina, A. Ag. (figs. 1, 2), p. 55.

Fig. 1. Portion of test of Salenia varispina, facing the median interambulacral space,
magnified from a specimen measuring 10 mm. in diameter.
,, 2. Portion of test of same, facing the median ambulacral space.

REPORT ON THE ECHINOIDEA, 281

Salenia hastigera, A. Ag. (figs. 3-17), p. 54.
Fig. 3. Abactinal view of specimen of Salenia hastigera, measuring 14 mm. in diameter.

,, 4. The same species seen in profile, denuded of spines, 13 mm. in diameter.

„ 5. The same seen from the actinal side, denuded.

„ 6. The same from the abactinal side.

7. Magnified portion of the test of same facing the median ambulacral space.

,, 8. Magnified portion of the test of same facing the median interambulacral space.

,, 9. Magnified portion of actinal edge of test of same.

,, 10. Abactinal system of same.

„ 11. Still further magnified portion of the ambulacral plates, and of the adjoining
primary interambulacral plate of same.

„ 12. Young specimen, measuring 9 mm. in diameter, seen from the abactinal side.

„ 13. The same as fig. 12, seen from the actinal side.

„ 14. Magnified portion of test of same as fig. 12, facing the median ambulacral space.

„ 15. Magnified portion of test of same, facing the median interambulacral space.

,, 16. Magnified portion of abactinal system, showing madreporic body of fig. 10.

„ 16 a. Magnified portion of abactinal system, showing the rudimentary spines cover-
ing the genital and ocular plates.

„ 17. Magnified portion of primary spine of Salenia hastigera.

,, 17 a, b. Jaws of Salenia hastigera with the teeth, as seen in profile and from the
outside b.

PLATE V.

Cceloi^letirus maillardi, Mich. (figs. 1-3), p. 60.

Fig. 1. Large specimen (n. s.) with radioles, coloured light brown at base, and with shoe

of uniform tint to extremity.
,, 2. The same seen from the actinal side, to show the spathiform shoe of the radioles,

characteristic of the Arbaciadse.
„ 3. A smaller specimen, with the shoe of the radioles brilliantly banded with

Vermillion.

PLATE VL

Ccelopleurus maillardi, Mich. (figs. 1-22), p. 60.

Fig. 1. Denuded test (n. s.) seen in profile.
,, 2. The same seen from the abactinal side.
„ 3. The same seen from the actinal side.

(ZOOU CHALL. EXP. — PAET IX. — 1881.) I 36

282 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 4. Magnified view of the abactinal system.

„ 5. Magnified portion of test seen facing the median ambulacral line.

„ 6. Magnified portion of test seen facing the median interambulacral line.

„ 7. Portion of test adjoining actinostome of same.

„ 8. Smaller specimen (n. s.) seen from the actinal side (one with banded shoes, fig. 3,

PI. v.).

„ 9. Magnified portion of test facing median ambulacral line, from fig. 8.

„ 9 a. Magnified portion of test of fig. 8, facing median interambulacral line.

„ 10. Magnified portion of test of fig. 8, adjoining actinostome.

„ 11. Still smaller specimen (n. s.), seen from the actinal side.

,, 12. Magnified portion of test of fig. 11, seen facing the median ambulacral line.

,, 13. Magnified portion of test of fig. 11, seen facing the median interambulacral line.

,, 14. Magnified abactinal area of fig. 11.

,, 15. Jaws of large specimen magnified.

,, 16. Long, slender- pedicellarise among the primary radioles of test, magnified.

,, 17. Short, spherical pedicellariae, mainly found in space adjoining the bare part of

the abactinal region of the median interambulacral space, magnified.
,, 18. The opposite view of fig. 17.
,, 19 a, h, c, d. Difi"erent forms of straight, primary radioles, mainly from the actinal

edge of the test, and below the equatorial line of test ; all natural size

except d (f ).
,, 20 a, h, c. Different forms of radioles, from the actinal side (f ),
,, 20 d and 21 d are small radioles, closely packed near abactinal region of test in both

areas (f ).
,, 21 a, b, c. Different radioles from the actinal region of test ; all natural size except

,, 22 a, h, c. Primary curved radioles, mainly from the equatorial region of test ;

natural size.
a' c are figures of a and c seen from above, to show the triangular shape of the

shaft of the radioles.
„ 22 d. Radiole, with flattened shoe, found near actinal edge of the test (f ), similar to

that of the Arbaciadse.

PLATE VP.

Echinus horridus, A. Ag. (figs. 1-5), p. 115.

Fig. 1. Abactinal system (f).
„ 2. Part of side of test to show the size of the spines ; natural size.

EEPOET ON THE ECHINOIDEA. 283

Fig. 3. Coronal plates of abactinal surface near lower part of test (f ).
„ 4. Coronal plates of actinal surface (f-).
„ 5. Coronal plates of abactinal surface, somewhat above the plates of fig. 3 (f).

Micropyga tuherculata, A. Ag. (figs. 6, 7), p. G8.
„ 6. Abactinal system of young specimen, measuring 8 mm. {^^).
„ 7. Actinal system of same (i?).

Trigonocidaris monolini, A. Ag. (figs. 8-10), p. 111.

„ 8. Actinal system of specimen measuring 8 mm. in diameter {'^^).
„ 9. Abactinal system of same (ij2).

„ 10. Plates of the abactinal surface of the test immediately above the ambitus of
same.

Prionechinus sagittiger, A. Ag. (figs. 11 14), p. 109.

„ 11. Specimen measuring 7 mm. in diameter, covered with spines, seen from the

abactinal side.
„ 11 a. Magnified primar}^ spine.
„ 12. Actinal system of same (\2).
,, 13. Abactinal system of same.
„ 14. Coronal plates of test above ambitus of same.

Cottaldia forhesiana, A. Ag. (figs. 15-17), p. 112.

,, 15. Coronal plates of test above ambitus, same as fig. 16.

,, 16. Abactinal system of specimen measuring 17 mm. in diameter.

,, 17. Magnified primary spine.

PLATE VII.

Micropyga tubercidata, A. Ag. (figs. 1-9), p. 68.

Fig. 1. Seen from the abactinal pole ; natural size.
„ 2. Same, seen from the actinal side.
,, 3. Magnified view of the actinal cuts.
„ 4. Magnified view of portion of interambulacral and ambulacral zones of the actinal

side.
„ 5. Magnified view of portion of iuterambulacraland amlmlacral zone of the abactinal

side.
„ 6. Magnified view of denuded abactinal system.

284 THE VOYAGE OP H.M.S. CHALLENGER.

Fig. 7. Interambulacral and ambulacral zones of a smaller specimen (natural size) from
the abactinal side.
„ 8. Same, seen from the actinal side.
„ 9. Abactinal system of same specimen magnified.

PLATE VIII.

Aspidodiadema tonsiim, A. Ag. (figs. 1-9), p. 6G.
Fig. 1. Seen from the abactinal side (f ).
„ 2. Same species seen in profile, slightly enlarged.
„ 3. Same as fig. 2, seen from the actinal side, slightly enlarged.
„ 4. Denuded specimen, measuring 16mm. in diameter, seen from the abactinal

pole, to show the anal plates.
,, 5. Same, as fig. 4, seen in profile.

,, 6. Anal system of another specimen, showing anal plates covered with miliary spines.
7. Enhirged actinostome of fig. 1.

jj

8. Enlarged view of fig. 5, facing the median interambulacral line.

„ 9. Enlarged view of same facing the median ambulacral line.

Aspidodiadema microtuberculatum, A. Ag. (figs. 10-16), p. 65.

10. Profile of a specimen covered with spines ; natural size.

11. Enlarged view from actinal side, denuded (26 mm. in diameter).

12. Same, seen from the abactinal pole.

13. Enlarged view of genital ring.

14. Enlarged view of actinostome.

15. Enlarged view of actinostome actinal membrane denuded to show the size of

the buccal plates.
„ 16. Enlarged view of primary interambulacral tubercles, with a portion of the
included ambulacral area.

PLATE IX.

Phormosoma luculentum, A. Ag. (figs. 1-2), p. 97.
Fig. 1. Seen from above ; natural size.
,, 2. Seen in profile.

PLATE X.

Phormosoma luculentum, A. Ag. (figs. 1-4 a,h,c), p. 97.
Fio;. 1. Seen from the actinal side ; natural size.

REPORT ON THE ECHINOIDEA. 285

Fig. 2. Abactinal system of same, somewhat enlarged.

,, 3. Actinal system of same, somewhat enlarged.

,, 4 a. Tip of spine from the actinal side to show the shape of shoe, enlarged. 4 h. The
same seen from the side of the shoe. 4 c. Another spine, with differently-
shaped shoe, seen from the side.

PLATE X'\

Plexirechinus hothryoides, Ag. (figs. 1, 2), p. 108.
Fig. 1 . Abactinal system of specimen measuring 1 8 mm. in diameter.
,, 2. Enlarged view of part of sides of the test of same specimen.

Phormosoma luculentum, A. Ag. (figs. 3-7), p. 97.

,, 3. Denuded segment of test from the abactinal side.

,, 4. View of actinal segment of same specimen.

,, 5, 6. Sheathed spines, similar to those of A. grubii, from the abactinal part of the

test close to the apical system.
,, 7. One of the large peclicellarise of the actinal surface of the test.

Astropyga radiata, Gray (figs. 8, 9).

„ 8. Interior view of interambulacral plates of the actinal side, showing the deep pits
of the base of the primary tubercles.

,, 9. Interior view of interambulacral plates of the actinal plates, showing the lapping
of the edges and the two plates which make up each half of the inter-
ambulacral zone at that point.

PLATE X\

Phormosoma hursarium, A. Ag. (figs. 1-9), p. 99.

Fig. 1. Seen from the abactinal side ; natural size.
,, 2. Same, seen from the actinal side.

,, 3. Denuded portion of actinal surface of the test and actinostome of same.
,, 4. Abactinal system and denuded portion of the abactinal surface of same.
„ 5. Ambulacral and interambulacral plates of abactinal surface of same about one-
third from the edge of the test (-f ).
,, 6. Plates of actinal surface of test about one-third from the edge of the test (f ).
,, 7. Plates from the very edge of the test, showing the accumulation of miliaries

forming a rudimentary fasciole (f ).
,, 8. Enlarged view of the abactinal system (f ).

286 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 9. One of the pedicellarise which arc common along the edge of the test along the
line of the miliaries.

PLATE XL

Phormosortia hoplacantha, Wy. Thom. (figs, 1-4), p. 10 L

Fig. 1. Segment of test seen from the abactinal side ; half natural size (312 mm. in

diameter).
„ 2. Segment of same seen from the actinal side.
„ 3. Abactinal system covered with spines.
,, 4. Part of abactinal system denuded, to show the large anal plates separating the

plates of the genital ring (2).

PLATE XIL

Phormosoma hoplacantha, Wy. Thom. (figs. 1-4), p. 101.

Fig. 1 . Half of test seen in profile ; same specimen as that figured on Plate XL (half

natural size).
,, 2. Segment of test seen with the actinal floor removed, to show the position of the

ovaries and of the mesenteries separating the ovaries from the poriferous

zone.
„ 3. Same, seen from the interior to show the mode of imbricating of the buccal plates ;

they la]D away from the actinostome (f ).
,, 4. Part of actinal system denuded to show the arrangement of the buccal plates (f ).

PLATE XIP.

Young Echinothuridse (figs. 1-9), p. 71.
Fig. 1. Phormosoma rigid urn, A. Ag., seen from abactinal side (^^).
,, 2. Abactinal system of same still further enlarged (f).
,, 3. Segment of actinal surface of test of same (f ).
,, 4. Segment of abactinal surface of test of same (f ).
,, 5. Abactinal system and segment of test of young Asthenosoma gracile, A. Ag. (f ),

24 mm. in diameter.
,, 6. Segment of actinal surface of same.

„ 7. Abactinal system oi Phormosoma asterias, measuring 30 mm. in diameter (f).
,, 8. Segment of actinal surface of same (f ).
„ 9. Segment of abactinal surface of same (f).

REPORT ON THE ECIIINOIDEA. 287

Phormosoma hoplaca7itha, Wy. Thorn, (figs. 10-13), p. 101
Fig. 1 0. Segment of actinal surface near ambitus ; natural size.
„ 11. Same jjlates, seen from the interior of the test.
„ 12. Plates from the abactinal surface near ambitus seen from the interior, slightly

enlarged.
„ 13. Same plates, seen from the abactinal surface.

Asthenosoma tessellatum, A. Ag. (figs. 14, 1.5), p. 88.
„ 14 Coronal plates of actinal surface near ambitus (^*-^).
,, ] 5. Coronal plates of abactinal surface near ambitus (i^).

PLATE XIII.

Phormosmna tenue, A. Ag. (figs. 1, 2), p. 91.
Fig. 1. Seen from the abactinal side with spines.
„ 2. Same, seen in profile.

Both figures natural size.

PLATE XIV.

Phormosoma tenue, A. Ag. (figs. 1-4), p. 91.
Fig. 1. Interior of the abactinal part of the test to show the ovaries, the large ambu-

lacral tubes, and the indistinct division into secondary plates of the large

primary plates of both areas ; natural size.
„ 2. Interior view of the actinal part of the test, showing the course of the alimentary

canal, the mesenteric loops m, m arching over the ambulacral system, and

the large ambulacral tubes a with the tubes extending at right angles from

it to the ambulacral vesicles a'.
,, 3. Magnified view of the abactinal system.
„ 4. Magnified view of the actinal system.

PLATE XV.

Asthenosoma gruhii, A. Ag. (figs. 1, 2), p. 82

Fig. 1. Seen from the abactinal side ; natural size.
,, 2. Same, seen in profile.

'&•

288 THE VOYAGE OF H.M.S. CHALLENGER.

PLATE XVI.

Asthenosoma grubii, A. Ag. (figs. 1-13), p. 82.

Y'lSf. 1 . Seen from the actinal side ; natural size.

2. Short spine with membraneous sheath from the abactinal surface of fig. 1, Plate
XV., enlarged.

3, 4. Longer spines with membraneous sheaths.
5. Short, sharp miliary spine.
6 a, b, c. Different parts of spine (fig. 4) without membraneous sheath.

7. Short spine with club-shaped membraneous sheath at tip.

8. Another spine of same kind as fig. 7.

9. Same spine, different view.

10. Large short-stemmed pedicellaria of actinal surface.

11. Small-headed, long-stemmed pedicellaria of the abactinal surface.

1 2. Long-stemmed trifid pedicellaria of the actinal surface.

13. Somewhat smaller pedicellaria of same kind as fig. 12, expanded.

. PLATE XVIL

Asthenosoma grubii, A. Ag. (figs. 1-6), p. 82.
Segment of test seen from the actinal side, denuded of spines ; natural size.
Denuded segment of the test, abactinal side, natural size.
Magnified view of abactinal system.
Magnified view of actinal system.
Portion of the ambulacral system, abactinal side.

Portion of the ambulacral system, actinal side. The tubercles on figs. 1 and 2
are for the greater part pei'forated.

PLATE XVIP.

Asthenosoma gracile, A. Ag. (figs. 1-4), p. 89.

Fig. 1. Seen from the abactinal surface ; natural size.

2. Abactinal system denuded (f ).

3. Coronal plates of actinal surface near the ambitus (f ).

4. Coronal plates of the abactinal surface near the ambitus (f).

Asthenosoma coriaceum, A. Ag. (figs. 5-7), p. 88.

5. Denuded abactinal system of specimen measuring 212 mm. in diameter; natural

size.

Fig.

1.

2.

3.

4.

5.

6.

&■

REPOET ON THE ECHINOIDEA. 289

Fig. 6. Ambulacral and interambulacral plates of abactinal surface of same specimen
near^ambitus (^-5-).
„ 7. Ambulacral and interambulacral plates of actinal surface of same near
ambitus (i^).

Fhoi^mosoma tenue, A. Ag. (fig. 8), p. 91.
„ 8. Abactinal system of specimen measm-ing 127 mm, (f).

PLATE XVIII.

Asthenosomcc pellucidnm, A. Ag. (figs. 1-6), p. 85.

Fig. 1. Segment of test of specimen from tlie actinal side, measuring 37 mm. in
diameter (f ).

„ 2. Same, seen from the abactinal side.

■ „ 3. Abactinal system of same (f).

„ 4. Segment of test of specimen measuring 59 mm., seen from the actinal side (f ).

,, 5. Same, seen from the abactinal side.

,, 6. Abactinal system of same (f ).

Phormosoma tenue, A. Ag. (figs. 7-9), p. 91.

,, 7. Segment of test of specimen measuring 90 mm., seen from the abactinal side (f).
„ 8. Same, seen from the actinal side.
„ 9. Abactinal system of same (J).

PLATE XVIIP.

Phormosoma tenue, A. Ag. (figs. 1-13), p. 91.

Fig. 1. Portion of test of specimen, measuring 145 mm., adjoining ambitus of abactinal

surface (i^).
,, 2. Denuded portion of test of abactinal surface of same, near abactinal system.
,, 3. Denuded portion of actinal surface of test of same, near ambitus.
,, 4. Interior view of preparation of abactinal surface, showing subdivisions of coronal

plates; specimen measuring 131 mm. (f).
,, 5. Interior view of actinal surface, not cleaned (f ).
„ 6. Main amljulacral tube, with lateral branches leading to ampuUse, actinal

surface (|~).
,, 7. Interior view of abactinal part of test, median part (f ).
,, 8. Interior view of abactinal part of test, preparation (f).
,, 9. Actinal part of test, median part (f ).

(ZOOL. CHALL. EXP. — PART IX 1881.) I 37

290 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 11-13. Greatly enlarged views of pedicellarise.

,, 11. Pedicellaria of the abactinal part of test.

,, 12. One of the pedicellariae of actinal surface.

,, 13. One of the trifid abactinal pedicellariae.

Asthenosoma peUucidum, A. Ag. (figs. 3o, 14-17), p. 85.
,, 13 a. Denuded portion of abactinal surface of test, median part (f).
„ 14. Portion of abactinal part of test of specimen, measuring 37 mm.
,, 15. Portion of the actinal side of test of same (f).

,, 16. Portion of the abactinal side of test of larger specimen, measuring 59 mm, (^).
„ 17. Portion of the actinal side of test of same specimen as fig. 16 (f).

PLATE XVIII^

Phormosoma temie, A. Ag. (figs. 1-13), p. 91.
Fig. 1 . Interior view of aliactinal system of specimen, measuring 133 mm. in diameter (^).
„ 2. Same, seen from the exterior.
,, 3. Segment of actinal membrane seen externally {^).
,, 4. Actinal system seen from the interior, showing the extension of the main ambu-

lacral tubes and the position of the auricles, jaws removed (f).
,, 5. Same, with the jaws in place.

„ 6. Slightly inclined view, showing the low and feeble auricles.
,, 7. Jaws, seen in profile (f ).
,, 8. Single jaw, seen from inside.
,, 8 a. Same, in profile.

,, 9, 9a, 96. Different pieces of the support of the jaws.

,, 10. Part of main ambulacra! tube with lateral branches, abactinal side (f).

„ 11. Same near the ambitus (f).

,, 12. Portion of abactinal surface of test, adjoining the abactinal system (-^).

,, 13. Portion of actinal sm-face of test, adjoining the ambitus (f ).

PLATE XVIIP.

Phormosoma luculentum, A. Ag. (figs. 1-4), p. 97.

Fig. 1. Young specimen, measuring 18 mm. in diameter, seen from the actinal side,
,, 2. The same, seen from the abactinal side.
„ 3, Abactinal system and segment of abactinal surface of somewhat older specimen,

measuring 36 mm. in diameter.
„ 4. Segment of actinal surface of same specimen.

REPORT ON THE ECHINOIDEA. 291

PhormoswiKt tenite, A. Ag. (figs. 5-9), p. 91.
Fig. 5. Abactinal system and segment of abactinal surface of young specimen, measuring
18 mm. in diameter (f).
,, 6. Abactinal system and segment of abactinal surface of young specimen, measuring

49 mm. in diameter.
„ 7. Actinal system and segment of actinal surface of same specimen as fig. 6.
„ 8. Coronal plates, near ambitus, of specimen measuring 90 mm. in diameter, from

the abactinal surface.
,, 9. Coronal plates of actinal surface near ambitus of same specimen as fig. 8.

Micropyga tuherculata, A. Ag. (figs. 10, 11), p. G8.
„ 10. Young specimen, measuring 7 mm, in diameter, seen from the abactinal

surface.
„ 11. Same, seen from the actinal side.

Phorinosoina uranus, Wy. Thom., p. 103.
„ 12. Actinal system and segment of actinal surface of young specimen, measuring
8 mm. in diameter (f ).

PLATE XIX.

Asthenosoma pellucidum, A. Ag. (figs. 1-6), p. 85.

Fig. 1 . Young specimen, seen from the actinal side ; natural size.

2. Same specimen, seen from the abactinal side.

3. Same, seen in profile.

4. Somewhat larger specimen, seen from the actinal side.

5. Same specimen, seen from the abactinal side.

6. Same, seen in profile.

Phormosoma tenue, A. Ag. (figs. 7-9), p. 91.
,, 7. Young specimen, seen from the abactinal side.
„ 8. Same, seen from the actinal side.
„ 9. Same, seen in profile.
By mistake of the draughtsman the profile figures are all represented with the actinal
surface uppermost.

All figures natural size.

292 THE VOYAGE OF H.M.S CHALLENGER.

PLATE XIX^

Asthenosoma tessellatum, A. Ag. (fig. 1), p. 88.
Fig. 1. Seen from the actinal side; natural size.

Phormosoma tenue, A. Ag. (fig. 1), p. 91.
„ 2, Seen from the actinal side ; natural size.

PLATE XIXi\

Asthenosoma tessellatum, A. Ag. (figs. 1-4), p. 91.
Fig. 1. Seen in jDrofile.
,, 2. Same, seen from the abactinal side ; natural size.
„ 3. Abactinal system of same, denuded (f ).

,, 4. Magnified portion of ambulacral area, to show the pointed tentacles of the
abactinal system (f ).

PLATE XX.

Hemiaster zonatus, A. Ag. (figs. 1-4), p. 186.

Fig. 1. Hemiaster zonatus, seen from the abactinal side ; natural size.

2. Same, seen from the actinal side.

3. Same, seen from the anal extremity.

4. Same, seen in profile.

Hemiaster gibhosus, A. Ag. (figs. 5-16, 22), p. 184.

5. Hemiaster gibhosus, denuded, seen from the abactinal side (f ).

6. Same, seen from the actinal side.

7. Same, seen in profile.

8. Sam e,seen from the anal extremity.

9. Magnified view of half the petaloid ambulacra.

10. Magnified view of portion of the side of the test adjoining lateral ambulacra.

11. Magnified view of abactinal system.

12. Group of spines and pediceUarite, from the actinal side.

13. Granular tubcrculation of miliaries.

14. 15. Club-shaped spines near actinostome.
16. Ambulacral sucker near the actinostome.
22. Suckers from the lateral petaloid ambulacra.

'&•

REPORT ON THE ECHINOIDEA. 293

Catojyi/gus recens, A. Ag. (figs. 17-21), p. 123.

Fig. 17. Petaloid ambulacra of Catopygus recens (■^^)-

„ 18. Catojyi/gus recens, seen from the abactinal side ; natural size.

„ 19. Same, seen from the actinal side.

„ 20. Same, seen from the anal extremity.

,, 21. Same, seen in profile.

PLATE XX^

Hemiaster cavernosus, A. Ag. (figs. 1-22), p. 177.

Fig. 1. Female, seen from the abactinal side, showing the mode of carrying the young

in the deeply-sunken petaloid ambulacral areas.
„ 2. Single petal, with the young less advanced than in fig. 1 (f ).
,, 3. Test, seen from the actinal side (large male).
„ 4. Large male, seen from the abactinal side, to show the petaloid ambulacra slightly

sunken below the general level of the test.
Figs. 1, 3, 4, all somewhat enlarged {^)-
„ 5. Interior view of abactinal part of test, showing the narrow, slightly swollen

petaloid ambulacra of a male ; natural size.
„ 6. Same view of a female, showing the broad, swollen petaloid ambulacra ; natural

size.
„ 7. Young Hemiaster, taken from the pouch of the petaloid ambulacra, still some-
what circular with straight primary spines, seen from the abactinal pole ;

natural size, 2 mm.
„ 8. Somewhat older Hemiaster, with curved primary spines, seen from the abactinal

pole ; natural size, 3 mm.
„ 8 a. Three spines of fig. 8 ; magnified.
„ 9. Young Hemiaster. about in condition of fig. 8, denuded of spines, showing the

simple ambulacral pores, the large anal opening within the peripetalous

fasciole, and the ring of large primary tubercles, forming its imier edge ;

magnified.
„ 10. The same, somewhat less magnified, seen from the actinal side.
„ 11. Section through a young lZem{as^er of about this stage, showing the course of

the alimentary canal.
„ 12. Magnified view of portion of the test of fig. 9, showing a part of the ambulacral

and interambulacral systems and a piece of the peripetalous fasciole.
„ 13. Young Hemiaster, measuring 5-5 mm. ; the anal system is just beyond the edge

of the broad peripetalous ftisciole, seen from the abactinal side.

294 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 14. Somewhat older stage than fig. 3, seen from the same side of the test, measur-
ing 8 mm.

15. Still older stage, measuring 9 mm. First appearance of the genital plates.

16. Somewhat more advanced than fig. 15, measuring 11 mm.

17. Older than fig. 16, measuring 12 mm.

18. Older than fig. 17, measuring 15 mm.

1 9. Female (abactinal side) with deeply-sunken, broad petaloid ambulacra, and two
genital pores ; natural size.

20. Female with narrower, deeply-sunken petaloid ambulacra, and three genital
pores ; natural size.

Figs. 19 and 20 are not fully grown.

21. Abactinal system of large male ; magnified.

22. Abactinal system of large female ; magnified.
The largest specimen measuring 50 mm. in longitudinal diameter.

PLATE XXI.

Breynia australasice, Gray (figs. 1, 2), p. 177.

Fig. 1. Seen from the actinal side ; natural size.

„ 2. Seen from the abactinal side ; natural size.

Palceotwpus loveni, A. Ag. (figs. 3-16), p. 158.

„ 3. Enlarged view of denuded specimen, seen from the abactinal side (f).

„ 4. Same, seen from the actinal side.

„ 5. Same, seen in profile.

,, 6. Same, seen facing the anterior extremity.

,, 7. Same, seen facing the anal system.

,, 8. Enlarged view of anal system and of subanal fasciole.

„ 8 a. Plates of actinostome.

„ 9. Profile view of Palwotropus loveni; natural size, with its spines.

,, 10. Same, seen from the actinal side.

,, 11. Same, seen from the abactinal side.

,, 12. Abactinal system, seen from the interior of the test.

,, 13. Abactinal system, denuded.

,, 14. Actinostome, seen from the interior of the test.

,, 15. Denuded actinostome.

,, 16. Enlarged view of primary and secondary tubercles from the actinal surface.

REPORT ON THE ECHINOIDEA. 295

PLATE XXII.

Pourtalesia phiale, Wy. Thorn, (figs. 1-5), p. 138.
Fig. 1. Seen from the actiual side (f).
„ 2. Profile view of same.
„ 3. Seen from the abactinal side.
,, 4. Seen facing the actinal extremity.
„ 5. Seen facing the anal extremity.

Pourtalesia hisjnda, A. Ag. (figs. 6-19), p. 136.
„ 6. Profile view of Pourtalesia hispida (i^).
„ 7. Same, seen from the abactinal side.
„ 8. Same, seen from the actinal side.
„ 9. Enlarged profile view of anal extremity.
„ 10. Interior profile view of test, to show course of the anterior part of the alimentary

canal and the genital organs.
„ 11. Interior profile view, showing the position of the posterior portion of the

alimentary canal ; natural size.
,, 12. End view facing the anal extremity (^^).
„ 13. End view of same, facing the actinal extremity.
„ 14. Interior view of anal extremity, seen from above.
„ 1 5. Interior view of actinal groove, seen in profile.
,, 16. Exterior view of actinal groove, seen from below.
„ 17. Interior view of actinal groove, seen from below.
,, 18. Interior view of abactinal system, showing position of ovaries.
„ 19. Interior view of abactinal system, showing the bivium and trivium.

PLATE XXII

Pourtalesia phiale, Wy. Thom. (figs. 1, 2), p. 138.
„ 1. Seen in profile (denuded), enlarged (f).
„ 2. Seen from the actinal side (denuded), enlarged.

Pourtalesia rosea, A. Ag. (figs. 3-6), p. 139.

,, 3. Anal snout, seen in profile (f), actinal surface uppermost.

„ 4. Anal snout, seen from the actinal side.

„ 5. Same, seen from the abactinal side.

„ 6. Interior view of abactinal svstem.

'ig-

7.

8.

9.

10.

11.

12.

13.

14.

296 THE VOYAGE OF H.M.S. CHALLENGER.

Pourtalesia lagmicula, A. Ag. (figs. 7-15), p. 137.

7. Seen in profile, denuded (f ).
Same, seen from the actinal end.
Same, seen from the actinal side.
Interior view of the abactinal system.

Three interambulacral plates from the median part of the test.
Interior view of anterior jjart of test, to show Hoffman's organ.
Interior view of anal extremity of test.
One of cluster of genital organs.

PLATE XXIII.

Cionobrissus revinctus, A. Ag. (figs.1-12), p. 188.

Fig. 1. Seen in profile denuded; natural size.

,, 2. Seen from the abactinal side, covered with spines.

„ 3. Same, seen from the actinal side.

„ 4. Same as fig. 1, seen facing the anal extremity.

,, 5. Same as fig. 1, seen facing the anterior extremity.

,, 6. Petals and surrounding peripetalous fasciole.

„ 7. Magnified view of posterior extremity, seen in profile.

,, 8. Interior view of actinostome.

„ 9. Exterior view of actinostome denuded.

, , 10. Profile view of course of alimentary canal.

,, 11. Actinal view of same.

„ 1 2. Abactinal view of same.

PLATE XXIV.

Homokmipas fulva, A. Ag. (figs. 1-12), p. 164.

Fig. 1. Seen in profile, denuded ; natural size.

2. Same, seen from the abactinal side, one-half of test covered with spines.

3. Same, seen from the actinal side.

4. Enlarged view of posterior extremity, showing anal system and subanal fasciole.

5. Interior of anal part of test, showing termination of alimentary canal.

6. Interior view of apical system, sho'ndng the four ovaries.

7. Interior view of apical system, showing the four genital openings.

REPORT ON THE ECHINOIDEA. 297

Fig. 8. Interior view of apical portion of test, showing the purse-like pouches under the

large Lovenia-like primary spines.
„ 9. Magnified portion of the actinal surface of the posterior interambulacral area.
„ 10. Interior view of pouched rings corresponding to the primary tubercles of the

actinal surface.
„ 11. Magnified view of actinostome.
„ 12. Magnified view of the apical system.

PLATE XXV.

Zdnopneustes (Paleopneustes) murrayi, A. Ag. (figs. 1-9), p. 168.

Fig. 1. Test partly denuded, partly covered with spines, seen from the abactinal side ;
natural size.

2. Same, seen from the actinal side.

3. Same, seen in profile.

4. Same, seen facing the anal system.

5. Abactinal system, magnified.

6. Magnified view of anal system, and of subanal fasciole.

7. Magnified view of actinostome and of surrounding plates.

8. Interior view of apical system, and of tubes leading to genital organs and to
limestone canal.

9. Magnified view of part of one of the ambulacral tubes and plates adjoining the
actinostome.

PLATE XXVI.

Spatagocystis challenger i, A. Ag. (figs. 1-11), p. 141.

Fig. 1. Seen in profile.

„ 2. Same, seen from the actinal surface.

„ 3. Same, seen from the abactinal side.

„ 4. Same, seen facing the anterior extremity.

„ 5. Same, seen facing the anal extremity.

„ 6. Profile view, showing course of alimentary canal.

„ 7. Profile view of smaller specimen.

„ 8. Same, seen from the actinal side.

„ 9. Same, seen from the abactinal side.

„ 10. Same, seen facing the anal extremity.

(ZOOL. CHALL. EXP. — FART IX. 1881.) I 38

298 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 11. Same, seen facing the anterior extremity.
All figures natural size.

PLATE XXVJa.

Spatagocystis challengeri, A. Ag. (figs. 1-17), p. 141.

Fig. 1. Interior view, slio-^vdng course of alimentary canal, seen from the actinal side.
„ 2. Portion of test showing the arrangement of the plates surrounding the right

anterior part of the actinal surface, magnified.
,, 3. Magnified view of actinal groove, covered with spines.
,, 4. Actinal view of part of the test, showing the arrangement of the plates along the

median part of the actinal surface, and posterior part of the actinal groove.
,, 5. Interior view of the pouch forming the anal system.
„ 6. Interior profile view of pouch, and termination of intestine in the posterior end

of the pouch.
„ 7. Abactinal view of anal snout ; test projecting over this removed.
,, 8. Magnified view of abactinal system and surrounding plates.
,, 9. Interior view of apical part of lateral anterior and posterior ambulacra, and the

enclosed lateral interambulacrum and adjoining ambulacrum.
,, 10. Interior view of part of the abactinal median ridge (the pores should be in the

outer plates) ; the median rows of plates are the interambulacral plates. See

fig. 17.
„ 11. Interior view of the posterior part of the actinal surface, showing the course of

the lateral posterior ambulacra, and arrangement of the plates forming the

base of the anal snout.
,, 12. Same, seen from the actinal side, showing the large tuberculatiou forming the

keel of the actinal plastron.
,, 13. Profile view of anal snout.
,, 14. Exterior view of part of test of anterior lateral ambulacra and adjoining inter-

amlDulaera, showing the uniformity of the tuberculatiou.
„ 15, 16. Two views of the posterior extremity of test, seen in profile, one shaded to

show the tuberculatiou, the other to show the arrangement of the plates and

course of the aml:)ulacral pores.
,, 17. Posterior extremity of the test, seen from the abactinal side, showing the

arrangement of the plates and course of the lateral posterior ambulacra! tubes.
Fig. 1, natural size ; aU others somewhat magnified.

REPORT ON THE ECHINOIDEA. 299

PLATE XXVII.

Echinocrepis cuneata, A. Ag. (figs. 1-11), p. 145.

Fig. 1. Seen from the abactinal side, covered with spines.
,, 2. Same, seen from the actinal side.

,, 3. Same, seen in profile.

„ 4. Same, seen facing the anal extremity.

,, 5. Same, seen facing the anterior extremity.

,, 6. Interior view, seen from the actinal side, showing the course of the alimentary

canal.

„ 7. End view of anterior part of test, denuded.

„ 8. Tuberculation of interambulacral plates of the median abactinal side of test.

„ 9. Magnified view of apical system and surrounding j^lates.

„ 10. Anal system, seen from the actinal side.

„ 11. Hofiman's organ in Echinocrepis.

Figs 1-6, natural size ; all others somewhat enlarged.

PLATE XXVIIL

Pourtalesia ceratopyga, A. Ag. (figs. 1-12), p. 134.

Fig. 1. Seen from the abactinal side, covered with spines ; natural size.

„ 2. Same, seen in profile.
,, 3. Same, seen facing the anterior extremity.
,, 4. Same, seen facing the anal extremity.

,, 5. Interior view, showing general course of the alimentary canal.

„ 6. Actinal view of anterior part of test, denuded.

,, 7. Actinal view of posterior extremity of test.
„ 8. Actinal view of a smaller specimen (same as fig. 6).

,, 9. Abactinal view of anterior part of test of fig. 8.

„ 10. Interambulacral plates of test to show the regular tuberculation.

,, 11. Interior view of abactinal part of test.

„ 12. Abactinal system denuded.

PLATE XXVIIP.

Pourtalesia caiinata, A. Ag. (figs. 1-15), p. 133.
Fig. 1. Seen from the abactinal side ; natural size.

300 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 2. Same, seen in profile.

,, 3. Magnified portion of the posterior extremity, denuded, seen in profile.
,, 4. Anal snout, seen from the actinal side, denuded.
,, 5. Anal snout, seen from the abactinal side, covered wdth spines.
„ 6. Anal extremity, showing snout, and the connection of intestine with anal system.
,, 7. End view of the anal snout.

,, 8. Actinal groove and portion of actinal surface surrounding it, covered with spines.
,, 9. Interior view of actinostome, with adjoining plates, forming the actinal groove.

,, 10. Actinal edge of actinal groove, showing the plates adjoining it.

,, 11. Profile of actinal groove, seen from the interior.

,, 12. Abactinal system denuded.

,, 13. Interior view of abactinal part of test, with genital organs.

,, 14. Interior view of apical part of lateral anterior ambulacra.

,, 15. Large primary spines of the rounded keel, forming edges of anterior part of test.

PLATE XXIX.

Urechinus naresianus, A. Ag. (figs. 1-4), p. 146.

Fis;. 1. Seen from the abactinal side of the test.

2. Same, seen in profile.

3. Same, seen from the actinal side.

4. Same, seen facing the anal extremity.

Cystechinus tvi/villii, A. Ag. (figs. 5-8), p. 152.

5. Seen in profile.

6. Same, seen facing the odd anterior ambulacrum.

7. Same, seen from the abactinal side.

8. Same, seen from the actinal side.
All figures natural size.

PLATE XXIX*.

Cystechinus wyviUii, A. Ag. (figs. 1-20), p. 152.

Fig. 1. Young specimen, measuring 16 mm., seen from the abactinal side.

,, 2. Same, seen from the anal extremity.

„ 3. Same, seen from the actinal side.

,, 4. Same, seen in profile.

'■o'

REPOET ON THE ECHINOIDEA. 301

Fig. 5. Somewhat older thau figs. 1-4, measuring 22 mm., seen from the ahactiual side.
,, 6. Same, seen from the actiual side.
,, 7. Same, seen in profile.
,, 8. Same, seen facing the anal extremity.

,, 9. Still older specimen, measuring 39 mm., seen from the abactinal side.

„ 10. Same, seen from the actinal side.

,, 11. Same, seen facing the anal extremity.

,, 12. Same, seen in profile.

„ 11'. Abactinal system and surrounding plates of specimen, measuring 16 mm.

,, 12'. Abactinal system and surrounding plates of specimen, measuring 39 mm.

,, 13. Interior view of apical system and genital organs of imperfect specimen,

measuring about 50 mm.

,, 14. Exterior view of apical system and surrounding plates (same as fig. 13).

„ 15. Interior view of actinal system of imperfect specimen, measuring about 35 mm.

„ 16. Exterior of same as fig. 16.

,, 17. Interior view of actinal system of specimen, measuring about 25 mm.

,, 18. Exterior view of same as fig. 17.

,, 19. Interior view of anal system and termination of intestine of specimen measur-

ino- about 35 mm.

„ 20. Exterior view of anal system of same as fig. 19.

PLATE XXIX^

Cystechinus ivyvillii, A. Ag. (figs. 1-9), p. 152.

Fig. 1. Abactinal view of test, denuded ; natural size.
,, 2. Same, seen from the actinal side.
,, 3. Same, seen in profile.
,, 4. Same, seen facing the anal extremity.
„ 5. Magnified view of plates surrounding the actinostome.
,, 6. Interior view of same as fig. 5.
,, 7. Interior view of the apical part of one of the lateral anterior ambulacra and

adjoining interambulaeral plates.
,, 8. Interior view from the actinal side, to show the course of the alimentary canal.
„ 9. Magnified view of one of the interambulaeral plates, to show the ridges and

tuberculation.

302 THE VOYAGE OF H.M.S. CHALLENGER.

PLATE XXX.

Urechinus naresianus, A. Ag. (figs. 1-24), p. 146.

Fio-. 1. Young specimen, measuring 27 mm., seen from the abactinal side,
„ 2. Same, seen in profile.
„ 3. Same, seen from the actinal side.

4. Somewhat younger specimen, measuring 18 mm., seen from the abactinal side.
„ 5. Same, seen in profile.
„ 6. Same, seen facing the anal extremity.
„ 7. Another specimen, measuring 16 mm., differing somewhat in outline, seen from

the abactinal side.
„ 8. Younger specimen than fig. 4, measuring 15 mm., seen from the abactinal side.
,, 9. Same, seen in profile.
,, 10. Same, seen from the actinal side.

„ 11. Still younger specimen, measuring only 13 mm., seen from the abactinal side.
,, 12. Same, seen from the actinal side.
,, 13. Same, seen in profile.

14. Exterior view of actinostome and surrounding plates of specimen measuring
46 mm.
,, 15. Interior view of same.

„ 16. Abactinal system and surrounding plates of specimen measuring 46 mm.
„ 17. Interior view of apical system and sm-rounding plates of specimen measuring

46 mm.
„ 18. Interior view of anal system and portion of adjoining ambulacral areas.
„ 19. Anal system and indistinct subanal fasciole.

„ 20. Magnified primary spine, from the edge of ambitus of specimen measuring 40 mm.
,, 21. Miliary spine of same.

22. Trifid elongate pedicellaria, with slender-stemmed articulation.
„ 23. Club-shaped pedicellaria, wdth heavy-stemmed articulation, seen in profile.
„ 24. Head of same, seen from above.

PLATE XXX^.

Urechinus naresianus, A. Ag. (figs. 1-14), p. 146.
Fig. 1. Conical individual, seen from the abactinal side (f ).

2. Same, seen from the actinal side.

3. Same, seen in profile.

REPORT ON THE ECHINOIDEA, ' 303

Fig. 4. Same, seen facing the odd anterior ambulacrum.
„ 5. Same, seen facing the anal system.
,, 6. Actinostome of same, enlarged.
,, 7. Normal UrecMnus naresiamis seen in profile {—).
„ 8. Same, seen from the abactinal side.
„ 8 a. Enlarged figure of abactinal system of same.
,, 9. Same, seen from the actinal side.

„ 10. Another specimen, with a subanal fasciole, measuring 48 mm., seen from the

actinal side.

,, 10 a. Anal system of same, with a subanal fasciole, enlarged.

„ 11. Same, seen from the abactinal side.

„ 12. Same, seen in profile, showing the blunt anal snout.

„ 13. Same, seen facing the posterior extremity.

,, 14. Same, seen facing the odd anterior ambulacrum.

Brissus damesi, A. Ag. (figs. 15, 16), p. 197.

,, 15. Part of test of specimen, measuring 22 mm., seen from the abactinal side.
„ 16. Anal system of same, showing rudimentary fasciole, enlarged.

PLATE XXXI.

Pourtalesia laguncula, A. Ag. (figs. 1-11), p. 137.

Fig. 1. Seen from the actinal side, specimen measuring 22 mm.

,, 2. Same, seen from the abactinal side.

,, 3. Same, seen in profile.

,, 4. Profile view of anal snout, greatly enlarged.

,, 5. Same as fig. 3, seen facing the anal extremity.

,, 6. Same, seen facing the anterior extremity.

„ 7. Younger specimen, measuring 12 mm., seen from the actinal side.

,, 8. Same, seen from the abactinal side.

,, 9. Same, seen in profile.

,, 10. Elong-ated anal snout of difierent specimen, of about same size as fig. 7, seen in

profile.

„ 11. Anal snout of another specimen, less elongate, measuring about 12 mm.

Genicopatagiis affinis, A. Ag. (figs. 12-22), p. 162.

„ 12. Seen from the actinal side, natural size.
,, 13. Same, seen from the abactinal side.

304 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 14. Same, seen in profile.

15. Same, seen facing the anal extremity.

16. Somewhat younger specimen, more circular in outline, seen from the abactinal
side ; natural size.

17. Same, seen from the actinal side of the test.

18. Same, seen from the end facing the anal system.

19. Same, seen in profile.

20. Still younger specimen, measuring 10 mm., quite angular in outline, seen from
the abactinal side.

21. Same, seen in profile.

22. Same, seen from the actinal side.

PLATE XXXII.

Argopatagxis vitreus, A. Ag. (figs. 1-6), p. 160.

Fig. 1. Seen from above ; natural size.

2. Same, seen from the actinal side.

3. Same, seen in profile.

4. End view of subanal fasciole, enlarged, abactinal side below.

5. Actinostome, with surrounding plates, enlarged.

6. Abactinal region of same enlarged.

Aceste beUidifera, Wy. Thom. (figs. 7-11), p. 195.

„ 7. Seen from the actinal side, enlarged (27 mm., u. s.).
,, 8. Same, seen from the abactinal side, still more enlarged.
„ 9. Same, seen facing the anterior extremity.
,, 10. Same, seen facing the anal extremity.
,, 11. Same, seen in profile.

Figs. 9, 10, 11 are drawn with the actinal side uppermost.

PLATE XXXIII.

Aerope rostrata, Wy. Thom. (figs. 1-13), p. 192.

Fig. 1. Seen from the abactinal side, measuring 43 mm.

„ 2. Same, seen from the actinal side.

,, 3. Same, seen in profile.

„ 4. Interior profile \'iew, showing the course of the alimentary canal.

REPORT ON THE ECHINOIDEA. 305

Fig. 5. Same seen facing the anal extremity.

„ 5'. Same as fig. 8, seen facing the anterior extremity.

,, 6. Enlarged view of large suckers of odd anterior ambulacrum of fig. 8.

,, 7. Anal system of fig. 8.

„ 8. Smaller specimen than fig. 1, measuring 20 mm., seen from the abactinal side.

,, 9. Same, seen from the actinal side.

,, 10. Same, seen in profile.

,, 11. Seen, facing the anal system, smaller than fig. 8.

,, 12. Same, seen facing the actinal extremity.

,, 13. Actinostome of fig. 9; magnified.

PLATE XXXIIK

Aceste hellidifera, Wy. Thorn, (figs. 1-7), p. 195.

Fig. 1. Seen from the abactinal side (f).

„ 2. Same, seen from the actinal side.

,, 3. Same, seen in profile.

„ 4. Same, seen from the posterior extremity.

„ 5. Same, seen from the anterior extremity.

„ 6. Enlarged view of actinostome of fig. 5.

„ 7. Enlarged view of apical system and adjoining ambulacra! area.

Aerope rostrata, Wy. Thom. (figs. 8-12), p. 192.

8. Seen from the actinal side (^).

9. Same, seen in profile.

10. Enlarged view of apical system and of abactinal part of test.

1 1 . Enlarged view of actinostome.

12. Enlarged view of anal system.

PLATE XXXIV.

Calymne relicta, Wy. Thom. (figs. 1-13), p. 155.

Specimen measuring 30 mm., copied in part from Thomson.

Fig. 1. Test, seen from the actinal side.
„ 2. Test, seen from the abactinal side
„ 3. Test, seen in profile.

„ 3 a. Cluster of paddle-shaped primary spines on the abactinal side of the edge of
the posterior part of test.

(ZOOL. CHALL. EXP. — PART IX. — 1881.) I 39

306 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 4. Eularged end view of test, showing course of lateral fasciole across the posterior
extremity.

5. Interior view of abactinal surface of test ; enlarged.

6. Interior view of actinal floor of test ; enlarged.

7. Interior view of actinostome ; enlarged.

8. Actinostome, seen from the actinal side ; enlarged.

9. Large primary tubercles of abactinal surface, adjoining apical system, in odd
anterior ambulacrum.

8 (should be 10). Abactinal part of test, extending from upper part of the odd
anterior ambulacrum to the cluster of primary spines in the median inter-
ambulacral space above the anal system between it and the apical system ;
enlarged.

11. Cluster of primary spines, placed above the anal system on the abactinal
extremity of the posterior part of the test. See fig. 3.

11 a, h, c, d, e,f. Differently shaped primary spines.

12. Anal system, protected by paddle-shaped primary spines round the abactinal
edge.

13. Shows the outline of the anal system, with the shape of the plates covering it.

Podocidaris prionigera, A. Ag. (figs. 14, 15), p. 59.

14. Part of ambulacral and interambulacral regions of test, seen from the abactinal
side, to show the relation of the primary and secondary tubercles adjoining
the ambitus ; enlarged.

15. Enlarged view of abactinal system.

PLATE XXXV.

Cystechinus vesica, A. Ag. (figs. 1-20), p. 150.

Fig. 1. Seen from the abactinal pole ; natural size.

„ 2. Same, seen in profile.

,, 3. Same, seen from the actinal side.

,, 4. Different specimen, showing shape assumed owing to extreme tenuity of test.

,, 5. Interior view, seen from actinal side, to show the course of the alimentary canal.

,, 6. Interior view of apical system and of genital organs.

7. View of genital organs of a different individual.

8. Actinostome, somewhat enlarged, covered with spines.

9. Anal system, exterior view.

REPORT ON THE ECHESTOIDEA. 307

Fig. 10. Interior view of anal system, with termination of intestine.

11. Interior view of actinostome and plates surrounding it.

12. Exterior view of actinal system and surrounding plates.

13. Interior view of actinal system, with the actinal termination of the ambulacral
tubes and vesicles.

14. Primary spine from the abactinal surface.

15. Club-shaped spine from the edge of the test.

16. Large triangular-headed pedicellaria from the actinal surface.

17. Large club-shaped pedicellaria.

18. Same, seen facing the line of division of the jaws.

19. Young club-shaped pedicellaria.

20. Gill-like ambulacral suckers, near the actinostome.

PLATE XXXV\

Genicopatagus affinis, A. Ag. (figs. 1-4), p. 162.

Fig. 1. Actinostome and surrounding plates of specimen measuring 37 mm. in diameter;

greatly enlarged.
„ 2. Apical system and surrounding plates of same, with large tentacles issuing from

double pores.
„ 3. Anal system of same, covered with spines.
„ 4. Ambulacral plates, and adjoining interambulacral plates from the median part of

the test ; magnified.

Cystechinus vesica, A. Ag. (figs. 5-8), p. 150.

„ 5. Abactinal system and adjoining plates.

„ 6. Same, seen from the interior, genital organs removed.

„ 7. Portion of ambulacrum and adjoining interambulacral plates, to show the tuber-

culation of the sides of the test.
„ 8. Interior view of lateral ambulacrum and adjoining interambulacral plates.

Echinocrepis cuneata, A. Ag. (figs 9-13), p. 145.

,, 9. Seen from the abactinal side ; natural size.

,, 10. Same, seen from the actinal side.

,, 11. Same, seen in profile.

„ 12. Smaller specimen, seen facing the anterior extremity.

„ 13. Interior view, showing course of alimentary canal, seen from the actinal side.

308 THE VOYAGE OF H.M.S. CHALLENGER.

PLATE XXXV'^

Periaster Umicola, A. Ag. (figs. 1-4), p, 204.

Fig. 1. Seen from the abactinal side, half test denuded.

„ 2. Same, seen from the actinal side.

„ 3. Same, seen in profile.

,, 4. Same, seen facing the posterior extremity.

Lovenia subcarinata, Gray (figs. 5-7), p. 175.

„ 5. Seen in profile.

,, 6. Same, seen from the abactinal side, partly denuded

,, 7. Same, seen from the actinal side.

Linojmeustes (Paleopneustes) murrayi, A. Ag. (figs. 8-9"), p. 168.

,, 8. Young specimen, seen from the actinal side.
„ 9. Same, seen from the abactinal side.
„ 9 a. Same, seen facing the anal extremity.

Cystechinus clypeatus, A. Ag. (figs. 10, 11), p. 149.

„ 10. Apical system of large specimen.
„ 11. Anal system of same.

Rhinobrissus hemiasteroides, A. Ag. (figs. 12-15), p. 186.

„ 12. Seen from the abactinal side, half test denuded.

,, 13. Same, seen in profile.

,, 14. Same, seen from the actinal side.

,, 15. Same, seen facing the anal extremity.

Pourtalesia ceratopyga, A. Ag. (fig. 17), p. 134.

„ 17. Anterior extremity of test, to show arrangements of plates, from the abactinal
side.

Cionobrissus revinctus, A. Ag. (fig. 18), p. 188.

„ 18. Anterior portion of test, seen from the actinal side (f).
All figures natural size except fig. 18.

REPORT ON THE ECHINOIDEA. 309

PLATE XXXVI.

Schizaster ventricosus, Gray (figs. 1-3), p. 204.

Fig. 1. Seen from the abactinal pole ; natural size.
,, 2. Same, seen from the actinal side.
,, 3. Same, seen in profile.

Mioropsis {Schizaster) clmidicans, A. Ag. (figs. 4-7), p. 205.

,, 4. Seen from the abactinal side ; natural size.

„ 5. Same, seen from the actinal side.

„ 6. Same, seen in profile.

„ 7. Enlarged view of petaloid amljulacra.

Schizaster japonicus, A. Ag. (figs. 8-13), p. 202.

8. Seen from the abactinal side, covered with spines ; natural size.

9. Same, seen from the actinal side.

10. Same, seen in profile.

11. Denuded specimen, seen from the abactinal side.

12. Same, seen in profile.

13. Same, seen from the actinal side.

Schizaster moseleyi, A. Ag. (figs. 14-16), p. 203.

,, 14. Denuded test, seen from the abactinal side.
„ 15. Same, seen from the actinal side.
,, 16. Same, seen in profile.

PLATE XXXVIL

Maretia alta, A. Ag. (figs. 1-4), p. 172.

Fig 1. Seen from above, covered with spines.

„ 2. Same species, test denuded.

„ 3. Same, seen from the actinal side.

,, 4. Same, seen in profile.

Eupatagus valenciennesi, Agass. (figs. 5, 6), p. 173.

,, 5. Seen from the abactinal side.
,, 6. Same, seen from the actinal side.

310

THE VOYAGE OF H.M.S. CHALLENGER.

Lovenia suhcarinata,GYiij (figs. 7-9), p. 175.

Fig. 7. Seen from the abactinal side.
„ 8. Same, seen from the actinal side.
„ 9. Same, seen from the anal extremity.

EchinoJamjxis oviformis. Gray (figs. 10, 11), p. 12.3.

10. Seen from the abactinal surface.

11. Same, seen from the actinal side.
All the figures natural size.

PLATE XXXVIII.

Sections of Spines (figs. 1-31), p. 14.

'ig-

1.

Asthenosoma. gruhii.

Fig

)>

2.

55 55

J)

3.

Pseudoholetia indianci.

»

. 4.

Asthenosoma gritbii.

J5

5.

Phormosoma tenue.

S>

6.

Asthenosoma joelhicidtim.

))

7.

Cceloijle \ iriis ma illardi.

»

8.

55 55

ly

9.

55 55

;!

10.

Salenia hastigera.

55

11.

Goniocidaris Jlorigera.

55

12.

Porocidaris elegans.

55

13.

55 55

55

14.

55 55

55

15.

55 55

55

16.

55 55

17. Aspidodiadema microtuhercu-

latum.

18. „ „

19. Aspidodiadema tonsum.

20. Encope michelini.

21. Mellita testudinata.

22. Clypeaster suhdepressus.

23. Maretia planulata.

24. Linopneustes murrayi.

25. Argopatagus vitreus.

26. Homolampas fulva.

27. Phynchop>ygus p)acific\is.

28. Linopneustes murrayi.
Zy. „ ,,

30. Pourtalesia carinata.

31. 55 55

Fio-s. 1«, 2«, 3", &c., are sectors of the same spine section still more magnified to
show the structure somewhat more in detail.

REPORT ON THE ECHINOIDEA,

311

PLATE XXXIX.

Sections of Spines (figs. 1-38), p. 14.

ig-

1.

5)

2.

9J

3.

S»

4.

3)

5.

}}

6.

>J

7.

?)

8.

>?

9.

3?

11.

5?

12.

!>

13.

JJ

14.

5)

15.

9>

16.

3)

17.

5J

18.

5>

19.

9)

20.

Micropyga tuberculata.

)) if

Phormosoma hoplacantha.

Phormosoma luculentum.
Phormosoma tenue.
Pseudoholetia indiana.
Ecliinolampas oviformis.
Lovenia elongata.
Breynia austrcdasice.
Hemiaster cavernosus.
Hemiaster gibhosus.
Eupatagus valencien nesi.
Argopatagus vitretis.
EncopG michelini.
Genicopatagus affinis.

Fig. 21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.

Aceste hellidifera.
Cionohnssus revinctus.
Aerope vostrata.
Cahjmne relicta.

Cystechinus vesica.
Cystechinus loyvillii.
Urechinus naresianus.

)5 J)

Ech inoci 'ep is cun eata.

)) )>

Palceotropus loveni.
Pourtalesia hispida.
Pouvtalesia laguncida.
Pourtalesia hispida.
Spa tagocystis challengeri.
Periaster limicola.

PLATE XL.

Figures and Details of Spines (figs. 1-68), p. 14.

Fig.

1-25. Goniocidaris tubaria.
26-28. Micropyga tubercidata.
29, 30. Phormosorrm tenue.
31-36. Phormosoma luculentum.
37, 38. Phormosoma hoplacantlm.
39-42. Asthenosoma pellucidum.
43, 44. Prionechinus sagittiger.
45, 46. Lovenia elongata.

Fig. 47-50. Breynia australasice.

51-53. Moiropsis claudicans.

54, 55. Maretia pilamdata.

56-58. Urechinus naresianus.

59, 60. Cystechinus ivyvillii.

61, 62. Pourtalesia laguncida.

63-65. Calymne relicta.

66-68. Aceste bellidefera.

312

THE VOYAGE OF H.M.S. CHALLENGER.

PLATE XLI.

Figures and Details of Spines (figs. 1-53), p. 14.

Fig. 1-6. Periaster limicola.
„ 7, 8. Aerope rostrata.

„ 9, 10. Echinolampas oviformis.

„ 11,12. Eiipatagus valenciennesi.

„ 13-16. Aceste beUidifera.

„ 17-20. Maretia jilanulata.

„ 21, 22. Hemiaster cavernosus.

„ 23-27. Ci/stechimis wijviUii.

„ 28, 29. Palceotropus loveni.

„ 30, 31. Echinocrepis cimeata.

Fig.

32-35. Argopatagiis vitreus.
36, 37. Ci/stechinus vesica.
38, 39, Genicopatcbgus affinis.
40. Spatagocystis challengeri.
41-43. Cionobrissus revinchis.
44-46. Pourtcdesia ceratopyga.
47, 48. Pourtcdesia hispida.
49-52. Pourtcdesia carinata.
53. Pourtalesia laguncula.

PLATE XLIL

Fig.

Pedicellari.e (figs. 1-28).

1. Dorocidaris bracteata, short, long-stemmed ambulacral pedicellaria.

2. Goniocidaris florigera, slender-headed, long-stemmed pedicellaria.

3. ,, ,, globular- headed, short-stemmed abactinal pedicellaria.

4. Aspidodiadema tonsnm, globular-headed, short-stemmed abactinal pedicellaria.

5. „ ,, long-headed, long-stemmed pedicellaria.

6. „ „ magnified part of short interambulacral spines.

7. Phorniosoma tenue, one of the long-headed, long-stemmed pedicellarise.

8. Asthenosoma gruhit, globular-headed, short-stemmed pedicellaria.

9. ,. „ long-headed, long-stemmed pedicellaria.

10. Spatagocystis chcdlengeri, large-headed pedicellaria (PI. XLV. fig. 39).

11. „ ., short-headed, toothed, cup-pronged pedicellaria (PI.
XLV. fig. 43).

12. Spatagocystis challengeri, small-based, long-pronged pedicellaria (PI. XLV.

fig. 12).

13. Cystechimis ivyvillii, large-headed pedicellaria (PI. XLV. fig. 28).

14. „ „ extremity of rod supporting same.

15. Cystechimis clypecdus, small large-headed pedicellaria (PI. XLV. figs. 30, 31).

16. ,, „ end view of same.

REPORT ON THE ECHINOIDEA. 313

Fig. 17. Pourtalesia ceratopyga, large-headed, coarsely-reticulated pediceUaria (PI. XLV.

figs. 57, 58).
„ 18. Pourtalesia ceratopyga, Clypeastroid-like pedicellaria (PI. XLV. fig. 53).
iq .. small large-headed pedicellaria (PI. XLV. fig. 59).

20. „ younger stage of same.

21. „ „ rudimentary spine.

22. ,, „ rudimentary spine.

oq tip of flattened interambulacral spine.

24. Pourtalesia carinata, large-headed, hooked pedicellaria (PI. XLV. figs. 46, 47).

25. ,, „ four-valved pedicellaria.

26. Aceste bellidifera, large, short-stemmed, single-hooked pedicellaria (PI. XLII.

fig. 45).

27. Aceste bellidifera, small, short-headed pedicellaria (PL XLV. fig. 46).

28. „ small-based, long-pronged, pedicellaria.

PLATE XLIII.

Pedicellaria (figs. 1-26).

Fig. 1. Phormosoma hoplacantha, one of the large cup-bearing pedicellaria (PL XLIV.

fig. 29).

2. Asthenosoma gruhii, long-stemmed, small-headed pedicellaria.

3. Echinolamp)as oviformis, ClyiDcastroid-like pedicellaria (PL XLIV. fig. 41).

4. Echinolampas oviformis, dig"erent view of same Clypeastroid-hke pedicellaria

(PL XLIV. fig. 41).

5. Echinolampas oviformis, slender-pronged tridactyle pedicellaria.

6. Linopneustes murrayi, large-headed pedicellaria (PL XLV. fig. 11).
'[7 ^^ ,, large-headed pedicellaria (PL XLV. fig. 13).

g_ ^^ „ short-headed, long-stemmed pedicellaria (PL XLV. fig. 14).

9. Cystechimts vesica, large-headed pediceUaria (PL XLV. fig. 36).
10. ,, ,, long-headed pediceUaria.

11_ ^^ „ long-headed pedicellaria somewhat older.

12. „ „ Cl>TDeastroid-hke pediceUaria (PL XLV. fig. 35).

13. Genicopatagus affinis, large-headed pediceUaria (PL XLV. figs. 20, 20').

14. Echinocrepis cuneata, large-headed pediceUaria (PL XLV. figs. 44, 45).

15. Pourtalesia ceratopyga, large-headed pediceUaria (PL XLV. figs. 57, 58).

' \Q_ „ „ large Clypeastroid-like pedicellaria (PL XLV. fig. 53).

"17 " smaU ClyiJeastroid-Uke pediceUaria (PL XLV. fig. 54).

" " T 40

(ZOOL. CHALL. EXP. PART IX. 1881.)

314 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 18. Pourtalesia laguncula, large Clypeastroid-like pedicellaria, profile.
„ 19. ,, „ full view facing one of the valves of same.

„ 20. Pourtalesia carinata, large-headed pedicellaria.

,, 21, 22, 23. Pourtalesia carinata, Clypeastroid-like pedicellaria ; different views.
„ 24. Calymne relicta, large-based, Clypeastroid-like pedicellaria (PI. XLIV. figs.

47, 48).
„ 25. Aceste hellidifera, large-headed pedicellaria (PI. XLIV. fig. 46).
„ 26. Schizaster jaioonicus, large-headed pedicellaria.

PLATE XLIV.

Pedicellaei.e (figs. 1-48).

Fig. 1. Goniocidaris canaliculata, interior view of a single valve of one of the short-
headed, long-stemmed ambulacral pedicellarise.

„ 2. Goniocidaris canalicidata, -pvo&le of a valve of a short-stemmed globular abac-
tinal pedicellaria.

„ 3. Goniocidaris canaliculata, upper part of rod of a long-stemmed pedicellaria.

„ 4. Goniocidaris Jlorigera, interior view of a prong of the globular-headed, short-
stemmed pedicellarise.

,, 5. Goniocidaris Jlorigera, general view of the head of short-stemmed globular-
headed interambulacral pedicellarise.

„ 6. Porocidaris elegans, interior view of single valve of one of the large-headed,
short-stemmed interambulacral pedicellarise.

,, 7,8. Porocidaris elegans, interior view of valves of smaller pedicellarise.

„ 9. Profile of fig. 8.

,, 10. Porocidaris elegans, interior view of valve of short-stemmed, short-headed,
abactinal pedicellaria.

„ 11. Porocidaris elegans, interior view of large-headed, short-stemmed interambu-
lacral pediceUariae.

,, 12. Base of rod supporting valve of fig. 6.

„ 13. Base of rod supporting valve of fig. 11.

„ 14. Extremity of rod supporting valve of fig. 11.

„ 15. Aspidodiadenia tonsuni, valve of long-headed, long-stemmed pedicellaria, seen
from the interior.

,, 16, Aspidodiadema ww'croitt&ercMZaitMn, magnified portion of secondary spines.

,, 17, „ „ head of rod supporting long-headed, long-

stemmed pedicellaria.

REPORT ON THE ECHINOIDEA. 315

¥i(y. IS. Aspidodiadema microtttherculatum, valve seen from the interior of globular-
lieaded, short-stemmed abactinal pcdicellarias.

19. Phormosoma tome, valve of long-headed pedicellaria, seen from the interior.

20. „ ,, valve of smaller pedicellaria of same kind as fig. 19, seen
from exterior.

„ 21. Phormosoma tenue, small, bottle-shaped, didactyle pedicellaria.
^^22. ,, ,, single valve of same as fig. 21, seen from interior.

23. „ „ valve of still smaller pedicellaria than fig. 20, and of same
kind, seen from interior.

24. Phormosoma tenue, upper extremity of rod supporting the long-headed pedi-

cellarise.

25. Phormosoma luculentum, interior view of single valve of globular-headed short-

stemmed pedicellaria.
,, 26. Exterior view of the valve of fig. 25.

27. Phormosoma luculentum, profile of single valve of small short-headed, short-

stemmed pedicellaria.

28. Phormosoma hoplacantha, upper extremity of rod supporting long-headed

pedicellarise.

29. Phormosoma hoplacantha, single valve seen from exterior of one of the cupped

pedicellariae.
29'. Phormosoma hop>lacantha, interior view of same pedicellaria showing the trough
extending to the base of the pedicellarise from the edges of the lip of the cup
of the extremity of the valve.

30. Phormosomxi hoplacantha, interior view of base of one of the same pedicellarise.
3X. ,, ,, upper extremity of rod supporting the above pedicel-
laria of fig. 29.

„ 32. Asthenosoma gruhii, upper extremity of rod of large-headed pedicellaria.

33. „ „ magnified view of one of the sheathed spines denuded.

34. ,, „ interior view of valve of short-headed, globular abactinal
pedicellaria.

,, 35. Asthenosoma gruhii, upper end of rod supporting long-headed, long-stemmed
pedicellarise.

36. Asthenosoma gruhii, interior view of valve of large-headed pedicellaria.

37. Micropyga tuhercxdata, profile view of large-headed pedicellaria.

38. Pseudoholetia Indiana, interior view of large short-stemmed single-hooked

pedicellaria.
„ 39. Pseudoholetia Indiana, interior view of large-headed, short-stemmed pedicellaria.

40. ,, „ extremity of rod supporting large-headed pedicellaria.

41. Echinolamixis oviformis, single valve of Clypeastroid-like pedicellaria.

316 THE VOYAGfE OF H.M.S. CHALLENGEE.

Fig. 42. Echinolampas oviformis, extremity of pointed spine, interambulacral spine
(enlarged).

,, 43. Echinolampas oviformis, upper extremity of rod supporting the pedicellarise of
fig. 41.

,, 44. EcJiinolarapaft oviformis, enlarged view of upper extremity of fan-shaped inter-
ambulacral spine.

