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‘Journal
OF THE
MARINE BIOLOGICAL ASSOCIATION
OF
THE UNITED KINGDOM.
VOLUME X (N.8.).
1913-15.
PLYMOUTH:
PUBLISHED BY THE ASSOCIATION.
Agents in London :—Messrs, Dutau & Co., Lrp., 37 Soho Square, W.
The Council of the Marine biological Association wish it to be
understood that they do not accept responsibility for the accuracy of
statements published in this Journal, excepting when those statements
are contained in an official report of the Council.
CONTENTS OF VOLUME X.
(NEW SERIES.)
List of Governors, Founders, and Members—
October, 1913 : Z 5
May, 1915 ,
Report of the Gesnoi”:
1912
1913
1914 F :
Balance Sheet, 1912
ditto 1913
ditto 1914
ALLEN, E. J.
On the Culture of the Plankton Diatom Thalassiosira gravida Cleve, in
Artificial Sea-water
Auten, E. J.
Polychzta of Plymouth and the South Devon Coast, including a List of
the Archiannelida
Bovuvirr, E.-L.
Recherches sur le Développement post-embryonnaire de la Langouste
commune (Palinurus vulgaris)
Bouvier, E.-L.
Observations nouvelles sur les Trachelifer, larves lucifériformes de Jaxea
nocturna
Bouvier, E.-L.
Quelques mots sur la variabilité du Pycnogonum littorale Strom.
CiaRk, R. 8.
General Report of the Larval and Post-Larval Teleosteans in Plymouth
Waters 5 :
CrawsHay, L. R.
Notes on Experiments in the Keeping of Plankton Animals under
Artificial Conditions
Crawsuay, L. R.
A Method of Separating Sponge Spicules by Filtration
De Morean, W., and the late G. H. Drew.
A Study of the Restitution Masses formed by the Dissociated Cells of the
Hydroids Antennularia ramosa and A. antennina : ;
Denby, ARTHUR.
On the Occurrence of Aphroceras (Leucandra) cliarensis Stephens, near
Plymouth : : : : : :
Fucus, H. M.
On F, Echinus Hybrids
GEMMILL, JAMES F,
Twin Gastrule and Bipinnariz of Luidia sarsi Diiben and Koren
Gray, J.
The Electrical Conductivity of Fertilized and Unfertilized Eggs
HarTMEYER, R.
On Alcyonium pulmonis instar lobatum Ellis
LeicH-SHarp, W. Harrop.
Calliobdella lophii Van Beneden and Hesse
MorteENsEN, TH.
On the Development of some British Echinoderms
lv CONTENTS OF VOLUME xX.
Nicouu, W.
The Trematode Parasites of Fishes from the English Channel
Orton, J. H.
The Ciliary Mechanisms of the Gill and the Mode of Feeding in
Amphioxus, Ascidians, and Solenomya togata ' ; :
Orton, J. H.
On some Plymouth Holothurians
Orton, J. H.
On the Breeding Habits of Echinus miliaris, with a Note on the Mecding
Habits of Patella vulgata .
Orton, J. H.
On Ciliary Mechanisms in Brachiopods and some Polyehae with a
Comparison of the Ciliary Mechanisms on the Gills of Molluses,
Protochordata, Brachiopods, and Cryptocephalous Polychetes, and
an Account of the Endostyle of Crepidula and its Allies
Orton, J. H.
Preliminary Account of a Contribution to an Evaluation of the Sea
Orton, J. H.
On a Hermaphrodite Specimen of Amphioxus, with Notes on Experi-
ments in Rearing Amphioxus :
Ramsay, L. N. G.
On Leptonereis glauca Clpde., and the Genus Leptonereis Kinberg
RrEEs, OLWEN M.
On Eloactis mazeli
Rees, OLWEN M.
Contributions to the Comparative Anatomy of some British Actinie
Rircutis, J.
Note on Two Unrecorded Plumularian Hydroids from the Plymouth
Area
Sexton, E. W.
On Anthura gracilis (Montagu)
Watton, Cuas. L.
The Shore Fauna of Cardigan Bay
Watton, Cuas. L.
The Distribution of some Littoral Trochide and Littorinide in Cardigan
Bay :
Watton, Cuas. L., and ius, Oxwan M.
Some Rare and Interesting Sea Anemones from Plymouth
ZIMMERMANN, K.
Habit and Habitat in the Galatheidea : a Study in Adaptation
Abstracts of Memoirs FUCORCIEE oes done at the iigicigenas
Laboratory .
List of Publications recording the Beeane of Raseteohed
carried out under the auspices of the Marine Biological
Association of the United Kingdom in their Laboratory
at Plymouth or on the North Sea Coast from 1886-1918 .
PAGE
466
19
211
254
143
On the Development of some British Echinoderms.
By
Dr. Th. Mortensen, Copenhagen.
With Figures 1-15 in the Text.
For several years I have felt the desire of going to Plymouth in order to
gain practical knowledge of the excellent methods for rearing pelagic
larvee of marine animals, which have been worked out there, especially
by the Director of the Marine Biological Laboratory, Dr. E. J. Allen.
I was therefore very glad to receive last year an invitation from Dr.
Allen to come and stay some time at his laboratory, and having got a
erant for this purpose from the Carlsberg Fund and from the Danish
Government, I had at length the desired opportunity.
The time I spent in Plymouth—from June 10th to July 15th this
summer (1913)—was long enough for learning the methods, but, unfortu-
nately, too short for having the full profit of my rearings, because several
of the larve take a longer time to reach their full size and still more to
pass through metamorphosis. However, the results attained are not
unimportant.
No less than six different species of Echinoderms were reared to a more
or less advanced stage of development, according to the date at which
fertilization could be undertaken, and according to the rate of growth of
the different larval forms. These six species are: Asterzas glacialis,
Luidia ciliaris, Ophiactis Balli, Ophiocoma nigra, Spatangus purpureus,
and Holothuria mgra. Fertilization of Echinocardium flavescens was also
undertaken, but unfortunately the whole culture was destroyed by an
accident, and no material was got later on of the species. Some other
forms, the development of which I wanted likewise to study, e.g. Echino-
cardium pennatifidum, Amphiura (Ophioenida) brachiata, Ophiopsila
aranea, were not ripe at that time or sufficient material could not be got.
The main purpose of these studies on the larval development of differ-
ent Echinoderms—which I hope to have the opportunity of continuing
during a planned voyage to the Pacific—is to find the characteristic
features of the larval forms and to see if the larvee have any bearing on the
NEW SERIES.—VOL. X. NO. 1. NOVEMBER, 1913.
2 DR. TH. MORTENSEN.
classification of the full-grown animals. The embryological development
in itself is not at present the object of my researches, and in the present
report, therefore, only occasionally pure embryological facts are given.
_As I had, of course, not much time to study the living larve more
closely, having so many different cultures going on at the same time, I
preserved material of the different developmental stages for study later
on. On examining the preserved larve after my return to Copenhagen
I found that a very regrettable mishap had occurred. The alcohol in
which the larvee were kept had in some way or other become acid, and
the skeleton of all the larvee had been dissolved. As the specific char-
acters are especially found in the skeleton in those larvee which are pro-
vided with such, the value of my material had thus been considerably
diminished. Fortunately I had made a preparation in Canada balsam
of the larva of Ophiactis Balli while still in Plymouth, so that in this case
nothing was lost.
After I left the laboratory my cultures were looked after for some time
by the attendant, Mr. Smith, and some of the later stages were sent me.
In this way I got the later stage of the Luidia larva; a few larvee of Spat-
angus purpureus, with the skeleton preserved, also came to hand, but in
so poor condition that only little use could be made of them. Of the
other larvee only a few of A. glacialis were obtained, but these were not
in a more advanced stage than that reached before I left the laboratory.
I.—Asterias glacialis.
The development of this species has never been satisfactorily worked
out, in spite of the fact that it is one of the objects commonly used in
experimental embryology. A. Russo, in his paper “Contribuzione all’
embriologia degli Echinodermi e sviluppo dell’ Asterias glacialis O. F.
Miiller,’* describes the first developmental stages, until the formation
of the vibratile chord. Having reached this stage the larve began to
degenerate. Some later stages, which were caught pelagically, were
also referred by Russo to this species (his figures 22-25) ; it 1s, however,
evident enough that they cannot belong to this species—the strong
development of the vibratile chord at the anterior end of the frontal (or
preoral) area, where the brachiolarian processes appear later on in the
Asterias larva, is sufficient proof that they cannot belong to an Asterias.
In my Kchinodermenlarven der Plankton Expedition (p. 30), I have
given the name Bipinnaria Russoi to this larva. The rearing of the more
advanced stages of the A. glacialis larva has given the definite proof that
* Boll. d. Soc. di Naturalisti in Napoli, Ser. 1, Vol. VII (1892).
ON THE DEVELOPMENT OF SOME BRITISH ECHINODERMS., 3
I was right then in maintaining that these later stages figured by Russo
could not belong to A. glaczalis.
The most important and interesting contribution to the development
of A. glacialis has been given by Yves Delage, who has reared partheno-
genetic larvee of this species to full size and beginning metamorphosis.*
In spite of this it is still very desirable to make further studies of
the normal development of this species. One can, of course, not be sure
beforehand that the parthenogenetic larve are quite like those normally
developed. Further, the figures given by Delage are partly not very
satisfactory. In fact, it still remains uncertain what the specific char-
acters of this larva are, by which it may be distinguished from other
Asterias larvee, or whether, perhaps, such characters do not exist, so
Fig. 1. Fig. 2.
Kies, 1-2.—Bipinnaria of Asterias glacialis, seven days old. 1, front view ;
2, side view ; ¢, enteroccel vesicle. 100/1.
that this larva could not be distinguished with certainty from other
Asterias larvee, for instance that of A. rubens.
I was very glad then to have the opportunity already on the second
day (the 12th June) after my arrival at the laboratory of making an arti-
ficial fertilization of A. glacialis. The fertilization was very successful,
about 95 per cent of the eggs being fertilized. The culture went on ex-
cellently, the larvee being fed with the diatom Netzschia from Dr. Allen’s
cultures. However, I did not succeed in obtaining the fully developed
larval form. Delage found that the rate of growth of his parthenogenetic
larvee was comparatively slow, and I had the same experience with the
normal larve.
The differentiation of the vibratile chord began after five days, and after
* Yves Delage, “ Elevage des larves parthénogénétiques d’ Asterias glacialis” (Arch. de
Zool., expér. et gén. (4), II, 1904, pp. 27-46.)
4 DR. TH. MORTENSEN,
seven days (the 19th) the stage represented in Figures 1-2 was reached.
For the next two weeks there was no further differentiation, and I nearly
gave up the hope of getting it to proceed in its development, thinking
that the diatoms were perhaps not suitable food for this larva; indeed,
I found that the diatoms ejected by it had the same colour as those
which had not been swallowed, so it appeared that the larve could not
digest the diatoms. But on the 4th July I found some specimens in
which the left enteroccel vesicle had begun to grow forwards, and now
the development went on continually. On the 7th July the enteroccel
E
y
‘
sta Sa
kd)
Paes ays
Cnr
\
ILA
ey ——
fr %
tial Serna SS
\ 4
Fig. 4.
Fics. 3-4.—Bipinnaria of Asterias glacialis, four weeks old.
4, side view. 80/1.
3, front view ;
vesicles had united in the preoral lobe, and the long processes had begun
to develop. The stage represented in Figures 3-4 was reached on the
9th July. When I left Plymouth, on the 15th, no essential advancement
beyond this stage could be observed, and a few jarve sent to me later on
were not in a more advanced stage either. I am thus unable to give
definite information of the specific characters of the fully developed larva.
Judging from the figures given by Delage, the larva of A. glacialis
differs from the larva of A. rubens and vulgaris, the only two other species
known to which it is similar, in the sucking disc at the basis of the
brachiolarian processes being surrounded by a complete ring of small
ON THE DEVELOPMENT OF SOME BRITISH ECHINODERMS. 5
papilla, while in the two other species there are only 2-3 papille at each
side of it (cp. text Figs. 4-6 of Delage’s paper). Also the crown of the
brachiolarian processes appears to afford a good specific character, there
being 2-3 circles of small papillee on a thickened ring, while in the other
species there is only a single circle of papille at the tip and no thickened
ring. If this proves to hold good for the normally developed larva of
A. glacialis, it will be easily distinguishable from the other species. A
number of larvee which were taken in the Plankton at Plymouth all had
only 2-3 papille at each side of the disc, and the crowns consisting of a
single circle of papille ; they should accordingly all belong to A. rubens,
which may be possible, since also some few ripe specimens of this species
were found. In any case, it is very desirable to have the A. glacialis
larva reared to its full size, so that we may be able to see, with certainty,
by which characters it differs from the A. rubens and A. vulgaris larve. As
the species A. glacialis is not so very closely related to the other two species
mentioned, one would expect the larve likewise to be distinct enough.
In the Echinodermenlarven der Plankton Expedition (p. 43), I have
distinguished, under the name of Bipinnaria levis, an Asterias larva
found by Joh. Miller at Elsinore, which differs from the A. rubens larva
in having no dorsal median process. I suggested that this larva might
belong to A. glacialis, as there are found only three Asterias species in
the Sound (between the Kattegat and Baltic), i.e. A. rubens, Miilleri and
glacialis, the latter being, however, very rare here. The larve reared by
Delage would seem to show that the dorsal median process is as well
developed in the Bipinnaria of A. glacialis as in those of A. rubens
and vulgaris, and then the B. levis can only be an abnormal larva of
A. rubens. I have never observed such specimens among the numerous
larvee of this species which I have seen.
The culture of the A. glacialis larvee showed the interesting feature
that a large number of the larve, about 50 per cent of them, had either
two dorsal pores, one for each enteroccel vesicle, or the vesicles were
united across the stomach, having one single, median pore (Figures 5-6),
This feature has also been observed by Goette* in the larva of the same
species. G. W. Field, in his paper “The Larva of Asterias vulgaris”
(pp. 110-111), describes the formation of two pore canals in the young
A. vulgaris larva as a normal feature, while the presence of two pore
canals has otherwise been regarded as pathological. Field found the two
* Goette, “Bemerkungen zur Entwicklungsgeschichte der Echinodermen” (Zool. An-
zeiger, 1880, p. 324. Fig. 2).
+ Quart. Journ. Micr. Sci., N.S., 34, 1893.
6 DR. TH. MORTENSEN,
pores persisting only a short time, the right bemg closed again 8-12
hours after its formation. Though I have not paid attention to this on
examining the living larve, I think I can say definitely that the forma-
tion of two pore canals is not a normal process in the larva of A. glacialis.
In the larvee which I preserved on the 16th June, at 9 p.m., the enterocee]
vesicles have not been formed; in those preserved on the 17th, 10 a.m.,
they are formed, and the left vesicle alone has a pore. It is certainly
very improbable that the pote of the right vesicle should then already
have disappeared completely; this process would in that case go much
faster than Field has found it in A. vulgaris. It seems to me that the
Fig. 5. Fig. 6.
Fies. 5-6.—Bipinnaria of Asterias glacialis, showing abnorma!] formation of
dorsal pores. Seen from the dorsal side. 100/1.
facts here produced rather tend to show that what Field has found is an
abnormality. In any case the two pores in the A. glaczalis larva repre-
sent an abnormality. To enter on a discussion of the possible phylo-
genetic importance of the two dorsal pores is not the place here.
I must also mention the observation that the larve of this species, as
well as of all the other species reared, in swimming rotate around their
longitudinal axis, always turning to the left. In the Spatangus and
Ophiactis larve this rotation ceases along with the development of the
long processes ; in the other larvee it had not ceased in the most advanced
stages observed.
IJ.—Luidia, ciliaris.
This species at first caused me a good deal of trouble. Both females
and males were found with ripe genital products, but the spermatozoa
did not move. Being myself not familiar with experimental work on
fertilization, I asked Mr. J. Gray, who was working at the laboratory,
ON THE DEVELOPMENT OF SOME BRITISH ECHINODERMS. i
for advice. He suggested that we might try to raise the alkalinity of the
water by adding some drops of sodium hydroxyde (NaOH). This proved
excellent. The spermatozoa at once began to move, and then the fertiliza-
tion succeeded completely. It was already at a rather late point of time,
the 27th June, so that it could not be expected to get the complete de-
velopment of this species ; still a good deal was reached, and as this is the
first time a Luidia has been reared, the observations are of some interest.
The cleavage is unequal, the relative size of the two first cleavage
cells being, however, somewhat variable. The blastula has the same
remarkable character as is described by Masterman for Henricia san-
guinolenta,* and by Gemmill for Solaster endeca,{ the cell layer forming
Fig. 9.
Fies. 7-9.—Bipinnaria of Luidia ciliaris. 7, five days old; 8, six days old;
9, eighteen days old. Front view. 100/1.
irregular folds. The gastrula is rather elongate and large; this stage
is reached on the third day. After five days the larve begin to assume
the shape of small Bipmnarie (Fig. 7); the enteroccel vesicles have
formed, but the vibratile chord is not yet differentiated at the anterior
end. The next day, the 3rd July, the vibratile chord was complete
(Fig. 8). The most advanced stage to which the larvee reached before I
left Plymouth is represented in Figure 9, from the 14th July. The
processes have begun to appear, and the preoral lobe has begun to assume
the characteristic elongate shape of the Luzdia larva; the enteroccel
vesicles have united in the preoral lobe.
After my return to Copenhagen I had the pleasure to receive a couple
* A. T. Masterman, “The early development of Cribre/la oculata (Forbes), with
remarks on Echinoderm development” (Z'rans. R. Soc. Edinburgh, Vol. XL, 1902). See
especially Plate 1, Fig. 17.
