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son, FV, 1907. / a4
Coqgon ida, 1 4&
~ Ant. Exped.

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National Antarctic Expedition

Leon J. Cole Collection
WAS.NM. Acc. No. 153226

NATURAL HISTORY

VOL. III.

PYCNOGONIDA

STE AERTS EP IS

By 1. V. Hodgson, FL.S.

WITH TEN PLATES

Igo

ae
vy
i“

Leon J. Cole Collection
U.S.N.M. Acc, No. 153226

Eee NOG OWN LDA.

By T. V. Hopason, F.L.S.
(10 Plates.)

THE collection of Pyenogonids brought from the Antarctic by the ‘Discovery’ is a
large one, including as it does no less than twenty-eight species, three of which have
been assigned to as many new genera. Only one species can be regarded as of morpho-
logical importance, Pentanymphon antarcticum, which is now known to be abundant
and to have a circumpolar distribution. It differs from the genus Mymphon only in
the possession of an additional pair of legs. At first this was thought to be quite a
novel feature in the morphology of the Pyenogonida, but the Scotch expedition brought
another and much finer species from the South Orkneys. This proved to be identical
with Decolopoda australis, described by Hights some seventy years ago, and taken at
the South Shetlands. Eights’ work was lost for a long time, and though it has been
noticed recently by modern zoologists, the reception afforded it was extremely curious,
involving as it did the point-blank refusal to accept the possibility of the existence of
a Pycnogonid with more than the orthodox four pairs of legs. Mr. L. J. Cole (7), who
apparently looked with more sympathy on the work of a fellow-countryman, was the
first to appreciate this discovery properly. The genus Leionymphon was defined by
Professor Mébius for a large but immature specimen taken by the ‘ Valdivia’ in the
vicinity of Bouvet Island. It has been found necessary to re-cast this genus; as now
defined it contains no less than eight species, including two which had been assigned
to the genus Ammothea, and another which Professor Mébius thought should be placed
in the genus Colossendeis. No less than five species were taken by the ‘ Discovery,’
and four of them are new. No true member of the genus Ammothea was seen, but two
new species assigned to new genera, Austrodecus and Austroraptus, belong, as does the
genus Leionymphon, to the family Ammotheide as defined by Professor G. O. Sars.

Austrodecus is perhaps a close relation of Tanystylum, Miers, and is a curious little
form with a slender and elongated proboscis, like the snout of a weevil beetle, no chelifori,
six jointed palps, and small ovigers. Awstroraptus is remarkable for its spurred body
and the length of its legs.

Rhynchothorax australis is another curious form; the only other species of the
genus is found in the Mediterranean, but, notwithstanding certain differences, there
does not seem to be any justification for giving the ‘Discovery’ species other than
specific rank,

2 T. V. HODGSON.

The remainder of the collection falls into well-known genera, and does not call for
any special comment. A list is appended below of all the species now known from the
Antarctic and sub-Antarctic regions, those taken by the ‘ Discovery’ being marked with
an asterisk. The numerous islands scattered about the southern seas have long been
considered to pertain to the sub-Antarctic region, and for this reason I have made the
mean annual isotherm of 45° F., as indicated by Sir John Murray in the concluding
volume of the “Challenger Reports,” its northern limit. This includes all that can
reasonably be considered as belonging to this region, and coincides very closely with
the opinion expressed by Professor P. Pelseneer in his Report on the Mollusca of the
‘Belgica’ Expedition. For the Antarctic proper the latitude 60° 8. seems suflicient
as it includes all the glaciated lands of Antarctica, and the shallower waters less than
1000fm., connected therewith.

.

Antarctic. Sub-Antarctic.
Pycnogonum magellanicum, Hoek . : 2 - : 2 x

5 magnirostre, Mobius. : : : 4 : x
* Phoxichilus australis. : : : : : : : x
Pallene dimorpha, Hoek : : : : ; ; : x
* Pseudopallene cornigera, Mébius —. : : : F 4 x x
= 7 australis ; : : : ‘ . : x
Pallenopsis patagonica, Hoek. : : : :
bs i pilosa, Hoek c : é 3 : d 7 x
3 fluminensis, Kroyer : ;
* glabra, Mobius. : : ‘ : ‘ ‘ x
3 villosa : c F : : F , : x
35 hiemalis. : : : : , : 3 x
Anoplodactylus neglectus, Hoek
of petiolatus, Kroyer . ; ; : : :
Nymphon gracile, Leach 5 : : : : . 3
a gracilipes, Miers. F : : :
» brachyrhynchum, Hoek . : : :
. hamatum, Hoek
3 fuscum, Hoek :
Pr meridionale, Hoek .
3 antarcticum, Pfeffer
‘5 hiemale
lanare . A
3 adareanum
» frigidum : 6 : : ; : c
Cheetonymphon brevicaudatum, Miers. ; : : ‘ x
Pe villosum : : : :
55 biarticulatum
. mendosum :
es australe, Hodgson .
.. Pa var. austrinorum
* Pentanymphon antarcticum 5 - 5 ; : ;
Leionymphon striatum, Mébius —. , ‘ ; : : x
a grande, Pfeffer ‘ 3 ; ;
Pa gibbosum, Mobius. : : , ; : x
minus. ; F : : ‘ : x

MS caw

*

x
xX XX XK XK XK X

x

x * oe 8
x X X X

*

*

Ms OS KOS OK

*

PYCNOGONIDA. 3

Antarctic. Sub-Antarctic.

Leionymphon clausii, Pfeffer. . : 5 c ° ¢ x
PA australe . ; : : 5 . : : x
53 glaciale . : : ‘ : ‘ : ; x
Bs os spinosum : : : : 5 : c x
Ammothea hoeki, Pfeffer : : 5 3 ; ; : x
3 wilsoni, Schimkewitsch F ‘ ‘ 5 A 4
5 communis, Bouvier F P F 3 : : x
4 curculio, Bouvier 5 : ‘ . , : <
Tanystylum styligerum, Miers é 6 : : : : x
is dohrnii, Pfeffer . F ; ‘ ; ; : x
- chierchix, Schimkewitsch . : ; ; ; x
* Austrodecus glaciale. : : : : : : : x
* Austroraptus polaris. : : é : : : 5 x
Ascorhynchus glaber, Hoek . : é ¢ ‘ 3 : x
* Rhynchothorax australis ; : . : : ; : x
Colossendeis gigas, Hoek x
oo leptorhynchus, Hoek x
i gigas leptorhynchus, Hoek x
3 megalonyx, Hoek <
- robusta, Hoek x
53 gracilis, Hoek x
= % australis x
* sy glacialis x
Le = frigida x
- 9 rugosa : ¢ x
Decolopodaf australis, Eights x
5 antarctica, Bouvier x

No less than seven expeditions have taken part in the recent ‘Siege of the
South Pole,” and the collections of Pyecnogonids made by four of them still remain
unpublished. This being the case, it is scarcely desirable to enter into a discussion
on the geographical distribution of these animals. It may, however, be stated that
the head-quarters of these animals appears to be in southern seas. — Professor Mobius
(22) has compiled a list of the known Arctic and sub-Arctic species, which
number forty-two. In the same work, for comparison, he has added a list of all
the species taken beyond 30° South latitude. Only thirty-one species are included
in this large area, and the genus Zunystylum is the only one occurring in the south
which does not occur in the north. I have reduced the Southern or Antarctic area
to what I consider more reasonable dimensions, and the ‘Discovery’ collection, with
its predecessors, raises the total tu sixty-three species. Among these species there are
five new genera; four of these are, as far as is yet known, confined exclusively to
the Antarctic region, the other extends well into the sub-Antarctic region. The
“Bipolarity Theory” is only affected by a single species, Colossendeis australis. Of
all the numerous species of this genus, C. proboscidea, from the north, and C. australis,
from the south, stand apart from all the rest on account of their bodily form, and
there can be no question that they are much more nearly related to each other than

t [As Eights said his species had “ five perfect pairs” of legs he doubtless meant to write Decaholopoda.—Ep. |
B 2

4 T. V. HODGSON.

to any other members of the genus. The two species, as species are recognised
now-a-days, are perfectly distinct, but it is a fair question to ask how is their
present position at the opposite ends of the earth to be accounted for ?

As to the terms employed in the following work, some words of explanation
are necessary.

Naturalists have not always used the same terminology, and Mr. L. J. Cole (6)
has recently tabulated the essential variations. As, however, the terms used by
any one naturalist have not been fully adopted, and others have been introduced,
a complete account of the terminology used here is given.

The entire Body of a Pycnogonid is divisible into three regions—the proboscis,
trunk, and abdomen—and this without regard to any of the appendages. Where
the body only is alluded to, it is to be understood that both the trunk and abdomen
are taken together. Measurements are taken dorsally, unless otherwise specified,
except in the case of the appendages, which are generally measured from the side,
and the length of the trunk is usually taken to the base of the abdomen ; in exceptional
cases, where the abdomen is vertical or very short, the trunk may be measured to
the extremity of the posterior lateral processes, but this is so stated. Its width
is always across the longest of the lateral processes.

The Cephalon is regarded as that portion of the trunk which lies in front of
the first pair of lateral processes, and the so-called neck is the narrowest part,
sometimes elongated, between those processes and the more expanded distal portion.

Segmentation is not regarded as perfect or complete unless the four segments
of the trunk and the abdomen are distinctly articulated.

The first appendage of the trunk is the Cheliforus, also commonly known as
the mandible. A considerable amount of confusion has been, and is still likely to
be, caused by the fact that the chela has most frequently been regarded as a single
joint. Obviously it consists morphologically of two joints, and in order to avoid any
misapprehension as to the number of joints, this appendage has been described as
chelate, or otherwise, and the scape, a name given by Professor G. O. Sars to the shaft
supporting the chela, has been recorded as one- or two-jointed, as the case might be.
This method of dealing with the limb is suggested in order to avoid confusion as
to the number of joints it possesses.

The second appendage is the Palp.

The third appendage is the Oviger. This convenient name was given by

ce

Mr. L. J. Cole to replace the more cumbrous term “ ovigerous,” or “ false leg.” = In
these two appendages the various joints are numbered from the base, and not named.
5 : ’
The remaining four or five pairs of appendages are Legs pure and simple; with

‘

the use of the word ‘oviger,”’ the qualification “ambulatory” or “ walking leg”
s 1 g les

becomes quite unnecessary. The terms used for the individual joints are those

adopted by Professor G. O. Sars, viz., first, second and third coxa, femur, first and

second tibia, tarsus and propodus.

PYCNOGONIDA. 5

A projection beyond the insertion of the terminal claw, which occurs in some
species, is called the Heel, a term introduced by Mr. L. J. Cole. Two other expressions
have been adopted for purposes of convenience. In very many species, not to say
genera, there occurs a thickening of the skin on the sides of the legs, not infrequently
also on some of the other appendages ; this takes the form of a narrow and conspicuous
line, usually of a reddish colour, and so it has been termed the “lateral line.” The
other feature concerns the sete. At the extremity of most of the joints there is
a fringe of more or less specialised setee, sometimes surrounding the joint, but
frequently more conspicuous on the dorsal or the ventral aspect. This has been termed
the distal fringe, a name which does not appear to be inappropriate.

Precise measurements are invariably necessary with regard to the legs. One
leg is generally considered to be sufticient for this purpose, and as Dr. P. P. ©. Hoek
adopted the third leg of the right side for this purpose wherever possible, the same
‘limb has been used here.

PHOXICHILUS.

This genus is readily distinguished by its slender form and the complete absence
of chelifori and palps. The ovigers too only occur in the male, and are seven-jointed.
Among other characters may be mentioned the presence of a “collar” between the
cephalon and the proboscis. This, however, is deficient in the species described below.

Numerous species have been assigned to this genus, but the difficulties of species
discrimination is increased by the absence of two of the normal number of appendages,
and necessitates some modification of the generic characters. No less than six species have
been described from European seas, but their specific distinctness is open to question.
Three others have been found in distant seas, and a fourth now described is from the
extreme south.

PHOXICHILUS AUSTRALIS.
(Plate I, fig. 1.)

Specific characters :—
Body slender, with lateral processes very widely separated and with the long legs completely
covered with very minute stiff setae.
Tarsus with a very prominent ventral spine, and three to five proximally on the propodus,
which projects distinctly beyond the insertion of the terminal claw and auxiliaries.
No distinct collar anteriorly to cephalon.

Body slender, with the lateral processes long and very widely separated ; perfectly
smooth to unassisted vision, but with a 1-in. objective extremely minute spines can be
detected ; segmentation very prominent and immediately behind each pair of lateral
processes. :

The Cephalon is small, but stouter than the trunk, truncated anteriorly with the
angles bevelled off. No collar exists as such, but a band of thin chitinous skin,
characteristic of an articulation, occurs between the cephalon and the base of the
proboscis.

6 T. V. HODGSON.

The Ocular tubercle lies almost in the middle of the cephalon, but scarcely clear
of the first pair of lateral processes. It is very stout, of no great elevation, terminating
in a strong cone above the four eyes.

The Abdomen is small, cylindrical, terminating in a cone, and directed almost
vertically upwards. It is not articulated to the trunk.

The length of the trunk is 5mm. (to extremity of posterior lateral processes) and
its extreme width is 3mm.

The Proboscis is long and slender, scarcely 4mm. in length, flexibly united to the
trunk. It is cylindrical, but very slightly swollen before the middle and equally
slightly narrowed before its rounded extremity. The mouth is inconspicuous, but of
normal size. The proboscis is covered, more especially distally, with extremely
minute spines.

The Legs are long and slender, attaining a length of 30mm. The first coxa is the
smallest, and the second is a trifle longer than the first and third together ; the pro-
portions of the three following joints are as 8 : 6°75 : 8°5; the tarsus is very small, and
the propodus, which is curved, is about a quarter the length of the femur. The entire
limb, as the trunk, is completely clothed with extremely minute stiff setee, which for
the most part are only visible with a powerful lens. On the tibia they are, however,
rather more conspicuous, besides being most abundant. The larger or ventral surface
of the tarsus is covered with short spines, but one distal one is extremely large and
prominent. Dorsally the propodus is covered with the minute stiff sete, ventrally there
are at the proximal end of the joint three to five very large spines, the remainder of
that surface being occupied by a band of much smaller though still conspicuous
spines of rather irregular size. A prominent heel projects over the insertion of a
powerful terminal claw and its two auxiliaries, these latter being about half its length,
but much more slender. The second coxa bears dorsally, just beyond the middle of its
length, a tubercular enlargement, which is perforated by a glandular opening.

The genital apertures occur on a transverse ridge at the extremity of the second
coxa of every leg. Ventrally, in the angle formed by the first pair of lateral processes
and the trunk, there is a very small but distinct process on each side, exactly in the
position where the oviger should be.

This type specimen is a female, and was taken off Flagon Point in Winter Quarters
in 5-20 fm., on very rough ground.

Two other females were taken, one slightly larger than the type came from
125 fm., on a bottom composed of small stones and organic débris ; the other is much
smaller, but the precise point at which it was captured in Winter Quarters remains
uncertain. A fourth specimen is a male, and is to a considerable extent overgrown
with polyzoa. This specimen was taken at the same time and place as the type. It
is sexually mature, and the genital apertures occur on the three posterior legs only.
The ovigers are well-developed, but unfortunately only four basal jomts remain on
either side. They arise in the angle formed by the first lateral process and the trunk,

PYCNOGONIDA. 7

but not on a body process ; the first joint is small, the second is a little longer, the two
following which are longer still, the fourth is largest. The appendage bears a moderate
number of minute setz.

I have been unable to distinguish the cement glands on the femur as described
and figured by Professor G. H. Carpenter for other species. (4 and 5.)

PSEUDOPALLENE.

This genus, established by Mr. E. B. Wilson in 1878, has been more completely
defined in accordance with modern requirements by Professor G. O. Sars (25). It is
very closely allied to Cordylochele (G. O. Sars), but the special features which
distinguish it from that genus are (a) the crown of sete at the distal extremity of the
proboscis ; () the presence of spines on the body and legs.

Two species are now described, one of which I regard for the present as identical
with those derived from the ‘ Valdivia’ and ‘ Frangais’ Expeditions.

PSEUDOPALLENE CORNIGERA.
(Plate I., fig. 3.)
Pseudopallene cornigera, Mobius (23). p. 186.
Cordylochele turqueti (?), Bouvier (2). p. 297.

Specific characters :—
Body with long lateral processes not very widely separated, these armed ders with a stout

spur. A pair of similar spurs on the cephalon.

Legs with longitudinal rows of sete set in small tubercular bases. Propodus well covered with
setee and a proximal group ventrally of half-a-dozen spines.

Oviger ten-jointed. Denticulate spines with three strong teeth at the base.

Body rather robust, with long lateral processes not very widely separated. The
length of these processes is increased by a very prominent spur which occurs dorsally
on each.

A very conspicuous spur occurs on the antero-lateral border of the Cephalon.
This is rather long, with a definitely constricted neck, and widens considerably into two
lobes bearing the chelifori, and between which the proboscis arises.

The Ocular tubercle is short and stout, rounded above, and bears four well-
developed eyes. It lies between the first pair of lateral processes and the neck.

The Abdomen is of normal proportions, gently tapering, and not articulated to the
trunk. It is directed upwards, but does not extend beyond the posterior lateral
processes, and bears a few minute setee. The segmentation is distinct.

The length of the body is 6mm., and its extreme width is barely 5mm.

The Proboscis is ventral in origin, rising apparently from a pocket between the
chelifori, directed obliquely downwards. It is a little longer than the cephalic segment
gently tapering toa blunt point, the small triangular mouth being surrounded by a

tuft of small bristles.

8 T. V. HODGSON.

The Chelifori are well-developed; the scape is single-jomted, about two-thirds
the length of the proboscis, enlarged at its distal extremity, and carries a few minute
sete. The chele are massive, curved almost to a right angle near their bases, and
thickly covered with minute sete. The fingers are short and massive, the immovable
one bears two tubercles distally, but the movable one has none.

Palps are not present, but on either side of the cephalon ventrally, and just outside
the chelifori, there is a small mark, an indication of where they should be. The antero-
ventral margin of the cephalon is a slightly curved line.

The Oviger (fig. 3) is ten-jointed, and is built on much the same lines as in the
genus Nymphon, It arises on a very small body-process between the neck and the first
lateral process. The first three joints are small and progressively increase in length,
the third being slightly curved and having a very oblique distal termination. The
fourth joint is rather longer than the three preceding ones together ; it is stout, curved,
and like them, scantily supplied with small sete. The fifth joint is very long and
slender ; owing to the curves it is difficult to measure precisely, but it appears to be as
long as or longer than the preceding four joints. Its distal half bears a bunch of
about forty large eggs, and is terminated by a short lobe. The sixth joint is quite
short; the seventh and eighth are longer and sub-equal; the ninth and tenth
progressively shorten, but only by a very little, the last one being slightly curved.
The terminal claw is worn down to a stump, but appears to have been slender. The
four terminal joints each bear a row of denticulate spines and a few small sete
dorsally. ‘The spines are much worn, and only a flattened ovate leaf can be dis-
tinguished, with traces of three or four lateral teeth.

Fig. 3a is from a younger specimen.

The Legs are not very long, only attaining a length of about 23mm. Of the three
cox the second is quite as long as the other two together, and is enlarged distally.
The first shows a trace of a distal spur which gives it a rather angular appearance, and
the setz of the distal fringe arise for the most part on tubercular enlargements of the
joint. On the second coxa the sete are linear and dorsal, those of the mid-dorsal row are
socketed into small tubercular enlargements of the joint. The third coxa bears a few
small sete dorsally, and a poorly developed distal fringe ventrally. The three following
joints are very nearly equal in length, cic. 5mm., but the advantage is with the second
tibia. On the femur there are five rows of sete dorsally and laterally, three of which
are readily seen, the sete usually arising from a small tubercle; the other two rows are
less conspicuous and contain fewer sete. In the mid-ventral line there is a row of
comparatively stout tubercles. On the two tibize the setee are very much more
numerous, and their linear arrangement and tubercular bases are less distinct. They
cover both dorsal and ventral surfaces, but a space above the lateral line is left bare.
The lateral line is distinct from the first coxa to the end of the second tibia. The
distal fringes, though present, are composed of setee of moderate size, and are therefore
inconspicuous. The tarsus is very small and cup-shaped, its ventral surface being

PYCNOGONIDA. 9

completely covered with stiff seta, largest distally. The propodus is curved, with a
very distinct swelling ventrally at the proximal end; this swelling bears half-a-dozen
strong spines, the rest of the ventral surface being occupied by a band of stout spinous
sete about half the size of the proximal group. Dorsally the setee are fewer and
weaker, a narrow space appears devoid of them laterally. The terminal claw is long
and slender, about two-thirds the length of the propodus, to which it is articulated at
the ventral angle. There are no auxiliaries, and the projecting heel is small.

The Genital apertures of the male occur on the second coxze of the two posterior
pairs of legs; in the female they occur on all the legs, on a conspicuous swelling of
the coxa.

The adult male bearing ova, described above, was taken in Winter Quarters in
125 fathoms, on a bottom of small stones and organic débris (June 6, 1903). A
smaller specimen, taken’ at the same time and place, is rather severely mutilated, having
lost one of its ovigers and four legs. Its sex is indeterminable, but it is probably
immature. The first segment of the trunk is distinct; the others can be traced, but
with difficulty. The limbs are much more spinose than in my type ; everywhere the
tubercular enlargements from which the stiff setee arise are more abundant, especially
on the first coxa and the femur. The oviger also is very different. The first three
joints are small, the third having an oblique termination which involves half its length ;
the fourth is as long as the two preceding, the fifth a trifle longer; the sixth is very
short, and the seventh scarcely twice as long. Of the three terminals the middle one
is the shortest, the other two being subequal in length. From the sixth each successive
joint becomes more slender. The entire appendage is completely devoid of sete, but
on the inner margin of the seventh joint are three curved spines; on the eighth joint
there are two, and on the terminal one there are six, one of them occupying the position
of the terminal claw. An adult female was taken in 41 fms. (Jan. 30, 1903). The
femora contain ripe ova and are swollen in consequence. The setz are generally
finer than those of the male. The oviger, too, resembles that of the male. The
denticulate spines are fairly well preserved, and under a high power (}" obj.) show :
short shaft with three small, but strong, teeth. Then follows a flattened ovoid blade
with a minutely toothed margin, the teeth of which are of a totally different character
to those on the shaft. On the terminal joint these spines are more curved than
elsewhere and the terminal claw does not exist, its place being taken by a much worn
example of the denticulate spines. Another occurs more dorsally, but is broken off in
this specimen.

I believe I am correct in identifying these specimens with the P. cornigera of
Professor Mobius and with the Cordylochele turqueti of Professor Bouvier. Though |
have seen both species, I must admit that I have not examined them with that care that
the fact of a second closely allied species having been found demands.

The essential difference between the ‘Discovery’ and the ‘ Valdivia’ specimens
occurs in the length of the legs, which are half as long again in the latter specimens.

c

10 T. V. HODGSON.

PSEUDOPALLENE AUSTRALIS.