„ 45. Aceste bellidifera, interior view of large, short-stemmed, single-hooked pedicellaria.

,, 46. ,, „ interior view of small short-headed pedicellaria.

„ 47. Calymne relicta, single valve of Clypeastroid-like pedicellaria.

„ 48. „ „ upper extremity of spiny rod supporting the same.

PLATE XLV.

Pedicellaria (figs. 1-59).

Fig. 1. Caslojileurus maillardi, interior view of single valve of large-headed, long-
stemmed pedicellaria.

„ 2. Profile of same as fig. 1 .

„ 3. Coelo])leurus maillardi, interior view of globular, short-headed, short-stemmed
interambulacral pedicellaria.

„ 4. Profile of same as fig. 3.

„ 5, 6. Cceloplexirus maillardi, upper extremities of rods supporting the pedicellarise.

„ 7. Schizaster japonicns, inteiior view of large-headed, interambulacral abactinal
pedicellaria.

„ 8. Scliizaster jaj^onictis, exterior view of same as fig. 7.

„ 9. „ ,, profile of a similar pedicellaria, somewhat smaller.

, 10. ,, „ ujjper extremity of rod supporting these pedicellarife.

„ 11. Linopneustes murrayi, interior view of large-headed, short-stemmed pedi-
cellaria.

„ 12. Linopneustes murrayi, profile view of another pedicellaria of the same kind.

„ 13. „ ,, profile of a more elongate pedicellaria.

„ 13'. Interior view of another still larger pedicellaria of the same kind.

,, 14. Single valve, profile view of the short-headed, long-stemmed pedicellarise.

,. 15. Linopneustes murrayi, general view of a short-headed pedicellaria.

„ 16. Interior view of valve of same as fig. 15.

„ 17. Linopneustes murrayi, interior view of base of large-headed pedicellaria (like
fig. 11), but more serrate.

,, 18, 19. Linopneustes murrayi, upper extremity of rod supporting large-headed
pedicellaria, with a magnified portion of same.

E,EPOET ON THE ECHINOIDEA. 317

Fig. 20. Genicopatagus affinis, profile of large-headed, S^iatangoid-like pedicellaria.

„ 20'. „ ,, different view of another pedicellaria of same kind.

„ 21. „ ,, interior view of base of same pedicellaria.

„ 22. ,, „ magnified view of upper extremity of rod supporting

pedicellarise.

,, 23. Genicopatagus affinis, general view of upper extremity of rod.

,, 24. „ „ portion of shank of rod.

,, 25. Cystechinus ivt/viUii, magnified interambulacral spine.

„ 26. ,, ,, rod supporting the pedicellariae of fig. 27.

,, 27. „ ,, Clypeastroid-like pedicellaria.

5, 28. „ „ large-headed (Si^atangoid-like) pedicellaria.

„ 29. Cystechinus clypeatus, one of the club-shaped interambulacral spines magnified.

,, 30. „ „ extremity of a large-headed, small pedicellaria, seen from

the exterior.

,, 31. Tip of same as fig. 30; magnified.

„ 32. Cystechinus vesica, magnified view of interambulacral spine.

„ 33. ,, ,, tip of rod carrying the Clypeastroid-like pedicellaria of

fig. 35.

„ 34. Cystechinus vesica, extremity of interambulacral primary spine ; magnified.

,, 35. ,, „ Clypeastroid-like j)edicellaria.

„ 36. ,, ,, interior view of large-headed pedicellaria.

„ 37, 38. Spatagocystis challengeri, upper extremity of rods carrpng large-headed
pedicellarise.

„ 39. Spatagocystis challengeri, profile of large-headed pedicellaria.

„ 40. ,, „ interior view of base of same.

„ 41. ,, „ interior view of large-based, slender-pronged pedi-

cellaria.

,, 42. Spatagocystis challengeri, interior view of base of small-based, long-pronged
pedicellaria.

,, 43. Spatagocystis challengeri, exterior view of short-headed, toothed, cup-pronged
short-stemmed pedicellaria.

„ 44. Echinocrepis cuneata, profile of large-headed pedicellaria.

,, 45. ,, ,, extremity of rod carrying same.

,, 46. Pourtalesia carinata, profile of large-headed, coarsely-reticulated, hooked pedi-
cellaria.

„ 47. Interior view of a pedicellaria of same kind as fig. 46.

„ 48. Pourtalesia carinata, large-headed pedicellaria, seen partly in profile.

,,49. ,, ,, large-based, slender-pronged valve, seen from interior.

,, 50. ,, „ another large-headed, closely-reticulated pedicellaria valve.

318 THE VOYAGE OF H.M.S. CHALLENGEE.

Fig. 51. Pourtalesia carinata, rod carrying the pedicellarige of figs. 46, 47.
„ 52. „ ,, magnified interambulacral abactinal spine.

,, 53. Pourtalesia ceraiopyga, valve of large Clypeastroid-like pedicellaria.
„ 54. Valve of small pedicellaria of same kind as fig. 53.
„ 55. Pourtalesia ceratopyga, upper extremity of rod supporting the above.
„ 56. ,, „ broad based, slender-pronged, and hooked pedicellaria.

„ 57. ,, ,, profile of large-headed coarsely-reticulated, hooked

pedicellaria.
,, 58. Interior view of another pedicellaria of same kind as fig. 57.
„ 59. Pourtalesia. ceratojoijga, small, large-headed pedicellaria, with smooth valvular

edge.

INDEX OF GENERA AND SPECIES.

Aceste, 195.

hellidifera (Pis. xxii., xxxm.^ xxxix., xl.,
xlL, xlii., xliii., xliv.), 195.
Aerope, 190.

rostrata (Pis. xxxiii., xxxiii.", xxxix., xli.),
192.
Amhlypneustes, 114.

formosus, 114.
Arhacin, 56.

dufresnii, 58.
nigra, 58.
pustulosa, 58.
Argopatac/us, 160.

vitreus (Pis. xxxii., xxxviii., xxxix.,
xli.), 160.

Aspidodiadema, 64.

microtubercidatum (Pis. viii.,

xxxviii., xliv.), 65.
tonsum (Pis. viii., xxxviii., xlii.,

xliv.), 66.

Asthenosoma, 82.

coriacezan (PI. xvii."), 88.

(/ra«7e (PL xvii.°), 89.

(/n<5e2 (Pis. XV., xvi., xvii., xxxviii.,

xlii., xliii., xliv.), 82.
pellucidum (Pis. xviii., xviii,% xLx.,

xxxviii., xl.), 85.
tessellatum (Pis. xii.', xix.", xix."), 88.
Astridypeus, 121.

manni, 121.
Astropyga, 70.

pulvinata, 70.

Breynia, 177.

mistrcdasice (Pis. xxi., xxxix., xl.), 177.

Biissopsis, 189.

luzoniea, 189.

lyrifera, 189.
Brissus, 197.

damesi (PI. xxx.""), 197.

Calymne, 154.

reZ/cta (Pis. xxxiv., xxxix., xl., xliii,
xliv.), 155.

Catopygus, 123.

9-<3ce?w (PL XX.), 123.
Cidaris, 33.

trihuloides (PL L), 36.
Ciondbrissus, 187.

revinctus (Pis. xxiii., xxxv."", xxxix.,
xxli.), 188.
Clypeaster, 119.

humilis, 119.
scutiformis, 119.
subdepressus (PL xxxviiL), 119.
Coslopleurus, 60.

maillardi (Pis. v., vi., xxxviii., xlv.),
60.
Cottaldia, 112,

forheskma (PL vL'), 112.
CystecMnm, 148.

clypeatus (Pis. xxxv.", xlii., xlv.), 149.
tJCMca (Pis. xxxv., xxxv.°, xxxix, xli.,

xliiL, xlv.), 150.
imjvillii (Pis. xxix., xxix.% xxix.",
xxxix., xl., xli., xlii., xlv.), 152.

Diadema, 64.

setosum, 64.
Dorocidaris, 37.

bradeata (Pis. i., xlii.), 37.
papillata, 38.

Ecldnanthus, 120.

testudinarius, 120.
Echinocardium, 173.

australe 174.
flaoescens, 175.
EcMnocrepis, 143.

CM«ea<a (Pis. xxvii., xxxv.^ xxxix ,
xlL, xliii., xlv.), 145.
Ecliinoeyatnus, 118.

pitsillus, 118.
Echinodiscm, 121.

Icevis, 121.
Ecliinolampas, 122.

oviformis (Pis. xxxvii., xxxix., xli.,
xHii., xliv.), 123.

320

THE VOYAGE OF H.M.S. CHALLENGER.

Ehinometra, 105.

lucunter, 105.
suhangidaris, 106.
Eclunoilirix, 67.

calamaris, 67.
tiircariim, 67.

EOHINOTHUEID.E, 71.

Echinus, 114.

aciUiis, 114.

angulosiis, 115.

elegcuis, 115.

7ior>7'(^?« (Pis. vi."), 115.

viagellanicus, 116.

margaritaceus, 117.

norvegicm, 117.
Encope, 122.

emarginata, 122.
Eupatagus, 173.

valendennesii (Pis. xxxvii., xxxix. , xl.),
173.
Evechimis, 118.

chlorotieus, 118.

Fihularia, 119.

mistralis, 119.
volva, 119.

Genieopatagiis, 161.

affi.7iis (Pis. xxxi., xxxv.", xxxix.,
xli, xliii., xlv.), 162.
Goniocidaris, 43.

caHaliculata (Pis. ii., xliv.), 43.
florigcra (Pis. i., xxxviii., xlii., xliv.),
46.
ftt&arja (PI. xl.), 49.

Hemiaster, 177.

ccweniosMS (Pis. xx.% xxxix., xli.), 177.
gihhosus (Pis. xx., xxxix.), 184.
zoKa<?«s (PI. XX.), 186.
Heterocentrotus, 105.

mammiUatus, 105.
trigonarius, 105.
Hippono'e, 118.

variegata, 118.

HOLASTERID^, 159.

Holopneustes, 114.

]}m-puresceiis, 114.
Homolampas, 163.

fnigilis, 166.

/;t?t'a (Pis. xxiv., xxxviii.), 164.

Laganum, 120.

depressum, 120.
putnariii, 120.
Linopneustes, 167.

murruyi (Pis. xxv., xxxv.'', xxxviii.,
xiiii., xlv.), 168.
Lovenia, 175.

elonguta (Pis. xxxix., xl.), 175.
suhcarinata (PI. xxxv.*"), 17-5.

Marctia, 172.

aZfa (PI. xxxvii.), 172.
planulata (Pis. xxxviii., xl., xli.), 17.3.
i/eWiYa, 121.

sexforis, 121.
Mespilia, 114.

globulus, 114.
Metalia, 199.

maadosa, 199.
pedoralis, 199.
Bl/croci/phus, 111.

zigzag, 111.
Micropyga, 67.

fubeirulata (Pis. vii., xxxix., xl.,
xliv.), 68.
Moiropsis, 205.

claiidicans (Pis. xxxvi., xl.), 205.

Pidmotropus, 157.

loveni (Pis. xxi., xxxix., xli.), 158.
PeriasUr, 204.

limieola (Pis. xxxv.'', xxxix., xl), 204.
Peronella, 120.

decagonalis, 120.
peronii, 121.
Pliormosoma, 91.

asferms (PI. xii."), 104.
hursarium (PI. x."'), 99.
hoplacantha (Pis. xi., xii., xii.", xxxix.,

xl., xliii., xliv.), 101.
luculentum (Pis. ix., x., x.", xxxix., xl.,

xliv.), 97.
rigidum (PL xii."), 104.
tow^e (Pis. xiii., xiv., xvii.", xviii.,
xvLii.", xvui.*", xviii.*^, xix., xix.",
xxxviii., xxxix., xl., xUi., xliv.),
91.
Pliormosoma uranus (PL xviii."), 103.
Phijllacanthus, 39.

annulifera, 39.
haculosa, 39.
gigantea, 40.

EEPORT ON THE ECHINOIDEA.

321

Phyllacanthus verticillata, 40.
Pleurechinus, 108.

hothnjoides (PI. x."), 108.
Podocidaris, 59.

•prionigera (PI. xxxiv.), 59.

sculptu, 60.
Porocidaris, 40.

elegans (Pis. iii., xxviii., xliv.), 40.

PoDRTALESLa;, 124.

Pourtalesia, 132.

carinata (Pis. xxviii.% xxxviii., xli.,

xlii, xliii., xlv.), 13.3.
ceratojnjga (Pis. xxviii., xxxv.", xli.,

xlii., xUii., xlv.), 134.
hispida (Pis. xxii., xxxix., xli.), 136.
lagwicida (Pis. xxii.', xxxi., xxxix.,

xl., xli., xliii.), 137.
pJiiale (Pis. xxii., xxii.'), 138.
rosea (PI. xxii."), 139.
Pnonechimis, 109.

sagittiger (Pis. vi.», xl.), 109.
Pseudoboletia, 107.

Indiana (Pis. xxxviiL, xxxix., xliv.),
107.

Bhinohrissus, 186.

hemiasteroides (PI. xxxv.""), 186.

Scdenia, 50.

hasttgera (Pis. iv., xxxviii.), 54.
varispina (PL iv.), 55.
Salmacis, 113.

hicolor, 113.
dussumieri, 113.
glohator, 113.
rarispina, 113,

Salmacis sidcata, 114.
Schizaster, 199.

fragilis, 201.

japonicus (Pis. xxxvi., xliii., xlv.)

202.
moseleiji (PI. xxxvi.), 203.
ventricosus (PI. xxxvL), 204.
Spatagorystis, 140.

challengeri (Pis. xxvi., xxvi.", xxxix.,
xli., xlii., xlv.), 141.
Spatangtis, 171.

purpureus, 171.
raschi, 171.
Splicer echinm, 106.

atistrcdice, 106.
gramdaris, 106.
Strongyloceftitrotus, 106.

drbhacldensis, 106.
eurt/ihrogrammus, 106.
giTjhosus, 106.

Temnophurus, 107.

hardwickii, 107.
reynaudi, 107.
toreunicdicus, 108.
Tuxopneustes, 117.

pileohis, 117.
variegatus, 118.
Trigonocidaris, 111.

inonolini (PI. vi."), 111.

Urechimis, 146.

nccresianus (Pis. xxix., xxx., xxx.%
xxxix., xl.), 146.

(ZOOL. CHALI.. EXP. PART IX. 1881.)

141

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THE

VOYAGE OF H.M.S. CHALLENGEE,

ZOOLOGY.

REPORT on the Pycnogonida, dredged by H.M.S. Challenger during the
years 1873-76. By Dr P. P. C. Hoek, Assistant at the Zootomical
Laboratory of Leiden University.

The beautiful and rich collection of Pycnogonida formed during the exjiedition of
the Challenger has been placed in my hands by Professor Sir WyvUle Thomson, F.R.S.,
for description in the official report of the voyage.'

Our knowledge with regard to the Pycnogonids in general, their systematic arrange-
ment, their geographical distribution, &c., is still very insufficient ; and with respect to
those of the greater depths of the ocean hardly anything is known.

The first attempt towards a monograph of the Pycnogonida is that of George
Johnston.^ His paper was published in 1837, and treats of the British species known up
to that time. Though no special paper on Pycnogonids seems to have been published
previous to Johnston's, yet there are several works of an older date, in which descrip-
tions of species and genera belonging to this group occur, as well as discussions as to
their place in the Zoological System. But as the descriptions are for the greater
part very incomplete and the species therefore not to be recognised, these works are
interesting only in so far as they show how much uncertainty has always been felt as to
the place of the Pycnogonids among the Arthropoda.

Linnseus (1767)' brings the forms known to him under the genus Phalangium,
in which also numerous land-spiders are placed, and which he ranges between
Hydrachna and Aranea under his Insecta aj^tera.

' I wish to tender my sincere thanks to Professor Sir Wyville Thomson, F.R.S., &c., who liberally trusted to me —
though a stranger— the drawing up of this report ; at the same time to Mr Jolm Murray who has kindly given me
much valuable assistance.

2 George Johnston.— An Attempt to ascertain the British Pycnogonida, in the Magazine of Zoology and Botany,
conducted by AV. Jardine, P. J. Selby, and G. Johnston, vol. i., 1837.

' Carolus Linnseus, Systema Naturae, editio .xii. rev., 1766.
a r (ZOOL. CHALL. EXP. PART X. — 1881) K 1

^

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WOODS

HOLE,

MASS,

2 THE VOYAGE OF H.M.S. CHALLENGEE.

Otho Fabricius (1780)^ assigns to tliem tlie name Pycnogonum proposed by
Briinnicli, and places the Cyainus ccti with them in the same genus. He believes them
to be most closely allied to Crustaceans.

J. C. Fabricius (1794)^ places the two genera Pycnogomim and Nymjihon along with
Pedicidus, Acarus, &c., in the eleventh class (the Antliata) of his entomological system.

Lamarck (1801) ^ gives the same genera {Pycnogonum and Nymjjhon) a place in the
class of the Arachnida, order of the Palpistes, together with Bdella, Acarus, and Hydrachna.

Savigny (1816) * proposes to place the Pycnogonida among the Crustacea, an opinion
afterwards embraced by Milne-Edwards (1834)' and Johnston (1837). According to
Johnston, Savigny arrived at this conclusion by a very ingenious analysis of theii- organs.
He pointed out that the proboscis of the Pycnogonum is a head, whereas the mandibles,
palpi, and ovigerous organs are merely modifications of the legs, so that the Pycnogonida,
like the Crustaceans, really have seven pair of legs, &c.

Johnston " himself, taking the assertions of Savigny as decisive, disagrees with those
naturalists who object to the Pycuogonids being placed among the Crustaceans on
account of the great simplicity of their anatomy. With Milne-Edwards he considers the
Pycnogonids, although imperfect and even degraded, as formed on the same general plan
as that of all the numerous other animals rightly placed in the class Crustacea.

There can l^e no doubt that Johnston's publication is one of the most important
in the history of the knowledge of the group. Johnston gives a very clear descrip-
tion of the body of a Pycnogonid, fully discusses the systematic position of the order,
proposes good characteristic marks for the genera, and enters into detailed descrip-
tions of the species. The numlier of genera in his paper amounts to five {Nymphon,
Pallene, Orithyia, Phoxichilus, Pycnogonum), each with one species, with the exception
of the genus NymiDhon, to which two species are assigned.

Of the authors who come after Johnston, Milne-Edwards is the first to be mentioned.
In the third volume of his Histoire naturelle des crustaces (1840), he gives a very short
description of the body of a Pycnogonid, and enumerates, but without paying special
attention to the group, the species and genera known to him. Following Johnston as
nearly as possible, he has the same five genera ' and almost the same species. His descrip-
tions are very insufficient; his work derives importance only from the circumstance that
he places— as I have abeady mentioned above— the Pycnogonids among the Crustaceans
as a distinct order, viz., that of the Araneiformes.

1 Othonis Fabricii Fauna Groenlandica, Hafnise et Lipsiw, 1780.

= Joh. Christ. Fabricii Entomologia Systematica emendata et ancta, torn, iv,, 1794.

* J. B. Lamarck.— Systems des animaux sans vertfebres, i Paris, an. ix., 1801.

* J. C. Savigny.— Memoires snr les animaux sans vertfelires, premiere partie, 1816.
5 H. Milne-E(iwards.— Histoire naturelle des Crustaces, torn, i.-iii., 1834-40.

« In this introduction only the most important authors are mentioned ; a much fuller list is given liy Johnston in
his An Attempt, &c., and by Milne-Edwards, loc. cit.

' The name Orithyia of Johnston "etant dcjJi employ^ poiu' un autre genre de Cnistac^," is changed by Milne-Edwards
into Phoxichilidium (I.e., p. 535).

REPORT ON THE PYCNOGONIDA. S

The species of the English coast found (1842-44) a new monographer in Goodsir,*
who in three consecutive papers enumerates a large number of species new to the fauna
of the British Isles and to science in general. Two new genera {Pephrcdo and Pasithoe)
are proposed by him, but owing to the want of detail jVIi- Goodsii-'s papers are of little
value, for it is absolutely impossible to recognise either his new genera or his new species
from such descriptions as he gives.

Of as little value is the list given by Hodge (1864),- in which all Goodsii-'s species
are found, in addition to some new Ammotheas and species of his new genus Achelia.
Since Hodge's list — though occasionally in English periodicals short descriptions of new
species have been published — no special paper on the Pycnogonids of the English coast
has appeared.

Those of the Norwegian coast found a very able describer in Kroyer (1845),^ who
gives very clear diagnoses of the genera and species. As a new genus he proposes
Zetes, and the total number of species described by him is twelve. These descrip-
tions were published without illustrations ; but illustrations to the text may be found
in Quoy and Gaimard's Voyages en Scandinavie, Laponie, &c., Zoologie, Crustaces,
pi. xxxix. (1840).

For the Pycnogonids of Northern Europe and the coasts of the Arctic Ocean, liesides
Kroyer, the following authors must be mentioned: — Otho Fabricius* for the coast of
Greenland, as mentioned above. Sabine' (1824) describes two Nymphons {N. cjrossqKS and
N. liirmtum) and a species of Phoxichilus {P. proboscideus — a true Colossendeis, Jar-
zynsky), found on the shores of the North Georgian Islands. Bell (1855)," in Belcher's
Last of the Arctic Voyages, gives descriptions and drawings of two new species of Nym-
phon {N. hirtipes and N. rohustum) common in higher northern latitudes. Jarzynsky (1870)'
enumerates the species of Russian Lapland and the White Sea. A new genus (Colos-
sendeis) is proposed by him. Buchholz (1874),' in the narrative of the second German
North Polar Expedition, enumerates three species of Nynvplion, but none of these are new.

1 Han-y D. S. Goodsir.— Edinburgh New Philosophical Journal, vol. xxxii., 1842 ; ihul, vol. x.xxiii., 1842 ; On the
Specific and Generic Characters of the Araneiform Crustacea, Annals and Mag. of Nat. Hist., vol. xiv., 1844.

2 George Hodge.— List of the British Pycnogonoidea, with descriptions of .several new species, Ann. and Mag. of
Nat. Hist., vol. xiii., 3d series, 1864.

2 Henrik Kroyer.— Bidrag til Kundskali oni Pyknogoniderne eller Sospindlerne, Natur-historisk Tidskrift, Ny
Raekke, i., 1845.

^ Loc. cit.

5 A Supplement to the Appendix of Captain Parry's Voyage for the Discovery of a North-West Passage in the
years 1819-20, containing the Zoological and Botanical Notices, London, 1824 ; Marine Invertebrate Animals, by
Captain Edw.ard Sabine.

''• Thomas Bell.— Account of the Crustacea of the Last of the Arctic Voyages in Seartdi of 8ir .John Franklin,
under the command of Captain Sir E. Belcher, C.B., &c., in two volumes, vol. ii., 1855.

' Th. Jarzynsky. — Proinissus catalogus Pycnogonidarum invent.irum in mari glaciali ad i>ras Lapponia; rossicae et
in Mari albo, anno 1869 et 1870, Annales de la Soc. des Natur. de St Petersli., 1870.

» R. Buchholz.— Crustaceen der Zweiten Deutschen Nordpolarfahrt, Anhang : Pycnogonida Die Zweit Deutsche
Nordpolarfahrt, ii. 396, 1874.

4 THE VOYAGE OF H.M.S. CHALLENGEE.

Heller (1875)^ proposes two new species of the same genus gathered during the Austrian
North Polar Expedition ; both are identical -^dth species described before under other
names.

In 1877 and again in 1879 G. 0. Sars" published lists of the Pycnogonids gathered
durino- dredo-ing cruises in the northern part of the North Atlantic, on the coast
of Norway, &c. There are in all four new species of Nymphon {N. megcdops,
N. macronyx, N. serratmn, and N. paUenoides) , a new genus, Ascorhynchus, with the
species Ascorhynchus ahyssi, a new species of Colossendeis {C. angusta), and a new
Pallene, P. malleolata.

Miers (1877)'' treats of the Pycnogonids collected during the last EngUsh Arctic
Expedition. He gives two species, neither of which is new, and describes a variety of
Nymjihon hirtum.

In regard to the coast of Germany and the Netherlands not a single species has been
recorded which is not found on the English coast. Occasionally enumerations of species
have been published by Frey and Leuckart,* and Bohm.^ In a paper I published myself
(1877)" I described the four genera, species of which are found on the Dutch coast.

The Pycnogonids of the French coast have been studied by Quatrefages (1844),'
Claparede (1863),' Hesse (1867-74),' and Grube (1868-72).'" Their studies resulted in
the proposal of a new species of Ammothea {A. pycnogonoides, Quatr.), of a new
Phoxichilidium (?) (P. chelifenim, Claparede), a new species of Phoxichilus {P. lavis,
Grube, and two new genera (?) Oiceobathes, Hesse, and (?) Oomenis, Hesse, both very
insufficiently described. The Pycnogonids found on the coasts of France, the British
Isles, Germany, &c., are not yet sufficiently well known to allow of thek geographical
distribution being discussed.

About the species of the Mediterranean very little is known. Philippi (1843)" and

1 Camil Heller.— Die Crastaceen, Pycnogoniden, mid Tunicaten der K. K. Oester. Ungar. Nordpol. Expedition,
Denkschrifteu der Mathematisch-Naturwiss. Classe der K. Akad. der Wissensch., Bd. xxxv., Wieu, 1875.

2 G. 0. Sars.— Prodromus descriptionis Crustaceonun et Pycnogonidarum, quae in expeditioue Norvegica, anno 1876,
oljservavit, Arch. f. JIath. og Natiuvid., ii., 1877 ; Crustacea et Pycnogonida nova, quae in itinere 2*0 et S''" expeditionis
Norvegicaj, anno 1877 et 1878, collect;! (Prodromus descriptionis), ibid., iv., 1879.

' Edward J. Miers.— Report on the Crustacea collected by the Natiiralists of the Arctic Expedition in 1875-76,
Amials and IMag. of Nat. Hist., fom-th series, vol. xx., 1877.

' Frey and Leuckart. — Beitrage sur Kenntniss wirhelloser Thiere, 1847.

^ R. Bohni.— Ueher die Pycnogoniden des Konigl. Zool. Museums zu Berlin, Mouatsber. der Konigl., Akad. der Wiss.
1879.

" P. P. C. Hoek. — Ueber Pycnogoniden, Is'iederl. Archiv. f. Zoologie, iii., 1877.

' A. de Quati-el'ages.- Memoire sur I'organisation des Pycnogonides, Ann. d. Sc. Natur., S""" Serie, Zoologie, torn.
iv., 1845.

' A. Rene Edouard Claparede. — Beobachtungen tiber Anatomie und Entwickelmigsgeschichte wirbelloser Thiere
an der Kiiste von Normandie angestellt, 1863.

" Hesse. — Annales des Sciences naturelles, Si'iJ"-' Serie, vii., 1867 ; ibid. 5'^"^ Serie, xx., 1874.

"> Edward Grube. — Mittheilungeu iiber St Malo und Roscoff und die dortige Meeres besonders die Anneliden-fauna,
1869 ; MittheUungen iiber St Vaast la Hougue, und seine Meeres, besonders seine Anneliden-fauna, Verhandl. der
Schlesischen Gesellsch. f. vaterl. Cultur., 1869.

'1 A. Phillipi. — Ueber die Neapolitanischen Pycnogoniden, Arch. f. Naturgesch, ix., 1843.

REPORT ON THE PYCNOGONIDA.

Costa (1838-61)^ puljlished short notes on the Pycnogonids found there. Philippi proposed
a new genus {Endeis), which is perhaps identical with Pasithoe, Goodsir ; and a second genus
(Parihoea), with the species Parihoea sinnipalpis. Costa introduces (1838) the genus
Phanodemus, in all probability identical with Pepkredo, Goodsir ; in his Microdoride medi-
terranea (1861) he proposes three new genera : Rhynchothorax, Plati/chelns, and Ahynous.
From the Gulf of Naples Costa knows in aU seven species, whereas the total number of
species of the Mediterranean found in Philippi's paper is only four. A monograph on
the Pycnogonids of the Mediterranean, and especially of the Gulf of Naples, ^ill very pro-
bably soon appear ; it will form the second part of the Studi e Ricerche di Cavanna (1877),'^
and will also be published by Dohrn, as announced in his Neue Untersuchungen (1878).'

Of all Pycnogonida, those found on the west coast of North America are best known.
Careful attention was paid to them by Stimpson (1852),* Verrill, Smith (1874),-' but
especially by Wilson (1878-80)," who in his Pycnogonida of New England, enumerates
fourteen species belonging to nine genera, two of which {Pseudopcdlene and Anoplo-
dactylus) are new to science. Though I do not believe that these new genera after a
careful examination wall hold good, and though I think it a pity that Wilson in his
researches has not taken advantage of recent investigations (especially those of Cavanna),
yet there can be no doubt, I believe, that his paper is one of the best descriptive publi-
cations after those of Johnston and Kroyer.

For the other countries of our glolx% a very brief enumeration may suffice. As far
as I have been able to ascertain, l)y far the greater numl^er of the species described are
littoral ; from the open ocean very few species are recorded. Two species described by
White (1847),' inhabiting the South Sea, are exceptions. White describes them as species
of Nymphon, whereas I believe that they ought to be considered as PhoxichiUdmms.
From the open ocean are also those species (one of Nymphon, another of Phoxichilidium)
mentioned by Grube (1869)^ as occurring in the Chma Sea. Grube's descriptions as
well as those of White are extremely incomplete.

Wood-Mason (1873)' described a species of a genus which he believed to be new,

1 0. G. Costa.-Fauna del Regno di Napoli, Crostacei et Aracnedi, Napoli, 1838 ; Microdoride mediterranea, tomo

prirao, Napoli, 1861. . ,. „ ,. . •

2 G. Cavanna.-Studi e Ricerche sm Picnogonidi, parte prima (Publicazioui del R. Istituto di Studi saperiori
pratici et di perfezionamento in Firenze, Sezione di Scienze fisiche e naturali), Fireuze, 1877.

3 A Dolirn.-Neue Untersuchungen iiber Pycnogoniden, Mittheil. a. d. Zoologischen Station'zu Neapel, i., 1879.

* William Stimpson.-Synopsi8 of the Marine Invertebrata of Grand Manan, Smithsonian Contributions to Know-
ledge, January 1853.

5 Smith in Report on the Invertebrata of Vineyard Sound. In Part I. of the Report on the Condition of the Sea-
Fisheries of the South Coast of New England, 1873. , „ c. • i » *

8 E B Wilson.-Descriptions of Two New Genera of Pycnogonida, American Journal of Science and Arts,
vol XV , 1878 ; Synopsis of the Pycnogonida of New England, Transactions of the Connecticut Academy, vol. v., 1880.

7 AdamWhite.-Descriptionsof Newor Little-Knowai Crustacea in the CoUectiou at the British Museum, Pro-
ceedings of the Zoological Society of London, part 15, 1847.

8 E Grube in Jahresbericht der Schlesischen Ges. fiir vaterliindische Ciiltur, Breslau, 1869.

» James AVood-Mason.-On Rlwpalorhynchus kroyeri, a new Genus and Species of Pycnogonida, with plate xiii.,
Journal of the Asiatic Society of Bengal, part 2, 1873.

b THE VOYAGE OF H.M.S. CHALLENGER.

and called Rliopalorliynchus. There can be no doubt that this is the same as the genus
formerly (1870) described by Jarzynsky^ as Colossendeis. AVood-Mason's species is an
inhabitant of Port Blair, Andaman Islands.

Miers (1875 and 1879)^ mentions two species of Ni/mphon, and one of a new genus,
which he calls Tanystylum, and which is nearly allied to Achelia. These species were
collected at Kerguelen Island during the ^dsit of the English and American Transit of
Venus expeditions to that Island. Btilim (1879)'' has made a very careful study of the
Pycnogonids of the Royal Zoological Museum at Berlin. He describes two species of
Nymphoii and one of Achelia, as collected at Kerguelen; one species of Nymplion col-
lected south of the Cape of Good Hope, one Pallene (?) taken in the Straits of Magellan,
another Pallene from Mozambique, a PhoxicMlidium and a Phoxichilus collected in the
neighbourhood of Singapore ; finally, besides some species from Northern Europe, three
species found near Enosima (Japan); one species of a new genus, which Bohm calls
Lecithorhynchus, one Ascorhynchus (GnamjJtorhynchus, Bohm), and one species of
Pallene. Slater (1879)* published a short j^aper on a new genus of Pycnogonids {Para-
zetes) found in Japan, and descrilDcd in the same paper a variety of Pycnogonum litorale
from the same country.

In the Boston Journal of Natural History, Eights (1836"?) mentions the genus Decalo-
poda, but I have not been able to ascertain whether this is a good genus, nor where it
has been found.® A species of Pasithoe described by Dr Gould'' is, according to Wilson
{loc.cit. p. 2), " indeterminable." To Mr Wilson's paper I am also indebted for the men-
tion of a species of Pycnogonid found on the coast of Chili : it seems to be a species of
Pyc7iogonum.''

In this enumeration the reader will not find a complete list of the descriptive litera-
ture of Pycnogonida, but all the more important publications, together with the greater
number of the minor papers on our group are mentioned. With a few exceptions the
zoological publications about Pycnogonids are very superficial, and this I believe is owing
partly to the circumstance that many authors who have had no opportunity of comparing
large collections of difierent forms have published descriptions of species and even of
genera from the examination of such species only. To describe new species, however, ought

' Th. Jarzyusky, loc. cit.

- E. J. Miers. — Descriptions of new species of Crustacea collected at Kerguelen's Island, by tlie Rev. A. E. Eaton.
Annals and Magazine of Natural History, fourth series, vol. xvi., 1875 ; Crustacea of Kerguelen Island, Philosophical
Transactions, London, vol. clxviii.; extra volume, pp. 200-214, 1879, pi. .\i.

^ R. Bohm, loc. cit.; the same in Sitzungsberichte der Gesellschaft naturfor.schender Freunde in Berlin, 1879,
pp. 53 and 140.

■■ Henry K. Slater. — On a new genus af Pycnogon {Para::dcs) and a variety of Pijcnoyonum littorak from Japan,
Ann. and Magaz. of Nat. History, 5th series, vol. iii., 1879.

'' Boston Jouinal of Natural History, i. 204, t. 7. (See Cuvier's Animal Kingdom, London, Wm. S. Orr & Co.
1840. p. 468.)

" Proc. Boston Society Nat. Hist., vol. i. p. 92.

' Gay.— Historia fisica y politica de Chile, Zoologia, p. 308, pi. iv. fig. 8, 1854.

REPORT ON THE PYCNOGONIDA.

not to be the work of one who begins to study a group, as is often the case, but can
only be done properly after laborious and continuous research. Moreover, the stud)^ of
the literature is enormously encumbered by the circumstance, that descriptions of single
species often lie buried in obscure periodicals. This cii'cumstance, I hope, will ]je
considered, when my report is found to be far from complete.

The collection of Pycnogonida brought home by the Challenger and placed in my
hands numbers about 120 specimens. They were in an excellent state of preservation,
and to facilitate the work, the bottles of spirit in which they were put, were furnished
with labels indicating the station, latitude, longitude, bottom temperature, and the
natm'e of the sea-l^ecl where they were dredged. Some of the specimens were not
obtained from any of the 361 dredging stations, but were collected on the shore (near Cape
Town, e.g.), or dredged in shallow water (Bahia, Kerguelen). Over a course of 68,890
miles the dredge was let down at 361 stations, and Pycnogonids were procured on only
twenty-six occasions. The 120 specimens of Pycnogonida brought home belong to
thirty-six species, and thirty-three of these I have been obliged to consider and describe
as new to science. The greatest depth where a Pycnogonid was found was 2650 fathoms;
the greatest depth dredged during the cruise was 4575 fathoms.

In the following list I have given the range in depth at which species of Pycnogonida
were found by the Challenger, and also recently during the cruise of the " Knight
Errant":—

Discoarachne brevrpes, Hoek.

Hannonia typica, Hoek.

Phoxichilidium flumiriense, Kroyer.

Phoxicliilidium insigne, Hoek.

Nijmplwn bracJii/rhynchiis, Hoek.

Nymphon hrevicaudatum, Miers.

Nymphon fuscitm, Hoek.

Ascorhynclms minutus, Hoek.

Pallene langnida, Hoek.

Pallene laevis, Hoek.

Pallene aimtraliensis, Hoek.

Plioxicliilidiuin paiaijonicu'in, Hoek.

Pycnorjonum liforale, Strom.

Colossendeis megalunyx, Hoek.

Nymphon hrevieollnm, Hoek.

Nymjihon grossipes, Oth. Fabr., sp.

Colossendeis rolnista, Hoek.

Ascorhijnchus orthorliynclms, Hock.

Nymphon robustum, Bell.

Colossendeis leptorhynelms, Hoek.

Nymphon stromii, Kroyer.

Nymphon macronyx, G. 0. Sars.

Colossendeis prohoscidaa, Sab., sp.

Phoxichilidium pafagonimm, var. elegans, Hoek.

Shore,

J) •

7 to 20 fathoms,

)J J)

))

10 to 120

n

2.5 to 120

»»

25

J)

38

)»

J)

»»

38 to 40

>j

38 to 120

))

45, 55, 175

n

53

»>

55, 70, 120

»)

83

))

83 to 540

»)

120 .

1)

150 .

>>

375 to 540

))

400 to 1600

))

51.5,530,540

))

540

600

8

THE VOYAGE OF H.M.S. CHALLENGER.

700 fathoms,

Oorlujnclius aucJihmdice, Hoek.

825

?> •

Nymphon perhicidum, Hoek

1100

J)

Nymplion longicoxa-, Hoek.

)) '

)?

Nymphon compadum, Hoek.

1250

))

Colossendeis minuta, Hoek.

1375

u

Astiorhynchus glaher, Hoek.

1375 to 1600

j>

NyniiJlion hamatum, Hoek.

J) )>

J)

Colossendeis gigas, Hoek.

)J J5

J)

Colossendeis gracilis, Hoek.

1600 to 1950

J)

Phoxichilidium pUosum, Hoek.

1675

»

Nymphon meridionale, Hoek.

jj '

«

Phccichilidium oscitans, Hoek.

1875

>)

Phoxichilidium mollissimum, Hoek

2160

;j

Nymphon procerum, Hoek.

2225

))

NymjJhon hngicollum, Hoek.

))

Colossendeis media, Hoek.

2650

J)

Colossendeis hre.vipes, Hoek.

The number of times at which Pycnogonida were dredged at certain depths is shown
in the following table : —

99 dredgings in depths of from 1 to 500 fathoms,

26 times.

30 „ „ 501 to 1000

n •

3 „

47 „ „ 1001 to 1500

)j

3 „

47 „ „ 1501 to 2000

?)

4 „

93 „ „ 2001 to 2500

)j

2 „

83 „ „ 2501 to 3000

))

Once (at 2650 fathoms)

11 „ „ 3001 to 4575

)»

None.

It thus becomes apparent that what Davidson has shown for the Brachiopoda,
holds also in the case of the Pycnogonida, that they are very seldom found in depths
exceeding 500 fathoms ; out of about 100 dredgings in depths of from 1 to 500 fathoms,
Pycnogonids were brought up twenty-six times, while in depths varying from 501 to
3000, they were obtained only thirteen times out of 300 dredgings.

The following statement shows the range in depth at which the genera of Pycnogonida
hitherto known have been found. The total number is twenty-seven genera, of which
eleven are true Httoral forms. Of the sixteen remaining genera there are five
of which I am quite uncertain as to the depth at which they are found, and
four for which the depth does not exceed 50 fathoms. Then there are two {Pallene
and Pycnogonum), which, as a rule, inhabit depths not exceeding 120 fathoms, but
which in a single case were found at depths almost reaching 500 fathoms (Pallene
malleolata, G. 0. Sars, at a depth varpng between 191 and 459 fathoms, and P«/c?;o-
yonum litorale, dredged hj Smith and Harger, at a depth of 430 fathoms). Hence
there remain only five genera of Pycnogonida, species of which may truly be called
deep-sea inhabitants; they are the gcnern Nymphon, Ascorhyncliiis, Oorhynchits, Colos-
sendeis, and Phoxichilidmm.

REPORT ON THE PYCNOGONIDA.

9

List of the Genera of Pycnogonida hitherto known.

Name of the Genus.

Number

of
Species

De-
scribed.

Depth in Fathoms

at wliich they have

been found.

Geographical Distribution.

Nymphon, Fabr.,

38

Shore to 2225.

Mundane — Pacific Ocean excepted.

Ammothea, Leach,

5

Shore to 5.

American and European Coasts of the North
Atlantic.

Bohmia, Hoek, .

Phonodemus, Costa, .
Rhynchothorax, Cos., .
Pepliredo, Goodsir,
PlatyrliehiS, Cos.,
Oiceohi-dlirs, Hesse,
Ascorhyncltus, G. 0. Sars, .

1

3
1
1

1
1
5

Shore.

Shore.

(})

Shore.

38 to 1539

a)

Coast of Italy.
North Coast of Africa.
Coast of England.
Coast of Sardinia.
Coast of France.

North Atlantic, Indian Ocean, South Coast of
Australia, North of New Guinea. Coast of

Zetes, Krciyer, .

I

Shore.

Japan.
Coast of Greenland.

Parazetes, Slater,
Pariboea, Philipjii,
Achelia, Hodge, .

1

1
4

(?)
Shore.

Shore to 35.

Japan.

Coast of Italy.

American and European Coasts of the North

Atlantic, Coasts of the Mediterranean, Ker-

guelen.

Alcinous, Cos., .
Tanystylum, Miers, .
LecWwrhynchus, Bbhm,
Oorhynchus, Hoek,
Colussendeis, Jarzj'nsky,
Pasithoe, Goodsir,

2

2

2

1

12

1

0)

5 to 7

3 to 4

700

55 to 2650

Shore.

Coast of Italy.

Kerguelen, East Coast of North America.

Japan.

Auckknd.

JNIundane — Pacific Ocean excepted.

Coast of England.

Endeis, Philippi,
Discoarachne, Hoek, .
Pallene, Johnston,

2
1
16

Shore.

Shore.

Shore to 459.i

Coast of Italy.
Coast of Cape Colony.

Coast of Northern Europe, Greenland Sea,
Coast of Greenland, East Coast of North

PhoxicMKdium, M. -Edwards,

15

Shore to 1960.

America, Coast of Mozambique, off Australia,
China Sea, Coast of Japan.
Coast of Northern Europe, Greenland, North
America, North Atlantic, Coast of Brazil,
Patagonia, South Atlantic, Indian Ocean,

Oomerus, Hesse,
Hannonia, Hoek,
Phoxichilus, Latr.,

Pycnogomim, Briinnich,

1
1
4

2

Shore.
Shore.
Shore.

Shore to 430.-

Coast of Lower Siam, off Japan.

Coast of France.

Coast of Cape Colony.

Coasts of Northern Europe, Mediterranean Coast,
Coast of Lower Siam.

Coasts of Northern Europe, East Coast of North
America, Coast of Chili, Coast of the Mediter-
ranean, Coast of Australia.

' Teste G. O. Sars.

(ZOOL. CHALL. EXP. PART X. — 1881)

^ Smith and Harger, teste Wilson.

K 2

10 THE VOYAGE OF H.M.S. CHALLENGER.

When comparing the bathymetrical range of the different genera -n'ith their
o-eographical distribution, it is easily remarked that it is the genera most widely
spread over the bottom of the sea which are capable of existing at the greatest
variety of depth. This is, for instance, the case with Nymjjhon, Colossendeis, and
Phoxichilidmm. Some species of Nymphon are found at low-water mark, others
inhabiting shallow water in the immediate neighbourhood of the coast are dredged at
a depth of under 100 fathoms ; others again are never found at a depth exceeding 800
fathoms, and finally, there are some which are true deep-sea species. Some species of
Colossendeis were dredged at a depth of under 100 fathoms, other species inhabit the
ocean at a depth not exceeding 800 fathoms, and others were cbedged at depths varying
from 800 to 2800 fathoms. The genus PhoxichiUdium shows almost the same bathy-
metrical range as Nymphon. Now the geographical range of these three genera is, as
far as I could ascertain from the facts at my disposal, nearly the same ; this distribution
is mundane. With the exception of the Pacific Ocean, from which as yet not a single
species of Pycnogonid has been obtained, representatives of these three genera are found
almost in every sea.

Of the genus Ascorhynchus only five species are known as yet. They were collected
at depths varying from 38 to 1539 fathoms, and at widely distant places, viz., in the
Greenland Sea, between the Cape of Good Hope and Kerguelen Islands, off AustraUa, to
the north of New Guinea, and off Japan ; and as the different species of this genus form
a very natural group, it is, I think, very probable, that later investigations will show also
for interjacent places the occurrence of forms belonging to this same group. Oorhynchtis
is as yet the only genus which seems to inhabit depths exceeding 800 fathoms exclusively ;
but as only a single specimen of the one species known of this genus has been collected, I
do not think it expedient to pay much attention to this fact.

Hence, with regard to the bathymetrical range, a close study of the mateiial brought
home by the Challenger, added to what was previously known on the subject, has
shown : —

(1) That those genera which range most widely geographically are also those which
range most widely in depth ; and (2), that there does not seem to exist a single true
deep-sea genus of Pycnogonids.^

As for the influence of the increasing depth on the form and the structure of our
animals, this is by no means easily traced. As far as the structure of the integu-
ment and of the eyes is concerned, I will treat the question at some length when speak-
ing of their structure. As a rule the true deep-sea species are more slender, the legs very
long and brittle, and the surface of the body smooth, whereas the true shore-inhabitants
are much more concentrated, have shorter legs, and are often densely covered with

1 From the study of deep-sea forms in general, Jlr Moseley and others came to the conclusion that these animals
have a world-wide range. Of this the Pycnogonids give a fair instance, I believe (Moseley in Nature, April 8, 1880
p. 546).

EEPORT ON THE PYCNOGONIDA. 11

hair. However, these rules admit of a great many exceptions. Thus the most common
shallow-water species of the English, French, and Dutch coasts is Nymjylion gracile,
Leach, an exceedingly slender animal with very long legs, and moreover almost smooth.
Colossendeis prohoscidea, Sab., sp., is a blind species occurring only at a considerable
depth ; yet it has a highly concentrated body with short legs. Two species of Phoxi-
chilidium, for which I have proposed the names Phoxichilidium pilosum and Phoxichili-
dium moUissimum, are true inhabitants of the depths of the ocean ; yet they are not
smooth at all, but covered by a very hairy integument. The case of Phoxichilidium pata-
gonicum and its variety elegans, which I describe hereafter, must probably be considered
as a trifling instance of the efl"ect of depth on the slenderness of the body.

The scientific and trustworthy material at our disposal is by no means sufficient
to enable us to discuss thoroughly the question of the geographical distribution of
Pycnogonids. Judging from what is known of the European and North American
coasts, it is most probable that on all coasts, and everywhere in shallow water in the
neighbourhood of the shore, forms of Pycnogonids will be found occurring ; and as I
think it improbable that any true shore-inhabitant will be found which shows a very
wide range, it is also highly probable that the number of littoral forms at present known
is very small in comparison with the number really existing.

The distribution of those Pycnogonids which are not to be considered as shore-
inhabitants, but which have never been dredged yet at depths exceeding 500 fathoms,
is best known in the northern part of the Atlantic and the seas corresponding with it
(North Sea, Greenland Sea, Barents Sea). The species of the genus Nymphon, which
occur in the neighbourhood of the coast of New England, are found to the north and
east as far as Greenland, Spitzbergen, and Novaja Semlja ; but these Arctic Seas are,
moreover, inhabited by some forms of the same genus occurring there only. As this
point has been more fully discussed by me in another paper, it will suffice merely to
mention it here.

Among the Pycnogonids of the Challenger Expedition, Colossendeis megalomjx,
Hoek, is the only species, which, though found at a depth of from 55 to 120 fathoms, has
a wide range ; about the 58th south parallel it was dredged off Kerguelen Island, and
also between Patagonia and the Falkland Isles.

With respect to the true deep-sea species the material is by no means sufficient for
the study of their geographical range. Of the thirty-six species of Pycnogonids brought
home by the Challenger, nineteen are true deep-sea species. Of these only three belong
to the northern hemisphere, viz., Colossendeis miniita, Hoek, south of Habfax ; Phoxichi-
lidium oscitans, Hoek, west of the Azores ; and Phoxichilidium moUissimum, Hoek, off
Ycddo ; they were only dredged once and were new to science. Of the remaining sixteen,
which belong to the southern hemisphere, one was dredged at lat. 65° 42' S.
{Nymphon meridioncde, Hoek) and one almost under the equator {Nyvphon per-

12 THE VOYAGE OF H.M.S. CHALLENGER.

lueidum, Hoek, at lat. 0° 48' S.). The fourteen remaining species were all dredged
between lat. 33° 31' S., and lat. 53° 55' S. ; and it is a remarkable fact, that those
two latitudes limit a zone of about 20°, in which Pycnogonids seem to be rather
common. However, even in this zone they are again much localised, being almost
in every instance from near the coast of an island or continent. For miles the dredge
was let down without bringing up a single specimen ; whereas six species were found
occurring at Stations 146 and 147, off the Crozets Islands (these Stations being very
near to one another, I take as one) ; one at Station 157 ; three east of New Zealand,
at Stations 168 and 169; five between Juan Fernandez and Valparaiso (Stations 298,
299, and 300) ; and two east of Buenos Ayres (Stations 320 and 325).

These facts indicate, I think, that the number of places inhabited by deep-sea
Pycnogonids are not very numerous, and that where Pycnogonids do occur,
many forms are, as a rule, found living together. This also ought to be observed
when considering that between Stations 237 (ofi" Yeddo) and 298 (between Juan
Fernandez and Valparaiso), throughout a course of 11,775 miles, the dredge was let down
sixty times and not a single Pycnogonid was obtained. This of course may partly be
ascribed to the circumstance, that on an average the depth of that part of the ocean is
too considerable to be inhabited by Pycnogonids ; but as the depth at many stations
during that part of the voyage did not exceed the depths of other stations at which
Pycnogonids were dredged, this cannot be considered as the only reason. Also when the
same circumstance is found to be the case in that large part of the South Atlantic between
the Azores and Station 146, where during a course of more than 9000 miles the dredge
was let down at 76 stations without a single return of Pycnogonids, and this although
the depth at these stations is less, and at most of them much less, than some of the
greater depths at which Pycnogonids were found, it is quite evident that the depth of
the sea alone cannot be held responsible for it. Nor do I consider it yet proved that
Pycnogonids are totally wanting in these oceans, as only a very small area of these oceanic
abysses has been explored ; so I think the only conclusion which at present may be
drawn is this, that as yet only a few of the places where Pycnogonids occur in great
numbers have been found out.

In regard to the nature of the bottom from which the Pycnogonids of the Challenger
Expedition were obtained, conclusions must be also somewhat uncertain. The bottoms
on which they occur seem to be extremely different. We find that one species
was brought up from a bottom of gravel and stones, one from hard ground, one from
. rocky ground, five species are recorded as having been brought up from a muddy bottom,
one from diatom ooze, five from a sandy bottom, three from a bottom of grey ooze, three
from grey mud, and three from globigerina ooze. The other species were obtained from
rocky bottoms in the neighbourhood of the shore.

JMore particulars about the geographical and bathymetrical distribution of the

EEPORT ON THE rYCNOGONIDA.

13

Pycnogonids may be found in the list of the species hitherto described, which I append
to this report. I have tried to make it as complete as possible ; yet it contains many
species of which no information is given as to the depth at which they were found ; others
of which even the locality they inhabit is not accurately stated; and futhermore, there
are genera and species — and of the latter no small number — about which we are totally
left in the dark. To explain this the reader must keep in mind (l) that this is the first

Inimovablf claw

Movable claw

■^f^IPj.'^.l'-..- 3ril cosal joiat of the leg
, Paliftis

Proboscis

Cephalic part of the cephalothorncic segment

Isb

2ud cosal joiut
3rd
Thoracic part ot the'

cephalothoracic seErmen

lat tarsal joiut

2nd thoracic sfgment

3rd thoracic segment

2n<\ tarsal joint

4//i thoracic segrnmil

Abdnmen

Claw

3

Tliigh

A

JUT 2iid coxal ioiiit
^••-,^r of the leg

^^r 2ad tibial joint
^. ... 1st cosal joiut of the leg

^'m

ll

tubercle>^

1st tibial joiut

lateral processes for the iu^eittuu of the k^s

Ovigerous Ug

. 2nd tibial joint

Nymiilion, &\>. *

attempt to make such a list, with the exception of a very incomplete and superficial
enumeration published in 1874 by Semper/ and (2) that there is as yet no paper
published which discusses the relative value of distinguishing marks. So it is evident
that the making of this list has been an exceedingly troul)lesome affair, and that some
allowance may be made for its incompleteness.

' For reasons easily to be understood I have taken a species uf Nymphon as the type.

2 C. Semper, Ueher Pycnosoiiiden und ihre in Hydroid-Polypeu sohmarotiieuden Jugendformeu. Arheiten des ZoiA.
Zoot. Instituts in AViirzbury, Band i., 1874.

14 THE VOYAGE OF H.M.S. CHALLENGER.

Before inserting this list I wish to give a short description of the body of a
Pycnogonid, and at the same time to state the nomenclature I have made use of.

The body of every Pycnogonid consists of four segments, the first of which is to be
considered as formed by the connection of the head with the first thoracic segment. At
the anterior end this first segment is furnished with a long and stout proboscis. This
proboscis is situated either about the front of the first segment, as in Nymphon,
and in this case is capable of very limited motion, or as in Ammothea and Ascorhynclms,
though also situated about the front, it is connected with the segment by means of an
articulation, and for that reason is highly movable, or it is, as in Phoxichilidium,
situated on the ventral surface of the first segment, and bent forward ; or finally, it is
situated about the ventral side, and at the same time lapped over it {BdJimia, mihi).
The form and size of this proboscis varies greatly. At its extremity it is furnished with
a triangular mouth. It is to be considered as an unpaired outgrowth of the region
surrounding the mouth, and has nothing to do wdth a true head, as was supposed by
Savigny. Neither is there anatomically or embryologically any real ground for the
opinion, suggested by Huxley,^ that the proboscis represents the united chelicerse
and pedipalpi like that of Acarina.^

The cephalic part of the cephalothoracic segment is generally furnished with three
pair of appendages, which long ago received the names of mandibles, palpi, and
ovigerous legs. As far as has been ascertained till now, there is not a single genus of
Pycnogonid, which does not show these three pair of appendages either in the adult
state, or during its embryological development. Yet cases are not rare, in which in
the adult animal, either the fu-st (the mandibles) or the second pair (the palpi) or both
are deficient. With respect to the third pair of appendages (the so-called ovigerous legs),
on the contrary, they are never found wanting, as far as we know, in the adult animal
of either sex. Whoever studies different forms of Pycnogouids, will soon discover what
a difference may be caused in the appearance of the cephalic part of the body by the
presence or absence of the cephalic appendages ; hence it is that the various authors
who have proposed a classification of the group have largely made use of this presence
or absence of cephalic appendages. Although there is no doubt, I believe, that good
characteristics may be derived from the numljer of these appendages, the following may
show how extremely necessary it is to be cautious in this matter.

^ Huxley, Anatomy of Invertebrated Animals, p. 386, London, 1877.

2 On a tranverse section, the proboscis of the Pycnogoliids always shows a more or less distinctly triangular
shape, the mouth is also triangular, &c. The total form, therefore, is to be compared with the fruit of a monocotyle-
donous plant, composed of three carpels. Of these one is placed dorsally, the two others meet longitudinally in the
middle of the ventral side. If anybody should feel inclined to try again to homologise the proboscis with cephalic ap-
pendages, he will have to call the dorsal piece the labrum, and the two others the homologues of mandibles. However, in
the earliest stages of development I have observed, the proboscis has ab-eady the form of a short cylindrical appendage,
and I must poLat out the anatomical fact that the proboscis for the greater part is innervated from the .'jupraceso-
phageal ganglion.

REPORT ON THE PYCNOGONIDA. 15

The mandibles in some genera are two-jointed {Nymplion, Pallene, &e.), in others
three-jointed {Phoxichilidium). As a rule the second or third joint terminates in
a pair of pincers, with a movable and an immovable claw. Now there are genera, some
species of which show the mandibles small, yet furnished with true pincers, whereas
other species of the same genus show the mandibles in a mucli more rudimentary state,
as if, for instance, represented only by a single joint terminating abruptly [Ascorhynchus
glaher, Hoek, and A. minutus, Hoek). In other genera the mandibles are in the adult
animal always rudimentary, represented only by short stumps {Lecithorhynchus, Bohm,
Oorhynchns, Hoek, &c.) ; whereas in a fourth category the mandibles have totally
disappeared {Colossendeis, Phoxichilus, Pycnogonum, &c.). Among the specimens of a
species of one of these genera {Colossendeis gracilis, Hoek), dredged during the cruise of
H.M.S. Challenger, I have, however, found one specimen furnished with a pair of
distinctly three-jointed mandibles, terminating in a pair of pincers ; and this specimen
was the largest of the three obtained.

The palpi when present show very different numbers of joints. Thus there are
only three in Pefhredo, five in Nymiilion and Discoamchne, eight in Achelia, nine
in Ammothea and Corniger, ten in Ascorhynchus, Colossendeis, &c. The palpi have
disappeared in the genera Pallene, Phoxichilidium, Phoxichilus, Pycnogonum, &c.
In Phoxichilidium they are as a rule still represented by rounded lateral processes
placed at both sides of the front part of the cephalothorax, whereas Bohm has observed
a specimen of Pallene furnished with rudimentary, yet distinct two-jointed palpi.

The third pair of appendages, viz., the ovigerous legs, are never wanting in any
species of Pycnogonids. Among the Pycnogonids of the Challenger, there is not even
a single specimen without ovigerous legs ! As a rule they are ten-jointed ; the first three
joints are extremely small, the two following are the longest of all, the sixth joint is a
great deal shorter, the last four joints are much shorter still, the tenth joint as a rule
is furnished with a claw. In some genera {Colossendeis, e.g.) the fifth joint is small,
the sixth as long as the fourth joint. In those genera, where a certain tendency is
observed to drop their cephalic appendages, the ovigerous legs share this fate only to a
small extent. As the functions of the ovigerous legs are twofold, one being to bear the
eggs, a function only accomplished by the male,' the other to serve as an organ of feeling,
also, in all probability, of seizing the food, and as the latter of these functions is almost
identical with that of the other cephalic appendages, it is quite natural, I believe, that,
whereas the males are never seen without these appendages, they are wanting in the
females only of those genera which have also lost their other cephalic appendages.
Finally, it is evident, that the males of those latter genera ought to show the ovigerous
legs in such a rudimentary state, as to be fit only for the ovigerous function.

DorsaUy the front part of the cephalothorax bears the oculiferous tubercle ; although

' Hereafter I will show that this rule admits of an exception. See under Nymphon brevicaudatum, Miers.

16 THE VOYAGE OF H.M.S. CHALLENGER.

in many instances — especially in the true deep-sea species — the eyes are wanting (a
matter to he discussed hereafter), it never happens that the tuhercle has totally dis-
appeared. Most genera have this tuhercle placed nearly in the middle between the two
ovigerous legs ; but in some genera [Phoxichilidium, e.g.) it is situated much nearer
the front of the segment.

The thoracic part of the cephalothorax and the three following true thoracic segments
are furnished with lateral processes for the insertion of the legs ; these lateral processes
in the diiferent genera, and even in different species of the same genus, are of very differ-
ent lengths. The segments of the body themselves are also of very different lengths.
There are extremely slender forms with long segments and widely separated lateral
processes, and there are also forms so highly concentrated, that the lateral processes
are not separated at all ; and between these extremes, which are often met with in one
and the same genus, numerous intermediate forms are to be observed. The dorsal
surface of the body is either smooth or furnished with knots, spines, strong prickles, &c.

At its extremity, between the two lateral processes for the insertion of the last
pair of legs, the last thoracic segment has a rudimentary abdomen of varying length,
which is sometimes {Colossendeis, e.g.) connected with the segment by means of an
articulation, and also sometimes {Zetes, Kroyer) shows traces of being divided into
two segments.' At its extremity the anal aperture is found.

The legs begin at the ends of the lateral processes ; they are eight-jointed. For the
joints I retain the names proposed by Johnston ; these names are the same as those used
in entomology, but it is evident that in this case identity of name does not necessarily
go along with identity of meaning ; neither analogical nor homological comparison is
meant by it.

The first three (the coxal) joints are as a rule very short ; the following three, the
thigh and the two tibial joints, are much longer (the second tibial being in most cases the
longest of all). The two tarsal joints are again a great deal shorter. The first tarsal
as a rule is shorter than the second ; in many instances it is even extremely small, its
function then being only to furnish a highly movable articulation to the last joint of the
leg. At its extremity the last joint is furnished with a claw, which is, or is not, accom-
panied by two accessory claws.^ In some genera {Colossendeis, e.g.) accessory claws are
never observed, whUe in other genera (NympJion) they occur in some species and are
wanting in others. Therefore the presence or absence of accessory claws alone should
not be made use of in establishing new genera.

' Ehynchothorax viediterraneus, Cos., Microdoride mediterranea, Napoli, 1861, has a seven-joiuted abdomen (Addome
angusto e brevissimo di 7 articoli).

2 I think there is not a single reason for calling this claw a ninth joint. At any rate the homology of the claw with its
accessory claws is much greater than that between the claw and the joints of the leg, and, therefore, if the claw is con-
sidered as a ninth joint in those cases where accessory claws are observed, we must speak of a joint ha^•ing two lateral
joints close to its origin, which would be absurd.

EEPORT ON THE PYCNOGONIDA.

17

Catalogue of the Species of Pycnogonida at present known, with Indications
OF THE Habitat and Eange in Depth of each Species.

A point of interrogation has been placed before uncertain or not sufficiently deter-
mined species, and an asterisk before those dredged by the Challenger Expedition, and
during the cruise of the " Knight Errant " ; of these a full description is given hereafter.
In the left-hand column the range in depth of each species is given.

Class PYCNOGONIDA, Latr.

Crustacea haudeUaia, Johnston ; Crustaces araneiformes M.-Edw. ; Podosomata, Leach ; Pantopoda, Gerstecker.

Family I. Nymphonid^
Contains those Pycnogonida which have both mandibles and palpi strongly developed.
The ovigerous legs are always present in both sexes, and are, as a rule, furnished with
denticulate spines. The only genus : Nymphon.

Depth in Fathoms,

Name.

Geographical Distributiou.

Nyinplwn. Fabr. (1794)
Mandibles biarticulate, cheliform ; palpi, five-jointed ; ovigerous legs,

ten-jointed.

A. Species with auxiUary claws.

10 to 15 Nymphon hirtipes, Bell, Belcher, The Last of the Arctic

(:Miers). Voyages, vol ii. p. 408, 1855. Prof. G. 0. Sars

33 (Bell). (1877) considers this species to be the same as N.

48 to 50 hirtum, Fabr., which in that case would not be identi-

(Wilson). cal with N. hirtum, Fabr., as described by Kroyer

52 (U. S. (1845). As it is impossible to recognise the species

Fish. Com.). by the description of Fabricius, I think it safest to

299 (Sars). retain the name N. hirtum for the species of Kroyer

whose description was published long before Sars'
Prodromus. N. hirtum, Fabr., Sars, in Prodromus
descriptionis, &c. (Arch, fur Math, og Nat, ii. 1877).
N. hirtipes, Bell, Wilson, Pycnogonida of New Eng-
land, Trans. Connect. Acad., vol. v., 1880. Having
received from the U. S. Fish. Commission a specimen
brought up off Halifax, I feel certain that the animal
described by Wilson belongs to this species. Finally,
I believe that the specimens studied by Miers, and
referred by him to K hirtum (Arctic Crustacea in
Ann. and Mag. Nat. Hist., 4th series, xx. 108, 1877)
belong to this species and not to N. hirtum, Fabr.
The N. hirtum, var. obtimdigitum, Miers, seems to be
an undevokiped female of the same species.

(ZOOL. CHALL. EXP. — PART X. — 1881)

Lat. 64° 36', long. 10' 21' 5".
Ofl' Halifax ; Franklin-Pierce
Bay ; Discovery Bay ; Flre-
berg Beach; Northumberland
Sound. " Appears to be a
common inhabitant of the
high northern latitudes "
(Miers). (A common species
at different stations in the
Barents Sea. Hoek, in MS.)

K 3

18

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

Name.

Geographical Distribution.

80 to 90

15 to 65

(Bohm).

25 to 1-20

(Challenger).

10 to 80
(Miers).
35 to 90

(Wilson).

515 to 540

(" Knight-
Errant ").

110 to 160

(liarents Sea,

Hoek in

MS.).

Nymphon pallenoides, G. 0. Sars, Crustacea et Pycno-
gonida nova, Arch. f. Math, og NaturviJ., iv., 1879,
p. 470. Of this species Sars says that it is N. hirsuto
affine, sed statura minora, &c. Perhaps it is only a
local variety. As Sars does not mention the length of
the auxiliary claws, I feel uncertain whether it is
nearest to iV. hirtipes, Bell, or N. hiiiiun, Fabr.
(Kroyer).

Nijinphon hirtum, Fabr. Entom. Systematica, iv. 417,
1794. N. hirtum, Chr. Fabr. (^), Kroyer, BiJrag, &c.,
Nat. Tidskr., N. E. i. 113, 1845. The description
of Fabricius being quite insufficient, I retain the
species with the diagnosis of Kroyer. Perhaps N.
Jiirgutus, Sabine (Appendix, &c., p. ccxxvi, 1824),
belongs also to this species ; according to Kroyer this is
doubtfuL N. hirtum, 0. F. Buchholz, Crustaceen der
Zweiten Deutschen Nordpolarfahrt, 1874, ii. 397.
In regard to N. hirtum, Fabr. Heller (Crust., Pycnogon.,
und Tunioaten der K. K. Ost.-Ung. Nordpol. Exp. in
Denkschr. d. Kais. Akad. d. Wiss., Bd. xxxv., 1875),
it is impossible to determine whether it is this species
or N. hirtipes, Bell, that was observed.
*Nympihon hrevicaudatum, Miers, Ann. and Mag. of Nat.
Hist., 4th series, vol. xvi. p. 117, 1875). Crustacea
of Kergnelen Island, Phil. Trans. Loud. vol. clxviii.
Extra vol., pp. 200-214, 1879, pi. xi. fig. 8. N.
horridiim, Bohm, Pycnogoniden des Museums zu
Berlin, Monatsber, der Kcinigl. Acad. d. Wiss. zu
Berlin, 1879, p. 175, taf. i. fig. 3-3/ Bohm's suppo-
sition that his A'', hon-idum was indentical with Miers'
N. hrevicaudatum is true, as has been proved by the
more extensive description with illustrations published
by Miers in 1879 in the extra vol. of the PhiL Trans,
of London. Many specimens of this .species were
obtained during the visit of H.^I.S. Challenger to
Kergnelen.
*Nijmphon stroyiui, Kr., Nat. Tidskr., N. E., vol. i. p. Ill,
1845. Wilson (Pycnogonida of New England, Trans.
Connect. Acad., vol. v. p. 17, 1880) believes that the
N. gracilipes, Heller (Crust. Pycnog. und Tunic, des
K. K. Oester.-Ungar. Exped. Denkschr. d. K. Ak. der
Wiss., xxxvi., 1875) — not to be confounded with the
N. gracilipes, Miers, and therefore named by Bolim
(Pycnogoniden des Museums zu Berlin, Monatsb. der
K. A. d. Wiss. zu Berlin, p. 170, 1879) TV. Helleri— is
very closely allied if it is not identical with this
species. This is also my opinion, although Heller in his

Coast of Norway (Saltenfjord).