+ James F, Gemmill, “The development of the starfish Solaster endeca (Forbes)”
(Trans. Zool. Soc., London, XX, 1912).
8 DR. TH. MORTENSEN.
of larvee from the same culture, preserved by Mr. Smith, on the Ist August,
being thus a little over one month old. They are represented in Figures
10-11. Here the shape of the Luidia larva, so characteristic through
the elongated preoral part and the long median processes, is easily
recognized. The length of the larva is now 1 mm. Still the development
is not sufficiently advanced for showing definitely by which characters
Fig, 10. Fig. 11.
Fics. 10-11.—Bipinnaria of Lwidia ciliaris, five weeks old; 10, front view ;
11, side view. 100/1.
this larva is distinguished from the Bipinnaria of Luzdza sarsi. But it
can now scarcely be doubted that the larva figured by Garstang, in his
paper “ On some Bipinnarize from the English Channel,” * is really the
larva of L. ciliaris. This species is very common at Plymouth, while
L. sarsi is rare ; its breeding season is June to July, and Garstang found
the larva in August. I have previously held the opinion that Garstang’s
larva belonged to L. sarsi ;+ I must now join Ludwigt in the opinion
* Quart. Journ. Micr. Sci., N.S., 35, 1894.
+ Echinodermenlarven der Plankton Expedition (p. 40). Nordisches Plankton
Echinodermenlarven (p. 11).
ft H Ludwig, ‘Der Asteriden des Mittelmeeres.” Fauna u. Flora d. Golfes v.
Neapel, 24 Monogr., 1897 (p. 82).
ON THE DEVELOPMENT OF SOME BRITISH ECHINODERMS. 9
that it belongs to LZ. ciliaris. It is, however, still very desirable that
this larva should be reared to metamorphosis—and as it has now been
found to be easily reared, this will probably soon be done—this large,
beautiful larva must, indeed, be a magnificent object for embryological
study.
In the Echinodermenlarven der Plankton Expedition (pp. 39-40), I have
remarked, in connection with the suggestion made by Hensen that the
young larve might be fixed, that this conclusion is scarcely justified,
because the young larve have not yet been found. To this remark
Hensen has added the followmg note (p. 40): ‘‘ Meine Atusserung
lautet : ‘ Die I. Fahrt brachte 114, die IT. 11, und die III. 78 Luidien mit
Stern, in Summa 203, deren Diagnose wir Hrn. Mortensen verdanken.
Es miissen doch wohl die jiingeren Larven eine festsitzende Lebensweise
haben, sonst kénnten sie uns nicht entgangen sein.’ Da Zahlen beweisen,
b)
muss ich an diesem Satz festhalten.’”’ Though I have always been quite
convinced that the Lwidia larva could not have a fixed stage before the
free-swimming larval stage, it is quite satisfactory for me that I have
now been able to give the definite proof that my opinion, founded on
morphological grounds, was right, in spite of Hensen’s statistics. To
be sure, my observations are made on L. ciliaris, while Hensen speaks
of L. sarsi: but to suppose that of two so very similar larve one
should be fixed in its first stages, the other free-swimming, would really
be too absurd.
It is very remarkable that the larve of L. ciliaris appear to be com-
paratively rare at Plymouth. Being impressed with the enormous
development of the gonads in this species I have tried to make an approxi-
mate calculation of the number of eggs ina large L. ciliaris. In a specimen
of 30 cm. arm length I counted the number of gonads—which are here
arranged in a series along each side almost to the point of the arm in-
stead of one large gonad at each side of the basis of the arm as is the rule
in Asteroids—and found them to number 150 in each series—300 per arm.
As the species is seven-rayed, a complete* female of that size, which is
nearly the average, has 2,100 ovaries; these are, however, of some-
what different size, decreasing in size towards the point of the arm.
An ovary from about the middle of the arm was divided into a
hundred parts of as nearly as possible equal size, and the number
of eggs in one part was counted; it was ca. 3,000. This means
that in one ovary there are at least ca. 300,000 eggs, probably nearer
* The arms very easily break off, and it is quite difficult to get complete specimens,
though such are often seen in the contents of the trawl, before it is hauled on deck.
10 DR. TH. MORTENSEN,
half a million. Taking, however, into consideration the decreasing
size of the ovaries towards the point of the arm it may be just to
take as the mean number of eggs per ovary only 100,000, and
for safety we may still reduce the number of ovaries to 2,000. This gives
as the number of eggs in a grown female of L. cilzarzs no less than 200
millions. We might expect from this that this species would be exceed-
ingly common, the larve as well as the grown. But the larve are only
rarely observed, and as for the grown specimens, one may certainly
expect to get about half a dozen specimens in each haul with the trawl,
and from their large size this makes the impression of a good lot—in
Fig. 12.
Fic. 12.—Female Luidia ciliaris, opened so as to show the genital organs. 4 of natural
size. (From a photograph by Mr. F. Martin Duncan.)
reality this is a very small number, especially compared with Ophiocoma
and Ophiothriz, which are generally taken by thousands in each haul.
What a waste of eggs must here take place !
In Figure 12 is represented a female of L. ciliaris opened so as to show
the gonads. It gives, however, only a slight impression of the profusion
of gonads seen in such a specimen, the more conspicuous on account of
the beautiful red colour of the gonads with the ripe eggs.
I may here mention that in this species a distinct sexual dimorphism
may be observed, at least in the breeding season. The colour of the
ON THE DEVELOPMENT OF SOME BRITISH ECHINODERMS, 11
female is red, that of the male brownish; the rays of the female are
somewhat broader than in the male, and upon the whole the male scarcely
reaches so considerable a size as the female. It is mostly quite easy
to distinguish between the sexes at a glance—quite apart from the fact
that generally the arms break so as to expose some of the gonads.
In the stomach of this species I have found remnants of Ophiurids
(Ophiothriz).
Ill.—Ophiactis Balli.
On the 17th June several specimens of this species were taken on the
Eddystone grounds, especially on tubes of Chetopterus and on Ascidians.
Some of these were found to contain ripe sexual products; they were
placed in a large jar with only a few centimetres of water, in order to try
if they would shed their eggs and sperm. Already next day I had the
pleasure of finding the fertilized eggs, which had partly already reached
the blastula stage ; at 12 o’clock, viz. after scarcely more than eighteen
hours, the first swimming blastule were observed. On the 19th the
embryos were found swimming actively close to the surface of the water ;
they were somewhat elongated, a little transparent at one end. On the
20th the first rudiments of the skeleton were formed, and the postero-
lateral processes had begun to appear, showing already an indication of
red colour at the point. On the 21st the larve had already distinctly
the shape of an Ophiopluteus ; the antero-lateral and the postoral rods
(and processes) had begun to grow out, and likewise the recurrent rod
had begun to appear. On the 26th the body skeleton was completely
formed, and the three pairs of processes had become somewhat longer,
especially the postero-lateral. These latter processes are distinctly red
at the point ; also the postoral transverse chord has a reddish tint, the
larva being otherwise uncoloured. It always swims near the surface,
but at this stage does not any longer rotate round its longitudinal axis.
Having reached this stage the development ceased; the larve still
remained alive for some days, but without showing further advance.
Probably the diatoms were not suitable food for them. However, the
stage reached is sufficiently advanced for showing the characters of the
larva, so that it will be possible to recognize it also in later stages, the
essential characters of the Ophioplutei lying in the body-skeleton, which
had, fortunately, already reached its full development (Fig. 13).
The main features of it are the following : Recurrent rods are present,
whereby two large meshes are formed in each half of the body. The
cross-rods are peculiar in being slightly lobed at the end, the lobes of the
two rods of each side catching into each other. The end-rods are rather
12 DR. TH. MORTENSEN.
long, straight, trifid at the point. The postero-lateral rods are provided
with thorns along the inner side, and also the antero-lateral rods are
slightly thorny. (These thorns will doubtless be considerably more.
numerous in the fully developed larva.) It must be pointed out that there
is no posterior tuft of cilia; the frontal area is quite small. Other-
wise there is nothing to be remarked concerning the shape of the larva,
Fig. 13.
Fic. 13.—Skeleton of the Ophiopluteus of Ophiactis Balli. cr, cross-rod ; e, end-rod ;
r, recurrent rod. 275/1.
in this stage at least ; it has the typical Ophiopluteus shape, as appears:
from the shape of the skeleton.
It is very satisfactory that the larva of this species could be reared to.
a sufficiently advanced stage for recognition, this being the first informa-.
tion of the larval form of a species of the genus Ophiactis. (The two
species Ophiactis Kroyert (L.) and O. asperula (Phil.) appear to be vivi-
parous.*)
IV.—Ophiocoma nigra.
It was not until towards the end of June that this species was found to-
contain ripe sexual products. On the 25th June some specimens were
put in a jar in the same way as Ophiactis, and the next day some fertil-
ized eggs were found. It was no large number, and I then repeated the
experiment, but without success, evidently because the specimens were
* H. Ludwig, ‘‘ Brutpflege bei Echinodermen.”” Zool. Jahrbiicher, Suppl. VII, 1904,.
p. 693.
ON THE DEVELOPMENT OF SOME BRITISH ECHINODERMS. 13
not very ripe. To open the specimens and take out the eggs did not
prove good either for the same reason. However, some results were
obtained from the eggs got at the first experiment. The development
proved to be comparatively slow. The first indication of the postero-
lateral processes was found on the 30th, i.e. in ca. five days old embryos.
The embryos are remarkably elongate, and the oral lobe remains very
large after the formation of the said processes. On the Ist July I found
the first rudiments of the skeleton. On the 4th July there was seen the
first indication of the postoral rod, and the postero-lateral processes had
somewhat increased in length—but herewith the development apparently
ceased ; the larvee were alive and apparently healthy when I left on the
15th July, but the development was not advanced beyond the stage
reached on the 4th. Probably again the food was not suitable.
The development reached a sufficiently advanced stage to show that
the body skeleton is simple, without recurrent rod. The cross-rods are
thorny. The body skeleton is upon the whole small, the rods short.
Unfortunately I can give no figure of it, the skeleton having been dis-
solved in all the preserved specimens as explained above. The colour is
yellow, or at the point of the postero-lateral processes, yellowish green :
there is no indication of red pigment.
Though the rearing of this larva was thus not very successful, the
results obtained are not without value ; from the indications given here
it will doubtless be possible to recognize the Ophiocoma larva, when it 1s
found in the plankton. The two Ophiurids, Ophiothrix fragilis and
Ophiocoma nigra, are by far the most numerous Ophiurids occurring at
Plymouth ; they must almost cover the bottom on large areas. The
larve of both forms must occur in large numbers in the full breeding
seasons of the two species. As the larva of Ophiothrix is well known, it
must be possible to find out, with the help of the indications given here,
which larva belongs to Ophiocoma, and in all probability the larva is
already known. Ina paper on Loch Sween (“ The Glasgow Naturalist,”
Journ. Nat. Hist. Soc. of Glasgow, IV, 1912) Professor J. Graham Kerr
has figured (p. 48, Fig. 4) a very peculiar Ophiurid larva, which agrees
with the Ophiocoma larva in having a simple body skeleton and a very
large preoral lobe. It occurred in immense numbers at the beginning of
August—the season thus being likewise in accordance with the sugges-
tion that it is the Ophiocoma larva. In fact, Graham Kerr himself gives
that suggestion, and I think it very probable that he is right. The most
conspicuous peculiarity of this larva is the development of four “ epau-
lettes,’’ as I have previously found in a larva from the Bermudas de-
14 DR. TH. MORTENSEN.
scribed as Ophiopluteus Henseni in the Echinodermenlarven der Plankton
Expedition (p. 62, Pl. VII, 2). The occurrence of a similar—though quite
distinct—larva at the Bermudas is not at all against the supposition
that the larva figured by Kerr belongs to O. nigra, since this genus is
also represented at the Bermudas (by the species Ophiocoma echinata
(Lmk.) and O. pumila (Ltk.).
This larva has also been observed at Port Erm by Dr. H. C. Chadwick,
who showed me on my visit there (at the end of July) figures he had made
of these and many other Echinoderm larve. May we hope that he will
soon publish his many beautiful figures and interesting observations on
the Echinoderm larve ? They would doubtless prove of great value to
students of these larvee, which are so interesting from both a morpho-
logical and a biological point of view. Even if the larve can at present
only partly be referred to species, they are, at least most of them, so
well characterized that they can be recognized with certainty, and the
observations made on the larvee of hitherto unknown origin are by no
means lost, but may be directly transferred to the species to which
some such larve are later on proved to belong.
V.—Spatangus purpureus.
This species is one of the very first Echinoderms of which artificial
fertilization and rearing of the larvee were undertaken. It was A. Krohn
who did so in Messina in 1853 (‘‘ Uber die Larve von Spatangus pur-
pureus,’ Miill. Arch., 1853, p. 253, Taf. VII). He did not succeed in
rearing 1t to metamorphosis, but still so far that he thought he was
able to recognize it in free-swimming specimens. In another paper,
“ Beobachtungen iiber Echinodermenlarven”’ (2bid., 1854, p. 208), he
gave them some further observations on the structure of this larva, from
which it appears that it is characterized especially by the postoral,
postero-dorsal, and posterior rods being fenestrated only in their outer
part, a considerable portion at their basis remaining unfenestrated ;
further the postero-lateral processes (‘‘ auricularfortsatze ”) are “aus-
serst kurz, breit und abgerundet.”” In my Echinodermenlarven der Plank-
ton Expedition, as well as in Nordisches Plankton I have accordingly given
these characters for this larva, no later observations having been made
on it. The observations of Krohn are, however, not very detailed, and
especially it is an important objection that the reared larve did not reach
a very advanced stage. There must be several other Spatangoid larve
in the Mediterranean, and as their specific characters are not sufficiently
known we have no guarantee that the pelagic larve which Krohn re-
ON THE DEVELOPMENT OF SOME BRITISH ECHINODERMS, 15
ferred to Spatangus purpureus did really belong to that species. It was
therefore very satisfactory to me to get the opportunity of rearing the
larva of this species during my stay in Plymouth. It proved to be very
easy to rear; the larve developed normally and reached their full size
in the course of three weeks. The fertilization was made on the 23rd
June ; on the 14th July the larvee had all their processes developed, and
the first sign of the metamorphosis (formation of the oral disc) had
appeared. Unfortunately I cannot utilize this culture for a complete
description of the larval skeleton, on account of the mishap explained
above. Still some notes can be given which may prove sufficient for
the certain recognition of the larva.
The shape of the fully formed larva is, as shown in Figure 14, that of
the typical Spatangoid larva. It is especially to be noticed that the
postero-lateral processes are long and slender (and a little posteriorly
directed) as in other Spatangoid larve, not short, broad, and rounded as
stated by Krohn. If it is, upon the whole, really the S. purpureus larva
which Krohn has observed, it must then have been in a stage where the
postero-lateral processes are just about to appear. According to his
description, ““ Beobachtungen iiber Echinod. larven,” p. 209, quoted in
Echinodermenlarven der Plankton Expedition, the body shape of the larva
is rather complicated, with lobes and folds; in reality it 1s quite simple,
without folds, as seen in the figure. It is, then, most probable that the
larva described here by Krohn is not at all the S. purpureus larva, but
the larva of another Mediterranean Spatangoid—which species cannot be
ascertained at present. The only thing in the description of Krohn
which agrees with the S. purpureus larva is the extraordinary length of the
postoral, postero-dorsal, and, especially, the posterior processes. Very
probably also the other processes will attain a greater length than shown
in the figure. They are a little swollen at the point, which is conspicu-
ously coloured with red pigment.
a wave-like motion which begins at the attached end. Particles may in-
deed be observed to rest on these cilia for some time, but such particles are
eventually worked towards the lateral sets of cilia, which soon transport
them to the gill-bars. In the passage of the particles from the median
to the lateral cilia on the endostyle one can often make out that the
particles have become embedded in mucus. It is therefore doubtless the
function of the median cilia on the endostyle to pass on mucus secreted
by the endostyle to the lateral endostyle cilia and thence to the gill-bars.
This mucus, along with that doubtless secreted also by the pharyngeal
epithelium of the gill-bars, serves to entrap food-particles and render the
transportation of these easier.
Between the median and lateral sets of cilia on the endostyle a narrow
ciliated groove can be made out on either side (see Fig. 3). Particles are
frequently caught in these grooves, but they can be seen to be passed
quickly on to the lateral endostyle cilia and generally on to those portions
of the endostyle overlying a primary bar, and thence to the gill-bars.
Before passing on to a recapitulation of the’ ciliary mechanisms and
their function in Amphioxus, it will be convenient to examine the ciliary
arrangements so well known in the anterior end of the animal, namely
those in the buccal cavity, the wheel organ, and Hatchek’s pit, and the
peri-pharyngeal bands.
THE FUNCTION OF THE WHEEL ORGAN, AND THE
PERI-PHARYNGEAL BANDS IN AMPHIOXUS.*
The action of these organs can be made out by examining the anterior
end of the living animal through a microscope while it is feeding. During
the act of feeding the buccal tentacles are kept folded over one another.
In this way these tentacles act as a sieve, allowing only the finer suspended
particles to pass on into the buccal cavity. The efficiency of the buccal
tentacles in straining, when held in this manner, is increased by the
presence along the sides of the tentacles of conical papillee which sub-
divide the spaces between the tentacles, as is shown in Fig. 5. In this
manner the larger particles carried along in the ingoing current become
arrested on the buccal tentacles, only the finer particles being allowed to
pass onwards. A selection of the finer food-particles is thus effected.