(Plate L, fig. 2.)

Specific characters :—
Body with lateral processes widely separated, these and the cephalon armed with stout spurs.
Limbs armed with rows of prominent tubercles which bear the sete. Propodus with few setie
dorsally and a proximal group of three or thereabouts.
Oviger ten-jointed, four terminal joints long and cylindrical. Denticulate spines without lateral
teeth at base.

Body rather robust, though more slender than in the last-named species; lateral
processes widely separated, and but little longer than the trunk is broad. It is
smooth except for the spurs on the cephalon and lateral processes. These are similar
to but more upright than those of P. cornigera. The segmentation is distinct.

The Ocular tubercle is short, stout, rounded at the extremity, and bears four
large well-developed eyes. It rises just clear of the first pair of lateral processes.

The Abdomen is of normal proportions, rather ovoid in shape and without sete.
There is no articulation, and it is directed obliquely upwards.

The length of the body is 6mm. and its extreme width is 3mm.

The Proboscis and the Chelifori are as in the preceding species.

The Ovigers (fig. 2a) rise just behind the neck, each from a small body-process.
The first joint is very small and stout, the second equally stout, but much longer; the
third is more slender, and has the usual oblique termination, but is scarcely as long
as the two preceding joints; the fourth is nearly as long as the three preceding.
The fifth is much the longest of the appendage, slender and rather enlarged distally.
The sixth is quite small, about a quarter the length of the fifth. All these joints bear
a very few minute sete, all of which have traces of an enlarged base. The four
terminal joints are long and slender, with very little difference in their length; the first
is longest, the next two are subequal, and the last the shortest. All are provided with
numerous denticulate spines, which occur in a single row (fig. 2b). They comprise a
rather conical shaft, surrounded by a flat leaf-like blade with a finely dentate margin.
There is no trace of the stout basal teeth so characteristic of the preceding species.
The end of the terminal joint bears two curved spines, which are obviously the same
denticulate spines worn down. The character of these four terminal joints differs from
those of the preceding species in their more slender and cylindrical form as well as their
oreater length.

The Legs extend to a length of 23mm. Of the three coxe the second is quite as
long as the other two together; the proportions of the three following joints are as
6:5°5:5°5; the tarsus is very small, the propodus is curved, especially proximally,
and rather more than one-third the length of the second tibia. The terminal claw is
very long and slender; there are no auxiliaries, nor is there any heel. The sete, if
such they may be called, are small and delicate. They lie in lines parallel to the
surface of the joint, and, with very few exceptions, each one occurs on a prominent

PYCNOGONIDA. il

tubercular process arched towards the extremity of the limb. They occur distally on
the first coxa, dorsally on the second, where there are two rows, and ventrally on the
third coxa. Elsewhere there are five rows in which the ventral tubercles are the
smallest. Between the two rows on the second coxa distally is a rounded tubercle
bearing no seta. The distal extremity of the second tibia is liberally provided with
small stout sete not connected with tubercles; its distal fringe is inconspicuous.
The tarsus is covered with sete which increase in length distally, forming a fringe of
long and stout sete. The tubercular character of the leg completely disappears on
this and the succeeding joint. On the propodus there is a scanty supply of minute
sete dorsally, and ventrally at the proximal end of the joint is a well-developed
enlargement bearing three spines of moderate strength; the rest of the ventral surface
is occupied by a band of small but fairly prominent spinous sete.

A single specimen of this species was taken off the Barrier, lat. 78° 25'40" S., long.
185° 39’ 6” KE. in 300fms. Bottom, mud.

It is an adult female, with the Genital apertures prominent on the second coxe of
all the legs.

PALLENOPSIS.
“ Body slender or robust, distinctly segmented.
Proboscis cylindrical, ventral in origin, flexibly united to the trunk.
Abdomen long and slender.
Chelifori well developed ; scape long, two-jointed.
Palps reduced to a more or less conspicuous knob.
Ovigers ten-jointed, present in both sexes, without a terminal claw or denticulate spines.
Legs with auxiliary claws. A tubular duct occurs in a mid-ventral position on the femora of the

male.
Ocular tubercle placed anteriorly on the cephalon, with two unequal pairs of eyes. -

As above stated, the generic definition is much altered from the original of Prof.
EK. B. Wilson (32). Besides the two new species described below, no less than thirteen
have from time to time been recorded, all of them from a strictly limited number of
specimens. They are separated by characters which, when committed to paper, do
not appear as definite as one would like. Nothing is known with regard to the
variation which may occur within the limits of ‘‘a species,” and so it must remain open
to question whether I have taken the right course with reference to P. Aiemalis and

P. pilosa, Hoek, or not.
PALLENOPSIS GLABRA.

Pallenopsis glabra, Mobius (23), p. 184.
Specific characters :—
Body comparatively slender, with lateral processes widely separated, and with two small tubercles
dorsally.
Chelifori well developed, scape two-jointed, the whole limb minutely scabrous.
Palps reduced to a conspicuous stump.
Ovigers ten-jointed, without claw or denticulate spines.
Legs long, covered throughout with minute spinous setz.

12 T. V. HODGSON,

T am unable to find any satisfactory grounds for separating this species from that
of Professor Mobius. A full description follows, as that of Professor Mébius is scarcely
sufficient on small points. Body comparatively slender, with the lateral processes
widely separated and slightly increasing in length to the third, which is directed back-
wards.

The Cephalon is long, rather broader than the rest of the body, bevelled
anteriorly to form a median point, immediately behind which lies the stout ocular
tubercle. This is stout, erect, rounded in front, and terminating in a short spine on
the posterior half of the tubercle above the eyes. The four eyes are well developed,
the anterior pair being much the larger. The Ovigers arise on small body-processes
immediately in front, and rather below the level of the first lateral pair.

The Abdomen is very long, slightly curved, and with a clavate extremity ; it is
not articulated to the trunk, and is directed obliquely upwards at a considerable angle.
It is covered with minute curved spines.

The segmentation of the trunk is rendered conspicuous by a slightly raised ridge
forming the posterior border of the segment, these ridges are rather more prominent
ventrally, and in both cases bear a few minute spines. Similar spines occur on the
lateral processes, and form a distal fringe round them.

The Proboscis is movably articulated to the trunk and directed downwards, its
origin is ventral, and at the proximal end of the cephalon; it is cylindrical, tapering
slightly, its distal extremity rounded and the mouth small. It is completely covered
with minute spines except for a narrow band in the mid-ventral line.

The Chelifori are well developed, and arise close to the middle line, their origin
occupying almost the entire width of the cephalon. The scape is two-jointed, and half
as long as the trunk measured to the base of the abdomen ; the two joints are sub-equal
in length, the second being expanded distally. The chela is directed downwards, the
palm rather curved, and fully as long as the other joints. The small dactyli are directed
inwards, the movable one having a spinous cushion at the base. The entire appendage
is covered with minute spines, largest and most numerous on the second joint of the
scape, the distal fringe of which is also more conspicuous.

The Palps are stout single-jointed stumps arising from the sides of the cephalon,
about the middle of its length.

The Oviger is ten-jointed. The first joint is very short and stout, the second is
much longer, clavate and setose on its outer margin; the third is shorter, curved, and
having a very oblique termination ; it is also setose on its outer margin. These three
joints form a curve in one direction, and the following three curve in another. The
fourth and fifth joints are comparatively long and sub-equal, both slightly curved, the
fourth setose on both sides, the fifth only on its outer margin; the sixth joint is short
and much curved, and from this one the remaining joints become shorter, more slender,
and more setose, the set being longer than elsewhere. There is no terminal claw, nor

denticulate spines.

PYCNOGONIDA. 13

The Legs are long, attaining a length of 69mm. The lateral line is conspicuous,
beginning on the lateral processes and extending to the end of the second tibia. Of
the three coxze the second is longer than the other two together, all three are thickly
covered with small spinous sete on the ventral surface, but, except on the first coxa,
there are none dorsally. The proportions of the three following joints are as 17 : 14°5 : 21.
The femur is fairly well covered with minute set ventrally; dorsally they are much
less numerous, except at the distal extremity. A linear arrangement of the sete is
observable, but it is not very regular, a distal fringe is not very prominent, and almost
confined to the dorsal side. On the first tibia the setee become more numerous dorsally,
they preserve the same general arrangement, but there are longer setee mixed with them.
On the second tibia this becomes much more pronounced, and ventrally the sets are so
numerous that the linear arrangement is completely obscured ; the distal fringe on both
joints is well developed, more especially so on the ventral side of the second tibia. The
tarsus is very small, the ventral surface being double that of the dorsal; the former is
covered with long spinous sete, most prominent distally, like those of the distal fringe
of the preceding joint, dorsally they are smaller, but form a well-developed fringe. The
propodus is slightly curved, and completely covered with small spinous setee, and some
of these form a distal fringe over the insertion of the terminal claw and its auxiliaries.
At the proximal end of the joint is a series of some half-dozen short spines, the centre
ones being the largest ; beyond these a group of stout spinous setee extends to the end
of the joint. The terminal claw is short, half the length of the propodus, and the
auxiliaries are about half its size.

Of the two specimens obtained one is a male, and the Genital apertures occur on
a slight swelling at the distal extremity of the second coxee of the two posterior pairs of
legs. On the ventral surface of the femur is a swelling about the middle of its length,
and this bears a short but stout duct characteristic of the males of this genus. The
Genital apertures of the female occur on a very pronounced swelling, in a similar
position to those of the male, but on all the legs.

This specimen is remarkable for having the first leg of the right side complete in
all essential details, but not extending beyond the distal extremity of the femur of the
normal limb.

Winter Quarters, off Flagon Point. January 17th, 1903. 5-20 fm. Very
rough ground.

PALLENOPSIS VILLOSA.
(Plate II., fig. 1.)

Body robust, with lateral processes rather close together. Entire animal clothed with long,
slender sete, giving it a woolly appearance.

Chelifori well developed, scape two-jointed, no setous cushion at the base of the dactylus.

Palps reduced to a knob.

Oviger ten-jointed, without claw or denticulate spines.

Legs densely clothed with fine sete, propodus with several strong spines ventrally ; one or two
of the proximal ones are much the largest.

14 T. V. HODGSON.

Body robust, with the lateral processes distinctly, but not widely separated.
Segmentation is complete, and in the case of the trunk it is rendered very prominent
by each segment to some extent overlapping the following one ; this is most noticeable
ventrally.

The Cephalon is large, with a distinctly constricted neck. At its extreme anterior
end, which is straight, the stout rod-like ocular tubercle projects slightly forwards ;
this is rounded at its extremity, where there are four well-developed eyes, the anterior
pair very much larger than the posterior.

The Abdomen is long and distinctly articulated to the trunk; it increases in
diameter to a short distance from its extremity, when it abruptly tapers to a blunt
point. About its middle it is provided with a considerable number of long slender
setee. Similar sete fringe the anterior border of the cephalon, the distal extremities
of the lateral processes, and the posterior border of each segment. None of these
setee are present ventrally. The length of the body is 10mm., and its width is 6*5mm.
The abdomen measures barely 4mm.

The Proboscis is stout, cylindrical, rounded at the extremity, and articulated to the
trunk on the ventral surface, and therefore directed downwards. The mouth is small.
It is liberally covered with short setee. In length it is scarcely half that of the body.

The Chelifori are long and chelate; they arise quite close to the middle line
underneath the anterior border of the cephalon. The scape is stout and two-jointed,
measuring some 5mm. in length; the two joints are sub-equal and covered with long
slender sete, the second joint more abundantly so, especially distally. These setze are
confined to the dorsal surface ; a row exists ventro-laterally, but ventrally they are
replaced by very short sete. The third joint, forming the chela, is directed down-
wards, and is shorter than the preceding. It is covered all over with sete, shorter
than the average, but varying in length from the proximal to the distal end; on the
outside of the movable finger is a dense tuft of long sete (fig. la). The dactyli are
turned inwards, the movable one being the longer. They are curved at the tips, which
cross over each other, and are devoid of teeth.

The Palps arise at the side of the proboscis, and are nothing more than rounded knobs.

The Ovigers are ten-jointed, and without terminal claw or denticulate spines
(fig. 1b). They arise ventro-laterally between the base of the proboscis and the first
lateral processes. All the joints are small, and the appendage is curved like an
attenuated S, and setose throughout. The first joint is small and stout, the remainder
gradually decrease in breadth; the second is about twice as long as the first; the
third is intermediate between the two, and has a very oblique termination. These
three joints bear long sete on the outside of the curve formed by them. The fourth
joint is the longest on the appendage, and slightly curved ; it bears a few long setee on
the inner side, and numerous short ones on both. The fifth joint is not so long, also
slightly curved and dilated distally with long setz on its outer side. The sixth joint
is shorter and slightly curved ; it is thickly clothed with long sete, and bears a few

PYCNOGONIDA. 15

on the opposite side distally. The seventh, eighth, and tenth joints are sub-equal
in length, and the ninth is a little shorter. The arrangement of the sete is the same
as on the sixth joint, except that the distal group on the outer side increases on each
Joint, so as to involve the whole of it. The sete on the five terminal joints are very
long and quite simple.

The Legs are very stout, and some 36mm. in length. The first coxee are about as
long as their corresponding lateral processes ; the second are longer, and, in the female,
bear a conspicuous enlargement ventrally near the distal extremity, upon which the
large genital openings occur ; these are on all the limbs. The third coxe are about
the same size as the first. The three following joints differ but little in size, being
proportionally as 8°5:9:9°5. The tarsus is very small, and the propodus is about
a quarter the length of the second tibia. The entire limb is clothed with sete.
Dorsally the three coxze each bear a prominent distal fringe of long sete. The first
has two lateral bands in addition, while the other two are more completely clothed.
Ventrally the third coxa is partially covered with small sete, and has a prominent
distal fringe of longer ones, the other two only possess a distal fringe of short
sete. On the femur the dorsal surface is covered with long sete, which also form a
prominent distal fringe ; the ventral surface bears only small sete, but on each side
there is a band of the large ones just below the well-developed lateral line. This
arrangement holds good on the two tibie, but the sete are much more thickly
set. At the distal extremity of the second tibia the setze become spinous ventrally,
and as spines form the distal fringe on that side. The ventral surface of the tarsus is
clothed with spines which are large distally ; dorsally there is a fringe of sete only.
The propodus is covered dorsally with sete of more moderate length than those on
the appendage generally ; laterally they are smaller still, and along the ventral
aspect there is a row of about a dozen strong spines, a little irregular in size,
but one or two of the proximal ones are much the largest. There is no projection of
the propodus beyond the insertion of the terminal claw, which is stout and rather
more than half the length of the joint that bears it. It is accompanied by two small
auxiliaries.

The single specimen is an adult female, and contains ripe ova.

Taken off Coulman Island in 100 fm., on mud and stones, January 13th, 1902.

PALLENOPSIS PILOSA.
(Plate II., fig. 2.)

Phoxichilidium pilosum, Hoek (14), p. 90.
Pallenopsis pilosa, Hoek (16), p. 9.
Specific characters :—
Body not very robust, with lateral processes not widely but distinctly separated. Body (dorsally)
and legs covered with extremely long thin hairs.
Chelifori well developed, scape showing distinct articulation on the dorsal surface. No setose
pad at base of dactylus.

16 T. V. HODGSON.

Body fairly robust, with lateral processes distinctly, but not widely, separated ;
two pairs directed forwards and the other two backwards.

Cephalon stout, longer than two segments of the trunk, cylindrical, with its
anterior border bevelled on each side; near the point thus produced lies the Ocular
tubercle. This is short and stout, capped by a blunt point below which are four well-
developed eyes; the anterior pair larger than the posterior pair.

The Abdomen is long and slender, terminating in a blunt point, and bearing
numerous lone sete.

The segmentation of the body is perfect, and on the posterior margin of the three
anterior segments are two tufts of long slender sete, a number of which occur also
on the lateral processes, and also form the distal fringe. The ventral surface is devoid
of sete.

The length of the body is 10mm., its width 5mm. The abdomen measures 4mm.
in length.

The Proboscis is ventral in position, directed downwards and movably articulated
to the trunk. It is cylindrical, terminating in a blunt cone; mouth small, covered
with small setze 4mm. long.

The Chelifori are well developed; they arise close to the middle line in front of the
cephalon, and extend considerably beyond the proboscis. The scape is long and single-
jointed, though dorsally there is a slight enlargement about the middle of its length,
indicating a possibly fused joint. Numerous long and slender setz are distributed over
the scape. Distally the setze are smaller, and there is a strongly developed distal
fringe. The chelz are comparatively small, and hang vertically. The palm is scarcely
more than a quarter the length of the scape, covered with short stiff sete. The fingers
are small, and directed inwards at a considerable angle from the palms; the movable
finger is nearly twice the size of the other, but neither bears any trace of teeth.

The Palps are quite rudimentary, being nothing more than a small but conspicuous
rounded stump at the side of the proboscis, well behind the ocular tubercle when
viewed from the dorsal aspect. They bear a few small sete.

The Ovigers occupy a lateral position immediately in front of a shallow groove
separating the cephalon from the first lateral processes. They are ten-jointed (fig. 2).
The first joint is small and stout; the second is about three times as long, enlarged
distally ; the third is intermediate in length between these two; the fourth is long,
about as long as the two preceding joints, and very stout; the fifth is very little longer,
slightly narrowed in the centre, and expanded distally; the sixth is stout, and not
half the length of the fifth. All these joints bear a few short sete, most numerous on
the outer side of the fifth and sixth joints. The seventh joit is longer than the
sixth or the two following together; of these the proximal is shorter, the terminal
joint (missing in the appendage examined in detail) is quite small and without a
terminal claw. The last four joints bear long and stout sete of a simple character.
There are no denticulate spines.

PYCNOGONIDA. 17

The Leg attains a length of 832mm. Of the three coxee the second is about as
long as the other two together, and is much enlarged distally. The first bears a
mid-dorsal row of a few long setee and a distal fringe of the same kind. The second
bears two dorso-lateral rows and the distal fringe ; and ventrally, a conspicuous fringe
between the distal extremity and the genital apertures. The third coxa is covered
ventrally and laterally with setee and carries ventrally a very prominent distal fringe.
The proportions of the three following joints are 8°5 :8°5:10, these joints are covered
with lines of very long slender sete, their great length making it difficult to determine
the precise number of rows. On the femur they are most abundant ventrally, except
near the distal extremity. On the two tibize the ventral surface is much more scantily
supplied. The distal fringe of the second tibia is rather spinous ventrally. The
tarsus is very small, setose, and with a few spinous sete at its ventral extremity.
The propodus is curved, covered with rather short sete, a fringe of longer ones distally ;
there is no heel. Ventrally at the proximal end of the joint are two or three stout
spines, and a band of smaller ones of irregular size extends to the end of the joint.
The terminal claw is long and slender, with two well-developed but not large auxiliaries.
Small setze also occur more or less abundantly throughout the limb.

The Genital apertures of the female occur on the enlarged part of the second coxa
of every leg. In the male these orifices occur at the apex of a pointed tubercle on the
two posterior legs only. The male as a rule is more setose than the female, and on
the mid-ventral surface of the femur there is the duct so characteristic of the males of
this genus ; in this species it is long and slightly twisted, conspicuous even among the
long sete. The joints of the ovigers up to the sixth joint are more strongly developed,
longer, and all are more setose than those of the female. One specimen has three
perfect ovigers, two on one side being in contact with one another. The eggs are
rather large, and held round each oviger in a single rounded mass.

Several specimens of this species were taken off the Ice Barrier in the Ross Sea,
300fm., mud bottom. I am unable to find any satisfactory reason for separating them
from the species of Dr. P. P. C. Hoek. They are smaller, and the only character which
ean be used to separate them is the comparative length of the four terminal joints of
the oviger, but this does not seem to me to be suflicient.

PALLENOPSIS HIEMALIS.
(Plate L., fig. 4; Plate II, fig. 3.)

Body well built, with lateral processes widely separated, but of variable length, and having a
tubercular swelling at the dorsal extremity.

Chelifori and abdomen both proportionally long.

Palps, a rather long stump.

Legs clothed with short, stiff sete.

Body well built, with the lateral processes rather widely separated, as long as the

trunk is broad, and each bearing distally a stout tubercle of no great elevation.
D

18 T. V. HODGSON.

The Cephalon is elongated, but not much enlarged in diameter, with a very
slightly constricted neck between the first pair of lateral processes and the small
body-processes from which the ovigers arise, and which are plainly visible dorsally.
The anterior margin of the cephalon is angular, and the Ocular tubercle arises at its
front. This is stout, directed very slightly forwards, and terminates in a point above
the four well-developed eyes ; the anterior pair are larger than the posterior.

The Abdomen is long, not articulated to the trunk, and slightly enlarged before
it terminates in a blunt point; it is directed upwards to a moderate extent. The
length of the body is 11mm., its width 4:75mm., and the length of the abdomen is
375mm. A few small, stiff setee occur dorsally at the posterior margin of the segments
and at the extremity of the lateral processes.

The Proboscis is stout, cylindrical, rounded at the extremity; the mouth is
small. Ventrally it measures 4mm. in length and, except in the mid-ventral line, it is
closely covered with small, stiff setee. It is ventral in position, directed obliquely
downwards, and articulated to the trunk.

The Chelifori are well developed, and arise close together above and in front of the
proboscis. The scape is long and stout, projecting beyond the extremity of the proboscis,
though only 4mm. long. It is divided by a distinct joint into two sub-equal portions
and covered completely with short, stiff setae; the second joint is expanded distally
and has an oblique termination. The chela is well developed, the palm being rather
shorter than the joints of the scape, but like them densely setose. The dactyli are
set on its inner extremity and lie transversely. They are short and stout, smooth
without teeth ; the movable one is the larger, and has a setose pad at the base.

The Palps are stout, single-jointed, rather long stumps; they arise from the sides
of the cephalon about the middle of its length.

The Ovigers are ten-jointed, without terminal claw or denticulate spines (fig. 4a).
The appendage arises on a small process of the body in front of the first lateral
process. The first joint is short and very stout; the second is at least twice as long,
slender proximally, much dilated distally ; the third is shorter, and the oblique
articulation of this joint with the next renders the fourth to all intents and purposes
lateral; the fourth is the longest of the appendage and stout; the fifth shorter,
and the sixth shorter still. The limb is curved in the form of an §, the first three
joints forming the curve in one direction, the three following curve in another.
Of the four terminal joints the seventh is short, the eighth is longer, the ninth and
tenth progressively shorten. The entire appendage is setose, the sete are small
and rather sparse proximally, becoming more numerous to the fifth joint ; from that
joint onward they are longer, but quite simple, and more completely clothe the joints.