Norwegian Ocean, Iceland, East
Coast of Greenland (Bohm,
Pycnogoniden des Museums
zu Berlin, 1879) ; East Coast
of Greenland (Nordshannan),
S torfjord (Spitzbergcn), Buch-
holz, loc. cit.

Koiguelen.

Coast of Norway'! (Kroyer),
North Atlantic (Sars and
" Knight Errant " cruise),
Barents Sea (Hoek in MS.),
"An verschiedenen Punkten "
(Heller, i.e., during the
Austria-UngarianNorth Polar
Exped. of 1873); Flffiberg
Beach, Cape Eraser, Grinnel-
land (Miers), Coast of North
America,Gulf of StLawrence,

REPORT ON THE PYCNOGONIDA.

19

Depth in Fathoms.

(?)

Name.

412

540 (" Knight
Errant")

83

45 to 120

1G75

10 to 45

diagnosis of his species says : unguiculi auxiliares nulli
(p. 40). A considerable number of specimens of this
species have recently been dredged (North of Scotland)
during the cruise of the " Knight Errant." One of the
commonest species in the northern part of the Atlantic.
(1) Nymphon giganteum, Goodsir, Ann. and Mag. of Nat.
Hist., vol. XV. p. 293, 1845. Goodsir's description is
not sufficient to determine this species. Wilson
(Pycnogouida of New England, Trans. Connect. Acad.,
vol. V. p. 16, 1880) considers this species as identical
with the N. dromii of Kroyer. As Goodsir does not
even say whether the body is slender or robust, it is
extremely difficvdt to ascertain whether or not Wilson's
suggestion is right.

*N(jmphon macronyx, G. 0. Sars, Prodromus, Arch. f.
Math, og Naturvid., ii. 365, 1877. I know this
species by the description of Prof. Sars, from a pencil-
drawing he kindly sent me, and feel sure it is a good
sjjecies. Recently I had a fair opportunity of becom-
ing acquainted with it, as numerous specimens were
dredged north of Scotland, and forwarded to me by Mr
Murray. As only a very short diagnosis of this
species has been given by Prof* Sars, I will publish
hereafter a detailed description of it.

* Nymphon hrevicollum, n. sp. A fine, well-characterised
species.

*Nymphon hrachyrliynchus, n. sp. A small but well-char-
acterised species, which seems to abound at a depth of
45 to 120 fathoms.

* Nymphon meridionalc, n. sp., shows a certain affinity to N.
gracilipes, Miers (Ann. and Mag. of Nat. Hist., 4th ser.,
vol. xvL p. 76, 1875) ; so the latter species may be con-
sidered as a shore-relation of this true deep-sea species.

Nymplion gracilipes, Miers, Ann. and Mag. of Nat. Hist.,
4th series, vol. xvi. p. 76, 1875. N. gracilipes,
Miers, Bohra, Pycn. des Mus. zu Berlin, Monatsb. der
K. Akad. der Wiss. zu Berlin, p. 170, 1879. N.
antarcticum, Miers, Crustacea of Kerguelen Island,
Phil. Trans. Lond., voL clxviii. Extra vol., p.
200-214, pi. xL, 1879. This species seems to be a
good species. Miers thought it necessary to alter the
name he originally proposed, because in the same year
the same name was given by HeUer to an arctic
species. The N. gracilipes, Heller, being only a
synonym of the N. strdmii, Kr., I think it best to
retain this name for the Kerguelen species, as was
originally projjosed by Mr Miers.

Geographical Distribution.

off the Isles of Shoals,
HaHfax (Wilson).

off

Sea at Embleton, Northumber-
land.

Lat. 62' 44' 5" N, long. 1°
48' E. To the north of
Scotland.

South of Halifax, Station 49,

Challenger Expedition.
Kerguelen.

South of Kerguelen Island, lat.
65° 42' S., long. 79° 49' E.,
Station 43, Challenger Ex-
pedition.

Kerguelen.

20

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

120
2225

1 to 2

229 ; 417

Name.

Geographical Distribution.

825

GO (Wilson)

220 (Saiv)

67 (Hoek in

MS.).

Shore; " ma-
jores etiam
in prof undo"
(Otli. Fabr.
Fauna
Groenl)

50,20 to 100
(Wil.?on)
83 (Clial-
lenger).

540 ("Knight
Errant".

'■-Nynqyhon fnsnim, n. sp. This species too seems to be

closely allied to N. gracilipes, Miers.
*N'//mpJion longicoUum, n. sp. The only specimen of tliis
true deep-sea species shows very characteristic fea-
tures.
Niimplion gracile, Leach, Zool. Misc., vol., i. p. 45, 1814.
N. gracile, Leach, Johnston, An Attempt, &c., in Mag.
of Zool., 1837. N. gracile. Leach, Hoek, Ueber
Pycnogoniden, Nied. Arch. f. Zool., iii., 1877. It
has been suggested by Kroyer that it might be the
same as N. grossiiies, 0. Fabr., but I prefer to retain
the name of Leach for the species as known by the
description and figures of Mr Johnston and myself,
which is distinct from N. grossipes, O. Fabr., as de-
scribed by Kroyer.
Nymphon megalops, G. 0. Sars (Prodromus descriptio-
nis, &c.. Arch. f. Math, og Katurvid., ii. 366, 1877).
Not figured. Prof. Sars kindly sent me a pencil-
drawing, and from this drawing and liis Latin diagnosis
I believe the species is nearly related to N. gracilijies,
Miers.
* Nymphon perlucidum, n. sp. A very well-characterised
species, of which, unfortunately, only one specimen was
dredged by the Challenger.
Nymphon longitarse, Kr., Bidrag till Kundskab, Natur.
Tidskr. N. R, i. 112, 1845, is so nearly related to
N. mixtum, Kr., that it may, perhaps, be only a variety
of that species, andin that case, of course, of N.
grossipes, 0. Fabr. ; however Wilson (Pycnogonida
of New England, Trans. Connect. Acad., vol. v.
p. 19, 1880) believes it a good spciues, readily dis-
tinguished by its extremely attenuated appearance.
From the Barents Sea I got some specimens, which
unquestionably belong to the form described by
Kroyer.
*Nymphon grossipes, 0th. Fabr. (sp.), 1780. Pijcno-
gonum grossipes, 0th. Fabr., Fauna Groenlandica, p.
229, 1780. (?) Phalangium grossipes, Linn., Syst.
Natura, xii. 1027, 1766 (?). (?) Nymphon grossipes,
Fabr., Entom. System, emendata et aucta, tom. iv.
p. 417, 1794 (?). N. grossipes, 0th. Fabr., Kroyer,
Bidrag till Kundskab, Nat. Tidskr., N. R., i. 108,
1845. N. grossipes, 0th. Fabr., Wilson, Pycnogon.
of New England, Trans. Connect. Acad., v. 21, 1880.
The species is best known from the descriptions
of Kroyer and Wilson. Three specimens were ob-
tained during the Challenger Expedition, and a single

Kerguelen.

Off Coast of Chili (Station 298,
Challenger Expedition).

British Seas everywhere (Leach),
Dutch Coast (Texel) (Hoek).

Lat. 63° 10' 2" N., long. 4° 59'
6"E. Lat. 64° 36' N., long.
10° 21' 5" E.

Between Celebes and Haluia-
hera.

Coast of Greenland and West
Norway ; off Halifax, St
George's Banks, lat. 61° 47'
2" N., long. 3° 18' 5" E.
Barents Sea (Hoek in MS.).

North Sea (Bohm, Pycnogoniden
des Museums zu Berlin,
Monatsber. der K. Akad,
d. Wiss. zu Berlin, 1879);
Coast of Norway (Kroyer),
Barents Sea (Hoek in MS.),
Northern part of the North
Atlantic ("Knight Errant,"
1880) ; East Coast of Green-
land (Fabricius, Buchholz) ;
North Georgian Islands
(Sabine, Suppl. to the Ap-

REPOKT ON THE PYCNOGONIDA.

21

Depth in Fathoms.

417 (Sars).

Name.

one during the cruise of the " Knight Errant " north
of Scotland.

Geographical Distribution.

(?)

lGO(Hoekin
MS).

146 to 180

(G. 0. Sars).

160(Hoekin

MS.).

(1) 25 to 35

(t) Nijynphnn mixfum, Kr., Nat. Tid.-kr. N. E., i. p. 100.
1845. N. mixfum, Kr., Buchholz, Zweite Deutsche
Nordpolarfahrt, Crust., p. 397, 1874. N. mixtiim, Kr.,
G. O. Sars, Prodromus (Archiv. f. Math, og Natur-
vid., ii. 366, 1877) = iV. grossipcs, 0. Fahr., Wilson,
Pycnogonida of New England, Trans. Connect. Acad.,
voL V. p. 20, 1880. Wilson thinks the N. miffnm,
Kr., is undoubtedly a form of N. gross! pes, 0. Fabr. I
also believe it so nearly related to N. grossvpes, that it
may be only a variety. Buchholz writes (loc. cif., p.
397) : — "Doch muss ich es dahingestellt sein lassen, ob
die von Kroyer angegcbene auf dein Verhiiltniss der
Liinge des Tarsus zum Endglied beruhende Artunters-
cheidung ausreichend ist, um diese Art von der vorigen
(N. grossipes, 0. Fabr.) zu trennen."
(1) Nijmphon hrevitarse, Kr., Nat. Tidskr. N. E., i. 115,
1845. N. hirsutum, Kr., Gronlands Amfipoder, p. 92,
1838 (Autoritate, Kroyer) = iV. grossipes, 0. Fabr.,
Wilson, Pycnogonida of Now England, Trans. Connect.
Acad., p. V. 20, 1880. In all probability Wilson is
right when he says N. hrevitarse is only a form of N.
gross ipiRS.
Nijmplwn sluiterii, Hoek, in MS., Pycnogonids of the
first two cruises of the W. Barents. A well-character-
ised arctic species, with extremely small auxiliary
claws, second joint of the palpus longer than third,
first tarsal joint longer than second, with a claw
at the end of the legs, which is not .shorter than
the last joint of the leg, and a truncate oculiferous
tubercle.
Nijmphon serratum G. 0. Sars, Crustacea et Pycnogonida
nova, Arch. f. jNIath. og Naturvid., iv., 471, 1879. An
extremely characteristic species, with a large spiue
dorsally on the first three segments of the trunk.
{VjNijrnphon brevirosfris, Hodge, Mennell, Eeport on Dredg-
ing off the Northumberland Coast and Doggerbank,
British Association Eeport, p. 119, 1862. A very
unsatisfactorily described species ; in all probability
the same as N. hrevitarse, Kr. = N. grossipes
0. Fabr.

pendix, &c., p. ccxxv. 1824);
Coast of North America, from
the Gulf of St Lawrence, as
far south as Long Island
Sound (W^ilson), Challenger
Exped., Station 49, South of
Halifax, U. S. A.
Coast of West Norway (Kroyer),
lat. 63° 10' 2" W., long. 4°
59' 6" E. (Sars) ; East Coast
of Greenland, Spitzbergen
(Buchholz, loc cif.).

Coast of Greenland.

Barents Sea (Hoek in MS.).

South of Spitzbergen, Barents
Sea (Hoek in MS.).

(?) Northumberland Coast, Dog-
gerbank.

22

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

(?)

(?)

0)
0)

(0
(0

Name.

Channel

(i) Ni/mpJwn (jJaciale, Lilljeb., N. glaciate, Lilljeb., White Sea.
Jarzynsky, Prremissus Catalogus Pycnogonidarum in
mari glaciali, Annales de la Soci6te des Naturalistes de
St Petersbourg, 1870. I have never seen a specimen
of it, nor do I know where the description of Lilljeborg
is to be found.

.?) Nymphon feriioratum, Leach, Zool. Misc., i. 45, pi. xix.
fig. 2, 1814. N. femoratum, Leach, Milne-Edwards,
Hist. Nat. des Crustacfe, iii. 534, 1840. N. femor-
atum, Leach, Johnston, An Attempt kc, Mag. of
Zool. and Botany, i., 1837. In all probability not a
good species : description very insufficient ; dilated
thighs are common to the females of almost all the
species.

(?) Nijmiihon pellucidum, Goodsir, Edin. New Phil. Journ.,
vol. xsxii., 1842. Characterised very insufficiently :
may turn out to be a variety of N. hrevitarse, Kr.

(?) Nymplwn spinosum, Goodsir, Ediu. New Phil. Journal,
vol. xxxii., 1842. Like the other .species of Goodsir,
N. spinosum has been described so very insufficiently
that it is not to be recognised.

(?) Nijmplion johnsfanii, Goodsir, Edin. New PhiL Journal,
vol. xxxii., 1842. A very uncertain species.

"?) Nymphon minutum, Goodsir, Edin. New Phil. Journal,
vol. xxxii., 1842. Goodsir's description is so insuffi-
cient that the species i^ not to be recognised.

(.?) Nymphon longireps, Grube, 46ster Jahres-Ber. der
Schles. Gesellsch. f. vaterl. Cult. p. 54, 1 869. The
description of this species is .so insufficient that it is
impossible to recognise it.

B. Species without auxiliary claws.

Geograjiliical Distribution.

Coast of England.
Coast of England.

Coast of England.
Coast of England.

China Sea.

480 (Station
56, "Por-
cupine"),
412 : 299

(Sars).
375, 540
(" Knight
Errant").
120 to IGO
(Barents Sea,
HoekinMS.).

'Nymplion rohiwtum. Bell, Belcher's Last of the Arctic
Voyages, vol. ii. p. 409, 1855, Tab. xxxv. fig. 4: = N.
hium, Heller, Crust, Pycnog. und Tunicaten der K. K.
Oester. Ungar. NordpoL Exped., Denkschr, d. Wiener
Akad. xxxv. p. 41, 1875, = iV. ahyssorum, Norm.,
Wyville Thomson, Depths of the Sea, p. 129, 1873. I
quite agree with G. 0. Sars (Prodromus, Arch, for Math,
og Naturvid., ii. 365, 1877), who places N. hiuns.
Heller, and N. ahyssorum, Norman, as identical with
this species. A large and excellent species abounding
in the higher northern latitudes. The largest haul of
Pycnogonids, Mr ]\Iurray writes to me, he ever saw
was that in which he got an immense number of speci-
mens of this species (Cruise of the " Knight Errant"
to the north of Scotland, Aug. 1880).

60" 2', 62° 44' 5", 64° 36' N.
lat. ; 6°11,' 1° 26' W. long.,
1° 48' E. long. Barents Sea
(Hoek in MS.). North of
Scotland.

REPORT ON THE PYCNOGONIDA.

23

Depth iu Fathoms.

Name.

Geographical Distribution.

1100

*NympTion eompactum, n. sp. A weU-characterised deep-

East of Auckland (Station 128,

sea species, of whicli only females — two specimens in

Challenger Expedition).

all — have been dredged.

50

Nijnqilmi 2)hasmatodes, Bolim, Pycnogoniden des Museums
zu Berlin, Monatsb. der K. Akad. der Wiss. zu Berlin,
p. 173, 1879,Taf.Lfig. 2-2h. Seems to be a good species.

Cape of Good Hope.

1375 to 1600

*Nymphon hamatum, n. sp. A good and common deep-

Between Kerguelen and Cape of

sea species.

Good Hope.

1100

*Nijm]jhon hmgicoxa, n. sp. A fine well-characterised

East of Auckland (Station 168,

deep-sea species, of which thirteen specimens were

Challenger Expedition).

dredged by the Challenger.

2160

*Nijmphon procerum, n. sp. A slender deep-sea species.

West ofValparaiso(Station299,

which is well-characterised yet requires further study.

Challenger Expedition).

Family II. CoLOSSENDEiDyE
Contains those Pycnogonida which have either rudimentary mandibles or no mandibles
at all, strongly-developed palpi and ovigerous legs present in both sexes, and as a rule
furnished with denticulate spines. The genera belonging to this group are very numerous :
Ammothea, Ascorhynchus, Achelia, and Colossendeis are typical representatives.

Depth in Fathoms.

Name.

Geographical Distribution.

(^)

0 to5

(?)

South Carolina.

Saint Malo (Coast of France).

Ammothea, Leach (1815).

Mandibles biarticulate, cheliform, feeble ; palpi nine-jointed; ovigerous legs ten-jointed

proboscis pyriform.

Ammothea carolinensis, Leach, Zool. Misc., voL i. p. 34,

1815, pi. xiii. Of this species a very good drawing

has been published by Leach.
Avwiothea pycnogonoides, Quatrefages, Memoire sur

I'organisation des Pycnogonides, Ann. d. Sc. Nat.

3ieme g^j.je, Zool., torn, iv., Paris, 1845. I think

this species is closely related to A. lonrjipes, Hodge,

but the descriptions of both authors are so very in-
sufficient that this is not to be made out.
Ammothea longipes, Hodge, Amu and Mag., 3d series,

vol. xiu. p. 114, 1864; Grube, Verhandl. d. Schles.

Gesellsch. f. vat. Ciiltur., 1869-72. The description

of this species is also quite insufficient; it cannot

be made out whether the species described by Grube is

identical with that of Hodge. The specimen of Grube

is furnished with six-jointed palpi, whence I believe it

not to have been an adult animal. In all probahUity it

is the same as that described by Quatrefages as A. pycno-
gonoides, Ann. d. Sc. Nat., iii. serie, Zool., torn., iv., 1 845.

Polperro (English Coast) (St
Vaast la Hougue (Grube):
Eoscoli' (Grube).

2-1

THE VOYAGE OF H.M.S. CHALLENGER.

Deiith in Fathoms.

(?) (Deep-
water).

(?)

(?)

0)

(?)
(?)

(?)

Name.

Geographical Distribution.

Durham Coast ; Heligoland
(Semper).

Bay of Fundy (U S. A.).

Ammothea hrevipes, Hodge, List of the Briti-sh Pycno-

gonoidea, with descriptions of several new species,

Ann. and Mag. of Nat. Hist., 3d series, xiii. 113, 1864.

Very insufficiently described.
Ammothea wheJioides, Wilson, Transact. Connect. Acad.,

vol. V. part 1, p. 16, 1880. "In general appearance it is

closely similar to Achelia spinosa, Stimpson" (Wilson,

loc. cit.). No doubt there is a near relation between

the genera Achelia and Ammothea, yet a minute

examination of "adult" specimens of both genera

makes it necessary to consider these genera pro-
visionally as distinct.

Bohmia, Hoek (1880).

Mandibles two-jointed, cheliform ; palpi seven-jointed ; ovigerous leg.s ten-jointed ;
proboscis conical, entirely bent over to the ventral side.

Bohmia cheJata, Bohm, sp. ; Pycnogonum chelatum, Bohm. (1)
Pycnogoniden des Museums zu Berlin, Monatsb. der
K. Akad. der Wiss. zu Berlin, 1879, p. 192 (pi. ii.
fig. 5-5'?). As the specimen observed by Bohm is
furnished with ten-jointed ovigerous legs, I think there
is not a single reason to consider it as a P[/cno(jonum
in the larval condition. I therefore propose to form a
new genus for it, and to call it after Mr Bohm.

Phanodemus, Costa (1836).
Mandibles cheliform ; palpi three- or four-jointed ; ovigerous legs (?) ; proboscis conical.

Phanodemus horridus, Costa, Fauna del regno di Napoli,
Crostacei et Aracnidi, Napoli, 1838, p. 8. Descrip-
tion of this species extremely insufficient.

Phanodemus collaris, Costa, Fauna del regno di Napoli,
Crostacei et Aracnidi, Napoli, 1838, p. 8. Also
described insufficiently.

Phanodemus inermis, Costa, Fauna del regno di Napoli,
Crostacei et Aracnidi, Napoli, 1838, p. 9. Descrip-
tion not better than those of the foregoing species.

Gulf of Taranto.

Gulf of

Naples.

Gulf of
Naples.

Taranto, Gulf of

Taranto, Gulf of

Rhynchothorax, Costa (1861).

Mandibles cheliform, four-jointed ; palpi eight-jointed ; ovigerous legs (?)

proboscis long-ovate.

(?) Rhynchothorax mediterranews, Cos., Microdoride mediter-
ranea, Napoli, 1861, p. 8, Taf. i. fig. 102. A very
curious animal, with a short and narrow abdomen of
seven joints. The description, however, is uiisufficient.

North Coast of Africa.

REPORT ON THE PYCNOGONIDA.

25

Depth in Fathoms,

(?)

Name.

Geographical Distributiou.

Pephre.do, Goodsir (1842).

Mandibles cheliform ; palpi three-jointed ; ovigerous legs six-jointed ; proboscis

short, cylindrical.

Q)

(?)

{1) Oiceohathes arachne, Hesse, Ann. d. Sc. Natur., Same
s^rie, vii. 201, 1867. Description quite insufficient.
Perhaps the genus Oiceohathes is the same as Ammothea.

1081 to 1539.

1375

(?)

38
130

Pephredo hirmta, Goodsir, Edin. New PhiL Journal,
1842, vol. xxxii. p. 136. The description of this
species as given by Goodsir is very insufficient.

Coast of England.

Platychelus, Costa (1861).
Mandibles cheliform ; palpi five-jointed ; ovigerous legs (?) ; proboscis pyriform.
Platychelus sardonicus, Costa, Microdoride mediterranea. Coast of Sardinia.
Napoli, 1861, p. 11. The description of the genus and
species is given from a single specimen, and this has
been most probably an immature female.

Oiceohathes, Hesse (1867).
Mandibles small, three-jointed, cheliform ; palpi eight-jointed ; ovigerous legs (t) ;

proboscis conical.

Coast of France (Brest).

Ascorhijnchm, G. 0. Sars (1877).

Mandibles rudimentary, cheliform or not cheliform ; proboscis pyriform, more or less bent

over to the ventral side ; palpi ten-jointed ; ovigerous legs ten-jointed

Ascorhynchm abyssi, G. 0. Sars, Arch. f. Math, og

Naturvid., ii. 367, 1877. This well-characterised

species is (according to Sars) very common in the great

depths of the cold region.
*Aseorhynehus glaher, n. sp. A beautiful and large

Ascorhynchus : not very different from A. ahyssi. G.

O. Sars, Arch. f. Math, og Naturvid., ii. 367, 1877.
Ascorhyncluis ramijtes, Bohm (sp.). Gnamptorhynchus

ramipes, BiJhm, Sitzber. der Ges. Naturf. Freunde zu

Berlin, 1879, p. 56. Ibid., p. 140.
*Asc<trhynch iis iiiinutics, n. sp. A well-characterised species,

nearly allied to A. randpes, Bohm.
* Ascorhynchiis orthorhynchus, n. sp. A very fine and,

I believe, weU-characterised species.

Atlantic between Iceland and
Norway. Lat. 63° 7' N.,
long, r 26' W. ; lat. 68°
13' 5"N., long. 0' 33' E.

Between Cape of Good Hope
and Kerguelen.

Enosima (.Japan).

Southern Coast of Australia :
off entrance to Port Pliilip.

Great Ocean, North of .:\.dniir-
alty Islands.

Zetes, Kroyer (1845).

Mandibles rudimentary, three-jointed ; palpi ten-jointed ; ovigerous legs nine- (noune

ten- (1) ) jointed ; proboscis long-ovate.

(1) Zetes hispidm, Kroyer, Naturhist. Tidskr. Ny Eaekke, i.

117, 1845. Zetes hispidus, Kroyer, Jarzynsky, Pra?mis-
sus Catalogus, Annales de la Soc. des Natur. de St
Petersbourg, 1870.

(ZOOL. CHALL. EXP. — PAKT X. — 1881)

Coast of Greenland, Coast of
Russian-Lapland.

Kl

26

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

(i)

(?)

0)

(?)

Low water
mark to 17
fathoms; 35
fathoms.

Low tide to
a few faths.
(Hodge).

Name.

Geographical Distribution.

Off Cape Sima (Japan).

Pamzetes, Slater (1879).

Mandibles rudimentary, two-jointed ; palpi nine-jointed ; ovigerous legs ten-jointed ;

proboscis fusiform.

Pamzetes aucJienicus, Slater, Annals and Mag. of Nat.
Hist., 5th series, iii. 281, 1879. Slater calls the generic
characteristic of Pamzetes " distinct." The description
of the genus and species has been given from a single
specimen, so I doubt whether the generic differences from
Zetes or any other closely-allied genus will hold good.

Panboea, Philippi (1843).

Mandibles rudimentary, two-jointed ; palpi five-jointed ; ovigerous legs nine
(noune ten- (?) ) jointed ; proboscis ovate.

Parihoea sjnm'pnipis, Philippi, Arch. f. Naturg., 1843, ix.
p. 178. Perhaps the description of this species is not
taken from an adult specimen.

Sorrento (Gulf of Naples).

Aldnovs, Costa (1861).

Mandibles rudimentary, three-jointed ; palpi seven- or nine-jointed ; ovigerous legs
eight-jointed ; proboscis long-ovate.

Aldnoiis vulgaris, Costa, Microdoride mediterranea, Mediterranean.

Napoli, 1861, p. 13. This species has, I believe, a

certain resemblance to an Ascorhijnchus.
Alcijunis mer/acejjJialus, Costa, Microd. medit. Napoli, Gulf of Naples.

1861, p. 14. This species belongs rather to Panboea,

Pliilippi, than to Alchwiis, Costa.

Achelia, Hodge (1864).

Mandibles rudimentary, two-jointed ; palpi eight-jointed ; ovigerous legs
ten-jointed ; proboscis pyriform.

Achelia spinosa, Stimpson (sp.). Zetes spinosa, Stimp-

son. Invertebrata of Grand Manan, 1853, p. 37. A.

spinosa, "Wilson, Pycnogon. of New England, Trans.

Connect. Acad, of Arts and Sciences, vol. v. p. 7, 1880.

The differences of A. spinosa, Stimpson, from Hodge's

A. echinata " seem scarcely sufficient to separate them

as distinct species" (Wilson, loc. cit.).
Achelia echinata, Hodge, British Pycnogonoidea, Ann. and

Mag. of Nat. Hist., 3d ser., vol. xiii p. 115, 1864. A

good description of this species has been given by Grube,

St Vaast la Hougue und seine Meercs — besonders seine

Anneliden-Fauna, Verhandl. d. Schles. Gesellsch. f.

vaterl. Cultur, 1869-72, p. 27 (Separatabdruck). Per-
haps identical with A. spinosa, Stimpson, Inverte-
brata of Grand Manan, 1853, p. 37.

Grand Manan ; Eastport, Casco
Bay, off Block Island, &c.

Channel Islands, Isle of Man ;
Durham Coast, St Vaast la
Hougue, Dutch Coast.

REPORT ON THE PYCNOGONIDA.

27

Depth in Fathoms.

(^)

0)

5 to 7

Down to 14
fathoms
(Wilson).

3 to 4 fathoms

(i)

700

Name.

Geographical Distribution.

Polperro, Cornwall (Hodge),
Nizza (Grube), Kerguelen
(Bohm).

Polperro, Cornwall.

Kerguelen Island, Observatory
Bay.

Achelia Iwvis, Hodge, British Pycnogonoidea, Ann. and

Mag. of Nat. Hist., 3d ser., vol. xiiL p. 115, 1864.

Bohm (Monatsb. d. K. Akad. der. Wiss. inBerl., 1879,

p. 186) refers to the same species a specimen from Ker-
guelen with seven-jointed palpi.
Achflia hispida, Hodge, British Pycnogonoidea, Ann.

and Mag. of Nat. Hist, 3d ser., vol. xiii. p. 115, 1864.

I doubt, whether this species described by Hodge is

indeed a true species.

TanysUjlum, Miers (1879).

Mandibles rudimentary, one-jointed ; palpi six-jointed ; ovigerous legs ten-jointed ;

proboscis rounded-conical.

Tany-stijlum sti/ligernm, Miers, Crustacea of Kerguelen

Island, Phil. Trans. London, voL cLxviii., extra vol., pp.

200-214, pL xi., 1879. Nymphvn stijligerum, Miers

(sp.), Ann. and Mag. of Nat. Hist., 4th ser., vol. xvi.,

1875. Most probably this is a good species ; however,

I do not feel quite .sure that the two specimens studied

by Miers are really full-grown animals.
Tanysfylum orhiailare, AVilson, Pycnogonida of New

England, Trans. Connect. Acad., vol. v. p. 5, 1880.

Whether or not Tanystylum will prove a well-char-
acterised genus, or will turn out to be identical with

Achelia, Hodge, is doubtful as yet.

Lecythcn-hynchus, Btihm (1879).
Mandibles rudimentary, two-jointed or represented by small knobs ; palpi nine-jointed ;
ovigerous legs ten-jointed ; proboscis cylindrical.
LecythorhyHchus Mlgendorfi, Btihm, Monatsb. der K. Enosima (Japan)

Akad. d. Wiss. Berlin, 1879, p. 187. Corniger liil-

gendorfi, Bohm (sp.), iUd. and Sitzungsber. d. Ges.

Naturf. Freunde zu Berhn, 1879, p. 140. Bohm has

given a good description of this species, loc. cit.
Lecythorhynchns armatus, Eiihrn, Sitzungsber. der Ges.

Naturf. Freunde zu Berlin, 1879, p. 140. L. Jdlgm-

dorfi, Biihm, is furnished wth rudimentary mandibles

represented by small knobs ; L. annatiis, Bohm, with

rudimentary but two-jointed mandibles. There can be

no doubt, however (according to Bohm), that these

species belong to the same genus.

Oorhynclius, Hoek (1880).
Mandibles rudimentary, one-jointed; palpi nine-jointed ; ovigerous legs ten-jointed ;

proboscis broadly ovate.

Vineyard Sound, and occurs as
far south as Virginia (Wilson,
loc. cit.).

Yeddo (Japan).

^■Oorhynchus ancldaudiw, n. sp. Of this very character-
istic Pycnogonid, only a single specimen was dredged
during the voyage of H.M.S. Challenger.

East of Auckland.

28

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

Name.

Geographical Distribution.

120 to 2.50
(Jarzynsky).
110 to 166

;Hoek in MS.).

540 ("Knight
Errant").

55 to 120

417

400; 1375;
1600

1800

1375 to 1600
25

120
1375 to 1600

Golossendeis, Jarzynsky (1870).

No mandibles ; palpi ten-jointed ; ovigerous legs ten-jointed ; proboscis long, cylindrical,

club-shaped or bottle-shaped.

2225

* Colossendeis iwohosdilea, Sabine (sp.). Phoxkhihis jjro-

boscideus, Sabine, Supplement to the Appendix of Cap-
tain Parry's Voyage, Zoology, p. ccxxvL C. horecdis,
Jarzyn.sky, Praemissus catalogus Pycnogonidarum inven-
tarum in mari glaciali ad oras Lapponicae rossicie et in
marialbo, anno 1869et70, Annalesde laSoc. desNatur.
de St Petersb., 1870. C prohnscidea, Sabine, G. 0.
Sars. Prodromus descriptionis, &c., Arch. f. JNIath.
og Naturv., ii. 268, 1877. A gigantic Pycnogonid of
the higher northern latitudes.

* Colossendeis megalonyx, n. sp. A well-characterised

species. In some respects it resembles the C. 2'ro-
loscidea, Sabine, of the higher northern latitudes ; it
has, however, a much more slender body and longer legs.
Colossendeis angusta, G. O. Sars, Prodromus descriptionis,
&c.. Arch. f. Math, og Naturvid., ii. 268, 1877. This
species is the slender Colossendeis of higher nothern
latitudes.

* Colossendeis leptorhynclnis, n. sjj. This species seems to

be a very good one. It is easily recognized by its
extremely long and narrow proboscis, of an almost
cylindrical shape.

* Colossendeis {jigas-leptorhynchus. A single specimen of

this form was dredged at Station 158. It shows the
proboscis of C. gigas, whereas the palpi are those of C.
leptorhynchus. In other respects it resembles both
species.

* Colossendeis gigas, n. sp. This seems to be the largest,

not only of the species of the genus Colossendeis, but
of all the difTerent forms hitherto described.
Colossendeis kroyerii, Wood-Mason (sp.). Rhopalorhyn-
chus kroyerii, Wood-Mason. A small but very charac-
teristic species of the genus Colossendeis.

* Colossendeis robusta, n. sp. A beautiful species, easily

to be recognised by the form of its proboscis, &c.

* Colossendeis gracilis, n. sp. The species C. media,

C. brevipes, and C. gracilis, proposed by me, only
show very slight differences. In regard to C. gracilis,
I tliink it is a very interesting fact, that one of the
specimens is furnished with distinct mandibles.
*Colossendeis 7nedia, n. sp. Characterised by the long claws
of the legs, and by the peculiar shape of the last joints
of the paljn.

Coast of Eussian-Lapland,
North Atlantic. Lat. 62°
44' 5" N., long. 1° 48' E.
Barents Sea (Hoek in MS.),
North of Scotland (" Knight
Errant ").

Lat. 50° S. : Kerguelen ; be-
tween Patagonia and the
Falkland Islands.

North Atlantic; lat. 63° 10' 2"
N., long. 4° 59' 6" E.

Between Kerguelen and Cape
of Good Hope ; West of Val-
paraiso ; between Hanover
Isle and Patagonia.

South of Australia at the
fiftieth parallel.

Between Cape of Good Hope
and Kerguelen; between Juan
Fernandez and Valparaiso.

Andaman Islands (Port Blair).

Kerguelen.

Between Cape of Good Hope
and Kerguelen.

West of Valparaiso.

REPORT ON THE PYCNOGONIDA.

29

Depth in Fathoms.

Name.

Geographical Distribution.

2650

*Colossendeis brevipes, n. sp. In all probability nearly
allied to C. media, Hoek, and C. gracilis, Hoek.
Perhaps not a distinct species but only a variety.

East of Buenos Ayres.

1250

*Colossendeis minida, n. sp. A very slender and easily
recognised species.

South of Halifax.

PasitJioe, Goodsir (1842).

No mandibles ; palpi eight-jointed ; ovigerous legs nine- (nonne ten-) jointed.

(')

il,)Pasithoe vesiculosa, Goodsir, Edin. New Phil. Journal,
vol xxiii. 1842. Description and characterisation of
species and genus insufficient.

Coast of England.

Endeis, Philippi (1843).

No mandibles; palpi seven-jointed ; ovigerous legs nine- (nonne ten-) jointed.

(?)

Endeis didadijla, Philippi, Ueber die Neapolitanischen
Pycnogoniden, Arch. f. Naturgesch. ix., 176, 1843.
Body ovate, ovigerous legs present. 1 think this must
be considered as a true representative of the genus
Endeis, proposed by Philippi. Semper (Ueber Pycno-
goniden, Arb. Zool. Zoot. Inst, in Wiirzburg, i. 281,
1874) considers it as a species of Pasiihoe, Goodsir.
But this quistion cannot be settled without more
detailed descriptions of the forms in question.

Naples.

(?)

(1) Endeis gracilis, Philippi, Ueber die NeapoUt. Pycnog.,

Naples.

Arch. f. Naturg., ix. 176, 1843. This species has a

very slender body. No ovigerous legs are mentioned :

•

perhaps the eight-jointed palpi are in reality the ovige-

rous legs, and this is a species of Phoxichilus without

palpi.

Diseoaraclme, Hoek (1880).

No mandibles ; palpi five-jointed ; ovigerous legs ten-jointed.

Shore.

*Discoarachne, brevipes, n. sp. A very curious species
with a disciform body and short legs.

Near Cape Town.

Family III. Pallenid^.
Contains those Pycnogonida, which have strongly developed cheliform mandibles, and
either rudimentary palpi or no palpi at all. Ovigerous legs are present m both sexes,
and furnished with denticulate spines (Pallene), or present in both sexes and not
furnished with denticulate spines (some species of Phoxichilidium), or present only
in the males (other species of Phoxichilidium). Two genera: Pallene, Phoxichi-
lidium.

30

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

Shore.

0 to 3

(')

(^)

38 to 40
0)

38 to 120

(?)

0)

38

Name.

Geographical Distribution.

PiAllene, Johnston (1837).

Mandibles cheliform ; palpi wanting ; ovigerous legs ten-jointed, present in both .sexes. The
last four joints of the ovigerous legs often furnished with denticulate spines.

Pallene hrevirostris, Johnston, An Attempt to ascertain,
&c., Mag. of Zool. and Bot, vol. i. 1837. P.
hrevirostris, Johnston, Grube, Mittheilungen iiber St
Vaast la Hougue, &c., Verhandl. der Schl. Ges. f.
vaterl. Cultur., 1859. P. hrevirostris, Johnston, Hoek,
Ueher Pycnogoniden, Niederl. Arch. f. Zool., iii.,
1877. A well-characteri.sed species.

C!) Pallene empusa, "Wilson, Pycnogonida of New England,
Trans. Connect. Acad., vol. v. p. 9, 1880. This
species is so closely allied to P. hrevirostris, John-
ston, of the European coast, that it must be considered
either as the same, or as a variety of that species.

(1) Pallene chelifera, Claparede (sp.), Beobachtungen iiber
wirbellose Thiere, p. 103, 186.3. Claparede gives a very
insufficient description of this species, which he con-
siders as a Plwxichilidivm. I think it most probable,
that it is closely allied to P. hrevirostris, Johnston.
Pallene spinipes, Fabr. Ptjcnogoniim spinipes, Fabr.
(sp.). Fauna GronI, p. 232. Pallene spinipes, Fabr.,
Kroyer, Bidrag til Kundskab, Naturhist. Tidskr., Ny
Eaekke, i. 118, 1845. Pallene spinipjes, Fabr., Jar-
zynsky, Prsemissus Catalogus, Annales de la Soc. des
Natur. de St Petersb., 1870.
*Pallene Imvis, n. sp. A well characterised Pallene species.
Pallme chiragra, Milne-Edw., Histoire Natur. des
Crustacfe, torn. iii. p. 535, 1840. The description of
this species given by Milne-Edw., loe. cit., is insufficient.
Perhaps it is the same as the species for which T propose
the name P. australiensis.
*Pallene australiensis, n. sp. Perhaps it is this species,
which has been described by Milne-Edwards as P.
chiragra (Hist. Nat. des Crust., iii. 535, 1840).
Pallene gruhii, Hoek. I propose this name for the
species described by Grube (Jahresb. der Schles. Ges. f.
vaterl. Cultur., p. 54, 1869), and which Grube con-
sidered as a species of Phoxichilidivm.
Pallene longiceps, Bcihm, Sitzungsber. des Ges. naturf.
Freunde zu Berlin, p. 59, 1879. A very curious species
with rudimentary two-jointed palpi in the male sex.
*Pallene languida, n. sp. Nearly allied to P. longiceps,
Bohm (Sitzungsber. des. Ges. Naturf. Freunde in
Berlin, 1869).

Northern Europe (Coast of
England, France, of the
Netherlands).

Vineyard Sound, Ncank, Con-
necticut (U. S. A.).

French Coast.

Coast of South Greenland ;
White Coast of Eussian-
Lapland.

South Coast of Australia.
Australia (Jervis Bay).

South-east Coast of Australia.
China Sea.

JapaQ.

Melbourne (Australia).

REPORT ON THE PYCNOGONIDA.

31

Depth in Fathoms.

12

(?)

0)

191 to 459

Name.

Pallene intermedia,KT'6jeT, Bidrag til Kundskab, Naturli.
Tidskr., Ny Raekke, i. 119, 1845.

Pallene discoidea, Kroyer, Bidrag til Kundskab,
Naturhist. Tidskr., Ny Eaekke, i. 120, 1845. Pallene
discoidea, Kroyer, Jarzynsky, Praemissus Catalogus,
Aimales de la Soc. des Natur. de St Petersbourg,
1870.

Pallene hispida, Stimpson, Invertebrata of Grand Manan,
p. 37, 1853. PseurtajHillene hispida, Stimpson (sp.),
Wilson, Amer. Jour, of Sc. and Arts, vol. xv. p. 200,
1878, Trans. Connect. Acad., v. 10, 1880. Wilson
considers tbis species, wbicb is a true Pallene, as repre-
senting a new genus, wbicb be calls Pseudopallene.
But tbere is no difference in tbe number of the joints of
the ovigerous legs, and tbe presence or absence of auxi-
liary claws furnishes by no means a trustworthy ground
for division of the genus. "This species is very sunilar
to tbe last (P. discoidea, Kroyer) and a larger number
of specimens may show them to be identical " (Wilson,
ibid.).

Pallene lappa, Bohm, Pycnogoniden des Museums zu
Berlin, Monatsber. der K. Ak. der Wissensch. zu
Berlin, 182, 1879. I was long in doubt whether tbis
species was a true Pallene or a Phoxichilidium. I
have arrived at the conclusion that it is indeed a
Pallene, but a young one, with not quite developed
ovigerous legs.
I}) Pallene circidaris, (j:OQ(is\x,'EAm. New Phil. Journal, vol.
xx'xii. p. 136, 1842. Goodsir's description is insuffi-
cient. Perhaps tbis species is nearly allied to P.
discoidea, Kroyer, Bidrag til Kundskab, Naturbist.
Tidskr., Ny Eaekke., i. 120, 1845.

Pallene malleolata, G. 0. Sars, Crustacea et Pycnogonida
nova, Arch. f. Math. og. Naturvid., iv. 469, 1879.
Seems to be a .'species characteristic of tbe higher
northern latitudes.

Shore.

Geographical Distribution.

Coast of South Greenland.

Coast of South Greenland,
White Sea, Coast of Eussian-
Lapland, and North Norway.

Near Eastport, Maine; off
Grand Manan.

Mozambique.

Scotland.

Lat. 72° 27' to 80° N., long. 5°
40' to 20° 51' E.

Phoxichilidium, Milne-Edwards (1840).

Basis of the proboscis dorsally covered by the front part of tbe cepbalotboracic segment.
On this front part the oculiferous tubercle is placed. Mandibles cbeliform ; palpi
wanting ; ovigerous legs five- to ten- (?) jointed, the last four joints never furnished
with denticulate spines ; in some species present in both sexes, in others only in tbe
male sex.

Phoxichilidium femorafum, Rathke (sp.). Nymphon
femoratum, Eatbke, Naturb. Selsk. Skr., v., i. 201,

Greenland, Russian - Lapland
(Jarzynsky), Norway, Den-

32

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

Name.

Geographical Distribution.

(')

Low water
mark (Wil-
son).

Tide-pools.

(^)

30 to 42
(Eohm).
7 to 20
(Challenger),

7 to 20

(?)
(Probably 25

to 35).

1799. Oriihyia coecinea, Johnston, An Attempt, &c..
Magazine of Zoology and Botany, voL i. p. 378,
1837. P. femoratum, Rathke, Kroyer, Bidrag til
Kundskab, Naturh. Tidskr. i., 1845; Hoek, Ueber
Pycnogoniden, Niederl. Arch. f. Zool., iii., 1877.
This is the largest of the Phoxicliilidmms oc-
curring in the neighbourliood of the shores of the
North Sea. (Ovigerous legs, occurring only in the
males, five-jointed).
(1) Phoxichilidhmi glohosum, Goodsir, Edin. New Philos.
Journ., xxxii., 1842. Description quite insufficient,
probably a female of some species or other.

Phoxirltiliilium maxillare, Stimpson, Invertebrata of
Grand Manan, 37, 1853. P. maxillare, Stimpson, Wil-
son, Pycnogonida of New England, Trans. Connect.
Acad., vol. V. p. 12, 1880. I never saw this species.
Wilson says it resembles P. femoratum of Europe.
It has five-jointed ovigerous legs, wanting in the
female.

Phoxkhilidium minor, Wilson, Pycnogonida of New
England, Trans. Connect. Acad., v. 13, 1880.
Smaller than P. maxillare, to which it is closely allied.
It has also five-jointed ovigerous legs, wanting in the
female. It may be a dwarf variety of P. maxillare
(Wilson).
(t) Pliox'cMlidiwn miitilatmn, Frey u. Leuckart, Beitrage zur
Kenntniss wirbelloser Thiere, p. 165, 1847. With the
fourth pair of legs rudimentary and one-jointed oviger-
ous legs. No doubt the descrijstion is taken from an
immature specimen.
* Phoxiddlidium fluminense, Krciyer, Bidrag til Kundskab,
Naturk Tidskr., N. R, L, 1845. Pallenefluminenais,
Kroyer (sp.), BiJlim, Pycnogoniden des Museums zu
Berlin, Monatsber. der KonigL Akad. der Wiss.,
p. 180, 1869. Dredged during the Challenger Ex-
pedition off Baliia, Ovigerous legs in both sexes,
ten-jointed.

Phoxicliilidium inmjne, n. sj). A very characteristic
species, vr\i\\ an extremely slender body armed with
spine-forming knobs.

PJwxiddlidium petiolatum, Kroyer, Bidrag til Kundskab,
Naturh. Tidskr., L, 1845. Pallene attenuata, Hodge,
Report British Association, 119, 1862. After Hodge
(Ann. and Mag. of Nat. Hist., vol xiii., 3d series, p.
116, 1864). PaUejie atte7iuata is a nynonym oi Krciyer's
P. petiolatum. Ovigerous legs seven-jointed, wanting
in the female.

mark, Heligoland, England,
Holland.

North Atlantic (Orkney).

Bay of Fundy, Casco Bay,
Halifax (East Coast of North
America).

Casco Bay (East Coast of North
America).

Heligoland.

Coast of Patagonia, Magellan
Strait, Coast of Brazil.

Bahia.

Coast of Norway (Oeresund),
Coast of Northumberland,
Doggerbauk.

REPORT ON THE PYCNOGONIDA.

33

Depth in Fathoms.

48 to 175

600

(?)

0)

Shore.

Tide-marks to
6 fathoms.

1675
1600 to 1950

1875

Name.

* Phoxichilidlum patagonieum, n. sp. A beautiful species.
It was dredged at different stations in the neighbour-
hood of the Patagonian coast.

*PhoxichiUdiu')n patagonieum, var. elegans, Hoek.
Whether this is a true variety of the preceding species,
or is only to be considered as a young specimen of this
species, I am unable to ascertain.
Plioxiehiiidium cligitatum, Bohm, Pycnogoniden des
Museums zu Berlin, Monatsber. der K. Akad. der Wiss.
in Berlin, 184, 1879. Perhaps nearly allied to my
P. patagimicum (ovigerous legs occurring only in the
males. Number of joints ?)
(I) Phoxichilidlum pygmceum, Hodge (sp.). Pallene
pygmcea, Hodge, British Pycnogonoidea, Ann. and
Mag. of Nat. Hist., 3d series, vol. xiii., 1864. As
far as I could ascertain from the extremely insuffi-
cient description of Hodge, and from his figures,
this species belongs to the genus Phoxichilidium.
One of the species of Phoxichilidium occurring on the
French and on the Dutch coast is probably the same
species. Should this prove to be true the ovi-
gerous leg is six-jointed and occurs only in the
male.
Phoxichilidium virescens, Hodge, British Pycnogonoidea,
Ann. and Mag. of Nat. Hist., 3d series, vol. xiii., 1864.
Description insufficient. As far as I could make out
it is one of the more common forms of the Dutch and
French coast. (Ovigerous legs wanting in the female,
six-jointed.)
Phoxichilidium lentitm, "Wilson (sp.). Anoplodactylus
lentils, Wilson, Pycnogonida of New England, Trans.
Connect. Acad, of Arts and Sc, vol. v. p. 14, 1880.
Wilson gives this name to the species described by
Smith (Report Invertebrata of Vineyard Sound, p. 250)
as Phoxichilidium maxillare. I think it is closely
allied to Phoxichilidium virescens, Hodge (Ann. and
Mag., 3d. ser., vol. xiii. p. 115, 1864). Ovigerous legs
only in the male, six-jointed.

* Phoxichilidium oscitans, n. sp. A very curious deep-sea

species, easily to be recognised.

* Phoxichilidium pilosum, n. sp. A beautiful deep-sea

species.

* Phoxichilidium mollissimum, n. sp. Unfortunately only
a defective specimen of this curious form was dredged
by the Challenger Expedition. It has ten-jointed
ovigerous legs.

(ZOOL. CHALL. EXP. — PART X. — 1881)

Geographical Distributiou.

Patagonia.

East of Cape Corrieutes (La
Plata).

Singapore.

En'dand.

English Coast (Polperro),
French Coast (Grube, Mit-
theilungen iiber St Malo u.
Eoscofl').

Vineyard Sound ; Bay of
Fundy (New England).

Atlantic : West of Azores.

Between Cape Town and Ker-
guelen ; between Kerguelen
and Melbourne.

Off Yeddo (Japan).

K 5

34

TITE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms,

(?)

(?)

(?)

Name.

Geographical Distribution.

Phoxichilidiiim jolinstonianum. While (sp. ). Nymplion South Seas.
joknstoiiianum, White, Proc. Zool. Soc. of London,
vol. XV., 1847. There can be no doubt that this species
belongs to Plwxich Hid turn : eyes situated above the
insertion of the chelicera (mandibles) ; beak (pro-
boscis) springing from the under side of the head ;
cliolicera with two basal joints, &c. The description,
however, is hardly sufficient. What White describes
as palpi are in all probability the ovigerous legs.
(1) Phoxichiliilium phusma, Wliite (sp). Nipniihoii phasma, South Seas.
White, Proc. Zool. Soc. of London, vol. xv., 1847.
Whether this species also belongs to this genus or is
to be considered as a Pallene (it is certainly not a
Nymphon) is not to be ascertained. White says it may
possibly be the other sex of the preceding

Oomerus, Hesse (1874).

Oculiferous tubercle plac id at the base of the proboscis ; mandibles with long pincers ;
palpi represented by small knobs ; ovigerous legs not present in the female.

(i) Oomerus st/'gmatopliorus, Hesse, Ann. d. Sc. Nat. Zool.,
Sitoe s^j.jg^ XX., 1874, art. 5, p. 18, pi. viii. In all
probability this is a species of the genus Phnxiduli-
dium, Milne-Edwards. Only a female without oviger-
ous legs, and with highly developed ovaries in the
fourth joint of the leg, was observed by Hesse.

Brest (Bretagne).

Family IV. Phoxichilid^.

Contains those Pycnogonida, which have neither mandibles nor palpi, or have them
rudimentary. Ovigerous legs, as a rule, only in the males, whereas Hannonia possesses
them in both sexes ; always without denticulate spines. Genera : Hannonia, Phoxicliilus,
Pycnogoniini.

Depth in Fathoms.

Name.

Geogi-aphical Distribution.

Hannonia, Hoek (1880).

Mandibles rudimentary, chelate, two-jointed ; no palpi

ovigerous legs ten-jointed.

present in both sexes.

Shore.

* Hannonia typim, n. sp. A short-legged species, a true
littoral form, with very characteristic features.

Cape of Good Hope.

REPORT ON THE PYCNOGONIDA.

35

Depth in Fathoms.

Shore.

m

Shore.

(?)

Tide marks to
430 fathoms.

Name.

Geographical Distribution.

Phoxkhilus, Latr. (1816).
Mandibles and palpi wanting ; ovigerous legs, seven-jointed, present only in the males ;

Plioxichilus

Coast of Norway ; Coast of
Russian-Lapland (Jarzynsky) ;
England (South Coast of
Devonshire).

Singapore.

French Coa.st
ranean C).

hody, as a rule, slender.

spinosiis, Montagu (sp.). Phalangium

ftpinosum, Montagu, Linu. Transact., vol. ix. p. 100,

pi. V. fig. 7, 1808. P. spinosus, Montagu, Johnston,

An Attempt, &c., Magaz. of Zool. and Bot, i. 1837.

Phoxkhilus spinosns, Mont., Kroyer, Bidrag til

Kundskab Natuih., Tidskr. Ny. Raekke, i., 1845.

The Plwxichilm spinosns, Leach, as described and

figured by Quatrefages (Ann. d. Sc. Nat. 3'*="« s6rie,

Zool., torn. iv. 184-5) is not a PhoxicMlus at all.

Perhaps it is a Pallene.
PhoxirJiilus meridionalis, Bohm, Pycnogoniden des

Museums zu Berlin, Monatsber. der Konigl. Akad. der

Wissensch. zu Berlin, 1879, s. 189, Taf. ii., fig. 4-46.

A species which stands between P. Iwvis, Grube, and

P. inermis, Hesse (Bohni).
(t) Phnxichiliis inermus, Hesse, Ann. d. Sc. Natur., 5'^™"=

serie, torn. vii. p. 199, 1867. Perhaps nearly allied to

P. kevis, Grube. Judging from Hesse's description, this

species is furnished with a three-jointed abdomen, and

this is not the case with Grube's species, nor perhaps

with any species of the Pycnogonida. It was taken

at Brest on the keel of a ship returning from the

Mediterranean.
Phoxichilus Imns, Grube, Mittheilungen liber St Malo

und Eoscoff, 1872. During a recent visit to Eoscoil'

(Bretagne) I collected specimens of this species, which

is easily distinguished from P. gpinosits, Montagu.
(I) Phoxichilus pigmams, Costa (Foxirhibis pignueus),

Fauna del Regno di Napoli, Napoli, 1836, p. 10.

This species, characterised by its smallness and by the

absence of the spines at the end of the joints of the

legs, is perhaps identical with P. inermis, Hesse, or

P. Iwvis, Grube. Description very insufficient. |

Pijcnogonum, Briinnich (1764).

Mandibles and palpi wanting ; ovigerous legs nine-jointed, present only in th

body, as a rule, robust.

*Pgcnngonum litorale, Strcim (sp.). Phalangium
litorale, Strom, Physisk. og ceconomisk beskrivelse
over fogderiet Sbndmor, Sorbe, 1762. P. litorale,
Strom, Kroyer, Bidrag til Kundskab, Naturh., Tidskr.
Ny Raekke, i. 126, 1845. P. litorale, 0. Fabr.,

or Mediter-

French Coast.

Gulf of Naples.

males

North European Coasts and
Seas ; Coast of Russian-Lap-
land (Jarzynsky) ; Coast of
North America, as far south as
Long Island Sound ; Coast ol

36

THE VOYAGE OF H.M.S. CHALLENGER.

Depth in Fathoms.

Name.

Geographical Distribution.

Wilson, Pycnogonida of Xew England, Transact. Con-

Chili (Gay) ; Mediterranean ;

nect. Acad., vol. V. p. 4, 1880. In the Ann. and Mag.

Japan. The greatest depth

of Nat. Hist, 5th series, vol. iii. p. 283, 1879, Slater

from which it' has been ob-

describes a variety of this species, which, being very

tained in Europe is, as far

slender, is named P. IHorale, var. tenue, Slater. It

as I could ascertain, 53

was dredged by Capt. St John and placed in the British

fathoms (" Knight Errant "),

Mus. Catal., 78, 11.

whereas it was dredged by
Smith and Harger (1872) at
a depth of 430 fathoms, east
of St. George's Bank, N. lat.
41° 25', long. 65° 42' 3" W.

(^)

(!) Pycnogonum australe, Grube, Jahresb. der Schles. Ges.
f. vaterl. Cultur, p. 54, 1869. Of this species only a
larva with three pairs of legs has been examined. It
seems to be a species with auxiliary claws at the ends of
the legs.

Australia.

Description of the Species Dredged DUPaNG the Challenger Expedition.

Nympho7i, Fabr.

N'l/mjyhon haiiuitum, n. sp. (PL L).

Diagnosis. — Body slender, body and legs almost entirely smooth ; eyes obsolete,
auxiliary claws wanting ; second joint of the palpi longer than the third ; second joint
of the leg longer than the fii-st and the thiixl ; second tarsal joint of the leg longer
than the first.

Desc7-i2>tion. — The body is slender, and the lateral processes are separated. The pro-
boscis is large, almost one-third the length of the body, slightly swollen in the middle,
and again at the extremity. The mouth is triangular, not very large. The cephalo-
thoracic segment (with the base of the mandibles swollen) is almost as long as the
proboscis. The eyes are obsolete, represented only by two small knobs behind the lateral
process of the cephalothoracic segment. The abdomen is rather large ; the mandibles
large, with the basal joint as long as the rostrum ; the claws of the chelse are elongated ;
the immovable claw more strongly curved than the movable one (PI. I. fig. 3). Both
claws are armed with spines ; on the movable claw they are more numerous and larger
(fig. 3). Seen but slightly magnified, the mandibles are smooth ; when greatly magnified
they show small hairs all over the surface.

The palpi are slender, longer than the rostrum ; the second joint is longer than the
third, the fifth longer than the fourth ; they increase in length as follows : — First,

REPORT ON THE PYCNOGONIDA. 37

fourth, fifth, third, second. The first and second joints are almost entirely smooth, the
third joint with small and the fourth and fifth with stronger hairs.

The ovigerous legs of the males are stronger than those of the females, and in all the
specimens are bent as shown in the figure (fig. 2). The fourth joint is curved, the fifth
thinner, and much longer than the fourth, and swollen at the extremity ; the sixth is
short, the seventh, eighth, ninth, and tenth very short ; the first joints are sparsely hairy,
the fifth not very hairy, the sixth hairy, with a row of stronger hairs at the outer extremity
of the joint. The spines of the four last joints are not very denticulated (figs. 4 and 5),
their numbers are respectively 12, 10, 9, 12 ; the end claw is denticulated also.

In the females the ovigerous legs are shorter, and not bent as in the males. The
fifth joint is only a little longer than the fourth, the sixth joint is less hairy, the
denticulated spines of the four last joints not so numerous, their numbers being
respectively 11, 7, 5, 7.

The legs are very long, measuring, for instance, 38 mm. in a female of 11 mm.,
and 44 mm. in a male of 13'5 mm. (1 : 3'4, and 1 : 3'3) ; the second joint, which is
swollen at the extremity in the females is longer than the first and third joints ;
the fifth joint is the longest, the sixth not much shorter ; the second tarsal joint is
longer than the first, the claw is not very strong, nearly half the length of the second
tarsal joint (fig. 9). Auxiliary claws are wanting. The fourth joint of the leg, which
in the females is swollen with the ovary, is furnished at the extremity with a
hook-like process bearing one or two hairs (fig. 8). I believe this is the first species of
Nymphon, in which this process has been observed, and therefore I have named the species
after it. This fourth segment is furnished in the males with a row of knobs, closed at the
extremity by a thin perforated membrane (fig. 7). Both males and females have the
legs almost entirely smooth, the hairs being so small as to be only visible under the
microscope. Larger hairs are seen at the extremity of the joints. The last joints are
furnished with small but very dense hairs. The genital openings of the females are
large, and easily observed on the lower side of the second joint on each leg (fig. (3).
Those of the males are a great deal smaller, and six in number ; they are not found
at the first pair of legs. The colour of alcoholic specimens is light yellowish (for the
larvas see below).

Habitat. — This very beautiful species was dredged during the Challenger Expedition
between the Cape of Good Hope and Kerguelen, oS" the Crozets Islands. There are in
all eight specimens, of which four are males and four females. One of the males was
furnished with eggs, or rather with young ones, adhering still to the accessory legs.
The species was found at two stations, at 1375 and 1600 fathoms. At the same time
were obtained two specimens of Ascorhynchus glaber, Hoek, two of Colossendeis gigas,
Hoek, three of Colossendeis leptorhyiichus, Hoek, three of Colossendeis gracilis, Hoek,
and one of Phoxichilidium pilosum, Hoek.

38 THE VOYAGE OF H.M.S. CHALLENGER.

Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E. ; Depth, 1375
fathoms. Bottom temperature, rs" C. Sea bottom, globigerina ooze.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. ; Depth, 1600
fathoms. Bottom temperature, 0*8° C. Sea bottom, globigerina ooze.

Observations. — Nymphon hamatum is a very fine deep-sea Pycnogoniu, and may easily
be distinguished from the other species. Among the described species of Nymphon it
shows some resemblance to Nymplhon macronyx, Sars, but this species is a great deal
smaller, has the mandibles and the legs shorter, shows a very prominent and curious-
shaped oculiferous tubercle,^ and has the claw of the leg as long as the second tarsal joint.

Nymphon longicoxa, n. sp. (PI. II. figs. 1-5 ; PL XV. figs. 8, 9).

Diagnosis. — Body very slender and smooth ; legs almost entirely smooth ; eyes
small but distinct, oculiferous tubercle rounded ; auxiliary claws wanting ; second joint
of the palpi very long, much longer than the third ; second joint of the feet much
longer than the first and the third, the sixth joint the longest, the second tarsal joint
longer than the first.

Description. — The body is very slender, the lateral processes with large intervals be-
tween them. The proboscis is large, one-third of the length of the body, in general resem-
bling that oi Nymphon hamatum, but a little narrower. The mouth is triangular, not very
large. The cephalothoracic segment is as in Nymphon hamatum. The eyes are rudimentary,
four, situated on a rounded tubercle. The abdomen is longer than in Nymphon hamatum.

The mandibles are very long, the basal joint longer than the rostrum, the second joint
also very long. The immovable claw, which is curved more strongly than the movable
one, is furnished with very large spines, which reach almost to the extremity (PL II. fig. 3).
The movable claw furnished with smaller spines has the extremity smooth ; the mandibles
are smooth, the second joint only furnished with microscopic hairs. The palj)i are
extremely slender, longer than the rostrum, the second joint is very large, the fourth
and fifth almost ecpal, the latter furnished with small hairs (fig. 2).

The ovigerous legs of the full-grown males are characteristic. The fifth joint is very
long, and describes an elegant curve ; it is divided into two parts by a rudimentary
articulation, and is strongly swollen at the extremity. The sixth joint, which is also
curved, makes an angle with the foregoing. The four last joints are small, and often bent
so as to describe a spiral. The first joints are smooth, at the end of the fifth there is,
on the outside, a small quantity of hairs, the sixth is furnished with numerous hairs, and
has on the upper surface rows of knobs of a curious shape. I have figured some of them
(PL XV. fig. 8). They are also present on the fifth joint, but are smaller and not so
numerous. The spines of the four last joints are much denticulated (PL II. fig. 4) ; their
numbers are respectively 13, 8, 7,6. The sj)ines of the end-claw are very small and blunt.

' See the description hereafter in the Appendix.

REPORT ON THE PYCNOGONIDA. 39

The ovigerous leg of the full-grown female is almost entirely straight. The difference
in length between the fourth and the fifth joints is not so considerable as in the males ;
the denticulated spines on the four last joints are more numerous than in the males,
their numbers being 19, 12, 10, 9. These curiously-shaped knobs do not occur on the
ovigerous leg of the female.

The legs are still longer than those of Nym'phon hanuitum. In a female of
12 mm. they measured 46 mm. ; in a male of 9^, 38 mm. (1 : 3-8 and 1 : 4). The
second joint is in the males four times as long as the first, in the females a little
shorter, but considerably swollen at the extremity ; the sixth joint is the longest, being
more than once and a half the length of the fifth ; the first tarsal joint is shorter than
the second, the claw is almost as long as the first tarsal joint, auxiliary claws are
wanting (PI. II. fig. 5). The first joints of the legs are almost entirely smooth, the
hairs increasing in number as they approach the extremity of the leg. The genital
openings of the females are very large, and are found on every leg. Those of the
males are smaller, and found only on the three hinder pairs of legs (PI. XV. fig. 9).
The colour of alcoholic specimens is light yellowish. (For the larvae see below.)

Habitat. — This fine species was dredged east of Auckland. There are in all twelve
specimens, of which only three are females. One of the males was furnished with larvae
clinging to the accessory legs. The depth at which the specimens were found is 1100
fathoms. At the same place two specimens oi Nymphon compactum, Hoek, were obtained.

Station 168. July 8, 1874. Lat. 40° 28' S., long. 177° 43' E. Depth, 1100
fathoms. Bottom temperature, 2"0°C. Sea bottom, grey ooze.

Observations. — I believe this species with its rudimentary eyes to form the transition
from the shallow-water species to the true deep-sea species. The very long coxae render
the species easily distinguishable.

Nymphon procerum, n. sp. (PL II. figs. 9-12).

Diagnosis. — Body extremely slender, smooth ; legs hairy ; eyes obsolete ; auxiliary
claws wanting ; the second joint of the palpi a little longer than the third, the second
joint of the leg longer than the first and the third, the second tarsal joint of the leg a
little longer than the first.

Description. — The body is very slender, and the lateral processes are separated by large
intervals. The proboscis is slender, shorter than one-third of the length of the body, in
the middle a little thicker. The cephalothoracic segment is longer than the proboscis.
Eyes are wanting ; the abdomen is small and bent upwards. The mandibles are very
long, the basal joint longer than the rostrum, the second joint also long and slender, the
claws very long ; the spines of the movable claw are smaller, and closer to one another
than are those of the immovable one (PI. II. fig. 10). The palpi are very slender, much
longer than the rostrum ; the second joint is a little longer than the third ; the fourth and

VVOODS

40 THE VOYAGE OF H.M.S. CHALLENGER.

fifth together are as long, or a little longer than the second joint. The palpi are nearly-
hairless, only the last joints being furnished with very small hairs. The ovigerous legs
are feeble, shorter than the length of the body, the fourth joint has a distinct knob at
a distance of nearly a third of its length, measured from the beginning ; the fifth joint is
the longest, the sixth half the length of the fifth, the seventh to the tenth armed with
sharply denticulated spines (PL II. fig. 12) ; the claw has numerous and dense spines
(PL II. fig. 11). The ovigerous legs are almost entirely smooth.

The legs are slender, being more than three times as long as the very long and slender
body (body 12 mm., legs 38 mm.). The second joint is longer than the first and third,
and is considerably swollen ; the fourth joint is swollen with the ovaries, and is nearly
as long as the fifth joint, the sixth joint is the longest. The two tarsal joints describe
a slight curve, the second is a little longer than the first, the claw is short, auxiliary claws
are w\anting. The fourth, fifth, and sixth joints have long but not very dense hairs. The
seventh and eighth joints have denser but very small hairs. The second joint of each
leg is furnished with a large genital opening.

Habitat. — The single female specimen of this species was dredged West of Valparaiso,
at a depth of 2160 fathoms.

Station 299. December 14, 1875. Lat. 33° 31' S., long. 74° 43' W. Depth, 2160
fathoms. Bottom temperature, 1"1° C. Sea bottom, grey mud.

Observations. — There can be Little doubt, I believe, that this species is closely aEied
to the two foregoing species. Yet I think its extremely slender and elongated form of
body characteristic enough to establish a new species upon it. With the exception
of Nijmphon longicollum, dredged from a depth of 2225 fathoms, of all the genus
Nymphon procerum inhabits the greatest depth.

Nymj^hon longicollum, n. sp. (PL III. figs. 1-3 ; PL XV. fig. 11).