From the buccal tentacles the main current with the suspended
particles passes through the buccal cavity, the mouth and onwards into
the pharynx.
In the buccal cavity, however, some particles fall out of the main
stream as a result of the occurrence of slack waters in the periphery of
* See Appendix on page 45 for an account of Andrew’s work on feeding in Amphioxus.
26 J. H. ORTON.
this region, and become drawn against the wall of this cavity by the
sets of cilia which are known collectively as the wheel organ. These sets
of cilia are shown on the wall of the buccal cavity in Fig. 5. They are
really ciliated grooves running antero-posteriorly in the posterior part
of the buccal cavity. Around the mouth these paths are connected
together by a circular ciliated path, which is stated by V. Wijhe (4) to be
INGOING CURRENT
Fic. 5.—View of the anterior end of a living Amphioxus (drawn as seen through a micro-
scope, x ca. 27), after keeping the animal in a dilute solution of methylene
blue in water. This view shows the action of the buccal tentacles in sieving off
the coarser food-particles at the entrance to the buccal cavity, the action of
the ciliated grooves (the Wheel Organ) in the wall of the buccal cavity, and the
collection of food-particles from this region of the body into the peri-pharyngeal
bands.
b.c. Buccal cavity.
hp. gr. Dorsal or hyperpharyngeal groove.
p-b. Peri-pharyngeal band.
v.t. Velar tentacles.
EN. Region of the endostyle.
The arrows in the buccal cavity lie alongside the ciliated grooves, along which
food-particles are lashed towards the mouth in the direction indicated by the
arrows. The large arrow passing through the mouth from the buccal cavity into
the pharynx indicates the course of the main stream.
sometimes complete and sometimes incomplete. These ciliated paths
have been said to be “ an organ for creating currents in the mouth back
to the pharynx.” There can be little doubt about their function, however,
if they are watched while the animal is feeding. As particles drop out of
the main current in the buccal cavity they very quickly become caught
in the anterior end of one or other of these ciliated paths and rapidly
whirled along the groove towards the mouth, becoming rolled into a
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. 27
mass with mucus on the way. A large number of these minor food-masses,
however, are swept into the main stream as they approach the oral
aperture and pass onwards into the pharynx. Some particles, however,
appear to pass between and sometimes along the velar tentacles on to the
internal surface of the pharynx, whence they are passed on to the peri-
pharyngeal grooves. It is well known that there are no gill openings
anterior to the peri-pharyngeal grooves. Thus the part of the pharynx
anterior to the peri-pharyngeal grooves serves as a collecting ground forthe
food-particles which have been caught in the buccal cavity. Most of the
particles, however, appear to pass around the ventral part of the mouth
to the peri-pharyngeal groove; while others appear to pass dorsally
straight into the dorsal groove. There is also, however, a steady dribble
of particles into the peri-pharyngeal groove from a position immediately
ventral to it. These particles are probably collected from the extreme
anterior portion of the endostyle, by which they are ejected in the same
way as we have seen at other parts. Doubtless these minor streams have
been the cause of the erroneous views which are current on the mode of
feeding in Amphioxus. _ If a little methylene blue is added to the water
from which an Amphioxus is feeding the edges of the ciliated paths in
the buccal cavity stain blue, which doubtless indicates the presence of
mucus glands at these points (see Fig. 5). The anterior end of each
ciliated groove can now be easily seen to form a pit-like depression around
which the cilia are lashing vigorously. As particles are caught by the
cilia they are seen to be passed along in the middle of the groove towards
the mouth, as has been described above.*
RECAPITULATION OF THE ACCOUNT OF THE FOOD
AND RESPIRATORY CURRENTS IN AMPHIOXUS.
The main food and respiratory current in Amphioxus is produced by the
lashing of the lateral rows of cilia on the gill-bars or gill-filaments (see
Fig. 4, l.c., Fig. 3, and Fig. 6). These lateral cilia lash across the length
of the filament from the cavity of the pharynx to that of the atrium.
In the adult Amphioxus there are about 180 gill-filaments on each side of
the body (Willey, 1. p. 17). Each of these carries two long rows of lateral
cilia, hence in all there are about 720 rows of long cilia acting like oars
lashing water through the body of the animal. These are indeed powerful
enough to produce the strong current that is to be observed.
* Tf a stronger solution of methylene blue is used the whole of the wheel organ as
well as the pharynx stains a deep blue, and a surprising amount of detail can be made
‘out over the whole of the body.
28 J. H. ORTON.
The main cilia which collect and transport the food-particles are those _
on the pharyngeal surface of the gill-filaments, namely, the frontal cilia.
(see Figs. 4 and 6, f.c., and Fig. 3). These cilia lash in a direction which is
chiefly along the length of the bars, but actually at an angle to the bars
in a ventro-dorsal direction (see the arrows on the right side of Fig. 3).
The gill-bars, it is to be remembered, run in the living animal in an antero-
dorsal to postero-ventral course, as is shown in Figs. 1, 2, and 3. Food-
collection is effected in the following manner. Mucus is secreted by the:
endostyle and passed on to the gill-bars in a thin sheet by the cilia on the
lateral portions of the endostyle. Probably mucus is secreted also by the
pharyngeal epithelium of the gill-bars. Food-particles are drawn against
the gill-filaments by the lateral cilia on those filaments, as we have already
seen; the particles become entangled in the mucus in which they are
hurried along the face of the gill-bars into the dorsal groove by the
frontal or pharyngeal cilia. The actions of these different mechanisms
are depicted in the accompanying diagram, Fig. 6.
It is thus evident that feeding in Amphioxus occurs automatically as.
in the Lamellibranchs. Amphioxus, however, has an advantage over
most Lamellibranchs in being able to swim away from a region where
the water is laden with innutritious or undesirable particles. And,
indeed, the occurrence of Amphioxus mainly on shelly or gravelly
grounds may be due largely to the desire of the animal to seek out.
grounds where the water is relatively free from undesirable, Le.
innutritiovs particles.
A food-collection of minor importance is also effected, as we have seen,
in the buccal cavity. Food-particles are collected into the ciliated grooves
on the wall of this cavity and transported in mucus through the mouth
to the peri-pharyngeal bands, often, however, these particles are drawn
into the pharynx in the main stream at the oral aperture.
These ciliated grooves in the buccal cavity doubtless lend some small
aid to the lateral cilia of the gill-filaments in producing the main current,
as probably also do the ab-frontal cilia of the filaments. Short cilia have
also been observed on the atrial epithelium overlying the gonads.
These cilia lash ventrally, and thus help somewhat in producing the-
main current.
THE FUNCTION OF THE PHARYNX IN AMPHIOXUS.
It is generally stated that the gill of Amphioxus functions mainly as a
respiratory and only secondarily as a feeding organ. In the light of the
present researches, however, it would appear that the pharynx functions.
At.
Fic. 6.—Diagram of a transverse section
of the pharynx and atrium of Amphioxus
to show the ciliary mechanisms on the gill,
which produce the main current and collect
and transport food-particles. (This diagram
serves equally well also for Ascidians.)
Ph. Pharynx, in the walls of which are
shown several gill-bars.
At. Atrium.
En. Endostyle, the lateral cilia of which
pass on mucus and food-particles from the
median cilia to the gill-bars.
D.Gr.
fie:
Dorsal groove of pharynx.
Lateral cilia on the gill-bars.
{
|
EN:
These produce the main current which
passes across the gill from the pharynx to
the atrium in the direction indicated by
the large arrows which cross the gill-bars
about the middle of the figure. (These
cilia should have been denoted in the
figure by the letters l.c.)
f.c. Frontal or pharyngeal cilia. These
cilia are the chief collectors and trans-
porters of food-particles, which become
caught in the mucus passed on to the
gill from the endostyle. The captured
food-particles are transported towards and
into the dorsal groove, as indicated by the
arrows along the inside of the gill-bars.
30 J. H. ORTON.
mainly as a water pump and a feeding organ, and it may indeed be
doubted whether on the whole oxygenation of the blood occurs in the gill
at all. On the other hand, the expenditure of such a large amount of
energy as is necessary to produce the main and food currents may well
leave the blood as it issues from the gill in a less pure condition than that
in which it entered. Moreover, it is to be remembered that the gill-fila-
ments of Amphioxus are very compact organs in which only the coelomic
blood-vessel lies at all near the surface (see Benham, 15, Pl. 6).
It would therefore seem more probable that oxygenation of the blood in
Amphioxus takes place in the relatively vast coelomic spaces adjacent
to the atrium, as, for instance, the endostylar coelomic canal in which
is contained the branchial artery, and the various coelomic spaces in the
dorsal regions of the atrium. Thus it is highly probable that the gill of
Amphioxus, like that of Lamellibranchs (see later, pp. 44 and 45), is
mainly a feeding organ and a water pump.
THE MODE OF FEEDING IN ASCIDIANS.
The similarity in general structure in the gills of Amphioxus and
Ascidians renders the mode of feeding in the Ascidians a matter of much
interest in comparison with that of Amphioxus.
The mode of food-collection in Ascidians has been investigated by
many zoologists, and correctly described by Fol (17) in various Ascidians,
and later by Roule (8, pp. 66, 67) in Ciona. It is curious that English
writers, including Willey (1, p. 185) and Herdman (9, pp. 15 and 16, p. 46),
describe the process differently, apparently accepting the earlier work of
Fol (4, 1872). Fol, in a summary of his later work (17, p. 240), states
that ‘‘Die Rinne (the endostyle) ist kein Ernaihrungs-abschnitt des
Kiemenkorbes sondern ein Driisenorgan. Die Nahrungsaufnahme
findet gleichzeitig mit der Athmung im ganzen Kiemenkorbe statt.”
Roule describing this process in Ciona states: ‘“Un mucus, sécrété
par le raphé ventral, est déversé en fins filaments sur la face interne
de la paroi branchiale ; 14, ces filaments agelutinent tous les petits cor-
puscules, amenés par l’eau, qui passent a leur portée ; puis, entrainés par
les mouvements des cils vibratiles des papilles, ils se dirigent obliquement
en haut et en arriére, de telle sorte que les filaments les plus antérieurs
se rassemblent en une seule masse qui suit le raphé dorsal pour pénétrer
dans la bouche cesophagienne, tandis que les postérieurs y parviennent
directement.’ On the other hand, English writers describe food-collection
as occurring in the endostyle and peri-pharyngeal grooves; the former
groove conducting mucus with contained particles forwards to the latter,
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS., 31
which in turn carries the food-mass upwards into the dorsal groove, and
at the same time assists in capturing food-particles. Delage and Herouard
(3, p. 144) point out the differences in the descriptions of this process, and
cautiously give only a general account.
FOOD-COLLECTION IN VARIOUS ASCIDIANS.
Observations have been made on a number of Ascidians, namely,
Ascidiella aspersa, Phallusia mamullata, Ascidia mentula and virginea,
Ciona intestinalis, Clavellina lepadiformis, Leptoclinum (Diplosoma)
gelatinosum and a species of Morchellium, with the result that the
process of food-collection has been found to be the same in all these
animals as that described by Fol and Roule.
When carmine particles are added to the water in which one of these
animals is living, for example, Ascidia mentula, the particles may be
observed with a hand lens to be drawn into the branchial cavity and
against the wall of the gill. Particles approaching the endostyle, however,
are seen to be immediately lashed out of this groove on to the wall of the
pharynx, just as is the case in Amphioxus. These particles become rolled
into a mass with mucus, and are transported across the branchial sac to
the dorsal lamina. All the particles entering the endostyle are washed
out on to the pharynx in this way, and no mass of collected food has
ever been seen—in any of the animals examined—to be passed forwards
along the endostyle. An examination of the endostyle through a micro-
scope shows further that the lateral rows of cilia on this organ lash in a
direction across the endostyle, and from the endostyle on to the pharynx,
and no transference of food-particles along the endostyle is seen. The
food-particles drawn against the pharynx become caught in mucus and
gradually transferred across the wall of the pharynx to the dorsal lamina,
becoming rolled into cylindrical masses with mucus on the way. This
process of food-collection and transportation is very well seen in the
Compound Ascidian Leptoclinum (Diplosoma) gelatinosum, as shown in
Fig. 7, which is a drawing of one living zooid in the act of feeding. In
such a small animal as this one is able to keep the whole animal in the
field of a microscope, and so to follow the course of even small food-
particles in the pharynx. The particles entering the branchial cavity
sometimes fall on to the pharyngeal wall close to the peri-pharyngeal
grooves, but in none of the animals examined have the particles posterior
to the grooves been observed to be drawn into these grooves. On the
contrary, in Ascidiella aspersa especially these food-particles become
collected in masses some distance posterior to the peri-pharyngeal groove
D2 J. H. ORTON.
as though the cilia in this region were lashing away from the groove.
The particles falling on to the region between the buccal tentacles and the
peri-pharyngeal grooves, however, are washed into these grooves by cilia
in a manner somewhat similar to that observed in Amphioxus.
At. OP
Fic. 7.—View of one entire zooid of the compound Ascidian, Leptoclinum gelatinosum,
to show the currents produced by the ciliary mechanism on the gill and the mode
of food-collection.
(Drawn from the living animal seen through the microscope, x about 60.) The
large arrows indicate the direction of the main current, and the dotted ones the
course of food-particles which have been captured and are being transported to
the dorsal lamina. Only the gill slits on the upper surface are shown.
A. Arrow indicating the direction of the inhalent current produced by the
lateral cilia, l.c.
lc. Lateral cilia on the sides of the gill slits: these produce the main current
by lashing from the pharynx towards the atrium.
B. Arrows indicating the current passing through the gill slits into the atrium.
C. Dotted arrows indicating the paths of the food-particles, as at M, captured
in mucus and travelling away from the endostyle towards the dorsal
lamina, DL.
DL. Dorsal lamina filled with collected food-particles seen through the wall of
the transparent pharynx.
En. Endostyle.
M. Food-particles embedded in mucus being transported by the frontal cilia
on the gill towards the dorsal lamina.
124 Pigment spots scattered about the surface of the colony.
At. Common atrium of the colony.
P.b. Peri-pharyngeal band.
When Leptoclinum (Diplosoma) is fed with a large amount of carmine
particles the process of feeding occurs extremely rapidly. Within a few
seconds from adding particles to the water the dorsal lamina becomes full
of the particles embedded in mucus ready to be passed into the cesophagus.
Clavellina can be observed through the microscope to feed in the same
way, and almost as rapidly as Leptoclinum. Ascidiella and Ciona feed
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. 33
more quickly than the other simple forms, which feed relatively slowly.
The process of food-collection at the anterior end of the pharynx in
Ascidia mentula is shown in Fig. 8. At the posterior end of the pharynx
in this animal the cilia in the dorsal groove lash food-particles forwards
to the cesophageal opening. This process can be easily observed by
cutting from the test a window, through which the processes can be
followed distinctly.
Fic. 8.—A view of the anterior end of Ascidia mentula to show the mode of feeding.
Drawn from the living animal, as seen through a hand-lens. A part of the pharynx
is drawn as though the test were transparent. (x ca. 4.)
A. Arrow indicating the direction of the inhalent current.
B. Arrow indicating the direction of the exhalent current.
At. Arrow in the atrium showing the direction of the main current after passing
through the gill slits.
En. Endostyle.
D.L. Locus of the dorsal lamina.
F.M. Food-particles collected into a cylindrical mass with mucus being trans-
ported across the gill-bars and away from the endostyle towards the
dorsal lamina, as indicated by the dotted arrows alongside.
G. One of the longitudinal bars of the gill.
CILIARY MECHANISMS ON THE GILL OF ASCIDIANS.
The main current through the branchial cavity of all the Ascidians
examined is produced by the lashings of the cilia on the sides of the gill-
bars, as has been observed by Herdman for Ascidia mentula (10, p. 47).
Food-collection is effected by the cilia on the pharyngeal surface of the
NEW SERIES.—VOL. X. NO. 1. NOVEMBER, 1918. c
34 J. H. ORTON.
gill-bars and the cilia on the papille on the bars. These cilia lash across
the length of the pharynx from the endostyle towards the dorsal lamina,
but are not specially active nor specially powerful in the simple
Ascidians, and food-collection is accelerated by the waving of the
longitudinal bars in a transverse direction. In this way the food
masses are pushed on as well as lashed onwards towards the dorsal groove.
The papille of the gill-bars thus assist in food-collection, and in those
animals in which they point towards the dorsal lamina, as in Ascidia
mentula, act somewhat like the bristles of a brush in pushing food masses
onwards. In Ascidia mentula cilia have been observed on the atrial
surface of the gill-bars and the atrial epithelium of the peri-branchial
wall; doubtless these are present also in other Ascidians, and have the
function of cleaning the walls of the atrium.
The cilia on the outer or lateral portions of the endostyle lash from
the endostyle groove on to the pharynx, and in this way doubtless function
mainly in transferring mucus secreted by the endostyle on to the walls of
the pharynx. These cilia, moreover, are probably seldom required to throw
particles on to the gill, for the tendency of the main stream will be to pass
towards the middle of the pharynx where the main pull on the water is
being effected by the lateral cilia. Herdman (9, p. 17) has estimated the
number of gill openings in an adult Ascidia mentula of medium size to be
about 192,000, and as there are rows of lateral cilia on each side of these
slits, there are in all about 384,000 short rows of cilia lashing water
through the pharynx of the animal; the main direction of the current
thus produced (see Figs. 7 and 8) is away from the endostyle. It is
therefore curious that this groove can ever have been regarded as an
important food-collecting organ. On the outer edge of the endostyle
of Ciona there are definite short transverse grooves in which the cilia
are specially powerful, and lash from the endostylar groove on to the
pharynx.