The Legs extend to about 388mm. Of the three cox the second is fully twice as
long as the other two together, and bears a low rounded tubercle dorsally, just beyond
the middle of its length. The first coxa carries dorsally a stout but short tubercular
process, similar to, but smaller than, that of the lateral process. The proportions of

PYCNOGONIDA. 19

the three following joints are 9:8°5:11°5. The tarsus is very small, and of the
normal shape. The propodus is one-third the length of the femur, very slightly
curved. At the ventral side of the extremity is a stout claw, with two well-developed
auxiliaries ; the heel does not project beyond the insertion of these claws. The joint
is uniformly clothed with short spinous sete, and there is dorsally a projecting fringe.
Ventrally there is a row of stout spines, of which some half-dozen, not very regular
in their position, are very prominent (fig. 3). The entire limb is uniformly and
densely clothed with very short, stiff setee, and these, as is usually the case, are more
numerous and longer on the second tibia; the distal fringe on this latter jomt
is prominent, with at least one stout spine ventrally. The ventral sete on the tarsus
are also spinous, one being particularly large. The lateral lme is very prominent
from the lateral processes to the tarsus, both inclusive.

The specimen is a female and bears Genital apertures on a swelling of the second
coxa of every leg.

Winter Quarters, inside the 20-fm. line.

A specimen was taken off Cape Wadworth, Coulman Island, which, notwithstanding
certain important differences, I cannot regard as being specifically distinct. It is a
male, and rather larger than the type. The obvious differences le in the much
greater length of the lateral processes and the character of the ventral spines on the
propodus (fig. 3a). With regard to the first of these features, the third lateral process
of the right side is but little more than half the length of the others ; the first coxa, the
only joint of that appendage that exists, is also abnormally small, though there are no
definite traces of injury. The other feature rests on the armature of the propodus.
The ventral surface of this joint bears proximally three very stout spines, and from
there to the extremity is a band of spinous setze.

The length of the body is 12mm., of the trunk only 9mm., and its extreme width
is 6mm., rather larger, especially in the last measurement, than the type. The
chelifori (scape) and the abdomen are a little shorter. The oviger differs only in
being much stronger; the setee are more numerous and also stronger. The fifth joint
is however longer, nearly equalling the fourth. This is a not uncommon sexual
difference. The lateral processes and the first coxa exhibit in a less degree the
tubercular processes of the type.

The proportions of the three principal joints of the legs are 9°75 :8°5, and 12,
a difference of no importance. These limbs are setose throughout, though the setze
are rather deficient proximally, becoming much more abundant on the tibia. Ventrally
they are very small, stiff, and crowded ; dorsally much less numerous. They have among
them a number of much longer and more slender setw. The tarsus 1s coarsely setose
ventrally, with one very prominent spine. The distal fringes of the jomts are not
strongly developed ; that of the second tibia is chiefly ventral and spinous. The lateral
line is very distinct from the lateral process to the end of the second tibia. The femur
is swollen ventrally near the middle, and bears a very short but stout tubular duct.

D 2

20 T. V. HODGSON.

Another specimen, a male, was taken in Winter Quarters, inside the 20-fm. line,
before the ship was frozen in. It is in a severely mutilated condition, having lost the
posterior segment of the trunk and several legs. It differs slightly from the male
above described, the lateral processes being a little closer together and the body,
especially the cephalic portion, being a trifle stouter, and the tubercular knobs on
the lateral processes not being so distinct, but all these features can, I think, be
readily accounted for by age.

This species is closely allied to P. patagonica, Hoek.

NYMPHON.

This genus is perhaps the most widely distributed and best known of all the
genera of Pyenogonida. It is readily distinguished from all others by the well-
developed chelifori, the five-jointed palps, and the ten-jointed ovigers, the four terminal
joints of these being provided with a single row of denticulate spines. The form of
the body varies greatly within certain limits, and Professor Sars (25) has subdivided

the genus into three :

Nymphon retains the more slender and comparatively long-legged species.

Cheetonymphon the more robust and short-legged species, which also, as a rule, are
more setose on the body than those of the original genus, Nymphon.

Boreonymphon, another robust form, readily separable from the others by the
absence of teeth on the chelew, the spines of the ovigers being simple and not
denticulate.

The species brought back by the ‘Discovery’ are eight in number ; four are
assigned to the original genus, though one of these, N. adareanum, bears a few simple
spines on the oviger instead of the rows of denticulate spines. The other four, of
which one, for the present at least, is regarded as a southern variety of a previously
described species, are assigned to the genus Chetunymphon.

NYMPHON HIEMALE.
(Plate III., fig. 1; Plate X., fig. 8.)
Specific characters :-—
Body slender, with rather long lateral processes very widely separated. Limbs covered with very
minute sete.

Ocular tubercle stout and short.
Palps five-jointed, proportions of last three as 7 : 4 : 5°5.
Oviger ten-jointed, denticulate spines rather numerous, with eight to ten teeth on each side.
Legs long, scabrous, terminal claw with well-developed auxiliaries.

Body smooth, slender, with rather long lateral processes, which are very widely
separated; the first of these is curved forwards. The segments are very strongly
marked immediately behind the lateral processes.

The Cephalon is long, the greater part of its length is taken up by a slender

PYCNOGONIDA. 21

neck; anteriorly it is much expanded, the two lobes being separated by a small but
conspicuous groove.

The Ocular tubercle is situated immediately in front of the first lateral
processes ; it is comparatively stout, short, truncate, and bears four well-developed
eyes without any pigment.

The Abdomen is small, ovoid, does not project beyond the last pair of lateral
processes, and is not articulated to the trunk. The length of the body is 7-5mm. and
its width is almost 4mm.

The Proboscis is cylindrical, smooth, and directed obliquely downwards ; it is
about 3mm. in length.

The Chelifori are well developed. The scape is as long as the proboscis, slightly
curved and sparsely covered with minute sete ; the distal fringe is not conspicuous.
The chelz are also curved, half their length being taken up by the palm, which
is finely setose, the sete extending on to the base of the immovable finger. The
fingers are slender, much incurved at the tip. The teeth are numerous and regular
in size, not so closely set in the immovable finger as in the other.

The Palp is slender, five-jointed, and rises at the side of the proboscis below the
chelifori (fig. la). The first joint, as usual, is very small; the second is the longest of
the appendage, slightly swollen distally, and sparingly covered with minute sete. The
third joint is but a little shorter, rather stouter, and more liberally supplied with
short sets, though these are still scanty. The fourth joint is scarcely half as long
as the second, very richly supplied with short sete on its ventral margin, much
more sparingly dorsally. These three joints have a well-defined distal fringe. The
terminal joint is nearly half as long again as the preceding and, like it, richly clothed
with short setee ventrally, more sparingly dorsally.

The Oviger is ten-jointed, and arises ventro-laterally in front of the first lateral
process on a prominent body-process, the position of which is clearly seen from the
dorsal surface (fig. 1b). The first three joints are small and stout, the third
curved and having a very oblique termination; only a distal fringe of very
small sete can be detected on these joints. The fourth joint is very long, slightly
curved, with very few minute setee besides the distal fringe. The fifth joint is
much the longest of the appendage, and is thinly covered with very small sete,
with a more strongly marked distal frmge. The sixth joint is little more than
half as long as the preceding, slightly curved, and thickly clothed with small
stiff setee on its outer side and a well-developed distal fringe. The four terminal
joits are long, progressively decreasing in length, but the last two are sub-equal.
All are more or less well supplied with short stiff sete dorsally and a distal fringe
of rather longer sete. The terminal claw is long and slender, with about fourteen
eurved teeth. The denticulate spines are long, and in the specimen critically
examined occur 13 : 10: 10: 9 on the various joints. (Plate X., fig. 8.) The shaft is
flattened and slender, and carries eight to ten teeth on each side; the third or fourth

22 T. V. HODGSON.

from the base is the largest, the remainder tapering off to very minute proportions.
The eggs are small and the spherical mass is packed round the proximal part of
the fifth joint.

The Legs are long and slender and attain a length of about 45mm. The second
leg of the right side has in this case been selected for measurement. Of the
coxe the first and third are sub-equal, the second being quite as long as the
other two together. The proportions of the three following joints are as 10:11: 16,
and the tarsus and propodus taken together are 4°5, the former joint being a little
the longer of the two. <A lateral line is plainly visible on the femur and to the
end of the leg. On the femur such setze as exist are extremely minute; on the
second tibia they are very numerous but small, arranged principally dorsally and
ventrally, with a distinct distal frmge. On the tarsus and propodus the arrangement
is the same, but the sete are even more crowded. Ventrally on the propodus is a
row of about a dozen comparatively strong spines, more distally than proximally.
There is a distinct heel friged with rather long sete. The terminal claw is stout
and accompanied by two auxiliaries about one-third its size.

The Genital apertures of the male are found on the second coxe of the two
posterior legs, those of the female being found on all the legs.

A number of specimens were taken in Winter Quarters in 125 fm.

=

NyYMPHON LANARE.
(Plate ILI., fig, 2; Plate X., fis. 95)

Specifie characters :—
Body very slender, with lateral processes long and widely separated.
Ocular tubercle short and stout.
Palps five-jointed, proportions of last three 10:9: 11.
Oviger ten-jointed, denticulate spines, about double the number on the first joint as on any of
the others, with five to seven teeth on each side.
Legs long and slender, with long and fine sete, terminal claw long, without auxiliaries.

Body very slender, with lateral processes long and very widely separated.

The Cephalon is long, expanded anteriorly into two lobes separated by a narrow
eroove. The neck is elongated, and at its base, ventrally, are small body-processes
for the attachment of the ovigers, visible from the dorsal aspect.

The Ocular tubercle is short, stout, and truncated ; it les immediately in front, but
not quite clear of the first pair of lateral processes. It bears four well-developed eyes.

The Abdomen is quite small, and does not extend as far as the posterior lateral
processes. It is directed slightly upwards, and not articulated to the trunk. The
length of the body is 8°5mm., and its width 5mm.

The Proboseis is cylindrical, slightly swollen in the middle, its extremity being
rather angular. Together with the body, it is quite devoid of sete.

The Chelifori are well developed, long and slender. The scape is single-jointed,

longer than the proboscis, but scarcely as long as the chela. It bears but few sete,

PYCNOGONIDA. 23

except a distal fringe of long and slender ones. The palm of the chela occupies
about half its length, and bears a number of fine setee dorsally. The fingers are
long, slender, incurved at the tips, and provided with numerous slender teeth,
irregular in size and not very closely set.

The Palp arises laterally at the side of the proboscis (fig. 2a), and comprises the
normal five joints, all of which, except the first, are very long and slender, the pro-
portions being 10: 10:9: 11. Sete are non-existent on the first two joints; on the
third scanty, most numerous on the terminal joint, but not very thickly distributed
there ; they are small, rather delicate, and occur mainly on the outer side of the limb.

The Oviger has the normal ten joints, and arises on a small ventro-lateral body-
process just in front of the first pair of lateral processes (fig. 2b). The first three joints
are small, but progressively lengthen, the third having the usual oblique termination.
The fourth joint is long, the fifth longer, and the sixth still long, though the shortest
of these three, the proportions being about 7: 8:5. The sixth joint is rather thinly
covered with small setze on its outer side, and has a well-developed distal fringe.
The preceding joints have so few minute setee between them that they are scarcely
noticeable. Of the four terminal joints, the first is about twice the length of the next ;
the other three differ very little in size, but the middle one is the smallest. All are
provided with a few small sete and distal fringes. The terminal claw bears a dozen
slender teeth rather closely set. The denticulate spines form a single row (plate X.,
fig. 9). They consist of a stout shaft, which begins to taper at about a quarter of its
leneth, where the denticulations begin. Of these there are from five to seven; the
first is small, the next three large, and the remainder more or less vestigial. Of
these spines there are 10 : 5 : 4 : 5 respectively on the various joints.

The Legs are long and slender, attaining a length of nearly 45mm. The three
coxe are long, the second being longer than the other two together ; these joints are
rather scantily clothed with setee of no great length. The proportions of the followmg
joints are 8°5.:9°5 :12:4:3. The terminal claw is very long and slender, more than
half the length of the propodus, and there are no auxiliaries. The limb is clothed with
setee, not very closely set, in a linear manner. On the femur and tibia they are very
long and slender, becoming reduced in size on the tarsus, while on the propodus they
are very small.

Two examples of this species were taken off the Barrier in 300fm., bottom mud,
27th January, 1902.

NYMPHON ADAREANUM.
(Plate IIL. fig. 3.)

Specific characters :—
Body smooth and slender, with lateral processes widely separated.
Ocular tubercle short, rounded.
Palps five-jointed, proportions of last three 2°5 : 1°25: 1°75.
Oviger ten-jointed, without denticulate spines, but with very few simple curved spines.
Legs of moderate length, with rather long sete, terminal claw with two well-developed auxiliaries.

24 T. VY. HODGSON.

This small species has a fairly well-built body, with the lateral processes rather
widely separated, and as long as the diameter of the trunk. The trunk articulations
are very distinct, and immediately behind the lateral processes. No setee of any kind
are to be seen on the body.

The Cephalon is stout but not widely expanded, showing two distinct lobes for the
reception of the chelifori; it is not quite as long as the second and third trunk
seoments together.

The Ocular tubercle is very stout, of small elevation, rounded at the summit, and
carries four well-developed eyes. It lies just in front of the first pair of lateral
processes and behind the neck.

The Abdomen is of moderate dimensions, curved upwards, and not separated by
an articulation from the trunk.

The length of the body is 2°75mm., and its extreme width 1°5mm.

The Proboscis arises on the ventral side of the trunk, and measured ventrally it
is nearly one-third the length of the entire body. It is stout, gently tapering to a
rounded extremity, quite smooth.

The Chelifori are well developed; the scape is single-jointed, extending beyond
the proboscis ; provided laterally with comparatively long sete. The chela is not very
long, the palm and fingers occupying approximately equal halves; the former is
covered with sete, and the fingers, rather curved, are supplied with a very moderate
number of slender teeth rather widely separated.

The Palp is five-jointed, and rises underneath the chelifori (fig. 3a); as usual, the
first joint is very small and the second long. Owing to distortion in mounting this
appendage, the comparative length of the second and third joints cannot be very
accurately stated, but the second appears to be twice the length of the third; the
fourth is half the length of the third, and the fifth is longer than the preceding, the
proportions being 5: 2°5:1'25:1°75. The terminal joint is ovoid, and fairly well
supplied with comparatively long sete ; the three preceding joints have well-developed
distal fringes and a small number of sete scattered along the shaft; these are most
numerous on the third joint.

The Oviger is ten-jointed, and rises from a small process of the trunk, visible
dorsally, just in front of the first pair of lateral processes (fig. 3b). The first three
joints are very small; the second and third are subequal in length, the latter much
the more slender; the fourth is longer than the three preceding ones together; the
fifth is twice as long, much curved, and bears a few setee on its outer margin; the
sixth is half as long as the fourth. The four terminal joints are very small, the first
being the largest, and all bear two or three long set distally. The terminal claw is
long and slender, with five slender teeth set at irregular intervals. Of denticulate
spines, such as characterise the genus Nymphon, there are none, but of special spines
there are 2:2:2:1 on the four joints; these are curved blades without any other
distinguishing feature.

PYCNOGONIDA. 25

The Legs are not very long, extending to nearly 11mm. from the trunk. Of the
three coxee, the second is as long as the other two together, the first being by a little the
smallest ; the proportions of the remaining joints being 4:5:6:0°75:2. The terminal
claw is large and stout, with two well-developed auxiliaries. The lateral line is distinct
throughout. The sete have a rather indistinct linear arrangement, those on the
sides of the coxee are prominent, especially on the second; on the third they are more
confined to the ventral surface, and the distal fringe is fairly well developed. On the
femur the setz are long and straggling, chiefly lateral, and ventrally there is a row of
small tubercles. On the two tibize, but more especially the second, the setze are most
abundant, largest on the first. | Ventrally they are much smaller, the distal fringe of
the second tibia becoming spinous. The tarsus is a very short joint with long sete
dorsally, smaller and more numerous ones ventrally, which become delicate spines
distally. The propodus is covered with setze dorsally, and ventrally there is a row of
rather strong spines, and of these the middle ones are strongest.

The single specimen is a male, carrying young, apparently just hatched. The
Genital apertures are to be found on the second cox of the two posterior pairs
of legs.

From the root of a Laminarian taken in 17 fm., Cape Adare, 24th February, 1904.

NYMPHON FRIGIDUM.
(Plate III., fig. 4; Plate X., fig. 10.)

Specific characters :—
Body very slender, with lateral processes long and very widely separated.
Ocular tubercle very short, stout.
Palps five-jointed, proportions of last three 3 : 1:5: 3.
Oviger ten-jointed, denticulate spines not very numerous, with five to seven lateral teeth.
Legs long and slender, propodus with ventral row of spines, a large terminal claw and two
auxiliaries.

Body well built, perfectly smooth, with the lateral processes widely separated and
rather long, much more slender than the trunk.

The Cephalon is rather long, with a distinct neck and expanded anteriorly into
the two normal lobes.

The Abdomen is short, directed obliquely upwards, and not projecting beyond
the posterior pair of lateral processes.

The Ocular tubercle is stout, very short, and bears four well-developed eyes.

The length of the body is 2mm., and its extreme width is 1*2mm.

“The Proboscis is cylindrical, directed downwards.

The Chelifori comprise a single-jointed scape, slender, and covered with a small
number of fine setee. The chelze are well developed, the palms being about half their
length, and setose ; the fingers are not much curved, provided with a number of teeth,
not very closely set, and of uniform size.

The Palp is five-jointed and rises underneath the chelifori (fig. 4a). The first

E

26 T. V. HODGSON.

joint is small, and the proportions of the remainder are 4:3:1°5:3. The terminal
joint is well supplied with sete on the outer side, and the preceding one is similarly,
but less well, provided. Elsewhere they are scanty, a few on the third, and only an
occasional one on the second.

The Oviger is ten-jointed, and rises from a small process immediately in front of
the first pair of lateral processes (fig. 4b.) The first joint is very small, the two
following are longer and subequal, the third having as usual a very oblique termination.
The fourth and fifth joints are subequal, and each much longer than the first three
together ; the sixth is half as long as the preceding. Of the four terminal joints the
first is the longest, the rest differ but little, but the last is longer than the others,
and bears a terminal claw with some half-dozen teeth. A limited number of sete
occur on all the joints from the end of the fourth. The denticulate spines are not
very numerous, 8:5: 4:5, and consist of a slender tapering shaft with from five to
seven lateral teeth ; the second from the base is strongly developed, the rest graduated
to nothing (plate X., fig. 10).

The Legs are long and very slender; they are about 9mm. long. Of the three
cox the second is longer than the other two together, the proportions of the remaining
joints being 4:4°5:7:1:1°5. The terminal claw is more than half as long as the
propodus, and is accompanied by two slender auxiliaries. The entire limb is rather
thinly clad with sete, which, as usual, are most abundant on the second tibia. The
propodus bears ventrally a row of comparatively strong spines, not very regular, the
middle ones being generally best developed.

This is not a mature form, and the sexual apertures cannot be distinguished. I
am unable to identify it with Nymphon hiemale, though it occurs in the same locality,
and feel compelled to regard it as an independent species.

CH&®TONYMPHON VILLOSUM.

(Plate IV., fig. 1; Plate X., fig. 11.)
Specific characters :—
Body robust and with the appendages covered with long and fine set ; lateral processes close
together.
Ocular tubercle rather tall, with four eyes at summit.
Palp five-jointed, proportion of last three 6 : 2:3.
Oviger ten-jointed, denticulate spines not numerous, having five to seven lateral teeth on each side.
Legs short, with a strong terminal claw and two well-developed auxiliaries.

Body very robust and, with the appendages, covered with long and fine sete.
The lateral processes are close together, and these, being stout, give the body a compact
ovoid form.

The Cephalon is short, much expanded, and the neck, which thereby becomes
distinct, is scarcely a real constriction, the expanded portion being divided into two
distinct lobes, bearing a few long sete distally. Similar sete occur dorsally on

PYCNOGONIDA. 27

each segment of the trunk and on the lateral processes, in addition to the distal
fringe. There are none ventrally.

The Ocular tubercle rises from the neck immediately in front of the first pair of
lateral processes ; it is moderately tall, cylindrical, and bears at its rounded summit
four well-developed eyes.

The Abdomen is long and slightly ovate; it projects beyond the first coxee of the
posterior pair of legs in their normal position, and bears a few small setze.

The length of the body is 6°5mm. and its width is scarcely 4mm.

The Proboscis is stout, cylindrical, and inclined downwards ; it is quite devoid of
setee of any kind, and 2°5mm. long, measured dorsally.

The Chelifori are strongly developed; the scape is stout and single-jointed ; it
bears on its inner margin a band of long setze and a distal fringe of similar sete, but
these are much reduced in size on the outer side. The chela is strong, the palm is
setose all over and well on to the base of the immovable finger. These sete are of
normal size. The fingers are inclined at a considerable angle with the palm, and are
curved at the tips, especially the immovable one. Both are provided with numerous
slender teeth, not very closely set, and variable in size; these teeth may be said to
be large and small, but they are not disposed with any regularity.

The Palp has the normal five joints and arises at the side of the proboscis
(fig. la). The first joint is very short and stout; the second is the longest; this is
stout, dilated, curved at its distal extremity, sparsely covered with long setee and much
more abundantly with fine ones. The third joint is nearly as long, as 8 to 10,
and more abundantly supphed with both kinds of sete, which occur throughout
the appendage. The fourth joint is short and richly setose; the fifth is about half
as long again as the fourth, and also richly setose.

The Ovigers arise ventro-laterally, immediately in front of the first pair of lateral
processes (fig. 1b). Of the orthodox ten joints the first three are quite small, the
last being slightly curved, longer than either of the other two, and with an oblique
termination. The fourth joint is long, the fifth is longer still, the sixth about half
the length of the preceding. All these joints are covered with very fine set; on
the first four there is an occasional longer and coarser seta, and on the fifth joint these
are more conspicuous on the outer margin and distal extremity ; on the sixth joint
they cover it on the outer side and form a well-developed distal fringe. Of the four
terminal joints the first three progressively shorten without any conspicuous difference
in size; the terminal one is a little longer than the preceding, and bears a slender
curved and dentate claw half as long again ; there are eleven slender teeth on the claw.
The denticulate spines are not numerous on these joints, 5: 4:3: 4, and are of the normal
type, the shaft bearing five to seven lateral teeth. The spines on the proximal joint
are the largest. (Plate X., fig. 11.)

The Legs are short and robust, only attainmg a length of 17mm. Of the three
eoxe the second is a little the largest ; they all bear a few long sete dorso-laterally, the

E 2

28 T. V. HODGSON.

third coxa being the most deficient in this respect. The distal fringe is well developed
ventrally on the second coxa, but more so on the third, and the ventral surface of this
joint is covered with small setee. The femur is short and stout, approximately equal
in size to the second tibia, the first being a little longer. The sete on these three
joints are arranged in a thoroughly characteristic manner. There are two dorso-lateral
rows and a lateral row, all of long, slender setze. There is also a ventral row of com-
paratively short sete, five rows in all. The seta are much better developed on the
second tibia than elsewhere. The distal fringes on these joints are normally
developed ; on the tibize they are ventral and spinous, more especially on the second
tibia. The tarsus and propodus are short and much more slender than the rest
of the limb. The two joints differ but little in size, the propodus being a little
the longer. This bears a stout terminal claw and two well-developed auxiliaries.
The sete of these two joints are small, but have the same arrangement as on the
other joints. The ventral row is, however, distinctly spinous, and a very prominent
spine exists at the ventral end of the tarsus.