Diagnosis. — Body slender; distance between the insertion of the rostrum and the
attachment of the ovigerous legs very great ; eyes obsolete, auxiliary claws extremely small.
The second joint of the palpi twice as long as the third, the second joint of the leg three
times as long as the first, the second tarsal joint of the leg nearly as long as the first.

Description. — The body is slender, the proboscis long, and exactly cylindrical ; the
cephalothoracic segment is much longer than one-third of the length of the body. The
intervals between the lateral processes of the body are very large, they are totaUy
wanting between the attachment of the ovigerous leg and of the first true leg.
Eyes are wanting, but the conical oculiferous tubercle is very large and acute. The
abdomen is small.

The mandibles have the basal joint as long as the rostrum, the second joint is
short, and furnished with short claws. The movable claw is a little longer than the
immovable one, the former is curved at the extremity, the latter straight. The spines

REPORT OX THE PYCXOGONIDA. 41

on tlae claws are not very prominent (PI. III. fig. 3). The two joints are sparsely
hairy, but the hairs of the second joint are longer than those of the first.

The palpi are not very long, and are feeble. The second joint is considerably longer
than the third ; the first and second together are nearly as long as the last three together.
The hairs are much more numerous on the outer joints than on the first two.

The ovigerous legs are not very long. The first four joints are almost entirely smooth,
with the exception of some long hairs at the extremity of the fourth joint ; the fifth and
sixth are hairy when seen through the microscope, the spines of the four last joints are
sharply denticulated, their numljers being respectively 9, 6, 5, 5. On the claw there are
five not very strong spines. The fifth joint of the ovigerous leg is the longest.

The legs are very slender. The length of the body of the single specimen is nearly
6 mm., that of the leg 26 mm. The second joint is three times as long as the third, the
fourth and fifth are nearly equal, the sixth united with the two tarsal joints are as long as
the fourth and fifth together. The first tarsal joint is at the first leg a great deal shorter
than that of the second. In the other legs the difference between the two tarsal joints is
not so considerable ; the claw is half as long as the second tarsal joint. The auxiliary
claws are extremely small (PI. XV. fig. 11). The legs, when examined with a magnifying
glass of small strength, are quite smooth ; when magnified greatly they show small hairs
which increase in number and size towards the extremity of the leg (?). The single
specimen of this species brought home by the Challenger is in all probability a male.
The animal is perhaps a young one, as I failed to observe the genital openings.

Habitat. — The specimen was dredged off the coast of Chili.

Station 298. November 17, 1875. Lat. 34° 7' S., long. 73' 56' AV. Depth, 2225
fathoms. Bottom temperature, r3° C. Sea bottom, grey mud.

Observations. — This curious species is very easily distinguished by its extremely long
neck and legs, the latter being more than four times as long as the body. From its long
slender neck it bears a certain resemblance to Nymi^hon longitarse, Kr. It is a true
deep-sea species.

Nymphon compactum, n. sp. (PI. II. figs. 6-8 ; PL XV. fig. 10).

Diagnosis. — Body stout, sparsely hairy ; eyes obsolete ; auxiliary claws wanting.
Second joint of the palpi longer than the third, the second jomt of the leg longer than the
first, the second tarsal joint shorter than the first.

Description. — The body is stout, the proboscis thick and swollen a little in the middle,
and again at the extremity ; the length about one-third of the length of the body. The
cephalothoracic segment is short, swollen anteriorly, and constricted in the middle. Eyes
are wanting, the oculiferous tubercle is represented by a blunt knob (fig. 7). The al^domen
is long. The intervals between the lateral processes of the body are small. The body is
almost smooth, and the lateral processes are furnished with long hairs. The mandibles

(ZOOL. CHALL. EXP. — PART X. 1881) K 6

42 THE VOYAGE OF H.M.S. CHALLENGEE.

are long, the first joint a little curved, and much longer than the proboscis ; at the
ventral side this joint shows feebly an articulation near the base ; the second is shorter,
but furnished with very long claws, which are curved at the extremity, and both are
armed with almost the same number of spines. The hairs on the mandiljles are distant,
the largest quantity being observed on the base of the immovable claw. The palpi are
not very slender, yet a great deal longer than the proboscis ; the second joint is the
longest, then follow the third, the fifth, the fourth, and the first, which is the shortest of
all. On the first two joints the hairs are not so numerous as on the last three joints.

The ovigerous legs of the female (the two specimens dredged by the Challenger were
both females) are tolerably long and stout, once and a third as long as the body ; the
fourth, fifth, and sixth joints are nearly of the same length, the fourth being the longest,
and the sixth the shortest. The four last joints again are of al^out the same length, the
claw is slender, its length two-thirds the length of the last joint. Joints one to four
are almost entirely smooth, with the exception of a row of hairs at the end of the fourth
joint ; joints five and six are furnished with numerous spines, the last four joints showing
hairs only at the distal extremity. The spines of the four last joints (figured on PL II.
fig. 8) are of a very irregular shape, and not very numerous, their numbers being re-
spectively 10, 8. 5, 7. The sjjines of the claw are not very strong.

The legs are three times as long as the body (36 mm. in a body of 12 mm.). The
second joint is longer than the first and third, and swollen, as is always the case in the
females. The fourth joint is also very considerably swollen (with the ovaries), the fifth
and the sixth joints are nearly of the same length, and a little longer than the fourth ;
of the two tarsal joints, which are together nearly two-thirds the length of the sixth joint,
the first is longer than the second (PI. XV. fig. 10). The claw is half the length of the
second tarsal joint, auxiliary claws are wanting. The fourth joint of the leg is sparsely
hairy, the fifth a little more so, the sixth is very haiiy and shows some strong spines at
the extremity, the two tarsal joints are covered with very minute hairs. The genital
openings are large and easily seen.

Habitat. — Of this species two females were di'edged along with Nymphon longi-
coxa, east of Auckland.

Station 168. July 8, 1874. Lat. 40° 28' S., long. 177° 43' E. Depth, 1100
fathoms. Bottom temperature, 2'0° C. Sea bottom, grey ooze.

Ohservations. — Nymphon lonrjicoxa and Nymphon compactum were obtained from
a depth of 1100 fathoms. Nymphon longicoxa .shows rudimentary eyes, those of
Nymphon compactum are quite obsolete. Nymphon longicoxa is one of the most slender,
Nymphon compactum one of the stoutest species dredged by the Challenger. In the one
the auxiliary claws are wanting, whereas small ones are present in Nymphon longicoxa,
and in every other respect they are as widely different as two species of the same genus of
Pycnogonids can be. Nymphon compactum shows some relationship to Nymphon strcemii.

REPORT ON THE PYCNOGONIDA. 43

Kr., but my species may be readily distinguished l)y its very short cephalic segment,
the absence of auxiliary claws, of eyes, &c.

Nymiolion meridionale, n. sp. (PL III. figs. 4-8).

Diagnosis. — Body slender and smooth, legs not very hairy, slender ; eyes four,
distinct; auxiliary claws present; second joint of the palpi longer than the third; second
joint of the legs elongated, second tarsal joint of the leg shorter than the first.

Description. — The ])ody of this species is slender, the lateral processes are widely
separated with the excej)tion of the lateral process of the first leg, and the small process
of the ovigerous leg. The proboscis is cylindiical, its length is almost one-third of the
length of the l3ody. The cephalothoracic segment with the base of the mandibles is
considerably swollen, very large, longer than the two following segments united. The
eyes are distinct, four, placed round a small conical tubercle. The abdomen is small.

The mandibles are very long and robust. The first joint is a little curved, and longer
than the rostrum, the second joint is also large, and furnished with very strong claws
(PI. III. fig. 5). The movable claw is longer and more deeply curved than the immovable
one ; both are furnished with a row of blunt and strong sjaines. The immovable claw
shows numerous hairs which are also oljserved at the base of the movable one. The palpi
are very long, the second joint is the longest, the third reaching farther than the rostrum,
the fourth and the fifth furnished with numerous hairs, and about the same length.

The ovigerous legs are comparatively small in the single specimen dredged Ijy
the Challenger, which I think is a male not yet fully grown. The fifth joint is the
longest ; the four last joints are furnished with very numerous denticulated spines,
their numbers being respectively 17, 16, 13, 13. These spines are comparatively small;
they are elongated, and densely denticulated (PL III. fig. 6). The claw is not very long,
and is furnished to the end with a row of short and blunt spines. AH the joints of the
ovigerous legs are smooth, with the exception of a few hairs placed at the extremity of
the fourth and tenth joints.

The legs are long and slender; the specimen of 6^ mm. shows legs of 21-^ mm.
The second joint is more than twice as long as the third ; the sixth joint is the
longest, the second tarsal joint is shorter than the first (PL III. fig. 7), the claw is vevj
small, the accessory claws are half as long as the claw (fig. 8) ; longer hairs are placed
at the extremity of every joint, shorter ones cover the outer joints all over, and are a
great deal less numerous on the inner joints. The genital openings I could not observe.

Habitat. — The only specimen was dredged in the Antarctic Ocean, at Station 153.
February 14, 1874. Lat. 65' 42' S., long. 79' 49' E. Depth of the sea, 1675 fathoms.
Sea bottom, mud.

Observations. — This is the most southern species of Nymphon (of Pycnogonids in
general) hitherto observed. I think this form is closely related to Ni/mpJion graciliiJes,

44 THE VOYAGE OF H.M.S. CHALLENGER.

from Kerguelen ; yet the two species may easily be distinguished from each other
by the form of the oculiferous tubercle, by the length of the claws of the mandiljles,
and by the length of the legs, which are in Nymplwn gracilijyes, Miers (after Bohm),
five times as long as the body. It is remarkable that this species living at a depth
of 1675 fathoms should have normally developed eyes.

Nymphon cjrossipes, 0th. Fabr. sp. (PI. III. figs. 9-12 ; PI. IV. fig. 1).^

Pijcnogonurii grompes, Oth. Fabr., Fauna Grcenlandica, p. 229, 1780.

Nymphon r/mssipes, Oth. Fabr., Kroycr, Bidrag til Kundskab, Naturh. Tidskr. N. E., vol. i.
p. 108, 1845.

Nymphon grossipes, Oth. Fabr., Wilson, Pycnogonida of Now England, Transactions Con-
necticut Acad., vol. V. p. 21, 1880.

Description. — The body of this species is slender and almost smooth, the lateral
processes are widely separated, with the exception of the small lateral processes of the
ovigerous legs, and those of the first pair of true legs, between which no interval is
observed. The proboscis is not very long, cylindrical, a little swollen at the extremity.
The ccplialothoracic segment is longer than the rostrum, swollen considerably at the base
of the mandibles. The abdomen is small. The oculiferous tubercle is very prominent,
conical, acute. The eyes are four, large (PI. IV. fig. 1).

The mandibles have a long basal joint, which is longer than the j^roboscis and narrower ;
the second joint is not very long ; the claws are short, not very hairy, but armed with
numerous equi-distant spines (PI. III. fig. 10). The two mandibles are, in the three
specimens procured, strongly divergent. The palpi are not very slender, nearly one-half
as long as the proboscis, with the second joint not quite as long as the third, and the fifth
longer than the fourth, furnished with numerous hairs at the end of the thii'd joint, on
the fourth, and on the fifth joint.

The ovigerous legs of the males (PI. III. fig. 9) are long, more than one-half longer
than the body, the fourth joint is the longest, the fifth nearly as long, all the joints are
covered with very small perpendicular hairs. The spines of the four last joints are small,
but numerous and elongated, sharply serrated (PL III. fig. 11). The claw is small, with
numerous thin spines.

The ovigerous legs of the female are much shorter ; 8 mm. in a female of 7 mm.
The relative length of the joints is the same as in the male. The hairs are much smaller.
The numbers of the denticulated spines on the four last joints are respectively 18, 17, 16,
14. There are about sixteen very slender and pointed spines at the claw.

The legs are long and slender, nearly five times as long as the body ; a male of 8 mm.
has legs of 38 mm. The joints are sparsely hairy, with a row of stronger hairs at the
junction of two joints ; the second joint is twice as long as the first ; the sixth joint
is by far the longest. The first tarsal joint is longer than the second, which is armed with

» The figures on Plate III. and IV. belonging to this species are marked, JV. annatum, n.

.SP.

REPORT ON THE PYCNOGONIDA. 45

a row of very strong hairs placed between the thinner ones (fig. 12). The auxiHary claws
are longer than half the length of the claw.

The one female specimen shows large genital openings on the second joint of every
leg ; the two males have the openings a great deal smaller, and only on the six hind legs.
The female is immature. Its length is 7 mm., that of the males 8 mm.

Habitat. — Of this species three specimens were dredged along with Nymjihon hrevi-
collum, south of Halifax.

Station 49. May 20, 1873. Lat. 43° 3' N., long. 63° 39' W. Depth, 83 fathoms.
Bottom temperature, 1-6° C. Sea bottom, gravel, stones.

Observations. — The specimens of this species have long been considered by me as
closely related to, yet distinct from the Nymplion grossipes, 0. Fabr. When I first
examined this species, and made the cbawings as figured on Plate III, I knew
Nymphon grossipes only by the description of Kroyer. Since that time Mr Wilson's
paper was published (March 1880), and as soon as I read his description of Nymphon
grossij)es, I almost felt sure that he had examined specimens c^uite identical with mine,
and had rightly considered them as Nymp)lwn grossipes. Lately I have had an oppor-
tunity of comparing the specimens of Nymp)hon grossipes dredged during the Challenger
cruise with others, undoubtedly belonging to the same species, collected during the two
cruises of the Dutch schooner " Willem Barents " in the Barents Sea. As there are,
however, a few differences to be pointed out, it would perhaps be better to consider the
Challenger specimens as forming a variety of this species, yet I hesitate to make such a
proposal, as it is impossible to settle these questions without large collections from the
same, or about the same, localities.

Nymphon brevicollum, n. sp. (PI. III. figs. 13-15, PL XV. figs. 12, 13).

Diagnosis.— 'Eodj not very slender; legs slender, smooth; neck short; a small
interval between the attachment of the ovigerous leg and the first true leg ; intervals
between the lateral processes short ; oculiferous tubercle blunt ; second joint of palpi
longer than third, second joint of the legs longer than first and thiixl, second tarsal
joint shorter than the first. Auxiliary claws present.

Description. — The pr(il)oscis of this species is comparatively large, and nearly
cylindrical. The neck is short, yet the segment formed by the conjunction of the
cephalic and the first thoracic segment is tolerably large, there being also an interval
(longer in the females than in the males) between the ovigerous leg and the first true leg.
The abdomen is small. The oculiferous tubercle rounded and small, with four brown eyes.

The mandibles vary considerably ; they often have the first joint shorter than the
rostrum, the second joint comparatively long, the claws long also, armed with numerous
small spines. Those of the males are more slender than those of the females.

The palpi are very slender ; the first and second joints forming in the females a right

46 THE VOYAGE OF H.M.S. CHALLENGER.

angle with the proboscis. The second joint is very long, much longer than the third.
The fourth and fifth are nearly ec^ual, shorter than the third joint, together nearly as long
as the second. The hairs on the first three joints are few, on the last two numerous,
closely adhering to the joints. The palpi of the males show the same length relatively
to the joints, but they are more parallel with the dii-ection of the proboscis.

The ovigerous legs are slender, only a little longer than the Ijody in the female. The
fourth and fifth joints are nearly of the same length, the sixth shorter. The four last joints
are strongly bent, and describe a spiral. The denticulated spines are long and slender,
their numbers being respectively 17, 14, 11, 13. The claw is very large, and furnished
with numerous small spines (PI. III. fig. 14). The first four joints are almost smooth,
the number of hairs increasing from the fifth to the tenth joint, specially large hairs
being placed at the end of the joints.

In the males the ovigerous legs are a great deal longer, nearly 11 mm. when the body
is 6 mm. ; the fourth joint is curved ; the fifth forms an angle with the fourth, is very
long, and shows a rudimentary articulation (PI. XV. figs. 12, 13) at two- thirds of the
length of the joint from the beginning ; the sixth joint is short, but swollen ; the four
last joints and claw as in the femnle, the denticulated spines being more numerous, and
respectively 19, 16, 12, 15.

The legs of the females are more than four times as long as the body (being 31 mm.
long when the body is 7 mm.). The second joint is considerably swollen, as is the
fourth, which contains the ovary ; the fifth joint is longer and thinner than the
fourth, and the sixth than the fifth. The first tarsal joint is longer than the second,
the auxiliary claws are two-thirds of the length of the claw. The fourth and fifth joints
are ahnost smooth, with the exception of some strong hairs on the fifth joint, and a row
of smaller spines at the extremity. On the sixth joint the number of hairs increases
towards the extremity ; the two last joints have a large number of rather strong hairs.

The leg of a male of 6 mm. is about 25 mm. The leg is a great deal more slender,
especially the second and fourth joints, but the relative length of the joints is the same.
The auxiliary claws of the males are a great deal shorter than those of the females, their
length never reaching half the length of the claw, and often being much shorter. The
genital openings of the females are much larger than those of the males. In the females
they are found on all the legs, in the males they are wanting on the first pair of legs.

Habitat. — With the foregoing species, south of Halifax.

Station 49. May 20, 1873. Lat. 43° 3' N., long. 63" 39' W. Depth, 83 fathoms.
Bottom temperature, 1"8° C. Sea bottom, gravel.

Ohscrvations. — Of this species eight specimens were dredged by the Challenger. Of
these five are females. Of the three males one is furnished with eggs. These specimens
agree perfectly as to the relative lengths of the joints of the palpi, and of the tarsal
joints of the legs, so that these characteristics are, for this species at least, really dis-

REPORT OX THE PYCNOGONIDA. 47

tinguishing features ; these marks, together with the structure of the first segment of
the body, of the ocuHferous tubercle, &c., make this species one of the most sharply-
characterised forms of the genus.

Nymphon hrachyrhynchus, n. sp. (PI. IV. figs. 2-7).

Diagnosis. — Body not very slender, smooth ; legs hairy. Proboscis short. ]\Ian-
dibles large. Second joint of palpi a little shorter than third. Second tarsal joint of
the leg longer than the first. Auxihary claws small.

Description. — The body of this species is not very slender ; yet there are distinct
(but small) intervals between the lateral processes of the body. The proboscis is short,
the segment formed by the conjunction of the cephalic and the first thoracic segment is
also short, as well as the following thoracic segments. The abdomen is comparatively large
and robust. The oculiferous tubercle is small and blunt, the eyes are four in number,
small, and not very distinct, light brown. The body is quite smooth. The length of the
female is nearly 7 mm., that of the male 6 '5 mm.

The mandibles are large. The first joint is almost as long as the proboscis, the second
joint curved and long, the claws long also. These claws are curved and furnished -^vith
numerous teeth ; they are more numerous and smaller on the immovable than on the
movable claw (PI. IV. fig. 4). The two claws when closed meet along their whole length,
the tips only crossing for a smaU extent.

The palpi (PI. IV. fig. 5) are very slender, more than twice as long as the proboscis.
The third joint is longer than the second, the fourth again longer than the third,
the fifth much more slender, but almost as long as the second. Hairs are scarce on the
second, not very numerous on the third joint, more numerous on the fourth, and very
numerous on the fifth joint.

The ovigerous legs of the males are more than 10 mm. long ; .the fourth joint slightly,
the fifth strongly curved and very long, the sixth joint short ; the four last joints are short
and wound up spii-aUy. Small hairs are placed vertically on the fifth and sixth joints,
larger ones at the extremity of the joints. The denticulated spines greatly resemble
those of Nymphon longicoxa, though they are a little flatter ; their numl^ers are respectively
13, 9, 7, 7. The spines of the claw are small and not very numerous (PL IV. fig. 6).

The ovigerous leg of the female is a great deal smaller : a female of 7 mm. in
length has ovigerous legs of 8 '5 mm. The fourth and the fifth joints especially are much
shorter, and the latter are quite straiglit. The denticulated spines of the four last joints
are more numerous than in the males; they are 14, 12, 10, 9, which numbers, however,
vary slightly for the difi'erent specimens. The claw with its spines is like that of the male.
The legs are slender, those of a male of 6-5 mm. nearly 25 mm., those of a female of
7 mm. nearly as long (25"5 mm.). The second joint is more than thrice as long as the thml,
the fourth and the fifth nearly of the same length, the sixth almost once and a half the

48 THE VOYAGE OF H.M.S. CHALLENGER.

length of the fifth. The two tarsal joints, of which the second is longest, describe a slight
curve ; the claw is large, the auxiliary claws are very small (PI. IV. fig. 7). Beginning
at the fourth joint the number of hairs regularly increases down to the end of the leg.

The legs of the females show the second and fourth joints considerably swollen. In
the females the genital jjores are large, and to be found on every leg ; in the males they
are much smaller, and occur only on the two hind pairs of legs.

Hahitat. — A large number of specimens of this species was gathered in Christmas
Harbour, Kerguelen. There are a great number of females with the ovaries swollen in
the fourth joint of the leg ; a great many males with and without eggs or larvae on their
ovigerous legs.

The specimens were dredged at a depth of 45 to 120 fathoms. (January 29, 1874.
Off Christmas Harbour. Depth, 120, 105, and 45 fathoms.)

Observations. — This fine species shows very characteristic marks, and cannot easily
be confounded with other species. In some respects it shows a resemblance to NymiJhon
strcemii of Kroyer.

NympJion fuscum, n. sp. (PL IV. figs. 8-11).

Diagnosis. — Body and legs very slender. Cephalic segment of the body large,
occasioned by the length of the so-called neck. Second joint of the palpi the longest ;
second joint of the leg three times as long as first ; tarsal joints of leg nearly equal.
Accessory claws present.

Description. — In this species the body is again extremely slender. The proboscis is
short, the mouth small. Of the cephalothoracic segment the so-called neck is long, the
segment itself is not very long, there being no interval between the ovigerous leg and
the first true leg. Between the true legs the intervals are, on the contrary, very great.
The abdomen is minute. The eyes are very large, covering almost the entire surface of
the short and blunt oculiferous tubercle.

Of the mandibles, the fixst joint is longer than the proboscis, the second is compara-
tively short, and so are the claws. The movable claw is a great deal more slender
than the immovable one, the latter is furnished with larger teeth, which are not so acute
as the smaller ones of the movable claw (PL IV. tig. 9).

Of the palpi the second joint is the largest, the fourth the shortest (PL IV. fig. 10).
The last joints are extremely hairy, but hairs are also to be found on the second and
third joints. The palpi are not very long, but stout; their length being about one-
half the length of the proboscis.

The ovigerous legs of the males are very characteristic, forming a very elegant curve.
The fifth joint is the longest and the most strongly bent, the sixth joint is a great deal
shorter, the four last joints are very short ; the claw is short and furnished with very
rudimentary teeth (PL IV. fig. 11). The spines of the four last joints are very slender,

REPORT ON THE PYCNOGONIDA. 49

but they are almost all brokeu at the extremity, their numbers are respectively 14, 14,
13, 13. Ou the fourth joint hairs are scarce, on the fifth there are a great many small
hairs vertically implanted on the surface of the joint, the hairs of the sixth and the four
last joints are also numerous: they are larger than those of the fifth joint.

The legs are very slender : in a male of 8 mm. their length is nearly 32 mm. The
second joint is more than twice as long as the third, the fifth joiat is only a little longer
than the fourth ; the sixth is once and a half as long as the fifth. The two tarsal joints
are nearly equal. The claw is short, being one-third the length of the last joint of the
leg. The accessory claw is not half as large as the claw. The first joints of the leg are
nearly smooth, but from the sixth to the eighth they are covei'ed with very small
rouo'h hairs.

The colour of this species is a dark brown, much darker than is the case with the
other species. There are in all three specimens, of these two are mature males (one fur-
nished with eggs), the third is a very small one with broken accessory legs. I consider
it a young male. Genital pores I observed only on the second joint of the two last legs.

Habitat. — This species was found ofi" Kerguelen Island at a depth of 25 fathoms.

Station 149. January 17, 1874. Lat 49° 40' S., long. 70° 28' E. Off Eoyal
Sound. Depth, 25 fathoms.

Observations. — This species shows a certain reseml^lance to Nymphon gracilii^es,
Miers. Yet there are too many small differences for me to feel justified in consider-
ing the two forms as identical. The form of the oculiferous tubercle is not as figured
b}' Bohm, the claws of the mandibles are shorter and not so straight as in Nymiilion
(jvacilipes, Miers (after Bohm, Pycnogon. des Museums zu Berlin, Monatsb. der K. Akad.
der Wiss. zu Berlin, p. 170, 1879) ; the length of the fourth joint of the accessory legs is
different,' the length of the two tarsal joints, of the claw, the colour of the whole animal,
so characteristic in my Nymphon fuscum, is quite different from that described by Bohm
(fast weiss bis hellbriiunlich, Bohm, loc. cit., p. 172). There can be little doubt, how-
ever, that these two forms are closely allied.

Nymp)hon brevicauclatum, Miers (PI. IV. figs. 12, 13; PI. V. figs. 1-5. Nymphon
hispidimi, n. sp., is marked on the plates).

Nymphon hrevicaudatuin, Miers, Ann. and Mag. of Nat. Hist., vol. xvi. p. 107, 1875 ; Crustacea of
Kerguelen Island, Phil. Trans. Lond., vol. clxviii. (extra vol.) pp. 200-214, pi. xi. fig. 8, 1879.

Nijmphon Iwrridmn, Bohm, Pycnogoniden des Museums zu Berlin, Monatsber. der K. Akad.
der Wiss. zix Berlin, 1879, p. 172, taf. i. fig. 3-3/.

Descripition. — The body of this species is very robust, and has the lateral processes
scarcely separated. The proboscis is comparatively short and bears a small mouth; the

1 Bohm, loc. cit., taf. i. fig. \0, represents the si.\tli joint of tlie ovigtrous leg as furnished with (k-nticulated spines. Of
course this is a mistake.

(ZOOL. CH.'iLL. EXr. PART X. — 1881) K 7

50 THE VOYAGE OF H.M.S. CHALLENGER.

&st segment of tlie l^ody is considerably swollen at the base of the mandibles, constricted
posteriorly, and shows a faint line at the beginning of the first true thoracic segment.
The abdomen is comparatively long. The upper surface .of the body is armed with
numerous spines, forming in the middle of the segment star-like groups (PI. IV. fig. 12),
and scattered more irregularly on the lateral processes ; near the end of these a row
of stronger spines is observed. The oculiferous tubercle is, especially in the females,
highly elevated, and shows four dark eyes separated by a cross-like spot. The oculiferous
tubercle is placed on the cephalic part of the first segment, between the two ovigerons
legs.

The mandibles are very long, the first joint being much longer than the proboscis ;
the second joint is shorter and strongly curved, the claws being placed almost trans-
versely before the mouth. The immovable claw is more strongly curved than the
movable one ; the spines on the claws are numerous, l3ut they are almost equal and of
the same length. Both joints are covered with numerous small hairs, stronger ones being
found at the end of the first joint (PI. V. fig. 2).

The palpi arc not very hairy. The second joint is l^y far the longest, the fourth is
the shortest, the fifth very slender. The whole length of the palpus is about twice the
length of the proboscis (PL V. fig. 1).

The ovigerous legs of the males are not quite so long as the body. The fifth joint
is the longest, and is considerably swollen at the extremity, the sixth joint is a great deal
shorter, the seventh to the tenth joints are very short, the claw almost of the same length
as the last joint. The ovigerous legs are very strongly bent and not very hairy. The
denticulated spines of the four last joints are sharply serrated and not numerous, their
numbers being respectively 3, 3, 2, 3 (PI. V. figs. 3, 4). The claw is furnished with a
row of acute spines.

The ovigerous legs of the females are still shorter than those of the males. The
relative length of the joints is the same, but the fifth joint is not swollen at the
extremity. The leg is not curvBd as is the case with that of the male.

For a species of NymjjJion the true legs are uncommonly short : a female of 6 mm.
has a leg of only 14 mm. The second joint is not cpiite twice as long as the first or
third, the three following joints are almost of the same length, and comparatively robust,
especially the fourth joint of the female. The two tarsal joints, the second of which is
the longer, are very slender and almost smooth, together about as long as the sixth joint.
The claw is about as long as one-third of the length of the second tarsal joint, the auxiliary
claws are very small. The legs are very haiiy. These liaii's vary greatly in size and
strength, and are not placed in regular rows. The dorsal surface of the leg especially is
covered l.iy a large quantity of stronger spines. The genital pores of the females are very
large and visiljle on the second joint of every leg. Those of the males are small, and
found only on the second joints of the two last legs.

REPORT ON THE PYCNOGONIDA. 51

I wish to point out as a very interesting peculiarity of this species, that I observed a
female specimen with highly developed ovaries in the fourth joint of its legs, which bears
a distinct egg-mass on its ovigerous leg. The shape of the ovigerous leg is almost
identical with that of a male. In other respects it looks quite like a female.

Habitat. — This sjDccies seems to abound in the neighbourhood of Kerguelen Island.
Miers {loc. cit., p. 213) only says that several specimens were collected at this island, but
Bohm {loc. cit., p. 177) mentions specimens collected in Royal Sound, Irish Bay, and
Great Whale Bay, from a depth of 15 to 65 fathoms.

The Challenger brought specimens home from Station 149. January 17, 1874. Lat.
47' 40' S., long. 70° 20' E. Off Royal Sound. Depth, 25 fathoms.

January 20, 1874. Royal Sound. Depth, 28 fathoms.

January 29, 1874. Off Christmas Harbour. Depth, 120 fathoms.

Observations. — After a close examination of the numerous specimens of this Pycno-
gonid, I at first believed it to be different from the Nymiihon hoi'rklum of Bohm, so I gave
it the name Nymphon hispidum, which name is still to be found on Plates IV. and
V. of this Report. After a renewed examination, and having acquired, I believe, by
continuous study some knowledge of the relative value of characteristic marks, I think
there can be no doubt about the identity of Bohm's species and the specimens brought
home by the Challenger. Unfortunately the two plates are printed off, and thus Ijear
the name originally proposed by me.

However, the name proposed by Bohm ought also to give place to another, viz.,
that of Miers. The description of Mr Miers originally published was too short and insuf-
ficient, therefore Mr Bcihm was c[uite justified in considering his specimens as distinct
and proposing for them the new name Nymphon Jiorridum. This happened in 1879.
In the same j^ear Mr Miers published a more detailed description with figm'cs, which
made it certain that Bohm's, Mier's, and my specimens belonged to the same species ; this
must, I think, bear the name originally applied to it by Mr Miers.

The latest description of this author, however, is by no means exhaustive ; his figures
are very small, and when he says that the number of claws at the end of the leg is two,
it is evident that he has not studied the details with a high enough power.

Bohm's description and drawings are much superior to those of Miers ; they difier
from mine in the following respects : — On the dorsal surface of the body he figures rows of
hairs between the different segments, whereas I observed star-like groups of hairs. He
gives the mandibles a much more elongated form, and furnishes the claws with very
irregular teeth. On the legs, Bohm says, the hairs and spines are arranged in regular
rows, whereas I failed to observe this regularity. The two tarsal joints as figured liy
Bohm are nearly of the same length, but I always observed that the second was much
longer than the first. Minor differences in the form of the eyes, distril^ution of the hairs,
&c., it is unnecessary to discuss. The more important ones which I have pointed out

52 THE VOYAGE OF H.M.S. CHALLENGER.

must perhaps partly be attributed to inaccuracy ; they may have been occasioned by the
circumstance that Bohm's material was much more limited than mine. Bcihm doubts
whether he has a male example or not, whereas I had a dozen at my disposal, five of
which were furnished with eggs.

Nymphon iJerlucidum, n. sp. (PL V. figs. 6-10).

Diagnosis. — Body and legs very slender, pellucid and smooth. Second joint of the
palpi elongated, much longer than the third. Second joint of the feet more than twice as
long as the third. First tarsal joint uncommonly short. Accessory claws.

Description. — This is a very small and a very fine species, the most transparent
form of Nymphon I ever observed. The proboscis is robust, yet very long, much longer
than the first segment of the body. There is no interval between the lateral process
of the ovigerous leg and that of the first true leg, but the intervals between the other
lateral processes are very large. The abdomen is small. The eyes are obsolete : a veiy
small tubercle without pigment is all that is to be seen.

The mandibles have the first joint as long as the proboscis, the second small with
very long claws, the immovable claw is strongly curved at the extremity. The number
of spines on these claws is much more limited than in any of the other species of
Nyinphon, being four on the movable claw and only five on the immovable one.
The mandibles are scarcely hairy : a few stronger hairs are observed at the end of the
first joint, and again at the origin of the movable claw.

The palpi are not very long, once and a third as long as the proboscis. They are
slender, the second joint being comparatively much longer than the thii'd joint, and
nearly as long as the three last joints together. They are covered with very small hairs.

The ovigerous legs are short : 4 J mm. in a male of 5 mm. ; the fifth joint is the
longest, considerably swollen at the extremity ; the sixth is a great deal shorter and
feebly bent ; the four last joints are very short, the claw being half the length of the last
joint. The difierent joints are covered all over with very minute hairs. The spines of
the four last joints are broad, but very small and almost show the hand form (PI. V.
fig. 9). They are not very numerous, their numbers being respectively 7, 4, 4, 5. The
claw is furnished with some small spines (PI. V. fig. 8).

The legs are slender, but not very long, only two and a half times as long as the
body. The second joint is twice as long as the first and third ; the fifth is longer than
the fourth, and the sixth is the longest. The two tarsal joints are highly characteristic
on account of the shortness of the first, and the strong spines placed along that side of
the. second which is opposite the claw. The length of the accessory claws is not half the
length of the claw. The legs are covered with small hairs, stouter ones being placed on
the fifth and sixth joints, and at the end of the joints. I have figured the two tarsal
joints in fig. 10, Plate V.

REPORT ON THE PYCNOGONIDA.

53

The only specimen of this species collected l)y the Challenger is a male fm-nished with
genital jiores on the second joint of the two last legs.

Habitat. — This small species w^as dredged during the Challenger Expedition between
Celebes and Halmahera.

Station 196. October 13, 1874. Lat. 0' 48' S., long. 126° 58' E. Depth, 825
fathoms. Bottom temperatm^e, 2 '4° C. Sea l)ottom, rock.

Observations. — This fine species is highly interesting, Ijeing among the slender
species of Nymplion, the only one in which the form of the two last joints of the leg
shows a remarkable likeness to that of the same joints of most other genera of Pycno-
gonida. This, however, is not the only characteristic point ; a second is that the claws
of the mandibles are not armed wdth a row of very numerous spines as in the other
species of Nymplion, but only with three, four, or five spines. The species is blind, yet
the depth from which it was In-ought up was only 825 fathoms, whereas Nymphon
meridionale, Hoek, e.g., lives at a depth of 1674 fothoms and has four distinct eyes.

Ascorhynchus, G. 0. Sars.

Ascorhynchus glaber, n. sp. (PL VI. figs. 5-9 ; PI. XV. fig. 16).

Diagnosis. — Proboscis one-tlm-d of the total length of the Ijody. Aljdomen half as
long as the proljoscis. Body and legs almost entirely smooth, with the exception of three
strong spines placed dorsally on the hinder margin of the first three thoracic segments.

Description. —

Length of the proboscis,

.

8i mm

Length of the trunk,

ul „

Length of tlie abdomen,

.

4 „

Total length of the body, .

.

26 „

Length of the cephalothoracic

segment.

7. „

Length of the third leg,

c!-\-\ar'icia icj a+^'/'^nn- tto'H nr^rt

39 „

intervals between the lateral processes. The proboscis is very stout, pyriform, distinctly
triangular in transverse section ; each of the three sides of the proboscis is longitudinally
furrowed in the middle ; at its extremity the proboscis is sharply pointed, the mouth is
small and triangular. The proboscis is distinctly divided into a fore, middle, and hinder
part, the latter tapering towards the extremity, where it articulates with the cephalo-
thorax (PI. XV. fig. 16). The length of the cephalothoracic segment is very con-
siderable, being aljout half that of the trunk. Anterior to the insertion of the palpi it is a
little narrower, and at the front part it l)ears the mandil^les, between which it shows
a small azygous knob. On the dorsal surface a slight elevation is ol)served between the
two palpi, whereas behind the middle, almost exactly l^etween the two ovigerous legs, the

54 THE VOYAGE OF H.M.S. CHALLENGER.

same surface bears a very high conical oculiferous tul^ercle, which as a seusc organ is
quite rudimentary, being destitute of lenses, pigment, &c. A second dorsal conical
elevation is found at the hinder margin of the cephalothorax, and similar very strong
spines are also observed at the hinder margin of the two following thoracic segments
(PL VI. fig. 5). At the point where these thorns arise the segments are a great deal
wider than the anterior part of the following segment. The abdomen is comparatively
long l)ut very narrow, being only a little swollen at the extremit}-. The lateral pro-
cesses for the attachment of the ovio;erous leas are short, those for the true legs
comparatively very long.

Both specimens of this species brought up l)y the Challenger are furnished with
three-jointed mandibles. Those of the younger specimen bear at the extremity of the
thii'd joint slender and curved claws (PL VI. fig. 7) ; the older specimen, on the
contrary, shows rudimentary straight and very small claws, the movable claw being
furnished with a slender thread (PI. VI. fig. 6). The latter specimen is a male, and
there is no reason why it should not be considered as fuU-gro'uai.

The form of the palpi is nearly the same as in the other species of Ascorhynclms.
The first two joints are extremely small, the third is the longest, the fourth is short, the
fifth about twAcQ as long, and narrow in the middle, the sixth is very short; of the seventh
to the tenth joints, the first is the shortest, the second the longest. With the exception
of some extremely small hairs on the last joints, the surface of the palpi is quite smooth.

The ovigerous legs have the fourth joint the longest, the fifth shorter and swollen
towards the extremity, the sixth about half as long as the fifth, and yet more
swollen towards the extremity ; of the four last joints the first is the longest, and the claw
at the end of the tenth joint is extremely small. The denticulated spines are placed in
difi"erent rows, each row showing spines of about the same size, whereas those of difi"crent
rows vary greatly (PL VI. fig. 8).

Of the legs the first pair is a great deal less developed than the three following ; its
total length is only 30 mm., whereas that of the third pair is fully 39 mm. Of the latter
leg the second joint is quite as long as the first or third joint, the fourth joint is the
longest, the fifth joint is a little shorter than the fourth, the sixth again a little shorter
than the fifth ; of the two tarsal joints the first is a little shorter than the second, the
claw is not quite half as long as the second tarsal joint. There are no accessory claws
(PL VI. fig. 9). The claw of the first leg is extremely minute, yet distinct. The legs
are almost hairless ; yet the fourth and the fifth joints cannot be called smooth, as
they are furnished with rows of knobs, corresponding with the knobs I observed on the
leg of Nymjyhon hamatnm, Hock.

The animal from which all the above measurements, &c., are taken is a male ; its
genital orifices are found ventrally'^^on the second joint of the two posterior legs. Its
colour is a beautiful orange-yellow.

EEPOET OX THE PYCNOGONIDA. 55

Habitat. — This iuteresting species was dredged during the Challenger Expedition at
Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E. Depth of the sea,
1375 fathoms. Bottom temperature, 1"5° C. Sea bottom, globigerina ooze.

Observations. — This species is, I beheve, closely allied to Ascorhynchus abyssi,
G. 0. Sars. It can, however, easily be distinguished from that species.

1 . By the proboscis, which is as long as the trunk in Ascorhynchus abyssi, and only
two-thirds the length of the trunk in Ascorhynchus glaber.

2. By the lateral processes of the Ijody, which in Ascorhynchus abyssi, " vix," iu
Ascorhynchus glaber are visibly longer than the l^readth of the body.

3. By the oculiferous tubercle, which in Ascorhynchus abyssi is denticulate and
placed on the fore part of the first segment, while in Ascorhynchus glaber it is behind the
middle of the cephalothorax and quite smooth.

4. By its three-jointed mandibles.

5. By the legs, which are covered with short hairs and are twice as long as the body
in Ascorhynchus abyssi; in Ascorhynchus glaher, on the contrary, they are almost smooth,
and are only once and a half as long as the body.

6. By the length of the body, 10 mm. in the Ascorhynchus abyssi, and 26 mm. iu
Ascorhynchus glaber.

Ascorhynchus minutus, n. sp. (PI. VI. figs. 10-16).

Diagnosis. — Proboscis not c[uite one-third of the total length of the body. Abdomen
one-thnd the length of the proboscis. Body and first joints of the legs furnished dorsally
with numerous strong spines.

Description. —

Length of tlie proboscis, ....... 2 mm.

Length of the trunk,

Length of the abdomen.

Total length of the body, .

Length of the cephalothoracic segment,

Length of the thu'd leg,

3-75
0-6.5
6-4
2-3
9 0

The hodj of this nice little species is slender, and the intervals between the lateral
processes are great (PI. VI. fig. 10). The body and legs are almost eutkely smooth, single
hairs being found only at the distal extremities of the joints of the legs. The proboscis
is triangular, almost of the same form as that of Ascorhynchus glaber; it is distinctly divided
into three parts, the middle part l:)eing considerably swollen. The cephalothoracic seg-
ment is comparatively long, l^eiug as long as the remaining part of the Ixxly including
the abdomen. The oculiferous tubercle is situated in front of the middle of the cephalo-
thoracic segment and is much elevated ; the eyes are rudimentary. A distinct knob is

56 THE VOYAGE OF H.M.S. CHALLENGER.

to Ije seen at the frout margin of the segmeut between the origiu of the two mandibles.
The three following thoracic segments are short ; the two middle segments are
furnished like the cephalothoracic segments dorsally at their hinder margin with an
elevated prickle. The lateral processes which serve for the insertion of the legs, are of
considerable length; at their extremities they bear a strong prickle, which is not quite
so Ions; as those on the middle of the dorsal surface.

The mandibles consist of a single joint, bearing at its extremity a rudimentary
triangular second joint.

The palpi are slender and comparatively long ; the first two joints are extremely
small, the third joint is the longest ; the relative length of the other joints is nearly the
same as in the palpi of Ascorhynchvs glaher. The distal extremity of the fifth joint and
the whole surface of the four following joints show on the one side numerous haii-s
of the curious form observed and descriljcd by Bohm for Ascorhynchus ramipes,
Bohm (sp.) {Gnamiitorliynchvs rami2'>€S, Bohm) (PI. VI. fig. IG).

The ovigerous legs are comparatively short, 5 mm. in the specimens of 6 '4 mm. The
first joint is very small, the two following are a little longer, the fourth and fifth are
very long, the sixth a great deal shorter; the four last joints (PL VI. fig. 12) are very
short, and about the same length, the claw is not so extremely short as in Ascorhynchus
glaher. The denticulated spines are placed in three distinct rows (PI. VI. fig. 13).

The first joints of the legs are furnished dorsally with strong prickles, like those of the
dorsal surface of the l)ody and the lateral processes. The first joint of the leg is furnished
with two, the second joint, which is Ijut little longer than the first, with a single prickle.
On the third joint, which is nearly as long as the first, no prickles are to be seen. The
fourth is shorter than the fifth ; the latter, the longest of all, is also a little longer than
the sixth joint. Of the two last joints the first is a little shorter than the second (PL
VI. fig. 14). The claw is longer than half the length of the second tarsal joint.
Accessory claws arc wanting. The first pair of legs, which is much feebler than the
three following paii's, has a very small claw (PL VI. fig. 15).

Both specimens of this species collected during the cruise of H.M.S. Challenger are
males. I observed small genital pores on the two hinder legs at the place which, as
fiir as my knowledge goes, they invariably occupy. One of these males bears larvae,
for the description of which see below.

Habitat. — The specimens of Ascorhynchvs mhmtus were dredged in the neighbourhood
of Melbourne, at

Station 161. April 1, 1874. Ofi' entrance to Port Philip. Depth, 38 flxthoms. Sea
bottom, sand.

Observations. — This species seems to l)e nearly allied to Ascorhynchus 7'amipes, Bohm
(sp.). Yet it may be easily distinguished from it ])y the follomng characteristics: —

1. The total length of the Ijody of Ascorhynchus ramipes is 11 mm., of the proboscis

EEPORT ON THE PYCNOGONIDA.

57

3 mm., whereas the length of the body of Ascorhynchus minutus is only 6'4 mm., and
that of the proboscis 2 mm.

2. The abdomen of Ascorhynchus ramipes is about as long as the proboscis, while
that of Ascorhynchus minutus is nearly one-third the length of the proboscis.

3. On the dorsal surface the thoracic segments and the lateral processes in Asco-
rhynchus ramiiJes show round knobs, in Ascorhynchus minutus distinct prickles.

4. The four last joints of the ovigerous legs of Ascorhynchus ramipes are furnished
with a single row of denticulated spines; those oi Ascorhynchus minutus with three distinct
rows. (I think this difference is not a real one : Bohm's observation and description will,
no doubt, in this respect, be found deficient.)

5. The first true leg of AscorhyncMis ramipes is not furnished with a claw, that
of Ascorhynchus minutus has a small, but distinct claw.

Ascorhynchus oHhorhynchus, n. sp. (PI. V. figs. 11-13; PI. VI. figs. 1-4; PI. XV.
figs. 14, 15).

Diagnosis. — Proboscis almost half the length of the body. Abdomen not quite one-
third the length of the proboscis. Dorsal surface with a row of prickles, also the lateral
processes.

Descrip)tion. —

Length, of the proboscis.

10 mm.

Length of the tmnk, . . . .

^ „

Length of the abdomen, . . . .

3 „

Total length of the body, . . . .

m „

Length of the palpi, . . . .

. u „

Length of the thiid leg, . . . .

50 „

Length of the ovigerous leg.

20 „

The body of this species is very slender and almost smooth. The proboscis does
not incline to the ventral side, and is not so much swollen as in the other species of
Ascorhynchus, consequently the form is not pyriform, but rather club-shaped. The
proboscis shows longitudinal furrows ; the mouth is, as in the other species, triangular
and very small (PL XV. fig. 14).

The cephalothoracic segment is comparatively short, being only half as long as the
proboscis ; the mandibles and the palpi are placed on distinct prominences. The
oculiferous tubercle is elevated and conical, and furnished with four distinct eyes ; the
lateral processes for the ovigerous legs are very small, those for the first pair of true legs as
weU as those for the following legs are of considerable size. The lateral processes of the true
legs are widely separated, thus contributing to the slender appearance of the whole body.
Posteriorly the cephalothoracic, as well as the two following segments, are consider-
ably elevated dorsally, while the anterior part of the following segment is much narrower,

(ZOOL. CHALL. EXP. PART X. 1881.) K 8

58 THE VOYAGE OF H.M.S. CHALLENGER.

and placed lower; these three elevatioDS bear in their centre strong conical prickles
(PI. V. fig. 11). Similar prickles, though a little smaller, are also to be observed dorsally
on the lateral processes close to the margin of the articulation with the leg.

The mandibles of the female specimen (the only one procured) are small, but
distinctly three-jointed. The first two joints are extremely slender and of equal length ;
the third joint (PL VI. fig. 1) is very small, and furnished with rudiments of claws
only.

The palpi are very slender, and ten-jointed. The first joint is small, the second —
correctly observed by Bohm in Ascorhynchus ramipes — much smaller still, the third the
longest of all, the fourth small, the fifth not quite half as long as the third, the sixth
about the same length as the fourth, and the seventh twice as long as the sixth ; the
three last joints decrease regularly in length. The first four joints are nearly smooth,
distinct hairs are observed towards the extremity of the fifth joint, and on the five
following joints (PI. V. fig. 13). These hairs exhibit the curious form observed by
Bohm in the hairs of the palpi of Ascorhynclms ramipes; they are also found in
Ascorhynchus minutus (PI. VI. fig. 16).

The first three joints of the ovigerous legs are small, the fourth is the longest ;
the fifth and sixth, which are a great deal smaller, and the seventh, which is extremely
small, are quite straight. The last three joints are placed at right angles to the fore-
going. All the joints are almost entirely smooth, with the exceiDtion of a few hairs
towards theii" extremities. The claw is very small. The denticulated spines on the
four last joints are placed in three or four rows ; their form can be understood from the
drawing in fig. 3 of Plate VI.

The legs are more than twice as long as the body ; the second joint is twice
as long as the first, the third is as long as the first. The fourth joint is considerably
swollen, the fifth nearly as long but a great deal narrower than the fourth, the sixth
much narrower and a little longer also. Of the two tarsal joints the second is longer
than the first and considerably curved, and the claw is nearly half as long as the second
tarsal joint. The hairs on the legs are very small, and can only be seen with the micro-
scope. Some stronger hairs are placed at the distal ends of the joints.

The single specimen brought up by the dredge is a female (having the fourth joint of
the legs swoUen and the ovigerous legs feeble). The genital pores are not very small, and
are found ventrally at the end of the second joint of every leg (PI. XV. fig. 15).
Judging from the whole exterior of the animal, it is a full-grown, or nearly full-grown,
specimen.

Habitat. — The only specimen of this species was dredged north of New Guinea, at
Station 219. March 10, 1875. Lat. 1° 50' S., long. 146° 42' E. Depth of the sea,
150 fathoms. Sea bottom, mud.

Observations. — This curious form of Ascorhynchvs does not show any remarkable

REPORT ON THE PYCNOGONIDA.

59

affinity with any of the other forms of Ascorhynchus described. Judging from the shape
of the proboscis, it comes nearest to some of the species of Colossendeis. Yet in that
genus the mandibles in the full-grown' animal have totally disappeared, whereas Ascor-
hynchus orihorhynchus in all probability has these appendages in the adult state. I
do not believe, however, as I have said before, that this diifereuce is in reality very
important, especially since I have observed among the specimens of Colossendeis gracilis
one furnished with long three-jointed mandibles, while these appendages were totally
wanting in the other specimens of the same species.

Oorhynchus, n. gen.

Diagnosis. — Proboscis ovate, inserted ventrally on the cephalothorax at a con-
siderable distance from the front margin. Mandibles rudimentary ; palpi nine-jointed.
Ovigerous legs ten-jointed, the four last joints not furnished with one or more rows of
denticulate spines.

Oorhynchus auchlandice, n. sp. (PI. VII. figs. 1-7).

Diagnosis. — Oculiferous tubercle horizontally directed forwards. Mandibles repre-
sented by single-jointed club-shaped bodies. First tarsal joint of the legs extremely small,
auxiliary claws wanting. Abdomen very long, once and a half as long as the proboscis.

Description. —

Length of the proboscis.

1 mm

Length of the cephalothorax,

0-9 „

Length of tlie trunk,

2

Length of the abdomen,

1-5 „

Total length of the body,

4-2 „

Length of the leg, ....

5-5 „

This very curiously-shaped Pycnogonid has the cephalothoracic segment short but
very broad, furnished at the front with. a long cylindrical oculiferous tubercle which
projects horizontally beyond the extremity of the proboscis. The oculiferous tubercle is
furnished with four eyes, two placed dorsally, and two ventrally ; the latter two are
the smaller. The cephalothorax is armed at the two corners with curiously-shaped spines
also projecting forwards, and above the attachment of the first pair of legs bears a couple
of long hairs placed on small knobs. Similar pairs of hairs or thin spines are also
observed on the two following thoracic segments on the dorsal surface between the lateral
processes for the insertion of the legs. The rest of the surface of the body is entirely
smooth. The three thoracic segments are small, and the lateral processes are separated
by small intervals. The abdomen, on the contrary, is very long, being once and a half
as long as the proboscis. The abdomen shows on both sides a row of comparatively long
and projecting haii-s.

60 THE VOYAGE OF H.M.S. CHALLENGER.

The proboscis is inserted ventrally on the cephalothorax, at a considerable distance
from the front margin ; it is of a distinctly ovate form, and bears the small triangular
mouth surrounded by slightly swollen lips.

The mandibles are represented by one-jointed robust club-shaped bodies, placed at
the front margin of the cephalothorax on both sides of the oculiferous tubercle, but not
reaching quite so far as that organ. The mandibles are covered all round with strong
hairs, placed at right angles to the surface, and when the mandibles are viewed from
below and anteriorly, the round cicatrice is observed where in all probability, at an earlier
date, a second joint has been inserted.

The palpi are nine-jointed and placed close to and on both sides of the base of the
proboscis. The first joint is very short, the second is the longest of all and directed
forwards, the third again is short, the fourth almost as long as the second, and bent so as
to form an angle with the first three joints. The fifth joint is again very short, the
four last joints are nearly of the same length ; the sixth, however, is the longest, and the
eighth the shortest. All the joints are furnished with very strong hairs, which are
longest on the third and fourth joints, and decrease in size though not in number
towards the extremity of the appendages.

The ovigerous legs are strongly curved. Of the first three joints, which are not
so very small as is the case in other genera, the second is the longest, being nearly
twice as long as the first. The fourth and fifth joints are nearly of the same length and
are the longest of all. The sixth is not quite half as long as either of the two foregoing
joints ; of the seventh to the tenth the first is the longest, the second much shorter
and the third a little shorter, while the last joint is extremely small and may easily
be overlooked. The first three joints are almost smooth, the two following are furnished
with very small hairs, and the sixth to the tenth mth not very numerous Ixit longer
hairs. The last joint but one is armed with one, the last with two not very strong,
comparatively broad, and slightly serrated spines. The total length of the ovigerous
leg is not quite so long as that of the body without the abdomen.

The legs are comparatively strong and very hairy (PL VII. fig. 6). The lateral
processes are furnished wdth numerous small and curved spines ; the first three joints of
the leg are small and nearly of the same length. The fourth joint is twice as long as the
third, and on the dorsal surface beyond the middle it bears a tubular process,' directed
backwards towards the origin of the leg. The fifth and sixth joints are the longest in
the leg, and are nearly of the same length. The fifth joint, however, is a great deal more
slender than the fourth, and the sixth much more so than the fifth. The first tarsal joint
is extremely small, the second long and distinctly curved ; the claw is scythe-shaped,
and accessory claws are wanting. All the joints are furnished with long and strong
hairs, standing at right angles to the surface ; the last joints are covered with much more
delicate hairs.

REPORT ON THE PYCISrOGONIDA. 61

The only specimen of this curious species dredged by the Challenger Expedition is
a naale ; the second joints of the two last legs bear on the ventral side distinct rounded
tubercles, and at the tips of these knobs the small genital pores are to be observed.

Habitat. — Oorhynchus aucklandicB was di'edged at Station 169. July 10, 1874.
Lat. 37° 34' S., long. 179° 22' E. Depth, 700 fathoms. Temperature of the bottom,
4' 2° C. Sea bottom, grey ooze.

No other species of Pycnogonid was dredged at this station.

Observations. — No doubt the genus Oorhynclius is nearly allied to other genera of the
same group, and especially to the genus Achelia. Although the shape of the body is
widely different, we find in this genus likewise rudimentary mandibles, ovigerous legs
furnished with rudimentary denticulated spines and with the four last joints, hi general,
almost of the same shape as those of Oorhynchus. In both genera the genital pores of
the males are placed on tubercles situated ventrally on the second joints of the two
posterior legs. They are distinguishable by the shape of the body, which is much
more concentrated and rounded in Achelia, by the number of joints in the palpi, and
by the absence of auxiliary claws from the legs of Oorhynchus, whereas all the species of
Achelia, as far as is known at least, are furnished with them.

Colossendeis, Jarzynsky.

Colossendeis gigas, n. sp. (PI. VIII. figs. 1, 2 ; PI. X. figs. 1-5).

Diagnosis. — Proboscis bottle-shaped ; cephalic part of the cephalothoracic segment
triangular and distinct ; eyes obsolete ; thuxl joint of the palpus longer than the fifth,
palpus as long as the body ; claws of the legs minute.

Description. —

Length of the prohoscis,

Length of the trunk (with the ahdomen),

Length of the ahdomen,
Length of the palpus,
Length of the ovigerous leg, .
Length of the leg of the third pair,

The body of this gigantic Pycnogonid is robust ; nevertheless there are distinct
intervals between the lateral processes. In the large specimen (No. 1) the surface of the
body is quite smooth ; the palpi alone are furnished with strong hairs, and the ovigerous
legs with small ones, while the extremely small hairs on the legs can only be seen with
a lens. ' In the younger specimens the hairs are by no means so scarce. Those on the
trunk, the proboscis, and the lateral processes are still very small, but the hairs on the
legs are much more distinct, and, especially at the distal extremities of the joints of the
legs, rows of short strong hairs may be observed ; finally, the palpi and the ovigerous legs

No. 1.

No. 2.

No. 3.

No. 4.

47-5 mm.

29 mm.

15 mm.

22 mm

32-5 „

20-5,,

14 „

13 „

6

3-5 „

2

2-7 „

81

53 „

1

38-5 „

137

90 „

49 „

60 „

301

211 „

112 „

143 „

62 THE VOYAGE OF H.M.S. CHALLENGER.

show in these younger animals strong but not very long hairs projecting vertically from

the surface.

The proboscis is bottle-shaped and very long. The lower stalk-like and more slender
part (the neck of the bottle) can easily be distinguished from the middle part which is
considerably swollen, whereas the anterior part is a little narrower again, but by no means
so narrow as the stalk-like part. The mouth is triangular and very large. The cephalic
part of the cephalothorax in this species is sharply divided from the thoracic part, the
latter forming a true first thoracic segment. The cephalic part has, when viewed dorsally,
a triangular shape ; it bears almost exactly in the middle a very blunt oculiferous tubercle.
In the younger specimens this tubercle is conical, much more elevated and pointed at the
extremity ; it shows neither pigment nor lenses.

The four thoracic segments are closely united, so that their terminations are not
visible; the origin of the lateral processes for the insertion of the legs is, on the contrary,
distinctly marked by a line.

The abdomen is club-shaped and not longer than -^^ih of the total length of the
body. As in the other species of the genus Colossendeis it is connected with the thorax
by means of an articulation.

The palpi are as long as, or a little longer than, the body. The two first joints are
extremely small, the third is very long, the longest of all the joints of the palpi ;
it is a little swollen at its beginning and again at the extremity. The fourth joint is
again very small, the fifth almost as long as the third ; the sixth is again much
shorter, nearly one-fourth the length of the fifth. Of the last four joints the seventh
is the longest, the eighth being only half its length, and the ninth and tenth,
which are of equal length, being still shorter than the eighth. The first four joints
are almost quite smooth, while the following joints are furnished with short but rather
strong hairs.

The ovigerous legs, as in the other species of this genus, are attached close to the
base of the palpi. The lateral processes for the ovigerous legs are found at the ventral side,
immediately behind and close to the first joint of the palpi. The first three joints of
the ovigerous legs are extremely short, not longer than they are broad. The fourth
joint is very long (almost as long as the proboscis) and not inconsiderably swollen
at the extremity. The fifth joint is again short, and this joint serves — as was
observed by Wood-Mason ^ — to elbow the ovigerous leg. The sixth is still longer than
the fourth and exactly as long as the proboscis. The last four joints gradually become
more slender ; they are nearly equal in length and very short, the length, however,
decreases a little from the seventh to the tenth joint. At its extremity the last
joint bears a very small hook-like curved claw, the inner surface of which is quite
smooth.

' Wood-Mason, Ou Ehopalorhynchus hroyeri, Joiu-u. of tlie Asiatic Soc. of Bengal, Calcutta, vol. ii., 1873.

EEPORT ON THE PYCNOGONIDA. 63

The last four joints describe a spiral curve; so that the tenth lies parallel to the seventh.
Their inner surfaces are furnished with numerous rows of very flat spiaes. In the oldest
specimen there are about twelve rows, making the total number of spines for every joint
several hundreds. None of these spines, however, show the original shape ; they are all of
them broken by use or by age, and those placed towards one side especially are very short
and rudimentary. On the other side they grow longer (PI. X. fig. 2), and, covered
by this outermost row of longest spines, some short thimble-shaped knobs (fig. 5) are to
be observed. Such is at least the condition of the flattened spines on the last four joints of
the ovigerous legs of the gigantic male dredged at Station 146. The specimen second
in size is a great deal smaller and in all probability is not quite adult. Here the
spines, placed in about eight rows, show a much more regular shape (fig. 3) ; their
margins are furnished anteriorly with very small hairs. These hairs are rather
firm, are not at all injured by the action of alcohol, and must not, I believe, be con-
sidered as cilia. The spines are in the middle a great deal narrower, and broader again
at the extremity, the broader part has the shape of a rhomb. In the earliest stage the
spines are much smaller and beautifully spatulate. The small hairs extend here to beyond
the middle (PL X. fig. 4).

This species has exceedingly long legs. The first three joints are very small, the
three following very long ; the fourth is the longest, the fifth a little shorter, the sixth
again a little shorter ; the two last joints are small again ; the second tarsal is only half
as long as the first. The claw measures about one-third the length of the second tarsal
joint ; there are no auxiliary claws. The joints of the leg, from the fourth to the
eighth, gradually decrease in tliickness. The hairs, which on the legs of the large adult
specimen are extremely smaU and sparse, are stronger and more numerous on -the legs of
the younger specimens.

In regard to the sexes of the specimens of this species dredged during the voyage of
the Challenger, I am sure only of the gigantic specimen. This is a male ; it shows genital
openings on the ventral surface not very close to the distal margin of the second joint of
the two posterior pairs of legs. About the other specimens, whose genital openings I fliiled
to observe, I am in doubt whether they are young males or females. The colour of the
specimens is light yellow, nearly the same as that of all other Pycnogonids preserved in
spirits. The large full-grown male, however, is of a much darker orange-red colour, with
beautiful red bands over the proboscis, at the extremity of the joints of the legs, &c.

Habitat. — Colossendeis gigas, seems to occur in difi"erent parts of the southern
ocean ; it was dredged at

Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E. Depth of the
sea, 1375 fathoms. Temperature of the bottom, 1'5° C. Sea bottom, globigerina
ooze.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. Depth of the

64 THE VOYAGE OF H.M.S. CHALLENGER.

sea, 1600 fathoms. Temperature of tlie bottom, 0"8° C. Sea bottom, globigerina
ooze.

Station 300. December 17, 1875. Lat. 33° 42' S., long. 78° 13' W. Deptli 1375
fathoms. Bottom temperature, 1"5° C. Sea bottom, globigerina ooze.

Of all the species of this genus known at present, this species of Colossendeis shows
Ijy far the greatest affinity with Colossendeis leptorhynchus, which I shall describe further
on. The latter species, however, is much more slender,

Colossendeis leptorhynchus, n. sp. (PL VIII. figs. 3-7).

Diagnosis. — Proboscis almost cylindrical. Cephalic part of the cephalothoracic seg-
ment distinctly separated from the thoracic part ; eyes obsolete ; third joint of the palpus
shorter than the fifth ; palpus much longer than the body. Legs and proboscis
extremely slender. Claws of the legs minute.

Description. —

Length, of tlie proboscis, .

Length of the trunk with the abdomen.

Length of the abdomen, .

Length of the palpus.

Length of the ovigerous legs.

Length of the leg of the third pair.

The body, and especially the proboscis and legs, are a great deal more slender than
in Colosse7ideis gigas. The intervals between the lateral processes are not quite so wide
as the thickness of these processes. The surface of the body is quite smooth, but the
palpi and ovigerous legs, and the last five joints of the legs, are furnished with extremely
small hairs.

The proboscis is extremely long, more than twice as long as the trunk ; about the
middle it is slightly swollen. The cephalic part of the cephalothorax is distinctly
separated from the thoracic part. It is elongated, a little more slender towards the end,
and bears on the dorsal surface, about the middle, a small blunt knob as a rudimentary
oculiferous tubercle.

The four thoracic segments are closely united. The abdomen is small, about 1-1 8th
of the total length of the body. The palpi are not very long. The first two and the
fourth joints are extremely small ; the third is long, and the fifth a great deal longer stiU,
The sixth joint is shorter than the seventh, and of the last three joints (fig. 5), the third
is by far the longest. The relative lengths of the joints of the ovigerous legs is the
same as in Colossendeis gigas, Hoek ; the sixth joint is again considerably longer than
the fourth, and the fifth is extremely short. The last four joints decrease in length, and
the claw is very smaU (fig. 6).

The first three joints of the legs are very small, nearly as long as broad ; the following

Male.

Female.

28 mm.

33 mm.

13 „

14 „

2-2 „

2-5 „

35 „

37 „

56 „

57 „

143 „

158 „

REPORT ON THE PYCNOGONIDA. 65

three are very long aud slender, and not inconsiderably curved. Their relative length
is the same as in Colossendeis gigas. Of the last two joints, the first is longer than the
second. The claw is small.

Of this species seven adult and two young specimens were dredged during the
cruise of H.M.S. Challenger. By stretching out the legs parallel wth each other, the
body of the animal assumes a very peculiar aspect.^ Of the eight adult specimens,
seven are females — one only a male. Both the females and the male have genital
openings only on the two hindermost legs, where they are j^laced on the ventral surface
of the second joint of the leg. Perhaps the ovigerous legs of this species, and in that
case probably of the other species of this genus also, have lost their egg-bearing function.
Small capsules filled with numerous eggs were attached to several joints of the legs,
but as these eggs were quite undeveloped, it was impossible to determine whether they
belong really to this animal, or to some other inhabitant of the same locality. The
capsules, I observed, were attached to the fourth joint of the leg in a female, and to the
second joint of the leg in the single male specimen.

Habitat. — This species was dredged at the same stations a.s the foregoing species
{Colossendeis gigas), and also at a fourth station (310).

Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E. Depth of the
sea, 1375 fathoms. Temperature of the bottom, 1*5° C. Sea bottom, globigerina ooze.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. Depth of the
sea, 1600 fathoms. Temperature of the bottom, 0-8° C. Sea bottom, globigerina ooze.

Station 300. December 17, 1875. Lat. 33° 42' S., long. 78° 13' W. Depth of the
sea, 1375 fathoms. Temperature of the bottom, 1'5° C. Sea bottom, globigerina
ooze.

Station 310. January 10, 1876. Lat. 51° 30' S., long. 74° 3' W. Depth of the
sea, 400 fathoms. Temperature of the bottom, 7-9° C. Sea bottom, mud.

Observations — This species is distinguished from the fijregoing by its much more
slender form and shorter palpus. From Colossendeis angusta, G. 0. Sars (Arch. f.
Math, og Naturvid., vol. ii. p. 268, 1877), and other species, it may be easily distinguished
by the dimensions of the joints of the palpus ; for, as far as 1 know, Colossendeis
leptorhijnchiis is the only species of this genus which has the fifth joint of the palpus
considerably longer than the third. The form of the cephahc part of the cephalothorax,
and the extremely small claws at the ends of the legs indicate, I believe, a near relation-
ship between this species aud Colossendeis gigas.

Colossendeis gigas-leptorliynchus.

A single specimen — unfortunately defective — dredged at Station 158, shows to a

1 This, of course, refers to the animal preserved in s^jirits. I observed the same thing in living specimens of Kympho-n-
gradle, Leach, and Pallene brevirosiris, Johnston.

(ZOOL. CHALU EXP. — PART X, — 1881) K. 9

66

THE VOYAGE OF H.M.S. CHALLENGER.

certain extent the characteristics of Colossendeis gigas, and in other respects those of
Colossendeis leptorhynchiis. I therefore wish to consider it as an intermediate form. Its
dimensions arc as follow : —

Lengtli of the proboscis, .....

26 mm

Length of the trunk with the abdomen,

18 „

Length of the palpus, .....