The median ciliated tract of the endostyle bears cilia up to two milli-
metres in length. Roule (8) describes the cilia as having a very slow
movement directed along the length of the groove and consisting of a
series of undulations beginning at the base of the cilia. I have not yet
been able to detect any movement in these cilia, and am therefore in
some little doubt as to their function. Since, however, food-particles are
not transported in the endostylar groove, these cilia do not appear to
have any transporting function. This view is further supported by
the fact that transporting cilia in Gastropods, Lamellibranchs (see 5,.
passim), and Amphioxus are always relatively very short and vibrate
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. 35
rapidly. Perhaps the function of these cilia may be detected by
examining their action through a microscope in the whole living and
feeding animal, and an attempt will be made to find an animal in which
this is possible. It is probable that they assist in passing mucus on to
the walls of the pharynx, as has been suggested for the similar cilia in
Amphioxus.
Examination of the peri-pharyngeal bands through a microscope shows
that the cilia in these grooves lash from the endostyle towards the dorsal
lamina. These grooves serve to collect and transport to the dorsal
lamina such particles as fall out of the main stream at the entrance to the
pharynx.
COMPARISON OF THE MODE OF FEEDING IN
AMPHIOXUS AND ASCIDIANS.
From the foregoing description it will be seen that there is an exact
correspondence in the mode of feeding in Amphioxus and Ascidians.
In these animals the lateral cia on the gill-bars are the main factors in
producing the main current ; mucus is passed on to the gill-bars by the
outer tracts of cila on the endostyle, and food-particles are collected and
transported to the dorsal region of the gill by the pharyngeal or frontal
cilia on the gill-bars. The food collected in the dorsal wall of the pharynx
is transported backwards, to be passed into the digestive tract. Thus
the diagram of the ciliary mechanism on the gill of Amphioxus (see Fig. 6)
will serve equally well for Ascidians in general, The cilia in the peri-
pharyngeal bands in both of these groups of animals lash from the
endostyle towards the dorsal groove, and collect and transport to the
dorsal groove those particles which fall out of the main stream at
the entrance to the pharynx. The process of feeding in both Amphioxus
and Ascidians is automatic, but at the same time these animals are
able to select from the food-stream the finer food-particles by means of
their buccal tentacles. Ascidians, moreover, have been observed to
reject food after it has been collected in masses on the gill by suddenly
contracting the walls of the pharynx and expelling the whole mass. It is
also not improbable that the pharyngocloacal slits observed by Garstang
in Ascidians (18, p. 132), may be exits from the pharynx used for
relieving that organ when overburdened with undesirable matter.
On the other hand Amphioxus is obliged to ingest all that passes
beyond the oral aperture.
36 J. H. ORTON.
THE FUNCTION OF THE GLAND AND ITS CILIATED TRACT
IN THE BRANCHIAL OPENINGS OF AMPHIOXUS AND
ASCIDIANS.
In the anterior region of these animals there are also similar organs
which have doubtless a similar function, and a function in connexion
with the mode of feeding. These organs are a gland, and a ciliated tract
connecting the gland with the pharynx, namely, the sensory pit or
Hatchek’s pit, and the Wheel Organ in Amphioxus, and the neural gland
and the dorsal tubercle in Ascidians. It has been suggested by V. Wijhe
(7, p. 121) and Andrews (14, p. 227) for Amphioxus, and by Herdman
(10, p. 52), Hartmeyer (11, p. 303), and Seeliger and Neumann (12, p. 61)
for Ascidians, that this gland may have the function of secreting mucus
which is passed on to the pharynx by the ciliated tract. The observations
here made on these groups of animals support these views. The gland |
probably merely secretes mucus which is passed on to the food-grooves
by the ciliated tract to serve for entrapping or embedding food-particles
and rendering the transportation of these easier than it otherwise would
be. Thus it is not improbable that the great variations observed in the
openings of the dorsal tubercle of Ascidians may be a means of distributing
mucus in various ways to the pharynx in correlation with minor differences
of food-collection on the pharynx ; such differences as may be due to the
well-known differences in structure of the pharynx.
From the occurrence of sensory cells in Hatchek’s pit in Amphioxus it
would seem that this organ is also in some way sensory, as V. Wijhe
(7, p. 120) has pointed out. In the light of the present researches it 1s
suggested that possibly this sensory pit may govern in some way the
supply of mucus from the gland itself and the endostyle, for the capture
of food-particles depends to a great extent on the amount of mucus
passing over the pharynx. Thus when a large amount of food-particles
is passing into the pharynx—as might be first appreciated by the
sensory cells in Hatchek’s pit—a large amount of mucus would be
required to capture the food-particles. It is therefore not improbable
that the supply of mucus may be regulated by means of this sensory pit.
Whether any similar function is exercised by the neural gland in Ascidians
is perhaps more doubtful, but both Herdman (10, p. 52-3) and Seeliger
and Hartmeyer (11, p. 303) suggest that the dorsal tubercle in these
animals may have a sensory function. It may also be pointed out here
that if the neural gland in Ascidians is an organ for secreting mucus
which is passed on to the pharynx by the cilia in the dorsal tubercle,
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. oF
then this mucus must be passed straight into the dorsal groove. The
cilia on the dorsal tubercle of Ciona when examined under a microscope
appear to lash away from the body-wall towards the lumen of the
branchial opening. Thus in the whole animal it is not improbable
that thin sheets of mucus are constantly passing from the dorsal
tubercle into the dorsal groove. These sheets would serve to entrap
food-particles in the same way as the ciliated tracts do in Amphioxus.
It is hoped, however, to complete these observations on a suitable
animal and to obtain more definite information on this subject.
THE MAINTENANCE OF THE PHARYNGEAL SPACES
IN ASCIDIANS AND AMPHIOXUS.
The maintenance of a current of water through the body of these
animals is dependent upon the maintenance of a continuous open passage
through the animal as well as upon the action of the gill as a water pump.
In Ascidians doubtless the main function of the test is to maintain a cavity
for the branchial sac. The body wall in Ascidians is maintained in close
contact with the test by organic connexions, so that the branchial sac lies
free in a cavity—the peri-branchial cavity—which the expanded pharynx
does not quite fill. Thus a cavity in communication with the pharynx
and the exterior is maintained outside the pharynx. The pharynx in
Ascidians is kept open by the intercrossing of longitudinal and transverse
bars of a sufficiently rigid consistency. In Amphioxus the pharyngeal
bars are supported, as is well known, by definite skeletal rods. The
peri-branchial cavity in Amphioxus, however, is maintained by dorso-
lateral sheaths of connective tissue arising from the notochordal sheath
(see Lankester, 16, Plate 36) held in position above the pharynx and
connected to the lateral surface of the notochord and dorsal skeletal
system by the myotomes. A glance at a pharyngeal section of this animal
indicates at once how the attachment of the myotomes to the dorsal
region of the body and the dorso-lateral sheaths in the wall of the peri-
branchial cavity maintains this cavity. Indeed, the shape of the
myotomes in Amphioxus may have been directly influenced by their
function of assisting in maintaining a cavity in the ventral region of
the body.
THE CILIATION OF THE GILL OF BALANOGLOSSUS.
Up to the present it has been possible to examine only sections of the
gill of this animal, but it is hoped that observations may be made on the
living animal later. Examination of sections of the gill-bars of Balano-
38 J. H. ORTON.
glossus (a species of Ptychodera) shows the presence of well-marked
lateral cilia and smaller frontal or pharyngeal cilia. From the fore-
going observations it is a fair deduction that these lateral cilia produce
the main current of water through the body of the animal, and that the
frontal cilia are concerned in some way in food-collection. It is also
highly probable that observations on this group of animals may now
demonstrate the function of the mucus, which is doubtless secreted by the
dorsal diverticulum, the gland in this group of animals corresponding to
Hatchek’s pit in Amphioxus and the neural gland in Ascidians.
OBSERVATIONS ON THE AMMOCOETE OF PETROMYZON
FL OVI LEG ES
Some observations have also been made on rather late stages of the
Ammocoete of Petromyzon fluviatilis. It is well known that this larva
closely resembles Amphioxus in some respects. I have also learnt from
fishermen that these larvee will live in captivity for even a year by merely
changing regularly the water in which they are kept. It was therefore
thought probable that they might feed on Plankton in the same way
as Amphioxus. Two specimens were fed on carmine particles and then
preserved in 90% alcohol. On opening the branchial portion of the
alimentary canal it was found that the carmine particles had become
entrapped in mucus and were collected along the gill-bars and roof of the
pharynx. No particles, however, were found in the intestine. Neverthe-
less sufficient evidence was obtained to indicate that further observations
on the mode of feeding in younger forms might be highly interesting, and
an effort will be made to make such observations.
THE MODE OF FEEDING IN SOLENOMYA TOGATA.
In view of the observations formerly made on the mode of feeding in
Nucula (see 5, pp. 467-70), similar observations undertaken upon any
other Protobranch promised to be interesting. Acting upon a happy
suggestion made by Sir H. Ray Lankester, I obtained living specimens of
Solenomya togata from Naples at the second attempt, and made the
following observations. An examination of this delicate little animal
through a microscope in water containing carmine particles readily
showed that as in Nucula the mantle cavity is divided into two chambers
when the animal is feeding. The food-current is drawn into the mantle
cavity at the antero-dorsal end and expelled posteriorly (see Fig. 7).
During the process of feeding the gills are extended so that their posterior
CILIARY MECHANISMS- ON THE GILL IN AMPHIOXUS. 39
ends touch the mantle postero-ventrally (see Fig. 7), and the lower
portions of the gill on each side also meet ventrally, while the tips of the
upper lamelle complete the partition of the mantle cavity by forming a
junction with the mantle dorsally. Thus a large anterior inhalent chamber
and a smaller posterior exhalent one are formed (as shown in Fig. 9), in the
same way as in Anomia aculeata and the higher Lamellibranchs. This
subdivision of the mantle cavity is of some importance, as it has been
regarded by some authors (for example, Sedgwick, p. 345) as occurring
only in the higher Lamellibranchiata. It will thus be seen that the whole
of the gills of Solenomya resemble generally one lamella of the gill of a
mussel for example.
INGOING
CURRENT
OUTGOING
CURRENT
Fic. 9.—View of a living specimen of Solenomya togata to show the relations of the gill
and the inhalent and exhalent chambers. (x ca. 10.)
G. Left gill.
I.Ch. Inhalent chamber.
E.Ch. Exhalent chamber.
A. Anterior end.
12 Posterior end.
D. Dorsal surface.
U.l. Upper lamelle of gill.
Ll. — Lower lamelle of gill.
J. Anterior end of the fused portion of the mantle.
T.C. Region where collected food is transported forwards as shown by the arrow.
The gill of Solenomya, it will be remembered, has the outer and inner
leaflets of the same side placed vertically, the one over the other, so that
both appear to form one leaflet with a shallow groove along the median
lateral line (see Fig. 9). These leaflets are arranged on an axis on each
side at the posterior end of body with only the thin edges of the leaflets
showing in a side view. The shape of a pair of leaflets may be seen in
Fig. 10.
On feeding the animal with carmine grains it was observed that the
food-particles collected on the outer faces of the gills were transported
quickly to the ventral edges—even from the upper leaflets—and thence
carried forwards towards the mouth to be eaten. The collection and
40 J. H. ORTON.
transportation of food-particles are effected by means of sets of cilia, but
in order to make out the actions of these different sets it is necessary
to examine separate living leaflets.
THE CILIATION OF THE GILL OF SOLENOMYA.
When two of the living leaflets (comprising a single pair) of Solenomya
are examined microscopically they are seen to resemble in general
characters those of Nucula (see Figs. 10 and 11). As in Nucula
the main current through the mantle cavity is produced by the
1s Ne
} in a
Fic. 10.—View of a pair of living leaflets of Solenomya togata taken from about the middle
of the gill, to show the directions in which the different sets of cilia lash. ( x ca. 60.)
The arrows marked A indicate the direction in which the lateral cilia lash to.
produce the main current; those marked C indicate the direction of lashing of the
latero-frontal cilia which act as food-strainers ; while those marked B show the
direction in which food-particles are lashed by the frontal cilia.
U.L. Upper lamella.
L.L. Lower lamella.
le. Lateral cilia forming a broad band on the side of the gill.
l.f.c. Latero-frontal cilia.
f.c. Frontal cilia.
C.D. Ciliated knobs.
I.c. Cilia interlocking with the mantle.
T.C. Cilia which transport food along the ventral edge of the gill towards the
mouth.
C.v. Cilia interlocking with similar ones on the adjacent leaflet.
lashings of the large lateral cilia on the anterior and _ posterior
faces of the leaflets (see Fig. 10, l.c. and the arrows marked 4A).
Food-particles are collected by the latero-frontal cilia (the presence of
which in this species has recently been doubted, see Ridewood, p. 193)
and frontal cilia, but transported solely by the latter (see Fig. 10, l.f.c.
and f.c.). The latero-frontal cilia lash in a direction across the length
of the edges of the leaflets, i.e. away from the spaces between the leaflets
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. 4}
(see the arrows marked C in Fig. 10). They catch the food-particles which
tend to be drawn between the leaflets in the main current and pass them
on to the frontal cilia. The latter lash in a ventral direction, and thus.
send particles along the edges of the leaflets to the ventral surface (see
Fig. 10, f.c. and the arrows marked B). Here a group of cilia now lash the
food-particles anteriorly towards the mouth to be eaten. As the food-
particles are lashed along the face of the gill they become embedded in
mucus, which is doubtless secreted by the epithelium of the gill. The
| “DIRECTIONS /N WHICH
LATERAL CILIA LASH
Fic. 11.—Anterior view of a living pair of leaflets of the right gill of Nucula. (x about 65.)
The leaflets anterior to the pair depicted were cut away.
ab.f.c. Ab-frontal cilia.
cd: Patches of cilia on the inner and outer leaflets.
D.A. Dorsal surface of gill about the 30th pair of leaflets from the posterior
end of gill.
Ee: Frontal cilia.
Le.d. Cilia effecting a junction with similar cilia on the left gill.
1E1be Inner leaflet of gill.
Ke: Lateral cilia.
Pics Latero-frontal cilia.
O.L. Outer leaflet of gill.
O.c.d. Cilia effecting a junction with the mantle.
aC, Cilia which transport collected food forwards.
secretion of mucus on the Lamellibranch gill is indeed a matter of con-
siderable importance in the feeding process, and it is hoped to investigate
the matter more fully later.
The examination of single living leaflets reveals a feature of much
interest in the ciliation of the gill. On the inner edges of the leaflets,
that is, on the ab-frontal surfaces, there occur numerous ciliated knobs
(see Fig. 10, c.d.). These ciliated knobs have cilia whose motion is like
that of the ciliated discs on the gill-filaments of the Filibranchia (for
example see the Fig. of Mussel, Orton, 5, p. 465). This motion may be
42 : J. H. ORTON.
compared to that of the bristles of two brushes when the brushes are
rubbed together slowly in a rotary manner with the bristles interlocking.
To get the proper effect one brush should be started rotating before the
other, and the bristles should be regarded as vibrating at the same time
with a slow wave-like motion which begins at the attached end.
The function of these ciliated knobs is doubtless the same as that of the
ciliated discs of the Filibranchia, namely, to interlock with similar dises
on the leaflets of the gill on the other side of the body; or, in the case of
the anterior leaflets, with cilia on the side of the body of the animal.
When suitable material can be obtained sections of the whole gill will be
made to show the interlocking of these cilia. The number of ciliated
knobs on the gill-leaflets varies in different parts of the gill. Thus in one
specimen examined there were only two or three on the anterior upper
leaflets and twelve in the corresponding lower leaflets. Behind this point
the knobs increase in number, so that at the beginning of about the
middle third of the gill there were ten or eleven in the upper and thirty
to forty in the lower. In about the middle of the gill there are still more
knobs on both leaflets, thirty-five to forty being counted on the upper
ones, but the number on the corresponding leaflet was not made out.
In front of the posterior end about thirty-six knobs were counted in the
upper and eighteen to twenty in the lower leaflets. There are thus more
knobs in the middle of the gill and fewer at the anterior and posterior ends,
and more in the lower leaflets in the anterior end than in the upper ones
in this position, but more in the upper than in the lower at the posterior
end. These differences are doubtless explained by the facts that at the
anterior ends of the gills the upper leaflets appear to lie against the body,
while the lower ones meet below, and thus require a better interlocking
arrangement, while at the posterior end of the gill the upper leaflets are
longer than the lower ones.
Besides these ciliated knobs there are also other interlocking cilia
at the tips of the upper and at the ventro-lateral edges of the lower
leaflets (see Fig. 10, I.c.). These cilia doubtless effect a junction with the
mantle, and an attempt will be made to obtain sections of the gills and
mantle to show these connexions.
On the anterior and posterior faces of the ventral edges of the lower
leaflets there are patches of cilia which also have the rotary motion
characteristic of interlocking cilia. These probably serve—like the
similar patches on the gill leaflets of Nucula (see Fig. 11, c.d.)—to hold the
tips of the leaflets together. Thus the living gill of Solenomya is a very
compact organ, which, however, like that of Pecten, can be contracted
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. | 43
into a small compass so as to leave the inhalent and exhalent chambers
continuous.