Only one individual of this species was taken, and its sex has not been determined.

Coulman Island, 13 January, 1902; 100 fathoms, stony bottom.

CHETONYMPHON BIARTICULATUM.
(Plate-IV., fic, 25; Plate 2X3 fig. 12.)

Specific characters :—

Body stout, tapering posteriorly, articulation deficient, lateral processes separated by variable
intervals.

Ocular tubercle long and slender.

Palps five-jointed, proportions of last three as 8:1: 1.

Oviger ten-jointed, denticulate spines not numerous, and with not more than five small teeth on
each side.

Legs of moderate length, covered with rather fine sete, terminal claw with small auxiliaries.

Body is stout and tapering posteriorly, with the lateral processes separated by a
moderate interval, except the last two pairs, which are quite close together, the articu-
lation between them being deficient. The distal extremities of the lateral processes are
provided with slender spines, but these have enlarged bases and thereby become more
prominent.

The Cephalon is short and stout, a very distinctly constricted neck separating
the expanded portion, which forms two diverging lobes.

The Ocular tubercle lies immediately behind the neck and in front of the first
pair of lateral processes. It is tall, slender, cylindrical, and bears four well-developed
eyes at the extremity ; there is no pigment.

The Abdomen is rather long, narrow, tapering to a blunt point, and not separated
from the trunk by an articulation.

The entire body is covered with very fine sete, not easy to distinguish, and in
addition there are two long sete dorsally near the posterior border of each segment,

PYCNOGONIDA. 29

two on each of the cephalic lobes, and one in the middle of each lateral process; these
also possess dorsally a distal fringe of stout setee with enlarged bases. The ventral
surface appears to be quite devoid of sete.

The length of the body is 9mm. and its width scarcely 5mm. The length of the
trunk only (to base of abdomen) is 6mm.

The Proboscis is stout, cylindrical, and has a length, measured dorsally, of 3mm.
It is covered with very fine but comparatively long sete.

The Chelifori are well developed. The scape is single-jointed, reaching beyond the
proboscis; it is stout and provided with rows of sete having very stout bases
and a few others as if misplaced. The distal fringe is very prominent, especially on
the inner side. The chela approximately divides its length between the palm and the
fingers ; the former is covered with short and comparatively fine seta, and these are
continued well on to the base of the immovable finger. The fingers are inclined
inwards, slender, much incurved at the tips, and furnished with a number of slender,
closely-set teeth of fairly regular size.

The Palp arises laterally immediately below the chelifori (fig. 2a). The first joint
is small and stout, the second is long, and extends nearly to the end of the proboscis ;
the third is shorter; the two terminal ones subequal and together shorter than
the third, the proportions of the four joints being 5:3:1:1. The second joint is
uniformly covered with fine sete, as are the others. The setee become more numerous
and both longer and stiffer towards the extremity of the appendage.

The Oviger rises ventro-laterally immediately in front of the first lateral process ;
it consists of the normal ten joints, and is covered throughout with very fine delicate
sete (fig. 2b). Other and stiffer setze occur sparingly on the fifth joint, more
numerously on the sixth and the distal fringes of most of the joints, particularly the
terminal ones. The first three joints are small, but progressively lengthen, the third
having a very oblique termination. The fourth is a trifle longer than the first three
together, the fifth is longer still, and the sixth is half the length of the fifth. The
four terminal joints progressively shorten, the third being practically half the length of
the first; the terminal one bears a slender curved claw, as long as itself, with nine
slender teeth. The denticulate spines are not numerous, 7: 5:4: 4 (Plate X., fig. 12).
They consist of a flattened tapering shaft with not more than five lateral teeth on each
side, none of them large, and occurring nearer the base than usual, leaving the terminal
portion of the shaft free. They do not appear to be much worn.

The Legs are not very long, extending to about 25mm. Most of the joints are
very stout, but the tarsus and propodus are considerably reduced in diameter. Of the
three cox the second is the largest, but not so long as the other two together ; the
proportions of the remaining joints are 5°5:6:5°5: 3:2. The entire limb is clothed
with fine setze, but in addition to these are conspicuous rows of Spinous sete arising
from enlarged bases. Two dorso-lateral rows occur on the first two coxe, two rows
occur dorsally on the femur, but here the spines are small; the two lateral rows are

30 T. V. HODGSON.

much larger; but ventrally, this joint and the coxe also are covered with normal sete.
These spines are best developed on the first tibia, two dorsal and two lateral rows
being conspicuous, a ventral row of much finer spines occurs. On the second tibia all
these five rows occur, but the spines are rather finer. The sete of the two terminal
joints are small without the enlarged bases, but arranged in the same manner. The
terminal claw is long and slender, and is accompanied by two quite small auxiliaries.
The distal fringes of the various joimts do not present any unusual features.

The single specimen is a female, the Genital apertures are conspicuous on the
second coxee of all the legs.

Off the Barrier. January 27,1902. 300 fms. Mud.

Lat. 78 25°40" 'S., long. 1857 39! 6" sk

CH&TONYMPHON MENDOSUM.

(Plate IV., fig. 3; Plate X., fig. 13.)

to}
Specific characters :—
Body robust and tapering, articulation imperfect, lateral processes not widely separated, and with
stout spines distally and dorsally ; no fine setze whatever.
Ocular tubercle short and stout.
Palp five-jointed, proportions of last three 5-5 : 1°5 : 1°6.
Oviger ten-jointed, denticulate spines few, with four teeth on each side, two of them prominent.
Legs with five rows of spinous sete, without enlarged bases ; terminal claw with two small
auxiliaries.

This species is very closely allied to the last, but is much smaller, and presents
other differences which are usually regarded as of specitic rank.

The Body is robust and slightly tapering, with stoutly developed lateral processes,
the intervals between which are variable, widest but not very wide between the first
and second pairs; the third and fourth being quite close together, the articulation
between the two posterior pairs is not present.

The Cephalon is short, anteriorly expanded into two diverging lobes; the neck
is distinct, but very little constricted.

The Ocular tubercle lies behind the neck, but not clear of the first pair of lateral
processes.

The Abdomen is horizontal, long, extending considerably beyond the first coxa,
ovoid, tapering to a blunt point ; it completely fills the space between the two posterior
lateral processes. All this is in close agreement with the preceding species. The
differences are :—The complete absence of fine setee from the entire body; the ocular
tubercle is rather short, stout, and slightly inclined forwards, carrying four well-
developed eyes with pigment on its rounded summit; the lateral processes all
provided with two or three stout spines dorsally and distally ; the spinous sete of the
legs, while having the same arrangement as in the preceding species, are, on the whole,
stronger in themselves, but without the enlarged bases.

The length of the body is 6°5mm., and its width just exceeds 3mm.

PYCNOGONIDA. 31

The Proboscis is of moderate length, 2mm., measured dorsally, cylindrical but
slightly swollen in the middle ; it is directed downwards, and not setose at all.

The Chelifori are well developed ; the scape is single-jointed, stout, and scarcely as
long as the proboscis. A row of stout spines runs along its inner border, and a few
spinous sete constitute a distal fringe, and there are two or three scattered on the
shaft. The chela is strong, the palm taking up half its length, and the fingers are
set at a considerable angle. The palm is covered, but not thickly, with sets. The
fingers are slender, curved towards the tip, and provided with slender teeth of fairly
uniform length, but not very closely set.

The Palp rises laterally, quite close to the proboscis, and consists of the normal
five joints (fig. 3a). The first is short and stout, the second is the longest of the
appendage and provided with a few long sete; its proportion to the remainder is
9:5°5:1°5:1°6; the third is scantily supplied with sete, the two terminal joints are
rather more abundantly supplied ; the last joint is ovoid instead of cylindrical.

The Ovigers arise ventro-laterally immediately in front of the first pair of lateral
processes. They comprise ten joints of normal character (fig. 3b). The first three
joints are quite short, stout, and progressively lengthening ; the proportions of the three
following are 7:9:5. Seta become prominent, but not numerous, on the fifth and sixth
joints ; on the preceding joints they are almost non-existent. The four terminal joints
are small, the proportions being about 4°5: 3: 2°5 : 2°75, the last one possessing a
curved terminal claw, quite as long as the joint, with half-a-dozen rather widely
separated teeth. All the terminal joints carry a few sete distally and dorsally. The
denticulate spines are not numerous, 5: 4:3: 4 respectively ; they consist of the normal
flattened blade with two prominent teeth on each side, and two others of which traces
remain. They are rather worn. (Plate X., fig 13.)

The Legs are rather short, about 16mm., very stout, but the tarsus and propodus
are very much reduced in diameter. Of the three coxze the second is much the longest,
but not so long as the other two together. The first is provided dorso-laterally with
two stout spines, and there is another rather smaller one laterally, on the posterior
side. A row of spinous sete occur laterally on the other two coxe. The distal
fringes of these two joints are ventral and inconspicuous ; that of the third coxa
is the best developed, and on this joint there are several small sete ventrally in
addition. The three following joints are subequal in size, the tarsus and propodus
together are three-quarters the length of the preceding joint, and are themselves sub-
equal. In these particulars this species is not in agreement with the preceding. On
the two tibize there are two dorsal rows of stout spinous sete, a lateral row on either
side, and a strongly developed ventral row. On the second tibia the distal fringe
is strongly developed ventrally, and spinous. The setze on the femur are smaller,
and only the two dorsal rows are distinct; the other three rows are present, but
very feebly developed; there is a prominent distal fringe dorsally. The tarsus and
propodus are similarly provided, but the setee are much smaller, The terminal claw

32 T. V. HODGSON.

is stout, not half the length of the joint that bears it, and provided with two small
auxiliaries.

The specimen described above is an adult female with Genital apertures on the
second coxee of all the legs. Nearly mature ova can be seen in the femora.

It was taken in Winter Quarters, in 125fm., 24 April, 1903. Bottom: small stones,
organic débris, polyzoa, shells, ete. Other specimens, generally smaller, were taken at
the same place on various dates, and also at other points three and nine miles away, and
at the same or greater depths, 180 fm. They all appear to be sexually mature, and
differ in a varying degree from the type in their spinose character. In all cases this
is more conspicuous in the males. The Genital apertures of the male are on the two
posterior pairs of legs only.

The numerous minor features which separate this species from the preceding
cannot, in my opinion, be ascribed to age. The form of the ocular tubercle readily
separates the two.

A specimen was taken in 125 fm. on 3 May, 1903, and is, I think, a young form
of this species. The differences between this specimen and the adult individuals are :—

The posterior articulation of the trunk is present, but very much less distinct than
the others.

Palps: the second joint is as long as the three following together. The third joint
is as long as the two terminals together, and of these the last is a little the longer.

Ovigers: these are quite rudimentary, small, and hook-like; no joints are
differentiated, though two are indicated.

Legs: the proportions of the joints differ somewhat and are, beginning with the
femur, 6: 7:7 : 2°25: 3°5. The limb is clothed with comparatively strong spinous sete
of some length, not very numerous, arranged in lines,

CHATONYMPHON AUSTRALE.
(Plate X., fig. 14.)

Nymphon australe, Hodgson (10), p. 25
Chatonymphon altioculatum, Mobius (23), p. 181.
Specific characters :—
Body robust, with lateral processes not widely separated but divergent ; entire animal rather
coarsely setose.
Ocular tubercle long and slender.
Palps five-jointed, proportions of last three as 7: 4°25: 4.
Oviger ten-jointed, denticulate spines fairly numerous, with four distinct lateral teeth on each side.
Legs short, tarsus a little longer than the propodus, the terminal claw with very minute auxiliaries.

Body robust, with stoutly developed lateral processes, which are distinctly though
not widely separated, the interval increasing with age; the body, exclusive of the
anterior part of the cephalon, forming an oval of graceful proportions.

The Cephalon is expanded, and the space between the chelifori is marked by a deep
groove, wide anteriorly. The neck is well defined, and behind this is the Ocular

PYCNOGONIDA. 33

tubercle, a structure which varies considerably in shape and size. As a rule it is rather
stout, and bears four well-developed eyes, with a variable amount of pigment. It is
slightly flattened antero-posteriorly, and more or less rounded at the extremity. The
cephalon and the lateral processes are provided with several long sete, the latter also
having a distal fringe.

The Abdomen is of moderate dimensions, pyriform, and rather thickly setose, not
separable from the trunk by an articulation.

The Proboscis is cylindrical, slightly enlarged about its middle. It is directed
downwards, and movably articulated to the trunk. No sete are apparent on its
surface.

The length of the entire body is 8mm. ; of the body only, 6mm. ; of the trunk, to
the insertion of the abdomen, 4°5mm._ Its width is 8mm.

The Chelifori are well developed ; the scape is a single joint longer than the
proboscis, liberally provided with long sete of irregular size, and also having a well-
marked distal fringe. The chele are slender, about as long as the scape. The palm
occupies half the length of the entire chela, and is covered with comparatively long
sete, which are continued far on to the immovable finger. The fingers are slender and
much incurved at the tips; they are provided with a large number of closely set teeth
of irregular length.

The Palps are slender and five-jointed. The first joint is quite small, the second
is the largest of all, and rather sparingly provided with setee, which are longest on
its outer side; the third joint is a little shorter, slightly enlarged distally, the sete
being more numerous and more uniform than on the preceding joint. Of the two
terminal joints the distal one is a little the shorter, but together they exceed the
length of the second by a trifle. These two joints are richly setose, particularly on
one side.

The Oviger is ten-jointed ; in the female the first three joints are very small, but
progressively increase in length. The fourth and fifth are subequal and much the
longer of the whole series, and slightly curved in opposite directions. The sixth joint
is about three-quarters the length of the fifth. Of the four terminal joints the first
three progressively shorten, the terminal one being a trifle longer than the preceding,
and it bears a long slender pectinate claw with eight teeth. The first four joimts bear
searcely any setee, except an inconspicuous distal fringe; on the fifth the sete are
noticeable on its outer border, and those of the distal fringe are rather long and
slender. In this particular the sixth joint is similar. The four terminal joints are
all provided with a distal fringe and a number of long sete. The denticulate spines
are arranged as usual in a single row, and, counting the joints from the base of the
appendage, they bear respectively 9: 7:5: 7 of these spines (Plate X, fig. 15). These
numbers are not, however, rigidly adhered to. The spines consist of flattened shafts of
a slightly sinuous form, bearing four well-developed teeth on each side, with traces of a
fifth in large and uninjured specimens. The third tooth from the base is usually the

FE

54 T. V. HODGSON.

largest. In the fully developed male the fifth and sixth joints are remarkably swollen.
The enlargement of the fifth joint affects the distal half. The eggs are large, and the
spherical masses may be two in number on each limb; they are carried round the
fourth joint.

The Leg extends to a length of 21mm. These appendages do not differ
appreciably in size. Of the three cox the second is much the longest, but not
so long as the other two together. The proportions of the three following joints are as
4:5:4°5. The tarsus and propodus together are as long as the femur, the former joint
being the longer of the two. The terminal claw is well developed, and is accompanied
by two very minute auxiliaries, not one, as stated in the ‘Southern Cross’ Collection,
Crustacea, p. 258. The entire limb is setose throughout, the sete abundant, and
variable in size, some of them distinctly spinous. For the most part their arrangement
is irregular, but on the second tibia a linear arrangement begins to be perceptible,
and this is clear on the tarsus and propodus, where the sete are much finer. The
distal fringe of the first coxa is dorsal, and not so strongly developed as on the
two following joints, more especially the third, where it is ventral. On the femur it is
chiefly dorsal, and the setae composing it are long and stout. On the first tibia
it is complete and rather spinous ventrally; this is more strongly developed on
the second tibia, where there is at least one powerful spine ventrally, and generally
two on each side. The male differs from the female in being more setose, the
setee being longer, more irregular, but scarcely, if any, stronger. The distal fringe
of the third coxa is particularly noticeable for the great length of the sete
composing it.

The Genital apertures of the female are conspicuous on the second coxa of all the
legs; those of the male are much smaller, and can only be detected on the two
posterior legs.

This species was taken in considerable numbers off Cape Adare, but inside
Robertson Bay, in 20-26 fm. None were taken by the ‘ Discovery.’ I have re-
described it here to remove certain defects of the original description, and on account
of the capture of a form which, after considerable hesitation, I feel compelled to regard
as only a variety. This species is closely allied to N. brevicaudatum Miers, with which
N. horridum Bohm has been identified by subsequent investigators. NV. brevicaudatum
Miers, can be readily distinguished from NV. australe by the following characters :—

The trunk is more setose,

The tarsus is shorter than the propodus.

The terminal claw has two distinct, if small, auxiliaries.

The oviger bears a very much smaller series of denticulate spines, but their lateral

teeth are more numerous.

Iam unable to regard the Chetonymphon altioculatum of Mobius as a distinct
species, several examples of which were taken in the vicinity of Bouvet Island during
the ‘ Valdivia’ expedition.

PYCNOGONIDA. 35

CH&TONYMPHON AUSTRALE, va’. AUSTRINORUM,
(Plate IV., fig. 4; Plate X., fig. 15.)

Although no specimens of Chzxtonymphon australe were taken by the ‘ Discovery,’
yet a large number of individuals of a closely allied species were taken in Winter
Quarters, chiefly at the beginning of our stay there, before the ship was frozen in, and
while dredging was still possible within the 20-fathom line.

At first sight these specimens seem to be a distinct species; they are half as large
again or more, and their setose covering is finer. The intervals between the lateral
processes are much greater, and this is the only character of importance that separates
them. Another feature of doubtful value lies in the fact that the tarsus and propodus
together are distinctly shorter than the femur. In C. australe these two joints are as
long as the femur, or very little shorter, but the slight variation that occurs prevents
the acceptance of this fact as a reliable specific character.

The setose covering has already been alluded to as finer; it is so, but subject to
considerable variation both as to quality and quantity. In average specimens there are
large spinous setz on the tibiz, especially on the second. These are, for the most
part, arranged in a line but not very distinctly. Two dorsal rows, and a lateral row
each side can be distinguished, these are most prominent on the second tibia. There
may also be a mid-ventral row of very small spinous sete, rather closely set. Both
in C. australe and the specimens from Winter Quarters the ventral setz of the
femora and the two tibiz are much less conspicuous than elsewhere. In many indi-
viduals there is a conspicuous mid-ventral row of sete: on the tarsus; these are closely
set and about as long as the diameter of the joint.

Two specimens were taken in 100fm. off Coulman Island ; of these one is com-
paratively small. The Ocular tubercle is rather more conspicuously flattened and very
slightly constricted below the eyes. The sete are as in the Winter Quarters
specimens, but without the spinous rows which, as before noted, are not always obvious.
Two other specimens were taken off the Barrier in 300fm. Lat. 78° 25’ 40” 8,
long. 185° 39’ 6” E. These are both males, one with young. In these the Ocular
tubercle is flattened, as in the Coulman Island specimens, and the terminal claw of the
lee is rather longer and more slender. The setose covering of the legs is very much
finer, but its arrangement is exactly the same.

It is quite impossible to find a distinct character by which these specimens can be
separated from C. australe, therefore I feel compelled to regard them as a variety only,
and a more southern form of that species. Some comparative measurements are given
below.

C. australe. C. australe, var. austrinorum.
Wii): Coulman, Barrier.
Length of entire body . : : . 8mm. 11 Ye 2 12
Length of body . ; . . . 6mm. 8 55 95 Sa
Length of trunk, to insertion of abdomen 4°5mm. 6 4 7 7

Length of abdomen

Width of trunk . : 5 :
Length of thirdleg . : ;
Proportions of femur and two tibize

T. V. HODGSON.

C. australe,

1°5mm. 2
3mm. 4
21mm. 31
4 5 45 6

As long as femur,

C. australe, var. austrinorum.

W. Q. Coulman. Barrier.
15 25 2°5
3 scarcely 5 scarcely 5
18 32 37

Ceti tf SY

45 «4

Shorter than femur

Tarsus and propodus together
or very nearly.

In all cases the tarsus is longer than the propodus.

The Palps are alike in all cases, but these have not been accurately measured, as
this cannot be done without removal.

Fig. 4a is that of a Winter Quarters specimen.

The Ovigers are essentially alike, the differences between one or two of the joints
being very trivial (fig. 4b). The number of denticulate spines is too irregular to be of
any value.

paee hee 4 potas Vic a Say hee ae tes Cons Fee Ok

The character of these spines is Shown in Plate X., fig. 15.

The sexual difference in these organs is the same in all, and the ova, which are
known in all but the Barrier specimens, are large and attached to the oviger in precisely

the same way.

PENTANYMPHON.

Body smooth, very slender, with lateral processes widely separated. Five pairs
of legs. Chelifori well developed, chelate ; scape a single joint. alps five-jointed.

Ovigers ten-jointed, terminating in a pectinate claw, the last four joints with
a single row of denticulate spines.

But for the additional pair of legs it would be quite impossible to separate
Only a single species is for the present recognised,
It has been taken by the

this genus from Nymphon.
and this appears to have a cireumpolar distribution.
Scotch, German, and French Expeditions.

PENTANYMPHON ANTARCTICUM.
(Plate V.)

Pentanymphon antarcticum, Hodgson (11), p. 458; Cole (7), p. 405; Bouvier (3), p. 294.
Specific characters :—
Body very slender, lateral processes long and widely separated, neck very long.
Chelifori : chelz: long and slender, shorter than scape, with short, stout, uniform, close-set teeth.
Palps : terminal joint longer than preceding, which is in turn half the length of the third.
Ovigers : terminal claw pectinate, denticulate spines, with seven pairs of lateral teeth, the first
being very small.
Legs rather long and slender, with a well-developed terminal claw and two auxiliaries ; sete
arranged in four rows on the last three joints.

PYCNOGONIDA. 37

The body is very slender, quite smooth, with very widely separated long lateral
processes. Anteriorly it is slightly curved downwards.

The Cephalon is long and slender, longer than the second and third segments, and
expanded distally into two dorsal lobes for the articulation of the chelifori.

The Ocular tubercle lies immediately in front of the first pair of lateral processes.
It is short, merely a low rounded hump, in fact, bearing four well-developed eyes.

The Abdomen is very small, directed upwards, and not separated from the trunk
by an articulation. It is rather conical and extends but little beyond the trunk, not
nearly so far as the posterior lateral processes.

The segmentation of the trunk is distinct, the joints occurring immediately behind
the lateral processes.

The Proboscis is directed downwards, cylindrical, with a slight swelling about
the middle of its length; it is as long as the cephalon, and its extremity is rounded.

The Chelifori arise above the proboscis, each on a lobe of the cephalon, which is
here rather more than twice its diameter posteriorly. The scape is single-jointed,
longer than either the proboscis or the chela. A few delicate setze are scattered along
its length, and there is an inconspicuous distal fringe. The chela is a little shorter,
the palm and dactyli occupying equal halves; the former is covered with fine sete
which also form a fringe round the base of the movable finger. The fingers are slender
and much curved near the tips. Both are provided with a row of fairly stout teeth of
nearly uniform size, rather closely set.