33i „

Length of the ovigerous leg, ....

?

Length of the leg, ......

137 „

As I consider that this specimen is not quite adult, I will not give a detailed de-
scription of it. I only wish to point out that the form of the proboscis, though a little
more slender, quite agrees with that of Colossendeis gigas, whereas the relative length
of the joints of the ^^alpus, and that of the whole palpus, is the same as in Colossendeis
lejitorhynchiis, viz., the third joint of the palpus is 8'5 mm., and the fifth 14 mm. The
total length of the palpus is only three-quarters the length of the body.

The specimen is a young female, with the body almost smooth, and mth legs only
furnished with extremely small hairs.

Habitat. — This curious form was dredged at Station 158. March 7, 1874. Lat.
50° 1' S., long. 123° 4' E. Depth of the sea, 1800 fathoms. Bottom temperature,
0'3° C. Sea bottom, globigerina ooze.

Colossendeis rohusta, n. sp. (PI. IX. figs. 4, .5).

Diagnosis. — Proboscis club-shaped, shorter than the trunk. Body and legs rather
stout, with large intervals between the lateral processes for the insertion of the legs.
Palpi not very long, a great deal shorter than the body, with the third joint longer than
the fifth. Legs not very slender, furnished with a claw, which is almost half as long as
the second tarsal joint. Oculiferous tubercle conical, with four eyes.

Description. —

Length of the proboscis, .

Length of the trunk with the abdomen.

Length of the abdomen.

Length of the palpus.

Length of the ovigerous legs,

Length of the leg of the third pair,

Only a single specimen of this l^eautiful and robust form was dredged. All the
segments of the body are closely united, the cephalic part is comparatively short, and
bears a conical, robust, not much elevated, oculiferous tubercle. This tubercle shows four
distinct eyes, two of which are large and directed forwards, while the two small ones are
directed backwards.

15 mm

18

3-5

25

52

113

REPORT ON THE PYCNOGONIDA. 67

The intervals between the well-developed lateral processes are comparatively large.
The proboscis is not quite half so long as the total length of the body. It is very stout,
and shows a considerable swelling in the middle, and another at the extremity. The
abdomen is small, its length about one-fifth the length of the trunk.

The palpi are comparatively stout, shorter than those of Colossendeis gigas, but
longer than those of Colossendeis leptorhynclms. The first two joints are very small,
the third is by far the longest of all the joints. The fourth is short again, the
fifth only three-fourths as long as the third, the sixth to the tenth are nearly of
the same length, the seventh, however, is a little longer. The joints are almost per-
fectly smooth, with the exception of some very small hairs visible only with the
microscope.

The ovigerous legs have the first three joints short, the fourtli and sixth of about the
same length, and comparatively long. The fifth (the elbow-joint) is short. The four
last joints are almost of the same length, becoming more slender from the first to the
fourth. The claw is small and smooth ; the place of the denticulate spines of the
four last joints is filled up by short strong knobs of a conical or rounded shape. They
are placed on excavations of the chitiuous skin, and with the exception of the two rows
on one side, are placed rather irregularly.

The legs are not very long. Those of the third pair are the longest. The first and
the fourth leg of the right side are, in the Challenger specimen, quite rudimentary. In
the full-grown leg the fourth and the sixth joint have the same length, whereas the fifth
is a little shorter. Of the two tarsal joints the first is longer than the second. The claw
is robust, about half as long as the second tarsal joint.

The only specimen brought home by the Challenger Expedition is a female. Its
genital openings are not very large, and are found ventrally on the second joint of all
the legs.

The animal is entirely smooth, and of a beautiful orange colour.

Habitat. — This species was dredged ofi" Christmas Harbour, Kergueleu, 29th June
1874. Depth of the sea, 120 fathoms.

Observations. — This species cannot easily be confounded with any of the other
species ; it is distinguished by being stout, yet comparatively slender, by the form
of the proboscis, and the presence of four distinct eyes. It is rather a shallow-water
species.

Colossendeis megalonyx, n. sp. (PI. IX. figs. 1-3).

Diagnosis. — Proboscis club-shaped, somewhat bent over to the ventral side. Cephalic
part of the cephalothorax not distinctly separated. Oculiferous tul)ercle conical, with
four eyes. Third joint of the palpus longer than fifth. Body and legs slender. Claws
of the legs as long as the second tarsal joint.

C8 THE VOYAGE OF H.M.S. CHALLENGER.

Description. —

Length of the proboscis,

20 mm.

8 mm.

13-5 mm.

17-5 mm.

Length of the trunk,

10-5 „

8 „

8 „

10-5 „

Length of the abdomen, .

2-5 „

9

1-5 „

9

Total length of the body, .

33 „

Length of the palpns,

26 „

...

...

...

Length of the ovigerous leg,

39 „

...

...

Length of the leg of the third pair,

97 „

...

...

...

The proboscis of this species is club-shaped, a little bent over to the ventral side ;
longer than the trunk with the abdomen. The cephalothoracic segment is comparatively
small and not distinctly divided into a cephalic and a thoracic part. Between the
lateral processes of the thoracic joints large intervals are to be observed. The oculi-
ferous tubercle is large and high, conical, furnished with four eyes. Of these, two are
very large and directed forwards, while the two directed backwards are a great deal
smaller and in all probability are rudimentary. The abdomen is small, only 1-1 3th
of the total length of the body.

The palpi are slender, and the lengths of their joints are not very characteristic.
The third joint is much longer than the fifth, and of the three last joints the eighth is
very small, the ninth and tenth considerably longer. In the ovigerous legs the fourth
and sixth joints have nearly the same length, while the fifth is not quite half as long.
The four last joints are small, and nearly equal in length, growing however a httle
shorter and more slender towards the tenth joint. The claw is very short.

The distribution and form of the denticulate spines is in this species very charac-
teristic. There are two rows of comparatively long and flat spines, the margins of which
show when greatly magnified very minute hairs ; in addition to these two rows a
moderate number of smaller flattened spines are found scattered over that side of the
four last joints which is bent inwards. I have figured these two rows and the ii-regu-
larly placed spines in figure 3 on Plate IX.

The legs are not very long, nearly three times as long as the body in the
adult specimen, while the younger specimens have them much shorter. The
three first joints are very short, the fourth is the longest, viz., 23 mm.; in a leg, the
fifth joint of which measures 21 mm., the sixth is 18 mm. The two tarsal joints
are together as long as the sixth joint. The claw is large, almost as long as the second
tarsal joint.

The surface of the body and of the legs is almost entirely smooth. The palpi
show only very small haii"s, and on the ovigerous legs hardly any hairs are to be
observed.

Of this species seven specimens were dredged. They are, I think, all young ones
with the exception of one specimen which is a male. It shows genital pores ventrally
on the second joint of aU the legs.

REPORT ON THE PYCNOGONIDA. 69

Habitat. — This specimen was dredged at the following stations : —

Station 149. January 29, 1874. Oflf Christmas Harbour, Kerguelen. Depth of
the sea, 120 fathoms.

Station 313. January 20, 1876. Lat. 52° 20' S., long. 68° 0' W. Depth of the
sea, 55 fathoms. Temperature of the bottom, 8-8° C. Bottom of the sea, sand.

Station 314. January 21, 1876. Lat. 51° 36' S., long. 65° 40' W. Depth of the
sea, 70 fathoms. Temperature of the bottom, 7-8° C. Bottom of the sea, sand.

Observations. — This species resembles Colossendeis proboscidea, Sab., sp. (Appendix to
the Supplement of Captain Parry's Arctic Voyage, 1824, p. ccxxvi.), in the form of the
prol)oscis. That species, however, is a great deal stouter, and has a much larger
body mth comparatively short legs. Moreover, the body of Colossendeis ])wboscidea
is rather disc-shaped, and by no means so slender as that of Colossendeis megalonyx.
This species ranges from Kerguelen as far west as the east coast of Patagonia ; the
three stations, however, at which it was found are nearly under the 50 th parallel.

Colossendeis gracilis, n. sp. (PI. IX. figs. 6-8 ; PI. X. figs. G, 7).

Diagnosis. — Body slender, with wide intervals between the lateral processes ; pro-
boscis about as long as the trunk ; palpus once and a half as long as the proboscis, with
the third joint longer than the fifth, the eighth joint extremely small, and the ninth
joint laterally inserted on the front of the foregoing. Ovigerous legs about once and
a half as long as the total length of the body. The claw of the legs longer than the
second tarsal joint. Oculiferous tubercle conical, without eyes.

Description. —

Length of the proboscis, . . • . . 6-5 mm. 5-8 mm.

Length of the trunk,

Length of the abdomen,

Total length of the body,

Length of the palpus.

Length of the ovigerous leg, .

Length of the leg of the third pair,

The proboscis of this species is nearly as long as the trunk, and a little shorter than
the trunk with the abdomen. It is a little swollen nearly in the middle, but in some
specimens it is almost quite cylindrical. The cephalothoracic segment has the cephalic
part, which is rather triangular, in some degree distinct. It bears anteriorly the very
high conical oculiferous tubercle.

The lateral processes for the insertion of the legs are widely separated. The abdomen
is not very short, and in one of the specimens is a little more swollen at the extremity
than in the others.

Mandibles (PI. X. fig. 6) are present in one of the specimens. It is a young male :

6

)»

5-2

1-5

))

1

14

))

12

9-5

M

9

22

)J

19-5

51

n

40

70 THE VOYAGE OF H.M.S. CHALLENGER.

the largest specimen, however, of this species dredged. These mandibles are very long
and slender, three-jointed, little shorter than the proboscis. The third joint terminates
in a pair of small and slender pincers.

Of the palpi the third joint is longer than the fifth. Of the last three joints the
first is extremely small and broad (PL IX. fig. 7), and the ninth is inserted, not into
tlie middle of the front part of that joint, but quite laterally. This ninth joint itself
is cylindrical, and more than twice as long as the foregoing, whereas the tenth is a little
more slender and still longer than the ninth joint.

The joints of the comparatively long ovigerous legs have characteristic proportions
in all the species of the genus Colossendeis. The claw at the end of the tenth joint
is very small. The denticulate spines on the last four joints are not numerous, the
number of rows not exceeding four. Of these two are very regular, with the spines
placed close to one another, but those of the two other rows are much more irregularly
scattered over the remaining part of the inner surface of the joint (PI. IX. fig. 8 ;
PI. X. fig. 7).

The lengths of the several legs of one and the same specimen only show slight
differences. The third leg is, in the three specimens I have examined, the longest, and
measures nearly three and a half times the length of the body. The claw is very long,
still longer than the second tarsal joint. Genital pores are present on the second joint
of every leg. As to the sex of the three specimens dredged during the voyage of
H.M.S. Challenger, I have only been able to ascertain that the specimen with mandibles
is a male.

The body and legs are almost entirely smooth ; small hairs are only to be observed
on the last joints of the palpi.

Habitat. — This species was dredged between the Cape of Good Hope and Kerguelen
Island.

Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E. Depth of the
sea, 1375 fathoms. Temperature of the bottom, 1-5° C. Bottom of the sea, globigerina
ooze.

Station 147. December, 30, 1873. Lat. 46° 16' S., long. 48° 27' E. Depth, 1600
fathoms. Bottom temperature, 0-8° C. Bottom of the sea, globigerina ooze.

Observations. — To this species Colossendeis media and Colossendeis brevij^es, which
I shall describe further on, are closely allied. The occurrence of mandibles in one of
the specimens of this species is very interesting. Although larvae of any species of
Colossendeis have never been observed, they doubtless are furnished with three pairs of
cephalic appendages. Of these the adult animal has always lost the first pair- ; and
whenever, as in the case in question, this first pair is observed in the adult animal, it
must be considered as a case of atavism, showing that the loss of mandibles in the
adult animal has been comparatively recent.

EEPORT ON THE PYCNOGONIDA.

71

Colossendeis media, n. sp. (PI. X. figs. 10, 11).

Diagnosis. — Palpi more than once and a half the length of the proljoscis ; ninth joint
not attached laterally to the eighth ; together they are as long as the tenth joint.
Denticulate spines of the four last joints of the ovigerous legs in five distinct rows.
Legs not quite three times as long as the body. Otherwise this species resembles the
foregoing.

Description. —

Length of the proboscis, .
Length of the trunk,
Length of the abdomen, .
Total length of the body, .
Length of the palpus.
Length of the ovigorons leg,
Length of the leg of the third pair.

n

mm

H

n

151

12

iO

45 i

This species is nearly of the same shape and the several parts show almost the same
proportions as in Colossendeis gracilis, Hoek. The only differences are the follow-

ing :-

1. The palpi are longer, and of the three last joints the very small eighth joint does
not bear the following joint laterally, but quite in front (PI. X. fig. 10).

2. The denticulate spines of the ovigerous legs (of the four last joints) are placed in
five distinct rows. They are small with the exception of those of the outermost row,
which are a great deal larger. These spines have the flattened shape of those of other
species of Colossendeis. Those which are not broken, show on the margin very small
hairs.

3. The legs are not quite thrice as long as the body, The fourth joint is twice as
long as the sixth. The claw is longer than the second tarsal joint. The two tarsal joints
are about the same length, together they are as long as the body.

The body and legs are almost entirely smooth ; when seen with the microscope very
short hairs are to be observed ; those on the palpi are a little stronger. On the second
joint, on the ventral surface, of every leg very small genital pores are to be observed.
However, as the two specimens of this species probably are not quite adult, I could not
determine to which sex they belong.

Habitat. — This species was dredged at Station 298. November 17, 1875. Lat.
34° 7' S., long. 73° 56' W. Depth of the sea, 2225 fathoms. Bottom temperature, 1-3° C.
Bottom of the sea, grey mud.

Observations. — This species is nearly allied to Colossendeis gracilis. However, as the
differences I have pointed out are present equally in both specimens I cannot consider
them identical with that species.

72

THE VOYAGE OF H.M.S. CHALLENGER.

9

mm.

8-5

mm

7

5

7-5

2

5

2

19

18

12

11-5

29

25

50

54

62

77

53

62

45

52-5

Colossendeis hrevipes, n. sp. (PI. X. figs. 8, 9).

Diagnosis. — Lateral processes not very widely separated. Palpus less than once and
a half as long as the proboscis, with the three last joints bent over like a hook. Ovigerous
legs with the denticulate spines of the four last joints numerous and comparatively short.
Length of the legs unequal, short. Otherwise this species resembles Colossendeis gracilis,
Hoek.

Description. —

Length of the proboscis,
Length of the trunk.
Length of the abdomen.
Total length of tlie body.
Length of the palpus,
Length of the ovigerous leg,
Length of the leg of tlie first pair.
Length of the leg of the second pair,
Length of the leg of the tliird pair.
Length of the leg of the fourth pair,

This true deep-sea species is also nearly allied to Colossendeis gracilis. The first time I
examined it I was struck with the shortness of the legs, especially in the largest specimen ;
but as it is possible that this length varies greatly imder diff"erent circumstances — as it
certainly does with age— it is necessary to use the utmost care in judging of this charac-
teristic mark. The body, proboscis, trunk, and abdomen are as in Colossendeis gracilis,
the only difference being that the lateral processes are not quite so widely separated.

The palpus is short, only one-fourth as long as the proboscis. The last tliree joints
are extremely short, shorter than the seventh joint ; they are bent like a hook, the tenth
joint hanging down parallel with the seventh joint (fig. 8).

The ovigerous legs are comparatively long, 29 mm. in a specimen of 19 mm. The
last four joints are small and furnished with a rudimentary claw, the length of which is
nearly one-fifth the length of the tenth joint. A drawing of the denticulate spines on
one of the four last joints of the ovigerous leg is given in fig. 9. The spines are short
and flat and do not show small hairs at the periphery. There are two regular rows, the
outermost of which has the stoutest and longest spines, whereas the irregularly placed
spines on the other side decrease in size. The length of the legs is very unequal. The
specimen with the shortest legs is a full-grown female. The claw at the end of the
eighth joint is very long, longer than that joint. The Ijody and legs are almost entirely
smooth ; there are small hairs on the last joints of the palpi.

The genital pores of both specimens, the largest of which is a female, are found
ventrally on the second joint of all the legs.

Habitat. — This species was dredged from the greatest depth at which a Pycnogonid
has been found, viz., 2650 fathoms.

REPORT ON THE PYCNOGONIDA.

73

Station 325. March 2, 1876. Lat. 36° 44' S., long. 46° 16' W. Depth of the sea,
2650 fathoms. Bottom temperature, 70-4° C. Bottom of the sea, grey mud.

Observations. — Whether I am right or not in considering the specimens collected at
Stations 146 and 147 {Colossendeis gracilis, Hoek), Station 298 {Colossendeis media,
Hoek), and Station 325 {Colossendeis hrevijies), as three diiferent species can only be ascer-
tained by examining a larger number of specimens than are at my disposal. I can only
point out here the great affinity of these different specimens. However, I may be per-
mitted to state here, that whenever I speak of a specimen as adult, the statement is
based on the microscopical examination of transverse sections of the fourth joint of one
of the legs.

Colossendeis minuta, n. sp. (PI. X. figs. 12-14).

Diagnosis. — Proboscis cylindrical, once and a half the length of the trunk with
the abdomen. Lateral processes not widely separated. Palpus once and a half as
long as the proboscis, with the last three joints of about the same length. Legs
extremely slender, about four and a half times the length of the body. Claw of the leg
half as long as the second tarsal joint.

Description. —

Lengtli of the proboscis, ....

4'8 mm

Length of the trunk,

2-7 „

Length of the abdomen, ....

0-5 „

Total length of the body, ....

8 „

Length of the palpus, ....

7-5 „

Length of the ovigerous leg,

14 „

Length' of the leg of the third pair.

35 „

Only a single specimen of this species was dredged. It is a small animal with a
comparatively long proboscis and very slender legs. The body is not extremely slender,
there being only small intervals between the lateral processes for the insertion of the
legs. The cephalothoracic segment is small and not distinctly divided into a cephalic
and a thoracic part. Quite near the front it is furnished with a blunt oculiferous
tubercle without eyes.

The proboscis is nearly cylindrical, it is a little swollen in the middle, and the mouth
is small and triangular. The abdomen is small ; it is connected with the last thoracic
joint by a true articulation.

The palpus is slender, but not extremely long, being only once and a fourth as long as
the proboscis. The third joint is only a little longer than the fifth. I have given a
drawing of joints six to ten in fig. 13. The last three joints together are longer than the
seventh ; they are of about the same length, and comparatively slender. Beginning
with the fifth, all the joints are furnished with short but strong hairs, which have the
same shape as those on the legs and o\'igerous legs.

(ZOOL. CHALL. EXP. — PAET X. — 1881.) K 10

74 THE VOYAGE OF H.M.S. CHALLENGER.

The ovigerous legs are of the ordinary form. Only the middle of that part of the
surface of the four last joints which is turned inwards, is furnished with denticulate spines.
Their form is very peculiar, being flattened and much broader towards the extremity
(PI. X. fig. 14). They are not very numerous and are placed in three rows only,
while every row contains about six of them. The margin of the spines is smooth.
The claw of the ovigerous leg is small, and the length of the several joints is as in the
other species of the same genus.

The legs are extremely long and slender. With the exception of some small but
strong hairs, like those of the palpus, they are smooth. The first three joints are small ;
of the three following the first two (the fourth and fifth) are nearly of the same length,
whereas the sixth is considerably shorter, but much longer than the last two joints
together. Of these the first (the first tarsal joint) is about once and a half as long as the
second. The claws at the ends of the legs are about half as long as the second tarsal joint.

About the sex of the only specimen collected I am unable to form an opinion.
Perhaps it is not yet quite adult : extremely small genital pores are to be observed
ventrally on the second joint of every leg.

Habitat. — This interesting little Colossendeis was dredged by the Challenger at

Station 50. May 21, 1873. Lat. 42° 8' N., long. 63° 39' W. Depth of the sea,
1250 fathoms. Temperature of the bottom, 2"8° C. Bottom of the sea, grey ooze.

Observations. — This curious form is intermediate, I believe, between the short-naded
Colossendeis leptorhynchus, with its extremely long proboscis, and the long-nailed Colos-
sendeis gracilis, with the comparatively short proboscis. The difi"erence in length between
the third and the fifth joint, — in Colossendeis leptorhynchus the fifth joint is the longest,
and in Colossendeis gracilis it is the third joint which has the advantage — has almost dis-
appeared in Colossendeis minuta.

The species was dredged about two degrees south of Halifax ; though the Pycnogonids
of the neighbourhood of the coast of New England are comparatively well known, the
occurrence of a species of Colossendeis in those regions has not been recorded as yet.
And this, no doubt, is due to the circumstance that the species in question inhabits deep
water, wliile hitherto only the shallow water inhabitants have been carefully investi-
gated.

Discoarachne, n. gen.

Diagnosis. — Proboscis stout, cylindi-ical, tapering towards the extremity. Mandibles
wanting. Palpi five-jointed. Ovigerous legs not furnished with denticulate spines, ten-
jointed.

Discoarachne brevipes, n. sp. (PI. VII. figs. 8-12).

Diagnosis. — Body disciform, consisting of the true body without any segmentation

KEPORT ON THE PYCNOGOISriDA. 75

and the closely united lateral processes. Legs short with auxiliary claws. Body and
legs smooth, furnished only with very small hairs.
Description. —

Length of the proboscis, ....

• . 2|- mm

Length of the abdomen, ....

li »

Total length of the body, ....

4i „

Length of the palpi, ....

n „

Length of the ovigerous legs,

n „

Length of the legs, .....

7 „

The cephalothoracic joint is closely connected with the three other thoracic joints ;
the lateral processes are short and somewhat triangular, forming in connection with the
body a disciform surface, from which the legs radiate in different directions. The
proboscis is comparatively large, the form cylindrical, tapering towards the extremity.
The oculiferous tubercle, which is small, not very elevated, and furnished with four distinct
eyes, is placed dorsally on the middle of that part of the body, which corresponds with
the cephalothoracic segment.

The palpi are small, measuring about two-thirds the length of the proboscis. The
first and second joints are very short, the third joint is the longest of all, the fourth again
small, the fifth more than twice as long as the fourth, and comparatively slender. The first
two joints are smooth, the third joint is furnished up to the outer margin with three long
spines, and on its inside with three smaller spines, which are curved ; the ventrally
directed surface of the same joint, which contains a large gland, hereafter to be described,
has, near the middle, four extremely small spines. The fourth joint is nearly smooth, the
fifth is armed with very large and numerous spines near the extremity.

The first joint of the ovigerous legs is very small, the second and the third are a little
longer, the fourth and the fifth are the longest, the sixth is short again, the seventh,
eighth, ninth, and tenth are about the same length, and gradually diminish slightly in
breadth. The first five joints are nearly smooth, towards the distal extremity the sixth
shows some short and not very strong spines, whereas the four following joints are
furnished in the same place with much stronger and slightly curved spines. Towards
the end of the tenth joint there are a considerable number of these spines, while a claw
and true denticulate spines are totally wanting.

The first three joints of the legs are small ; of the three following, the middle joint is
the longest. The first tarsal joint is extremely short, the second comparatively long, and
very slender in comparison with the other joints of the legs. The claw is about one-
third the length of the second tarsal joint. The auxiliary claws are comparatively
long, two-thirds the length of the claw. The hairs on the different joints of the legs are
small ; the distal extremity of these joints is, as a rule, furnished with a row of longer
and stronger spines, especially at the end of the sixth joint. The first tarsal joint has

76 THE VOYAGE OF H.M.S. CHALLENGER.

numerous small hairs ou the iuner margin ; the second is armed with three very strong
and broad spines on the inner margin near the base, while longer and much more
slender spines are present on the outer margin.

A single specimen of this species was collected during the cruise of H.M.S. Challenger.
It is a female with eggs in all stages of ovarian development, enclosed in the fourth joint
of the leg. The genital pores I could not distinctly observe, but no doubt they are placed
ventrally near the distal extremity of the second joint of the leg.

Habitat. — This species was found at Seapoint near Cape Town in November 1873.

Observations. — The genus Discoaraclme is in all probability nearly allied to Endeis,
Philippi. But as that genus is difficult to make out from the insufficient description
of Philippi, I propose a new genus for the species in question, because Philippi's form
had eight-jointed palpi, whereas the Challenger form, which must be a full-grown animal,
has only five-jointed palpi. This species with its short legs and highly concentrated body,
is a true littoral form.

Palleiie, Johnston.

Pallene australiensis, u. sp. (PI. XL figs. 1-7).

Diagnosis. — Body extremely slender. Cephahc part of the eephalothoracic segment
distinctly separated from the thoracic part by means of a true articulation. Proboscis
short, inserted ventrally. Ovigerous legs with true denticulate spines, and a long
denticulate claw. Legs without auxiliary claws.

Description. —

Length of the proboscis, . . . . • . • 1'5 mm.

Total length of the body, . . . . . . . 6-5 „

Length of the ovigerous legs, . . . ■ • ■ 7 ,,

Length of the leg of the third pair, . . . . . 28 „

The body is extremely slender; the cephalic part of the eephalothoracic segment
(neck) is much swollen at the tip for the insertion of the mandibles. A true articula-
tion divides this cephahc part from the thoracic part. The rather short oculiferous tubercle
is situated about the front of the thoracic part.

The intervals between the lateral processes, at the extremities of which the legs are
found, are very large. The abdomen is rudimentary and directed a little upwards. The
surface of the body and of the lateral processes is smooth. The jDroboscis is short and
inserted rather ventrally. It is constricted beyond the middle, and is much wider at the
extremity, where the very small triangular mouth is observed.

The mandibles are short and robust. The first joint reaches almost as far as the end
of the proboscis, the second joint is considerably swollen, and terminates in a pair of
short pincers. These are furnished with a single very small tooth towards the ex-
tremity.

REPORT ON THE PYCNOGONTDA. 77

The ovigerous legs are inserted ventrally close to the lateral process of the first pair
of legs. Of the first three joints, which are small, the thii-d is the longest ; the fourth
is a great deal longer, and the fifth is the longest of all, in the males it has a
strong knob near the extremity ; the sixth joint is almost as long as the fourth. The
four last joints show no great difference ; from the seventh to the tenth they
gradually diminish in length and in breadth. The claw is as long as the tenth joint,
and on the inside is furnished with a row of small spines. The hairs on the joints
of the ovigerous legs are not very strong. I have figured the denticulated spines in
PI. XL fig. 5.

The legs are very long. The second joint is thrice as long as the fii'st and as the third.
In the female it is considerably swollen towards the extremity, where the genital
opening is observed on the ventral surface. Of the three following joints the fourth
and the fifth are nearly of the same length, whUe the sixth is almost once and a half as
long. The first tarsal joint is extremely short, and the second about eight times as long.
The claw is half as long as the second tarsal joint. The joints of the leg are furnished
with extremely long and slender spines ; two are placed at the distal extremity of the
first joint, two in the middle of the second joint, and two others towards the extremity
of that joint ; a row of slightly shorter ones is observed on the dorsal surface towards
the extremity of the third joint ; the fourth, fifth, and sixth joints are also furnished with
some of these hairs placed at irregular distances from one another ; towards the extremity
of these joints a certain number of these hairs is invariably observed. The first tarsal
joint (fig. 6) shows only a few very short spines, whereas the second tarsal joint
towards the side opposite to the claw is furnished with a complete row of very stout
spines. Most of these spines, like the greater part of those placed on the other joints,
are not quite smooth, but are furnished on one side with sharp short triangular hooks
not unlike the teeth of a saw.

Of the three specimens of this species, one is a female, and two are males. I believe
they are all full-grown animals. One of the males shows the remains of egg-jsackets adher-
ing to the ovigerous legs. The genital openings of the females are much larger than
those of the males. Both sexes have them placed ventrally on the second joint of all
the legs.

Habitat. — This beautiful species was dredged in the neighbourhood of Melbourne.

Station 162. April 2, 1874. Ofi" East Moncoeur Island, Bass Strait. Depth of the
sea, 38 to 40 fathoms. Bottom of the sea, sand.

Also between Melbourne and Sidney at Station 163. April 4, 1874. Lat. 36° 56' S.,
long. 150° 30' E. Trawled in 120 fathoms. Ofi" Twofold Bay.

Observations. — Perhaps this species is nearly allied to Pallene chiragra, MUne-
Edwards, Histoire naturelle des Crustacds, torn. iii. p. 535. He gives the following descrip-
tion of this species : — " Corps trfes-grele ; tete courte mais cylindrique. Second article

78

THE VOYAGE OF H.M.S. CHALLENGER.

des pates-machoires tres-renfl6, et premier article du thorax extremement aEong6. Pates
environ cinq fois aussi longues que le corps, sans crochets accessoires au bout. Pates
accessoires de la femelle de dix articles." However, as in this description the very-
distinct spines on the legs have not been mentioned, which, if present, would certainly
have been seen by Milne-Edwards, I think it probable that his Pallene chiragra is a
nearly allied but distinct species. Jarvis Bay, New Holland, where Mibie-Edwards's
species was collected, is not far from Station 163.

1 mm

2-66,,

5-0 „

4 „

6 „

21-5 „

Pallene Icevis, n. sp. (PI. XL figs. 8-12).

Diagnosis, — Body robust, lateral processes scarcely separated. Body and legs smooth.
Proboscis short, conical ; inserted about the front of the cephalothoracic segment. Ovi-
gerous legs with denticulate spines and a long claw. Legs without auxiliary claws.

Description. —

Length of the proboscis,
Length of the trunk,
Length of the abdomen.
Total length of the body,
Length of the ovigerous leg.
Length of the leg of the third pair,

The body of this species is robust. The cephalothoracic segment is of a curious
shape : it is considerably swollen at the front, where it bears the proboscis and the
mandibles ; it is constricted in the middle, thus forming a sort of short neck, and it is
much wider again at the back, where it bears dorsally the oculiferous tubercle, and
ventrally the short lateral processes for the insertion of the ovigerous legs. The
ocuhferous tubercle, with two larger eyes directed forwards and two smaller ones back-
wards, is situated almost exactly above the insertion of the ovigerous legs. The
lateral processes for the insertion of the legs are comparatively long ; the abdomen is
short and stout.

The proboscis is short and conical, and has a very small mouth at the extremity. The
mandibles are rather stout. The basal joint is constricted at the base, and indistinctly
divided into two joints, it is nearly as long as the proboscis ; the second joint is placed at
right angles with the basal joint, and is considerably swollen and stout. At the
extremity it is furnished with two claws, one straight, pointed and immovable, the other
curved and movable, but also pointed. The inner surface of these claws is smooth, but
there is a blunt point in the middle of the movable claw.

The ovigerous legs of the female specimen (the only one dredged) are not very
strong. The first three joints are small, the fourth and the fifth are the longest, nearly
of the same length and a little curved. The sixth joint is not quite half as long as the
fifth. The four last joints are but little shorter than the sixth. This claw is compar-

REPORT ON THE PYCNOGONIDA.

79

atively strong : it is not denticulated on the inner surface but slightly serrated. The joints
of the ovigerous legs are almost quite smooth. The shape of the denticulate spines is
very curious. They are broad and flat, have two or three stronger teeth on each side
near the base, and extremely fine teeth all over the rest.

The very smooth legs are comparatively long. The first and the third joints are short and
almost of equal length, the second joint is more than twice as long, having a large oval
genital opening at the extremity on the ventral surface. The fourth joint, containing the
ovary, is considerably swollen and very long ; the fifth is only a little shorter, the sixth,
on the contrary, is a little longer. The two tarsal joints are very small, together about one-
fifth of the length of the sixth joint. Almost every joint describes a feeble but character-
istic curve ; especially the second, the fourth and the eighth joint. The first tarsal joint
is extremely small, and is furnished with a large number of hairs and an isolated stronger
spine, the second tarsal joint also shows a number of hairs and four stronger spines
opposite to the claw. The claw is strong and very long, considerably curved, and with-
out auxiliary claws.

The only specimen of this species dredged during the cruise of H.M.S. Challenger
is a female, which, I think, is a full-grown one.

Habitat. — This species, along with a specimen of Pallene australiensis, Hoek, was
collected at Station 162. April 2, 1874. Off East Moncoeur Islaijd, Bass Strait. Depth
of the sea, 38 to 40 fathoms. Bottom of the sea, sand.

Observations. — This very characteristic species may be easdy recognised among the
different species of Pallene by the form of the proboscis and cephalothoracic segment, by
the shape of the denticulate spines of the ovigerous legs, by the presence of a claw at the
end of the ovigerous leg, and finally by the absence of auxiliary claws at the end of
the legs.

Pallene languida, n. sp. (PI. XII. figs. 1-5).

Diagnosis. — Body highly concentrated, rather disciform. Proboscis conical,
cephalothoracic segment comparatively long. Ovigerous legs with denticulated spines,
but without a claw. Legs without auxiliary claws. Oculiferous tubercle conical, elevated.
Rudiments of palpi in the form of knobs.

Description. —

Length of the proboscis,
Length of the trunk,
Total length of the body,
Length of the ovigerous leg,
Length of the leg of tlie third jjair.

0'45 mm.
1-35 „
1-8 „
2-3 „
5-1 „

Of this curious species, unfortunately, only a single specimen was collected, and this
specimen had, moreover, sufiered much from the alcohol ; it is visibly crumpled,^especially

80 THE VOYAGE OF H.M.S. CHALLENGER.

' on the cephalothoracic segment, as seen from the dorsal side ; the other segments have
also suffered in a less degree, which makes it very diflficult to judge of the original form.

The proboscis is small, obtusely conical ; the mouth is small, as in the other species
of this genus. The cephalothoracic segment is considerably swollen anteriorly, where
it bears the proboscis and the mandibles ; in the middle it is constricted so as to form
a neck, and posteriorly it becomes wider again. This wider part (the thoracic part
of the cephalothorax) bears the conical oculiferous tubercle, which shows only rudi-
mentary eyes. The cephalothoracic segment seems, like the two following segments, to
get considerably wider posteriorly on the dorsal surface, thus forming large folds in the
breadth above the insertion of the fii'st three pairs of legs. The fourth thoracic segment
is quite flat ; the lateral processes for the insertion of the legs are extremely short. The
abdomen is very small but comparatively broad.

The surface of the body is smooth ; on the mandibles, the ovigerous legs, and the legs,
numerous not very long but spiny hairs are observed. The first joint of the mandibles
reaches as far as the tip of the proboscis. The second joint is not very strong, is furnished
with slender pincers, and is armed on the inner side with four short teeth. Eudiments of
palpi are implanted ventrally near the base of the mandibles ; they are only one-jointed
knobs.

The ovigerous legs .are short, little longer than the body. The first three joints are
short; the two following joints are much longer ; the fifth is the longest and is armed near
the distal extremity with a small knob; the sixth joint is short. Of the four following
joints the first is the longest, the last three are nearly of the same length. There is no
claw at the end of the tenth joint. . The denticulate spines of one and the same joint
are by no means all of the same shape, those placed near the preceding joint are a great
deal smaller than those in the middle of the row, whereas those placed at the end of the
row are the largest of all, and are furnished at the base with three strong teeth of which
the third especially is very large (fig. 5).

The length of the legs is almost three times the length of the body. The fh'st three
joints are small ; the three following are much longer, but not very slender. The seventh
joint is extremely short ; the second tarsal joint is nearly six times as long. Besides the hairy
spines on all the joints, which, as far as I could ascertain, are scattered rather irregularly over
the surface, the last joint has, on the inner side, a row of short and comparatively strong
spines. The claw at the end of the leg is long and stout. Auxiliary claws are wanting.
Of this species only a single specimen was obtained during the cruise of the Challenger,
and, judging from the knobs at the end of the fifth joint of the ovigerous leg, I consider
it to be a male.

Habitat. — Pallene languida was dredged at

Station 161. April 1, 1874. Off the entrance to Port PhiUp (Melbourne, Australia).
Depth of the sea, 38 fathoms. Bottom of the sea, sand.

. REPORT ON THE PYCNOGONIDA, 81

Observations. — This species is in all probabilitj- nearly allied to Pcdiene longiceps,
Bohm (Sitzungsberichte der Gesellsch. Naturf. Freunde in Berlin, 1879, p. 59). However,
as no figure of Bdhm's species has ever been published, and as the description of it
cannot be entirely applied to my specimen, I thought it safer to consider, and to describe
this as a new species.

Pallene longiceps, Bohm, has rudimentary two-jointed palpi, and a short and blunt
oculiferous tubercle. Moreover, the form of the denticulated spines of the ovigerous
legs of the present species is different from the form described by Bohm for his Pallene
longiceps. The latter species is from Japan, whereas my Pallene languida was obtained
in the vicinity of Melbourne.

PhoxicMlidium, Milne-Edwards.
Phoxichilidium Jluminense, Kroyer (PI. XIV. figs. 1-4).

Phoxichilidium fiuminense, Kroyer, Bidrag til Kundskab, &c., Naturli. Tidskr. Ny Eaekke, vol. i.

p. 124, 1845, Tab. i. fig. \n-f.
Pallene jluminensis, Kroyer (sp.), Bohm, Pycnogoniden des Mnseiims zu Berlin, !Monatsbericht

der k. A. der Wissenscb. zu Berlin, Februar 1879, ]>. 180, Taf. i. fig. 4-4/

This species has been described and figured by Kroyer {lac. cit.), and again by Bohm
{loc. cit.). It may not, however, be considered superfluous to publish new figures ; those
of Kroyer are in general highly characteristic, but they are, as regards the details, not
very exact ; from Bohm's figure, which has been drawn on much too small a scale,
nobody, I think, would recognise the species.

The description given by both authors is nearly correct. The basal joint of the
mandible reaches farther than the tip of the proboscis ; it shows dorsally a little
beyond the middle a slight angle, furnished with a row of stronger hairs : therefore
the joint seen from the dorsal surface seems to be divided into two. Eudiments
of palpi are present in the form of rounded knobs on both sides of the cephalic
segment. The ovigerous legs of the full-grown animal are ten-jointed ; I have figured
joints six to ten in fig. 3. The sixth joint shows a wreath of short strong sjjines imme-
diately before the articulation with the seventh joint. The seventh to the tenth joints are
armed with curved spines and strong hairs, but no denticulate spines at all are present.
These last five joints of the ovigerous leg are very curiously bent in the form of an S, as
has been correctly observed and drawn by Kroyer. The legs are comparatively stout. The
only specimen of this species brought home by the Challenger is a male, with rounded,
rather large genital openings, which, as far as I could ascertain, are present only on the
ventral surface of the second joint of the two hindermost legs. The fourth joint of the
leg is more than twice as long as the second, and not inconsiderably swollen in the
Challenger specimen ; ventrally a little in front of the middle it is furnished with a
distinct and comparatively strong tubular process, which in all probability communicates

(ZOOL. CHALL. EXP. — PAET X. — 1881.) Kll

82 THE VOYAGE OF H.M.S. CHALLENGER.

with a gland situated in the interior ot the joint. This tubular process has been observed
neither by Kroyer nor by Bohm. Probably it occurs only in the male sex. The fifth
joint is as long as the fourth, the sixth a little longer. The first tarsal joint is short, the
second comparatively long, armed with a claw and two long auxiliary claws. Joints one
to four have only a few hairs, while joints five to eight are covered by numerous, and
for the most part, comparatively long and stout hairs.

Habitat. — This species, according to Kroyer, is found oft' Eio de Janeiro, whereas
Bohm describes specimens collected by the German man-of-war, the " Gazelle," in the
Straits of Magellan, and on the Patagonian coast, at a depth of 30 to 42 fathoms. One
specimen was dredged by the Challenger off" Bahia. Depth, from 7 to 20 fathoms.

Observations. — Bohm considers this species a Pallene. I think, however, there can
be no doubt that it is a true Phoxichilidiiim in the sense of Kroyer. To take the num-
ber of joints of the ovigerous legs as a decisive proof in this matter is, I think, not
safe. The ovigerous legs of the Pallene [Pallene lappa, Bohm) which Bohm examined,
were only seven-jointed, and for that reason alone the specimen cannot be considered
as a PlioxichHidiiim. Of much greater value, I think, is the form of the ovigerous leg
itself, the form of the last joints, of the spines with which they are furnished, &e., also
the whole form of the body, the manner in which the cephalic part of the cephalothoracic
segment overhangs the proboscis, &c.

xAjiother question is, of course, whether it would not be convenient to class as a separate
genus those forms of Phoxichilidium which have ten-jointed ovigerous legs, probably
always present in both sexes. But before taking this step, the different forms ought to
be better known, and for this a close study of full-grown speciaiens of both sexes is neces-
sary. The genus Anoplodactylus of E. B. Wilson cannot be accepted, because neither
the presence or absence of auxiliary claws, nor the fact of the ovigerous legs being five-
or six-jointed, has any real importance.

Phoxichilidium insigne, n. sp. (PI. XIV. figs. 5-7).

Diagnosis. — Body slender, with large intervals between the lateral processes. Pro-
boscis cylindrical, inserted ventrally far posteriorly between the two ovigerous legs. Man-
dibles two-jointed, the first joint bearing the second laterally. Ovigerous legs six-jointed.
No auxiliary claws. Legs and mandibles furnished with large conical knobs.

Description. —

Lengtli of tlie proboscis, . , , . , , .2 mm.

Total lengtli of the body, . . . . . . . 6 „

Length of the abdomen, . . ... . . . 0-5 „

Length of the ovigerous leg, ...... 4'2 ,,

Length of the leg of the first pair, .. . . . . . 19 „

Of this most curious form, unfortunately, only a single specimen — and that much

. REPORT ON THE PYCNOGONIDA. 8

mutilated, with only five legs — was collected during the voyage of the Challenger. This
specimen is, I think, a full-grown male. The body is extremely slender, with very large
intervals between the lateral processes for the insertion of the legs. The cephalo-
thoracic segment is rather short, about twice as long as the first true thoracic segment ;
the second thoracic segTnent is a little longer than the first, and the third is, again, a little
shoi-ter. The proboscis is long, inserted ventrally, far back between the two ovigerous legs.
It shows a little swelling at its base, in the middle, and again at the extremity. The
mouth is small and triangular. The abdomen is short and directed somewhat upwards.

At the base of the mandil:)les the front part of the cephalothoracic segment is
for a short distance cloven in the middle. Immediately behind this cleft the blunt
oculiferous tubercle, with its four dark eyes, Ls placed. The basal joints of the mandibles
diverge considerably, and extend beyond the front of the proboscis. The end of this basal
joint, which is directed forwards, terminates in a pointed appendage, and laterally, under-
neath the end of this appendage, the short second joint is attached. This has the form
of a bird's head with the small pincers as jaws. The inner surface of these pincers is
smooth. The first joint towards its extremity and the whole surface of the second joint
are covered with numerous long hairs.

The ovigerous legs are inserted close to the base of the proboscis; they are six-jointed;
the first joint is small, the second about half as long as the proboscis, the third nearly as
long as the proboscis, the fourth half as long as the second, the fifth a little shorter than
the fourth, and the sixth extremely small. All the joints are furnished with numerous
small hairs ; those on the two last joints are a little longer, but still extremely slender.

The first joint of the legs is small, nearly as long as the lateral process, the second joint
is more than twice as long as the first, the third joint nearly half as long-as the second,
the fourth is as long as the trunk with the abdomen, the fifth is but little shorter, the
sixth is as long as the whole length of the body, the seventh is short, and the eighth
nearly as long as the second joint. The part of the eighth joint facing the strong claw
has a distinct shoulder, furnished with spines and small hairs. The first joint of the
leg bears at the distal extremity, on both sides, a strong conical protuberance ; the second
bears a still larger one ventrally, and another at the distal extremity ; the third, too,
is furnished with one. Besides three strong protuberances at the distal extremity, the
longest of which is placed between the two others, the fourth joint has three other
protuberances placed laterally on the joint ; one of these is placed in the middle, the two
others on the other side at ec[ual distances from the middle one. The protuberances at
the extremity of the joint are much larger than the others found on the joint. The
latter have, moreover, a slender spine at the top. The armature of the fifth joint is
nearly the same as that of the fourth. The sixth joint is furnished with numerous small
protuberances, bearing slender spines at the top. Distinct hairs are seen on all the
joints ; towards the fourth joint they grow stronger and denser. The sid.e of the last

84 THE VOYAGE OF H.M.S. CHALLENGER.

joint facing the claw when it is closed is furnished, in addition to numerous slender
spines, with a row of curiously-shaped teeth (see fig. 7 of PL XIV.). The last joint
terminates in a strong protuberance, like those placed at the extremities of the other
joints of the leg. The claw is long and stout ; auxiliary claws are wanting.

I think the only specimen of this species dredged by H.M.S. Challenger is a male.
I could not, however, ascertain the sex without injuring the specimen, and I can only
state my supposition. It is based on the fact that there are species of PhoxicMlidium
in which six-jointed ovigerous legs are present only in the male, and also on the pre-
sence of dermal glands in the fourth joint of the leg.

Habitat. — This curiously-shaped Pycuogonid was dredged off Bahia at a depth of 7
to 20 fathoms.

Observations, — I think this species of PhoxicMlidium is a near relation of the European
shore and shallow- water forms of the same genus {Phoxichilidium femoratum, P. virescens,
&c.) ; from these it can be easily distinguished by the extremely characteristic protuber-
ances on the legs, mandibles, &c.

Phoxichilidium jmtagonicum, n. sp. (PL XII. figs. 6-9).

Diagnosis. — Body robust, lateral processes scarcely separated. Basal joint of the
mandibles indistinctly divided into two joints, second joint short, with small pincers.
Palpi represented by large rounded knobs. Ovigerous legs ten-jointed, without claws,
present in both sexes ; auxiliary claws on the legs. Abdomen long.

Description. — Of this species a full-grown female and two small specimens, about
whose sex I do not feel quite sure, were dredged by H.M.S. Challenger. For the
description I have made use of the full-grown female.

Length of tlie ijroboscis.
Total length of the body.
Length of the ahdomen,
Length of the ovigerous legs.
Length of the leg of the thu-d paii-.

6 mm.
16 „

5 „
11 »
57 „

The body of this species is almost entirely smooth ; the cephalothoracic segment,
which is not quite so long as the abdomen, bears the oculiferous tubercle quite at the
front. The two follomng thoracic segments are together not quite so long as the cephalo-
thoracic segment. The last segment is very small, it bears a long abdomen directed
upwards. The length of the lateral processes is very considerable.

The proboscis is ventrally inserted, its base is found considerably behind the front
margin of the cephalothoracic segment. It is comparatively long, and its shape is cylin-
drical ; the extremity is rounded, with a small triangular mouth.

The mandibles are inserted close to each other and have a very long basal joint.

REPORT ON THE PYCNOGONIDA. 85

which, seen from the dorsal side about the middle, shows a distinct articulation. This
basal joint is considerably swoUen at the extremity ; the second joint is dii'ected towards
the ventral side, while its pincers are bent laterally, so as to be directed towards those of
the other mandible. These pincers are smooth and extremely short. While the basal
joint of the mandibles is nearly smooth, the second joint is furnished with numerous and
strong hairs, which are a little stronger still at the base of the pincers.

The palpi are represented by large rounded tubercles, placed at both sides of the
base of the proboscis.

The ovigerous legs are comparatively short (at least in the female). The first joint
is very small, the second is elongated and not quite three times as long as the first, the
thii-d is again short, the fourth and fifth joints are longer, the sixth is only two-thirds the
length of the fifth, and the last four joints are small. They are figured on Plate XII. fig. 8,
and are covered with long spiny hairs. There is no claw at the end of the tenth joint.

The first joint of the legs is small, the second is more than twice as long, and be-
comes considerably thicker towards the extremity, the third joint is only a little longer
than the first, the three following are about the same length ; the fifth joint, however^is
the smallest, the sixth the longest. This joint in the second leg of the right side describes
a slight curve, which -at the convex side is surmounted by a strong conical protuber-
ance. I think, however, tJiere can be little doubt that this conical protuberance is to be
considered as an accidental outgrowth caused probably by the joint having been broken
and afterwards healed. The first tarsal joint is very short, and the second is about as long
as the second joint of the leg. At its extremity the last joint bears a comparatively
feeble claw and two auxiliary claws. The joints of the legs have numerous but small
and stout hairs ; they are at the swollen extremity of the second joint, and on the third
and the fourth joints ; on the following joints they are much more numerous, but also
a great deal more slender. On the two last joints, which have also stronger spines, for
example on the side facing the claw, they are most numerous of all.

The female specimen shows very large genital pores at the considerably swollen distal
extremity of the second joint of the leg. They are found ventrally on all the legs. The
specimens seem to be very brittle, especially the younger ones, which had lost nearly all
their legs.

Hahitat.—This species was coUected at three difierent stations not far from the coast
of Patagonia.

Station 304. December 31, 1875. Lat. 46° 53' S., long. 75° 11' W. Depth of the
sea, 45 fathoms. Bottom of the sea, sand.

Station 308. January 5, 1876. Lat. 50° 10' S., long. 74° 42' W. Depth of the
sea, 175 fathoms. Bottom of the sea, mud.

Station 313. January 20, 1876. Lat. 52° 20' S., long. 68° 0 W. Depth of the
sea, 55 fathoms. Temperature at the bottom, 8-8° C. Bottom of the sea, sand.

3-5

mm

9-5

)»

2-5

))

28-5

j»

4

))

86 THE VOYAGE OF H.M.S. CHALLENGER.

Observations. — In general, the shape of this Pycnogomcl resembles that of PhoxicMU-
dium digitatum, Bohm. However, in many respects, it may be easily distinguished from
this and other species of PhoxichiUdium hitherto described ; for instance, hj the presence
of ovigerous legs in the female, by the presence of auxiliary claws, by the number of
joints (10) of the ovigerous legs, &c. Like most other species of the same genus, this
species seems only to occur in shallow water (depth 45 to 175 fathoms) not far from the
coast.

Phoxichilidiuin patagonicum, var. elegans, n. var. (PL XII. fig. 10).
Diagnosis. — Like PhoxichiUdium jycitagonicum, Hoek, only much more slender.
Description. —

Length of the proboscis,

Total length of the body, .

Length of the abdomen,

Length of the leg of the third pair, .

Length of the ovigerous leg,

A young specimen has the different thoracic segments by no means so concentrated
or robust as is the case in the specimens of PhoxichiUdium patagonicum ; the lateral
processes are much more widely separated ; in general the length of the body, in com-
parison with that of the legs and of the proboscis, is much more considerable. The oculi-
ferous tubercle is furnished with four eyes, but the two foremost are much larger than
the two others. The length of their legs and their joints is not very different from that of
PhoxichiUdium patagonicum ; the only difference being that the total length is compara-
tively less. The claws and the auxiliary claws are as in PhoxichiUdium patagonicum.
About the sex of this specimen I do not feel Cjuite sure : most probably it is a young female.

Habitat.— Citation 320. February 17, 1876. Lat. 37° 17' S., long. 53° 52' W.
Depth of the sea, 600 fathoms. Bottom temperature, 27° C. Bottom of the sea, hard
ground.

Observations. — The single specimen of this form resembles PhoxichiUdium j^cita-
gonicum so strongly that I hesitated long whether or not I should consider it as
specifically distinct. My study of other species, younger and older specimens, has
convinced me that, as a rule, as the animal advances in age, its slenderness increases.
Now, in the present case, a young specimen shows considerable slenderness, while
the full-grown female is much more concentrated. That it is a young sj)ecimen is proved
by the rudimentary condition of the ovigerous leg. I therefore feel inclined to consider
this form as a variety of my PhoxicJiiUdium patagonicum. Considering the difference
in depth of the stations at which that species and the present form were dredged, we
have here most probablj'- an instance of the influence of surrounding circumstances on the
form of an animal.

REPORT ON THE PYCNOGONIDA. 87

Fhoxichilidium molhssimum, n. sp. (PI. XIII. figs. 6-9),

Diagnosis. — Body robust, lateral processes not very widely separated. Mandibles
distinctly three-jointed, with curved, smooth, and not very long pincers. Ovigerous legs
ten-jointed, without claw (probably present in both sexes). Auxiliary claws (1). Palpi
represented by small rounded protuberances. Legs with silky hairs.

Description. —

Length of the proboscis,

• • • •

9'5 mm

Total length of the body, .

. ■

28 „

Length of the abdomen,

. . .

9 „

Length of the o^•igerous leg,

.

20 „

Length of the first six joints

of the leg.

. 110 „

Of this interesting deep-sea Pyenogonid, unfortunately only a single specimen
(much injured) was collected during the voyage of H.M.S. Challenger. There is not
a single complete leg; and of the incomplete ones, with their three joints, there are in
all only three present. However, this form is so highly characteristic that I think it
possible to give, even from this defective specimen, a description which will be recognised
by future investigators.

The body is robust; like the proboscis, the lateral processes, and the first joints of the
legs, it is entirely smooth. The front of the cephalothoracic segment projects over
the base of the proboscis. This front part bears dorsally the blunt oculiferous tubercle,
with its rudimentary eyes, and quite anteriorly the large mandibles are inserted. These
run parallel to one another, and are distinctly three-jointed. The basal joint is -com-
paratively long, swollen at its base, and again at the extremity ; the second is about
two-thirds the length of the basal joint; the third joint is very short, and terminates in
a pair of smooth, strongly-curved pincers, which, when closed, have a wide interval
•between them.

The proboscis is very stout, swollen a little in the middle, and also at the extremity ;
seen laterally, the swelling at the extremity appears rather stronger on the dorsal than
on the ventral side. The triangular mouth is quite closed by the labial plates-. Near
the base of the proboscis the cephalothoracic segment bears on both sides a small blunt
protuberance, which represents the palpus.

The ovigerous legs are inserted ventrally. Seen from that side, the cephalothoracic
segment is distinctly divided into two segments, and the ovigerous legs originate from
the first of these two segments. They are inserted on small processes, which represent
the lateral processes of the ovigerous legs, and have ten joints. The first and third
joints are short; the second is about twice as long; the fourth is comparatively stout and
longer than the second; the fifth is as long as the second, and much more slender
than the fourth; the sixth is shorter than the fifth* slender, but swollen at the extremity.
The last four joints do not show any great difi"erences in' length; however, from the

88 THE VOYAGE OF H.M.S. CHALLENGER.

sixth to the tenth each joint is more slender than the preceding one. The hairiness of
the different joints of the leg is not very great. Some hairs are found on the second to
the sixth joints, the latter being, esjiecially at the swollen extremity, furnished with
some stronger hairs. The seventh joint is, near the extremity, armed with very long
hairs; the eighth joint has them all over the surface; on the ninth joint the hairs are
short and few; while the very slender tenth joint is furnished not only with some short
hairs, but also with rows of stronger spines.

The lateral processes for the insertion of the legs are comparatively long. The abdo-
men is very long, being nearly cylindrical, and at the extremity a little swollen.

The second joint of the leg is twice as long as the first and the third. Of the three
following joints, which are comparatively long, the first is a little longer than the second,
and a little shorter than the third. With the exception of a row of not very nume-
rous hairs placed at their extremities, the first three joints are smooth; the fourth
shows already a small number of very thin hairs, which are much more numerous on
the fifth, and extremely numerous on the sixth joints. On these last two joints, however,
the hairs cover only half the surface longitudinally, whereas the other half has slender
spines placed in distinct rows (fig. 9).

The single specimen of this species shows ventrally small genital pores on the second
joint of the first, second, and third legs (the only legs present). From the smallness of
these genital pores, the absence of ovaries in the fourth joint of the leg, and the shape of
the ovigerous legs, I conclude that this specimen is a male.

Habitat. — The single specimen was brought up from

Station 237. June 17, 1875. Lat. 34° 37' N., long. 140° 32' E. Depth of the sea,
1875 fathoms. Bottom temperature, 1 "7° C. Bottom of the sea, mud.

Observations. — This species and the two following (Phoxichilidium oscitans, Hoek,
and Phoxichilidium pilosum, Hoek) are nearly allied. They are furnished with ten-
jointed ovigerous legs, present in both sexes, and three-jointed mandibles. The late Dr
E. von Willemoes-Suhm erroneously mentioned these species as belonging to the genus
Zetes, Ki'oyer. When comparing these species with true three- jointed mandil)les,
with Phoxichilidhim flummense, Kroyer, with two-jointed mandibles, and a distinct
row of spines dorsally near the middle, and with Phoxichilidium ^?«fo(70?n'cw7ji,
Hoek, which has the basal joint divided into two when seen from the dorsal surface,
and quite undivided when seen from the ventral surface, it becomes evident that
this division, even when so distinctly developed as is the case with Phoxichilidium
moUissimum, Phoxichilidium oscitans, and Phoxichilidimn pilosum, does not justify
us in considering these species as belonging to a different genus. Even should this
be proposed, they could never be considered as species of Zetes; for that genus
has ten-jointed palpi, whereas these organs in the present forms have become entirely
rudimentary.

REPORT ON THE PYCNOGONIDA.

89

Phoxichilidium oscitans, n. sp. (PI. XIII. figs. 1-5).

Diagnosis. — Body robust, lateral processes not very widely separated. Mandibles
three-jointed, with long and slender pincers. Ovigerous legs ten-jointed, without claws,
probalily present in both sexes. Auxiliary claws present. Palpi represented by rounded
protuberances. Proboscis swollen in the middle, and considerably at the tip.

Description. —

Length of the proboscis, ....

8

Total length of the body, ....

21-5

Length of the abdomen, ....

6-5

Length of the ovigerous leg.

9-6

Length of the leg of the third pair,

97

A single specimen of this beautiful species was brought home by the Challenger. It
is a species with a robust body, with long lateral processes, which are not widely
separated, a very long abdomen, and a very stout proboscis. The first or cephalic part
of the cephalothoracic segment is almost globular, and bears about its middle a blunt
oculiferous tubercle with two rudimentary eyes, represented by brown spots, which are
connected by a slender strip of pigment, the whole not unlike the form of what the
French call a pince-nez. The cephalothoracic segment is nearly as long as the three
other segments together. The abdomen is long, cylindrical, swollen at the extremity.

The proboscis is very stout ; it is considerably swoUen in the middle, and also at the
extremity. This extremity is flattened at the front, and has a very large triangular
mouth, the three lips of which are turned inwards. While the body is almost everywhere
smooth, the front of the proboscis bears round the mouth not very long but compai'atively
strong hairs.

The mandibles are distinctly three-jointed. The first joint is the longest ; the second
is but little shorter ; together they reach considerably beyond the end of the proboscis.
The third joint is small, and bears a pair of extremely slender pincers, the movable one
being much more strongly curved than the immovable one. At the end of the first
joint a row of not very long but comparatively strong hairs is observed ; those at the
extremity and over the whole surface of the third joint are a little longer. The pincers
are quite smooth.

The palpi are represented by very large globular pi'otuberances, placed at both sides,
near the base of the proboscis.

The ovigerous legs are inserted ventrally not far from each other. Seen from the
ventral side, the cephalothoracic segment is much shorter than when observed dorsally ;
nor is there from that side any trace of a division into two joints to be seen, as is the
case in Phoxichilidium mollissimum, Hoek.

The length of the joints of the ovigerous legs is exactly as in Phoxichilidium

(ZOOL. CHALL. EXP. — PART X. — 1881) K 12

90 THE VOYAGE OF H.M.S. CHALLENGER.

mollissimum ; the first and third joints are short, the second is a little longer, the fourth
longest of all and much thicker ; the fifth joint is only a little shorter than the fourth,
but considerably more slender ; the sixth again is a little shorter than the fifth, and
swollen at the distal extremity. The last four joints are short and nearly of equal length.
The hairs on these last joints are not so long, but more regularly spread over the surface,
than is the case in Phoxichilidium mollissimum. The tenth joint, however, shows nearly
the same row of spines and the same short hairs as in the foregoing species.

The legs are very long. The relative length of the joints is the same as in Phoxi-
chilidium mollissimum. The seventh joint is short ; the eighth joint is a little curved.
Both these joints are slender ; together they are nearly equal in length to the second joint
of the leg. The claw is very long, and furnished ■with two small auxiliary claws. That
side of the eighth joint which faces the claw shows a row of stronger spines, the last
of which is considerably longer than the others. Besides distinct rows of stouter hairs
at the extremity of the joints, the number of hairs on the surface of the joints consider-
ably increases from the fourth joint downwards, the greatest number being found on the
distal part of the sixth joint.

The only specimen is probably a male. Its genital openings are small, and are placed
ventrally on the second joint of every leg.

Habitat. — This beautiful deep-sea species was found at

Station 70. June 26, 1873. Lat. 38° 25' N., long. 3.5° 80' W. Depth of the sea,
1675 fathoms. Sea bottom, globigerina ooze.

Observations. — This species is nearly allied to the foregoing {Phoxichilidium mollissi-
mum, Hoek), and also to the following species {Phoxichilidium inlosum, Hoek). It may,
however, be easily distinguished from these species by the form of the proboscis and of
the cephalothoracic segment, and by its extremely long legs.

Phoxichilidium pilosum, n. sp. (PL XIII. fig. 10-13).

Diagnosis. — Body not very robust, lateral processes widely separated. jMandibles
distinctly three-jointed, with small straight pincers. Ovigerous legs ten-jointed, without
claws, present in both sexes. Auxiliary claws present. Palpi represented by rounded
protuberances. Proboscis cylindrical, tapering towards the extremity. Body (dorsally)
and legs covered with extremely long and thin hairs.

Descrii)tion. —

Length of the proboscis,
Length of the abdomen,
Total length of the body,
Length of the ovigerous leg, .
Length of the leg of the third pair,

Of this species three specimens were collected during the cruise of H.M.S. Challenger;

.5

mm

5

)j

1.5

)»

S

»

44

)»

REPORT ON THE PYCNOGONIDA. 91

there are two females and a male. The male is a great deal smaller than the larger of
the two females. I therefore give the description from the larger female. The body
is stout, but, as the lateral processes are widely separated, not very robust. The
cephalothoracic segment is not very long. Quite in front of it the oculiferous tubercle
is inserted so as to overhang the base of the mandiljles. It is much elevated, conical,
with two larger eyes directed forwards, and two smaller ones directed backwards. The
first and second true thoracic segments together are shorter than the cephalothoracic
segment. The last thoracic segment is short, and l^ears at the extremity a very large
abdomen, the length of which is nearly equal to that of the proboscis. The abdomen is
a little swollen at the tip. Dorsally the surface of the body of the lateral processes and
of the aljdomen is furnished with very slender hairs, of which a distinct row is observed
on the hinder margin of the diflferent thoracic segments.

The two mandibles are three-jointed ; the first two joints run parallel to each other.
The first joint reaches as far as the end of the proboscis ; the second joint is a little
longer ; the third is inserted on the second, with which it makes a right angle. The
pincers of the two mandibles are directed horizontally towards each other ; they are placed
at a short distance from the end of the proboscis, are straight, and very short.

The prolwscis is cylincbical, tapering towards the extremity, where the small mouth
is situated. At the base of the proboscis the two protuberances representing the palpi
are inserted.

The ovigerous legs are ten-jointed : the first arid third joints are very small ; the
second is about twice as long ; the fourth and fifth are the longest of all ; the sixth joint
is short ; and of the four last joints the second is the longest and the last the shortest.
They are covered with not very long but thin hairs, rows of stronger ones, as a rule,
being found at the extremity of the joints.

The second joint of the legs is nearly twice as long as the first or thiixl, and in the
female considerably swollen at the extremity. The fourth joint is also consideral^ly
swollen in the female, and is longer than the first three joints together. The fifth
joint is much more slender and also a little shorter than the fourth ; the sixth is much
longer and, at the same time, a gxeat deal more slender. The two last joints together are
not quite one-third the length of the sixth joint. The first tarsal joint is extremely short,
the second al^out five times as long. From the first to the sixth all the joints are covered
with very long and slender hairs, giving an extremely woolly appearance to the whole
animal. The first tarsal joint is furnished with numerous stronger and smaller hairs ; the
second shows a row of distinct spines, the last of which is the largest, while the others
diminish in size. The claw at the end of the leg is very large ; it is accompanied by two
extremely small auxiliary claws.

The females have very large genital openings ventrally on the swollen extremity of the
second joint of all the legs. In the males I could observe the small genital pores only

92 THE VOYAGE OF H.M.S. CHALLENGER.

on the ventral surface of the two hindermost legs. They are here placed at the tip of a
small tubercle, which is likewise absent on the two first pairs of legs. The genital pores
of the males are almost quite covered by the surrounding hairs.

This hairy Pycnogonid was dredged by the Challenger at two different stations.

Station 147. December 30, 1873. Lat. 46° 16' S., long. 48° 27' E. Depth of the
sea, 1600 fathoms. Temperature of the bottom, 0'8° C. Bottom of the sea, globigerina
ooze.

Station 157. March 3, 1874. Lat. 53° 55' S., long. 108° 35' E. Depth of the sea,
1950 fathoms. Bottom of the sea, diatom ooze.

Observations. — The near relation which this beautiful deep-sea species bears to the
two foregoing ones is evident. They form the true deep-sea representatives of the genus
Phoxichilidium, Milne- Edwards, which probably will be found to have an extremely
wide range.

Hannonia, n. gen.

Diagnosis. — Proboscis stout, inserted quite in front of the cephalothoracic segment.
Mandibles rudimentary, small, two-jointed, chelate. Palpi wanting. Ovigerous legs,
present in both sexes, ten-jointed.

Hannonia typica, n. sp. (PL XIV. fig. 8-11).

Diagnosis. — Body robust, proboscis long-ovate, truncated at the tip, and forming a
narrow stalk posteriorly. Legs short, with a small first tarsal joint and a claw, without
auxiliary claws.

Description. —

Length of the proboscis, ....... 4 mm.

Length of the trunk with the abdomen, . . . . . 7 „

Total length of the body, . . . . . . . 11 ,,

Length of the leg of the third pair, . . . . . . 12 „

This curious sea-spider has a robust body ; the cephalothoracic segment is not very
large, and, like the two following segments, its hinder margin is furnished with an
elevated ridge ; on these ridges a row of small hairs is inserted. The oculiferous
tubercle is blunt, and placed in the middle of the cephalothoracic segment. It is
furnished with four comparatively large black-coloured eyes. The dorsal surface of the
lateral processes, like that of the last thoracic segment immediately in front of the inser-
tion of the abdomen, shows rounded protuberances, on the surface of which small hairs —
like those of the ridges on the hinder side of the thoracic segments — are placed.
The abdomen is not very long, but stout and swollen at its extremity. Its surface is
likewise covered with numerous small hairs. The form of the proboscis is ovate ; at the
anterior end it is flattened and truncated. The mouth is found in the middle of this trun-
cated surface ; it is triangular, with comparatively large lips. At the back the proboscis is

REPORT ON THE PYCNOGONIDA. 90

narrower, the narrow part thus forming a sort of stalk-like process on which the ovate
front part is borne. The surface of the proboscis, when seen with the naked eye or
slightly magnified, is entirely smooth.

The mandibles are small and rudimentary ; they consist of a short basal joint and a
quite rudimentary second joint, armed wdth rudimentary pincers. The length of the
mandibles is about one-fourth the length of the proboscis.