The characters of a transverse section of a gill-leaflet of Solenomya
can now be recognized. Ridewood (p. 193) in describing the ciliation
of the gill remarks, ‘‘ Cilia are confined to the thickened edge, and appear
to form a continuous investment of it, not differentiated into frontal
and lateral tracts. The material available is not sufficiently well pre-
served to allow of a definite statement upon this point, but it is worthy of
remark that no gap between the frontal and lateral cilia is shown in the
figures (of the transverse sections) given by Pelseneer, Kellogg, and
Stempell. The cilia extend as far as the level of the outer edge of the
thickened chitin bands, and the shortest are those on the frontal surface.
Pelseneer shows large latero-frontal cilia, but this is possibly an error.”
The foregoing examination of the living leaflets shows that Pelseneer’s
-depiction of large lateral cilia (the latero-frontal cilia) is correct, and that
all figures err in depicting a continuous covering of cilia at the tip of the
gill (see Fig. 10), thus justifying Ridewood’s cautious remarks in this
respect. A transverse section may or may not show cilia on the ab-frontal
face according as the section passed through a ciliated knob or not.
An attempt will be made to make preparations from well-preserved gills
-and to figure a transverse section.
RESEMBLANCE OF THE CILIATION OF THE GILL
IN SOLENOMYA AND NUCULA.
From the above description of the ciliation of the gill of Solenomya
it will be seen that there is a close resemblance to that obtaining in
Nucula (see Fig. 11). If the frontal surfaces of these gills be compared a
‘complete resemblance in this part is seen; frontal, latero-frontal, and
lateral cilia occurring in both and having the same function in both. The
.ab-frontal cilia of the gill of Nucula, however, are absent from that of
Solenomya, and are replaced by ciliated knobs. The small patch of inter-
locking cilia on the lateral faces of the leaflets of Nucula have not been
seen in Solenomya, but a patch of interlocking cilia is present on the
ventro-lateral portion of the inner leaflets of both gills (see Figs. 11, ¢.d.,
and 10, ¢.v.). Cilia interlocking with the mantle are present in both forms
at the tips of both leaflets; those in Solenomya are, however, nearer to
the frontal surface than in Nucula in correlation with the difference in
position of the gill in the former. On the whole, therefore, the ciliation
-of the gill of Solenomya bears a very close resemblance to that of Nucula.
44 J. H. ORTON.
SUMMARY OF THE ACCOUNT OF THE CILIARY
CURRENTS IN SOLENOMYA.
The main current through the mantle cavity is effected by means of the:
lashings of the lateral cilia on the gill-leaflets. This current is drawn in
at the antero-dorsal region of the shell and expelled in the posterior:
region. The food-particles brought to the gill m this current are arrested
on the gill by the latero-frontal and frontal cilia, the former passing on
particles to the latter. The frontal cilia transport the food-particles.
along with mucus, which is doubtless secreted by the epithelium of the
gill, on to the ventral edges of the lower leaflets, whence a special group:
of cilia transport the collected particles and mucus towards the mouth
to be eaten.* Ciliated knobs occur on the ab-frontal edges of the leaflets.
which serve to interlock with similar knobs on the fellow-leaflets on the
other side of the body. Long interlocking cilia also occur at the dorsal
ends of the upper leaflets and the ventro-lateral edges of the lower ones.
These cilia serve to effect a junction of the gills with the mantle durmg
feeding, and so divide the mantle cavity into an inhalent and an exhalent
chamber.
On the whole, therefore, it is seen that the gill of Solenomya, like that.
of Nucula, is essentially similar to that of the higher Lamellibranchs.
Indeed the presence of numerous ciliated knobs must rank this gill as a.
more highly specialized one than, for instance, that of Anomia aculeata,.
which has only interlocking arrangements at the tips. Apart from the
narrowness of the filaments in A. aculeata, there is almost an exact
resemblance between the gills of this species and those of Nucula and
Solenomya togata. Thus the gross structure and the function of the gills.
in the Protobranchia and the Filibranchia have been shown to be essen-
tially similar, and there can_be>very little doubt from the published
accounts of the gills of other Protobranchia that these may be regarded
as essentially similar to those of Solenomya and Nucula.
THE FUNCTION OF THE GILL IN LAMELLIBRANCHS.
The gill in all groups of Lamellibranchs has now been shown to be a.
feeding organ. Generally, however, this organ is regarded as being
chiefly a respiratory and only secondarily a feeding organ. In the light
* Since this account was sent to the printer, a paper by E. 8. Morse on Solenomya
in the current number of the Biological Bulletin, Woods Hole, has come to hand.
This paper gives an account of observations on living Solenomya velum and S. borealis.
Morse has observed the palps being used for transferring food from the gill to the mouth,
which fact, added to those given above, completes our knowledge of the mode of feeding:
in Solenomya.
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. 45
of recent researches on the function of the gill, however, it would appear
that the order of importance in which these functions have been regarded
must be at least reversed. The expenditure in the gill of the relatively
large amount of energy necessary to produce the main current and food
currents must enormously outbalance the aerating effect of these currents
on the gill. For it is to be remembered that in the gill-filaments of
Lamellibranchs the blood is not contained in a capillary plexus, but
usually in a blood vessel sunk well below the epidermis. This con-
clusion with regard to the function of the Lamellibranch gill has
indeed already been arrived at, from a morphological point of view,
by Dakin (6, pp. 52-3), who states that in the genus Pecten “It seems
certain, from the development of vessels in the mantle, that the great
function of the gills is to produce currents of water for aeration, nutrition,
and the carrying away of waste products, and the only parts of the gills
performing any really important duty in respiration are the branchial
expansions of the principal filaments.” There is little doubt that this
statement might now be made similarly of the whole of the higher
Lamellibranchs. It is of interest, however, that there is one important
difference in this respect in the gills of the Protobranchia. In this group
the gill-filaments are broad and lamellate, and contain an extensive space
between the two surfaces (see Ridewood, p. 193) over which we have seen
the current passes. Doubtless with this type of gill a much greater
proportion of the whole respiration is effected in the gill than is the case
in the forms with narrow compact filaments. But even here it may
be doubted whether respiration is effected to the same degree in the gill
as in the mantle. It would be highly interesting in these respects if a
ready means could be found of detecting the relative amounts of waste
products in any particular part of the body at any particular instant.
Such an experiment may perhaps not be an impossibility, as some of these
animals can be observed living through a microscope.
APPENDIX.
Some of the observations made in the section on the function of the
Wheel Organ and Peri-pharyngeal bands in Amphioxus (p. 25) have
already been noticed by Andrews in the Bahamas Amphioxus, as will be
seen from the following quotation. It was unfortunately not possible
to refer to Andrews’ work in the general text, as some difficulty was
experienced in obtaining his paper, which only became available after
the text had gone to the printer.
Andrews ( 4) obtained living specimens of the Bahamas Amphioxus
46 J. H. ORTON.
(Asymmetron lucayanum) about which he observes: ‘As the animal is
small and translucent, the course of food and carmine granules may be
traced through most of the digestive tract. The strong current of
water setting into the pre-oral chamber seems to be controlled by the
longitudinal, ciliated ridges of Miiller’s ‘Raderorgan’ which pass for-
ward from the velum on the inside of each lateral wall of the pre-oral
chamber. Thus the carmine granules pass rapidly along these ridges
towards the velum, where they are turned inward towards the aperture,
mouth, at the centre of the velum. The granules pass along in strings
as if held together by a thin mucus; once through the mouth they do
not pass out through the pharyngeal slits, but continue along the
median dorsal pharyngeal groove, the hyper-pharyngeal groove, still
adhering to one another in strings. In actual longitudinal and cross
sections these strings of granules may still be recognized in the ciliated
hyper-pharyngeal groove.
“This groove leads into what may be called the stomach, within
which the current of granules, or the granule containing mucous strand,
turns abruptly downwards and forwards as indicated in the above
diagram, yet does not enter the diverticulum, but, still under the control
of the active cilia lining the digestive tract, passes back again through
the centre of the stomach. It is now revolving rapidly in a constant
direction from right to left, and continues to do so throughout the next
division of the digestive tract, the first or larger section of the intestine.
In this part of the intestine the granules, diatomes, etc., collect into
clumps separated by the clear part of the continuous mucus-like
strand. In this region the intestinal epithelium is especially modified
in a zone that became very prominent when staining reagents are used.
‘The second, final and smaller part of the intestine, contains pellets
of detritus that become successively larger towards the anus, where they
have the form of elongated, not spherical, masses that are discharged
from the anus as the anal sphincter relaxes from time to time. The
mucous strand is here broken, the granular aggregates becoming isolated
from one another. These balls or pellets move along but slowly, and
give up the revolving motion seen in the first part of the intestine and
in the stomach.
‘The time elapsing from the addition of carmine to the water to the
discharge of carmine containing pellets may be much less than one
hour.”
It will thus be seen that Andrews has described some of the processes
in the subsidiary method of feeding in the Bahamas Amphioxus which
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. 47
is doubtless the same as in the Plymouth Amphioxus. He gives the
impression, however, that this is the main method of feeding, but such
is not the case, as will have been seen from the foregoing description.
SUMMARY.
The mode of feeding in Amphioxus is effected by—
(1) The maintenance of a stream of water through the pharynx by
rows of lateral cilia on the gill-bars.
(2) The throwing out of mucus from the endostyle on to the gill-bars
to serve for entrapping food-particles.
(3) The collection of food-particles by rows of cilia on the pharyngeal
surface of the gill-bars; these cilia work up the food-
particles with mucus into cylindrical masses and transport
such masses dorsally into the dorsal groove which carries
the collected masses backwards into the digestive tract.
Thus the ciliary mechanisms on a gill-bar of Amphioxus are exactly
the same as those on the gill-filaments of some Lamellibranchs, as Pecten,.
and some Gastropods, as Crepidula.
A subsidiary mode of food-collection is effected in the buccal cavity
of Amphioxus by the ciliated tract known as the wheel organ, and
Hatchek’s pit, which supplies mucus for entrapping food-particles.
These particles are passed on to the peri-pharyngeal bands which
conduct them in turn into the dorsal groove.
The gill of Amphioxus functions mainly as a feeding organ and a water
pump, and probably not at ali as an organ for aerating the blood.
The mode of feeding in Ascidians is almost exactly the same as that
described above for Amphioxus. Food-collection, however, in Ascidians
is effected by cilia on the papille and similar outgrowths on the gill,
and is also helped in some forms by transverse waving of the
longitudinal bars, by which process the food is pushed as well as
lashed towards the dorsal region of the pharynx.
The observations here made lend support to the view that the neural
gland in Ascidians is an organ for secreting mucus, which aids in the
capture and transportation of food-particles, and that the dorsal tubercle
of Ascidians is an organ for passing mucus on to the pharynx; the
corresponding structures in Amphioxus, namely, Hatchek’s pit and the
wheel organ, are here shown to effect food-collection in the buccal cavity.
The cavity in the body of Ascidians through which the food stream
48 J. H. ORTON.
can pass is maintained by the test, and in Amphioxus by the expansion
of stout connective sheaths over the dorsal region of the pharynx held
in place by muscular attachments to the dorsal region of the body.
The ciliation of the gill-bars of Balanoglossus is essentially the same
-as that of Amphioxus. Hence the current of water through the body
of the animal is doubtless effected by the lateral cilia and a mode of food-
collection effected by the frontal cilia.
Observations on late Ammocoete larvee indicate food-collection on the
gill-bars and the roof of the pharynx, as occurs in Amphioxus. An
attempt will be made to complete these observations.
The mantle cavity of Solenomya togata is divided into inhalent and
exhalent chambers by the gill in the same way as in other Lamellibranchs,
namely, Anomia and Pecten.
The ciliation of the gill of Solenomya closely resembles that of Nucula :
the lateral cilia produce the main current, the latero-frontal and the
frontal cilia collect food-particles, and the latter transport them to the
ventral surface of the gill, whence they are conducted forwards by
special transporting cilia towards the mouth to be eaten.
Numerous small ciliated knobs occur on the ab-frontal face of the gill-
lamelle and serve to interlock with their fellows on opposite leaflets.
These ciliated knobs correspond to the ciliated dises of the gill-filaments
of other Lamellibranchs, for example, the Mussel.
Interlocking cilia occur on the edges of the upper and lower leaflets
of the gill and serve to lock the gill to the inner wall of the mantle,
and thus to partition the mantle cavity.
The function of the Lamellibranch gill is probably mainly that of a
food collector and a water pump, and except in the Protobranchs 1s
probably not an organ in which aeration of the blood occurs.
REFERENCES.
1. A. Willey. Amphioxus and the Ancestry of the Vertebrates. Mac-
millan & Co. 1894.
Feeding of Amphioxus, pp. 9, 39. Feeding of Ascidians, p. 185.
2. A. Sedgwick. Student’s Text Book of Zoology, Vol. II. London,
1905, p. 22.
3. Delage and Hérouard. Traité de Zoologie concréte VIII. Pro-
chordés p. 113, p. 144, Asczdians.
4. H. Fol. Etudes sur les Appendiculaires du détroit de Messine.
Mém. de la Société de Phys. et d’hist. natur. de Genéve.
Tex 2: 1ST2:
CILIARY MECHANISMS ON THE GILL IN AMPHIOXUS. 49
J. H. Orton. Journ. M.B.A., Vol. [X, No. 3. 1912. Gull of Nucula,
pp. 467-70. .
W. J. Dakin. L.M.B.C. Memoir XVII. Pecten. 1909. pp. 52-3.
J. W. van Wijhe. Beitrige zur Anatomie der Kopfregion des
Amphioxus lanceolatus.
Petrus Camper I, p. 121. 1901-2.
L. Roule. Recherches sur les Ascidies simples des cOtes de Provence
(Phallusiadées), p. 66.
Ann. du Mus. d’Hist. Nat. de Marseille. Zoologie. Tome II.
Mem. No. 1. 1884.
W. A. Herdman. Cambridge Nat. Hist., Vol. VII. Fishes, Ascidians,
etc., 1904, p. 45 feeding, p. 47 lateral cilia, pp. 52-38, neural
gland and dorsal tubercle.
W. A. Herdman. L.M.B.C. Memoir, Liverpool. 1. Ascidia. pp. 14,
15 endostyle.
O. Seeliger and R. Hartmeyer. Bronn’s Tier-reich, III. Supplement,
I Abteilung. 1893-1911, pp. 302-3.
O. Seeliger and C. Neumann. Bronn’s Tier-reich III. Supplement,
II Abteilung. 1913, p. 61.
W. G. Ridewood. Phil. Trans. Roy. Soc. London. B. Vol. 195.
1903, p. 193. pe?
~ KE. A. Andrews. Studies from the Biol. Lab. of the Johns Hopkins
Univ., Vol. 5, No. 4. 1893.
W. Blaxland- Benham. Q.J.M. Sci., Vol. XXXV, p. 9, Plate 6,
Figs. 1 and 2. 1893.
EK. Ray Lankester. Q.J.M. Sci., Vol. XXIX, Plate XXXVI. 1889.
H. Fol. Ueber die Schleimdriise oder den Endostyl der Tunicaten,
Morphologisches‘Jatrbuch. Bd. I. 1876.
W. Garstang. Journ. M.B.A. Vol. 2. N.S. 1891-2, p. 132.
NEW SERIES.—VOL. X. NO. ]. NOVEMBER 1913. D
The Electrical Conductivity of Fertilized and
Unfertilized Eggs.
By
J. Gray, B.A.,
King’s College, Cambridge.
Tue following is a preliminary account of some experiments carried out
this summer at Plymouth. They were undertaken with a view to the
investigation of the changes, both physical and chemical, which are
induced in the egg by the entrance of a spermatozoon.
No attempt is made to discuss the results in the light of current theories
regarding the phenomena of fertilization, as it is hoped that further
work will make such discussions more profitable than would be the case
at present.
APPARATUS.
In order to determine the electrical conductivity of the eggs, a con-
ductivity cell was used such as would fit the holder of a small hand
centrifuge. The tube was about 10 cm. long and 1 cm. in diameter.
The electrodes were two square platinum plates each possessing two equal
surfaces of 25 sq. mm. These were fixed about 25 mm. apart and were
carried by two silver wires which passed through glass tubes, and which
were fixed through the stopper of the tube.
In some of the earlier experiments the volume of the eggs in the tube
was determined by marking their level with a fine pointed grease pencil,.
but in all the later experiments the tube was graduated.
This form of conductivity cell has two advantages—it fits ito the
holder of an ordinary centrifuge, and the volume of eggs required is small.
The latter point is of great importance, quite apart from the difficulty in
obtaming large quantities of ripe Echinus eggs. If too many eggs are
enclosed within a tube, it is not only impossible to ensure a good per-
_ centage of fertilizations by adding a small quantity of sperm, but the over-
crowding of the eggs interferes very considerably with the development
of the eggs subsequent to fertilization, i.e. the rate of division differs very
considerably from that of similar eggs in a large bulk of water; m extreme
ELECTRICAL CONDUCTIVITY OF FERTILIZED AND UNFERTILIZED EGGS, 52
cases the development ceases at an early stage. In all my experiments,
except where specially mentioned to the contrary, the eggs developed
normally, although in some cases more slowly than the controls.
The temperature at which the experiments were made never differed
much from room temperature, so that it was found possible to keep the
temperature of the eges constant to within 75° centigrade by means of a
simple thermostat. The whole apparatus stood in a large earthenware
bowl containing water at room temperature.
The alternating current. was obtained from a 2-volt accumulator
connected to a small induction coil of high frequency. The resistance was
measured by means of a Kohlrausch bridge (half a metre in length), and a
telephone. The electrodes were platinized in the usual way by means
of platinie chloride with a trace of lead acetate. The induction coil was
placed outside the room in which the experiments were made, and by keep-
ing the electrodes well platinized it was possible to obtain quite distinct
minimal points with an ordinary telephone.