The Palps arise below the chelifori and at the sides of the proboscis ; they are
built on exactly the same plan as in the genus Nymphon (fig. 1a). The first joint
is small and stout, the proportions of the remainder being 8:5:3:4. The second
joint is sparingly setose except for a distal fringe; the other joints become more
and more setose to the last, which is richly supplied. On the outer side they are more
abundant than elsewhere.

The Ovigers are ten-jointed and present in both sexes. (Fig. 1b.) They arise
from very short but conspicuous processes on the lower side of the cephalon,
immediately in front of the first pair of lateral processes. The details of this
appendage are as in Nymphon. The first joint is very small, the second is twice the
size, and the third, which has a very oblique termination, is a little longer still ; none
of these bear sete. The fourth joint is very long, slender, and slightly curved ; it
carries a glandular aperture on its outer side about a quarter of its length; all the
setee are small; very few occur except as a distal fringe. The fifth joint is longer still,
the longest of the appendage, and its distal half is enlarged in diameter ; it is covered
throughout with fine sete. The sixth joint is rather more than half the length of
the fifth, slightly curved, and on the outer side of the curve plentifully supplied
with fine sete. Of the four terminal joints the first is little more than half the
length of the preceding, the other three are shorter and sub-equal; very few sete
occur, except distally. They carry a single row of denticulate spines (fig. 1c). These

38 T. V. HODGSON.

spines consist of a slender shaft with a swollen base; near the base is a pair of
small teeth followed by two pairs of comparatively long slender ones ; the remaining
four pairs are more slender and blade-like, graduating to a mere trace. The terminal
claw is furnished with about nine slender teeth. Both denticulate spines and
terminal claw are frequently very much worn.

With regard to the Legs, all five are practically of the same size and proportions,
and though there is a considerable amount of variation in this respect it is confined to
narrow limits. They may attain a length of as much as 36mm. Of the three cox, the
first and third are sub-equal and together about as long as the second ; all, especially
the third, bear a few minute sete, chiefly ventral. The proportions of the three
following joints are approximately as 6°5:7 and 10; the tarsus and propodus are long
and slender, the former being the longer. The limb is more or less covered with fine
sete. On the femur they are scanty and for the most part small; a few longer ones
are to be found along the shaft and distally. On the first tibia they are comparatively
long and arranged in four indistinct rows, of which the lateral ones are not easy
to observe. On the second tibia they become smaller and much more numerous,
especially distally, and the distal fringe is strongly developed ventrally. The same
arrangement holds good for the two remaining joints, but the ventral row is very
strongly developed, the sete becoming almost spinous and closely set. The terminal
claw is a powerful one, and is accompanied by two slender auxiliaries of about quarter
its size.

The Genital apertures of the female are found on the second coxe of all the legs,
and in the adult they are distinct enough. The apertures of the male are at all times
difticult to observe, and I have only been able to distinguish them on the three posterior
pairs of legs.

Nearly thirty specimens of this species were taken in Winter Quarters, at all times
of the year, and in depths ranging from 12 to 125 fathoms. They vary considerably
in size, a Variation obviously due to age, but in essential details they are in agreement
except in one particular, and that is the articulation of the abdomen to the trunk; in
certain cases among the more robust forms it is distinctly articulated. The trunk in
all cases is seen to be very minutely scabrous when removed from spirit. The females
are more robust than the males when the sexes can be separated, a feature which is
most noticeable in the femora, but extends to the first tibia. The males, as a rule, are
rather more setose than the females.

A few of the eggs borne by one of the males are hatched. On emerging from the
ege the body is ovoid, and possesses three pairs of appendages. The cheliforus
comprises a stout scape with one very long seta, and a small but well-developed chela,
without teeth on the dactyli; a small proboscis lies below these. Details of the other
two pairs of appendages cannot be seen without special preparation, which has not as
yet been undertaken. Other specimens crawling about the egg-masses show the
proboscis, chelifori, the palps not clearly jointed, and four pairs of appendages, having

PYCNOGONIDA. 39

three stout sub-equal joints, followed by a fourth nearly as long as the three together,
only a great deal more slender, and terminating in a very minute claw; a conical
abdomen lies at the extremity of the trunk, the posterior part of which is provided
with a small number of very long sete.

LEIONYMPHON.

Prof. Mébius (23) has described this genus as follows :—

“Koérper kurzhaarig. Rumpf breit. Beintriger am Grunde zusammenstossend. Hals kurz und
breit. Augenhiigel konisch mit 4 Augen. Riissel walzenformig. Finger ohne Ziihne. Palpen

neungliedrig. Brutbeine zehngliedrig, 7. Glied beim Miinnchen kurz und dick ; alle Glieder nur kurz
behaart.”

LEIONYMPHON, 7.9.*

Rumpf ebenso breit wie lang. Die beintragenden Seitenforsitze der Rumpfglieder stossen
zusammen. Kopfsegment breit. Augentriiger konisch.

Riissel walzenformig. Scheren kurzer als der Riissel. Finger ohne Zine. Palpen neungliedrig.

Brutbeine zehngliedrig ohne eigentiimlich geformte Dornen oder Ziihne an den 4 letzen Gliedern.
An den minnlichen Brutbeinen ist das 7. Glied sehr kurz, aber viel dicker als die andern 3 Endglieder.

This genus was established for the reception of a remarkably fine species, L.
striatum (Mobius), of which however only two examples were taken, and both of them
immature. A species in the same collection described by Prof. Mébius as Colossendeis
gibbosa appeared to me to be closely related, and an examination of the two species
which I have been permitted to make fully confirmed this suspicion. The ‘ Discovery ’
has brought from the Antarctic several species which are unquestionably very closely
related. The ‘ Francais’ (2) has also found two species. Two more were described
some years ago by Dr. Pfeffer (24), from South Georgia, and placed by him in the genus
Ammothea,

That the genus Leionymphon is very closely related to Amimothea is beyond all
question. To this latter genus not less than thirty species have been ascribed, but
many of them present such peculiar characters that they cannot fairly be included. It
is not possible here to revise the genus, but I have considered it desirable to modify
Prof. Mobius’ definition of the genus Leionymphon, and to give a list of those species
which I consider should be included therein.

LEIONYMPHON.

Body more or less robust, with transverse ridges developed to a greater or less extent. The
lateral processes widely separated or otherwise ; spurs rather than spines, or traces of them, occur on
the lateral processes and first coxee.

The Proboscis is large, cylindrical or pyriform.

The Palps are nine-jointed, the last five joints being short.

* “delos glatt. Die 4 letzten Glieder der Brutbeine sind nicht mit eigentiimlich geformten Zihnen oder
Dornen besetzt.”

40 T. V. HODGSON.

The Oviger is ten-jointed, without a terminal claw, the last four joints with an irregular series of
special spines. In the male, the seventh joint bears a tuft of sete, and the eighth and ninth joints are
articulated at a considerable angle to the preceding joints.

The Legs are long, tarsus very small, propodus armed proximally on the ventral margin with a
series of stout spines, claw rather large, and accompanied by two well-developed auxiliaries.

The Genital apertures occur in the male on the two posterior pairs of legs; in the female on
all the legs.

The species I would assign to this genus are :—

L. striatum, Mobius, 1902.

L. grande, Pfeffer, 1889 = Ammothea yrandis, Pfeffer.
= Ammothea charcoti, Bouvier.

L. gibbosum, Mobius, 1902 = Colossendeis gibbosa, Mobius.

L. minus, sp. noy.

L. clausii, Pfeffer, 1889 = Ammothea clausii, Pfeffer.

LL australe, sp. nov.

L. ylaciale, sp. nov.

LL, spinosum, sp. nov.

I have hesitated for some time as to the position of Ammothea magniceps (Thomson)
from New Zealand (30). Mr. G. M. Thomson most kindly placed the whole of his
collection at my disposal, but unfortunately it does not contain an adult male of this
species, therefore the structure of the male oviger remains unknown. The transverse
ridges of the trunk are prominent, but there is no trace whatever of the spurs so
characteristic of Leionymphon. Under any circumstances, the species cannot be
regarded as a true Ammothea. (Mr. Thomson is in error in describing the palp as
with ten joints, there are only nine.) Be the true position of this species as it may, it
exhibits a preliminary stage in the transition between the diminutive Ammothea and
the large Leionymphon. The next step is indicated by LZ. elausii and L. australe ;
these two species are very much alike; from these by L. minor, L. gibbosum, and
L. grandis to L. striatum. It would be difticult to give L. glacialis and L. spinosum a
position in a linear series. They probably diverge from L. striatum in a different
direction to the others.

KEY TO THE SPECIES.

Body traversed by three prominent pyramidal ridges, spinose or setose :—
Lateral processes close together—
*Proboscis half as long as body, cylindrical. LZ. striatwn.
Proboscis little longer than body, cylindrical. LZ. grande.
*Proboscis as long as body, conical. L. gibbosum.
Proboscis shorter than body, slender, pyriform. ZL. minus.
Lateral processes widely separated —
Proboscis little shorter than body. ZL. glaciale.
Proboscis short, not half length of body. L. spinoswm.
Body traversed by three rounded ridges, smooth :—
Abdomen vertical, base traversed by the last trunk articulation. JL. clausi.
Abdomen oblique, some distance behind the last trunk articulation. L. australe.

* Known only from immature examples.

PYCNOGONIDA. 41

LEIONYMPHON GRANDE.

(Plate VI., fig. 1.)

Ammothea grandis, Pfeffer (24), p. 48.
Ammothea charcoti, Bouvier (2), p. 295.

Specific characters :—
Body robust, with three prominent transverse ridges dorsally and ventrally.
Proboscis cylindrical, very little longer than the body.
Palp 9-jointed, the last joint a little longer than any of the four preceding ones.
Oviger 10-jointed, without a terminal claw, the last four joints with simple curved spines, which
increase in size to the extremity of the last joint.

The body is stout, and with the abdomen, scarcely as long as the proboscis,
being just less than 15mm. Its width across the second pair of lateral processes is
10mm. Its segmentation is complete, but concealed by a very strongly developed
pyramidal ridge which lies along the posterior margin of the three anterior segments,
and the apex of which is raised considerably above the body level. These ridges have
a very slight curvature forwards, which is most marked in the first. The lateral
processes are not widely separated, the two anterior pairs are directed forwards, the
first more than the other, and are quite close together; the third pair is directed
backwards slightly with a wider interval between it and the preceding pair; the last
pair is directed backwards at such an angle as to make the interval between the third
and fourth pair very conspicuous. All have a swelling at the distal extremity, and
this swelling gives the process an angular appearance.

The Cephalon is short, expanded anteriorly, and at the base of the chelifori presents
the same angular appearance as the lateral processes. A slight median groove divides
its anterior margin.

The Ocular tubercle lies in the middle ; it is stout, with a very slight curvature,
rounded at the apex, and bearing four well-developed eyes.

The Abdomen rises from the extremity of the trunk, but without trace of
segmentation ; it is rather stout, slightly curved, and directed upwards. There is a
median tubercle between the posterior transverse ridge and the abdomen. Dorsally
the entire body is rendered scabrous by the presence of small spinous sete; between
the body ridges however they are scarce. Ventrally the three transverse ridges of the
dorsum are represented by three similar ridges, thimner and not produced to such a
conspicuous point; all are directed backwards to a varying degree, the first more so
than the others. These ridges are continued on to the base of the lateral processes,
which here do not present any trace of the angular enlargements so conspicuous
dorsally. The spinous sete of the dorsum are not present.

The Proboscis is stout and cylindrical, only a trifle longer than the body and
abdomen together. It is articulated to the body, and movable through a very
considerable angle. The mouth is large and triangular. The distal extremity of the
organ is deeply pigmented; for nearly three-quarters of its length it displays six

G

42 T. V. HODGSON.

bands of a dark yellowish-brown colour ; it then abruptly changes colour, and tapers
a little to its junction with the body.

The Chelifori are rudimentary, and arise from the cephalon dorsal to the proboscis,
and rather in advance of its origin. The scape is short and stout, slightly curved, and
with the distal extremity oblique. Articulated to it is a mere knob which bears at its
extremity a minute tubercle in a distinct socket, and on its outer border a small
spine. The entire appendage is covered with minute spinous sete.

The Palps are nine-jointed, and arise from the cephalon immediately below and
external to the chelifori. The first joint is small, and the second is very nearly four
times as long, the third is again small, and the fourth nearly twice as long as the
second. The remaining five joints are together but little longer than the fourth,
and. differ but little in size; the terminal one, however, is the longest of this series.
The entire appendage is covered rather irregularly with the characteristic small
spinous sete of the animal. They are not numerous on the proximal four joints,
hut on the remaining five they are rather longer and finer, as well as being a little
more abundant.

The Ovigers are ten-jointed, and arise ventrally at the angles formed by the first
pair of lateral processes and the body. All the joints are small, the second and
fourth being a little the longest (fig. la). The first joint is very small but stout, the
second and fourth are the longest and sub-equal, the third is shorter and slightly
eurved. From the fourth the three following joints progressively decrease a little in
length, the first three forming a curve in the natural position of the appendage. All
these joints are stout, the three terminal ones becoming more and more slender; the
eighth joint, though more slender, has the same character as the preceding, the ninth
is a little shorter, and the last one is the longest of the four terminals. The entire
limb is covered, but not thickly, with small sete ; they are most numerous on the
fourth, fifth, and sixth joints, on the latter of which they are conspicuous only on the
outer side of its curvature. The remaining four joints form a curve in a contrary
direction, and on the inner side of this curve is a row of stout curved setz, increasing
in size and strength to the end of the terminal joint, where they form a conspicuous
croup. These spines are quite simple, and the last joint does not bear a claw, though
it seems adapted for one.

The Legs are stout but not of any excessive length, being something like 62mm.
The second coxa is fully as long as the other two together, and the proportions of the
remaining joints are as—15:13:17:1:5. The first coxa is marked with a median
dorsal and ventral line which separates the muscles moving the succeeding joint, the
distal margin is tuberculated dorsally like the lateral processes, but only to a very
slight extent; the second coxa is conspicuously wider in diameter at its distal than at
its proximal extremity. All three are covered with very small but stout sete. The
femur is a stout joint, its distal extremity being raised dorsally into a slight angular
ridge ; the entire joint is covered with the characteristic sete with the exception of a

PYCNOGONIDA. 43

lateral band of some width, almost completely bare of them. On the two tibize the
same arrangement of the setee occurs, except that along the middle of the bare band
there is a narrow band of setee two or three wide. The distal fringes of the femur and
first tibia are not conspicuous, but that of the second tibia is formed of stout spines
chiefly on the ventral surface. The tarsus is a very small joint, and forms a cup-like
socket for the propodus (fig. 1b); it is thickly covered with small spines, and its distal
fringe is well developed, especially ventrally, where it is formed of very stout spines.
The propodus is covered thickly with stout setee with only an irregular vestige of the
bare band found on other joints; it is slightly curved, and its ventral side bears
proximally four or more very stout spines, of which the first is the smallest; the rest
of the margin is taken up with set small, but larger than the average ; close to the
terminal claw is a group of large sete, one of which at least is a rather prominent
spine. The extremity of the joint is oblique, and forms a rounded spinose projection
or heel beyond the origin of the stout claw, which, with its two powerful auxiliaries,
arise from a common investment.

The single adult specimen captured is a female, and the Genital apertures are
conspicuous on the second coxa of each leg. Five smaller specimens were, however,
taken at the same time and place, varying in size from 9°5 mm, to 18°5 mm. over all.
These present several differences of no small importance. The proboscis differs shghtly
in form, being more tapering the smaller the specimen, and it is also more rigidly
articulated to the body ; in none of them is it movable through so large an angle as
in the adult. The chelifori are proportionally the same size as in the ‘adult, but a
perfect chela is developed. This is small and feeble, the fingers curved like a pair
of callipers, and devoid of teeth. On the body the dorsal ridges are raised into a
more definite median point, and the tubercles which give an angular appearance to the
lateral processes and first coxee of the adult are now rather more prominent and carried
on to other joints. The pre-abdominal tubercle is a very variable structure, and is
sometimes prominent—in one case almost absent. The palps do not call for any fresh
description, but the ovigers show several interesting stages in their development (figs.
1c-1f). In the smallest specimen only the merest vestige of such an appendage exists.
In the next specimen four joints as such may be distinguished, the last one showing an
indication of future segmentation. In another, six joints are fairly well established,
the penultimate one showing traces of another division. In the largest of the
immature specimens the oviger possesses the full number of ten joints, but they are
very small, and the four terminal ones are only indicated and not clearly developed.

Cape Wadworth, Coulman Island, 8-15 fathoms. Bottom: stones. Several
adult specimens were taken by the ‘Frangais’ off the west coast of Graham’s Land,
and one was taken by the ‘ Scotia.’ The examination of Professor Pfeffer’s Ammotheu
grandis from South Georgia has established the identity of this species beyond all
question.

G 2

44 T. VY. HODGSON.

LEIONYMPHON MINUS.

(Plate VI., fig. 2.)
Specific characters :—

ody rather robust, with three prominent transverse ridges produced to a point in the mid-
dorsal line.

Proboscis shorter than the body, slender, pyriform.

Palp 9-jointed ; the terminal joint twice as long as any of the preceding four.

Oviger 10-jointed. In the male the three terminal joints bear an irregular series of stout but
simple spines. No terminal claws.

The body is rather robust and the lateral processes are clearly but not very widely
separated. It measures rather less than 5 mm. in length and less than 4 mm. in
extreme width. The segmentation is distinct, and the articulations lie at the hinder
part of the three transverse ridges which cross the body. These ridges are strongly
developed, produced to a point in the middle line, and slightly curved backwards. They
are equally prominent ventrally, but inflected backwards and not produced into a
point. The lateral processes are stout, the two anterior being directed forwards at
slightly different angles, the two posterior ones are similarly directed backwards ; each
bears dorsally two distinct tubercular processes which are also to be found in a less
prominent degree on the first coxe.

The Cephalon is scarcely, if at all, expanded, and its centre is occupied by a very
stout Ocular tubercle which is directed slightly forwards, and appearing, in certain
aspects, to be enlarged near its extremity, which bears a very rudimentary spine. The
four eyes are not particularly well developed.

The Abdomen is short and stout, not separated from the trunk by an articulation ;
it is directed obliquely upwards and does not extend as far backwards as the last pair
of lateral processes.

The Proboscis is pyriform, slender, and about two-thirds the length of the body,
to which it is flexibly united. It shows indistinctly three pairs of longitudinal bands
along the greater part of its length.

The Chelifori are rudimentary ; the scape is well developed, slightly curved, and
bears only a few small setze besides the rather prominent distal fringe. The chele are
reduced to a knob with the merest traces of fingers.

The Palps are 9-jointed and rise at the side of the proboscis; the first and third
joints are quite short and subequal, the second and fourth are also subequal and about
five times as long; the four following are quite short and subequal, while the terminal
one is ovoid and twice as long as any of the preceding four. The fourth joint bears a
small distal fringe, but otherwise there are practically no sete on the first four joints ;
the following four joints are very considerably dilated ventrally, and this enlargement
bears a dense tuft of small stiff sete. The terminal joint is more extensively covered
with sete, especially on its ventral side.

The Ovigers are 10-jointed and rise ventrally just in front of the first lateral

PYCNOGONIDA. 45

process (fig. 2a). The first joint is small and stout, the second is more than twice
as long, stout and enlarged distally, the third is scarcely as long and has an oblique
termination. These three joints form a curve in one direction, and the three following
form a similar curve in another. The fourth and fifth joints are long and subequal,
the sixth being about half the length of either; its termination is rounded, the
following joint being articulated at the side. All these joints are more or less
plentifully setose; the sete are very small, but their structure and arrangement call
for no comment. The seventh and succeeding joints progressively decrease in length
and stoutness as far as can be made out from the angle at which they lie, and they
are all small. The seventh lies at right angles to the sixth, and near its distal and
inner side it bears a dense tuft of long sete. The eighth joint is articulated at
the side of the seventh and at right angles to it; it also bears a small tuft of long
sete near its distal extremity but on its outer side; the following joint is similarly
provided, but with fewer. The last three joints bear an irregular series, not a single
row, of stout spines (fig. 2c); most of them occur on the terminal joint, but there are
scarcely a dozen altogether. There is no terminal claw.

The Oviger of the female is essentially different to this (fig. 2b). All the joints
are smaller, the third conspicuously smaller than the preceding, and the fourth, though
the longest of the appendage, is still quite short, and the remainder gradually and
progressively decrease in length. Up to the sixth the joints remain stout, the rest are
much more slender, and there is nothing noteworthy in their articulation, which is
quite normal. The sixth joint is thickly covered on its outer side with minute sete,
and up to this joint the sete have been increasing in number. The terminal joint is
unfortunately missing in the specimen examined, but the three preceding are almost
devoid of any sete at all.

The Legs measure about 28 mm. in length. The second coxa is searcely the length
of the other two together, the femur measures some 7 mm., the first tibia is the merest
trifle shorter, the second a little longer, 7°5 mm., the tarsus and propodus together are
about one-third the length of the second tibia. The second coxa bears a small but
distinct tubercular enlargement just beyond the middle of its length dorsally, and in
the male there is a similar tubercle dorsally near the extremity of the femur, with
a glandular aperture upon it. The entire limb is setose, but the sets are very small ;
no definite arrangement can be seen as far as the first tibia, up to this joint they are
not numerous and only visible with difficulty. On the tibiee they become numerous; on
the first their arrangement is indistinct, on the second it is more readily made out, and
consists of a dorsal and a ventral band of sete: with another narrow band passing along
the centre of a bare space laterally. The distal fringes are but poorly developed, the
most conspicuous one being on the second tibia and chiefly ventral. The tarsus is a
very small cuplike joint, densely setose on its longer and ventral margin. The propodus
is slightly curved and dorsally projects considerably beyond the insertion of the large
terminal claw and its strong auxiliaries. The joint is thickly covered with stout

46 T. V. HODGSON.

setee on its ventral surface, and proximally there is a row of some four to six very
strong spines; dorsally the sete are similar, but not so thickly distributed nor so
strong; laterally also they occur, and there appears to be a narrow band devoid of
sete, but this is not distinct. The terminal claw and its auxiliaries arise from a process
on the ventral side of the prolongation alluded to above.

The type of this species is an adult male bearing eggs, taken in Winter Quarters at
a depth of 125 fm., 9 Feb., 1903. Another was found at a depth of 35 fm., 5 March,
1903. The ova are small and are carried in a large, rather irregular mass round the
fourth and fifth joints of the oviger. The Genital apertures occur ventrally at the distal
extremity of the second coxa of the two posterior legs. They are large, with tumid
lips. Genital apertures of the female are on all the legs. A male and a female were
also taken off Cape Wadworth, Coulman Island, in 8-15 fm., 15 Jan., 1902. These
are smaller than the type.

LEIONYMPHON AUSTRALE.