The ovigerous legs are not very strong ; they are ten-jointed. The first three joints
are short ; the fourth and the fifth joints are the longest ; the sixth is about two-thirds
the length of the fifth ; and of the last four joints the first is by far the longest, and the
third the shortest. A small claw is found at the extremity of the tenth joint. All the
joints are furnished with small haii-s ; the last four joints are not armed wdth denticulate
spines, but with not very strong straight spines, scattered rather irregularly over the
whole surface of the joints.

The legs are short. The first three joints are extremely short ; the three following
are longer and nearly of the same length, which is shorter than that of the first three
joints together. The first tarsal joint is very short ; the second comparatively long and
feebly curved, it bears at the extremity a small strongly-curved claw, which is sickle-
shaped, and not accompanied by auxiliary claws. All the joints of the legs are furnished
with numerous minute spines, placed in regular rows ; the fifth and sixth joints, however,
are also armed with a distinct row of tubercles, each bearing a small but strong sj^ine at
the tip (fig. 11).

The only specimen of this species .s a female. It has very large genital pores on the
second joints of all the legs. The ovaries are found reaching as far as the sixth joint of
the leg. The ovarian eggs are exceedingly numerous, but comparatively large.

This interesting Pyenogonid was found on the shore at Seapoint, near Capetown.

Observations. — It is a true shore inhabitant, and forms among the species with-
out palpi the transition from those with {Pallene and Phoxichilidiutn) to those
without mandibles {Pycnogonum and Phoxichilus). To the first of the latter genera
(Pyowgonum) it is, I believe, very nearly allied — viz., by the robustness of the body and
by the presence of the protuberances (which I showed in my paper published iu 1877,
Ueber Pycnogoniden, to be outgrowths of the skin, richly armed with tactile organs)
on the dorsal surface of the body and of the lateral processes. The want of auxiliary
claws in both genera is also striking. Distinct cliff"erences are furnished by the presence
of mandibles, and of ovigerous legs in the female of my Hannonia typica ; I have
akeady pointed out above, however, that I do not consider these diifereuces very
important.

94 THE VOYAGE OF H.M.S. CHALLENGER.

APPENDIX I.

DESCRIPTION OF THE SPECIES DREDGED DURING THE CRUISE
OF THE " KNIGHT ERRANT. "

During the recent cruise of the " Knight Errant, " organised by Prof. Sir Wyville
Thomson to acquu-e a more accurate knowledge of the abnormal distribution of tempera-
ture in the Faroe Channel, numerous Pycnogonids were collected by trawling. As this
cruise bears upon the voyage of the Challenger and the study of the results of her
voyage, I was asked to give also a description of these foiins for this report.

Nymphon stromii, Kroyer.

Numjihon stromii, Kroyer, BiJriig til Kundskab, &c., Naturh. Tulskr., N. R., i. Ill, 1845.
Nymphon gracilipes, Heller, Crustaceen, Pycnogoniden, und Tunicaten der K. K. Oester.

Ungar. NordpoL Exped. Denkschr. der Math., Naturw. Classe der Kaiserlichen Akad. der

Wiss., XXXV. 40, 1875.
Nymphon stromii, Kroyer, Miers, Ann and Magazine, 4th series, vol. xx. p. 109, 1877.
Nymphon gracilipes, Heller, G. 0. Sars, Prodromus descriptionis Crustaceorum et Pycnogoni-

darum, (juae in expeditione Norvegica, anno 1876, observavit. Arch. f. Math, og Naturvid.,

ii. 265, 1877.
Nymphon stromii, Kroyer, Wilson, Pycnogonida of New England, Transact. Connect. Acad.,

vol. V. p. 17, pi. vi. fig. la-17i, 1880.

This beautiful and distinct species is accurately described by Kroyer, and also by
Wilson. Its synonymy and wide geographical range I have discussed at some length in
the description of the Pycnogonids collected during the two cruises of the Dutch schooner
" WiUem Barents " in the Barents Sea, which at this moment is in the hands of the
printer, and will be published probably before the end of the year (1880).^

The dimensions of the " Knight Errant " specimens are much smaller than those of
the specimens described by Heller and myself, and even smaller than those which Wilson
has got from the neighbourhood of the North American coast.

The extent- of the largest "Knight Errant" specimen is not quite 100 mm. The

' Supplement-Band of the Niederliindisches Archiv fiir Zoologie, Leiden, E. J. Brill.

' " Extent is the distance from tip to tip of the outstretched legs" (Wilson, loc. cit., p. 5).

REPORT ON THE PYCNOGONIDA. 95

depth from whicli this species was brought up is from 515 to 540 fathoms. The stations
where it was found are the following :—

Station No. 5 (cruise of the "Knight Errant"). Lat. 59° 26' N., long. 7° 19' W.
August 11, 1880. 515 fathoms. Warm area. Two specimens.

Station No. 7 (cruise of the "Knight Errant"). Lat. 59° 36' N., long. T 18' W.
August 12, 1880. 530 fathoms. Warm area. Two specimens.

Station No. 8 (cruise of the "Knight Errant"). Lat. 60° 3' N., long. 5° 51' W.
August 17, 1880. 540 fathoms. Cold area. Ten specimens.

In this animal, therefore, we have an example of one inhabiting the cold and
warm areas on both sides of the ridge rising in the Faroe Channel to within 300 fathoms
of the surface.^ This agrees very well -with the facts of the geographical distribution of
our species ; it is a common inhabitant of the depths of the Arctic Sea, but it is also by
no means rare in the deeper water of southern latitudes, especially in the neighbourhood
of the American coast.

Nymphon grossipes, 0th. Fal^ricius.

Nymp)hon grossipes, 0. Fabricius, Fauna Groenlandica, p. 229, 1780. (See p. 44 of
this report.)

A single specimen of this species, was dredged at

Station 8 (cruise of the " Knight Errant "). Lat. 60° 3' N., long. 5° 51' W. August
17,1880. 540 fathoms. Cold area.

For the geographical distribution of this species I refer to the list of species at p. 20.

Nymphon macronyx, G. 0. Sars (PI. XV". figs. 1-7).

Nymphon macronyx, G. 0. Sars. Prodromus descriptionis, &c., Archiv. f. Math, og Naturvid.,
ii. 265, 1877.

Of this interesting inhaljitaut of the cold area of the Faroe Channel about thirty
specimens were cbedged during the cruise of the " Knight Errant." As hitherto neither a
full description nor any figure of this species has been published, I wish to give both here.

Only a short diagnosis of this species has been published by Professor G. 0. Sars.
From this, and from the pencil cbawing he had the kindness to send me, the species is
easily recognised. However, in some respects, I observed slight differences from the
diagnosis of Professor G. 0. Sars. Prol)ably these will be found to arise from the
fact that the species had been submitted only to a preliminary investigation by the
celebrated Norwegian zoologist.

Nymphon inacronyx, G. 0. Sars, is a somewhat robust Nymphon, having the second
joint of the palpi longer than the third, the first tarsal joint not quite half the length of
the second tarsal joint, and having a very long claw at the end of every leg and

' Nature, September 2, 1880, C. Wyville Thomson, the Cruise of tlie " Knight Errant."

«6 THE VOYAGE OF H.M.S. CHALLENGER.

extremely small auxiliary claws. Moreover, it is characterised by a ciu'iously-shaped
oculiferous tubercle. Its dimensions are as follows : —

Length of the proboscis, ....

2-3 Dim

Total length of the body, ?, . . .

5-4 „

Total length of the bodj^, $, . . .

5-7 „

Length of the ovigerous leg, ?, . . .

6-4 „

Length of the ovigerous leg, <?, .

7-1 „

Length of the leg of the third pair, .

18 „

T • 1 1 P ■ 1

The body is almost quite smooth, while the appendages are richly furnished with
hau's. The slenderness of the body is not veiy great ; the lateral processes, however,
are widely separated (PI. XV. fig. 1). The cephalothoracic segment is shorter than the
proboscis ; it is narrow in the middle, while it shows a considerable swelling at the
beginning and at the end. The oculiferous tubercle is situated above the insertion of the
ovigerous legs. Seen laterally this shows the conical and pointed shape described by
Professor G. 0. Sars ; but seen from the front it is considerably flattened and broad,
terminating in two divergent points. It is furnished with four distinct eyes (PI. XV.
fig. 2). The i^roboscis is almost quite cylindrical. The abdomen is short.

Of the appendages I have figured the mandiljles in fig. 3 on Plate XV. The second
joint is nearly triangular, and almost its whole surface is covered by strong hairs. At
the front one of the angles of the triangle terminates in the immovable claw, which is a
great deal shorter than the movable one. Both claws bear a row of spines, and are
strongly curved at their extremities.

The drawing I have given in fig. . 4 of the palpi renders, I believe, a description needless.

The ovigerous leg of the female is shorter and feel^ler than that of the male ; more-
over, it has the fourth and fifth joints quite straight, whereas the same joints in the
male describe distinct curves. The relative length of the joints is the same as in most
other species of the genus Ny million. In the male the sixth joint is furnished with a
small pointed tubercle, which I did not observe in the female. The males bear the eggs
on the fourth and fifth joints ; they are large and collected in one or two packets on both
legs. The four last joints show a row of denticulated spines of the shape figured on
Plate XV. fig. 5. The claw at the end of the ovigerous leg is strong and pectinated at
the extremity.

The second joint of the legs is twice as long as the first and the third, the fourth
joint is as long as the fifth, the sixth is only a little longer. The first tarsal joint is not
quite half as long as the second. The claw is very long, almost as long as the second
tarsal joint. Very small auxiliary claws, easily overlooked, are situated on both sides of
the great claw (fig. 7). The second joint of the female is consideral^ly swollen at the
end, where it shows on every leg a large genital pore of an oval shape ; the fourth joint in
the same sex is also swoUen. The hairs on the first four joints in Ijoth sexes are not
very numerous, whereas, beginning with the fifth, the last joints are richly furnished

REPOET ON THE PYCNOGONIDA. 97

with hairs. The Bide of the eighth joint facing the claw shows a I'ow of regular strong
spines. The genital pores of the males are smaller than those of the females ; they are
present only on the two posterior pairs of legs.

As for the geographical distribution of this species, G. 0. Sars dredged it in lat. 62°
44' 5" N., long. 1° 48' E., in comparatively deep water (412 fathoms), in the cold area.
He found there only four specimens, whereas a single haul with the trawl in the Faroe
Channel yielded among a thousand specimens of Nymphon rohusttim, Bell, upwards of
thirty specimens of the species in question. This occurred at

Station No. 8 (cruise of the "Knight Errant"). Lat. 60° 3' N., long. 5° 51' W.
August 17, 1880. 540 fathoms. Cold area.

This station is not very far from the place where it was dredged by Professor G.
0. Sars, and as this is the only instance, so far as I know, of this species having been
collected previous to the cruise of the " Knight Errant," most probably it has a very
restricted distribution.

Nymphon robustum, Bell.

NympJion rohustum, Bell, Belcher's Last of the Arctic Voyages, vol. ii. p. 409, 1855, Tab.
XXXV. fig. 4.

Nymphon abyssurian, Norman, WyviUe Thomson, Depths of the Sea, p. 129, 1873.

Nymphon hicms, Heller, Crustaceen, Pycnogoniden und Tunicaten der K. K. Oester. Ungar.
Nordpol Exped. Denkschriften der Wiener Akademie der Wiss., xxxv. 41, 1875.

Nymphon rohustam, Bell, G. O. Sars, Prodromus Crustaceorum et Pycnogonidarum, Arch. fib-
Math., og Naturvid., ii. 265, 1877.

An ample discussion of the s}Tionymy of this species, and a description of those
parts of the body which have hitherto been overlooked, I have given in my paper on the
Pycnogonids of the cruises of the " AVillem Barents," to which I have referred above.
An immense quantity of this true cold area species was dredged during the recent
cruise of the " Knight Errant." Mr Murray writes to me that this was the greatest
haul of Pycnogonids he ever observed. It is a blind species, and along with it were
trawled a considerable number of specimens of Nymphon macronyx which have distinct
eyes, about ten specimens of Nymphon stromii also furnished with eyes, one sj)ecimen of
Nymphon grossip>es with eyes, and four specimens of Colossendeis proboscidea, Sabine
(sp.), which is again without eyes. The number of specimens with eggs is not very
considerable, and there is not one which shows the numerous highly developed young
ones clinging to the ventral side of the body of their parent as is the case with some
specimens from Barents Sea.

Finally, I wish to point out that the dimensions of the " Knight Errant " specimens are
considerably smaller than those of specimens from higher latitudes. As I have mentioned
a,bove, this is also the case with the specimens of Nymphon stromii.

(ZOOL. CHALL. EXP. — PART X. — 1881.) K13

98

THE VOYAGE OF H.M.S. CHALLENGER.

A species of Scalpellum, which, so far as I know, has not been observed hitherto,
is a common commensal on the legs of Nym^yhon rohustum. Bell.

This species was dredged at

Station 8 (cruise of the "Knight Errant"). Lat. 60° 3' N., long. 5° 51' W. August
17, 1880. Depth of the sea, 540 fathoms. Cold area. Perhaps 1000 specimens.

Station 2 (cruise of the "Knight Errant"). Lat. 60° 29' N., long., 8° 19' W. July
28, 1880. Depth of the sea, 375 fathoms. Warm area. One specimen only.

This single specimen from the warm area must, most probaljly, be considered as one
which has strayed from the cold area. As far as I know, the species has not been
observed at a lower latitude than 60° N.

Nymphcm rohiistum, Bell.

Colossendeis proboscidea, Sabine (sp.).

Phoxichilus prohoscideus, Sabine, Marine Invertebrate Animals in a Supplement to the Appendix

of Captain Parry's Voyage for the Discovery of a North- West Passage in the years 1819-

1820, London, John Murray, 1824, p. ccxxvi.
Colossendeis horealis, Jarzynsky, Prtemissus Catalogus Pycnogonidarum inventarum in mari glaciali

ad eras Lapponire rossicre et in mari albo, anno 1869 et 1870. Annales de la Soc. des

Naturalistes de St P^tersbourg, vol. i., 1870.
Colossendeis proboscidea, Sabine (sp.), G. O. Sars, Prodromus descriptionis, &c., Archiv. fiir

Math, og Naturvid., ii. 268, 1877.

Of this interesting species, the first of the genus Colossendeis that was observed, four
specimens were trawled at Station 8, together with many specimens of Nymphon

REPORT ON THE PYCNOGONIDA. 99

robustum, Nymjylion Tuacronyx, &c. (See above.) There is one veiy young specimen,
and the three others are females. For figures and a full description of this species I again
refer to my paper on the Pycnogonids of Barents Sea.^

The specimens trawled by the " Knight Errant" are not quite so large as those from
Barents Sea.

Station 8 (cruise of the " Knight Errant"). Lat. 60° 3' N., long. 5° 51' W. August
17, 1880. Depth of the sea, 540 fathoms. Cold area.

Pycnogonum litorale, Strom (sp.).

Phalangiuin litorale, Strom, Physisk og oeconomisk beskrivelse over fogderiet Sondmor, belig-

gende in Bergens Stift i Norge, 4°. Soroe, 17G2-66, pi. i. fig. 17.
Pycnorjonum litorale, O. Fabr., Fauna Groenlandica, p. 223, 1780.
Pycnogonum litorale, Miiller, Zoologia Danica, iii. 68, pi. cxix. figs. 10-12, 1789.
Pycnogonum litorale, Krdyer, Nat. Tidsk. Ny Eaekke, i. p. 126, 1845.

Of this very common species one specimen was dredged at 53 fathoms. It occurs
only in the neighbourhood of the coast, and ranges to the north as far as the White Sea,
where Jarzynsky (Prsemissus Catalogus, &c., loc. cit.) collected it on the coast of Russian
Lapland, and as far south as the coast of the Mediterranean. Westward it is common at
difierent places on the North-American coast, and it also abounds on the east coast of the
Atlantic — as on the English, Dutch, French coasts, &e. Slater (Ann. and Mag. of Nat.
Hist, V. series, vol. iii., 1879) describes a variety of this species — it is a little more
slender — collected on the coast of Japan. Most probably, therefore, the species will also
be found to occur along the whole northern coast of Siberia.

The single specimen trawled in the neighbourhood of the Scottish coast is a male
with distinct ovigerous legs. It was dredged at

Station No. 3 (cruise of the "Knight Errant"). Lat. 59° 12' N., long., 5° 51' W.
August 3, 1880. Depth of the sea, 53 fathoms.

' TMs same species has been recently described by Mr E. J. Miers under the name Anomorhynchiis smithii,
n. gen., n. sp., from specimens collected by Mr Leigh Smith a little to the south of Franz-Josef Land (Annals and
Magazine of Natural History for January 1881, p. 50, pi. vii. figs. 6-8). (Note inserted during the correction of the
last proof.)

100 THE VOYAGE OF H.M.S. CHALLENGER.

APPENDIX II.

CONTEIBUTIONS TO THE ANATOMY AND EMBRYOLOGY OF THE

PYCNOGONIDA.

Our knowledge of the anatomy and embryology of the sea-spiders is very insufficient ;
of those living in shallow water we know but little, and of the deep-sea forms nothing.
Whereas a priori it is evident, that in general the deep-sea animals will exhibit the same
anatomical structure, and pass through the same development as the littoral or shallow-
water forms ; it is also clear, on the other hand, that a comparison of the anatomy of
animals inhabiting very different depths might lead, at least in the case of some organs,
to very interesting results.

As the rich material collected during the voyage of H.M.S. Challenger enabled me to
study the anatomy of at least some genera {Nymphon and Colossendeis), I eagerly made
use of this opportunity ; in the first place, in the hope of increasing our knowledge of the
morphological structure of the group, so that the question of their position in the zoological
system might perhaps be settled ; and in the second place, to try in this way to illus-
trate the mode of life of those deep-sea animals which belong to our group.

My original intention of going through the whole anatomy of the Pycnogonids I have
given up, seeing that, however good the condition of the material might be, yet in regard
to some organs, — intestine, heart, &c., — and for the histological structure of most organs, it
by no means takes the place of fresh material. Moreover, as I learned after a great part
of my anatomical researches was finished that Dr Dohrn's Monogi-aph is forthcoming, I
determined to limit the publication of my researches to those organs which had sufi"ered
least from having been in alcohol for so many years. These are the integument, with
its glands ; the nervous system, with the sensory organs ; and the reproductive organs.
In regard to the intestine, the heart, &c., only some incidental observations were made,
which, in so far as they are thought important enough, will he recorded also.

1. Integument. — The integument of the Pycnogonids is only known from the publica-
tions of Zenker (1855),^ myself (1877),' and Dohrn (1879).' Zenker was the first to
observe the numerous cavities in the chitinous cuticle of Pycnogommi litorale. I,
however, had the good fortune to demonstrate that these cavities communicated by

1 Zenker. — Untersuctimgen iiber die Pycnogoniden, Miiller's Arcliiv, 1852.

2 Hoek.— Ueber Pycnogoniden, Niederliindisches ArcMv fiir Zoologie, iii., 1877.

3 Dokm.— Neue Untersuchimgen iiber Pycnogoniden, Mitth. Zool. Stat. Neapel., i., 1879.

EEPOET ON THE PYCNOGONIDA. 101

means of very narrow canals with the exterior, and that they occur in all the genera of
Pycnogonids (at least in those I had then studied — Nijmiyhon, Pallene, Phoxichilidium ,
and Pycnogonum). Moreover, I pointed out that as no respiratory organs are
present in the Pycnogonids, respiration must necessarily be integumentary ; it was my
conviction in 1877, as it is still, after a minute investigation of the Challenger material,
that the principal function of these canals is to serve for respiration. Contrary to
this opinion, Dohrn asserts that the cavities, with the pore-canals, which he says, were
rightly described by me, "zur Aufnahme von Hautdriisen dienen." To settle this
question I investigated the structure of the integument of many species belonging to
different genera. I studied it in Nymplwn hamatum, N. longicoxa, N. brachyrhynchns,
and iV". hrevicaudatimi ; in Colossendeis leptorkynchus, C. gigcis, and C. 2^'>'oboscidea ;
in Ascorhynchus glaber and A. orthorhynchus ; in Pallene australiensis ; and in Phoxi-
chilidium patagonicum, P. pilosum, and P. insigne.

Notwithstanding that my researches were especially directed to this point, I only
once succeeded in observing the glands referred to by Dohrn, and although I grant it is
possible that in some cases this may be owing to the condition of the animals, yet I feel
sure that as a rule these glands are not present.

A short description of the integument may find a place here. It always consists
of a subcuticular layer (epithelium), and of the chitinous cuticle. The subcuticular
epithelium is of a protoplasmic nature, with nuclei imbedded in it^ (PI. XVI. figs. 1 and
17, f) ; the chitinous cuticle in the different species shows a very different thickness,
and always presents a stratified appearance. It is never calcified, and, as a rule, is
coloured yellow by picrocarmine. Often, however, it shows two distinct lam i use ; an
internal very thick one, coloured violet by the picrocarmine, and consisting of numerous
alternately lighter and darker strata, and a comparatively thin external one, which
assumes a yellow colour when treated with picrocarmine (PI. XVI. fig. 1). To strengthen
the often extremely long and slender joints of the legs (especially the thighs and the two
tibial joints), the chitinous cuticle is often furnished internally with one {Ascorhynchus
glaber, PI. XVI. fig. 9) or two {Nymp)hon hamatum, Phoxichilidium insigne) longitudinal
ridges, which project into the interior of the leg. The form of these ridges on a transverse
section is by no means always the same, as may be seen from the figures 6, 9, 11, 16, 17,
and 18 on PI. XVI. The septa of connective tissue, which in most genera divide the
cavity of the joints of the leg {Colossendeis, e.g., fig. 16, PI. XVI.), often have a point
of attachment in these ridges.

As a rule the chitinous cuticle of the Pycnogonids is perforated by two kinds
of cavities, the one of an irregular conical shape, terminating externally in a narrow
pore-canal ; the other much narrower, and rather more cylindricaUy shaped, is filled

' The subcuticular epithelium of Pallene australiensis, Hoek, is richlj- furnished with a dark brown pigment. I
did not observe this in any of the other species.

102 THE VOYAGE OF H.M.S. CHALLENGER.

with a iDrotoplasmic substance, often containing nuclei. No doubt it is the protoplasmic
epithelium which fills these latter canals. A nerve passes through them, and terminates
at the surface of the cuticle in what Dohrn {loc. cit., p. 38) calls a " Borstenapparat."
Dohrn never observed a single seta' at the end of these canals ; but always two or more
(sometimes even a rosette of eight or nine) together. This observation of Dohrn's
seems to be most accurate ; as a rule I found the integument of the species of Nymiohon
furnished with forked setae (PL XVI. figs 1, 2, 4, 7), one of the setae being often split
again (fig. 3) ; that of Pallene australiensis shows also forked setas ; the integument of
Ascorhynchus glaber is also furnished with double setae, which are here extremely small
and rudimentary. One of the species of Phoxichilidium (P. imtagonicum) shows a
combination of four or five (PI. XVI. fig. 17), whUe in another species {Phoxichilidium
pilosum) two combined setae are always observed.

In Colossendeis setae are totally wanting ; and thus in this respect the genus
Ascorhynchus, with its rudimentary setae, stands between Nymphon and Colossendeis.

According to Dohrn,^ this pore-canal, which terminates in these forked sette, " often "
takes its origin from one of the integumentary cavities, which he saw filled up with glands.
Dohrn therefore considers these setae as tactile organs, having probably the special
function of causing on irritation, by reflex action, the secretion of a poisonous fluid by
the glands, which are situated in the conical cavities of the integument. I think this
a very ingenious supposition, but I wish to state in opposition to it, that according to
what I have seen of the matter — (l) as a rule the cylindrical and narrow pore-canals do
not originate in the conical cavities ; and (2) that the occurrence of the glands in the
conical cavities is the exception, and that, as a rule, these cavities are empty or partly
filled up with a protoplasmic substance, nuclei, blood-corpuscles, &c. In the difi"erent
species of Nymphon it hardly ever happens that the pore-canal with the set« takes its
orio-in in a conical cavity ; in the species of Phoxichilidium it does not seem to be so rare
(PI. XVI. fig. 17), even in these species, however, it is by no means the rule.

With regard to the form of the conical cavities, in the first place it must be men-
tioned, that they have a most regular conical shape in the difi"erent species of the
genus Nymphon, and also in some species of Pallene. In Phoxichilidium they are of a
more elongated form, and often a small lateral branch passes from the main canal near
the extremity (PI. XVI. fig. 1 7, h). The genus Colossendeis shows these cavities of a
much more irregular shape. As a rule every cavity is bifid, and terminates in two
narrow pore-canals (PL XVI. fig. 12, c). The cavities are usually almost quite filled
up with protoplasmic substance. In this genus I once observed distinct cells, with large

1 Huxley calls " seta; " all the hair-like processes from the flue microscopic clo-svn to stout spines, which are found
on the outer surface of the cuticle (Crayfish, Loiulon, 1880, p. 197). I use the word here, and on the following pages,
in a much more restricted sense ; having already used the words hairs and spines for the integumeutaiy appen-
dages, I call " setas " those which I consider as being more pwticularly of a sensory nature.

2 Loc. cit., p. 38.

REPORT ON THE PYCNOGONIDA.

103

nuclei, in these cavities. This was in the first tibial joint of the leg of Colossendeis
leptorhynchus ; however, I think there can be no doubt that these same cells will also be
found in the other joints of the legs of this species. Each cell terminates in a long and
slender appendage, which probably extends to within a small space of the opening of the
canal. Most probably these are the glands which, according to Dohrn, are always present
in these integumentary cavities. I have figured these glands in fig. 1 of Plate XVIII. ; { is a
part of the wall of the intestinal csecum, which runs through the joint ; c, c are parts of the
septa of connective tissue, which seem to form here separate chambers in connection with
the difierent cavities. These chambers contain numerous blood-corpuscles of an irregular
spool form, and towards the pore-canal are furnished with two {cl), in an other cavity
three {d') glandular cells, with very large nuclei. The specimen, the integument of
which shows these glands, is a female.

Returning to these integumentary cavities, and their ordinary, viz., their respiratory,
function, I have stiU to mention that I found them in many species with many blood-
corpuscles in their interior, and that often also a nerve is seen which sends a very thin
branch into them. These I observed more accurately in Colossendeis 23'>'oboscidea, Sab.
(See later, under peripheral part of the nervous system.)

The number of these cavities is different in the diff"erent species. I counted them in
transverse sections of the fourth joint of the leg in some fourteen species, belonging to
five genera, and compared them with the girth of the joint. This I did to ascertain if
there was any relation between the number of these cavities and the depth at which the
species lives. That such a relation does not exist, and that the greater or smaller number
of these cavities is one of the properties of the natural groups (genera) of the Pycnogonids,
is shown, I believe, hj the following table : —

Name of the Species.

Circumference in

millimeters of

the fourth joint

of the leg.

Number of
integumental

cavities
in a transverse

section.

Numlier
per millimeter.

Depth
in fathoms.

Nymphmi hrevicaudatum, Miers, .

3-25

5

1-54

73

Nyinphon hrachyrhynchus, Hoek, .

1-52

22

14-4

83

Nymplion rohustum, BeU,

4-6

27

5-9

4.58

Nijmplwn longicoxa, Hoek, .

2-35

12

5-1

1100

NyynpJwn hamnttim, Hoek, .

3-47

37

10-7

1488

Ascorhynclms orthorliynchus, Hoek,

3 '4

90

26-5

130

Ascorliynchus yfaber, Hoek, .

3

56

18-6

1375

Colossendeis proboscidea, Sab. (sp.),

10-2

106

10

540

Colossendeis leptorhynchus, Hoek,

3-37

63

18-7

1126

Colosseiideis hrevipies, Hoek, .

3-15

62

20

2650

Pallene australiensis, Hoek, .

2-4

20

8-3

79

Phoxichilidium insigne, Hoek,

1-57

41

26

14

Phoxichilidium patugonicum, Hoek,

5-2

112

21-5

117

Phoxichilidium pilosiim, Hoek, .

4-17

45

10-8

1790

104 THE VOYAGE OF H.M.S. CHALLENGEK.

When comparing the number of these cavities in the fourth joint of the leg with that
of the same organs in a transverse section of the body, — for example, between two lateral
processes, where the circumference of the body is in some species nearly the same as that
of the fourth joint of the leg, — I observed almost the same number of cavities. This
was the case at least in Nymphon hamatxim and in N. hrachyrhynchus ; whereas in
the other species more or less considerable diflferences were observed, the number of these
cavities in some species being greater in the legs ; in others, on the contrary, round the
body.

With regard to the hairs and spines on the surface of the body, I have already pointed
out above that, as a rule, species occurring at great depths are rather smooth, whereas
those from shallow water are furnished with numerous hairs and spines. Thus Nymphon
longicoxa and N. hamatum have the surface almost quite destitute of spines ; Nymplvon
hrevicaudatum and N. hirtipes occurring at moderate depths, the former not exceeding
120 fathoms, the latter never reaching 300 fathoms, and generally found in considerably
shallower water are the most hairy species of the genus. On the contrary, Nymp>hon
hrachyrhynchus, occurring at depths not exceeding 120 fathoms, is almost as smooth
as Nym2ohon hamatum.

The species of Colosse7ideis, and especially the three more accurately studied by me,
show almost a perfectly smooth surface. The sensory setse are wanting also in these species ;
and the few spines which are present are very short and conical (PI. XVI. fig. 13). Of
these three species, two are true deep-sea inhabitants; but the third (Colossendeis
prohoscidea, Sab. (sp.), as a rule, is found at a depth not exceeding 200 fathoms. Of the
species of Ascorhynchus, the smooth A. glaher is found at a depth of 1375 fathoms ;
but the surface of Ascorhynchus orthorhynchus is also not very hairy, yet this species
occurs at a depth of only 130 fathoms.

The shallow water genera Achelia and Ammothea are extremely hairy, whereas in
the genus Phoxichilidium some of the deep-sea species (P. pilosum and P. moUissimum)
show a particularly hairy surface. Both the spines and the set^ are in these species of
a very remarkable length. Finally, Pallene australiensis, occurring at a depth of 38 to
120 fathoms, shows again the smooth surface of a true deep-sea species.

The form of these spines is also very different, but I think it is not necessary to describe
them. In some species the spines are not smooth, but serrated ; as, e.g. , in the case of
Nymphon hrevicaudatum, Miers, and Pallene australiensis, Hoek (PI. XL figs. 6, 7) ; and as
spines having a very curious shape I have pointed out already those of the sixth joint of the
ovigerous leg of Nymp)hon longicoxa. No doubt, these must be of great use to the animal in
holding the egg-masses, and perhaps also in furnishing a good point for the young ones to
cling to. Particularly interesting are also the so-called denticulate spines in the four last
joints of the ovigerous legs of most species. I may refer to the descriptive part of this report
for an account of their extremely different forms, their numbers, and their arrangement.

REPORT ON THE PYCNOGONIDA. 105

Different as tie forms of these spines may be, their minute structure is always the
same, and, I think, quite identical with that of any other spine. The cuticle is perforated
at the place where the spine is inserted, and a thin and flexible part of this cuticle keeps
the spine in its place ; a socket is thus formed in which the spine easily moves. The
spine itself is, near its insertion, cylindrical and hollow, and its cavity is entirely or
partly filled with a protoplasmic substance, which is in continuity with the epithelium
of the integument. Towards the extremity the spine is flattened, chitinous, and no
longer hollow ; the exterior margin of this flattened part is serrated {Nymphon), or
provided with extremely small teeth (Colossendeis). Originally I considered these spines
as being of a sensory nature ; but afterwards, as I was convinced of their chitinous composi-
tion, I changed my opinion. However, as it is not diflicult to trace a nei-ve, at least in
some of the more transparent species, penetrating these spines, they may still be considered
a.s, to a certain extent, organs of feeling. On the other hand there are, perhaps, far more
important functions to be fulfilled by the ovigerous legs with the aid of these denticulate
spines, viz., those of seizing the food, and, last, not least, of holding the animal of the
other sex during the act of copulation. In most species where denticulate spines occur
the four last joints of the ovigerous legs often lie rolled up spirally, with the row^s of
denticulate spines turned inwards. These joints if wound round one of the legs or any
other part of the body of the animal with which it copulates, would necessarily secure a
very strong adhesion in consequence of the rows of spines.

In close relation with the integument are the glands, which occur in different
appendages of the<ibody.

1. The glands of the palpi. These I observed in Discoarachne brevipes, where they
occur in the third joint of the palpi, and probably theii- secretion is poured out through
a sieve-like perforated spot at the end of the second joint (PL VII. fig. 10). In the
palpus of Ascorhynchus such a gland is also present. It is situated in the fifth joint, and
has the form of a long sack, whose wall is lined by small and very numerous glandular
cells. It is attached to the wall of the joint of the palp by means of numerous threads
of connective tissue, and it opens towards its distal extremity by means of a rounded
pore. In Ascorhynchus orthorhynchus this pore is placed at the tip of a small conical
excrescence ; but in Ascorhynchus glaber I did not observe this knob. Probably the
same glands occur also in other genera — e.g., in Colossendeis — but I could not ascertain
their presence.^

2. The glands of the ovigerous legs. These I oliserved in Nymphon, but their minute
structure can only be studied in fresh specimens. They open into a small pore, not far
from the beginning of the fourth joint of the leg. Each gland seems to consist of the

' The glands of the palpi are mentioned in Dohni's paper of 1879. He says of the nerve of the palpus : " Er um-
fasst auf seinem Laufe ein sonderbares, bisher unbekannt gibliebenes Excretionsorgan " {loc. cit., p. 31).

(ZOOL. CHALL. EXP. PART X. 1881) K 11

IQg THE VOYAGE OF H.M.S. CHALLENGER.

true crlandular part and of a wider part, which acts probably as a receptaculum and opens
into the fine pore.'

3. The glands in the fourth joint of the legs of the males. These I observed in the
follo^ving species : — Nymphon hamatuvi, Nymphon hrachyrhynchus, Ascorhynchus glaber,
Colossendeis lexjtorhyndius,.Colossendeis prohoscidea, Colossendeismegalonyx, Oorhynchus
aucklandm, Phoxichilidium insigne, and Pallene australiensis. Whether or not they
occur in the thighs of the males of all the species I dare not assert. I can only say that
1 did not find them in the thighs of the following species : — Nymphon robustum,
N. hrevicaudatum, N. longicoxa, N. grossipes, and Colossendeis gracilis. This may,
however, be the consequence of these glandular masses being present only during a short
period of the year — for example, only in the breeding season.

These are the glands which were observed by Dohrn. According to him {loc. cit.,
p. 36) they occur only in the male sex, and are found in the fourth joint of the legs, viz.,
m those joints in which in the females the ovaries are most strongly developed. Dohrn,
moreover, tells us that these glands are extremely variable in their appearance ; while in
Ammothea they are furnished with a single duct only, in Phoxichilus there are fifteen
smaller openings. Dohrn supposes that the function of these glands is to secrete a viscous
tiuid, wherewith the males agglutinate the eggs which have been laid l^y the females,
and attach them to their ovigerous legs.

As to the function of these glands, I was unable to make any observations from the
material preserved in spirits and brought home by H.M.S. Challenger. With regard to
their structure the following may be stated : — The glands are always composed of a
skeleton of connective tissue, the meshes of which are or are not filled with nucleated
cells, which doubtless are the true glandular cells. When these glands have the meshes
filled up with the nucleated cells (PL XVI. figs. 5 and 10), the 'skeleton of con-
nective tissue is not easily discerned ; while in those cases in which the meshes
are empty (PL XVL fig. 15) the structure of the connective tissue is easily observed.
In the form of the glandular cells small differences were also observed. In Ascorhynchus
glaber, they are fusiform and pointed at both extremities ; in Nymphon hamatum,
they are rounded, but in both cases distinct nuclei are present. A considerable
difference, moreover, is seen in the greater or less degree of concentration which
the glandular masses had undergone. In Nymphon hamatum and in Ascorhynchus
glaber the gland in the fourth joint (which, however, in the latter species is also
present in the fifth joint of the leg) forms only a single mass, which runs through
the whole joint and opens at the one side in a row of pores, each of which is placed at
the tip of a chimney-lilce process. As seen in fig. G, the gland in Nymp>hon hamatum
almost extends on the one side of the leg, between the intestinal cfficum and the

' These glands are also obseiTed by Dolini ; he calls tbem " eiu zvveites uoch grdsseres Excretions- (oder Dnisen \-)
Organ (Ibid.).

REPOflT ON THE PYCNOGONIDA. 107

wall, £i*om the one longitudinal ridge to the other ; whereas in Ascorhynchus glaber
(fig. 9) the row of pores is placed almost exactly opposite to the single but very strong
ridge.

In Pallene and Phoxichilidium the structure and the position of the glands show
nothing particularly interesting. In Pallene there are many pores, in Phoxichilidium
insigne only a single pore at the end of the joint, placed at the tip of a conical
excrescence (PI. XVI. fig. 18A;). The structure of these glands in Colossendeis
is extremely interesting. In the three species of this genus in which I studied them,
Colossendeis leptorhynchus, Hoek, Colossendeis megcdonyx, Hoek, and Colossendeis pro-
hoscidea, Sab. (sp.), the gland consists of very numerous more or less isolated parts of
a rounded or more longitudinal shape, each of them opening separately by a distinct pore,
or {Colossendeis prohoscidea) three or four opening together in a single pore. In fig. 14
on PI. XVI. I figure a part of the integument of Colossendeis megalonyx magnified ;
in fig. 15 of the same plate a part of the integument of Colossendeis leptorhynchus is
shown. The glands seem to correspond with a wide vesicle (o), in the interior of which
a narrow canal (p) lies wound spirally ; this canal is easily traced till it opens at the
pore. Those conical cavities into which the glands are seen penetrating are much wider
than the others. For the structure of the gland itself the specimen of Colossendeis leptor-
hynchus which I investigated was not all I could have wished. On a transverse section it
looks quite as if all the original glandular cells had dropped from the connective tissue,
this tissue itself being the only part that remained as an empty skeleton. Perhaps the
state of preservation is to a certain extent the cause of this. The male specimen of
Colossendeis prohoscidea, in which also I studied these glands, was in a much better
condition. Plate XVIII. fig. 2 shows the distribution of the glands {g) over nearly
half the inner circumference of the skin of the fourth joint. Moreover, in fig. 3 a small
part of this skin is figured more strongly magnified with the glands opening into one of the
pores. The gland itself {g) shows a dense ball of round and nucleated glandular cells. A
comparatively wide and very transparent canal extends from the gland to the interior ot
one of the integumentary cavities (c), and a very narrow duct {d), which is irregularly
rolled up, runs through this wide canal till it reaches the pore at the end of the cavity.
When studying a part of the skin of the leg from the interior it is easily seen that three
or four of these glandular bodies send their ducts into the same integumentary cavity.
From the beautifully developed net- work of nerves and ganglionic plexuses, which extends
over the whole inner sm-face of the integument, distinct nerves are seen arising and
penetrating the cavities or innervating the glands.

Finally, I wish still to mention the curious manner in which these glands of the
fourth joint of the male open in Oorhynchus aucklandice, Hoek. A very long
cylindrical appendage is inserted on the fourth joint a little behind the middle. The
gland opens at the tip of this appendage by means of a very long duct, which shows

108 THE VOYAGE OF H.M.S. CHALLENGER.

a distinct swelling (a kind of receptaculum) near the beginning.^ About the structure
of the gland itself in this species I have no observations to communicate.

2. Nervous System. — Of the different systems of the Pycnogonida the one most
eao-erly studied is, without doubt, the nervous system, and this is tjuite natural, because
it has been rightly considered, that if any system could be expected to shed Hght on
the affinities of the Pycnogonids with the other Arthropoda, it would be the nervous
system.

Among the more important papers on the subject, those of Zenker, Semper, Dohrn, and
myself may be mentioned. The way in which Zenker {loc. cit.) treats of the nervous
system of Nijnvplion is not a very happy one, as he descril)es and figures it as consist-
ing of a supra-oesophageal ganglion and four thoracic ganglia. The account given by
Semper^ of the nervous system of this genus is much more accurate. He tells us that in
Nymphon the supra-oesophageal ganglion innervates the mandibles and the eyes, and that
the first of the five thoracic ganglia furnishes nerves to the proboscis, to the palpi, and
to the ovigerous legs, while the four following ganglia give off nerves to the four legs.
The number of thoracic ganglia is, according to Semper, also five in PaUene and in Achelia,
on the contrary only four were observed by him in three species of Fhoxichilnlhim. In
my paper the optic nerves of Pycnogonum are described, and the numljer of gangha in
Nymjyhon is given as five, in Pycnogonum as four.^ We find in Dohrn's latest paper {loc.
cit., p. 37) a much more detailed description of the structui^e of this system. The supra-
oesophageal ganglion innervates the mandibles, and, moreover, gives ofi" an azygous nerve,
which dorsally innervates the proboscis, and forms a ganglion at about one-third from
the extremity of the proboscis. The first thoracic ganglion gives ofi' three pairs of nerves ;
the first pair arising from the ganglion a little outside and below the insertion of the
circum-cesophageal commissures, innervates the lateral parts of the proboscis. Like
the azygous proboscideal nerve, they form ganglia at about one-third from the
extremity of the prolwscis, and these three ganglia are connected by commissures, which
thus form a secondary oesophageal ring. The second pair innervates the so-called palpi ; the
third arises from the ganglion laterally towards the posterior part, it innervates the ovigerous
legs. Moreover, Dohrn observed that this first thoracic ganglion not only in the genera
furnished with palpi and ovigerous legs, but also in those forms which have lost their
palpi and even in the females, which have lost also their ovigerous legs, consists of three
nuclei of " fibrilliiren Punktmasse," each of which gives off" the fibres for the nerves re-
spectively of the proboscis, palpi and ovigerous legs. In a young stage of the embryological
development, Dohrn made the observation that the first ganglion really consisted of two

1 Sucli a long appendage, at the tip of which the gland opens, occurs also in Ammothea (Dohrn, loc. cit., p. 36).

2 Semper (C), tjber Pycnogonideu und ihre in Hydroideu schmarotzenden Larvenformen (Arljeiten a. d. Zool.-
Zoot. Institut in Wiirzhurg, i., 1874, p. 278).

3 Loc. cit., p. 249.

REPORT ON THE PYCNOGONIDA. 109

not quite separated pairs of ganglia. Finally, Dohrn states in the same paper tliat besides
the five (six) double ventral ganglia there are two others, which, however, in some
genera, totally disappear, and in other genera are preserved only in a rudimentary con-
dition. Accordingly, Dohrn observed immature stages of Phoxichilus, in which, behind
the sixth ventral ganglion, were present two distinctly separated, although much smaller,
pairs of long ovate gangHa. C)f these the first pair gives off no nerve, and the second pair
the two nerves for the abdomen.

For my observations with regard to the nervous system of the Pycnogouids, I made
use of the following specimens from the material of the Challenger Expedition : — one of
N'tjmj)ho)i hamatum, one of Nymphon hrachyrhynchus, two of Nymphon hr^vicaudatum,
Miers ; numerous specimens of Nymphon rohnstum, Bell ; one of Colossendeis leptor-
hynchus, one of Coloasendeis megalonyx, and one of Colossendeis proboscidea, Sab. ;
finally, one of Phoxichilidium pilosum. What I tried to ascertain in my investigations
was, in the first place, the innervation of the cephalic appendages and of the proboscis,
in the second place the structure of the first thoracic ganglion, in the third place
that of the last thoracic ganglion, and the presence or absence of the two rudimentary
abdominal ganglia. In how for I have been successful in this may be judged from the
following : —

The nervous system consists in all species of Pycnogonids of a supra-oesophageal
ganglion, an oesophageal commissure, and five (seldom four) thoracic ganglia. The
supra-oesophageal ganglion is situated in the cephalothoracic segment ; however, its place
varies greatly with the form of the segment, and therefore it even shows small difierences
in the different species of one genus. The differences in the difierent genera are more
considerable. In the genus Nympjhon it is, as a rule, placed towards the hinder
extremity of the cephalic part of the cephalothorax, below the oculiferous tubercle, and
above the insertion of the two ovigerous legs. In the genus Colossendeis this
ganglion is found nearly in the middle of the cephalic part of the cephalothoracic segment,
which part is usually separated (distinctly in Colossendeis lepAorhynchus, e.g.) from the
remaining part of the segment by means of a constriction ; the oculiferous tubercle
is here exactly above the ganglion. In Phoxichilidium the ganglion is found also
above the insertion of the ovigerous legs ; but the oculiferous tubercle is in most species
of this genus situated quite anteriorly, on that part of the cephalothoracic segment which
overhangs the proboscis. As a rule the shape of this ganglion is round (PI. XVIII.
fig. 6), but in Colossendeis the comparatively small ganglion is much broader than long
(PL XVIII. fig. 4). Whereas, in the other genera the two oesophageal commissures are
very short, run parallel to each other, and enclose a narrow canal through which only
the oesophagus passes (PI. XVIII. fig. 11 C), in Colossendeis (I observed it in Colossendeis
leptorhynehus, Hoek, and in Colossendeis prohoscidea. Sab., sp.) this canal is very wide
(PI. XVIII. fig. 4), the commissures which connect the supra-oesophageal ganglion with

110 THE VOYAGE OF H.M.S. CHALLENGER.

the first thoracic ganglion are very long, and through the wide canal formed by these
not only the intestine passes but also two large muscles (PI. XVIII. fig. 7), which serve
for the movement of the proboscis, and run from the posterior margin of the proboscis to
the hinder jiart of the dorsal surface of the cephalic part of the cephalothorax. These
muscles are anteriorly narrow, and grow considerably broader towards their extremity,
so that their shape is rather triangular. The nerves which arise from the supra-
cesophageal ganglion are the same in Ni/mplion, Phoxichilidium, and Colossendeis. To
the front three comparatively strong nerves are always present.' Of these, that nerve
which is placed in the middle takes its origin in the ventral surface of the ganglion,
a little behind the front mai'gin. This middle nerve is the azygous proboscideal nerve.
It runs close to the dorsal surface of the prolioscis, and gives off at rather irregular dis-
tances extremely small nerves, which innervate the integument. At a distance of about
one-fourth of the total length of the proboscis in Nijmplwn, and of about one-eighth of the
same length in Colossendeis, it enters the ganglion (PI. XVIII. fig. 8), which, no doubt,
has already been observed l)y Dohrn. The two mandibular (antennary) nerves arise from
the front margin of the supra -oesojihageal ganglion ; they are nearly (in N[imphon and in
Phoxichilidmm) of the same strength as the azygous proboscideal nerve. First they are
slightly divergent, then they approach each other again so as almost to touch the azygous
proboscideal nerve, then they separate again and direct themselves forwards and a Uttle
upwards, running in the mandibles very close to that part of the dorsal surface which is
nearest to the mandible of the other side (PI. XVII. fig. 4, n.m.). In regard to the
farther course of the mandibular nerve I could only observe that it divides into two
liranches. These nerves are not totally wanting in the genus Colossendeis, and con-
sidering the case of Colossendeis gracilis with its distinct mandibles, we need not
wonder at this. Yet the nerves are very short and represented only by rudimentary
branches (PI. XVIII. fig. 4, m). (Those of the interesting specimen of Colossendeis
gracilis I was unable to observe ■^nthout dissecting the specimen.)

With regard to the innervation of the eyes, I observed distinct nerves arising from the
supra-oesophageal ganglion. These I have described already in my paper on Pycnogonids,
published in 1877, and their presence is confirmed by Dohrn's observations. Dohrn {loc.
cit., p. 37) says that they arise from the sides of the ganglion, and that they are widely
separated from one another. Moreover, Dohrn tells us that there are two of them, and
that they divide and innervate the eye in a peculiar way. I studied the innervation of
the eyes in Nymphon brachyrhynchus, N. stromii, N. robustum, and in Colossendeis
2')roboscidea. The latter species is a blind one ; its eyes are represented only by a small

' In the figure I give of the nerves arising from the sxipra-cEsophageal ganglion of N. rohustum (PI. XVII. fig. 4),
liesides these three nerves two thinner ones are figured. These, however, are not present, as I ascertained after the plate
was printed off. Although I have given myself much trouble in trying to determine what it was I had mistaken for
nerves, I have not succeeded. The thin threads have the appearance of narrow ducts ; they extend backwards to
behind the supra-oesophageal ganglion and pass between this ganglion and the upper surface of the oesophagus.

REPORT ON THE PYCNOGONIDA. Ill

rounded spot distingiuHlialjle by its transparency. The optic nerves are represented by
two strong bundles of nerves, arising as in Colossendeis megalonyx (PI. XVIII. fig. 4, o)
laterally from the dorsal anterior surface of the ganglion. These nerves divide into
stronger and feebler branches, and the latter have small ganglia between them. Such
small ganglia are present also on the interior surface of the small transparent spot
representing the rudimentary eye. They are in relation partly with the nerve fibres
of the so-called optic nerve, pai-tly with the complicated system of nei-ves and ganglia,
which covers in this species as in the other species of the same genus, the internal
surface of the integument. In this species of the genus Colossendeis, and from what I
have seen of the matter, the same is the case in Colossendeis leptorhynchus and C
megalonyx, the optic nerve-bundles are really integumentary nerves, giving ofi" the
nerve-branches, which, as wUl be shown hereafter, extend all over the inner surface of
the integimient, having everywhere ganglia between them, and, as a rule, at small dis-
tances from one another.

I feel inclined to consider the condition of the eye, and of its innervation as described
for Colossendeis proboscidea, as the original condition in the Pycnogonida. As an
example of the most highly developed condition, I wish to describe that of Nymphon
hrachyrhynchus. DorsaUy the supra-flesophageal ganglion gives ofi" two nerves, which
are at their origin quite covered over by ganglion cells (PL XVIII. fig. 11 C. o').
Where they arise from the ganglion, the distance between the two nerve-bundles is not
very considerable ; they diverge slightly till they reach the base of the oculiferous
tubercle. Here each of these nerve-bundles divides into two branches which run
horizontally, the one towards that part of the integument which is before, the other
towards that behind the oculiferous tubercle. On reaching the integument each of these
two branches divides into numerous smaller nerves and nerve-fibres ; moreover, they
send upwards numerous nerve fibres, which penetrate the oculiferous tubercle and extend
till they reach the outer wall of the eye. There can be no doubt, therefore, that the eye
is innervated by nerve-fibres not united together so as to form a distinct optic nerve.

The same mode of innervating the eye I observed in Nymphori stromii. For the
study of the innervation of the rudimentary eye of Nymphon rohustum I got good pre-
parations also. A part of one of these is figured in Plate XVIII. fig. 5. We have the
same nerve-bundles covered by ganglionic cells ; they do not, however, divide immediately
into the stronger integumentary and smaller optic nerves, but before doing so they enter
a comparatively large ganglion (fig. 5, g) from which these nerves are seen arising.
This same ganglion gives off also the nerves for the setse, which in this species are
present in considerable number at the tip of the oculiferous tubercle,^

^ This quite corresponds with Doliru's observations, that the optic nerves give off also branches to the curious
organs oljserved by him between the eyes. I believe these organs are rudimentary in Nymphon, in Colossetideis proboscidea
they are totally wanting.

112 THE VOYAGE OF H.M.S. CHALLENGER.

While the eye of Colossendeis prohoscidea, Sab., must probably be considered as
the most primitive condition, that of Nymphon rohustum is undoubtedly a degenerated
form. In the innervation of the different stages of development of the eye of the
Pycnogonids I believe I have pointed out one common feature, viz., that the two
nei-ves arising from the supra-cesophageal ganglion may be only partly considered
as optic nerves, and that it is much more in accordance with the facts to call
them integumentary nerves, branches of which have assumed the function of optic
nerves. For the investigation of the development of the organs of sense and especially
of the eyes, I believe the study of the Pycnogonida will yield in future very interesting
results.

The nunilxT of thoracic ganglia in Nymphon, Colossendeis, and PhoxicMlidium
pilosum is five. Those of Colossendeis (C. prohoscidea, Sab., s]3.) are figured in
Plate XVII. fig. 2 ; those of Nymphon rohustum, Bell, in fig. 3 on the same plate.
In these three species the first ganglion (better called the first ganglionic mass) is
separated from the second by two distinct commissures, and in Nymphon rohustum
and Fhoxichilidiurn pilosum even the outward form of the ganglion shows its complex
nature ; on a longitudinal section it is seen to be composed of two distinct ganglia.
This anterior ganglionic mass supplies the two ventral parts of the proboscis, the
palpi, and the ovigerous legs ; three pairs of strong nerves are given ofl' by the
ganglion, which, judging from its anatomical structure and from its development [vide
Dolirn, loG. cit., p. 34, and also in this report sxd) embryology, with PI. XIX. figs. 11 and
13) is composed of only two pairs of original ganglia.'' For a long time I was greatly
puzzled with this fact, until the study of the nervous system of Colossendeis dispelled
my doubts.

In fig. 4 of Plate XVIII. I figure the suj)ra-oesophageal and first thoracic ganglia
of Colossendeis megalonyx. The latter gives ofi" the two nerves for the ovigerous legs
(o), the nerves for the palpi (pa), which in the same way as the nerves for the
legs immediately divide into two branches, and in the third place the two nerves for the
proboscis {t"). Moreover, a fourth nerve (t') is observed, which serves also for the
innervation of the proboscis, and the fibres of which arise from the same part of the
ganglion as those of the main proboscideal nerve. For a short way these fibres run
parallel with the fibres of the commissures, so that this first pair of proboscideal
nerves seems to arise from these commissures.^ These same nerves are also present in

' On page 32 of the same paper, DdIiiti asserts that in the first thoracic ganglion tliree nuclei are present of the
well-known " tibrilliiren Punktmasse." This does not agree with what I have seen in the three genera I studied, nor
does it agree, I believe, with what Dohrn himself says on page 34.

^ In fig. 2 on Plate XVII. the ventral part of the nervous system of Colossendeis prohoscidea, Sab., sp., is figured.
From the first thoracic ganglion arise the nerves for the ovigerous legs (n. o. I.), and a strong nerve (the palpus nerve)
dividing into two branches (?i. jn. and n. p.). The most anterior, and at the same time most dorsal, part of this ganglion,
from which arise the two pairs of proboscideal nerves, and the commissures, has not been figured, having been removed
during the preparation.

REPOKT ON THE PYCNOGONIDA. 113

Nijmphon in a much more rudimeutaiy state. Nobody would conclude, however, from
their presence that the first ganglion was originally composed of four gangha ; Ijut the
supposition of its being formed of three nuclei loses at the same time much of its value,
and the ventral part of the proljoscis must be considered as l)eing innervated Ijy the same
original ganghon as that which gives off the nerves for the palpi.

I believe there can be no doubt that we have here the original condition of the
nervous system ; at the same time this fact may be considered as suggesting the opinion
that the palpi originally belonged to a pair of appendages which coalesced to form the
two undermost of the three parts of which the proboscis is composed.

The two front nerves of the first thoracic ganglion in Nymjihoii and Phoxichilidium,
and the strongest of the two front nerves of the same ganglion in Colossendeis,
enter the proboscis and run forwards exactly in the middle of the two ventral parts
of the proboscis, which I compared (note on p. 14) with the carpels of a monocoty-
ledonous fruit. These nerves I caU the paired proboscideal nerves. They end, like the
azygous proboscideal nerve, by entering a ganglion, placed at a1)0Ut the same distance
from the end of the proboscis as the ganglion of the azygous proboscideal nerve. These
tluree gangUa are united by a ring, which runs between the outer wall of the proboscis
and the c4iitinous wall of the oesophagus, among the numerous muscles which ran from
the one wall to the other.

So far my description quite agrees with that of Dohrn, as given above. Ho\\'ever, a
considerable difference arises from the fact that the ganglia which were seen by Dohrn
are not to be considered as ganglia of the azygous or paii'ed proboscideal nerves, but
as being really the terminal ganglia of three strong nerve buncUes, composed of nerve
fibres and ganglia, which run longitudinally below or above the three stout proboscideal
nerves, so that they lie between these nerves and the wall of the oesophagus. The
discovery of these three ganglionic nerve buncUes has been very fortunate. It is curious
that they have hitherto been always overlooked, and especially that Dolu-n did not
observe them. But then it must he considered that these nerve l^undles are placed
among numerous muscles running over and beneath them, and making a preparation
totally impossible. A successful longitudinal section, made exactly above or IdcIow a
buncUe, is the only way to detect it. I call these bundles ganglionic, for although
I do not believe that their function is analogous with that of the s}Tiipathetic system
of higher animals, yet their structure shows in general the same relative distrilxitiou
of ganglion cells and nerve fibres as in the case of the ganglionic system of higher

animals.

Fig. 6 on Plate XVIII. shows the position of these nerves in the proboscis ; while
fig. 8 shows a part of one of them more strongly magnified. Each of them {g) consists
of a strong l^undle of nerve fibres, which, posteriorly at irregular, anteriorly at more
recrular distances, are surrounded l)y groups of ganglion cells. Thus each of the

D T- 1 -■

(ZOOL. CUALL. EXr. — PART X. — 1881) -''^

114 THE VOYAGE OF H.M.S. CHALLENGER.

cords has the appearance of a row of ganglia connected by bundles of nerve fibres.
The size of these ganglia is not quite the same over the whole cord, the foremost being
slightly larger than those placed more posteriorly. As to their shape, I observed the
following two different types. In some of the ganglia the cells are placed on both
sides of the Ijundle, which passes through it, and these ganglia have a very regular
rhomboidal form. The other type is represented lay those ganglia in which ganglion
cells are to he oloserved only on one side of the nerve bundle, and which accordingly
show a triangular form. The triangular ganglia seem to be more numerous in
Colossendeis, the rhomljoidal form in Nymphon; in both genera, however, the stout
ganglia, which are placed in the front part of the cord, and in the first place the
comparatively large ganglion (figs. 6 and 8 y) oliserved by Dohrn are of a distinct rhom-
l^oidal form.

The form of the ganglion is, of course, determined Ijy the number of nerves which
branch off from it. The different ganglia give off besides numerous smaller nerves,
one (in the triangular form) or two (in the rhomboidal) stouter nerves. These run in
the foremost part from the one ganglionic Ijundle to the two others, and form nerve-
rings (fig. 6, c&' a"- «'"■ &c.), of which the secondary oesophageal ring (figs. 6 and 8 a)
observed by Dohrn is the first and the stoutest. In Nymjohon rohustum I observed five
or six of these nerve rings, but in Colossendeis they are still more numerous.

With regard to the three stout proboscideal nerves, which have been observed already
by Semper and Dohrn, and which, according to the latter author, terminate in the three
ganglia (the front ganglia of my ganglionic bundles), I have ascertained that they are
connected with the ganglionic bundles in the following way : — They run superiorly to and
quite independently of the ganglionic Ijundle, till they reach the last but one ganglion of
that bundle (fig. 8 u). This they enter, their fibres passing through it and contributing to
the comparative thickness of that part of the bundle which unites the last l)ut one and
the last of the ganglia (fig. 8 y). However, it is very probable that at least some of these
fibres extend Ijeyond the last of the ganglia. I am not quite certam whether perhaps,
a union of the ganglionic cord with the proboscideal nerves does not also take place
posteriorly. As I have stated akeady al)ove, the proboscideal nerve gives ofi" branches ;
and about the middle of the proboscis of Colossendeis prohoscidea, Sab. (sp.), on both sides
of the stouter middle nerve two thinner cords run parallel with it in its immediate neigh-
liourhood ; these are branches of the middle nerve. Investigating the first part of these
lateral branches, close to their origin from the main proboscideal nerve, I once observed
(m Colossendeis megalonyx, Hoek) very small ganglia with thin nerve threads runniuo-
along this nerve without, however, exchanging fibres ; these are, possibly, the end
branches of the ganglionic bundle. While the origin of these branches and their
connection with the proboscideal nerves is so easily noticed, with regard to their
termuiation I only observed that the Ijundles, when approaching the end of the proljoscis.

REPORT ON THE PYCNOGONIDA. 115

become thinner and thinner, the ganglia smaller, and the lateral branches arising
from the ganglia more numerous and much thinner and shorter. This is quite in cor-
respondence with the number of muscles which these ganglia innei-vate ; whereas
these in the front part of the proboscis are stouter, and separated by distinct longitu-
dinal intervals, in the posterior part they are thinner, and placed almost in an uninter-
rupted row.

This brings us quite methodically to the function of these ganglionic nerve-bundles.
In the vertebrates we can distinguish by the microscopical structure sympathetic ganglia
and nerves from those of the cerebro-spinal system, but in the invertebrata this is by
no means so easy. In the first place, we must consider the function of the part of the
nervous system in question. The ganglia and the nerves of my three ganglionic
bundles innervate the striped muscles of the proboscis. Unstriped muscular fibres
are by no means rare in the muscular tissue of Pycnogonids,^ but even if they
were quite wanting, as they seem to be in the muscular tissue of the Crayfish,' those of
the proboscis ought to be considered as voluntary fibres. Moreover, the action which
the food undergoes in the proboscis by means of these fibres is of a purely mechanical
nature. Chemical action does not take place in it, therefore comparison of these
o-angliouic bundles with the sympathetic system of higher animals is impossible.

The morphological explanation of their presence is by no means so easily given. The
following reasoning must be considered as an attempt only. The proboscis of the Pycno-
gonida in the form in which it presents itself should not, of course, be considered as a new
organ, only present in this class of Arthropoda. It is only an organ or a combination of
organs under a new form, modified under the influence of surrounding conditions. Con-
sidering for a moment the supposition right, that it results from the union of three parts,
an azygous one placed partly alcove and partly before the mouth (the upper lip),
and two others placed below and Ijehind the mouth, the manducating parts of the
mandibles, of which the palpi in that case may be considered as the feelers ; then we
have in the three nerves, the first of which is given ofi" by the supra-cesophageal ganglion,
and the two others arising from the first thoracic ganglion, the normal nerves for the
innervation of these parts. With the union of these parts to form a proboscis) and I
believe this argument will hold good also if we prefer another homology for these parts),
and the predominance of the manducating function of this proboscis, evidently quite a
new part of the nervous system, will make its appearance ; and it is not difiicult to
imagine its probable origin. .

In the chitinous wall which lines the canal of the proboscis, and which is furnished
with rows of very numerous teeth and spines, we have, no doubt (morphologically), a con-
tinuation of the integument, so that its inner surface corresponds with the outer surface of
the body, while its outer surface, to which the muscles are attached, is the homologue

1 E.g., in the wall of the vasa efferentia of the males, &c. * Huxley, The Crayfish, p. 181.

116 THE VOYAGE OF H.M.S. CHALLENGER.

of the inner surface of the skin. Now, this inner surface of the integument both of the
body and the legs, especially in si^ecies of the genus Colossendeis, is richly furnished with
ganglia, which spread all over it, and are connected wth nerves. They are so very
numerous as to form a continuous network of ganglia and nerves, their function being,
I believe, to innervate the cavities of the integument, for which I have suggested a
respiratory function. There can therefore l^e no difficulty in supposing that the ganglia
of my ganglionic bundles are derived from originally integumentary ganglia, and that
their high development is to be attributed to the changed functions of the parts which
surround the mouth.

While these same ganglionic bundles, in a more or less developed state, are found
in all species and genera of Pycnogonida, it is very probable, I believe, that in the other
classes of the Arthropoda their homologues' will be sought for in vain. The shape of the
terminal ganglia, of which the dorsal one is the largest, is best seen from the drawing
(PI. XVIII. fig. 8). Of the nerves which arise from it, two run in an oblique direction
(one to each side), these enter again (at least in Npnj^hon) a small ganglion, from which
nerves are given off to the tactile organs placed in the so-called lips of the proboscis.
Of these small ganglia, those two, which are placed on both sides of one of the lines of
union of the three jjroboscideal parts, are again connected by means of a nerve string.
The tactile organs consist of a small tuft of hairs placed just at the end of the chitinous
list which marks the place of union of two of the proboscideal parts meeting there
laterally. Perhaps the nerve fibres of the small nerve bundles, which enter the secondary
ganglia and innervate these tactile hau--tufts, take their origin in the three original
proboscideal nerves.

Besides the three original nerves and the three ganglionic bundles, two thinner
nerves enter the proboscis dorsally. These I observed only in Nij-niphon arising from
the supra-CBsophageal ganglion. The two thin nerves which in Colossendeis run along-
side and quite near to the main proboscideal nerve must be considered as branches of
this main nerve, and no doubt there are still other longitudinal nerves, which run
through the proboscis, and which must also be considered as branches of one of the three
main nerves.

What I observed in regard to the remaining part of the nervous system is the
following : — The shape of the four thoracic ganglia may be seen from the figures on
Plate XVII. The length of the commissures uniting these ganglia is different in
different genera, and even in the different species of one genus. In Nym2ohon rohustum,

' It seems to me that an analogous case is that of the visceral or stomatogastric nerves of the Crayfish, studied by
different authors, and investigated recently more accurately by Prof. Huxley (Anatomy of Invertebrated Animals,
London, 1877, p. 330), a complex nervous apparatus, serving chiefly for the innervation of the muscles of the mandibles,
<and lor that part of the intestine which has been called by Huxley the gastric milL This gastric mill of the Decapod
Crustacea is placed behind the cosophageal commissures ; the analogous apparatus of the Pycnogonids is found in front
of the same commissures.

REPORT ON THE PYCNOGONIDA. 117

Bell, e.g., the commissures between the third and fourth ganglia are the longest ; in
Nymplion hrachyrhijnchus, however, those between the second and third are the longest.
In Colossendeis and in Phoxichilidium inlosum the relative length is the same as in
Nym'phon rohustum. In all the species and genei'a I observed the commissures between
the last two thoracic ganglia to be shorter, often much shorter, than those between the
preceding ganglia. The nerves which arise from these ganglia in Colossendeis immediately
divide into two branches, whereas in Nymplion they only separate after having reached
the middle of the lateral process at the end of which the leg is inserted. In Phoxi-
chilidium pilosum they again divide immediately after leaving the ganglion. The last
ganghon has a truncated form ; in most of the genera I studied I observed at least a
trace of the presence of the small accessory ganglia (abdominal ganglia) which Dohrn
observed in Phoxichiliis, and which I found beautifully developed in a young specimen
of Colossendeis proboscidea.

Close to the hinder margin of the ganglion two smaU excrescences arise from its
dorsal surface. They are separated from one another hy a small space, and as they unite
again at a short distance from the ganglion a round area is left between them. In a
full-grown specimen of the same species only a single excrescence was observed, arising
from the hinder margin, and I obsei"ved it of the same form in Colosseiideis megcdonyx
and also in C. leptorhynchzis. I did not oljserve it in Nymphon; but in the species
of that genus which I studied (iV. strbmii and N. rohustum) I always saw two distinct
medullary nuclei in the interior of the ganglion placed close to its hinder margin, behind
the large medullary masses from which the nerves for the hindmost pair- of legs arise.