METHODS.
The procedure adopted during the whole of the experiments was as
follows: The ovaries of a perfectly ripe female were shaken in one or
more finger-bowls containing “outside”’ water. The ovaries were
removed after five or ten minutes, and the sea-water containing the eggs
filtered through a suitable piece of bolting silk. In this way any loose
pieces of ovarian tissue were removed from the eggs. The latter were
now allowed to settle to the bottom of the bowl. The ripe eggs settled
somewhat slowly, but after a short time sufficient eggs for one experiment
could be drawn off in a clean pipette; thence they were transferred to the
conductivity tube. The requisite amount of eggs having been so ob-
tained, the tube was filled up with clean sea-water, corked and allowed
to stand in a bow] of sea-water until the eggs had again settled sufficiently
for the bulk of the sea-water to be removed. This having been done, the
egos were again washed in clean sea-water. After two or three such
washings all the small fragments of tissue smaller than the eggs were
removed, and the tube contained nothing but ripe eggs in clean sea-
water. After washing in this way the eggs settled somewhat more
readily than when removed from the ovary, owing to the removal of the
gelatinous ovarian membranes. The conductivity tube containing the
eggs was then transferred to the thermostat and left until the eggs had
settled to a definite volume which could be estimated without any
difficulty. Great care was used to ensure that the eggs settled uniformly
52 J. GRAY,
in the tube; if this precaution is not observed it will be found that
repeated estimations of the resistance of the same eggs occupying the same
volume give very variable results. It was found possible, however, to
collect the eggs in such a way as to obtain uniform readings from repeated
observations. To ensure an equal distribution of the eggs is a matter of
great difficulty in the case of experiments dealing with resistances below
20 ohms ; above this, however, the difficulty can be overcome by patience
and repeated washings of the eggs.
The volume of the eggs having been accurately determined by means of
the graduation on the tube, some of the sea-water was removed from the
tube and the electrodes placed in position and the resistance of the eggs
determined.
The electrodes were then removed and the tube filled with fresh sea-
water (care being taken not to remove any eggs with the electrodes).*
One or two drops of a dilute emulsion of sperm were then added and the
tube inverted so as to distribute the eggs equally through the sea-water.
After a minute the tube was allowed to stand in the water of the
thermostat, until the eggs had again settled to the bottom of the tube.
It was usually found that the fertilized eggs occupied a larger volume
than the same eggs unfertilized ; in such cases the tube was transferred
to a hand centrifuge and very gently centrifuged to the required volume.
The excess of sea-water was again drawn off and the electrodes placed in
position and the resistance of the egg determined. The use of the centri-
fuge was avoided as far as possible for fear of injuring the eggs ; it was
found, however, that gentle use of the machine had no effect on the
resistance of unfertilized eggs, or upon the subsequent development of
fertilized egos. If, however, the uniertilized eggs were so compacted
as to require rather vigorous use of the centrifuge, the experiment was
discontinued after the estimation of the resistance of the fertilized eggs.
Such eggs were usually found to be crushed although not broken, and
when returned to abundant sea-water the large majority developed
normally.
After each estimation of the resistance of the eggs, the conductivity
tube was filled with fresh sea-water and immersed horizontally in sea-
water whose temperature never differed from that of the thermostat by
more than 1° C.
Objections may be raised against the conclusion that the observed
differences in resistance of eggs at different stages of development are
* When not actually in use the electrodes were kept immersed in clean sea-water.
+ These remarks apply to eggs which gave a resistance of 70 ohms and upwards.
ELECTRICAL CONDUCTIVITY OF FERTILIZED AND UNFERTILIZED EGGS. 53
due to the direct effects of fertilization. The following alternative sugges-
tions might be offered :—
1. That the changes are due to the injurious effect of the current upon
the eggs. For this, however, evidence is entirely unavailable. Eggs
upon which definite and prolonged experiments had been made on June
18th were transferred to a bowl of clean sea-water, all the eggs divided
normally, and all gave healthy larvae. Some of these early plutei were
placed in a sterilized jar and fed with a pure diatom culture ; on July 11th
the plutei were large and healthy. They had developed at a normal rate,
and a definite Hchinus rudiment was visible. Several such observations
of the development of egos whose resistance had been measured were kept,
and in each case the development was perfectly healthy and normal.*
It is therefore, I think, safe to conclude that the eggs were unaffected
by the passage of the current used in these experiments.
2. That the changes are due to experimental error in returning the eggs
to the same volume. To determine the degree of error due to such a
source, | made successive determinations on the resistance of the same
lot of unfertilized eggs. I found that the variation of the readings never
exceeded 2° of the total resistance (In many cases successive readings
were identical). Now such a difference might perhaps explain experi-
ments in which the total resistance is below 20 ohms, but is quite in-
adequate for the much larger differences which were regularly observed
for eggs compacted to give higher resistances.
3. That the decrease in resistance of the eggs subsequent to fertilization
is due to the presence of the fertilization membrane and not to the
substance of the egg itself. It cannot, however, be suggested that the
spaces between the egg are enlarged by the membrane, for the unfertilized
egos are not crushed during the experiments, and any crushing undergone
by the fertilized eggs is at the expense of the membrane and not of the egg.
If the eggs are closely compacted after fertilization it is almost invariably
found that either the membranes are much wrinkled or are removed
entirely from the egg on the addition of fresh sea-water. Again, during
the course of the experiments it was found that the fertilization membranes
in some batches of eggs were never pushed far out from the egg, but
* In the case of Echinus miliaris plutei, which according to Shearer, De Morgan and
Fuchs fail to develop their green pigment if unhealthy, my cultures invariably possessed
this character and were, in the opinion of Dr. Shearer, perfectly healthy. (Most of the
cultures were discarded as soon as the Echinus rudiment had reached considerable size, but
in two cultures which were preserved the larve underwent perfectly typical metamor-
phosis—a little more than a month after fertilization, which is in agreement with the rate
of development of the egg under normal conditions. )
54 J, ORAS
remained rather closely applied to the ege-surface; in such cases the
resistance of the fertilized eggs was, as in other cases, markedly lower
than that of the unfertilized eggs. It was also found that eggs from
which the fertilization membrane had been forcibly removed developed
quite normally. Now Loeb has shown that the fertilization membrane
is permeable to electrolytes, and I therefore conclude from the above
facts that the presence of a membrane round the eggs is equivalent to a
similar quantity of sea-water, and that when the eggs are reduced
to the same volume as before fertilization, the distance between the eggs
is identical.
The fact that after the initial fall in resistance of the eggs after fertiliza-
tion there is a definite and well-marked rise in resistance, eliminates the
suggestion that the changes observed are due to the presence of a fertiliza-
tion membrane. Again, in a few cases (i.e. In experiments dealing with
high resistances) a considerable number of the membranes are removed
from the egg whilst determining the resistance of the fertilized eggs, so
that when sea-water is added the membranes are found floating in it.
If the eggs are not allowed to settle at once they are found still to have a
resistance equal to the value obtained by the first determination after
fertilization.
4. That the observed differences are due to the existence of free sper-
matozoa between the eggs. This is not the case, because (1) the addition
of as much sperm as was used in any of these experiments does not alter
the conductivity of a bulk of water equal to that of the eggs; (2) the
conductivity of a concentrated emulsion of sperm is considerably lower
than that of pure sea-water.
(Nore.—McClendon states that by repeatedly washing the unfertilized
eggs of Arbacia he was able to prevent the formation of a fertilization
membrane when the sperm entered the egg. I have never observed this
in the eggs of Hchinus, but prolonged washing tends to prevent the
membranes being pushed out to their normal extent.)
ELECTRICAL CONDUCTIVITY OF FERTILIZED AND UNFERTILIZED EGGS. 55
TABLE I.
EXPERIMENTS WITH Hehinus acutus.
Minutes after
Resistance in Ohms addition of
of sperm that
Unfertilized Fertilized determination (Re—Ry) 100
Eggs (Rv) Eggs (R,) of Ry wasmade R,—R; Ru
ule 17-3 16-5 6 1-0 5:8
we 22-5 21-5 10 1-0 4-4
3. 30-0 28:5 10 1-5 5-0
4, 30°5 27°8 12 2-7 8:8
a: 36°5 34-0 15 2-5 6:8
6. 38-0 29-7 6 8-3 21-8
(ig 39°7 36:5 10 32 8-0
8. 40-5 37D 7 3-0 7-4
uw 40-6 37°D 9 Jl 7:6
10. 41-0 38-0 8 3:0 7:3
Vid 41-5 38:5 3 3°0 7-2
12. 42-8 40-8 ll 2-0 OT
13. 43-0 39-0 10 4-0 9-3
14. 44-0 39-0 15 5-0 11:3
15. 44-0 33°0 2 11-0 25-0
16: 44-0 43-5 13 “5 ta
ET. 45-0 41-0 6 4-0 8-9
18. 45-0 41-0 9 4-0 8-9
13h 45-0 36°5 7 8:5 18-9
20. 46-0 41-0 15 5-0 10-9
21. 47-3 40:5 14 6-8 14-3
22. 49-0 45-0 4 4-0 8-1
23. 49-0 48-0 15 10 2-0
24. 50-0 44-0 LL 6-0 12-0
25. 50:8 46-0 5 4-8 “9-4
26. 51-0 41-5 lil 9-5 18-6
ake 51-0 40-0 7 11-0 21:6
28. 54-0 47-0 6 7:0 12-9
29. 54-5 48-7 13 ee) 10-6
30. 66-0 48-7 20 17-3 26-2
3l. 72:0 59-5 !. 12-5 17-3
32. 75:5 63-0 10 12-5 16-5
33. 80-0 68-5 5 11-5 14-6
34. 85-0 75-0 15 10-0 7
35. 87-0 78-0 10 9-0 10-3
36. 100-0 89-0 15 11-0 11-0
11:2
Average value of a =
U
56
TO OU HR Co DD Re
© 0
OU oo po
J. GRAY.
TABLE II,
EXPERIMENTS WITH Echinus miliaris
Resistances in Ohms
of
Unfertilized
Eggs (Rv)
16-0
16-4
19-1
26:5
30-0
o2°D
32°5
42-0
45-5
47-0
49-5
56:5
60-0
61-0
65-0
65-0
76-0
Average value of
EXPERIMENTS wWIitH Echinus esculentus.
Fertilized Mins. after
Eggs (R,) Fertilization R,—
15-4 15 0:6
15-5 15 0-9
17-0 8 2-1
25:5 5 1-0
29-0 8 1-0
29-5 18 3:0
31-0 12 1-5
39°D 10 2°D
41-0 20 4-5
40-3 15 33
45-5 10 4-0
41-0 21 15:5
56-0 10 4-0
51-0 7 10-0
50:5 10 15-5
55-0 15 10-0
61-0 15 15-0
(Ry—R,) 100 _ .
—_ a9 =10°9
Tasie III.
Resistances in Ohms
of
Unfertilized Fertilized Mins, after
Eggs (R,)
88-0
40-0
Eggs (Ry) Fertilization R ,—Rr
72 10 16-0
oT 6 3°0
TABLE IV.
EXPERIMENTS WITH Asterias glacialis.
Resistances in Ohms
of
Unfertilized
Eggs (Rv)
29-0
33:0
35°5
37°5
41-5
Average value of
Fertilized Mins. after
Eggs (Rx)
27°5
29-0
33°0
34-5
39-5
Fertilization R,—R,
12
15
10
15
8
(R.—Rz) 100_
Re os
15
4-0
2°5
30
2-0
T4
(Rv—Re) 100
Ry
18-2
7:5
ELECTRICAL CONDUCTIVITY OF FERTILIZED AND UNFERTILIZED EGGS. 57
TABLE V.
Resistance of Resistance of Fertilized Eggs
Unfertilized = Within 15 mins. 15-44 mins. after
Kggs of Fertilization Fertilization
1. Echinus acutus 30-0 28-5 (10) 29-5 (32)
2. ss 59 43-0 39-0 (10) 43-0 (38)
3. . 3 46-0 41-0 (15) 43-5 (30)
4, . 38-0 29-7 (6) 31-0 (27)
5. : » 45-5 36:5 (7) 37°3 (28)
6. ‘ f 51-0 40-0 (7) 41-5 (27)
t 2 4 ~ 45-0 41-0 (9) 42 (26)
8. fs ; 50-8 46-0 (5) 51 (20)
Se ; ‘ 49-0 45-0 (4) 50-5 (15)
10. is 80-0 68-5 (5) 80 (16)
i. : es 54-0 47-0 (6) 54 (27)
12 ss 12:0 59-5 (9) 64-0 (27)
13. 5 42-8 40-8 (11) 42-8 (38)
14, 5 41-5 38-5 (3) 40-0 (17)
15. e - 54-5 48-7 (13 48-7 (30)
16. Hchinus miliaris 32:5 29-5 (18) 32:0 (38)
ii 3 3 42-0 39°D (10) 41-0 (44)
18. 5 53 65-0 50-5 (10) 52-5 (28)
19. Asterias glacialis 375 34-5 (15) 35°5 (27)
20. a 3 33°0 29-0 (15) 30°5 (31)
The figures in brackets in columns 2 and 3 indicate the actual number of
minutes after the addition of sperm to the eggs.
CONCLUSIONS.
From these experiments I draw the following conclusions :—
1. That the entrance of the sperm into the egg causes an increase in
electrical conductivity of the egg. This condition usually attains
its maximum within ten minutes of adding sperm to ripe eggs.
2. That this increase in conductivity is followed by a process which
returns the conductivity of the egg to or towards that of the
unfertilized egg.
The chief limitation of the method lies in the fact that in order to get a
measurable change in resistance between the electrodes after fertilization,
the eggs must be concentrated to give an initial resistance of about 30-40
ohms. In order to cover the electrodes with the eggs, at least $ c.c. of eggs
is required. The volume of sea-water which the eae tie cell can
hold is about 10 c.c. ; the effect of these conditions is that when the eggs
are shaken in sea-water after the determination of their resistance they
58 J. GRAY.
are so crowded that they develop at a rate different from that of control
eggs kept in abundance of water. The change in rate of development
varies with different batches of eggs and with their degree of concentration.
Hence it is impossible by this method to determine the conductivity of
normal eggs (i.e. eggs developing at a normal rate) at any stated moment.
As, however, the development of the eggs in the conductivity tube is only
abnormal in respect to time (1.e. the cleavage divisions are quite normal
but occur at a varying time after those in a control), it may be concluded
that the sequence of events in the two cases is the same.
A more important limitation lies in the fact that the resistance can
only be determined by concentration of the eggs. We may conclude
that when the eggs are concentrated at the bottom of the tube, their
development very quickly becomes delayed until the return of normal
conditions ; hence it is not possible to take a large number of readings
during one experiment.
These two factors would account for the variation found in curves
obtained from the individual experiments. For example, most of them
show the same maximum and minimum points during the first hour of
development, but corresponding points on different curves do not agree
in point of time. Again, it is almost certain that the primary rise in
conductivity due to the entrance of the sperm, lasts only for some fifteen
minutes or less ; if therefore it is found impossible (for technical reasons)
to determine the resistance of the fertilized eggs during this period, the
pronounced minimal point which exists during the first ten minutes of
development is entirely lost, and the curve differs radically in appearance
from the normal. Owing to the rapid rate in the rise and fall of the
conductivity at the commencement of development the exact time
at which the resistance is determined is of considerable importance. For
example, one experiment gave the following data :—
The resistance of eggs 3 mins. after fertilization was 10°5 ohms less
than that of the unfertilized eggs.
a » 9 ,, acter fer. was 12.5 ohms less
39 b] 39 13 99 be) 99 5) 99 bP)
>) 99 bb) 25 3) 99 >) 8 bi) >}>)
In other words, the conductivity of the eggs has undergone profound
changes within 13 minutes. It is therefore necessary to discover the
position of the maximum and minimum points with considerable accuracy
before any quantitative value can be ascribed to the changes in con-
ductivity which take place during the development of the normal egg.
ELECTRICAL CONDUCTIVITY OF FERTILIZED AND UNFERTILIZED EGGS. 49
Without wishing to dogmatize in any way as to the explanation of these
preliminary experiments, it may be pointed out that they may possibly
be due to either purely physical or purely chemical changes in the egg—
or to a combination of such causes. The egg in the unfertilized state is
remarkably impermeable to electrolytes, and can almost certainly be
regarded as being enclosed within a semi-permeable membrane. In its
unstimulated condition, this surface must necessarily be polarized. If
now this polarization be destroyed, the membrane must become more
permeable to ions than before. On this view the entrance of the sperm
effects the depolarization of the plasma-membrane. After about fifteen
~minutes this membrane must become polarized again, but the mechanism
whereby this is effected is not at present clear.
On the other hand, if the sperm carries an enzyme into the egg, which
acts on some constituent of the ege-cytoplasm, then a rise in conductivity
may occur as the result of the liberations of ions from unionized sub-
stances ; while a reversal of this reaction will have an opposite effect.
It is hoped that further work will produce sufficient evidence to show
which of these two possibilities is the more probable explanation of the
experimental data, and a discussion of the results obtained by other
workers is therefore postponed.
The expenses of this work have been partly defrayed by a grant from
the Government Grant Committee of the Royal Society.
[ 60 |
Some Rare and Interesting Sea Anemones from
Plymouth.
By
Chas. L. Walton and Olwen M. Rees, B.Sc.,
University College of Wales, Aberystwyth.
With Figures 1 and 2 in the Text.
THE anemones described in the followmg pages were collected by Mr.