(Plate VII., fig. 1.)
Specific characters :-—
3ody robust, with three low rounded transverse ridges; these ridges are more prominent
ventrally. Abdomen directed obliquely upwards, and well behind posterior trunk articulation.
Proboscis pyriform, little shorter than the body.
Palp 9-jointed, the seventh and ninth being a little the longest of the five terminal joints.
paed - : J]
Oviger 10-jointed, without a terminal claw, the last four joints with an irregular series of
g J J g

denticulate spines.

The body is robust and, without taking the lateral processes into consideration,
broadest about the third process, from which it gradually narrows forwards.

The Cephalon is but slightly expanded and the neck is not distinct. The entire
body measures 9 mm. in length, of which 4 mm. are taken up by the proboscis ; the
Abdomen does not enter into consideration, as in its natural position it is carried
obliquely upwards, and does not extend beyond the last pair of lateral processes ; it
is, however, 1§ mm. long. Segmentation is distinct, except so far as regards the
abdomen, and occurs on a low ridge which crosses the body immediately behind the
lateral processes. These ridges also occur ventrally and, being reflected backwards,
give to each segment the appearance of being socketed into a recess. The lateral
processes are not widely separated, but the intervals increase slightly from before,
backwards ; all are provided at their distal extremities with two small spur-like
processes ; these are dorsal.

The Ocular tubercle is stout, moderately tall, rounded at the apex, and bears four
well-developed eyes.

The Proboscis is movably articulated to the body and pyriform in shape, its
diameter increases for more than a third of its length, and then enlarges abruptly,
and is marked by three double bands, presumably muscle bands, transversely divided
near the tip. The mouth is triangular, not large, but with thick lips.

PYCNOGONIDA. 47

The Chelifori are rudimentary and comprise a stout scape of one joint, which
is slightly curved; except for a distal fringe which is not conspicuous, the joint
is not setose. The chele in the adult are only represented by knobs, and these
show the merest traces of two fingers. In younger specimens the chelee are developed
and exhibit comparatively long curved fingers devoid of teeth.

The Palps are nine-jointed and arise at the side of the proboscis. The first joint
is short and stout, the proportions of the three following are as 5 : 1 : 4; the remaining
five are all short and differ little in size, the first and third are sub-equal, the
second and terminal are very little shorter but also sub-equal, the penultimate is the
shortest; the last joint is ovoid in shape, setose throughout, the setae more thickly
distributed on its inner margin. The other four joints have slender bases and are
much enlarged and densely setose on the inner margin; the outer margin is straight
and bears a distal fringe. The preceding joints are also more or less setose, the short
setee beginning near the distal extremity of the second joint and becoming fairly
numerous on the fourth.

The Ovigers are ten-jointed and arise ventro-laterally immediately in front
of the first pair of lateral processes; they differ in the two sexes. In the male
(fig. la), the first joint is small and stout, and the proportions of the five following
are as 4:2°3:4:4:2; the first of these, second of the appendage, is slightly
curved; the next is less so, but with the three following forms a large curve,
the fifth joint being the only one that is distinctly curved itself. All these
joints are setose, particularly on the outer side of the curvatures. The four
remaining joints are short; the seventh is articulated at the end of the sixth, but
at the side, and makes nearly a right angle with it; near its distal extremity
it is provided with a dense tuft of long seta. The eighth joint is similarly
articulated to the seventh, but in the opposite direction, and bears a smaller
tuft of long sete distally; the ninth is the shortest joint. The three terminal
joints bear a small number, less than a dozen, of denticulate spines, most of
which occur on the terminal joint. They are not in a single row, and consist
of a slender shaft with seven closely-set flat teeth on each side.

The oviger of the female is quite different and the articulation of its joints
is normal throughout (fig. 1b). The first and third joints are together equal to
the second; the fourth and fifth are sub-equal, and the longest on the appendage ;
the sixth and seventh are a little shorter and sub-equal, the eighth and tenth
are again shorter and sub-equal, and the ninth still shorter. Sete are scarce,
and the sixth joint is the only one that can be described as setose. The
denticulate spines occur on the four terminal joints, and are exactly like those
of the male, but much more numerous, there being upwards of a dozen on
each of the joints except the first of the series.

With regard to the Legs, the second coxa is scarcely as long as the other
two together; the proportions of the three following joints are as 6°5:6:7°5;

48 T. V. HODGSON.

these joints are subject to variation, but not of great moment, ‘5 mm. or there-
abouts; the tarsus is quite small and cup-shaped, the propodus rather more
than a quarter the length of the second tibia. The entire limb is covered with
short sete, but on the second tibia and the propodus there are longer ones
interspersed among them. Throughout the entire limb there is a broad lateral band
devoid of setee except for a narrow row of them along its centre; dorsally and ventrally
the sete are abundant, particularly towards the extremity of the limb. The distal
fringes are normal and inconspicuous, @.¢., indistinct on the first coxa, ventral or
chiefly so on the other two, complete on the femur; on the two tibise they are
best developed ventrally, and become spinous, especially on the second; the tarsus
is covered with small spines or spinous sete ventrally, the propodus has a very
prominent heel and bears a stout claw with two well-developed auxiliaries
rather more than half its size. The heel bears numerous spinous sete, and at
the proximal end of the joint on its ventral margin there are some half-dozen
stout and prominent spines.

The Genital apertures occur on the second coxz of all the legs in the
female, but they can only be found on the two posterior legs of the male.
The ova are small and numerous and are carried in a spherical packet round
the fourth joint of the oviger.

Several specimens of this species were taken in Winter Quarters at depths
varying from 25 to 125 fms., the majority however coming from the latter
depth. The specimens vary in age and size, but the species may be regarded
as a variable one. While the general arrangement of the setee remains the same
it is not so clear in the young examples. In these the sete are for the most
part long and fine instead of short and comparatively stout; the transition
from the one form to the other is gradual, some of the adults retain a goodly
proportion of the long sete among the others. A very few minute sete may
be found on the body in some individuals, especially on the abdomen. In most
individuals the summit of the ocular tubercle bears a very short spine instead
of being rounded. In the young the chele are fairly well developed, they are
of moderate size, the fingers being quite smooth and resembling a pair of callipers.
The spurlike tubercles on the lateral processes of the adult are, in the young,
very prominent spines and frequently bifurcated ; similar spines occur on the cephalon.
One specimen has the oviger not completely developed and in another the full
number of joints is not yet differentiated.

All the adults possess a glandular aperture of some kind on the dorsal
surface of the second coxa just beyond the middle of its length.

One individual has the second and third legs of the left side abnormally
developed, probably new growths in reparation of injury; one of these limbs
does not extend beyond the extremity of the first tibia, the other is longer.

This species very closely resembles L. clausi Pfeffer, but may be readily

PYCNOGONIDA. 49

distinguished by the fact that in that species the abdomen is directed almost
vertically upwards, and is situated so far forward that the posterior trunk segment
passes over its base, a feature of, possibly, some morphological importance.

LEIONYMPHON SPINOSUM.
(Plate VIL, fig. 2.)

Specific characters :—

Body stoutly built, with the transverse ridges not very strongly developed, but with a very
prominent spur in the mid-dorsal line. The lateral processes are rather widely separated, and bear
distally two stout recurved spurs ; smaller ones exist on the first coxa,

Proboscis short, not half the length of the trunk. bs

Palps 9-jointed ; of the five terminals the seventh and ninth are a little longer than tke others.

Oviger 10-jointed, special spines not denticulate.

The entire animal is heavily built, and covered with fine but short sete. The
lateral processes are rather widely separated, the intervals increasing posteriorly, two
pairs of processes are directed more or less forward, the other two pairs backward.
Each process bears dorsally at its distal extremity a pair of prominent recurved
tubercular processes ; these are also distinct, though less prominent, on the first coxe.
The body is crossed transversely by three ridges, but these do not extend on to the
lateral processes as much as in the allied species. These ridges stand erect, but they
are bevelled from behind in the middle line so as to form an acute point of some
considerable elevation, and this gives them the appearance of being arched forward.

The Cephalon is not very much expanded, and almost fills the interval between the
first pair of lateral processes ; in front it bears a pair of tubercular processes directed
outwards, one at the base of each of the chelifori.

The Ocular tubercle is just behind the centre of the cephalon and is very stout, taller
than any of the transverse ridges, and terminates in a cone above four well-developed eyes.

The Abdomen is not separated from the body by an articulation ; it is of normal
proportions, elongate, ovate and directed slightly upwards.

The entire body is covered with short, fine sete, but they appear to be deficient
between the ridges, and to some extent on the cephalon. Ventrally the transverse
ridges are rounded, and the median spur much less prominent than dorsally ; the sete
also are deficient. The length of the body is 13 mm., and its extreme width is 8 mm.

The Proboscis is short and stout, being barely 5 mm in length, cylindrical, shghtly
swollen in the middle, and movably articulated to the body.

The Chelifori are rudimentary, they lie close together above the proboscis and are
more than half its length. The scape is half the length of the proboscis, very slightly
enlarged distally and clothed with short sete; the chele are only knobs, also setose,
and with but vestiges of the fingers.

The Palps rise laterally below the chelifori and comprise nine joints (fig. 2a). The
first joint is short and stout, the proportions of the various joints being: 1°5:4:1:3° :
1:1:1°3:1:1°5. The entire appendage is covered with fine setae which become numerous
on the fourth joint; on the four following joints they form a dense patch covering the

H

50 T. V. HODGSON.

whole ventral surface, and extending dorsally in a very small degree on the first of these
joints but progressively more and more as the extremity of the appendage is approached.
The terminal joint is completely covered, but they are most abundant ventrally.

The Ovigers are ten-jointed and rise ventrally in the angle formed by the cephalon
and the first lateral process (fig. 2b). The first six joints form the normal double
curve and are all more or less covered with small setae on the outer part of the
curvatures. The proportions of the various joints are: 1°5 :3°25:2:3:3:2:2:2:15:2.
The last four joints are provided with a few large spinous sete forming, on three
of the joints, a small irregular group ventrally near the distal extremity ; on the terminal
one, which is much the most slender, they are scattered along its length, one of them
taking the place of the terminal claw.

The Legs are not all the same size, the third pair being the longest and the first
the shortest, their respective lengths being approximately 30 mm., 35 mm., 39 mm.,
37°5 mm. ‘The third leg of the right side has been measured. Of the three coxe the
second is longer than either of the other two, the three together attain a length of
8 mm., and the proportions of the other joints are as 9°25: 9:8 : 3:5, the last figure
representing the tarsus and propodus together. The entire appendage is densely
clothed with rather short but fine setae having no special arrangement, except that on the
femur and first tibia they are not so numerous laterally. The tarsus is small, cuplike,
densely setose, but with no strong spines. The propodus is slightly curved, densely
setose, and with an oblique termination to the joint, but the process from which the
large terminal claw and its two moderate-sized auxiliaries arise projects beyond the joint
itself. The ventral margin of the propodus is spinose but varies greatly. In the best
instance there is a series of eight spines, the first four are small and then they increase
in size rapidly to the last, which is very large. These occupy the proximal half of the
joint. Then follows another series of six of nearly uniform size and not so large as
the biggest of the previous series. This second series occupies the remainder of the
joint and are disposed radially. In other cases the first series is not so well developed
and the second is deficient.

The single specimen of this species is an adult female, the Genital apertures are
found near the middle of the second coxz of all the legs.

Taken in 300 fathoms off the Barrier. Bottom: mud. January 27, 1902.

LEIONYMPHON GLACTALE.
(Plate VII., fig. 3.)

Specific characters :-—
Body well built, with three very prominent transverse ridges produced to a point in the mid-dorsal
line. Lateral processes rather widely separated, and with the stumps of spur-like processes distally.
Proboscis large, but shorter than the body, pyriform.
Palps 9-jointed, the five terminals being sub-equal in size.
Oviger 10-jointed (not mature).

This is a large and comparatively slender species.

PYCNOGONIDA. ol

The Body is well built with the lateral processes rathér widely separated, and
traversed by three very prominent pyramidal ridges which conceal the segmentation.
These ridges are directed backwards to a very slight extent and excavated posteriorly ;
it is in the hollow thus formed that the segmental divisions may be seen. Three ridges
are equally prominent ventrally, but they are not produced to a median point.

The Cephalon is not very much expanded, and a neck is not noticeable.

The Ocular tubercle is stout, not as tall as any of the three transverse ridges, and
bears four well-developed eyes, above which it terminates in a short cone.

The Abdomen is rather long, directed obliquely upwards, not separated from the
trunk by an articulation, and terminating in a blunt point. The cephalon bears a
small blunt tubercle at its anterior margin on the outer side of the base of the chelifori,
a pair of similar tubercles occur dorsally at the extremity of the lateral processes ;
smaller ones also on the first coxee with traces of them on the second. The leneth of
the body is 12 mm., its extreme width is 7 mm. ‘The entire body is scabrous, a feature
most distinctly noticeable on the transverse ridges and the abdomen.

The Proboscis is large, rather pyriform in shape, and measuring 10 mm. in
length. It is movably articulated to the body on a large base, and widens slowly for
one-third of its length where it is very slightly constricted; it is then enlarged
again, and tapering very slightly, ends in a rather broad round point, the triangular
mouth being of moderate dimensions. The proboscis is smooth, and its distal two-
thirds are marked by three pairs of longitudinal bands, transversely divided near
the tip.

The Chelifori are rudimentary and lie close together above the proboscis. The
scape is short, slightly curved and enlarged distally ; the chelze are well developed,
as long as the scape, one half of their length is taken up by a bulbous palm; the
fingers are slender, quite smooth and much curved, but those of the two appendages
are not exactly alike. With the exception of the fingers the entire appendage is
scabrous.

The Palps arise laterally just outside the chelifori, and comprise nine joints
(fig. 3a). The first is short and stout, the proportions of the second and fourth are
as 8 to 11, the third being but little longer than the first; the remaining five are
short and sub-equal, the middle one and the last being a trifle the longest, together
they scarcely equal the length of the fourth. The fourth joint possesses a prominent
tubercle with a glandular opening at two-thirds of its length. The entire appendage
is more or less plentifully clothed with very minute spinous sete; these however are
only conspicuous on the ventral margin of the five terminal joints and at the end of
the terminal one.

The Oviger is ten-jointed and rises ventrally immediately in front of the first
lateral process, and appears to be that of a female (fig. 3b). It is not fully developed.
The first joint is short and stout, the two following are twice as lone and sub-equal,
the third having the usual oblique termination. These three joints form a natural

H 2

52 T. V. HODGSON.

curve in one direction, and the three following curve in another. Measured in their
extreme length the proportions of the various joints of the appendage are: 3:6:6:8:
775:7:4:4:2°:4. The third and following joints are all more or less covered with
very short stout setze on the outer side of their curvature ; these sete are most con-
spicuous on the fourth, fifth, and sixth joints, on the last of which they are also lateral.
The last four joints each bear a small number of stout but simple spines, 4: 8 : 7 : 6, not
arranged in a single row. The last joint tapers to a blunt point, and is without a
terminal claw, a small group of these spines taking its place.

The Legs attain a length of about 55 mm. Of the three coxze the second is twice
the length of the other two, the proportions of the remaining joints being 13°5 : 12:
16: 4, the last figure representing the tarsus and propodus together. The coxe are
densely clothed with very minute sete, but on the femur they are much larger,
though still small, and more conspicuous. They are arranged as a dorsal and a ventral
band, separated laterally by a considerable interval, along the centre of which is a
narrow band of similar sete. This arrangement is continued along the tibiee but it
is not so distinct on the second. The distal fringes are quite normal and incon-
spicuous. The tarsus is a very small cup-like joint, covered with spinous sete
ventrally, with a few prominent ones distally. The propodus is uniformly covered
with small spinous sete, but ventrally there is a row of stout spines running
the whole length of the joint. These spines are very irregular; beginning from the
proximal end the first three or four rapidly increase to large dimensions, the rest are
very irregular in size, but none are so large as the last of the proximal series. The
joint terminates obliquely, the dorsal projection is not large; the terminal claw is
stout, and its two auxiliaries are quite half as long, arising together from a process of
the oblique termination.

The single specimen of this species is immature, and was taken in Winter Quarters
at a depth of 125 fathoms.

AUSTRODECUS.

Body stout, and distinctly segmented, with lateral processes close together. Ocular tubercle
anteriorly situated, long, with four well-developed eyes.

Proboscis immovably articulated to the trunk and ventral in position ; long, tapering, slender.

Chelifori absent.

Palps 6-jointed.

Oviger 6-jointed ? no terminal claw.

Legs short; genital apertures on the second cox of all the legs in female. (Male as yet
unknown.)

I have considered the affinities of this and of the succeeding genus in the intro-

duction to this memoir.

PYCNOGONIDA. 53

AUSTRODECUS GLACTALE.
(Plate VIIL., fig. 1.)

Specific characters :—
Body stout, segmented, with lateral processes close together.
Proboscis long, tapering and curved near the extremity.
Chelifori absent.
Palps 6-jointed ; terminal joint articulated to one side of the penultimate.
Ovigers 6-jointed ?
Legs short, first coxee armed dorsally with two spurs.
Abdomen long and slender.

This is a diminutive species ; the entire animal does not cover a space 8 mm.
square.

The trunk is stout and distinctly segmented ; the lateral processes are not widely
separated, but as they are rather short and tapering, the intervals at their distal
extremities are very pronounced. The first coxee, which are the largest, all bear
dorsally a pair of stout tubercular spines which are very prominent. Each of the four
segments of the trunk bears a stout tubercle of some elevation in the middle line, and
close to its posterior border.

The Cephalon is scarcely expanded, and almost fills the interval between the first
pair of lateral processes and their first coxee. Anteriorly it bears a very long Ocular
tubercle which is directed obliquely forwards, flask-shaped and truncated at its extremity,
on the upper surface of which, in a compact group, are four very well-developed eyes.

From the truncated end of the trunk the Abdomen projects horizontally ; it is rather
long and not separated by an articulation. On the ventral surface of the trunk a
slightly raised band passes transversely between the first three pairs of lateral processes,
with the last pair the band is interrupted in the middle line.

The Proboscis is long and of a peculiar shape, not unlike the snout of a weevil
beetle. It is movably articulated to the body, and for about one-third of its length it
is not disproportionately slender, then it tapers rather rapidly to a long and very
slender structure, curved downwards near the tip. It is quite smooth and presents an
annular appearance which is less distinct proximally.

The Chelifori are quite absent.

The Palps are six-jointed and arise above but well to the side of the proboscis
(fig. 1b). The first joint is short and very stout, the second is long and extends
beyond the extremity of the ocular tubercle. The third is very short and its distal
limit indistinct. The fourth joint is rather more than half the length of the second.
The second joint bears the stumps of several spinous setze along its length; on the
fourth joint a similar number of curved spinous sete occur, and these increase in size
to the distal extremity of the joint, which also bears a few finer sete and a small
distal fringe. The last two are quite small and rather densely clothed with small sete.
The last one is articulated to one side, and not at the end, of the penultimate, and
the setze occur mainly on the outer side.

54 T. V. HODGSON.

The Ovigers arise ventro-laterally, close to the angle formed by the cephalon and
the first lateral process. They are extremely small, and it is open to question whether
they are mature or not. As the removal of one of these appendages involves serious
risk to the only specimen, it cannot be very satisfactorily described. Not less than
six joints can be distinguished, the first three of which are very small. “A small body-
process from which the appendage arises may be an additional joint. The terminal
joint is the longest, it is rounded at the extremity and does not carry any trace of a
claw, nor are sete: of any kind discernible.

With regard to the Legs. the first coxa has already been alluded to as the largest
of the three, the other two are very little if any shorter, and the second is dilated
distally. It is difficult to get the limb in one plane for measurement, and the
joints appear subject to some variation. The proportion of the joints appears to be
3°5: 8: 2°5: ‘5: 2°5. The femur is stout, and the two following joints decrease in
calibre. The limb bears a very few scattered setee, most numerous on the second
tibia. The tarsus is very small and cup-like, with two or three spinous sete
ventrally ; the propodus is proportionately long, slightly curved, and bearing a few
sete. On its ventral margin it carries a row of sete, but there is nothing very
distinctive about them. The claw is short and stout, and is accompanied by two
slender auxiliaries.

The only example of this peculiar species is a female, and the Genital apertures
are found in the middle of the second coxee of all the legs.

Taken by the dredge in Winter Quarters before the ship was frozen in. Ten
fathoms or less.

AUSTRORAPTUS.

Body with spurs on the lateral processes and first cox. Segmentation very imperfect.

Proboscis stout at the base, terminating in a point.

Chelifori rudimentary.

Palps 6-jointed.

Ovigers 10-jointed, without terminal claw or denticulate spines.

Legs comparatively long, terminal claw with two auxiliaries.

AUSTRORAPTUS POLARIS.
(Plate VIIL, fig. 2.)

Specific characters :—

Body rather stout, with prominent spurs on the lateral processes and the first cox.

Proboscis half the length of the trunk, pointed.

Palp 6-jointed, the terminal joint is twice as long as its predecessor, and articulated at an

angle to it.
Oviger 10-jointed, without terminal claw or denticulate spines.
Legs long, terminal claw with two small auxiliaries.
The body is rather robust, with long lateral processes which arise close together

and diverge considerably. These are provided dorsally with a pair of stout tubercular
spines which exist also on the first coxee, where they are greatly exaggerated.

PYCNOGONIDA. 55

The Cephalon is considerably enlarged, and almost completely fills the interval
between the first pair of lateral processes.

The Ocular tubercle is stout and tall, terminating in a cone above the four
well-developed eyes. It lies well to the front of the cephalon.

The Abdomen is long, cylindrical, almost horizontal, and not separated from
the body by an articulation. The extreme length and breadth of the trunk is as
6 to 5°5, the abdomen increasing the length to 7°5. The articulation of the trunk
is indistinct, that separating the last seement being non-existent, The entire body
appears to be perfectly smooth.

The Proboscis is about half the length of the trunk; it lies underneath the
cephalon, directed obliquely downwards; it is stout and cylindrical for the greater
part of its length, tapering off to a sharp cone. It is movably articulated to the
trunk,

The Chelifori are rudimentary; the scape is well developed, stout, not setose, a
little longer than the cephalon; the chelz are reduced to a knob, inclined inwards at
an angle of about 45°, with only the merest traces of fingers.

The Palp is short and only possesses six joints. It rises close to the proboscis,
below and outside the chelifori (fig. 2a). The first joint is short and stout, and
the second is three times as long; the third is again very small and, forming an
elbow, is shorter on one side than the other. The fourth is the longest joint,
though but little longer than the second, the only sete visible forming a small
distal fringe. The following joint is characteristic; it is small, and its inner margin
is just half the length of its outer border; this outer border is well supphed with
sete distally. To the oblique termination of this joint the sixth and last joint
is articulated. It is twice the extreme length of its predecessor and richly setose on
its outer border and extremity.