According to Dohrn, the nerves which arise from this ganglion are two in number,
besides the two stout nerves for the hindmost pair of legs. It is extremely difficult to
avoid confounding threads of connective tissue, arising from the neurilemma that surrounds
this ganglion with nerves. I have, however, distinctly oljserved that often four different
nerves branch of from the ganglion ; in Colossendeis prohoscidea, e.g., two smaller ones
are given off more in the middle from the dorsal excrescence, and two stouter ones
leave the ganglion nearer to the nerves which innervate the fourth pair of legs. Two
pairs of nerves arising from the hinder surface are also present in G. leptorhynchus ; but,
strange enough, only one pair (that arising from the excrescence in the middle of the
hinder margin) in Colossendeis megalo7iyx. In the genus Nymphon the two nerves which
arise from the ganglion leave it as one single nerve, and only afterwards divide into two
branches. The same difficulty is experienced in ascertaining the presence of nerves
branching from the commissures which unite the different thoracic ganglia. These are
present, however, in all the genera, and even in all the species I studied. As a rule, they
leave the commissures much nearer to the preceding than to the following ganglion, but
often also nearly in the middle of the commissures; between the second and third,
between the third and fourth, and between the fourth and fifth thoracic ganglion,

118 THE VOYAGE OF H.M.S. CHALLENGEE.

distinct nerves are observed arising at an acute angle from the commissures. These
innervate the muscles whicli run from the one segment to the following one.

I give a figure (Plate XVIII. fig. 10) of one of the smaU ganglia and the nerve
fibres arisins; from it on the inner surface of the integument. I observed these ganglia

O O DO

in Nymphon and in Colossendeis ; they are more numerous in the latter genus, and
especially numerous and in a better state of preservation in one of the specimens of
Colossendeis j^^'oboscidea, Sab., dredged last summer north of Scotland. The figure is
taken from a part of the integument of a specimen of this species.

To show the minute structure of the ganglia I give in fig. 1 1 A-F a series of six figures
illustrating vertical (frontal) sections through the supra-oesophageal and first thoracic
ganglia. As will be easily seen, the sections do not form a complete series, they are only
the most interesting out of a series of about twenty. Fig. A represents a section
c[uite at the front of the supra-oesophageal ganglion ; a distinct and comparatively thick
neurilemma sheath surrounds the whole ganglion, and three distinct medullary nuclei
(pointed sul^stance according to Leydig) show the place of origin of the tliree main
nerves. The rest of the section is composed of ganglion cells, with the exception of a
small meduUary spot at the left side, which does not occur at the other side,
and proves that the section is somewhat oblique. Neither the oesophageal com-
missures nor the fii'st thoracic ganglion are yet to be seen in this section. Fig.
B represents a section which passes through the supra-oesophageal ganglion and
through the foremost part of the first thoracic ganglion, but not yet through the
commissures. Almost the w-hole section is occupied by the medulla, which forms
regular prominences towards the periphery, and only a very small space is occupied l)y
the ganglion cells ; m is the lobe for the mandibular (antennary) nerve, o represents the
lobe for the optic nerve, and x is a median lobe about the function of which I do not feel
(piite sure. In section C this median lobe is no longer to be observed, and the optic
lobes have here assumed a much more elongated form. In section B the commissures
are still totally wanting, but the front part of the first thoracic ganglion, with the
meduUary nuclei (j)) for the two infra-proboscideal nerves, are distinct. These in
section C are reduced to small lobes, while those for the nerves of the ovigerous legs (t)
are distinct. In this section the oesophageal commissures are seen, and also the under-
most parts of the two optic nerves, which arise from the supra-oesophageal ganglion
(o'). Their connection with the optic lobes, however, does not occur in this section.
Section C passes almost through the middle of the oculiferous tubercle, so that two eyes
are placed in front of this section and the two others behind it. Section D represents the
last part of the supra-oesophageal ganglion ; the hindmost part of the medulla is seen, and
the ganglion cells begin again to increase in number. Of the first thoracic ganglion, the
section goes through that part of the medullary centrum which gives off the nerves fur
the ovigerous legs (/). In E this medullary centrum is considerably less voluminous, and.

REPORT ON THE PYCNOGONIDA. 119

finally, iu F only two rounded spots of medulla are left {co'), wliicli give off the com-
missures between this and the second thoracic ganglion.

About the histological structure of the ganglia I wish to be very short. In fig. 12 on
Plate XYIII. a longitudinal section is given of the first thoracic ganglion of Nijmijhon
Irachyrhynchus. A comparatively thick sheet of connective tissue (neurilemma sheath)
surrounds the ganglion, and is in continuation with the sheatli of the commissure which
unites tliis ganglion with the second thoracic ganglion. Small ganglion cells, each
with a distinct nucleus, fill that part of the ganglion wliich is not occupied by the nerve
fibres. These ganglion cells are situated in meshes of connective tissue, they are small
and furnished with but little protoplasm ; their nuclei are distinct, and show a small and
eiitterino; nucleolus.

In a section through the first thoracic ganglion of Colossendeis leptorhynchus,
it is easily observed, that the ganglion cells are of two difi"erent sizes : there are
very large ones rich in protoplasm, and furnished with comparatively large nuclei ;
there are also very small ones, which show only a small quantity of protoplasm. Fibres
and sheets of connective tissue are everywhere observed between the o-ano-lion cells ; the
neurilemma sheath of the ganglion itself is very thick, whether it is to l^e considered
as really double (an outer and an inner neurilemma sheath, the latter of w^hich should be
in connection with the connective tissue meshwork of the interior of the ganglion), I have
not been able to ascertain.'

3. Eyes. — Of the organs of sense I paid si^ecial attention to the eyes. Besides the
tactile organs spread over the whole surface of the body, the curiously shaped hairs of the
palpi oi Ascorhynchus, and perhaps of other genera, which probably are also organs of a
special sense (olfactory ?), the eyes are the only certainly known organs of sense in
Pycnogonids.^ In the first place, I tried to ascertain in how far the eyes can really be
said to disappear in those animals which inhabit great depths. I therefore drew up the
following list, in which the species from the " Challenger " and " Knight Errant " expedi-
tions are placed according to the depths they inhabit.

1 Hithertu I have studied only such sections of the ganglia as are made by cutting the whole body. These are
sufficient for researches on the general anatomy, but totally insufficient wth regard to histology. The numerous sheets
and strips of connective tissue prevent the substance used for enclosing the body (paraffine or Calberla's substance) from
penetrating the ■whole interior of the body. Thus some parts always remain disunited, and the cutting of thin sections
is extremely difficult, if not impossible.

2 The curious organ which Dohm observed between the two eyes on each side of the oculiferous tubercle I have
not observed. Perhaps it does not occur in Nymphon, the only genus in which I investigated the eyes.

120

THE VOYAGE OF H.M.S. CHALLENGER.

Name of Species.

Depth

iu

Fathoms.

Number
of Eyes.

Condition of tlie Eyes.

Oliservations.

Discoarachne brevipes, Hoek, .

Four.

Small ; placed on a blunt tubercle.

Hannonia typica, Hoek, .

J5

Small ; placed on a rounded tuljercle.

Phoxichilidium Jlitmincnse, Kroyer,

7-2()

)J

Two anterior a little larger than

the two posterior.

Phoxichilidiuvi insif/iic, Hock,

7-20

Jf

Size of the eyes different, as in the
foregoing.

NympJion brachyrhynchus, Hotk,

10-1211

ft

Large ; oculiferous tubercle pointed.

Nyinphoii brevicaicchitum, Miers,

25-125

J)

Small ; oculiferous tubercle ex-
tremely elevated.

Nymphon fuscum, Hoek,

25

J)

Small; touching one anotlier at
the tip of a not very prominent
tubercle.

Aacorhynchrtg miniifug, Hoek,

38

A blunt oculiferous tubercle,
without eyes or pigment.

Pallene langinda, Hoek, .

38

Four.

Small ; oculiferous tubercle not
very prominent.

Pallene Uevia, Hoek,

38-40

)?

Middle-sized; tubercle blunt and

low.
Middle-sized; tubercle acute.

Pallene australiensis, Hoek, .

38-120

PhoxicUiUdiwm patcujonicum, Hoek,

45-120

17

Two anterior large, the two pos-
terior much smaller. Tubercle
high, but blunt.

Form of the tubercle differs
with age.

Pycnorjmium litorale, Strom, .

53

,,

Extremely small; tubercle blunt.

Colossendcis mcyaloiuj.r, Hoek, .

55-120

ji

Two anterior a little larger llian
the two posterior. Tubercle ele-
vated.

Form of the tuliercle differs
with age.

Nymplion yrossipes, Oth. Fabr., sp.,

83-540

V

Large ; placed at the base of a high
and acute oculiferous tubercle.

Nymphon brevicollum, Hoek, .

83

))

Large ; oculiferous tul.iercle low.

Oculiferous tubercle ob-
liijuely truncated.

Colossendeis robusfci, Hoek,

120

)}

Two anterior large, two posterior
small ; oculiferous tubercle ele-
vated and acute.

Ascorhynchus oiihorhynchus, Hoek, .

150

))

Middle-sized, with pigment ; oculi-
ferous tubercle acutely pointed.

Nymphon 7-obustum, Bell,

375-540

• . .

No lens, and no pigment.

Colossendeis leplurhynchus, Hoek,

4(10-1600

...

Two small spots (rudimentary
lenses >.) at both sides of tlie
blunt tubercle.

Younger specimens with a
more elevated tubercle.

Nymphon stromii, Kroner,

515-540

Four.

Two larger ones directed forward,
two smaller ones l)ackward.
Tubercle blunt.

Nymphon macronyx, G. 0. Sar.^,

54t)

)>

Not very large ; tubercle bifid at
the extremity.

Colossendeis proboscidea, Sab. (sp.), .

540

Two snuxll spots (rudimentary
lenses?) on joth sides of the
ocuhferous tubercle.

Tubercle of the youuger
specimens elevated.

Phoxichilidium patac/oniaim,

600

Fom-.

Two large eyes directed forward.

var. eleyans,

two smaller ones directed back-
ward. Tubercle high, acute.

Oorhynchus audlaudia:, Hoek,

700

)»

Small, with pigment ; tubercle
directed forwards.

Nymphon perUicidmn, Hoek, .

825

...

Oculiferous tubercle low,
without pigment.

Nymphon lonrjicOMi, Hoek,

1100

Four.

Small ; the pigment light-lirown-
ish ; tubercle low and Ijlunt.

Nymphon compactum, Hoek, .

1100

...

...

Oculiferous tubercle repre-
sented by a round .spot.

Colossendeis miitvta, Hoek,

1250

Two small rudimentary
spots, without pigment;
tubercle blunt.

Ascorhynchus glabcr, Hoek,

1375

...

Oculiferous tubercleelevated.

REPORT ON THE PYCNOGONIDA,

121

Name of Species.

Depth

in

Fathoms.

Numher.
of Eyes.

Condition of the Eyes.

Ohservations.

Nymphon hamatum, Hoek,

1375-1600

...

...

Oculiferous tubercle also
rmUmentary.

Colossendeis gigas, Hoek, .

1375-1600

Oculiferous tuljercle of the
younoerspecimens higher,
and furnished with two
rudimentary spots.

Colossendeis gracilis, Hoek,

1375-1600

...

...

Oculiferous tubercle much
elevated, with four lenses.

Phoxichilidium pilomni, Hoek,

1600-1950

Four.

Two large ones directed forward,
two very small ones backward ;
tubercle elevated and acute.

Nymphon meridionale, Hoek, .

1675

))

Distinctly pigmented; tubercle not

very high.
Two very large ones and two small

Phoxichilidium oscitans, Hoek,

1675

>j

Phoxichilidium mollissimum, Hoek,

1875

))

ones.
Two extremely large ones, kidney-
shaped, directed forward ; two
very small ones directed back-
ward.

Nymphon proceriim, Hoek,

2160

...

t..

Two small spots are pre.sent
on the tip of a low
tubercle.

Nymphon longicollum, Hoek, .

2225

...

...

Oculiferous ttibercle high,
with two rudimentary
spots without pigment.

Colossendeis media, Hoek,

2225

...

...

Oculiferous tul^ercle very
high and acute.

Colossendeis hrempes, Hoek,

2650

...

...

Oculiferous tubercle high
and acutely pointed.

"What we learn from this Hst is that it is a common feature for the shallow- water
species to have four distinct eyes ; and for those inhabiting a depth exceeding 400 fathoms
to have no eyes, or to have rudimentary eyes without pigment. While exceptions to
this rule are rare in the shallow-water species, they are by no means unfrequent in the
deep-sea species. As to the structure of those eyes which may be called rudimentary,
they often have a distinct lens — a rounded spot marked by its brightness ; they are quite
destitute of pigment, and, as I learned from a section of the oculiferous tubercle of
Nymphon rohustum, Bell, the small eye has no retina, and is filled up with a mass of
detached connective tissue.

In those species which are furnished with distinct eyes, the size of those on the same
tubercle is not always the same. In Nymphon stromii, Kroyer, the eyes which are
directed forwards are slightly larger than those which are directed backwards, iDut this
difference is much more marked in the species of Phoxichilidium. This difference in size
— as is generally known — is a common occurrence. Grenacher^ has shown in the simple
eyes of the Arachnida and also of the larvae of many insects, that this difference in size
is often accompanied by extremely interesting differences in the minute structure. It

' Qrenacher, H. — Untersuchungen iiber das Sehorgan der Arthropoden, 4o, Gottingen, 1879.

(ZOOL. CHALL. EXP. PART X. 1881.) K IC

122 THE VOYAGE OF H.M.S. CHALLENGER.

would be of interest to study this question in the Pycnogonida, but the hmited number of
the specimens of the different species of Phoxichilidium in the Challenger collection did
not allow me to study their eyes. I investigated those of Nymphon stromii, l:)ut there
the difference in size is slight ; I did not ascertain any difference in theii- structure.

The knowledge of the minute structure of the eyes of the Pycnogonids is of very
recent date. They were always considered as simple eyes, and were even mentioned
as such by Cavanna. Dohrn, therefore, in the preliminary publication on the results
of his studies on Pycnogonids, is the first who gives us some information on these
organs. According to him the eyes, taken in a vertical position, are of a pointed
oval shape ; ^ they have a retina composed of modified epithelium cells (hypodermic
cells), the extremities of which are surrounded by a brown pigment ; the cuticula forms
a lens.

Among the latest investigations into the structure of the eyes of the Arthropoda, those
of Grenacher, published in his splendid memoii",^ have the merit in the first place not
only in proposing a homology between the parts composing a compound and those com-
posing a simple eye, but also in showing the existence of this homology throughout almost
the whole type of the Arthropods. Moreover, the value of his monograph with regard
to the physiology of the organ of sight, and the immense quantity of special information
which it contains, is at present almost inestimable. In investigating the eyes of the
Pycnogonids, I was extremely desirous to try whether the scheme for the eye of the
Ai-thropods, as proposed by him, would hold good also in the case of the Pycnogonids.
Though my researches did not give me a complete idea of the anatomy of theii" eyes,
I think my results are worth publishing here, because they admit of comparison with
the scheme given by Grenacher.^

I made numerous preparations of the eyes of different species of the genus Nymphon ;
of N. brevicaudatitm, Miers, N. brachyrhynchus, Hoek, N. stromii, Kroyer, and of
the rudimentary eyes of Nymphon robustum, Bell. I studied more especially those I
made of Nymphon brachyrhynchus and of Nymphon stromii. While the eyes of Nymp)hon
stromii (PI. XVIII. fig. 11, B) are comparatively small, and placed on the sides of a conical
tubercle, so as to be separated by a greater distance from one another below than above ;
those of Nymphon brachyrhynchus are larger, and are placed on the inside of a cyLLudrical
oculiferous tubercle, so close to one another as to meet at their inner sm-faces. In fig. 2,

' Von oben nach unten spitz oval {loc. cit., p. 37).

- Grenacher, H. — Untersuchungen uber das Sehorgan der Arthropoden, 4°, Gottingen, 1879.

' For studying tlie histology of the Arthropod's eye fresh material, in the first place, is necessary. That I
got preparations fit to be used of the eyes of Nymphon brachyrhynchus, collected at Kerguelen Island, and put in
spirits in January ia74, is almost more -than could be expected. In one respect only did the concUtion of the material
hinder me, viz., that I could not make iise of some reagents, e.g., of nitric acid. Thongh used of different strengths, I
never obtained the solution of the pigment ^vithout the visual rods being destroyed also. Consequently I never got
a preparation sho-^ving the connection between the fibres of the optic nerve and these rods.

EEPORT ON THE PYCNOGONIDA. 123

Plate XXL, I figure a longitiidinal section of one of the eyes of this species ; and in the
same figure the place occupied by the outer surface of the eye of the other side is indicated
(a). This outer surface is invested by a thin chitinous cuticle, which is minutely (longi-
tudinally) striped ; round the circumference it is in connection with the chitinous skin
of the animal. The inside of this wall is covered with pigment, and it is in this bed of
pigment that the union of the fibres of the optic nerve with the elements of the retina
takes place. I have abeady spoken above about the manner in which the optic nerve
penetrates the eye. I sometimes got preparations, which made me believe that the optic
nerve reached the outer integument of the oculiferous tubercle, at a considerable distance
below the eyes, and that it ran along this wall and penetrated the eye where it is in
connection with this integument; this, however, is not reaUy the case. Numerous
separate nerve fibres reach the under surface of the eye ; they then penetrate its cuticle,
and in one of my preparations I observed distinctly, that they are in direct connection
with the rods of the retina.

In the interior of the eye there is a retina, but there is no distinct vitreous body.
I observed that under the thickened cuticula which forms the lens of the eye, just as
everywhere else, the epithelium (hypodermis) of the cuticula is formed of rucUmentary
ceUs represented by nuclei. Of a distinct row of vitreous body ceUs, like those figured
and described by Grenacher {he. cit.) and Graber,^ I obsei-ved nothing. Nor do I
believe that Dohrn's assertion is right, that in the eyes of the Pycnogonida the retina
is derived from the epithehum cells (hypodermic cells). This retina consists of rod-
forming elements and of ganglion cells. Those parts of the rods which are directed
towards the fibres of the optic nerve are thicker and terminate abruptly (PI. XXI. fig. 4),
bearing at the other extremity a long and filamentary appendage; while in other
preparations the retina elements which I isolated show the form figured in Plate XXI.
fig. 5,_viz., rods which imperceptibly pass into thread-hke appendages. In these
retinal elements I failed to observe any trace of the presence of nuclei. The thread-
like appendages of the rods extend tiU they reach the cuticular lens. A prajretinal
lamella, which, according to Graber, is characteristic of the stemma of the tracheate
Arthropods is not visible. Between the rod-forming elements numerous ganglion ceUs
are observed in the form of distinct rounded ceUs. I did not observe whether or not
they were really in connection with the filamentary appendages of the rods ; but having
isolated from one of the preparations the rods, as figured in fig. 5, I found that the rod
passes into the filamentary appendage. Probably the gangUon ceUs have also fila-
mentary appendages, which pass between the filaments of the rods. In this respect
therefore my opinion is intermediate to those of Grenacher and Graber. This structure
is observed when the section passes verticaUy through about the middle of the eye

1 Gral^er, V.— Ueber das imicomeale Tracheaten-imd speciell das Arachnoideen-und Myiiopoden-Aiige. Archiv.
f. Miki. Anatomic. XVII. 1880, p. 58-93, PI. v.-ni.

124 THE VOYAGE OF H.M.S. CHALLENGER.

(PI. XXI. fig. 3). When the same (tangential) section passes through the lateral part
of the eye another structure is observed (PL XXL fig. 2), viz., a mass of reticular tissue,
with numerous ganglion cells in its meshes, not unlike but a little smaller than those
between the rods of the retina. Empty cavities, from which, perhaps, ganglion cells
have cbopped, are observed in it. A horizontal section of one of the eyes of Nymiihon
stromii (PI. XXI. fig. 1) shows the arrangement of these parts in the interior of the
eye. The middle part is that occupied by the retinal rods, which here have large
ganglion cells at their extremities, and a distinct mass of reticular tissue, separated
from the retinal rods by a thin membrane (?), is observed laterally. The dimen-
sions of the ganglion cells placed in the meshes of this reticular tissue in NympJion
hrachyrhynchus are almost the same as those observed between the retinal rods ; but in
Nymphon stromii the ganglion cells which are found at the extremities of the retinal rods
are much larger. In regard to the minute structure of these ganglion cells I have hardly
any observations worthy of being mentioned. The cells are always furnished with a
distinct nucleus, and their contents, as a rule, are granular. Those I observed between
the rods of Nymiyhon brachyrhynchus are furnished with one filament directed towards
the lens.

The conclusions I have arrived at with regard to the anatomy of the organs of vision
in the Challenger Pycnogonids may be summarised as follows : —

(1.) A vitreous body, developed out of the cuticular epithelium (hypodermis), does
not exist.

(2.) The epithelium ceUs are present under the lens of the eyes in the same
condition as under the cuticula in general.

(3.) The retina consists of distinct rods and ganglion cells. Numerous ganglion cells,
placed in the meshes of a reticular tissue, form a mass, which encloses the interior of the
eye occupied by the rods.

(4.) The ends of the retinal rods reach the cuticular lens. A prgeretinal interlamella
seems not to exist.

(5.) The retinal rods can not be considered as having resulted from transformed
hypodermic cells.

(6.) The retinal rods have two parts — an innermost thicker part and a filamentary
appendage.

(7.) The eye is surrounded by a chitinous cuticula.

4. Alimentary Canal and its Appendages. — I only occasionally got preparations of
the alimentary canal ; therefore what I have observed in regard to this organ is far
from exhaustive.

Physiologically, this is perhaps the most interesting organ of all, and, morphologi-
cally, its signification is by no means small, as its structure has, along with the number

EEPORT ON THE PYCNOGONIDA.

125

of the legs, always been considered as a very important support for the beliel m the
near relationship between the Pycnogonida and the Arachnida, and more especiaUy
the Phalaugida.

MorphologicaUy, the oesophagus extends from the mouth to behind the oesophageal
commissures. Taking the function of the organs into consideration, I beUeve that only an
extremely smaU part should bear the name of oesophagus. At a very short cUstance from
the mouth the oesophagus widens considerably. This '^ddened part, which shows its
greatest dilatation in front of the midcUe of the proboscis, slopes again backwards, and
imperceptibly passes over into a much narrower canal, which extends immediately
behind the oesophageal commissures. The widened part of the oesophagus, which ahnost
reaches to the end of the proboscis, is invested by a chitinous wall. This wall is beauti-
fuUy beset with thin paraUel chitinous bands, which are furnished with numerous thin
spines. In the front part these are wanting. They begin on the two ventral parts of the
inside a little before they are found on the dorsal part. These foremost spines have the
form of short teeth, and only further back do they assume the form of long thin spines
or needles. From the wall of this part of the oesophagus numerous bundles of trans-
versely striated muscles extend till they reach the outer wall of the proboscis, their
distribution being in Nymphon, e.g., such that two longitudinal rows are attached
to each of the three parts of which the inner waU of the oesophagus is composed
(PI. XVIII. fig. 9). As to the function of this part of the oesophagus, judging from
these muscles and from its internal armature, I think it not very hazardous to com-
pare it with the cardiac portion of the stomach of the Crayfish. It is a masticating

apparatus.

Posteriorly it passes over into a very long (slender species of Nymphon), or rather
short {Colossendeis) cylindrical tube, the wall of which is still divided into three longi-
tudinal parts, which on a transverse section are triangular and leave an extremely narrow
canal in their midcUe. I stucUed the histological structure of this part of the wall, which
extends to beyond the oesophageal commissures. Its cells are of a long cyhncbical form,
longer in the middle and shorter on both sides of the triangular part. They are fui-nished
with distinct nuclei, which sometimes are all placed near the outwardly dii-ected extremity
of these cells, but sometimes also are found more in the middle. Between these cylin-
drical cells there are some of a long conical shape, the base of the cones being, as a rule,
directed outwards. Inside, the surface of these cells is invested by a structureless membrana
intima, and outside a similar cuticular formation is present (PI. XXI. fig. 6). This
epithelial covering does not end abruptly immediately behind the oesophageal commissures.
In the interior of the succeeding part of the intestine it forms three glandular bodies,
which hitherto have not been observed, and whose function, judging from their position,
must be, I believe, pancreatic. In fig. 7 on Plate XXI. I show the place occupied by these
glands, and in fig. 8 of the same plate a transverse section near the extremity of the two

126 THE VOYAGE OF H.M.S. CHALLENGEE.

undermost glands is figured. These glands project into the interior of the intestine, and
are, as far as I know, the only true glandular bodies which stand in connection with the
alimentary canal. They are invested by the same membrana intima as the wall of that
part of the oesophagus, at the end of which they are found. The form of the cells which
compose them is nearly the same. The whole of the gland must be considered as having
taken its origin from an excrescence and bending towards the wall of the intestine, of the
hinder part of that cesoj^hagus.

In regard to the structure of the remaining part of the intestine I do not ■ftdsh to
enter into any details. I only observed that the structiu'e of the wall of that part which
follows immediately after the oesophagus, and of the cseca, which penetrate as a rule
as far as the sixth joint of the leg, is nearly the same. We find this wall everywhere beset
with extremely numerous tubes or villi, which in some genera (^Nymphon) are of a
shorter and more rounded form, and in others [Colossendeis) are very slender and almost
cyhndrical. While the outermost part of the wall is formed of a single row of large
distinct nucleated cells, these vdli show a multi-cellular structure also. Each of these
cells contains numerous globules, which for the most part seem to be of a fatty
nature. The form of the cells is different, but they are commonly rounded. I call
them cells, because each of the bodies has a distinct oval nucleus with a small nucleolus.
As has been observed by almost all authors writing on the structure of the wall of the
intestine, these cells often become detached from the wall, and are found lying loose in
the contents of the alimentary canal. The nuclei in the cells of these villi were by no
means easily observed in all the sections I studied. They were very distinct in the cells
of the villi of Colossendeis prohoscidea, Sab. (sp.).

It seems to be characteristic of the genus Colossendeis that the cteca destined
for the different legs should branch off from the main duct, which runs straight from the
proboscis to the abdomen, very close to one another, and close also to the place where the
oesophagus communicates with the intestine ; at least I observed that in the three species
of Colossendeis I studied (PI. XVII. fig. 1). The number of lateral caeca given
off at both sides of the main duct is six in Colossendeis. Of these the first two are
rudimentary, one being the rudiment of those destined for the mandibles, the other (the
first lateral pair) being that for the proboscis. Each of the four remaining cseca, of
which the hindermost pass through a much longer part of the body before penetrating the
leg than do the more anterior ones, shows a considerable swelling in the lateral processes,
at the ends of which the legs are inserted.^ The anal aperture of Colossendeis (PI. XVII.
fig. Id) is an oval-shaped slit. It is not placed terminally or in the median line of the
abdomen, but laterally.

1 Ou a transverse secti(5n of the body of a Colossendeis between the lateral processes for the .second and for the
third pair of legs, five round sections of the intestine are seen placed close to one another. This furnishes a good
opportunity of comparing tlieir structure, but no difference is observed. Compare fig. 14 of Plate XXI.

EEPORT ON THE PYCNOGONIDA. 127

In Nymjylion, the uumber of lateral casca of the alimentary canal is five pairs. Of
these the first j)air is very wide and directed forwards. At the base of the proboscis
it divides into two branches. One (the larger one) is directed upwards and forwards,
and penetrates the mandibles ; the other one enters the proboscis and divides, in some
species {Nymphon brachyrhynchus, e.g.), again into two branches. These extend in some
species farther than in others, but I never observed them beyond the hindermost half of
its lengjth.'

The groups of comparatively large cells with very thin walls and distinct nuclei, each
of them containing, as a rule, one (sometimes more) strongly refracting granule probably
have also some relation to nutritive functions. These I observed in Nymiilion, Phoxi-
chiliclium pilosum, and in Colossendeis, collected in large groups sometimes about fifty
in number. They seem not to be limited to any particular part of the l^ody, Ijut I
found them always in the neighbourhood of the muscles, between the connective tissue,
where fibrous threads keep them in place. I feel inclined to consider them as analogous
to the fat-cells of most Arthropods. I figure a group of them in PI. XXI. fig. 9.

5. The Circulatory Apparatus. — The somatic cavity is divided into distinct compart-
ments, by means of sheets and bands of fibrous tissue. One of these, placed between the
dorsal wall of the intestine and the dorsal integument of the body, is furnished with
contractile walls, and has the function and the structure of a heart. In Colossendeis this
heart is not surrounded by a pericardial sinus (PI. XXI. fig. 14, li, PI. XVII. fig. 1). The
blood, entering the apertures of the heart, comes directly from one of the longitudinal
compartments into which the somatic cavity is divided. The contractile walls of the heart
do not enclose it on all sides ; for on the dorsal side a part of the integument is used to
form the dorsal wall of the heart. The contractility of these walls is due to the presence
of muscles, which run in a transverse direction and are not striated. Along both sides
of the heart these muscles are inserted into the dorsal integument of the body. As
to their structure, I observed their fibres to be extremely thin and slender. When
studying them with a strong lens {e.g. ,11, Immersion of Hartnack) I observed that they
exhibit parallel edges only for a certain distance ; for this parallelism almost imperceptibly
passes over into an extremely feeble swelling of the fibre, in the interior of which a
long nucleus with a distinct nucleolus is observed.

The heart of the Pycnogonids, as a rule,^ is furnished with three pairs of apertures.

' In one specimen of Nymphon hrachyrhynchiis I observed that one of the branches penetrating the proboscis
lUvided again, so that in the same section, through about the middle of the proboscis, five sections of intestinal cfeca
were observed. This I consider of no importance at all. It only jjroves, I believe, that it is almost dangerous to
attribute any fundamental value to the number of pairs of caeca arising from the intestine. In a large specimen of
Pycnogonum litorale a section of the fourth joint of the leg shows two sections of caeca in the same joint : the csecum
has given off a branch. ConBequently I believe that the number of these branches depends in general upon the capacity
of the ditferent appendages. In Nymphon and Colossendeis no Cceca are observed entering the palpi and the ovigerous
legs, only because the capacity of these extremities does not allow of it.

^ Not always. Fallene brevirostris, Johnston, e.g., has only two of these.

128 THE VOYAGE OF H.M.S. CHALLENGER.

The first pair are placed on the sides of the heart oj^posite to the second pair of legs ;
the second pair are placed similarly, but opposite to the third pair of legs ; the
third pair are found near one another at the posterior extremity of the heart. Through
these three pairs the l:)lood is admitted into the heart/ while it leaves it through a large
opening placed at its anterior extremity. No aorta or arteries arise from it. In the
heart of the specimens in sjairits of Nijmjyhon rohiistum and some other species I
observed a com23act mass of blood-plasm, which so totally filled up the cavity of the
heart as to give, after having been taken out, an exact figure of its form.

As to the blood-corpuscles I only observed that they are, in Nymphon and Colos-
sendeis, round and flat bodies with a distinct nucleus. However, I observed also more
irregularly-shaped fusiform bodies, especially numerous in the cavities of the skin of
Colossendeis (PL XVIII. fig. 1). With regard to their shape and dimensions there is no
great conformity between the opinions of Cavanna and Dohrn ; however, it is only the
study of fresh material that can finally settle such controversies.^

6. Genital Organs. — About the testis of the Pycnogonids hardly anything is known ;
and this cannot be wondered at when one considers that the true males were only dis-
covered by Cavanna in the year 1875, the animals with swollen thighs described as males
before that period being really the females. However, even Cavanna does not seem to have
correctly identified the male organs, for he places them in the fourth joint of the legs.
Dohrn has been the first, and hitherto the only one, who has pointed out the true position
occupied by the testis, " Die Hoden liegen im Korper der Pycnogoniden, nicht in den
Beinen, und bilden dort jederseits einen Schlauch, welcher in jede Extremitat seiner
Seite einen kleineren Schlauch absendet, der an der obenerwahnten Stelle in einer runden
Oeffnung endet." This description, true in the main, is, however, not applicable to all
the species of Pycnogonids ; for, from what I have observed myself, I am able to furnish
full evidence that, for some species, Dohrn's description is not c[uite correct.

A large specimen of a male Colossendeis prohoscidea, figured of the natural size in
Plate XXI. fig. 10, has been opened on the dorsal side. The skin with the heart being
removed, the testis is observed in situ, and the intestine may be distinguished below
it ; the male organ, therefore, is placed rather at the dorsal side of the body.

The two laterally and longitudinally running parts of the organ are united posteriorly

1 From observations I made, in the summer of 1880, in the laboratory of Prof. Lacaze-Duthiers at Roscoflf.

^ Cavanna calls them " piccolissimi globuli ellitici o sobellitticL" Dohrn, on the other hand, describes the blood-
corpuscles as " ungewohnlich gross imd complicii-t." According to Dohrn, there are two forms of blood-corpuscles — "die
einen bilden einen blassen, suzammengefalteten Ballon, in dem ein etwas glanzenderer linsenfomiiger Kern sich findet
nel)en 3^ grossen Vacuolen ; die anderen sind deutliche Amoben, mit lebhaften amoboiden Bewegimgen und
umschliessen oder tragen eine griissere Anzahl glanzender Trdpfchen." It seems to me that the lai'ge balloon-forming
elements come very near to my fat cells (see p. 127) ; and as to the amoeboid corpuscles, these are probably my fusiform
elements and the elliptic ones of Cavanna. If Dohrn is right about his large blood elements, then the animals must
have stUl others of a third form.

EEPORT ON THE PYCNOGONIDA. 129

by a commissure, so there is only one true testis, which has the form of a capital U.
From the upstrokes of this U, on both sides, those parts originate which penetrate
the leg, and which extend almost to the end of the fourth joint. The two jaarts of the
testis which run longitudinally through the body are broad and fiat ; their course is not
straight but rather undulated, being bent outwards whenever a lateral branch takes its
origin. Although the organ is placed at the dorsal side of the body and legs, the
male genital pores are situated ventrally towards the end of the second joint of each leg.
This external opening is very small and is at the tip of a distinct conical tubercle. It
leads into a canal which runs backwards almost parallel with the margin at the distal
extremity of the joint and closely adheres to its chitinous covering ; this canal runs
along the wall of the joint till it reaches the dorsal side of the leg, here it becomes wider
and turns inwards tdl it reaches the testis, which shows a small knob facing the beginning
of the canal. Plate XXI. fig. 11, shows these particulars; the joint is figured as trans-
parent, and the muscles which run from this to the following joint are to be considered
as removed. The outer part of the canal, from the opening for about one-fourth of its
length, is furnished with a thicker wall, and this shows most probably the extent to
which the chitinous covering of the leg is bent inward. The remainder of the canal
is formed of connective tissue, — at least I failed to observe an endothelial covering, —
lined externally by a distinct muscular layer, the fibres of which run longitudinally
and are not striated (PL XXI. fig. 13).

As seen in fig. 2, Plate XVIIL, that part of the testis which penetrates the leg is in a
transverse section kidney-shaped ; a longitudinal duct is formed between the gland and
the thin tissue or membrane which it touches laterally at two points. Most probably it
is with the duct so formed that the canal which opens at the distal extremity of the
second joint is in communication.

I have observed nearly the same structure of the male genital organs in the
extremely transparent species of Nymphon, to which I have given the name of Nymphon
perlucidum (p. 50 of this paper), and also in Nymphon robustum, BeU. Both species
show genital pores in the male sex, only on the two hindmost legs ; and quite in cor-
respondence with this observation only two pairs of lateral excrescences of the U-shaped
testis are to be seen. So when Dohrn says, for Pycnogonids in general, that the male
organs penetrate each leg and open in a round pore on the ventral side (which is,
no doubt, the case in all the species examined by him), he is laying down a
rule which admits of a great many exceptions ; for among the Pycnogonids dredged
by H.M.S. Challenger there are species having their male genital pores only on the
two hindmost legs ; again, there are some which possess them on the three hindmost
pail" of legs, and, finally, there are species with pores on all the legs. My doubts about
this point were cleared up by the observation of those species which bear their male
genital pores at the tip of a stout cylindrical outgrowth (species of Ainmothea, e.g.).

(ZOOL. CHALL. EXP. PAKT. X. 1881.) K 17

130 THE VOYAGE OF H.M.S. CHALLENGER.

Of course the non-existence of a hardly distinguishable structure cannot be con-
sidered proved merely because the structure has not been observed, even in numerous
specimens of the same species. But, on the other hand, if the structure is very
easily seen in some specimens, we are at liberty to conclude that it is absent in those
cases where it was not observed. Moreover, it is hardly possible that in those
cases where the pores are only observed on the two hindmost legs, they should be
present also on the foremost, and from some unknown circumstance should continually
escape observation.'

In regard to the microscopical structure of the testis I have not much to say. On a
transverse section numerous extremely minute cells are observed (see PI. XXI. fig. 12),
while that part of the testis which adjoins the longitudinal canal has lost its cellular
structure, and shows a rather granular condition. Whether these granules are the sper-
matozoa, or whether the numerous globular bodies each furnished with a filamentary
appendage on one side which I once observed, when pulling to pieces with needles a part
of the testis, are the spermatozoa, cannot, of course, be ascertained from animals in
alcohol, even when preserved so well as the Challenger specimens are. Only in mature
animals do the male organs attain the development figured for Colossendeis prohoscidea.
This, most probably, is only the case during a short period of the year, considering
moreover that the males in most species seem to be less numerous than the females
(ten female Colossendeis 2^'>'ohoscidea and only one male, twelve female Colossendeis
lei^torhynchus, and only one male, &c.), it cannot be wondered at that the number of
species in which I could investigate these organs was limited. Except in Colossendeis
prohoscidea, and in three species of Nymp)hon, I observed the testis also in the
leg of Ascorhynchtis glaher (PI. XVI. fig. 9, n), but here only in the fourth joint of
the leg.

In the other specimens which I consider as males, the only means I had to make
out the sex consisted in looking for external sexual characteristics, such as are afi"orded
by the dimensions of the genital pores and the condition of the thighs. Large genital
pores and swollen thighs are characteristic of the females ; slender thighs and smaU
pores, very often not present in the first or in the first two pairs of legs, are characteristic
of the males. Moreover, a transverse section of the thigh of one of the legs is easily
made, and does no injury worth mentioning to the specimen. When in such a section
no ovary is observed, so far as my experience goes, it is almost certain that the

I The genital pores of Nymphon robustum, Bell, (J, are tolerably large, and are easily observed with the aid of a
magnifying glass. Yet I have examined large specimens of this species (dredged in the Barents Sea), where these pores
were not observed, even when investigating the joints with the microscope. As I was convinced of the exactness of
this observation, I felt greatly puzzled with it at first ; afterwards on reading a paper of Schobl in the Archiv f. Mikro-
skop. Anatomie, Bd. xvii., 1880 (Ueber die Fortpflanzung isopoder Crustaceen) I found that this author admits that in
the females of these Crustaceans, the genital pores are only present at a certain period, and are totally wanting during
the rest of the year. Perhaps there are male Pycnogonids which have the same peculiarity.

EEPOET ON THE PYCNOGONIDA. 131

specimen is a male ; even in very young females at least a trace of the ovary is always
to be observed in those joints.

According to Dohru the female glands are disposed in the same way as the testis,
with the only difference, that in the ovaries of most species, the lateral excres-
cences which penetrate the legs and often force their way into the penultimate joint,
are the only parts which develop mature eggs.

What I happened to observe agrees almost completely with Dohrn's description.
I perfectly believe, however, that the occurrence of a part of the ovary in the body of a
Pycnogonid is rather rare, because, as a rule, only the lateral excrescences remain.
No doubt this must be considered as a secondary condition ; and seeing that, so far
as I could ascertain, it is the rule in all the species of Nymphon, my original opinion,
that the genus Nymjjhon, of all the genera of Pycnogonida, resembled most the
hy|3othetical ancestors of our group, was severely shaken.

The genus Colossendeis affords a beautiful example of the original condition of the
ovary. I examined a specimen of Colossendeis leptorhynelms, Hoek. A transverse
section of the body showed the place occupied by the ovary, and convinced me of the
exactness of Dohrn's assertion. However, as in the case of the testis, Dohrn's observa-
tion is incomplete in one respect ; there are not two ovaries, but only one. Immediately
in front of the abdomen the two lateral parts are united by a cross-piece, and so the
ovary has the very same shape as the testis, viz., that of a U with long upstrokes.
That it occupies also the same position in the body as is the case with the testis, is clearly
seen in fig. 14, Plate XXL, which is a drawing of a transverse section of the body. In
0. the ovary is shown placed above the intestinal ti'act and its excrescences which pene-
trate the legs. The dimensions of the eggs in that part of the ovary which is situated
in the body are, at least in this species, the same as of those eggs which are found in the
thighs of the legs. The lateral excrescences penetrate all the legs, and in the specimen I
studied reach the sixth joint. This, most probably, will greatly depend on the state of
maturity of the animal. I often found the eggs only in the thigh, but often also {Han-
nonia typica, Hoek, PI. XIV. fig. 11, e.g.) the eggs are found as far as the end of the
second tibial joint. The ovary is always placed dorsally to the intestinal tract, which
is also the case with those animals which have only the lateral excrescences left, and
thus show several ovaries.

The structure and the formation of the ovarian eggs I will describe further on. In
regard to the way in which the eggs are laid, I had the good fortune to observe the
copulation of a male and female Phoxichilus laevis, Grube, when I was, last summer,
in the zoological station of Professor H. de Lacaze-Duthiers at Roscoff. The eggs
are fecundated the moment they are laid, and the copulation, therefore, is quite
external, brought about by the genital openings of the two sexes being placed against
each other. Half an hour after the beginning of copulation, the male had a large

132 THE VOYAGE OF H.M.S. CHALLENGER.

white egg-mass on one of his ovigerous legs, and about one hour later l)oth masses were
present.

The female genital openings are a great deal larger than those of the male, and are of
an ovate shape, and, as a rule, oviducts are totally wanting. I only observed them in
the genus Colossendeis, where they have nearly the same course as the vasa deferentia.
Nearly in the middle of the second coxal joint of the two hind legs a lateral branch
arises from the ovarian ccecum, which passes through the joint. The interior of this
branch, which is the oviduct, is in immediate communication with the ovary, and during
the breeding season the eggs are found penetrating the branch. While the ovarian coeca
which penetrate the legs are lined only by connective tissue, the oviducts which
begin at the dorsal side of the second coxal joint and run along the wall of the joint till
they reach the opening on the ventral side, are lined by a coat of longitudinal muscle fibres.
The female genital opening in this species is small and rather triangular.^

From the end of the oviduct which reaches the opening, distinct muscle fibres
radiate, and are inserted round the opening on the inside of the chitinous wall of
the joint. A transverse section of the fourth joint of the leg of a female Colossendeis
leptorhynchus is figured in fig. 16, Plate XVI. ; m is the ovarian coecum which, as this
specimen is by no means mature, is only of small dimensions ; when in the breeding
season, the whole central cavity (which in the figure is represented as empty) is filled
with eggs ; it .swells to such an extent as to fill up almost the whole cavity of the leg, in
so far as this is not occupied by the intestinal coecum. As in the other species of
Colossendeis, the eggs are extremely numerous and small. Each ovarian egg has a
distinct germinal vesicle, which is placed almost exactly in the centre of the egg, and
has, as a rule, one distinct and very glittering germinal spot. Among the older eggs,
which are richly furnished with yelk, smaller ones are always observed whose protoplasm
is almost quite transparent. Each egg is surrounded by a very thin membrane, which is
a true " vitelline membrane " and adheres closely to the protoplasm of the egg.

In the genus Nymphon, I have investigated the female genital organs of the follow-
ing species : — Nymphon hrevicmidatum, Miers ; N. hrachyrhynclms, Hoek ; N. robustum,
Bell ; N. longicoxa, Hoek ; and N. hamatum, Hoek. I never observed the ovary in
the body of these species, and always found at least a trace of it in the fourth joint of
the leg (thigh).

When in an early stage of development, the ovary is placed against and at the dorsal
side of the intestinal ccecum which passes through the joint. While the ripe ova, which
are often very large (PI. XVI. fig. 7 I, ripe ovum of Nymphon hrevicaudatum, Miers),
have a thin vitelline meml^rane as in the ovum of Colossendeis ; younger ova have often the

1 In this si^ecies, as I have mentioned already (p. 63), the genital openings, both in males and females, are present
only on the two hind legs ; at least in all the specimens at my disposition, 1 failed to oljserve them on the first two
pairs of legs. However, ovarian ccBca penetrate the first two pairs of legs as well as the two others.

REPORT ON THE PYCJSTOGONIDA. 133

appearance of being surrounded by a very thick and concentrically stratified membrane
(ovarian egg oi Nymphon brevicaudatum, PL XXI. fig. 15). In other species [Nymphoa
robustum, PL XXI. fig. 16) this membrane is perfectly transparent, while iu both cases
tlie granular protoplasm of the egg within this thick membrane or capsule seems to be
surrounded by its vitelline membrane. In a third case, which I observed in Nymphon
longicoxa (PI. XXI. fig. 17), the membrane of the egg does not seem to be thick, but
irregularly folded and crumpled ; yelk-particles are here very numerous iu the central part
of the egg, which surrounds the germinal vesicle ; and the protoplasm of the egg extends
beyond this central part till it reaches the crumpled membrane. However, it is very
probable that the condition of the eggs has suffered from their having been so long in
alcohol, only I wish to point out that from what I observed it is almost certain that
any one studjdug the formation and the development of the animal egg, will find a very
interesting ol^ject in the egg of the Pycnogonida. The dimensions of the mature ova
are very different. Of the specimens I studied they are largest in Nymphon longicoxa,
N. brevicaudatum, and N. robitshim, a great deal smaller iu N. brachyrhynchus and
N. hamatum (the number of eggs united in an egg-mass being always in inverse propor-
tion to their size).

While in the younger ovarian eggs the germinal vesicles as a rule are placed in the
centre of the egg, in the very large mature egg the vesicle is placed close to the wall.
Sometimes {Nymphon longicoxa) it has the shape of a sand-glass, and once I observed an
extremely small micropyle canal in the membrane of the egg, just opposite the place
occupied by the germinal vesicle. As a rule there is only one germinal spot, Imt I once
observed two distinct spots in the germinal vesicle of the egg of Nymphon longicoxa. In
the ovarian egg of Nymphon robustum one distinct nucleolus may be observed almost
exactly in the centre of the rounded and granular germinal spot. As for the manner
in which the eggs make their way to the genital apertures in those cases in which no
true oviduct is observed, I think there can be no doubt that the body-cavity itself per-
forms the function of an oviduct. The absence of such a duct at the genital pores,
and the fact that I repeatedly observed detached eggs pressed against the connective
tissue surrounding the ventral ganglia or other parts in the interior of the body admits
of no doubt in this respect.

All I have said about the ovary and the formation of the ova in the genus Nymphon
also holds good in the case of the other genera. The limited quantity of specimens
prevented me from making a section of the l^ody of species of these genera. Most
probably Ascorchynchits will show the same disposition as Colossendeis. A transverse
section of the thigh of one of the legs of Ascorchynchus orthorhynchus is figured in
Plate XVI. fig. 11. The thigh is much more dilated than one of the other joints of the
leg, yet it is not round but flattened, and the contents are almost divided into two un-
equal parts by the large chitinous thickening, which at the one side is in connectio^

-4

134 THE VOYAGE OF H.M.S. CHALLENGER.

with the wall of the leg. The one part is filled up with the ovary, the other partlj- with
the coeeum of the intestine. The ovarian eggs are small and are furnished with a
central germinal vesicle. Most probably the females of the species of Ascorhynchus have
an oviduct like that of the species of Colossendeis. The species of Pcdlene show the same
disjjosition as in Nymphon. A transverse section of the thigh of Pcdlene australiensis
corresponds perfectly with that of Nymphon hrevicaudatum, figured in Plate XVI.
fig. 7 ; there is one very large and probably mature egg with an eccentric germinal
vesicle, and numerous smaller ovarian eggs, with their vesicle in the centre. Moreover,
minute researches on Pcdlene hrevirostris (an inhabitant of the Dutch coast) admit of no
douljt as to the structure of the ovaries ; they are totally wanting in the body, and take
their origin in the thighs of the legs. The eggs when mature are large, and their number
is limited.

In the genus Phoxichilidimn I studied the anatomy of the body of Phoxichilidium
pdosum (a female specimen) without meeting with the. ovary. In the legs of this
species, however, and also of PhoxichUidium patagonicum, I soon found it. The
whole cavity of the leg is often filled up with eggs, and these are even observed
pressed closely against the wall of the leg (PI. XVI. fig. 17). The eggs are comparatively
small and very numerous. The membrane of the eggs is much thicker than is the case
with the eggs of the other genera (PI. XXI. fig. 18). Neither in the species of Pcdlene
nor of Phoxichilidium did I observe the least trace of an oviduct, so I think that here,
as in Nymphon, the genital aperture communicates directly with the cavity of the leg.
I think also that the circumstance I often observed of eggs free in the cavity of the
leg is in suj^port of this opinion (PI. XXI. fig. 18). For the other genera of Pycnogonids
I have, so far as the ovaries are concerned, no observations worth mentioning.

7. Observations on the Embryology of the Pycnogonida. — Among the Pycnogonids of
the Challenger Expedition there were some sj^ecies provided with eggs. On account of
the great importance of embryology for the study of the aftinities of a group of animals
I tried to acquire as much information on this subject as possible. Unfortunately, with
the exception of one species belonging to the genus Ascorhynchus, G. 0. Sars, all the
species with egg-masses belong to the genus Nymphon, Fabr., but of these there are out
of twelve species no less than six provided with eggs.

The researches of Kroyer, Johnston, Goodsir, Dohru, Semper, Cavanna, and myself,
have shown that in the genera Pycnogonum, Pcdlene, Phoxichilus, Phoxichilidium,
Nymphon, &c., the eggs after having been laid are carried on the so-called ovigerous
legs. The honour of having discovered that not the females (as was believed by the
older authors) but the males fulfil the duty of bearing these eggs is due to Cavanna ; this
observation has since been confirmed by the researches of Dohrn, Bohm, and myself.^

' The observations of Cavanna were published in the year 1875. It is indeed strange to see that neither Wilson
nor Miers have heard of this discoverj'. These authors, in their descriptions of new species, &c., are therefore ahnost
constantly confounding the two sexes.

REPORT ON THE PYCNOGONIDA. 135

In the first place, however, I wish to draw special attention to the fact that with regard
to Nymphon hrevicaudatmn, Miers, this rule admits of an exception. I examined a species
with large genital pores and swollen thighs, and provided with egg-masses on the ovi-
gerous legs. On investigating transverse sections of the thighs, I soon saw that this
specimen was a female. So far as I know, this is the first time that an exception to
this rule has been observed. In the second place, I wish in a few words to discuss
the circumstance that, although eight different species of the genus Colossendeis were
collected (together represented by thii"ty-one specimens, and four specimens of Colos-
sendeis proboscidea, Sab. (sp.), trawled north of Scotland during the cruise of the
" Knight Errant "), none of these are provided with eggs. The number of males, however,
is very restricted : there is only one male Colossendeis leptorhynchus among nine speci-
mens, there is one male Colossendeis gigas among six specimens, one male Colossendeis
megcdonyx among seven, and, finally, one male Colossendeis hrevipes. On the other hand
it is possible that the genus Colossendeis is an exception to the rule, and that the males
in this genus may not have the gallantry to nurse their babies as the males of the species
of other genera are accustomed to do. For, comparing the ovigerous legs of the males
with those of the females, a distinct difference is almost always easily observed : those of
the males are a great deal stouter, the fifth joint is as a rule swollen towards the
extremity, or furnished with a distinct knob, &c. ; but in the ovigerous legs of the
males of the species of Colossendeis, these differences in form and size are never observed.
So it is quite possible that they deal diff'erently with their eggs from the species of
other genera.

The species provided with eggs are: Nymphon hamatum, Hoek ; N. longicoxa, Hoek ;
N. fuscum, Hoek ; N. brevicoUum, Hoek ; N. brachyrhynchus, Hoek ; N. brevicau-
datum, Miers ; and Ascorhynchus minutus, Hoek. Of the latter species there are in
all two specimens, and of these one bears eggs. But the development of these eggs is
in its last stage, so that I was only able to ascertain the form of the larvae. The eggs of
this species are extremely small, and at the same time numerous.

It consequently happened that my embryological researches were limited to the genus
Nymphon ; in so far not unfavourable, as yet almost nothing has been published on the
embryology of this genus.

Full-grown males of the genus Nymphon bear the eggs on the fourth and fifth joints
of the ovigerous leg, or only on the fifth joint ; the cvxrious foliaceous appendages occur
on the sixth to the tenth joints of the leg, and have nothing to do with the egg-bearing
function of the leg. Yet it is i^ossible that they may be of some use in seizing the eggs
when just laid, but, on the other hand it must be observed, that in the genera where
these apj)endages occur, the ovigerous legs of the females are furnished with them as
well as those of the males.

The eggs are soldered together and form in the species of Nymphon I studied, and

136 THE VOYAGE OF H.M.S. CHALLENGER.

in Ascorhynchiis miniitus, one packet only on each ovigerous leg. I lielieve, however,
that cases are by no means rare in which two or even three packets are formed on one
ovigerous leg. The packet is placed round the leg, and in some species {Nymiihoii
hrachyrhynchus, Hoek, e.g., PL XIX. fig. 1), it may be easily brushed off. In other
species, however, Nymphon robustum, Bell, for example, this is by no means so easy, the
surface of the joints of the ovigerous legs being furnished with numerous hook-like
spines.

Every egg in the packet has its own membrane, a very thin and structureless tunic.
The size of the packets is very different. It varies greatly with the size of the animal,
but is different also in diflerent specimens of the same species. The size of the egg
seems to be constant for CA'^ery species ; consequently the size of the packet will depend
on the number of eggs in each j)acket ; and the age and the condition of the female will,
of course, influence this.

The egg of Nym2)hon brevicaudatum , Miers, measures 0'5 or 0'7 mm. ; when in the
first stages of development it is nearly globular (0'6 x 0"6 mm.), afterwards oval (0'5 x 0"7
mm.). The number of eggs in each packet varies between fifty and sixty. The egg
of Nymphon fuscum is a great deal smaller (0"15 or 0"12 mm. The eggs oi Nymphon
hrachyrhynchus are about 0'55 mm. and even in a much advanced stage of development
nearly globular. Large packets of the latter species do not contain more than fifty eggs,
and the dimensions of these packets vary between 3"14 x 1'85 mm. and 2"3 x 1'6 mm.
The egg of Nymp)hon brevicoU a ni has a diameter of 0"2G mm.; the number of eggs in a
packet is in this species about ninety. Fig. 2 on Plate XIX. gives a section of a
packet of eggs of this species. The colours are those which are seen when the
object is coloured with picrocarmine, and the figure is half in outline ; every egg is seen
to be placed in a cavity formed by the cement which solders the eggs together (c), and
coloured distinctly red by the picrocarmine. The large opening (o) in the centre is
that occupied by the ovigerous leg ; the small holes {s, s) are those which are left between
the eggs when soldered together. On the outside mud and sand particles adhere to the
packet (m).

So far as I know, Dohrn is the only author who has published observations on the
cleavage of the Pycnogouid egg ; ^ but as the method of making sections of such very
small eggs was not yet in use when he published his paper, and could not, therefore,
he applied by him, I might reasonal^ly have expected to see much more than he did, by
availing myself of this method of recent embryology. Yet my researches in this respect
were not very successful, owing at least partly, I believe, to the condition of the material
I studied. Ever)^ one will acknowledge how necessary it is, especially in embryological
researches, to study fresh and also very rich material ; now the Challenger Pycnogonids
had been six or seven years in alcohol before I studied their eggs, and, moreover, the

' A. Dolirn, Ueljer Entwicklung unci Ban tier Pycnogoniden, Jenaische Zeitschrift, Bd. v., 1869.

REPORT ON THE PYCNOGONIDA. 137

quantity was limited, so I need not appeal to the indulgence of the reader on account
of the imperfection of my researches in this department.

The study of the eggs of Nymphon Irevicaudatum, Miers, was the most successful of
all. These eggs are the largest of the species here in question ; the number of animals
furnished with eggs was in this species rather gi-eat ;' aud their condition was superior
to that of the eggs of the other species. The method I followed is weU known. I
enclosed the eggs (hardened with absolute alcohol) in paraffine, and coloured the sections
afterwards with picrocarmine.

Fig. 3 is a cba^dng of the first stage I was able to observe. The food-yolk and the
formative-yolk (deuto- and proto-plasma, Ed. van Beneden) are still mixed together, and
the cleavage is complete. Eveiy segment is furnished with a nucleus, coloured cUstmctly
red by the picrocarmine, and situated ahnost in the middle of each segment. The structure
of the yolk particles in each segment is very curious, and probably this is caused by
the continued action of the alcohol. In fig. 4 I give a strongly-magnified drawing of a
small part of such a segment just at the border of the section. It looks as if the yolk-
elements had grown vesicular,— a inatter I only make mention of as the same structure
is no longer observed in the next stage of development of the egg. In this stage, as in
the foUowing, the egg is furnished with a distinct but very thin membrane.'

The second stage I observed has the blastoderm distinctly developed. The cells of
which- it is composed are very much flattened, and do not show distinct limits ; a very
large nucleus is, on the contrary, always easily observed. Fig. 5 shows the cells as seen
on section, fig. 6, the blastoderm with the nuclei magnified. Every nucleus shows a
distinct nucleolus and numerous small granules. In this stage the food-yolk is irregu-
larly spUt into larger or smaUer parts, which are coloured yellow by the picrocarmine ;
they do not show the vesicular structure of the yolk-segments in the first stage, and are
not furnished with a nucleus.

A transverse section of the next stage of development I observed is figured in fig. 7.'
Here the embryonic development is already far advanced, consequently I was nof able

I The eggs oiNymplwn harmtum, N. lonyicoxa, and N. Mum were so far advanced in development that in them
onlv the different larval stages coiild be studied. , , , i

^ Dohm loc. cit, p. 139, says that the egg of Pycnogmum litorale has a double membrane, and that these membranes
are found in the ovary, an assertion not corresponding with the observations I made on the eggs of Nymphon.

3 Between the sUvge figured in fig. 7 and the foregoing, nimierous other stages were observed ; but m these the cel-
lular structure was so totally . spoiled by the action of the alcohol, that I dare not give drawings or descr.pUons
of them. The only means of distinguishing the embryonic cells from the deutoplasm is by the colouring of the
cells mth picrocarmine, and there can be little doubt that one of the first changes the blastoderm undei^^oes con-
i irthe'formation o'f a longitudinal thickening of it at the future ventral side of the embrya This Inckemng
terminates rather abruptly at the anterior end, but at the posterior end it slopes graduaUy to the imicellular_ part
S™ e b astoderm. Afterwards a longitudinal furrow seems to take rise in the middle of this thickemng, the inner
part of which is finally isolated in the form of a longitu.linal tube. I publish these details only with the strongest
reserve, the condition of the eggs and the circximstance that the sections are necessanly taken in quite xmcertam
directions, making the giving of a decided description impossible.
(ZOQL. CHALL. EXP. — PART X. — 1881.)

138 THE VOYAGE OF H.M.S. CHALLENGER.

to study the formation of the germ-layers, nor the modifications which they undergo
durino; development. Whether all the cells of the embryo in this stage are derived
exclusively from the blastoderm, or whether they are also partly due to the deutoplasm is
a question which it is impossible to answer from the section before me. Dorsally the
greater part of the embryo is- covered by a single row of flatten.ed cells (the original
blastoderm cells), ventrally a plate is clearly distinguished much thicker than the blasto-
derm, and doubtless formed of cells more than one row deep. Unfortunately, however,
the limits of these cells were quite gone ; I therefore could not distinguish either their
number or arrangement, Ixit I believe the evidence is great that in the inner layer of this
plate the original mesoblast is to be seen. In this stage rudiments of the appendages
are distinctly formed ; and I consider it a very characteristic feature in the development
of the Pycnogonids, that the food-yolk penetrates into these appendages. In the section
here figiu^ed, however, that part of the food-yolk which penetrates the leg, is not in direct
connection with the central food-yolk mass ; but this is caused Ijy the circumstance, that
the section does not pass exactly vertically through the embryo, but goes a little obliquely
from above backwards to the ventral side.

The blastoderm shows to a considerable extent in the stage I have figured a double cell-
layer dorsally in the middle, and even a small lumen is observed between these two.
Small cells or nuclei seem to be present in this lumen, and the whole arrangement made
me think it ])Ossil)le that I had an early stage in the development of the heart before
me. The broad and flattened condition of the heart in the adult animal of Nymphon
is not opposed to this suggestion ; yet it is difficult to understand why a heart should be
developed l)efore there seems to be any question of an intestinal tract.

About the same stage is also figured in figs. 9 and 10. At the ventral side the
first pair of appendages (the foot-jaws), three pairs of legs, between the foot-jaws
the proboscis, and the caudal protuberance, are easily distinguished. The second
and third pair of cephalic appendages show in this species a remarkal^le retardation
in their appearance, visible in the stage in which the first and second pair of true
legs are already two-jointed and bent inwards so as to meet in the middle of the
ventral surface, and in which the thii-d pair is longer, yet bent inwards and forwards.
In this same stage the third cephalic appendage is not yet distinguishable, and the
second pa:ir only shows a small protuberance at the base of the foot-jaws. An equatorial
section of an embryo in this same stage is figured in fig. 11. Between the foot-jaws («)
and the first true leg (h) two small protuberances are distinguished, the first of which (c)
is larger than the second {d), which in this stage is observed only interiorly. The
section- is also remarkable for the distinctness with which the nerve ganglia are seen.

There is good reason to consider this arrangement characteristic for the species
Nymphon brevicaudatum, Miers. Other species of Nymphon, of course, may show
the same ; so far as I could ascertain it is not the rule, for neither Nymphon

KEPOET ON THE TYCNOGONTDA. 139

hracht/rhynchus nor N. brevicollitm nor N. hamatum agree with N. hrevicaudatum
in this regard. Fig. 8 shows a stage in the development of Nmnjjhon hrachyrhi/nchvs,
in which the three first pairs of embryonic appendages are akeady present. The first
pair (the largest) are armed Tvith pincers ; the second and third are small, armed with
curved hooks and not taking parts of the food-yolk ; of the true legs in this stage nothing
as yet is to be seen. In figs. 12 and 13 I have figured a larva of Nyniphon hrevicollum
showing the three cephalic appendages, the first pair of true legs almost completely
developed, the second pair much shorter than the first, and not yet furnished with claws,
the third only as a rudimentary process ; the fourth pair is totally wanting in this stage.
Consequently I believe it is the rule in Nyniphon, that the three pair of cephalic
appendages are developed first of all, the legs appearing afterwards in regular succession.

To retui-n to Nymjjhon hrevicaudatum, Miers, in figs. 9 and 10, I have figured embryos
within the shell of the egg almost of the same stage ; with this difference only, that in
fig. 10 the egg is figured as seen from the ventral surface. In fig. 9 also, a part
of the dorsal surface being bent over to the ventral side has been dra'WTi. In this
last figure it is clearly shown that the dorsal surface of the embryo is at least at the
■ anterior side lined with a shell-like thickening, the proboscis and the first pair of cephalic
appendages being at their origin covered by this thickening as by a cap. Near the
anterior side of this cap the double supra-oesophageal ganglion is situated, making it
evident that in the border of this cap the anterior margin of the cephalic part of the
embryo is to be seen ; the proboscis being only an azygous excrescence of that part of
the ventral surface which surrounds' the mouth.

The equatorial section figured in fig. 1 1 shows the distribution of the nerve ganglia
on the ventral surface ; the first and second ganglia ate smaller and are placed close to
each other ; the development of the third, fourth, and fifth ganglia is in near relation with
that of the corresponding legs ; finally, neither the sixth ganglion nor the fourth pair of
legs is to be distinguished. In the middle the two halves of every ganglion are placed
close to each other, which, as far as I could ascertain, is also the case in earlier stages.
Of the longitudinal commissures between the ganglia in this stage, nothing as yet is to be
distinguished, and as to the cellular structure of the ganglia, I was only able to trace
large cells without any difi'erentiation.

The degree of development the larvae have reached when leaving the shell of the egg
is not the same for all the species of Nymphon ; so I think it probable that the larva of
Nymp)hon hrevicaudatum, Miers, does not creep out of the egg before the four true legs
are developed, whereas the young of Nymphon hrevicollum cling to the ovigerous legs
of the father as soon as only one of the pairs of true legs has reached its full development,
and perhaps even earlier yet. So, when Semper affirms that there occurs a complete
metamorphosis in the development of the species of the genus Nymphon, two points
are to be borne in mind, (l) that this does not affect all the species of Nymp)hon in

140 THE VOYAGE OF H.M.S. CHALLENGER.

the same way, and (2) that here the word metamorphosis has quite a different meaning
from what it has in entomology.

Of the genus Nymjyhon I was able to compare the larvas of the species Nymjihon
hrevicollum,, N. hamatum, and N. longicoxa. Of Nymiyhon hrevicollum I have figured
the youngest stage observed in figs. 12 and 13 ; an older one, which has three pairs of
legs fully developed and the fourth already planned in the form of two lateral processes,
has been drawn from the ventral side in fig. 1 of Plate XX.

On the ovigerous legs of the same animal I found together larvae in both the stages I
have figured, and also in intermediate stages. Taking a small number of these larv« from
the leg to study them under the. microscope, I often observed the membranes of earlier stages
between them. These membranes, and especially the parts which belong to the fore-part
of the body, are attached to one another by means of long threads ; these threads take
their origin in the first joint of the foot-jaw, which bears a protuberance perforated by
the thread. In the interior of the joint, and also of the empty membrane of this joint
the thread can be traced a short way, but in neither to a great extent, as in the joint it
is covered by the food-yolk, and in the membrane soon ceases after having passed the
protuberance.

The larvae of Nymplion hamatum which I was able to study were already furnished
with four legs. Their condition was not extremely favourable for minute investigation,
esj^ecially because the food-yolk makes the whole body opaque. The third pair of
cephalic appendages are but small, and have each the form of a two-jointed stump bearing
a pair of small spines at the extremity. The fore-part of the body of this larva is figured
in fig. 3, Plate XX. An apparatus of a very singular shape, and, of course, closely connected
with the protuberance perforated by the long thread in the larva of Nymplion hrevicollum,
is situated as in that species in the first joint of the foot-jaw. Numerous bottle-shaped
sacs are placed near each other, and in such a way that their necks meet in one point.
Each neck terminates in* a small semilunar border, which covers a small slit ; tlu'ough
this slit a thread passes, that can be easily observed as it runs through the throat of the
bottle-shaped sac. The widened part of the bottle has in its interior two or more
vesicles, which seem to be filled with an opaque protoplasm, covering in all probability
the origin of the thread. Every bottle has its own thread, and of these more than ten
are easily counted. I have figured this apparatus in fig. 4, Plate XX. The study of the
apparatus is very difiiciilt, as it is not transparent, being covered at one side by the food-
yolk. The diff'erent bottle-shaped sacs are enclosed in a granular mass, with which
very fine fibres seem to correspond. I could follow these fibres to a certain distance
from the apparatus, where they are covered by the food-yolk ; and from their pale
appearance, and the circumstance that they are not easily coloured by picrocarmine (as
the muscles, fig. 4, are), I felt inclined to look upon them as nerve-fibres.