J. H. Orton, and forwarded for examination.
I. Edwardsia timida, Quatrefages.
Quatrefages obtamed his specimens at Chausey, Manche, N. France,.
and his descriptions of #. tumida and E. harassi as new species appeared
in 1842 (‘‘Ann. des Sci. Nat.” (2), XVIII). G. Y. Dixon obtained eight
specimens at Malahide, Co. Dublin, and these he carefully described in
1886 (* Proc. Roy. Dublin Soc.”). He also united Quatrefages’ two species
as HL. tumda. In 1889 A. C. Haddon supported Dixon’s opinions and
identification, gave a good figure of the mesenterial muscle characters,
and contrasted these with three other British species (‘‘ Proc. Roy. Dublin
Soc.’’).
Through the kindness of Dr. E. J. Allen and Mr. J. H. Orton, B.8c.,
we have been able to examine and identify a specimen from Plymouth
Sound, obtaied May 22nd, 1912. This specimen was examined when
alive, when killed expanded, and also anatomically by means of trans-
verse sections.
Size.—Measurements during life were difficult to obtain as the Anemone
was very timid and remained buried in sand, only expanding the ten-
tacular crown at the surface. The latter was 12 mm. m diameter.
When killed in an expanded condition, the total length was 41 mm. ;.
length of capitulum 9 mm., diameter 3-5; diameter of scapus 4 mm.
Form.—Physa not large, and when partially invected showed eight
well-marked divisions; no attached sand grains. Scapus elongate,.
cylindrical, tapermg below and somewhat inflated at the summit,
covered by a thin coat of mucus and a number of attached sand grains ;,
body-wall slightly wrinkled transversely and divided into eight regions.
SOME RARE AND INTERESTING SEA ANEMONES FROM PLYMOUTH. 61
by the grooves along the insertion of the mesenteries ; there is a tendency
to folding, and suckers are present on the upper portion. The capitulum,
arising from the scapus by a gentle slope, was retractile, delicate, and
smooth. Disk concave; mouth raised on a cone. Tentacles 16 in
number, of fair length and somewhat obtuse ; at first sight there ap-
peared to be 17 tentacles, but this was due to the fact that one was
bifurcate near the summit.
Colour.—Investing coat yellowish ; during distension, the mesenteries
showed through the integuments as white longitudinal lines. Disk hight
brown, freckled with yellowish white spots, the eight radii yellowish white
with a dark central line ; lips of a darker shade of brown than the disk
and with a circle of eight reddish brown spots. Tentacles pellucid,
freckled, and indistinctly and irregularly barred and blotched with white,
and with a few distinct madder-brown or chocolate spots, which tended
to become bars near the tip: at the base of one of the tentacles was a
white spot. The colouration of the disk and tentacles harmonized so
exactly with that of the sand amidst which the Anemone was living as
to render it by no means easy of detection, even when fully expanded.
Anatomy.—Transverse sections showed muscle characters practically
identical with those figured by Haddon. The ectoderm is thin, and
broken in many places; the mesogloea is fairly thick, not very dense,
and contains here and there lenticular spaces of no great size; these
stain deeply. The endoderm is of about the same thickness as the
mesogloea, and both broaden in the regions between the insertion of the
mesenteries.
The specimen was a female, and the mesenteries were all gonophoric.
In the basal muscle the mesogloea shows eight to ten folds on either side,
many of them branched ; the longitudinal muscles large and with from
eighteen to twenty folds, a number of which are more or less branched ;
all are friged, givmg them much the aspect of fern fronds. The ova
occurred as more or less compact masses.
II. Edwardsia claparedi, Panceri, 1869.
Haddon (1889) suggested that the Edwardsia which Kingsley found
washed up at Torquay in 1854, and which was described by Gosse (1860,
p- 262) as “% Hdwardsia beautempsi (Quatref.),’ may have been
E. claparedi. After stating his belief that HE. callimorpha, Gosse, is
identical with E. beautempsii, Quatrefages, Haddon enumerates the
points of difference between that species and the specimen in question as
given by Gosse, and concludes : ‘“‘ In the above particulars this Edwardsva
62 CHAS. L. WALTON AND OLWEN M. REES.
agrees so well with the description and beautiful figures of E. claparedé.
(Panceri) given by Professor Andres (Le Attinie, p. 90, pl. xi.) that we
may with justice, for the present, allocate it to that species.”
After examination and comparison of both external and anatomical
characters, we are able to identify as H. claparedi two specimens from
Plymouth ; and the species can thus be added to the British Fauna.
with certainty.
Of the two specimens just mentioned, one (A) was kept alive for a
considerable time at Plymouth, was safely sent to us at Aberystwyth,
and remained in a healthy condition, living buried in sand in a shallow
dish. When first received it was very timid and remained buried for
twenty-four hours, expanding at first only by night, and closing rapidly
at the least vibration. Later it would remain expanded during daylight
and for much longer periods, and it also became much less sensitive to
movements in its vicinity. Both specimens were obtaimed from Jenny-
cliff Bay, Plymouth Sound.
Size.—It was impossible to obtain complete measurements of (A)
during life, as it remained buried, and if uncovered retracted and at
once commenced to bury itself by the use of the physa. When partially
anesthetized the total leneth was 50 mm.; greatest diameter of scapus
75mm. ; of capitulum 4mm. ; the physa was 4 to 5 mm. in length and
breadth ; and the expanse of the tentacular crown 12 to 13 mm. The
physa was rounded, delicate in texture, and almost transparent. Scapus
cylindrical, fairly stout, tapering downwards to just above the physa,
ringed and folded during partial retraction ; grooved by the insertion of
the mesenteries, with the intervening ridges warted. Scapus covered
by a thin cuticle which is thickest on the ridges and about the warts ;
these latter occur in a linear row on each ridge and are seldom contiguous ;
the upper third of the scapus is bare of cuticle and the warts are fewer
and finally disappear. The capitulum and upper portion of the scapus
can be retracted within the remainder of the scapus, and this movement
can be very rapidly effected. The tentacles are sixteen in number, slender,
tapering, about twice as long as the diameter of the disk ; held in a most
irregular manner as a rule, some extended, others flexed, others bent in
a contorted manner across the disk; occasionally all are regularly
extended, the tips bent inward (as shown in Fig. 1).
Colouwr.—Physa almost transparent. Cuticle rust-red, but darker
where thickest (as around the warts). On the summit of the warts the
cuticle is frequently missing and they then appear as pale spots. Capitu-
lum dull opaque flesh colour, near the summit is an indistinct white
SOME RARE AND INTERESTING SEA ANEMONES FROM PLYMOUTH. 63
ring, and above this an indistinct circle of purple. Disk fawn, with some
orange mottlmgs about the mouth region; an indefinite white area
runs from the base of the two opposite “ gonidial ”’ tentacles toward the
lips, and from the bases of the remaining six tentacles of the primary
cycle run similar indistinct black bars, these radial markings divide the
rest of the disk into eight more or less irregular fawn-coloured, triangular
areas ; the mesenteries also show as pellucid white lines. Mouth usually
Fic. 1.—Edwardsia claparedi. Oral disk (greatly enlarged).
elevated, lips pale. Tentacles translucent, blotched with opaque-white
and speckled with small red dots, the tips white: the white mottlings
appear mainly on the front face.
Specimen (B).—A preserved example, obtained from mud, Jennycliff
Bay, April 12th, 1912. It was strongly contracted, and somewhat
damaged. Cuticle thin and brownish in colour, the mesenteries showed
here and there through the body-wall in an indistinct manner ; capitulum
and physa invected ; eight warted ridges were present, but not so strongly
developed as in the last example. Length 28 mm., breadth about 8 mm.
64 CHAS. L. WALTON AND OLWEN M. REKES.
We have compared these Plymouth examples with preserved speci-
mens of #. claparedi obtained from the Naples Marine Biological Station,
and find both external and imternal characters in agreement. The
following is a short description of the external characters of one of the
best of the Italian specimens :
Length (somewhat contracted) 45 mm., greatest diameter 5 mm.
Physa small, being slightly contracted, about 1-5 mm. in length. Scapus
Fic. 2.—Edwardsia claparedi. Part of transverse section through the scapus regio
showing tubercles, body wall, and mesentery (slightly diagrammatic). ndea to lettering :
cu, cuticle; ec, ectoderm; en, endoderm; m, mesoglea; m.f., mesenterial filament ;
/, foreign incrustations on the body-wall ; sp., space at summit of tubercle; p.m., pariet a
muscle ; 7.m., longitudinal retractor muscle ; fw, tubercle; z, zooxanthellae.
cylindrical, tapering at either extremity, coated by a wrinkled, orange-
coloured epidermis, and beset with eight longitudinal rows of whitish
warts, devoid of covering at their summits; they are set more closely
SOME RARE AND INTERESTING SEA ANEMONES FROM PLYMOUTH. 65
together on the upper third, but scarcely ever contiguous. Disk narrow,
mouth pouting. Tentacles 16, obtuse, wrmkled, contracted to a length
of 3 mm.
All specimens likewise agree with the figures and description of Andres,
and the plate given by Delage and Hérouard in Zoologie Concréte. The
colouration of this species is evidently extremely variable to judge by
the figures and descriptions of Andres in L’ Attinie.
Anatomy.—Transverse sections of the two British and an Italian
example revealed practically identical characters. (B) was strongly
contracted and somewhat injured and gave very indifferent results
when sectionized. Sections showed. the cuticle and a thick but irregular
ectoderm (Fig. 2); the mesoglcea of the column wall is comparatively
thin in the capitular region, but becomes very dense and much thicker
toward the physa end; the warts consist of outgrowths of the mesogloea
and are frequently hollow, being then capped by a thin layer of mesoglea
and ectoderm. All eight mesenteries are fertile; the retractor muscle
is large and the basal muscle comparatively small in the region bearing
the gonads ; lower down, the retractor becomes smaller, and the basal
muscle larger, and in the region of the physa the two are of about equal
size. The folds of the basal muscle are about twenty in number on each
side and are often bifurcated, the proximal fold gives off numerous small
branches on its outer edge ; the folds are long and slender and lie practi-
cally at right angles to the central strand of mesogloea, which appears in
section as a fairly stout rod, branching out at its distal end. The longi-
tudinal retractor muscle is reniform in section, but the folds are not as
stout nor have they the peculiar moss-like appearance seen in E. témida ;
they are fairly slender, very much branched, and are from fifteen to
twenty in number. We are indebted to Mr. F.S. Wright for a figure of
this Anemone in the living condition (Fig. 1).
fo)
Ill. Haleampa chrysanthellum, Peach.
Originally described by Peach and Gosse from Cornish specimens,
and regarded as the only British species until Haddon discovered
H. arenarva in 8.-W. Ireland in 1885 and 1886. As the two species bear
a considerable external resemblance it is more than likely that there
has been some confusion in identification. Haddon identified specimens
from the East of Ireland as H. chrysanthellum, with certain anatomical
characters, but he pointed out that, until specimens from the original
Cornish localities had been examined anatomically it would be unsafe
NEW SERIES.—VOL. X. NO. 1. NOVEMBER, 1913. E
66 CHAS. L. WALTON AND OLWEN M. REES.
to assume actual identity. If the Cornish form should prove to be
identical with the Irish specimens considered to be H. chrysanthellum
by Haddon, well and good; it is also possible that H. arenaria has a much
wider range. Meanwhile many identifications can only be accepted
provisionally. British records of H. chrysanthellum include: Fowey
(Peach); Gwyllyn Vase, Pennance, etc. (Cocks); Salcombe (Allen and
Todd); River Yealm (‘‘ Plymouth Marine Invertebrate Fauna’’) ;
Isle of Man (Herdman); East of Ireland (Haddon); Firth of Forth
(Leslie and Herdman), etc.
In 1907 one of us examined some twenty living specimens of Halcampa
collected in the River Yealm. Considerable variability was noted as to
incrusting sand, the retractility and size of the physa, and the colouration.
Lack of time unfortunately prevented any further inquiry on that
occasion. Recently, however, three preserved specimens collected in
the Yealm were examined and found to agree in all external features.
Sections have been cut, and the anatomical characters compared with
Haddon’s figures of his East Irish specimens and found to be identical.
It is noteworthy that both Haddon and Gosse state for this species that
the physa is large and non-retractible, and this character should prove
to be a useful aid to identification. The following is a description
of the external characters of the specimen examined anatomically
(preserved in spirit): Total length 20 mm., divided as follows: physa
3-5 mm. long and 3-5 mm. broad, scapus 13 mm. x2 mm., capitulum 3-5:
Physa globular, delicate, semitransparent, studded with small white
suckers to which adhered numerous sand grains; Scapus slightly wrinkled;
Disk convex, elevated, M-mark on the margin distinctly visible.
In another specimen 31 mm. in length the physa was similar in form
and showed the same numerous small white suckers and attached sand
orains.
IV. Haleampa arenaria, Haddon.
This species was described by Haddon in 1886 from specimens obtained
from the Kenmare River, S.W. Ireland, 38-44 fathoms (1885), and
again, mouth of Bantry Bay, 38 fathoms (1886). We are indebted to
Mr. J. H. Orton for a specimen from Rum Bay, Plymouth Sound,
November 19th, 1910. He further provided us with some interesting
sketches made while the anemone was alive. In his opinion this specimen
was H. arenaria, and our anatomical examination has proved this to be
correct. The following notes describe the specimens after preserva-
tion. Total length 38 mm., greatest diameter of scapus 4-5 mm., of
SOME RARE AND INTERESTING SEA ANEMONES FROM PLYMOUTH. 67
capitulum less. Body-wall thick, tough and opaque ; physa damaged,
but appears to be much smaller than in H. chrysanthellum, no sand
grains were attached, and no suckers were observable with a lens; the
small size is well shown in Mr. Orton’s sketches, as is also the fact that
the physa is retractible in this species, and thus agrees with the plate
and description of Haddon (Proc. Roy. Dublin Soc., 1889). The scapus
tapers at either extremity, and for a length of 20 mm. is coated with sand
erains attached to suckers, and within this portion the physa and
capitulum can be withdrawn. The capitulum is smooth, more delicate,
and somewhat constricted near the summit.
Colour, pale yellowish buff, the mesenteries showing indistinctly as
paler lines. Tentacles and disk much as in H. chrysanthellum ; one of Mr.
Orton’s sketches, comprising a tentacle and portion of disk and mouth,
shows the transverse bars,. M-mark and the triangular brown patches
figured by Haddon ; but the form of these brown marks on the disk is
different. the marks are triangular, with
the apex directed toward the tentacle.
Instead of being “ lenticular ”’
Haddon gave a comparison of the anatomical characters of the two
species of Halcampa, but a re-statement of the points of difference seems
advisable ; and ignoring for the present the colouration of the disk and
tentacles, the details are here given :—
H. arenaria.
(1) Physa probably
HT. chrysanthellum.
(1) Physa large, globular, trans- smaller,
lucent, provided with small white
suckers, and not capable of being
withdrawn within the scapus.
(2) Scapus smooth.
(3) Number of folds of the
muscular epithelium of the longi-
tudinal muscle of the mesenteries,
as seen in transverse section, 10
to 12.
without suckers, and retractible
within the scapus.
(2) Scapus with suckers to
which adhere sand fragments
forming a more or less dense
covering.
(53) Number of folds of longi-
tudinal muscle about 15.
In addition to the above Haddon states that :—
(4) “ The oesophagus in section
is, relatively to the diameter of
the body, much larger in H. chry-
68 CHAS. L. WALTON
santhellum than in H. arenaria.”’
This character is, however, not
well marked in our sections.
(5) Also, “In H. chrysanthellum
only 6 mesenteries bear generative
products.” This is the case in
our specimen.
AND OLWEN M. REKS.
(5) “All 12 mesenteries are
fertile in H. arenaria.”
In the specimen we have exam-
ined only 10 perfect mesenteries
are fertile, those that are barren
being those mesenteries of the per-
fect lateral pairs which are nearest
to the sulcar directives (the sulco-
sulcar laterals of Haddon)
V. Eloactis mazeli, Jourdan.
In 1892 Garstang described a living specimen of this mteresting
Anemone from the Devonshire coast (Trans. Devon. Assoc.). Since then,
more or less mutilated specimens have been dredged by the s.s. Ovthona
from the Inner and Outer Rame-Eddystone trawling grounds; and
during May, June, and July, 1912, in particular, a number of examples
were brought in. Almost all were much damaged, only the summit of
the scapus and oral crowns being present, and these greatly distorted and
contracted. Under these conditions, the tentacles bemg much shortened
and strongly capitate, and the colouration very pale, it was only quite
recently that their true identity was recognized. Several when examined
still showed signs of life. As in the case of Hdwardsia claparedi we have
compared the Plymouth examples with named material from Naples
both as regards external and anatomical characters. The mutilation is
evidently due to the habit of lying buried in sand, the oral crown
projecting, and thus being cut off by the dredge.
The following is a description of one of the least damaged specimens :
Form.—Upper portion of scapus firm and smooth, but with many fine
longitudinal ridges and grooves, succeeded by a fosse. Tentacles 20,
set in two cycles of 10, long and short thus alternating; they consist
(in this contracted state) of a stout, transversely wrinkled stalk and a
strongly adhesive rounded head. Disk very tumid and much wrinkled ;
mouth rather large, one strong cesophageal groove. Colour.—Flesh tint,
the tentacles marked with brown near the summit; disk orange-pink
with somewhat lighter rays. Diameter of disk and tentacles 4 cm.
when strongly contracted. Locality, 53 miles off Rame Head; 25
fathoms, fine sand ; taken in fine-mesh dredge.