The Oviger is 10-jointed and rises ventro-laterally at the angle formed by the
first lateral process with the cephalon (fig. 2b). It is a short appendage ; the first
three joints are short and stout, the second and third are sub-equal in length, but
not in diameter, and nearly twice the length of the first; the two following are the
longest joints, the fifth being a trifle longer than the fourth and sparingly setose ;
the sixth is short, the seventh is longer, and the three terminal ones progressively
decrease in length and diameter, the last one being very small. The last five joints
are sparingly supplied with sete. On the terminal joint there are three long and
stout ones. There is no terminal claw nor are there any special spines. The oviger
of the male has not been removed, but does not differ essentially.

The Legs measure some 18 mm. in length. The second coxa is fully as long as
the other two together, and is much enlarged distally. The femur and first tibia are
sub-equal in length, and the second tibia is a very little longer; the tarsus and
propodus together are rather more than one-third the length of the second tibia. The
tarsus is very small and cup-like, richly setose ventrally, the sete being stout, one

as

56 T. V. HODGSON.

especially so. The propodus is very slightly curved and covered ventrally with
short spinous sete, with, proximally, a row of four stout spines. Dorsally the sete
are small and scanty. The terminal claw is large, more than half the length of
the joint, and accompanied by two small auxiliaries. These claws arise on a process
from the oblique termination of the joint. The extreme end does not project much
beyond, and is supplied with numerous spinous sete. The rest of the limb, coxe,
femur, and tibie are fairly well covered with very small sete; their precise
distribution is not easy to observe, but they appear to be deficient laterally ; they
are most abundant on the second tibia. The lateral line is well marked on the
three largest joints.

The specimen above described is an adult female, and shows conspicuous Genital
apertures on a swelling at the extremity of the second coxa of all the legs. An
adult male shows smaller apertures on the three posterior legs only.

The female was taken in 100 fathoms, rough ground, off the Barrier, in
Lat. 78° 16’14” S., Long. 197° 41' 47” K.

The male was taken in 300 fathoms, mud, off the Barrier, in Lat. 71° 25'40"S8.,
Long. 185° 39’ 06” E.

RHYNCHOTHORAX.
Rhinchothorax, O. G. Costa, Microdoride Mediterranea (1861), p. 7.

1 have not seen Costa’s original description of this genus or its attendant species.
In the ‘Challenger’ Report (14) it is included by Dr. P. P. C. Hoek in his list of
the then known species of Pycnogonida, and at the same time condemned as being
insufficiently described. It is not a little remarkable that out of ten species then
recorded from the Mediterranean only one is described in Dr. Dohrn’s monograph (8).
Zoologists are indebted to that author for the careful and full descriptions of the
Pycnogonida therein recorded. The genus and species of Rhinchothorax mediterraneus
Costa are fully described, and differ in many particulars from the original description.

Dr. Dohrn states—

That the Chelifori are absent.

That the Palp is eight-jointed, but that fusion has taken place, reducing
the number of distinct joints to five. Five distinct joints are figured,
the limits of the remainder being obscure.

That the Ovigers are eleven-jointed. In both figures, however, only ten
joints are shown.

I have no hesitation in placing the species described below in the genus Rhyncho-
thorax as defined by Dr. Dohrn for these reasons: the general aspect of the animal is
similar; the proboscis is cleft at its extremity ; though the palps are only five-jointed,
the feebly-developed extremity seems to indicate some reduction is taking place; and
the ovigers are ten-jointed, and the exact counterpart of those figured by Dr. Dohrn.

*

PYCNOGONIDA. 57

RHYNCHOTHORAX AUSTRALIS.
(Plate VIIL, fig. 3.)

Specific characters :—
Body very robust, with lateral processes quite close together, and with median tubercles on
the segments.
Chelifori absent.
Palps 5-jointed, the second joint with a very strongly developed spur dorsally.
Ovigers 10-jointed, with a terminal claw, the last four joints with a couple of spines on an
enlarged base.

Legs short, terminal claw with two small auxiliaries.

Body very robust, with the lateral processes short and quite close together, widest
across the first lateral process, and about half the breadth across the last.

The posterior articulation of the trunk is deficient, but immediately in front
of where it should be, as on the preceding segments, is a stout median tubercle, bluntly
pointed, and very slightly inclined forwards.

The Cephalon is expanded, but very short. The Ocular tubercle, which is stout,
projects forwards and upwards over the base of the proboscis. It bears four well-
developed eyes, the posterior pair being a little the larger, and terminates above them
in a short cone. Measured from the anterior margin of the ocular tubercle, the
cephalon is half the length of the first segment of the trunk.

The Abdomen is long, about as long as the two combined segments from which
it originates.

Proboscis is stout, conical, a little longer than the first trunk segment. A
conspicuous slit marks the mouth as the animal lies in its normal position.

Chelifori, no trace.

Palps. These appendages only comprise five joints, and are very curiously
modified (fig. 3a). Hach rises at the side of the proboscis and extends but little
beyond it. The first joint is short and stout, the second is the longest of the
appendage ; its dorsal extremity is prolonged forwards and upwards as a stout spur.
The third joint is about half as long as the shaft of the second, it is enlarged distally,
a stout dorsal tubercle bearing a tuft of sete; a few other sete are more scattered.
The fourth joint is small and setose, while the fifth, which is also richly setose, is
reduced to a mere button.

The Oviger is very slender, ten-jointed, and rises ventro-laterally at the neck
(fig. 3a). The first three joints are short, and progressively lengthen, but only to a
slight degree. The fourth is nearly as long as the three together. The fifth is
shorter, but swollen distally. The sixth is shorter still. No sete are discernible on
any of these jomts. Of the four terminals the first three are sub-equal in length,
but their dorsal surfaces become more and more curved. Ventrally, also, there are
prominent projections which bear the denticulate spies. The terminal joint is very
broad, and a little longer than the others; its dorsal outline is very much curved,
and ventrally a large swelling occupies almost the whole surface; one small spine is

I

58 T. V. HODGSON.

all that is visible. A prominent claw terminates the appendage. The denticulate
spines are few in number, two on each of the first three joints. They are worn, and
all that remains is a slender shaft of uniform diameter with three terminal teeth, of
which the middle one is the largest.

The Legs are short. The three cox are short and stout, the second is by a very
little the longest, but the first has nearly twice its diameter; it also bears a tubercle
smaller than, but similar to, those borne on the middle line of the trunk. The femur
is stout, and not so long as the three coxze together, but the remainder of the
appendage is much more slender. The proportions of the two tibie are as 3 to 2,
the tarsus and propodus together being as long as the second tibia. The tarsus is a
very small joint, its ventral surface being covered with minute spinous sete. The
propodus, which is curved, has a row of them along its ventral margin, separated by
rather wide intervals; several sete are scattered dorsally. The terminal claw is
stout and is accompanied by two slender auxiliaries about one-third its size. A few
setee are scattered on other parts of the appendage, but they do not form a prominent
feature.

The Genital apertures are distinct on the second cox of the last pair of legs only,
and this joint is much swollen in consequence.

This species, of which there is only a single specimen, was found by Mr. Kirk-
patrick on a sponge. Winter Quarters, at a depth of 178 fm., 7 Aug., 1902.

COLOSSENDEIS.

Body ovoid or elongate, with the lateral processes close together or widely separated, as a general
rule without segmentation. Cephalon small. Eyes well developed or absent.

Proboscis very large, often much longer than the body, and movably articulated to it.

Chelifori very rarely present, rudimentary.

Palps very long, 10-jointed, third and fifth joints the longest, more or less setose.

Ovigers very long, 10-jointed, fourth and sixth joints the longest, the last four joints bearing
several rows of spines usually dentate. A terminal claw.

Legs without auxiliary claws ; the three coxal joints short.

Abdomen of moderate dimensions, movably articulated to the trunk, sub-clavate.

Genital apertures on the second coxa of all the legs.

I defined this genus in comparison with Decolopoda in the Zoologischer Anzeiger
(13), retaining as far as possible the words of Jarzynsky. Certain characters made
use of by Professor G. O. Sars (25) have been incorporated, since his definition has
become inapplicable in certain important features.

No less than eighteen species and two varieties have been described. Through
the generosity of Professor E. L. Bouvier I have been permitted to examine the
collection of Colossendeids made by the ‘ Travailleur’ and ‘ Talisman,’ the description
of which is not yet published. The identity of these species with the known species,
or otherwise, has not yet been fully established, but four new species from the
Antarctic Regions are now described.

PYCNOGONIDA. 59

COLOSSENDEIS AUSTRALIS.
(Plate IX., fig. 1; Plate X., figs. 1 and 2.)

Specific characters :— )
Body stout, with lateral processes widely separated, minutely scabrous, the spines being arranged
in distinct rows on the appendages.
Proboscis enormous, bottle-shaped, more than half as long again as the body. Eyes, four, well
developed.
Palp 10-jointed, the eighth and ninth joints equal, the tenth longer.
Claw of legs less than half the length of the propodus.

Under a lens the entire animal exhibits a beautifully mottled appearance, which,
to a greater or less extent, appears to be characteristic of the genus. The Body
shows the faintest traces of segmentation ; the cephalon is short and only very little
expanded, and the first pair of lateral processes is, placed close against it..

The Ocular tubercle is situated in the middle of this area and is stout, with four
well-developed eyes, two anterior and two posterior, the latter smaller than the others.

The Proboscis is of much greater diameter than the body, to which it is movably
articulated ; throughout the greater part of its length it is curved downwards; the
mouth is very large. The organ is covered with minute spines, which seem to have, to
some extent at least, an indistinct linear arrangement; the difficulty of making out
their precise arrangement is accentuated by a growth of polyzoa.

‘The Abdomen is of moderate dimensions and somewhat clavate.

The ten-jointed Palp arises ventro-laterally, as close as possible to the proboscis.
The two first joints are very short, and the third is rather more than twice the length
of the fifth; the fourth is small; the sixth is barely one-third the length of the fifth,
and the seventh is about half as long again as its predecessor; the eighth and ninth
are shorter and sub-equal ; the terminal one is absent from one side and injured on the
other, but in the other specimen available it is a little longer. The lateral line appears
along the greater part of the appendage. The entire limb is spinose, beginning with
the third joint, and the minute spines are arranged longitudinally in rows as far as the
end of the fifth joint, which, with the two preceding, bears a more or less complete
whorl of spines at its distal extremity. Beyond the fifth joint the spines become stiff
setee rather than spines; they are larger and more abundant and irregular, besides
being aggregated on the ventral and inner side in the natural position of the limb.

The Ovigers are very long and, as characteristic of the genus, 10-jointed (fig. 1a).
They arise from a small body-process immediately behind the palps, but nearer the
middle line. The first three joints are small, the fourth and sixth are the longest and
sub-equal, the fifth being about a quarter their size. The last four are sub-equal, and
the appendage terminates in a small claw. The lateral line is distinctly marked. The
entire limb is spinous. A few minute spines exist on the first three joints, beyond
these they are arranged more or less clearly in lines and are more numerous. There

is also a fringe of small spines on the outer margin of the distal extremity of each
I 2

60 T. V. HODGSON.

joint, but these are either inconspicuous or absent on the four terminal joints. With
regard to the characteristic groups of spines on the four terminal joints, there are four
rows on the three proximal joints and three only on the terminal joint. In both
specimens the spines are so much worn as to give but a feeble idea of their true
character (Plate X., figs. 1 and 2). The large size of the sockets in which they are
planted is remarkable. The most ventral row, that which lies nearest the sea
bottom in the natural position of the animal, comprises a small number, less than a
dozen, of large stout spines. The second row, which in this species is not separated
from the first by any conspicuous interval, contains approximately double the number
of smaller spines; the sockets of this row are sometimes crowded together, and the
spines are smallest and most crowded at the proximal end of the joint, and are also
deflected from a straight line by the articulation of the succeeding joint. Two other
rows follow, but these have not the mathematical regularity of the former, nor are
they so much deflected ; they are reduced in number, but not in size. In structure the
large spines appear to consist of a stout base almost circular in section and composed
of a strong chitinous investment having a protoplasmic core; the spine tapers to
a blunt point much worn, but with enough left to indicate a flattened blade at the
extremity.

The Leg attains a length of 115 mm. The three coxe may be regarded as
sub-equal in size, and short. The two tibiz are the longest joints and sub-equal, except
in the first leg, where the second tibia is a trifle shorter than the first. The femur is ¢
little shorter, and the tarsus less than half the length of any of the three preceding
joints ; the propodus is just over half the length of the tarsus. On the first coxa
there is dorsally and ventrally a median line of reddish colour, which appears to
indicate the presence of a slight groove. On the second coxa the lateral line begins
on each side of the joint, and passes to the extremity of the limb, The three coxze
are minutely scabrous and possess a small fringe of minute spines at their distal
margins. The remaining joints are more or less covered with these fine spines,
which become a little more conspicuous as the extremity of the appendage is reached.
Six rows are fairly well defined throughout the limb, a median dorsal, a median ventral,
and two lateral, one on each side the so-called lateral line. The distal extremity of
ach joint bears a fringe of spines on the inside of the bend, largest and most
conspicuous on the second tibia. The terminal claw is small, less than half the
length of the propodus.

The Genital apertures occur on the second coxa of all the legs in both sexes,
as shown in figs. 1b and le,

The above description has been prepared from an example taken in deep water.
Another from shallow water presents certain differences: first, it is more spinose,
especially the proboscis and the limbs; on the legs four additional irregular rows of
spines may be distinguished between the six described for the deep-water specimen,
iwo of these are dorsal and two ventral: and secondly, in the comparative length of

PYCNOGONIDA. 61

certain joints. The third joint of the palp is distinctly less than twice the length of
the fifth, and the fourth joint of the ovigerous leg is a little longer than the sixth.

The nearest ally of this species seems to be C. proboscidea, Sabine, from which,
however, it may be instantly recognised by the wider intervals between the lateral
processes and the presence of well-developed eyes.

Two specimens of this species were taken, one off Cape Wadworth, Coulman Island,
8-15 fm.; bottom : stones; the second off Mounts Erebus and Terror, 500 fm.; bottom :
stones.

This latter specimen is the carrier of some half-dozen cirripedes of the genus

Scalpellum.

CoLOSSENDEIS GLACIALIS.

(Plate IX., fig. 2; Plate X., figs. 3 and 4.)
Specific characters :—
Body apparently smooth, with lateral processes widely separated, and four well-developed eyes.
Proboscis not quite so long as the trunk, slightly dilated about the middle, and covered with short

spinous sete.
Palps, three terminal joints sub-equal and densely setose, with wide and deep constrictions at

the joints.

The body is rather stouter proportionally than the last two species, and though
apparently smooth, a lens reveals a median row of extremely minute sete.

The Cephalon is not expanded beyond the average width of the body.

The Ocular tubercle is stout, and bears four eyes, the anterior pair larger than the
posterior ; the portion above the eyes is acutely pointed, but this feature is variable
in size. The setous character of the proboscis is not always easily discernible ; in one
specimen it is prominent, in others less so, even when not concealed by a growth of
polyzoa. It can hardly be said that these setee are arranged in any definite manner,
but in places they give the impression of ill-defined rows.

The Abdomen is short and articulated to the trunk. The Proboscis is as defined
among the specific characters and flexibly united to the trunk,

The Palps arise on the ventral side of the proboscis (fig. 2); the first joint is
rather more prominent than usual, and is readily seen from the dorsal surface. The
second joint is shorter, the third is considerably the longest of the appendage, the
fourth is quite short, and the fifth is approximately two-thirds the length of the
third; this joint has a faint constriction at about two-thirds of its length. The
following joint is short, the next a little longer, the three terminal joints being short
and sub-equal, The extremity of the palp has a peculiar appearance, owing to the
seventh, eighth, and ninth joints, and to a less extent the sixth, having their distal
extremities rounded off like the shoulders of a wide-mouthed bottle, so that each
joint seems balanced on a narrow base. The entire appendage is beset with stiff sete,
almost spinous in character. On the third joint they are short, somewhat sparsely
distributed, and appear to be arranged in rows. A whorl of stouter setze (spines ’)

62 T. V. HODGSON.

surround the distal extremity of this joint and the next ; beyond this the setze are so
thickly distributed that it is scarcely possible to make out any definite arrangement.
On the fifth joint some of the sete are distinctly longer than the majority, and from
this joint the sete on the inner side of the appendage, in its natural position, are much
the longest. .

The Ovigers arise immediately behind the palps on a conspicuous body-process
close to the middle line (fig. 2a). The first three joints are small, and bear spinous
setee of small size. The fourth and sixth are very long and sub-equal, the fifth being
not more than a quarter of their length. The four terminal joints are sub-equal in
length, but decrease in stoutness. The entire appendage is setose. On the fourth
joint the sete are small and arranged in rows, and on the outer margin, at about
two-thirds of its length, a small but distinct, rounded protuberance occurs. On the
succeeding joints the sete or spines, whichever they may be called, are more thickly
distributed. The characteristic spines of the four terminal joints present very slight
differences from the two preceding species. On the ventral side of the limb in its
natural position are two rows of these spines separated by a conspicuous interval ; the
more ventral of these two rows consists of a few large spines, the other contains
approximately double the number of smaller spines. Dorsally, and separated by an
interval, are two rows of smaller spines, which are not, however, arranged with such
precision as the others. Close examination reveals the fact that the intervals between
the rows of spines are more apparent than real, this effect being due to the set of the
first two rows and the third group or double row; the second row is deflected at the
extremity by the articulation of the succeeding joint. The spines do not present
any special peculiarities, being more like true spines than in the other species here
described. They are somewhat curved or falciform (Plate X., fig. 3). The terminal
claw is of moderate dimensions, rather slender, but with a stout base ; in most of the
specimens the stout base is all that is left. All four terminal joints are dorsally
covered with short spinous sete set in sockets (Plate X., fig. 4). In this species they
are much more numerous than in the other three.

Concerning the Legs, the first coxa has a slightly greater diameter than the others,
and bears the dorsal and ventral mark so characteristic of the genus. The other two
coxee are nearly equal in length and all are minutely spinose. The Genital apertures
occur on the second coxe of all the limbs, and the lateral line beginning on that
joint is conspicuous to the end of the limb. The first tibia is the longest joint of the
limb, the femur is very little shorter, the second tibia approximates to three-quarters
the length of the first, and the tarsus to very nearly half its length; the propodus is
shorter than the tarsus by nearly a third, and the claw is less than half the length of
the propodus. The entire limb is covered with minute sete, which, along the dorsal
surface at any rate, have a distinct linear arrangement; ventrally this becomes
indistinct from the second tibia onwards. The distal extremity of each joint,
including the cox, is ntore or less completely girdled with spines, minute up to

PYCNOGONIDA. 63

the extremity of the femur, and most numerous dorsally ; on the first tibia they
increase in size ventrally, and still more so on the second tibia; on the tarsus and
propodus the ventral setee are comparatively long and conspicuous.

The specimen from which the above description was taken seemed to be an
exceptionally spinose individual. Seven specimens were obtained, and in the other
six all the features described above can be seen, though to a less degree, when not
concealed by a growth of polyzoa,

Winter Quarters, 12 to 25 fathoms.

COLOSSENDEIS FRIGIDA.
(Plate IX., fig. 3; Plate X., figs. 5 and 6.)

Specific characters :—
Body smooth, with lateral processes widely separated. Four well-developed eyes.
Proboscis approximately twice the length of the trunk, dilated about the centre and quite smooth.
Palps, 10-jointed ; eighth joint half the size of the two terminals, which are sub-equal.
Ovigers, with a group of four or five irregular rows of special spines in addition to the two
primary rows.
Claws of legs about half the size of the propodus.

This last character, together with the spines and terminal claws on the ovigers,
readily separate this species from C. megalonyx, to which it appears very closely
related.

A considerable amount of latitude must be allowed on the proportions of the
joints of the various appendages as a guide to specific discrimination. Thus the
proboscis varies in length from 11 mm. to rather more than 21 mm., and the trunk
to the base of the abdomen, from rather less than 6 mm. to rather more than 11 mm.,
but the longest proboscis does not coincide with the longest body. The same sort of
variation occurs throughout.

There is no trace of segmentation in the trunk, and the Proboscis is articulated to
it, hence the variation of the angle to which it may be inclined.

The Ocular tubercle is stout, sharply conical above the eyes, which are well
developed and four in number.

The Abdomen is quite small and articulated to the trunk.

The Palps are ten-jointed. The third joint is much longer than the fifth, which
reaches almost to the extremity of the proboscis. The fourth joint is very small, and
the seventh is slightly longer than the sixth; the eighth is quite short, the two
terminals being twice its size and sub-equal. Towards the extremity of the fifth joimt
very minute seta make their appearance, and on the rest of the appendage they are
scattered in more or less definite rows.

Ovigers : These appendages arise close to the middle line behind the palps (fig. 3).
The first three joints are very small, the fourth and sixth long and sub-equal, the
sixth as a rule extending beyond the proboscis. The fifth joint is about half the
length of the sixth. The four terminal joints are sub-equal, and the claw has a
peculiar appearance, as if the inner margin had been bevelled off at a very acute

64 T. V. HODGSON.

angle. In its perfect condition it is rather long and slender, especially the distal
half, Something like one-half of this slender portion, at the tip of the claw, is
flattened dorso-ventrally to form a sort of protective shield to a thin membranous fold
lying like a knife-edge on the under surface of the claw throughout its distal half
(fig. 3a). The claw is covered with very minute hairs. The characteristic spines are
very numerous, and are arranged in two sharply defined lines followed by a closely
arranged group in which five rows can be distinguished. A distinct interval separates
the first two rows from each other and from the group referred to above. The
spines of the first row are long, slender, lanceolate in shape, and set as closely
together as possible (Plate X., figs. 5 and 6). Those of the second row are approxi-
mately double in number, shorter and more spathulate, their essential structure being
the same. They have a fairly stout base tapering to the centre, where it becomes
a flat blade, the entire margin of which is provided with minute teeth visible
under a one-inch objective. In the group of spines there are five rows arranged
in an imbricate manner and as the spines of these rows alternate fairly regularly
oblique rows of eight spines may be distinguished in the broadest part of the group.
In structure they resemble those of the second row. Set are sparsely distributed
over the appendage and though very minute they are not difficult to distinguish.

The legs of the numerous specimens average between 58 mm. and 106 mm. in
length; the proportions of the joints do not, however, vary greatly. The first coxa
bears a reddish line marking a very shallow groove dorsally and ventrally ; the lateral
line begins on each side of the second coxa, and is continued to the extremity of the
limb. The three cox are sub-equal. The femur is the largest joint of the limb
as a rule, the other joints decreasing in size to the extremity. The claw is about half
the length of the propodus.

The Genital apertures oceur on the second coxa of all the limbs of both sexes. The
legs are apparently quite smooth, even to the touch, but close examination shows faint
traces of rows of setee. In some of the larger specimens these are a little more conspicuous.

Specimens of this species were taken in Winter Quarters in depths varying from
5 to 178 fathoms, and the name is derived from the fact that two of them had to be
taken to the ship dry, a distance of nearly two miles, at a temperature of —50° Fahr.
They suffered in consequence. Another specimen taken in 300 fathoms ; bottom, mud ;
off the Barrier, 27.1.’02, is referred to this species.