The same organ, but of a somewhat difierent shape, occurs also in the mandibles of

REPORT ON THE PYCNOGONIDA. 141

tlie larvae of Nymjyhon longkoxa. These larvae in almost every detail correspond with
those of Nijmphon hamatum, but the organ here in question is a curious exception.
I have figured it in fig. 5 of Plate XX. Numerous small vesicles are in close relation
with each other, and are so placed that they seem to radiate from a common centre. The
whole apparatus is small ; fig. 5 shows a drawing enlarged 270 times. The vesicle
corresponds in all probability with a larger one placed in the centre, sending forth the
thread, which in this species is always a single one. The thread is a little swollen at
the foot, and seems (to judge from the double lining under the skin) to run through a
sheath, at the end of which a semilunar border covers a small slit, through which the
thread passes. Of course the chitinous skin of the larva is not coloured by the
picrocarmine, but the broad and flat thread is. This thread is very long, its length
sometimes equalling and even surpassing half the length of the larva ; at a certain
distance from the beginning I repeatedly observed a small part of the old skin, which
remained in relation with the thread, while the larva got a new one.

A similar apparatus to the one described by me for the larvae of Nymjyhon hamatum
and Nymphon longicoxa (and occurring in all probability also in Nymphon brevicollum) has
been observed by Dohrn in the larva of Achelia. The first joint of the mandible bears a
strong spine in the larva. " An diesem letzteren sieht man fast immer einen sehr feinen
Faden befestigt und erkennt bei naherer Untersuchung, dass dieser Faden aus dem Dorn
herauskommt. Der Dorn ist namlich hohl, seine Spitze durchbohrt und im Inneren
sieht man einen zweiten feinen Canal der von einem merkwiirdig gestalteten Organ
ausgeht, das in der Basis des ersten Gliedes der Scheerenfusse liegt. Das Organ hat
die Gestalt eines Kartenherzens, die Spitze ist verlangert in den eben erwahnten Canal,
der anfanglich etwas breiter sich bald verschmalert und quer durch den Innenraum des
Beines sich zu dem Dorn begiebt. Der Canal ist nicht hautig, sondern hornig, dennoch
beugt er sich in massiger Kriimmung, ehe er den Dorn erreicht. Die Structur der
DrUse — denn fiir eine solche muss ich das sonderbare Organ halten — habe ich nicht
ermitteln kdnnen, nur so viel vermag ich anzugeben, dass die hintere Halfte aus kleinen
Zellen bestand, die dem Organ eine gewisse Aehnlichkeit mit einem Nervenganglion ver-
liehen, wahrend die vordere Halfte von zwei merkwiirdigen blassen Flecken eingenommen
wurde, die Kugelgestalt besitzen, aber nicht erkennen liessen, ob sie mit irgend einer
Substanz gefiillt waren, oder Hohlkugeln darstellten. Ueber und unter dieser Driise.
liegen Muskeln, welche zur Bewegung des zweiten Gliedes der Extremitat dienen." ^

There remains no doubt that the organ of Dohrn is the same as that observed by me.
Also, as I already said above, I feel very much inclined to adopt the conjecture about the
character of the organ proposed by him. The organ is a gland, and the product of its
secretion consists of one or more fine threads. These threads occur only in the larval con-
dition, and as for their use I wish to compare them with the byssus threads of the Lamelli-

' Dohru, I. c, p. 141.

142 THE VOYAGE OF H.M.S. CHALLENGER.

Ijranchicata. The larvae of different species, as observed by me, usually remain for a
long time after having cast off their exuvige, in relation to the ovigerous leg of their
parent. As long as they were enclosed in their egg, they clung together tightly enough ;
but once crept out of the egg-shell, a special arrangement is necessary to keep them
together. This is found in the threads, and the supposed glands from which these take
theii' origin, as observed by Dohrn and me. Repeatedly I saw, as I have mentioned
already before, between the larvae of Nymphon hrevicoUum, collections of very numerous
skins held together by means of the threads, and small parts of such a cast skin I found
also in relation with the thread of the larvse of Nymphon longicoxa.

It is true that the structure of the apparatus, as it shows itself in the larva of Nym-
phon hainatuni, argues, perhaps, for the conjecture that the organ is an organ of sense,
but then it is exceedingly strange that such an organ should only be found within the
larvse. And it would be difficult to explain the meaning of the single or numerous long
threads as being sent forth from an organ of sense, whereas in relation with a gland their
function can easily be understood.

The study of this same organ which I made last summer in the laboratory of Prof.
Lacaze-Duthiers, at Roscoff, has also convinced me, that my original supposition as to the
function of these organs was erroneous. The fine threads, which I observed in the
interior of the mandible running towards the organ are threads of connective tissue ;
their function is, no doubt, to hold the organ in its place. The young of Nymphon
rohustum, Bell, and those of Nymphon hrevicaudatmn, Miers, are a great deal more
developed when creeping out of the egg than those of Nymphon hamatum, N. longicoxa, and
N. hrevicoUum. Most probably this spinneret of the larva does not occur in these species.

Besides the larvse of the genus Nymphon, the only other genus of which I could
investigate the larvse was Ascorhynchus. About their development and metamorphosis
nothing as yet has been published. I can only give a drawing of the single larval
stage which I observed, and- which is furnished with three pairs of legs. The fig. 6
on Plate XX. shows that the larva in this stage corresponds with larvse of other genera,
as observed by Kroyer, Dohrn, and myself. Of the glands in the foot-jaw no trace
could be discovered ; but then the larvse are very small, and their condition is not very good.

8. In studying the anatomy of the Pycnogonids of the Challenger Expedition, I met
with two different kinds of bodies of which I have not been able to ascertain whether they
really belong to the organisation of the Pycnogonids, or must be considered as parasites.
However, I feel much inclined to adojrt the latter opinion ; and although some doubt
remains, I wish to give a short description of what I have seen, which may, perhaps,
be of use for later investigators.

In the first place I met with some curiously shaped forms in the interior of the body and
of the legs of two different species of Nymphon. I observed them in Nymp)hon longicoxa
and in Nymphon hrevicaudatmn, but only in some of the specimens which belonged to

REPOET ON THE PYCNOGONIDA. 143

the male as well as to the female sex. They are comparatively large, often long ovate
cells with a thin wall, the contents consisting of large granules and a longitudinal slightly
curved nucleus.

When colouring the preparations with picrocarmine these forms assume a yellow colour,
the nucleus becoming beautifully red. They seem to be distributed through the body very
ii-regularly and seem to penetrate all the cavities accessible to the blood. In Nymphon
brevicaiidatum I even observed them in the space before occupied by the eggs, and in
which still an unripe egg was to be seen. Both in this species and in Nymphon longicoxa
most of these curious forms are very regularly placed against the wall of the leg, where
they often form two or even more distinct layers. Their size varies between 0"066 and
O'OSl mm. With regard to their nature my opinion is not at all a settled one ; but I
am strongly inclined to believe them to be the eggs of some parasitic animal. But what
kind of animal their parent in that case will prove to be I am unable to say.

The other kind of bodies must be regarded, I believe, as ectoparasites of Colossendeis
leptorhynchus. Of the ten specimens of this species in the Challenger collection there are
three which are sprinkled over with these. The one is a male, the two others are female.

They are rounded, sac- forming bodies, often with a crumpled surface placed at the end
of a short stalk, the end of the stalk is in connection with the integument of the Pycno-
gonid. Their wall is chitinous, and under this outer wall there is a much thinner inner
one ; in the stalk this inner wall is close to the outer one, but in the globular part there
is a large open space between the outer and the much smaller inner sac. In this space
pressed against the outer sac numerous eggs are found, the size of which is 0"088 mm.,
they have a very thin wall and are furnished with a yelk of large rounded elements,
coloured yellow by picrocarmine. A small nucleus as a red coloured spot, however, is
always present.

Whether these are really eggs is the first question to be answered, and I think there
can be no doubt in respect to this. Moreover, to judge from their structui'e and that
of the capsules, they are eggs that are laid after having been fecundated. There is
only one consideration, I believe, that may be set against this suggestion, and this is,
that aU these eggs are in the same state of development ; not only those of the same
capsule, but of aU the capsules I investigated. It must be borne in mind, however, that
these were brought up by the same haul of the trawl, and probably lived in the neigh-
bourhood of one another ; consequently I think this objection is of no importance.

The second question is whether they are the eggs of that Pycnogonid on the legs of
which they are found, or of another specimen of the same species, or of any other animal.
Of course it is possible that the eggs are Colossendeis eggs ; however, I do not think
this very probable. In the first place, because males and females both are studded with
these capsules, and in the second place, because these capsules are totally diiierent froni
the egg-masses commonly found on the ovigerous legs of the Pycnogonids. In favour of

144 THE VOYAGE OF H.M.S. CHALLENGER.

this opinion may be advanced that — at any rate as far as I know — hitherto no specimen
of one of the known species of Colossendeis has been caught with egg-masses on its
ovicerous legs. Considering that they are not the eggs of the Colossendeis itself, it
becomes almost impossible to form an opinion as to the animal they belong to. Among
the gastropodous molluscs numerous forms are known, which construct egg-capsules, and
attach them to foreign bodies. Perhaps the present capsules belong to an animal of that
group. That the long legs of our animals may easily be mistaken by other animals for
dead bodies is shown, I believe, by the fact that numerous other animals, which cannot be
considered as parasites, and which, as a rule, are found on stones, shells of molluscs,
carapaces of crabs, &c., fix themselves on these legs. So a small sponge and a poly-
zoon are on Nymphon hrachyrhynchus, a stalk-like process most probably of a tubularian
polyp is found on the leg of a Colossendeis ; a species of Scal2')ellum is extremely numerous
on the legs of Nymphon rohustum, Bell. Of the numerous specimens of this species col-
lected in Barents Sea, which I have investigated, there is not a single one with these
ectoparasites. But on the other hand, they are very common on the hundreds of speci-
mens of this species which were obtained by the " Knight-Errant." Professor G. 0. Sars
enumerates in his two latest papers on the Crustaceans of the Norwegian Expeditions
numerous species of Scalpellum, found at higher northern latitudes, but he does not
mention that they are found on the legs of the most common Pycnogonid of the North
Atlantic and North Polar Sea. Moreover, a preliminary comparison of this species of
Scal2xlluni shows differences with those described. I therefore believe it to be a new
one, and wish to name it Scalpellum nym2Jhocola.

SUMMARY OF THE REPORT.

1. Of the forty-one species of Pycnogonida dredged during the voyage of H.M.S.
Challenger and the cruise of the " Knight-Errant " thirty-three are new to science.

2. Of the nine genera represented in those collections three are new.

3. Those genera which range most widely geographically are also those w^hich range
most widely in depth.

4. There are deep-sea species, but true deep-sea genera do not seem to exist.

5. The Pycnogonida form a distinct and very natural group (class) of arthropodous
animals. Their common progenitor (their typical form) must be considered as a h}^o-
thetical Pycnogonid with three-jointed mandibles, multi-jointed palpi, and ovigerous legs
with numerous rows of denticulate spines on the last joints.

6. This class of the Arthropoda may be thus characterised : — Arthropoda breathing Ijy
the general surface of the body, which body consists of a cephalothoracic, three thoracic
segments, and a rudimentary abdominal segment. The cephalic part of the cephalothoracic
segment bears anteriorly a proboscis, consisting of three coalesced parts, one prse-oral
(labrum ?), two post-oral ones (mandibles ?), and three paii* of cephalic appendages, the
first two of which in the adult state sometimes have become rudimentary, the third pair
being always present at least in one of the two sexes. The first pair of these appendages
represents the antennae, the two others are post-oral. The thoracic part of the cephalo-
thoracic segment and the three thoracic segments are each furnished with a pair of long
eight-jointed legs, into which the alimentary canal sends ofi" long coeca.

7. The function of the integumentary cavities is primarily respiratory.

8. The typical form of the nervous system shows a supraoesophageal and five
thoracic ganglia. The supraoesophageal ganglion gives ofi" the nerves for the mandibles
(antennse), the integumentary nerves, and a strong nerve for the proboscis. Besides these
it probably gives ofi" nerves for the intestine (sympathic nerves). The first thoracic
ganglion consists of two coalesced ganglia, and gives ofi" four pairs of nerves, two pairs
innervating the proboscis, then the pair of palpar nerves, and finally those for the ovi-
gerous legs. The following four ganglia give ofi" the nerves for the four pairs of legs ; the
last ganglion gives sometimes two sometimes one pair of nerves for the abdomen.

9. In addition to the nerves mentioned above the proboscis is innervated by three
strong bundles of nerves and ganglia united by a stronger and some feebler secondary
oesophageal nerve rings.

(ZOOL. CHALL. EXP. — PART X. — 1881.) K 19

14G THE VOYAGE OF H.M.S. CHALLENGER.

10. In some genera the inner surface of the integument is covered by a net-work of
nerves and ganglia in connection with, and most probably issuing from, the integu-
mentary nerves given off by the supracesophageal ganglion.

IL In the most primitive condition the eye of the Pycnogonid consists of a rounded
transparent part of the integument, the inner surface of which is furnished with some
small ganglia and nerve-fibres issuing from the integumentary nerve bundle. The highly
developed eye of the shallow-water species shows ganglionic cells, distinct retinal rods,
and a lens consisting of a thickened part of the chitinous skin of the animal.

12. Those eyes which have lost their pigment and their retinal rods are rudimentary.
They cannot be considered as forming the transition between the highly-developed eye
and its most primitive condition.

13. That part of the oesophagus which runs through the proboscis has the function of
a masticating apparatus. Where the oesophagus enters the intestinal tract (the stomach)
small glands (pancreatic, most probably) are present.

14. The original condition of the genital glands is in the form of a U-shaped mass,
placed above the intestine and giving off branches which penetrate the legs. Whereas for
the male glands the original form prevails in most (all ?) genera, for the female glands it
seems to be a rule that only the lateral parts entering the legs are developed. The genital
pores of the females are larger than those of the males ; they are found ventrally towards
the extremity of the second joint of the leg. Whereas for the females it is the rule that
these pores are present on aU the legs ; it often happens in the males that they are only
present on the two or three hindmost pair of legs.

15. There are always distinct vasa efferentia, but there are not always true oviducts.

16. In Nymphon hrevicaudatmn, Miers, females also bear the eggs on the ovigerous legs.

17. The larva creeping out of the egg is already furnished with an azygous outgrowth
of the region surrounding the mouth (the proboscis). As a rule in that stage only three
pairs of ajjpendages (the later cephalic ones) are present.

18. These larvae are often furnished on their mandibles with an apparatus producing a
single or numerous threads, wherewith the young is attached to the ovigerous leg of its
parent.

19. About the relation in which the Pycnogonida stand to either the Crustacea or
the Arachnida we know as much or as little as we do about the relation in which these
two classes Arthropoda stand to each other.

Note. — While I was engaged in preparing the index of this report, and after the
rest of it had been printed off, Mr Edmund B. Wilson of Baltimore kindly sent me two
papers which he had recently published. In one (the Pycnogonida of New England and
Adjacent Waters, Eeport of the United States Commissioner of Fish and Fisheries, part
vi. for 1878, pp. 463-506, pis. i.-vii.) the author gives an account of the present know-

REPORT ON THE PYCNOGONIDA.

147

ledge of the species of Pycuogouida known to occur on the coasts of New England and
Nova Scotia. With two exceptions {Achelia scabra, Wilson, and Nymphon macrum,
Wilson) the species here described are the same as those of a former paper by Mr Wilson,
published in the Trans. Connect. Acad. Sci., vol. v. pp. 1-26, 1880. The new Achelia
is quite unknown to me, but Nymphoa macrum, Wils., is undoubtedly the species
which. I have described in my report (p. 45) as Nyinp>}ion brevicollum. The Challenger
specimens were taken south of Halifax (83 fathoms), those described by Mr Wilson
in the Gulf of Maine (85 to 115 fathoms).

The other paper (Reports on the Results of Dredging, under the Supervision of
Alexander Agassiz, along the East Coast of the United States, during the summer of 1880,
by the United States' Coast Survey Steamer " Blake," Commander J. R. Bartlett, U.S.N.,
commanding, xiii. Report on the Pycnogonida, by Edmund B. Wilson ; Bulletin of
the Museum of Comparative Zoology at Harvard College, vol, viii.. No. 12, Cambridge,
Mass., March 1881, pp. 239-256, pis. i.-v.) contains descriptions of. ten species of Pycno-
gonids, five of which are new. These belong to three genera, two of which are con-
sidered by the author as new. ' The new species are in the first place two species of
Colossendeis, Jarzynsky, Colossendeis colossea, and Colussendeis macerrima. Then a
new genus Scaeorhyiichiis, with the species Scaeorhynchus armatus, is proposed ; finally,
the new genus Fallenopsis, with the species Pcdlenopsis forjicifer and Pallenoims
longirostris, is described. The descriptions are illustrated by very good figures. On
comparing these figures and descriptions with those of my report, there can be little
doubt that Colossendeis colossea and C. imtcerrimo/ are very nearly related to, if not
identical with, my Colossendeis gigas and C. leptorhynchus. As to the genus Scaeo-
rhynchus, I do not think there are suSicient grounds for separating it from Ascorhynchus,
G. 0. Sars. Neither the presence of dactyli on the first pair of legs, nor the structure
of the rudimentary mandibles (antennae) makes it proper to separate these genera :
Scaeorhynchus (like Gnamptorhynchus, Bohm) is only a synonym of Ascorhynchus.
The species armatus, Wilson, seems to be different from those hitherto described, and
also from those of the present report.

The new genufi Palleno'psis is intended to embrace those species which come near to
Phoxichilidium, but which are characterised by ten-jointed accessory legs present in both
sexes, and by three-jointed mandibles. Three (perhaps four) species described in my
report show these characters also, and (pp. 82 and 88) I have been long in doubt whether
I should not propose a new genus for these species. I did not take the step because I do
not wish to augment the number of genera more than necessary until our knowledge
of generical characters is more perfect. Mr Wilson is not so slow in proposing new
genera ; in the present instance, I believe, however, that his proposal has a fair chance of
being accepted. The two species described by Mr Wilson are, I believe, difi"erent from
those described in my report.

WOODS
HOL-E,
MASS.

148 . THE VOYAGE OF H.M.S. CHALLENGER.

I reoret very much that in my report species will be found mentioned, described, and
figured as new, which at the date of its publication will have been already described.
As I was aware of the large collections of deep-sea animals collected by Professor
Alexander Agassiz, and felt sure that my report, with its numerous plates, would take
a considerable time in passing through the press, I took the liberty of writing to
Professor Agassiz, to ask him to whom the working-out of the Pycnogonids of his latest
cruises had been entrusted. He kindly comphed with my request, and informed me that
the Pycnogonids along with the Crustacea had been sent to Professor Alphonse Milne-
Edwards in Paris. I then addressed Professor Milne-Edwards, sending him at the same
time proof-copies of the plates of my report on which the new species were figured, and
as he favoured me with an answer, in which he promised to make use of the names
proposed by me, I had every reason to believe that zoological literature, at least in the
case of the deep-sea Pycnogonida, would not be encumbered by synonyms. Where I
have not been successful in this respect I hope nobody will lay the blame upon me.

Leiden, I9th May 1881.

EXPLANATION OF PLATES.

O'

PLATE I.

Nymjithon hamatum, n. sp. (figs. 1-9).
Fig. 1. Male, dorsal view; magnified 3 diameters.

2. Male, ventral view ; magnified 7 diameters.

3. The claws of the mandibles; magnified 41 diameters.

4. The last four joints of the ovigerous legs ; magnified 34 diameters.

5. The denticulate spines of the ovigerous legs; magnified 272 diameters.

6. The second coxal joint of the leg of a female ; magnified 6 diameters.

7. The tubercles on the thigh of the male ; magnified 94 diameters.

8. The hook-like process at the end of the thigh ; magnified 41 diameters.

9. The last two joints and the claw of one of the legs ; magnified 21 diameters.

PLATE IL

Nyin2)hon longicoxa, n. sp. (figs. 1-5).
Male, dorsal view ; magnified 7| diameters.
The last four joints of the palpus ; magnified 20 diameters.
The claws of the mandibles ; magnified 94 diameters.
The denticulate spines of the ovigerous legs ; magnified 272 diameters.
The last two joints and the claw of one of the legs ; magnified 41 diameters.

NympJion co7)ipactum, n. sp. (figs. 6-8).
6. Female, ventral view ; magnified 6^ diameters.
„ 7. Part of the body of a female, dorsal view ; magnified 8 diameters.
„ 8. The denticulate spines of the ovigerous legs ; magnified 272 diameters.

Nymjyhon procerum, n. sp. (figs. 9-12).
Fig. 9.. Female, dorsal view ; magnified 6f diameters.
,, 10. The claws of the mandibles ; magnified 94 diameters.
,, 11. The claw of the ovigerous leg; magnified 94 diameters.
„ 12. The denticulate spines of the ovigerous legs ; magnified 272 diameters.

Fig.

1.

j;

2.

>y

3.

3?

4.

JJ

5.

Fig.

6.

150 THE VOYAGE OF H.M.S. CHALLENGER.

. PLATE III.

Nymiithon longicolbnn, n. sp. (figs. 1-3).

Fig. 1. Male, dorsal view ; magnified 6f diameters.
,, 2. The same, seen ventrally ; -magnified 20 diameters.
3. The claws of the mandibles ; magnified 47 diameters.

Nymphon mendionale, n. sp. (figs. 4-8).

Fig. 4. Male, dorsal view ; magnified 20 diameters.
,, 5. The claws of the mandibles ; magnified 94 diameters.

, , 6. Claw and last part of the tenth j oiut of the ovigerous leg ; magnified 272 diameters.
,, 7. The last two joints of the leg; magnified 41 diameters.

„ 8. The claw with one of the secondary claws of one of the legs; magnified 136
diameters.

Nipnphon grossipes, Fabr. (sp.), (figs. 9-12).
Called Nymphon armatmn, n. sp., at the foot of the plate.

Fig. 9. Male, ventral view ; magnified 6f diameters.
., 10. The claws of the mandibles; magnified 41 diameters.
,, 11. The denticulate spines of the ovigerous legs; magnified 575 diameters.
, 12. The last joint of the leg of a female ; magnified 41 diameters.

Nymphon brevicolliivi , n. sp. (figs. 13-15).

Fig. 13. Female, ventral view; niagnified 6f diameters.
.., 14. Claw and last part of the tenth joint of the ovigerous leg; magnified 272

diameters.
„ 15. Claw with one of the secondary claws of the leg ; magnified 94 diameters.

PLATE IV.

Nymp)hon grossqyes, Fabr. (sp.) (fig. 1),
Colled Nymp>hon armatmn, u. .sp., at the foot of the plate.

Fig. 1. Oculiferous tubercle ; magnified 41 diameters.

Nymphon hrachyrhynchus, n. sp. (figs. 2-7).

Fig. 2. Male, dorsal view; magnified 41 diameters.
,, 3. Female, ventral view ; magnified 6f diameters.

REPORT ON THE PYCNOGONIDA. • 151

Fig. 4. The claws of the mandibles ; magnified 94 diameters.

„ 5. Palpus; magnified 41 diameters.

,, 6. Claw of the ovigerous leg ; magnified 272 diameters.

„ 7. Claw of one of the legs ; magnified 94 diameters.

Nymphon fuscum, n. sp. (figs. 8-11).

Fig. 8. Male, ventral view ; magnified 6f diameters.

,, 9. The claws of the mandibles ; magnified 94 diameters.

,, 10. Palpus; magnified 41 diameters.

„ 11. Claw of the ovigerous leg ; magnified 180 diameters.

Nymphon hrevicauclatum, Miers (figs. 12-13).
Called Nymphon hispidum, n. sp., at the foot of the plate.
Fig. 12. Male, dorsal view; magnified 12 diameters.
„ 13. Male, ventral view; magnified 6 diameters.

PLATE V.

Nym2')hon breviccmdatum, Miers (figs. 1-5).
Called Nymphon hispidum, n. sp., at the foot of the plate.

Fig.. 1. Palpus; magnified 41 diameters.

„ 2. Claws of the mandibles ; magnified 41 diameters.

„ 3. Last five joints of the ovigerous leg ; magnified 41 diameters.

„ 4. Denticulate spine of the ovigerous leg ; magnified 272 diameters

,, 5. Last two joints of the leg ; magnified 34 diameters.

Nymphon pierhicidum, n. sp. (figs. 6-10).

Fig. 6. The front part of the body, seen ventrally ; magnified 41 diameters.
,, 7. The whole animal, dorsal view ; magnified 6| diameters.
„ 8. The last four joints of the ovigerous legs ; magnified 94 diameters.
,, 9. Two of the denticulate- spines of the ovigerous leg; magnified 272 diameters.

„ 10. The last two joints of the leg ; magnified 36 diameters.

Ascorhynchus orthorhynchus, n. sp. (figs. 11-13).

Fig. 11. Dorsal view ; magnified 3^ diameters.
„ 12. Ventral view; magnified 2 diameters.
„ 13. Palpus; magnified 21 diameters.

152 THE VOYAGE OF H.M.S. CHALLENGER.

PLATE VI.

Ascorhynchus orthorhynchus, n. sp. (figs. 1-4).

Fifj. 1. Eudimentaiy mandible ; magnified 94 diameters.
,, 2. The last four joints of the ovigerous leg; magnified 21 diameters.
,, 3. The denticulate spines of one of the joints of the ovigerous leg ; magnified 272

diameters.
,, 4. The last two joints of the leg; magnified 21 diameters.

Ascorhynchus glaber, n. sp. (figs. 5-9).

Fig. 5. Dorsal view ; magnified 5^ diameters.

„ 6. Mandibles; magnified 21 diameters.

,, 7. The mandible of a young specimen; magnified 94 diameters.

„ 8. The last four joints of the ovigerous leg ; magnified 21 diameters.

,, 9. The last joint of the leg; magnified 21 diameters.

Ascorhynchus minutus, n. sp. (figs. 10-16).

Fig. 10. Ventral view ; magnified 7 J diameters.

„ 11. Side view ; magnified 7^ diameters.

„ 12. The last three joints of the ovigerous leg ; magnified 70 diameters.

„ 13. The eighth joint of the ovigerous leg ; magnified 182 diameters.

„ 14. The last two joints of the leg; magnified 70 diameters.

„ 15. The last joint of the first leg; magnified 94 diameters.

„ 16. Hairs of the palpus ; magnified 272 diameters.

PLATE VIL

Oorhynchus aucklandice, n. sp. (figs. 1-7).

Fig. 1 . Ventral view ; magnified 1 .5 diameters.

2. Dorsal view ; magnified 7\ diameters.

3. The front part seen dorsally ; magnified 34 diameters.

4. Palpus ; magnified 94 diameters.

5. The last four joints of the ovigerous leg ;• magnified 130 diameters.

6. One of the legs ; magnified 34 diameters.

7. The last two joints of the leg ; magnified 70 diameters.

REPOET ON THE PYCjSTOGONIDA. 153

Discoarachne l>revlpes, n. sp. (figs. 8-12),

Fig. 8. Dorsal view ; magnified 8 diameters.
,, 9. Ventral view ; magnified 8 diameters,
„ 10. Palpus; magnified 94 diameters.

,, 11. The last four joints of the ovigerous leg ; magnified 94 diameter.-'.
„ 12. Tlie last two joints of the leg ; magnified 94 diameters.

PLATE VIII.

Colossendeis gigas, n. sp, (figs, 1-2).

Fig. 1, Ventral view ; natural size.
„ 2. Dorsal view of the body ; natural size.

Colossendeis leptorhynchus, n. sp. (figs. 3-7).
Fig. 3. Ventral view ; natural size.
„ 4. Dorsal view of the body ; natural size.
„ 5. The last four joints of the palpus ; magnified 30 diameters.
„ 6. The last four joints of the ovigerous legs ; magnified 21 diameters.
„ 7. The claw of one of the legs ; magnified 48 diameters.

PLATE IX.

Colossendeis megalonijx, n. sp, (figs, 1-3).
Fig. 1. Lateral view; magnified 2 diameters,
„ 2, The last three joints of the palpus ; magnified 39 diameters.
„ 3. The arrangement of the denticulate spines on the ninth joint of the ovigerous
leg ; magnified 94 diameters.

Colossendeis rohusta, u. sp. (figs. 4, 5).

Fig. 4. Dorsal view ; magnified 2 diameters.
„ 5, The arrangement of the denticulate spines on the ninth joint of the ovigerous
leg; magnified 41 diameters.

Colossendeis gracilis, n, sp, (figs, 6-8).

Fig. 6. Ventral view ; magnified 5 diameters,
„ 7. The last four joints of the palpus; magnified 41 diameters.
„ 8. The arrangement of the denticulate spines on the ninth joint of the ovigerous
leg ; magnified 235 diameters.

(ZOOL. CHALL. EXP. PART X. — 1881.) K 20

154 THE VOYAGE OF H.M.S. CHALLENGER.

PLATE X.

Colossendeis gig(ii<, n. sp. (figs. 1-5).

Fio-. 1. The arrangement of the denticulatr' spines at the ninth joint of the ovigerous
leg; magnified 41 diameters.

„ 2. One of the denticulate spines of the ninili joint of the ovigerous leg of an old
specimen; magnified 136 diameters.

„ 3. The same of an outside row of a younger specimen ; magnified 136 diameters.

,, 4. The same of an inside row of a younger specimen ; magnified 136 diameters.

,, 5. Two rudimentary spines of a row quite to the inside of an old specimen ; magni-
fied 136 diameters.

Colossendeis gracilis, n. sp. (figs. 6-7).

Fig. 6. Specimen with mandibles, dorsal view ; magnified 6i diameters.
„ 7. The arrangement of the denticulate^ spines on the ninth joint of the ovigerous
leg ; magnified 94 diameters.

Colossendeis hrevipes, n. sp. (figs. 8-9).

Fig. 8. The last five joints of the palpus ; magnified 20 diameters.
,, 9. The arrangement of the denticulate spines on the ninth joint of the ovigerous
leg ; magnified 94 diameters.

Colossendeis minuta, n. sp. (figs. 12-14).

Fig. 12. Dorsal view; magnified 6 diameters.
,, 13. The last five joints of the palpus; magnified 41 diameters.

„ 14. The arrangement of the denticulate spines on the ninth joint of the o%'igerous
leg ; magnified 272 diameters.

PLATE XL

Pallene australiensis, n. sp. (figs. 1-7).

Fig. 1. Ventral view ; magnified 7 diameters.

,, 2. Dorsal view; magnified 17 diameters.

,, 3. Claws of the mandibles ; magnified 94 diameters.

„ 4. Last five joints of the ovigerous leg of the male ; magnified 34 diameters.

„ 5. Ninth joint of the ovigerous leg of the male ; magnified 270 diameters.

,, 6. Last two joints of the leg ; magnified 65 diameters.

„ 7. Spine on the sixth jomt of the leg ; magnified 270 diameters.

REPORT ON THE PYCNOGONIDA. 155

Pallene Icevis, u. sp. (figs. 8-12).

Fig. 8. Female specimen, dorsal view ; magnified 6 tliameters.
„ 9. Female specimen, ventral view ; magnified 17 diameters.
„ 10. Last four joints of the ovigerous leg; magnified 65 diameters.
,, 11. Last joint of the ovigerous leg ; magnified 272 diameters.
,, 12. Last two joints of the leg ; magnified 41 diameters.

PLATE Xn.

Pallene languida, n. sp. (figs. 1-5).

Fio. 1. Ventral view : magrnified 41 diameters.

,, 2. Dorsal view; magnified 41 diameters.

,, 3. Last joint of the mandible ; magnified 94 diameters.

„ 4. Last five joints of the ovigerous leg ; magnified 94 diameters.

,, 5. Denticulate spines of the ovigerous leg ; magnified 575 diameters.

Phoxichilidium patagonicmn, n. sp. (figs. 6-9).

Fig. 6. Dorsal view, natural size.

„ 7. Ventral view ; magnified 6 diameters.

,, 8. Last four joints of the ovigerous leg ; magnified 36 diameters.

,, 9. Last two joints of the leg ; magnified 6 diameters,

Phoxichilidium ixttagonicum, var. elcgans, Hoek (fig. 10).
Fig. 1 0. Ventral view ; magnified 8 diameters.

PLATE XIIL

Phoxichilidium oscitans, n. sp, (figs. 1-5).

Fig. 1 . Dorsal view ; magnified 4 diameters.

,, 2, Front part of the body, seen ventrally ; magnified 8 diameters.

,, 3. The mouth seen from the front ; magnified 7 diameters.

,, 4. Last four joints of the ovigerous leg; magnified 41 diameters.

,, 5. Last two joints of the leg ; magnified 8 diameters,

Phoxichilidium mollissim'um, n. sp. (figs. 6-9).

Fig. 6. Lateral view ; magnified 4 diameters.
„ 7. Mouth, front view ; magnified 9 diameters.

156 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 8. Last four joints of the ovigerous leg ; magnified 28 diameters.
,, 9. Part of tlie sixth joint of the leg ; magnified 8 diameters.

Phoxichilidium pilosum, n. sp. (figs. 10-13).

Fig. 10. Dorsal view; magnified 5 diameters.

„ 11. Front part of the body, s^entral view; magnified 9 diameters.

„ 1-2. Last four joints of the ovigerous leg; magnified 41 diameters.

„ 13. Last two joints of the leg; magnified 9 diameters.

PLATE XIY.

Phoxichilidium flinninense , Kroyer (figs. 1-4).

Fig. 1. Ventral view; magnified 8 diameters.

,, 2. Oculiferous tubercle, dorsal view ; magnified 28 diameters.

,, 3. Last five joints of the ovigerous leg ; magnified 56 diameters.

„ 4. Last two joints of the leg ; magnified 28 diameters.

Phoxichilidium insigne, n. sp. (figs. 5-7).

Fig. 5. Dorsal view ; magnified 8g diameters.

6. Front part of the body, seen ventrally ; magnified 28 diameters.
,, 7. Last two joints of the leg ; magnified 56 diameters.

Hannonia ti/pica, n. gen., n. sp. (figs. 8-11).
Fig. 8. Dorsal view ; magnified 17 diameters.
,, 9. Ventral view ; magnified 5h diameters.

,, 1 0. La.st four joints of the ovigerous leg ; magnified 70 diameters.
,, 11. Last two joints of the leg; magnified 30 diameters.

PLATE XV.

Nymphon macronyx, G. 0. Sars. (figs. 1-7).

Fig. 1. Ventral view; magnified 7 diameters.

2. Oculiferous tubercle ; magnified 64 diameters.

3. Mandil^lc ; magnified 41 diameters.

4. Palpus; magnified 41 diameters.

5. Denticulate spines of the ovigerous legs ; magnified 272 diameters.
G, Claw of the ovigerous leg ; magnified 272 diameters.

7. Last two joints of the leg ; magnified 41 diameters.

EEPORT ON THE PYCNOGONIDA. 157

Nymphon longicoxa, Hoek (figs. 8, 9).

Fig. 8. Spines at the sixth joint of the ovigerous leg of a male ; magnified 272 dia-
meters.
„ 9. Genital opening of the male ; magnified 136 diameters.

Nymplion compactwn, Hoek (fig. 10).
Fig. 10. Last two joints of the leg; magnified 7 diameters.

Nymphon longicoUum, Hoek (fig. 11).
Fig. 11. Auxiliary claws ; magnified 272 diameters.

Nymphon hrevicollum, Hoek (figs. 12, 13).

Fig. 12. Articulation (?) in the fifth joint of the ovigerous leg of the male; magnified
94 diameters.
„ 13. The ovigerous leg of the male ; magnified 7 diameters.

Ascorhynchus orthorhynchus, Hoek (figs. 14, 15).

Fig. 14. Mouth, front view; magnified 5 diameters.
„ 15. Genital pore of the female ; magnified 64 diameters.

Ascorhynchus glaher, Hoek (fig. 16).
Fig. 16. Articulation of the proboscis; magnified 6 diameters.

PLATE XVL

Structure of the integument of Nymp)hon robustum, Bell (figs. 1-3).

Fig. 1. Transverse section of the integument ; magnified 272 diameters. «, spine ; b,
respiratory cavity ; c, setse ; d, nerve ; e, blood-corpuscles ; /, epithelium.
,, 2. Setas ; magnified 575 diameters.
„ 3. Set£e ; magnified 575 diameters.

Structure of the integument oi Nymp)honhamatum, Hoek (figs. 4-6).

Fig. 4. Surface of the fourth joint of the leg of a male ; magnified 94 diameters, g, j^ores.
„ 5. Structure of the gland ; magnified 272 diameters.

,, 6. Transverse section of the thigh of a male ; magnified 94 diameters, g, pore ;
k, l^lood ; i, intestinal ccecum ; h, gland.

Structure of the integument of Nymphon brevicaudatum, Miers (fig. 7).

Fig. 7. Transverse section of the fourth joint of the leg of a female ; magnified 56
diameters. {, as in fig. 6 ; I, mature egg ; m, immature eggs ; x, mud.

I5g THE VOYAGE OF H.M.S, CHALLENGEK.

Structure of the integument oi Ascorhynclius glaher, Hoek (figs. 8-10).

Fig. 8. Transverse section of a part of the integument ; magnified 272 diameters, h, c,

e, as in fig. 1.

„ 9. Transverse section of the thigh of a male ; magnified 56 diameters, n, testis ;

g, h, i, k, as in fig 6.
„ 10. Cells from the glandular mass of the male ; magnified 272 diameters.

Genital organs, &c., oi AscorJiynchus orthorhynchus, Hoek (fig. 11).

Fig. 11. Transverse section of the thigh of a female ; magnified 56 diameters, k, m, h, i,
as in figs. 6 and 7.

Structure of the integument of Colossendeis leptorhynchus, Hoek (figs. 12, 13).

Fig. 12. Transverse section of a part of the integument ; magnified 170 diameters, h, e,
as in fig. 1.
,, 13. Spine; magnified 170 diameters.

Structure of the integument of Colossejideis megalonyx, Hoek (fig. 14).

Fig. 14. Transverse section through the thigh of a male; magnified 41 diameters, h, i,
as in fig. 6.

Structure of the integument, &c., of Colossendeis lejJtorhynchns, Hoek (figs. 15, 16).

Fig. 15. Transverse section through the thigh of a male; magnified 272 diameters, o,
vesicle ; p, wounded canal.
,, 16. Transverse section of the thigh of a female; magnified 56 diameters, m, i, as
in fig. 7.

Structure of the integument of Fhoxichilidmm 2xitagonicum, Hoek (fig. 17).

Fig. 17. Transverse section of the integument of a female ; magnified 170 diameters, b, c,

f, as in fig. I.

Structure of the integument, &c., oi Phoxidiilidmin insigne, Hoek (fig. 18).

Fig. 18. Transverse section of the thigh of a male ; magnified 94 diameters, h, i, k, as
in fig. 6.

PLATE XVn.

Fig. 1. Colossendeis proboscidea, Sab. (sp.); dorsal half of the body; magnified 6
diameters, a, intestine ; a\ «^ two short casca not reaching beyond the
cephalothorax ; b, muscles moving the proboscis ; c, heart ; d, anus.

REPORT ON THE PYCNOGONIDA. 159

Fig. 2. Colossendeis lirohoscidea, Sab. (sp.) ; ventral liaK of the body with the nervous
system ; magnified 6 diameters, a, parts of the intestine ; p, palpus ; I. II.-
V., first to fifth thoracic ganglia ; n.p. and n.pr., two branches of the palpar
nerve ; n.o.l., nerve for the ovigerous leg ; ??^-n*, four nerves for the legs ;
n.a., nerves for the abdomen.

„ 3. Nymphon robustwn. Bell ; ventral half with the nervous system ; magnified 6
diameters, a, j^arts of the intestine, <;oeca, &c. ; m.ii., muscles running from
the one segment to the other ; n.p., palpar nerve ; n.pr., proboscideal nerve ;
n.o.l., 11^-11*, n.a., as in fig. 2.

,, 4. Nympihon rohustum. Bell ; supraoesophageal ganglion with its nerves ; magnified
6 diameters, a, intestine ; in, mandibles ; g.s.o., supraoesophageal ganglion ;
c, oesophageal commissures; n.m., nerve for the mandibles; u.p.n., ma'paiv
proboscideal nerve; p.p.n., small proboscideal nerves; ^r.jj., proboscideal
ganglion.

„ 5. Nymphon rohustum, Bell ; dorsal half of the body showing the intestine ; mag-
nified 4 diameters, a, intestine ; e, oesophagus.

„ 6. Nymphon rohustum. Bell ; part of the intestine ; magnified 47 diameters, a,
intestine ; e, oesophagus ; gl, intestine glands.

PLATE XVIII.

Fig. 1. Integumentary cavities of Colossendeis leptorhynchus, Hoek ; $ sj)ecimen ; first
tibial joint ; magnified 287 diameters, i, part of the wall of the intestinal
coecum ; c, septa of connective tissue ; h, blood-corpuscles ; d, and d' , glandu-
lar cells.

„ 2. Transverse section of the fourth joint of the leg of Colossendeis prohoscidea, Sab.
(sp.) ; $ specimen ; magnified 47 diameters, i, intestinal coecum ; g, glands ;
t, testis ; c, filires of connective tissue.

„ 3. Part of the integument of Colossendeis prohoscidea, Sab. (sp.) ; fourth joint of
the leg ; $ specimen ; magnified 272 diameters, c, integumentary cavity ; g,
gland ; d, duct of the gland.

„ 4. CEsophageal ring of Colossendeis megalonyx, Hoek ; magnified 40 diameters,
s. supraoesophageal ganglion ; c, commissures ; t, first thoracic ganglion ;
])r. az}-gous proboscideal nerve ; m, mandibular nerve ; o, optic nerves (?) ; t',
first nerve arising from the first thoracic ganglion ; t", second nerve (one of
the three main proboscideal nerves), dividing into two branches after pene-
trating the proboscis; jxt., palpar nerve (dividing in two branches close to
the ganglion) ; o, nerve for the ovigerous leg ; c , commissures between the
first and second thoracic gangha.

160 THE VOYAGE OF H.M.S. CHALLENGER.

Fig. 5, Innervation of the rudimentary eyes of Nymiihon rohtistum, Bell ; magnified 94
diameters, n, optic nerves forming the ganglion g ; t, oculiferous tubercle ;

0, rudimentary eyes.

„ 6. Innervation of the proboscis of Nijmphon rohustum, Bell; magnified 10 dia-
meters. The proboscis has been figured as transparent ; the mandible and
the palp of the left side have been cut away, t, oculiferous tubercle ; s, supra-
cesophagal ganglion ; c, cesophagal commissures ; ti, azygous proboscideal
nerve ; ^, secondary proboscideal nerves arising from the supraoesophageal
ganglion ; mn, mandibular nerves ; 'p, proboscideal nerves arising from the
first thoracic ganglion ; g, ganglionic bundles ; x, small ganglia in the front
of the proboscis ; y, large proboscideal ganglia ; a, first proboscideal nerve
ring ; a'-ct'"^ second to fifth proboscideal ring.

„ 7. Transverse section of cephalothoracic segment of Colossendeis leptorhynchtis,
Hoek (female specimen) ; magnified 10 diameters, s, supraoesophageal gan-
glion ; t, first thoracic ganglion ; os, oesophagus ; c, oesophageal commissures ;
i, rudimentary coeca of the intestine ; m, and m'. muscle-bundles ; m, passing
through the oesophageal commissures.

„ 8. Part of the ganglionic bundle in the proboscis of Nymphon rohustum, Bell*;

magnified 94 diameters, u, g, a, a', a", x, and y, as in fig. 6.
„ 9. Transverse section of the proboscis of Nymphon rohustum, Bell ; magnified 23
diameters. I., II., and III. the three chitinous plates limiting the oesophageal
cavity ; t, transverse muscles ; I, longitudinal muscle-bundles ; a, proboscideal
ring ; g, ganglion of the ganglionic bundle ; ^3, the three main proboscideal
nerves on transverse section.

,, 10. One of the ganglia on the inner surface of the integument of Colossendeis i^ro-
boscidea, 8ah. (sj).) ; magnified 272 diameters, c, integumentary cavities;
b, blood-corpuscles.

„ 11. Six sections through the supraoesophageal and first thoracic ganglia of Nym-
phon stromii, Kroyer ; magnified 56 diameters, s, supraoesophageal ganglion ;
ce, oesophagus ; t, first thoracic ganglion ; i, intestinal coecum for the
mandibles ; c, fibres of connective tissue ; o, optic lobes ; o', part of the
optic nerves ; m, mandibular lobes ; x, azygous lobe of unknown function ;
CO, oesophageal commissures ; p, origin of the two main proboscideal nerves ;

1, origin of the nerves for the ovigerous legs ; co', commissures between the
first and second thoracic ganglia.

,, 12. Longitudinal section through the first thoracic ganglia of Nymjyhon brachy-
rhynclms, Hoek ; magnified 170 diameters, pr, proboscideal nerves ; pa, part
of the neurilemma of the palpar nerve ; e, part of the neurilemma of the oviger-
ous nerve ; c, commissure between this and the second thoracic ganglion.

REPORT ON THE PYCNOGONIDA. 161

PLATE XIX.

Fig. 1. Bgg-m.a.ss, oi Nymphon breviGoUumjUoek; magnified 16 diameters.

2. Transverse section of egg-mass of Nymphon brevicollum, Hoek; magnified 41
diameters, o, opening occupied by the ovigerous leg ; s, small pores left
between the eggs ; c, the substance soldering the eggs together ; m, mud.

3. Transverse section of the egg of Nymphon brevicoUmn, Hoek ; magnified 272
diameters.

4. Structure of the protoplasm of one of the segments of the same egg ; magnified
575 diameters.

5. Cells of the blastoderm and segments of the nutritive yolk of Nymp)lion bi-evi-
Gcmdatmn, Miers ; magnified 272 diameters.

6. Nuclei of the cells of the blastoderm of the egg of Nymphon brevicavdatum,
Miers ; magnified 575 diameters.

7. Transverse section through the egg (jf Nymphon brevicaiidatum, Miers ; magni-
fied 94 diameters.

8. Embryo of Nymphon brachyrhynchus, Hoek, showing the three pairs of append-
ages and the proboscis ; magnified 94 diameters.

9. Front part of the embryo of Nymphon brevicaudatum, Miers, seen ventrally ;
magnified 135 diameters.

10. The embryo of Nymphon brevicaudatum, Miers, ventral view; magnified 94
diameters.

1 1 . Transverse section through the egg of Nymp)hon brevicaudatum, Miers ;
magnified 94 diameters, a, mandible ; b, first pair of legs ; c, d, second and
third pair of cephalic appendages.

12. Larva of Nymphon brevicollum, Hoek, dorsal view ; magnified 94 diameters.

13. Larva oi Nympjhon brevicollum, Hoek, ventral view; magnified 94 diameters.

PLATE XX.

Fio'. 1. Larva oi Nymphon brevicollum, Hoek; magnified 94 diameters.

2. Spinning apparatus in the mandible of the larva of Nymphon brevicollum, Hoek ;

magnified 94 diameters.

3. Front part of the larva of Nymphon hamatum, Hoek ; magnified 94 diameters.
„ 4. Spinning apparatus in the mandible of the larva of Nymphon hamatum, Hoek ;

magnified 272 diameters.
5. Spinning apparatus in the mandible of Nymphon longicoxa, Hoek ; magnified
272 diameters.
„ 6. Larva oi Ascorhynchus minutus, Hoek ; magnified 272 diameters.

(ZOOL. OUALU liXP.— PART X, — 1881.) K 21

162 THE VOYAGE OF H.M.S. CHALLENGER.

PLATE XXL

Fig. L Eye of Nijmphon atromii, Kroyer, transverse section ; magnified 272 diameters.
2. Eye of Nijm^jlion hrachyrhynchus, Hoelc, longitudinal section, taken laterally ;

magnified 170 diameters.
,, 3. Eye of Nymjjhon brachi/rhi/nchus, Hoek, longitudinal section, passing nearly

through the middle; magnified 170 diameters.
,, 4. Ends and ganglion cells from the eye of Nymphon hrachyrhynchus, Hock ;

magnified 575 diameters.
,, 5. Eods (isolated) from the eye of Nymphon hrachyrhynchus, Hoek ; magnified

575 diameters.
„ G. Esophagus of Nymphon hamatum, Hoek, transverse section ; magnified 272

diameters.
,, 7. Glands at the end of the oesophagus of Nymjihon hamatum, Hoek ; magnified 94

diameters, a, the glands ; s, supracesophageal ganglion ; /, first thoracic

ganglion.
,, 8. Glands at the end of the oesophagus of Nymphon. hamatum, Hoek, transverse

section ; magnified 170 diameters, a, the glands ; h, the wall of the in-
testine.
,, 9. Group of fat cells from Nymphon rohustum. Bell ; magnified 272 diameters. "
,, 10. Male genital organs of Colossendeis 2:)rohosciclea, Sab. (sp.), natural size, a,

testis ; h, intestine.
,, 11. The opening of the male genital organs in the second joint of the leg of Colos-
sendeis prohoscidea, Sab. (sp.). a, testis ; h, intestine ; c, vas eflerens.
,, 12. Transverse section of the testis of Colossendeis prohoscidea, Sab. (sp.) ;

magnified 94 diameters.
,, 13. Histological structure of the wall of the vas efferens of Colossendeis prohoscidea,

Sab. (sp.) ; magnified 575 diameters.
,, 14. Transverse section of the body of Colossendeis leptorhynchus, Hoek, about

between the second and third leg ; magnified 20 diameters, h, heart ; i'-r,

intestine ; o, ovary ; n, nervous system.
,, 15. Ovarian egg oi Nymphon brevicaudatimi, Miers ; magnified 94 diameters.
„ 16. Section of the ovary in the fourth joint of the leg of Nymphon rohustum.

Bell ; magnified 94 diameters, i, wall of the intestinal coecum ; c, cavity

completely filled with eggs, when the animal is mature.
„ 17. Egg oi Nymphon longicoxa, Hoek ; magnified 94 diameters.
„ 18. Section through the fourth joint of the leg of Phoxichilidium patagonicum,

Hoek ; magnified 41 diameters.

INDEX.

Abdomen, 16.
Acarus, 2.

Accessory claws, 16.
Achelia, 3, 9, 23, 24, 26, 27, 61.
echinata, 26.
hispida, 27.
losvis, 27.
seabra, 147.
spinosa, 24, 26.
Alainous, 5, 9, 26.

vulgaris, 26.
megacephahis, 26.
Affinities of the Pycnogonids with the other Arthro-

poda, 108.
Alimentary canal and its apijendages, 124.
Ammothea, 9, 23, 24.

achelioides, 24.
brevipes, 24.
carolinensis, 23.
lotigipes, 23.
pycnogonoides, 4, 23.
Anatomy of the Pycnogonida, 100.
Anomorhynclms smithii, 99.
Anoplodadyhw, 5, 82.

Urdus, 33.
Antliata, 2.

Apertures of the heart, number of the, 127.
Appendages, development of the, 138.

food-yolk in the, 138.
Arachnida, 2,
Aranea, 2.

Ascorhynchus, 4, 9, 10, 23, 25, 53, 147.
ahyssi, 4, 25, 55.
(/?a&er, 8, 25, 37, 53, 55.
minutus, 7, 25, 55, 58.
ovthorhynclius, 7, 25, 57.
ramipes, 25, 56, 58.

£(7eZto, 2.

Blastoderm, 137, 138.

Bell, Th., referred to, 3.

Blood-corpuscles, 128.

Blood-corpuscles in the integumentary cavities, 103.

Body of Pycnogonid, description of, 14.

(ZOOL. CHALL. EXP. PAKT X. 1881.)

Bolim, E., referred to, 4, 6, 49, 51, 82, 134.
Bohmia, 9, 24.

chelata, 24.
" Borstenapparat " of the integument, 102.
Bottom, nature of the, 12.
Brachinpoda, 8.
Briinnich, 2.
Buchholz, R, referred to, 3.

Cavanna, G., referred to, 5, 122, 128, 134.
Cavities in the integument, 101.
Cephalothoracic segment, 14.
Circulatory apjjaratiis, 127.
Claparfede, A. E. E., referred to, 4.
Claws, at the ends of the legs, 16.
Cleavage of the egg, 136.
Commensals of the legs of Pycnogonids, 144.
Coeca of the intestine, number and structure of, 8,
126.

CoLOSSENDEIDiE, 23.

Colossendeis, 3, 6, 9, 10, 23, 28, 59, 61, 70, 98.
angusta, 4, 28, 65.
horealis, 28, 98.
hrevipes, 8, 28, 29, 70, 72, 73.
colossea, 147.
gigas, 8, 28, 37, 61, 64, 65, 66, 67,

147.
gigas-leptorhynchus, 28, 65.
gracilis, 8, 28, 29, 37, 59, 69, 71, 72,

73, 74.
kroyerii, 28.

leptorhynchus, 7, 28, 37, 64, 66, 67,

74, 147.
macen'ima, 147.

media, 8, 28, 29, 70, 71, 73.

megalonyx, 7, 11, 28, 67.

minuta, 8, 11, 29, 73.

proboscidea, 7, 11, 28, 69, 98.

robusta, 7, 28, 66.
Commissures uniting the thoracic ganglia, 116.
Commissm-es, circum-a;sophageal, 109.
Copulation observed, 131.
Comiger hilgendorfl, 27.
Costa, 0. G., referred to, 5.

K 22

164

THE VOYAGE OF H.M.S. CHALLENGER.

Crustaceans, 2.

Grustac.es aranei formes, 2, 17.
Crustacea haustellata, 17.
Cyamus ceti, 2.

Davidson, referred to, 8.
Deealopoda, 6.
Depth, 8.

Diseoarachne, 9, 29, 74.

hvpi-ipes, 7, 29, 74.
Distribution, geographical, 11.
Distribution, geographical, compared with batliymet-

rical range, 10.
Dohrn, A., referred to, 5, 100, 108, 128, 129, 134,

136, 141.

Egg, 136.

Egg-packets, number, 136.

Eggjjackets, egg in the packet, 136.

Eggs of parasitic animals in the interior of Nijmphon,

143.
Eggs in capsules in connection with the integument

of Golossendeis, 143.
Eggs, way in which they are laid, 131.
Eggs, ovarian, structure and formation, 132.
Eights, referred to, 6.
Embryos, 139.

Embryology of the Pyenogouid a, 100, 134.
Endeis, 5, 9, 29, 76.

didnctyla, 29.

i/racilis, 29.
Ej'e, original. 111.
Eye, highly developed, 112.
Eye, rudimentary, 112.
Eyes, 119.
Eyes, their occurrence according to the depths they

inhabit, 120.
Eyes, minute structure of, 122.

Fabricius, J. C, referred to, 2.

Fabricius, O., referred to, 2.

Fat-cells, 127

Fdxichiius pigmcjeus, 35.

Frey, H., and Leuckart, E., referred to, 4.

Ganglia, histological structm-e, 119.

Ganglia, minute structure, 118.

Ganglia, development of, 139.

Ganglia, thoracic, 112, 116.

Ganglia, paired proboscideal, 113.

Ganglia of the inner surface of the mtegument, 116.

GangKa, abdominal, 117.

Ganglion, azygous proboscideal, 110.

Ganglion, supra-oesophageal, 109.

GangHou in the course of the ojitic nerve, 111

Ganglion, first thoracic, 112.

Ganglionic nerve bundles of the proboscis, 113.

Ganglionic nerve bundles of the proboscis, function,

115.
Gay, referred to, 6.
Genera, list of the, 9.
Genital organs, 128.
Genital pores, 129.
Germ-layers, 138.
Glands, female, 131.
Glands, male, 128.
Glands of the ovigerous legs, 105.
Glands of the palpi, 105.
Glands of the integument, 101.
Glands of the fourth joint of tlie leg of the male,

106.
Glands in the first joint of the foot-jaw of the larvae,

140.
Glands (pancreatic), 125.
Gnamptorhynchus, 6, 147.

ramipes, 25, 56.
Goodsu', Harry D. S., referred to, 3, 134.
Graber, V., referred to, 123.
Grenacher, H., referred to, 121.
Grube, E., referred to, 4, 5.

Hairs on the siu-face of the body, 104.
Hannonia, 9, 34, 92.

typica, 7, 34, 92.
Heart, 127.

Heart, development of the, 138.
Heller, C, referred to, 4, 94.
Hesse, referred to, 4.
Hodge, G., referred to, 3.

Hoek, P. P. C, referred to, 4, 93, 100, 108, 134.
Huxley, referred to, 14, 102.
Hydrachna, 1, 2.

Iiisecta aptera, 1.

Integument, 100.

Integumentary glands, 101.

Integumentary cavities, 102.

Integumentary cavities, theu' number, 103, 104.

Intestine, structure of the wall of, 126.

Jarzynsky, Th., referred to, 3, 6.
Johnston, G., referred to, 1, 2, 134.
Joints of the legs, names, 16.,

EEPORT ON THE PYCNOGONIDA.

105

" Knight-Errant " species, description of, 94.
Kroyer, H., referred to, 3, 94, 134.

Lamarck, J. B., 2.
Larvfe, 139.
Lecythoi-hijiiclnts, 6, 9, 27.

cmnatiis, 27.

hilgendorfl; 27.
Legs, 16.
Linnaeus, C, referred to, 1.

Males, carrying the ova, 134.

Males, ovigerous function, exception to the rule, 135.

Male organs, 128.

Male genital pores, 129.

Male genital pores, their numher, 129.

Mandibles, 14, 15.

Metamorphosis, 140.

Miers, E. J., referred to, 4, 6, 51, 99.

Milne-Edwards, H., referred to, 2, 77.

Moseley, referred to, 10.

Nerves arising from the hindmost thoracic ganglion, 7.
Nerves arising from the commissiu'es between the

thoracic ganglia, 77.
Nerve, azygous proboscideal, 110.
Nerve, mandibular = an tenuary, 110.
Nerve, optic, 110, 111.
Nerve, integumentary, 112.
Nerve, for the ovigerous leg, 112.
Nerve, pal par, 121.
Nerves, paired proboscideal, 112, 113.
Nerves for the inner surface of the integunieut, 116.
Nerves arising from tlie thoracic gangUa, 117.
Nerve-rings in the proboscis, 114.
Nervous .system, 108.
Nymplwn, 2, 9, 10, 17, 36.

dbyssorum, 22, 97.

antarcticum, 19.

urmatum, 44.

hrachyrhyiichus, 7, 19, 47.

h-evicaudatuni, 7, 18, 49.

hrevicollum, 7, 19, 45, 147.

hrevirostris, 21.

brcvitarse, 21, 22.

compadum, 8, 23, 39, 41.

femovatum, Leach, 22.

femoratum, Eathke, 31.

fuscum, 7, 20, 48.

glaciale, 22.

giganteum, 19.

gracile, 11, 20, 65.

Nymplwn, gracilipes, Mier.s, 18, 19, 20, 43, 49.

gracilipes, Heller, 94.

grossipes, 3, 7, 20, 21, 44, 95.

hamatum, 8, 23, 36, 38, 54.

helleri, 18.

Mans, 22, 97.

hirsutum, 3, 18, 21.

hirfipes, 3, 17, 18.

hitimn, 17, 18.

hirtum, var. ohtusidigitum, 17.

hispidum, 49, 51.

horridum, 18, 49.

johnstoniannm, 34.

johnstonii, 22.

longiceps, 22.

longicolliim, 8, 20, 40.

longicoxa, 8, 23, 38, 42, 47.

longitnrse, 20, 41.

macronyx, 4, 7, 19, 38, 95.

macrum, 147.

megalops, 4, 20.

7neridlonale, 8, 11, 19, 43, 53.

mimduin, 22.

mixtwm, 20, 21.

piallenoides, 4, 18.

pelluciduin, 22.

peiiucidum, 8, 12, 20, 52.

phasma, 34.

phasmatodes, 23.

■procerum, 8, 23, 39.

robiisfum, 3, 7, 22, 97.

serrutum, 4, 21.

sluiterii, 21.

spinosimi, 22.

stroma, 7, 18, 19, 42, 48, 94, 97.

styligerum, 27.
Nymphonid/E, 17.

Oculifcrous tubercle, 15.
CEsophagus, 125.
CEsophageal ring, secondary, 114.
Oiccohathes, 4, 9, 25.

araclme, 25.
Oomerus, 4, 9, 34.

siigmatop)horus, 34.
Oorhynclnis, 9, 10, 27, 59.

aucJdandne, 8, 27, 59.
Openings, female genital, their shape, 132.
Organs of sense, 119.
Orithyia, 2.

coccinea, 32.
Ovaries, 131.

166

THE VOYAGE OF H.M.S. CHALLENGER.

Ovaries, number of, 13L
Oviduct, 132.
Ovigerous legs, 14, 15.
Ovigerous legs, functions of the, 15.

Pallene, 2, 9, 29, 30, 76, 82, 93.
attemiata, 32.
australiensis, 7, 30, 76, 79.
brevirosfris, 30, 65.
clielifera, 30.
chiragra, 30, 77.
circiilaris, 31.
discoidea 31, 169.
empusa, 30.
fluminetisis, 32, 81.
gruhii, 30.
hispida, 31.
intermedia, 31.
IcEvis, 78.

languida, 7, 30, 79.
lappa, 31, 82.
longkeps, 30, 81.
malleolata, 4, 31.
pygmcea, 33.
spinipies, 30.
PalleniDxE, 29.
Pallenopsis, 147.

forficifer, 147.
longirostris, 147.
Palpi, 14, 15.
Palpistes, 2.
Pantopoda, 17.
Parazetes, 6, 9, 26.

auchenieus, 26.
Parihoea, 5, 9, 26.

spinipalpis, 5, 26.
Pasithoe, 3, 5, 6, 9, 29.
vesiculosa, 29.
Pediculiis, 2.
Pephredo, 3, 9, 25.

hirsuta, 25.
Phalangium, 1.

grosdpes, 20.
litorale, 35.
spinosum, 35.
Phanodemm, 5, 9, 24.

collaris, 24.
horridus, 24.
inermis, 24.
Philippi, A., referred to, 4, 76.
Phoxichilidce, 34.
Phoxichilidium, 2, 9, 10, 29, 30, 31, 81, 92, 93, 147.

PlioxicMlidium ehiliferum, 4.

digitatwm, 33, 86.

femoratum, 31, 32, 84.

fluminense, 7, 32, 81, 88.

globosum, 32.

insigne, 7, 32, 82.

johnstoniaiium, 34.

lentum., 33.

maxillare, 32, 33.

minor, 32.

mollissimum., 8, 11, 33, 87, 89.

mutilatum, 32.

oscitans, 8, 11, 33, 88, 89.

patagoniciuii, 7, 11, 33, 84, 86.

patagonicmn,Yax. elegans, 7, 1 1, 33, 86.

petiolatum, 32.

pliasma, 34.

pilosum, 8, 11, 33, 37, 88, 90.

pygmwum, 33.

virescens, 33, 84.
PhoxicMlus, 2, 9, 29, 34, 35, 93.
inennis, 35.
tern, 4, 35.
meiidionalis, 35.
pigmceus, 35.
prohoscidcus, 3, 28, 98.
spinosus, 35.
Pigment in the subcuticular epithelium of Pallene

australiensis, 101.
Plates, explanation of, 149.
Platychelus, 5, 9, 25.

sardonicus, 25.
Podosomata, 17.
Proboscis, 14, 113.
Proboscis, development of, 139.
Pseudopallene, 5, 31.

hispida, 31.
Pycnogonids of the Arctic Ocean coasts, 3.
Pycnogonids of the Cape of Good Hope, 6.
Pycnogonids of the coast of Chili, 6.
Pycnogonids of the Cliina Sea, 5.
Pycnogonids of the Dutch coast, 4.
Pycnogonids of the Enghsh coast, 3.
Pycnogonids of Enosima, 6.
Pycnogonids of Franz-Josef Land, 99,
Pycnogonids of the French coast, 4.
Pycnogonids of the German coast, 4.
Pycnogonids of the Greenland coast, 3.
Pycnogonids of the Gulf of Naples, 5.
Pycnogonids of higher northern latitudes, 3.
Pycnogonids of the Japan coast, 6.
Pycnogonids of Kerguelen Island, 6.

EEPOET ON THE PYCNOGONIDA.

167

Pycnogonids of the " Kiiiglit Errant," 94.

Pycnogonids of last English Arctic expedition, 4.

Pycnogonids of the Mediterranean, 4.

Pycnogonids of jMozambique, 6.

Pycnogonids of Xew England, 5.

Pycnogonids of Xew England and adjacent waters,

147.
Pycnogonids of North America, 5.
Pycnogonids of the North Georgian Islands coast, 3.
Pycnogonids of Northern Europe, 3, 6.
Pycnogonids of the Northern part of the North

Atlantic, 4.
Pycnogonids of the Norwegian coast, 3, 4.
Pycnogonids of Port Blair, Andaman Islands, 6.
Pycnogonids of Kussian Lapland, 3.
Pycnogonids of the second German North Polar

Expedition, 3.
Pycnogonids of Singapore, 6.
Pycnogonids of the South Sea, 5.
Pycnogonids of the Straits of Magellan, 6.
Pycnogonids of the "White Sea, 3.
Pycnogonids of the " WiUem Barents," 94.
Pycnogonum, 2, 9, 35, 93.

uustrale, 36.

ehelatum, 24.

gwssipes, 44.

litorale, 7, 35, 99.

litorale, var. tenue, 36.

spinipes, 30.

Quatrefages, A. de, referred to, 4.

Range, hathymetrical, compared with geographical

distribution, 10.
Range in depth, 7.

Range, world-wide, of the deep-sea forms, 10.
RhopaJorliynclms, 6, 28.

kroyerii, 28.
Rhynchotlwrax, 5, 9, 24.

mediterranetis, 24.
Sars, G. 0., referred to, 4, 95, 97, 144.

Savigny, J. C, referred to, 2.
Savigny, referred to, 14.
Sabine, E., referred to, 3.
Scceorhynckus, 147.

arniatus, 147.
Scalpdlum, &]>., a commensal of Nymjjhoii rohustion,

98, 144.
Schobl, referred to, 130.
Semper, C., referred to, 13, 108, 134.
Setse on the integument, 102.
Sexual characteristics, external, 130.
Slater, H. H., referred to, 6.
Smith, referred to, 5.
Somatic cavity, 127.
Species, catalogue of the, 17.
Species, description of the Challenger, 36.
Spines on the surface of the body, 104.
Spines, denticulated ones, 104.
Spines, serrated ones, 104.
StLmpson, W., referred to, 5.
Summary of the Report, 145.

Tamjstylum, 6, 9, 27.

orbieulare, 27.

styligerum, 27.
Testis, 128.

Testis, microscopical structure of, 130.
Threads, given off by the glands in the foot-jaw of
the larvaj, 141.

Verrill, referred to, 5.

White, A., referred to, 5.
Wilson, E. B., referred to, 5, 82, 94, 146.
Wood-Mason, J., referred to, 5, 62.
WyviUe Thomson, C., referred to, 95.

Zenker, referred to, 100, 108.
Zetes, 3, 9, 25, 88.

hispiduH, 25.

spinosa, 26.

(ZOOL. CHALL. EXP. PART X. 1881.)

K 23

The Voyage of H. M.S." Challenger'

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