COLOSSENDEIS RUGOSA.
(Plate IX., fig. 4; Plate X., fig. 7.)
Specific characters :—

Proboscis half as long again as the body, slender, dilated about the middle, with a median row of
curved spines dorsally along the proximal half.

Body smooth, with lateral processes widely separated, and, with the first coxa, dilating distally.

Palps 10-jointed, the eighth very short ; the ninth rather more than twice its length ; the terminal
one a little larger still.

Legs provided with rows of spines, claw large.

-_*

PYCNOGONIDA. 65

This species in general appearance very closely resembles the last, but may
be readily distinguished by its spiny character and the features quoted above.

The Body is quite smooth, the cephalon short and without any constriction
indicating a neck.

The Ocular tubercle is stout, with four well-developed eyes, the anterior pair
being larger than the posterior pair. Above the eyes the tubercle is acutely conical.

The Proboscis is half as long,as the body as indicated in the specific characters, "|

and besides the median row of spines there is a lateral row of a few, widely
separated. The proboscis is movably articulated to the body, and obtusely pointed
distally.

The Abdomen is small, somewhat clavate, but presenting no special feature.

The Palps arise on the ventral side of the body, as close as possible to the
proboscis. They arise on a process of the body which is usually regarded as the first
joint, but which has always appeared to me to be doubtful whether it is a real joint or
not. In this particular species it is definitely a body-process and not a true joint.
The succeeding joint, here as elsewhere called the second, is very short, a mere ring-
like segment. The third is considerably the longest joint of the appendage, slender
and furnished with a few prominent curved spines; the fourth is quite small; the
fifth is two-thirds the length of the third; and a short distance from the distal
extremity there is a distinct constriction as though there had been a joint there and
it had fused; the sixth is short, and the seventh is about half as long again; the
eighth joint is very short, scarcely half the length of the sixth; the ninth is fully
twice the Jength of the eighth, and the terminal one a little longer, rounded at the
extremity. From, and including the fourth joint, the entire organ is covered with
minute spines, too plentifully distributed to assert any regular disposition.

The Ovigers arise laterally from two body-processes close to the middle line and
immediately behind the proboscis (fig. 4). The first three joints are very small and
sub-equal in length; the fourth and sixth are very long and sub-equal, the fifth being
about one-third of their length; of the four terminal joints, the proximal is the
largest. The claw is of moderate dimensions. The entire appendage is covered with
very minute spines, which become numerous from the fourth joint, and appear to be
very generally distributed. The characteristic spines of the four terminal joints are
limited to four rows with an occasional small spine which may perhaps be regarded
as the remnant of a fifth row. It is unfortunate that in the only specimen obtained
(Plate X., fig. 7) these spines are very much worn. An interval separates the two
first rows, and another interval separates the second row from the remainder.

The spines of the first row are long, slender and few in number. They have
a somewhat stout base which, as far as can be judged without cutting sections,
appears to be rounded on one side and flattened or somewhat concave on the other ;
they are constricted in the middle, and produced onwards as a flat blade with dentate
margins. The spines of the second row are smaller, twice the number, and placed as

K

66 T. V. HODGSON.

close together as possible. In both these rows the spines are set at right angles to
the joint, in the other rows they are arranged parallel to the length of the joint.
All these are essentially the same in character, but in the “ parallel” series, the spines,
heing viewed more laterally, appear to be curved and the blade forms a very
shallow scoop.

The Legs are provided with longitudinal rows of curved spines, not very
numerous, especially on the ventral surface, most abundant and conspicuous on the
femur. The first coxa is conspicuously broader than the others. The lateral
processes of the body are narrow proximally and widen distally, the first coxa
continuing this widening. The two following coxe are of less diameter, sub-equal in
length, the distal extremity of each is fringed with minute spines, the fringe,
however, not being complete. The femur is conspicuously the longest joint of the
limb, the other joints progressively shorten, the amount of decrease being obvious.
The claw is nearly the length of the propodus. A few additional spines are to be
found ventrally at the distal extremity of some of the joints.

The Genital apertures open on the second coxa of each leg.

A single specimen of this species was taken off the Barrier in lat. 78° 25' 40”S.,
long. 185° 39’ 6” E., 300 fms., bottom, mud, 27 Jan. 1902.

In the examination of this collection my thanks are primarily due to the Council
of the Marine Biological Association of the United Kingdom, and to Dr. E. J. Allen,
the Director, for accommodation at their Plymouth Laboratory ; to Professor Chilton,

.of Canterbury College, Christchurch, N.Z., for enabling me to make the preliminary
examination of our collections; to Mr. G. M. Thomson and Professor W. B. Benham,
of Dunedin, N.Z., for so kindly placing the whole of their collections at my disposal ;
to Professor E. L. Bouvier, of Paris, for allowing me to examine the collection made
by the ‘Frangais’ in the Antarctic as well as the unpublished collections of the
‘Travailleur’ and ‘Talisman’; to Professor Kraepelin, and particularly to Dr. G.
Pfeffer, for the opportunity to examine the collection from South Georgia, now in
the Natural History Museum at Hamburg; to Professor A. Brauer, and especially to
Dr. E. Vanhéffen, biologist of the ‘Gauss, for the facilities extended to me during the
examination of the ‘ Valdivia’ and other collections now in the Berlin Museum.

My best thanks are due to Mrs. L. E. Sexton for the drawings of Plates VI.
and IX., Plate II, Fig. 1., Plate V. (the entire animal), Plates X., Figs. 1-7, all of
which were executed with the greatest accuracy. I am further indebted to her for
some considerable assistance during the progress of the work.

Messrs. West, Newman and Co. have continued the preparation ofthe plates,
and I must thank them for the care they have taken.

ae)

ai

Aa
©

10.

11.

13.

14,

18.

19.

PYCNOGONIDA. 67

LIST OF WORKS QUOTED IN THE TEXT.

. Bonu, R. Uber die Pyenogoniden des Konig]. Zoologischen Museums zu Berlin, insbesondere tiber die

von 8. M. 8. Gazelle mitgebrachten Arten.
Monatsber. Akad. d. Wiss. zu Berlin, 1879, pp. 170-195, 2 pl.

. Bouvrer, FE. L. Observations préliminaires sur les Pycnogonides recueillis dans la région antarctique

par la Mission du ‘ Frangais.’
Bull. du Mus. d’hist. Nat., 1905, No. 5, pp. 294-7.

. Bouvier, E. L. Nouvelles observations sur les Pycnogonides recueillis dans les régions antarctiques

au cours de la campagne dirigée par M. Jean Charcot.
Comptes rendus des Séances Acad. des Sciences CXLII., 1906, pp. 15-22.

. CARPENTER, G. H. On some Pycnogonida from the Irish Coasts.

Sci. Proc. Roy. Dublin Soc., Vol. VIIL., N.S., 1893, pl. II., pp. 195-205, 1 pl.

5. CARPENTER, G. H. On the Pantopoda.

In Herpmay, Ceylon Pearl Fisheries, Supplementary Report XIII., pp. 181-4, 1 pl.

5. Conn, L. J. Pyenogonids of the West Coast of North America.

Harriman Alaska Expedition, Alaska, Vol. X., 1904, pp. 249-298, pl. IX.-XXVI.

. Coz, L. J. Ten-legged Pycnogonids, with Remarks on the Classification of the Pyenogonida.

Ann. & Mag. N. H., 7, Vol. XV., 1905, pp. 405-415.

. Donen, ANTON. Die Pantopoden des Golfes von Neapel und der angrenzenden Meeresabschnitte.

Leipzig. 1881.

. Haswein, W. A. On the Pyenogonida of the Australian Coast, with descriptions of new species.

Proe. Linn. Soc., N.S.W., Vol. IX., 1885, pp. 1021-34, 3 pl.
Hepeson, T. V. Crustacea.
Report on the Collections of Natural History made in the Antarctic Regions during the ree of
the ‘Seuthern Cross,’ 1902, pp. 257-8.
Hopeson, T. V. On a new Saito from the South Polar Regions.
Ann. & Mag. N. H., 7, Vol. XIV., 1904, pp. 458-462, 1 pl.

. Hopason, T. V. Scotia Collections. On Decalopoda australis Hights. An old Pyenogonid

re-discovered.
Proc. Roy. Phys. Soc., Edinburgh, Vol. XVIJ., 1905, pp. 35-42, 2 pl.
Honason, T. V. Decalopoda and Colossendeis.
Zool. Anz. Bd. XXIX., 1905, No. 8., pp. 254-6.
Horx, P. P. C. Report om the Pycnogonida dredged by H.M.S. ‘Challenger’ during the years
1873-76.
H.M.S. ‘ Challenger’ Reports, Zoology, Vol. 3. 1881.

5. Horx, P. P.C. Nouvelles études sur les Pycnogonides.

Arch. Zool. Exp. et Gen. LX., 1881, pp. 487-542, pl. XXIIT.—XXX.

. Hong, P. P. C. The Pycnogonida dredged in the Faroe Channel during the Cruise of H.M.S.

‘Triton’ (in August 1882).
Trans. Roy. Soc., Edin., Vol. XX XII., 1883, pp. 1-10, 1 pl.

. Horr, P. P.C. On Four Pycnogonids, dredged during the Cruise of the ‘ Challenger.’

Tijdschr. d. Ned. Dierk. Vereen. (2) V. 2-4, 1898, pp. 290-300, 2 pl.
JARZYNSKY, T. Praemissus catalogus Pyenogonidarum inventarum in mari glaciali ad oras Lapponiae
rossicae et in mari albo, anno 1869-70.
Soc. Natur. St. Petersburg. 1870.
Loman, J. C. C. Decalopoda Eights oder Colossendeis Jarz.
Zool. Anz., Bd. XX VIII., 1905, pp. 722-3.

T. V. HODGSON.

20. Mermnert, F. Pyenogonida.

The Danish Ingolf Expedition, Vol. III., 1899, Pt. 1, pp. 1-71., Tab. 1-5, Copenhagen.
. Miers, B. J. Crustacea of Kerguelen Island (Pycnogonids, pp. 211-214.)
Phil. Trans. Lon., Vol. 168, 1879, pp. 200-214, pl. X.

22. Mosrus, K. Arktische and Subarktische Pantopoden.

Fauna Artica. Eine Zusammenstellung der arktischen Tierformen, mit besonderer Beriichsichtigung
des Spitzbergen Gebietes auf Grund der Ergebnisse der Deutschen Expedition in das Nordliche
Eismeer im Jahre 1898. Band IT., 1901, Lief. i, pp. 85-64.

3. Mésrus, K. Die Pantopoden der deutschen Tiefsee Expedition, 1898-99.

Wissenschaftliche Ergebnisse der deutschen Tiefsee Expedition auf dem Dampfer ‘ Valdivia,’
1898-99. Band 3, Lief. 6, 1902, pp. 175-196, Taf. XXIV.—-XXX.

. Prerrer, G. Zur Fauna von Siid Georgien.

Jahrb. d. Hamburgischen Wiss. Anst. Bd. VI., Heft II., 1889, pp. 41-49.

5. Sars, G.O. Pycnogonidea.

no
1

Zoology of the Norwegian North Atlantic Expedition. 1891.

. ScuimKeEwirscH, W. Sur les Pantopodes, recueillis par M. le lieutenant G. Cherchia pendant le
voyage de la Corvette ‘ Vettor Pisani’ en 1882-85.

Atti della R. Accad. dei Lincei, Mem. (4) VI., pp. 329-347, 1 pl. 1889.

7. SCHIMKEWITSCH, W. Compte-rendu sur les Pantopodes.

Reports on dredging operations... . U.S. Fish Comm. 8.8. ‘ Albatross,’ during 1891. Bull.
Mus. Comp. Zool., Vol. XXV., 1893, pp. 27-43, 2 pl.

. ScHrmKEWITScH, W. Ueber die Periodizitiit in dem System der Pantopoda.

Zool. Anz. Bd. XXX., 1906, pp. 1-22.

9. Stepping, T. R. R. The Nobodies: A Seafaring Family.

Knowledge, Vol. 25, 1902, chap. 4, pp. 185-9.

. Tuomson, G. M. On the New Zealand Pycnogonida, with Descriptions of New Species.
Trans. N.Z. Inst., Wellington, Vol. XVI., 1884, pp. 242-8, pl. 14-16.

. Wison, E. B. The Pycnogonida of New England and Adjacent Waters.

Rep. U.S. Fish Comm. for 1878, pt. VI., 1880, pp. 461-506, pls. 1-7.

32. Winson, E. B. Report on the Pyenogonida.

Reports on the Results of Dredging . . . . during 1880 by U.S. Coast Survey 8.8. ‘ Blake.’ Bull.
Mus. Comp. Zool., Harvard, Vol. VIII., 1881, pp. 289-256, pls. 1-5.

Fig. 1.—Phoxichilus australis.

Fra. 1.—Pallenopsis villosa. 9 x 3.
la.—Chela. x 18.
1b.—Oviger. x 10.
2.—Pallenopsis pilosa.
3.—Pallenopsis hiemalis. 9. Terminal joints of leg.
3a.—Specimen from Cape Wadworth. Terminal joints of legs.
PLATE III.
Fra. 1—Nymphon hiemale. ¢ X 2.
la.—Palp. x 14.
1b.— Oviger, five terminal joints. x 16.
Fie. 2.—Nymphon lanare. x 3.
2a—Palp. x 14.
2b.—Oviger, five terminal joints. x 13.
Fic. 3.—Nymphon adareanum. g X 8.
3a.—Palp. x 70.
3b.—Oviger, five terminal joints. x 80.
Fie. 4.—Nymphon frigidum. x 10.
3a.—Palp. x 56.
3b.—Oviger, five terminal joints. x 60.
PLATE IY.
Fra. 1.—Chetonymphon villosum. x 4.
la.—Palp. x 17.
1b.—Oviger, five terminal joints. x 17.
Fic. 2.—Chatonymphon biarticulatum. @ x 3.
2a—Palp. x 27.
2b.—Oviger. x 16.
Fic. 3.—Chetonymphon mendosum. 9 X 4.
3a.—-Palp. x 20.
3b.—Oviger. xX 32.
Fig. 4.—Cheetonymphon australe var. austrinorum. ¢ X

EXPLANATION OF THE PLATES.

2.—Pseudopallene australis.

PLATE I.
Oe Xe
) 3 Be
2a.—Oviger, five terminal joints. @ x 20.

2b.—Denticulate spine from tenth joint.
@. Oviger, five terminal joints.

3.—Pseudopallene cornigera.

3a.—Denticulate spine from eighth joint.
4,—Pallenopsis hiemalis.
4a.—Oviger, six terminal joints.

4a.—Palp.
4b.— Oviger.

x 14.
x ilo,

oy 3% Gh

PYCNOGONIDA.

«

PLATE II.

X 27.

Ds
oO

x 880.

xX 530.

x 12:

Se PA

@ Hoek. Oviger, five joints, terminal one missing.

x

x

12.

9

2

70 T. V. HODGSON.

PLATE YV.
Fic. 1.—Pentanymphon antarcticum.
Ja.—Palp. x 27.
1b.—Oviger. x 40.
1c.—Denticulate spine from eighth joint. 630

PLATE VI.
Tig. 1.—Leionymphon grande. 9 x 2.
la.—Oviger x 4.
1b.—Third leg, terminal joints. x 8.

1c.—Right oviger of immature specimen. x 4

1d.—Right oviger of immature specimen. x 4.
le.—Right oviger of immature specimen. x 10.
1f.—Right oviger of immature specimen. xX 10.

Fic. 2.—Leionymphon minus. x 2.
2a.—Oviger. 9 x 10.
2b.—Oviger. ¢ x 10.
2c.—Denticulate spine from joint of oviger. g X 265.

PLATE VII.

Fre. 1.—Leionymphon australe. 9? x 3.

la.—Oviger, five terminal joints. 9 x 30.

1b.—Oviger, five terminal joints. ¢ x 23.
Fic. 2.—Leionymphon spinosum. 9 X 2.

2a.—Palp, five terminal joints. x 20.

2b.—Oviger, five terminal joints. x 20.
Fic. 38.—Leionymphon glaciale. 9 x 1°5.

3a.—Palp, five terminal joints. x 11.

3b.—Oviger, six terminal joints. x 11.

PLATE VIII.
Fic. 1.—Austrodecus glaciale. 9 x 15.
la.—Lateral view of body without appendages. x 15.
1b.—Palp. x 56.
Fic. 2.—Austroraptus polaris. 9 x 5.
la.—Palp. x 40.
1b.—Oviger. x 31.
Fic. 3.—Rhynchothorax australis. x 15.
Palp. x 72.
Oviger. x 88.

PLATE IX.
_Fic. 1.—Colossendeis australis. 9 x 1.
la.— Oviger, four terminal joints. x 4.
1b.— Outlines of second coxa showing sexual aperture. 9
1c.—Ouitlines of second coxa showing sexual aperture.
Fra. 2.—Colossendeis glacialis. Palp, terminal joints. x 8.
2a.—Oviger, four terminal joints. x 8.
Fic. 3.—Colossendeis frigida. Oviger, four terminal joints. x 8.
3a.—Terminal claw of Oviger. x 265.
Fic. 4.—Colossendeis rugosa. Oviger, four terminal joints. x

io}

PYCNOGONIDA. (ial

PLATE X.
Colossendeis.

Fic. 1.—C. australis. Special spine from eighth joint of Oviger. Principal row. x 100.
2.—C. australis. Special spine from eighth joint of Oviger. Second row. x 100.
3.—C. glacialis. Special spine from eighth joint of Oviger. Much worn. x 265.
4.—C. glacialis. Seta from dorsal surface of ninth joint of Oviger. x 265.
5.—C. frigida. Special spine from tenth joint of Oviger. Principal row. x 265.
6.—C. frigida. Special spine from tenth joint of Oviger. Second row. X 265.
7.—C. rugosa. Special spine from tenth joint of Oviger. Principal row. X 266.

Nymphon.

Denticulate spines from tenth Joint of oviger.

Fig. 8.—N. hiemale. Xx 350.

9.—N. lanare. x 455.
10.—N. frigidum. x 645.

Cheetonymphon.

Denticulate spines from oviger.

Fre. 11.—C. villosum, seventh joint. x 438.

12.—C. biarticulatum, tenth joint. x 680.

13.—C. mendosum, tenth joint. x 410.

14.—C. australe, tenth joint. x 480.

15.—C. australe var. austrinorum, tenth joint. x 512.

Note—The magnifications of Messrs. West, Newman & Co.’s drawings are approximate only. The
drawings were made on squared paper, with the assistance of an eyepiece micrometer, and in many cases
have been reduced to fit the plates.

-I
bo

T. V. HODGSON.

INDEX.

Ammothea charcoti, 40, 41.
Ammothea clausit, 40.
Ammothea communis, 3.
Ammothea curculwo, 3.
Ammothea grandis, 40, 45.
Ammothea hoeki, 3.
Ammothea wilsoni, 3.
Anoplodactylus neglectus, 2.
Anoplodactylus petiolatus, 2.
Ascorhynchus glaber, 3.
Austrodecus glaciale, 3, 53.
Austroraptus polaris, 3, 54.
Chetonymphon australe, 2, 32.

Chatonymphon australe, var. austrinorum, 2, 35.

Chatonymphon biarticulatum, 2, 28.
Chetonymphon brevicaudatum, 2.
Chatonymphon mendosum, 2, 30.
Chetonymphon villosum, 2, 26.
Colossendeis australis, 3, 59.
Colossendeis frigida, 3, 63.
Colossendeis gigas, 3.

Colossendeis yigas leptorhynchus, 3.
Colossendeis glacialis, 3, 61.
Colossendeis gracilis, 3.
Colossendeis leptorhynchus, 3.
Colossendeis megalonyZz, 3.
Colossendeis robusta, 3.
Colossendeis rugosa, 3, 64.
Cordylochele turqueti, 9.
Decolopoda antarctica, 3.
Decolopoda australis, 1, 3.
Leionymphon australe, 3, 46.
Leionymphon clausu, 3.
Leionymphon gibbosum, 2.

Leionymphon glaciale, 3, 50.
Letonymphon grande, 2, 41.
Leionymphon minus, 2, 44.
Letonymphon spinosum, 8, 49.
Leionymphon striatum, 2.
Nymphon adareanum, 2, 23.
Nymphon antarcticum, 2.
Nymphon brachyrhynchum, 2.
Nymphon frigudum, 2, 25.
Nymphon fuscum, 2.
Nymphon gracile, 2.
Nymphon gracilipes, 2.
Nymphon hamatum, 2.
Nymphon hiemale, 2, 20.
Nymphon lanare, 2, 22.
Nymphon meridionale, 2.
Pallene dimorpha, 2.
Pallenopsis fluminensis, 2.
Pallenopsis glabra, 2, 11.
Pallenopsis hiemalis, 2, 17.
Pallenopsis patayonica, 2, 20.
Pallenopsis pilosa, 2, 15.
Pallenopsis villosa, 2, 13.

Pentanymphon antarcticum, 1, 2, 36.

Phovichilus australis, 2, 5.
Pseudopallene australis, 2, 10.
Pseudopallene cornigera, 2,7.
Pyenogonum magellanicum, 2.
Pycnogonum magnirostre, 2.

Rhynchothorax australis, 1, 3, 57.

Tanystylum chierchie, 3.
Tanystylum dohrnii, 3.
Tanystylum styligerum, 3.

a

en) ; ; West,Ne dcl.et Eth.
i Phoxehilus australis. 2.Pseudopallene australe. ee ee

3 Pseudopallene cornigera. 4. Pallenopsis hiemalis.

_

Plate Il _

5

_

: West, Newman. lith.
Pallenopsis.

iP anillosa. 2. P. pilosa. 3.P. hiemailis.

7 -
ad 7
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7
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Newman del.et lith.

:

West

Nymphon.

(Nie emule:
é.N.lanare.

3.N. adareanum.
4 WN steed om.

2
&
AY

West, Newman del et lith.

Chetonymphon.

2 C. biarticulatum.
4, C. avstPinorum.

ib (Cx wallliexsistaat
SG mencdosum,

“aI WEUIMS NT 4SS\A
TP uogxeg aT Buy

a

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cton ad nat.del.

West, Newman lith.

iy minus.

LeLemymphon.
2

i i gramde.

SS
asada seccaee Preto, YS

West, Newman delet lth.

Leionymphon.

_2.L.spinosum. 3. l.glaciale.

1. L.australe.

ey Nee | ai aie Plate VIIL.

: West, Newman del.et lith.
1.Austrodecus glaciale. 2. Austroraptus polaris. 3. Rhynchothorax australis.

7

West,Newmam lith.

4. C. rugosa.

3. C. frigida.

Colossendeis.

2. C. glacialis.

eC amstiealis.

Figs 8-15 West,Newman del.et lith.

apo nes ee australis. Figs 384.C.glacialis. Figs 5a6.C frigida. Mig.7. C. —
Fig.8. Nymphon hiemale. Fig.9. N.lanare. Fig 10. N.frigidum.

Te a. Chetionymphon villosum. Fig.12.C. biarticulatum. Fig.13. C.mendosum.
Figi4. C. australe. ig.15. C.austrinorum.

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