SOME RARE AND INTERESTING SEA ANEMONES FROM PLYMOUTH. 69
Mr. Orton sends the following notes regarding a specimen obtained
from the Outer Rame-Eddystone, July 2nd, 1912: ‘‘ The tentacles were
blotched with brown at the extremity, and several had double purple
internal stripes ; others appear to have only one coloured stripe ; body-
wall orange ... the tentacles were examined but no knobs were
visible.”
A more detailed description of this species will be found on pp. 70-80.
[ 70 ]
On Eloactis mazeli.
By
Olwen M. Rees, B.Sc.,
University College of Wales, Aberystwyth.
With Figures 1-4 in the Text.
JOURDAN was the first to describe Hloactis mazeli. In 1880 he published
Recherches zoologiques et histologiques sur les Zoanthaires du golfe de Mar-
seilles (1), and in this paper H. mazeli is described under the name of
Ilyanthus mazelii. Jourdan obtained his specimen from the muddy
sand of the north-eastern part of the Gulf from a depth of 60-80 metres.
He compares its external characters with those of Peachia, Ilyanthus,
and Halcampa ; the following is a translation :—
“In form it approaches Peachia, from which it differs through the
absence of gonidial tubes. In the absence of terminal pores and in the
smoothness of the column it resembles Ilyanthus, while its cylindrical
form recalls that of Haleampa, though it differs from this genus in that
it lacks tubercles and a terminal swelling. Its buccal disc is conical, of
an orange tint striped with darker lines which run from the mouth to the
bases of the tentacles. These last are twenty in number and are arranged
in two cycles; they are white with brown apices and the inner ones are
smaller than the external ones.”
“The column is cylindrical, and is orange-red with paler lines which
run down from the summit in the spaces intervening between the outer
tentacles. The basal region is lighter in colour and more membranous ;
it is non-adhesive, and the lower part of the column wall is often pushed
in, giving the base the appearance of being sunk in. Longitudinal and
transverse sections of the basal region show that this sunken portion has
no aperture.”
Jourdan could not study the structure much owing to the state of
preservation of his one specimen, also he was working in the early days
of the serial-section method. He was therefore unable to make out the
arrangement of the mesenteries, and thus could not place the animal in
its correct systematic position.
In 1884 Andres, in Le Attinie (2), gave the following description of
ON ELOACTIS MAZELI. Te
E. mazeli, placing it in the Heteractiniz with Eloactis globosa, Ropalactis,
Ragactis, Heteractis, and Stauractis.
The base, he says, is “ slightly adherent, often with a rounded vesicle
resembling a physa. Column long, cylindrical, suleated by 20 invec-
tions of slight depth, often minutely rugose; membranous, delicate,
scarcely adhesive. Disk small. Tentacles few, bicyclic 10:10; the
length of the tentacles of the external cycle twice that of the tentacles
of the internal cycle ; not entirely retractile, rounded at the tips; out-
wardly deflexed. Peristome low, rounded, concave and grooved. Mouth
often prominent. No acontia. Gonidia somewhat open. Pharynx often
protruded and resembling numerous angular lobes. Size fairly large.” ...
Delage and Hérouard (6), in 1901, described Eloactis mazeli thus :
Eloactis is an Actinian which appears to vary in form because of its
marked contractility ; the base is only slightly adherent, if at all; the
column is smooth or rugose according to the state of contraction; it
is deeply grooved longitudinally ; the tentacles are few in number and
arranged in two cycles; they terminate in a rounded swelling rich in
nematoblasts ; there is no sphincter.
Delage and Herouard also place it in the Heteractide (Andres) Heterac-
tine, 11th family; but they say that the family is probably highly
artificial, uniting provisionally several Actinians, concerning the anatomy
of which very little is known. They all have a smooth and striated but
not verrucose column, and tentacles arranged in various ways, but not
branched, and armed by swellings rich in nematoblasts.
In 1892, Garstang described a living specimen of this interesting
anemone from the Devonshire coast (Trans. Devon. Assoc.). Since then
several specimens have been dredged from the neighbourhood of the
Eddystone and the South Devon coast (cf. p. 68). Almost all were
damaged, only the summit of the scapus and oral crown being present,
and even these were greatly distorted and contracted. Under these
conditions the tentacles were much shortened and strongly capitate ;
the coloration of these specimens was usually of little intensity. Some of
the specimens still showed signs of life.
The present paper embodies the results of an investigation of speci-
mens dredged off South Devonshire, and of one perfect specimen from
the Mediterranean. It is sought—
(1) To establish the identification of the British specimens as speci-
mens of #. mazeli (Jourdan).
(2) To demonstrate the affinities of Eloactis with certain other
Actinian types.
72 OLWEN M. REES.
External Characters of E. mazeli (Jourdan).
The following description of the external characters of EH. mazeli
(Jourdan) is based on an examination of a preserved specimen from
Naples. Length of scapus, 47 mm.; it tapers gradually downwards.
Diameter at summit of scapus, 11 mm.; diameter at base, 7mm. The
base, which is slightly enlarged, is very similar to that of Peachia, being
invected somewhat in the centre to a depth of several mm. Upper
margin well demarcated, surface of scapus without tubercles, but very
much folded and wrinkled and thrown into numerous complex ridges.
Tentacles, 20 in two alternating cycles of 10 each, the outer the longer.
In this specimen they are contracted, rather stout, tapering slightly
upwards and then expanding into a globular or ovate head. Length of
outer tentacles 10 mm., inner 4 or 5 mm. Colour, greenish white (in
spirit). The tentacles are mottled with dark purplish brown blotches.
These become larger and confluent higher up, and in the contracted
tentacles appear as slightly raised vesicles or blisters. On the head
of the tentacle these marks are of a paler brown suggestive of a less de-
gree of contractility. The disk is narrow and concave; the mouth
pointed and prominent.
Internal Structure of the Italian Specimen of E. mazelv.
The mesenteries are twenty in number, and are all perfect and fully
developed. Their arrangement is very simple, the mesenteries arising
in pairs and two of these pairs are directives (Fig. 1). The longitudinal
muscles of each pair are on the faces which look towards the intra-
mesenterial spaces, except in the case of the four directive mesenteries
whose longitudinal muscles are on the faces which are turned towards
the adjacent intermesenterial spaces. There is only one siphonoglyphe,
and this is deep and well defined. The surface of the stomatodeum
possesses numerous ridges which increase the digestive area. The body
wall consists of ectoderm, mesoderm, and endoderm in almost equal
proportions. The ectoderm has a corrugated appearance on its outer
surface owing to the body wall being slightly contracted. The mesogloea
is fibrillar, especially towards the inner surface, as in Halcurias.
Jourdan, in his description of the internal characters of Eloactis, also
shows the fibrillar nature of the mesoderm : “ Sur les coupes transversales
le picrocarmin colore vivement le mesoderme et permet d’y distinguer
deux zones, l’externe composée de tissu conjonctif lache, interne formée
de tissus lamineux” (“In transverse sections, the mesoglea is deeply stained
ON ELOACTIS MAZELI. ho
Fic. 1.—Transverse section through the column, showing stomatodzeum with ceso-
phageal groove, and septostomes in all the mesenteries except in the sulcar directive and
in two sulco-lateral mesenteries: d. directive mesenteries, ws.gr. cesophageal groove or
siphonoglyphe, p.m. parietal muscle, 7.m. retractor muscle, s. sulcus, s.p. septostomes,
st, stomatodeum.,
74 OLWEN M. REES.
by picrocarmine showing two zones, the outer composed of loose conjunc-
tive tissue, and the internal zone of laminated tissue”). The mesoglea,
however, cannot be said to be in two zones, although the inner portion
is seen to be more fibrillar than the outer. Then endodermal cells have
a eranular appearance owing to the presence of zooxanthelle, which are
very numerous near the free surface. Towards the mesoglea the endo-
derm seems to become much weaker, the cells becoming spongy and
containing no algal cells. In fact, there is a tendency to form an endo-
dermal canal. The whole body wall is comparatively narrow, and very
compact, with no lacune and no inclusions, and also no nematocysts.
It is to be noted that nematocysts are present in the outer portion of the
ectoderm of the body wall of Halcurias. The parieto-basilar muscle is
very much more elongated than in the Edwardside, and is somewhat
like a hart’s tongue fern leaf, the midrib being very stout and giving off
short much-branched lateral veins on either side. The retractor muscle
is pear-shaped and there are between 26 and 30 slender, much-branched
folds. Each muscle fold on careful examination shows a definite central
strand, as in the folds of Edwardsia tumida, with an irregular layer of
tissue on either side, so that the whole fold has a similar appearance
to that of #. timida. The folds of Eloactis are, however, more slender
than those of £. timida, and the whole longitudinal retractor muscle of
E. mazeli resembles that of Peachia hastata. In P. hastata, however,
the retractor muscle is rather more elongated in section. The muscle
folds are numerous and more slender, and the whole is not so distinctly
marked off from the parieto-basilar muscle. In the region below the
stomatodzeum the parieto-basilar muscle becomes much shorter and
the muscle folds are longer and less arborescent, while the distinction
between the parieto-basilar and the retractor muscles is more indefinite,
and the muscle folds become numerous and more slender. The mesentery
is continued at its distal end into a mass of sterile tissue, the cells of
which contain zooxanthelle. A very thin filament of mesogloea is con-
tinued through the centre of the sterile mass, and in places this filament
opens to form small bulbs with cells of zooxanthelle. All the mesenteries
give rise to this sterile tissue. This suggests that in a fertile specimen all
the mesenteries would behave alike and would thus give rise to twenty
gonads. In Halcurias also all twenty mesenteries are fertile. There is
one cesophageal groove as in Halcurias, but in Hloactis mazeli the groove
is deep and well defined; whereas in Halcurias the siphonoglyphe is
said to be neither very deep nor well defined. In #. mazeli the ectoderm
of the siphonoglyphe consists of large elongated columnar cells containing
ON ELOACTIS MAZELI. 75
Yip
Hi
=
iin
=
CD
LY
eB
SS Bed BS ow Pa
ent AT
Fig. 2.—Transverse section through a mesentery, showing the muscles, also the struc-
ture of the wall of the stomatodeum and of the wall of the esophageal groove : ec. ecto-
derm, en. endoderm, m. mesoglea, m.f. muscle fibres, @s.gr. cesophageal groove or
siphonoglyphe, p.m. parietal muscle, 7.m. retractor muscle, 7./. nerve layer, z. zooxanthell,
aw.st, wall of stomatodzeum.
76 OLWEN M. REES.
large nuclei, and they are slightly granular and ciliated. Between the
ectoderm and mesogloea is a very delicate layer containing the nerve:
cells. The mesogloea in this region is denser and more uniform than that
of the body wall, and it is not fibrillar.
The ectoderm of the stomatodeum is distinctly corrugated. The
cells are large, and many of them contain colonies of zooxanthellae. The
whole wall of the cesophagus is thrown into ridges like those described
and figured by McMurrich in his description of Halcurias (3). A trans-
verse section through the lower region of the column shows the body
wall with twenty short mesenteries, each consisting only of an elongated
form of the parieto-basilar muscle. Longitudinal sections of the oral
disk were examined. The ectoderm is spongy and contains a few colonies
Fic. 4.—Transverse sections through a tentacle, showing structure of wall: (a) near
the tip, (b) near the base ; ec, ectoderm, en. endoderm, m. mesoglea, m.f. muscle fibres,
m2. nematocysts, 7.J. nerve layer, z. zooxanthelle.
of zooxanthellae. No nematocysts are present. The mesogloea sends up
folds into the ectoderm, except at the points where the mesenteries are
attached to the disk. The endoderm contains a few scattered cells of
zooxanthelle. From longitudinal sections of a tentacle (Fig. 3) it is seen
that the ectoderm is very thick at the tip, and contains numerous nema-
tocysts. In this region zooxanthelle are almost absent. This ectoderm
causes the swollen tip of the tentacle (Fig. 4a). Lower down the
zooxanthelle become more numerous (Fig. 4b), and are seen in the
ectodermal cells as colonies of pigmented bodies of a greenish yellow
colour. The presence of these algal colonies accounts for the blotches
described on the exterior of the tentacles. Near the base the ectoderm
is less thick, and in places contains neither nematocysts nor
77
ON ELOACTIS MAZELI.
endoderm, mm
s, n. nematocysts, 2./, nerve layer, z. zooxnathelle.
0 a 2
i — ' E. 3
1 aa Ta ae ak 3
ao : ah % Resa ace Tis Os
SCAN AH ICAL eS pe ae a acon Ollie
ch a tentacle:
i\i an =a TERE ee Sra
Rorss
3.—Longitudinal section throu
Fic.
mesogloea, m.f. muscle fibre
78 OLWEN M. REES.
zooxanthelle. There is a definite nerve layer at the base of the
ectoderm in the region around the tip where there are numerous
nematocysts to control. The mesogloea is dense, but becomes more
fibrillar towards the base, where it also sends out branches which
very often divide. Near the base also the nerve layer becomes much
thinner.
Septostomes or Mesenterial Stomata.
“Tn the genus Actinia these stomata are found in the uppermost inner
angles of the complete mesenteries close beneath the mouth, and are
probably the result of incomplete union of the mesentery with the
stomatodeeum.”’ This is how they are described by Professor Bourne in
(5). They are known as internal stomata. In some other Actinie,
e.g. Tealia corvacea (crassiccrnis) and Metridium dianthus, external
stomata are present. These are openings situated in the upper third of
each mesentery between the longitudinal and the parietal muscles.
In Metridium septostomes are found on many of the imperfect as well
as on the perfect mesenteries, though there are no septostomes on the
directive mesenteries. Both internal and external septostomes are
present in some anemones, e.g. Hertwig says of the Actinian which he
named Dysactis crassicornis, “Two kinds of stomata are found on the
muscular part of the septa—the peristomial or external stomata are
very large, whilst the marginal which lie close to the wall are small.”
These septostomes are also found in the primitive anemones, e.g. Hal-
campa chrysanthellum possesses external stomata. No septostomes
were found in any of the Edwardside. External stomata are present
in all the mesenteries of Eloactis mazeli, and each takes the form of an
elongated sht down the mesentery separating the retractor muscle from
the parietal muscle. These stomata provide a means of communication
between the radial chambers separating the mesenteries, and probably
thus ensure a better method of circulation. Again, undoubtedly they
facilitate rapid retraction, for without the septostomes there would be
a danger of the mucilage, etc., present in the radial chambers of the
coelenteron getting clogged in the uppermost parts, whereas the presence
of the septostomes provides free passage from one chamber to another,
not only by way of the axial space into which they all open, but also
via these stomata.
Systematic Position of Eloactis mazelv.
Delage and Hérouard (6) have temporarily placed this anemone in
ON ELOACTIS MAZELI. 79
the 11th family of the Heteractine with several other anemones whose
internal structure is unknown.
The elongated form of the body, the absence of a definite sphincter
muscle, and the presence of a small number of mesenteries, are characters
of Eloactis which show that it is related to the primitive, rather than to
the more advanced anemones: the latter do not possess an elongated
body, but are characterized by the presence of a definite sphincter muscle
and a large number of mesenteries. The Edwardside and the Hal-
campidee are two of the most primitive families whose members have an
elongated body form, no definite sphincter muscle, and a small number
of mesenteries. The Edwardside have eight mesenteries, whereas in
FE. mazeli there are twenty ; therefore Hloactis cannot be placed with
Edwardsia, the sole genus of that family.
The family Haleampide has been defined by McMurrich in the papex
already referred to (2), as ‘‘ Actiniee with a small number of mesenteries,
six, ten, or twelve pairs being all present ; longitudinal muscle pennons
narrow, but strong; no special sphincter muscle ; conchula present or
absent ; base usually rounded and vesicular.” In this family, therefore,
MeMurrich places Halcurias and Peachia as well as the genus Halcampa.
Eloactis, with a small number of mesenteries and no sphincter, may
be placed in the Haleampide. It may be closely compared with Hal-
curias pilatus, as described by McMurrich, and both are found to possess
the following characters :—
Column cylindrical ; ten pairs of mesenteries, all of which are perfect.
There is no special sphincter muscle, and the tentacles are not covered
after contraction.
There is one siphonoglyphe, and on the surface of the stoma-
todeum are numerous ridges.
All the mesenteries bear reproductive organs.
The mesoglea is fibrillar, especially towards the inner surface.
Halcurias has an adherent base, whereas the members of the Hal-
campide have a rounded and vesicular base. loactis mazeli and
Eloactis producta have indications of a slightly adherent base ; but in
these three forms this character is outweighed by the small number of
the mesenteries and the structure of their muscles.
The structure of #. mazeli shows that this form is slightly more highly
specialized than Halcurias pilatus. In the latter, the four pairs of mesen-
teries situated in the sulco-lateral and lateral intermesenterial spaces
are less extensively developed than the other six, and the siphonoglyphe
is neither deep nor well defined. On the other hand, £. mazeli has
80 OLWEN M. REES.
all its mesenteries fully developed and has a deep and well-defined
siphonoglyphe ; also the distribution of nematocysts is different in the
two forms. Eloactis possesses twenty highly specialized tentacles, all
well armed with nematocysts, and these are present only on the tentacles,
especially on their ovate heads. H. pilatus does not possess such highly
specialized tentacles; they are more numerous, and nematocysts are
present on the disk and body wall as well as on the tentacles. Thus
the tentacles are not so well adapted as feeding and defensive organs,
and the division of labour is not so complete as in FL. mazeli.
Peachia is probably still more advanced :—
It has a single deep siphonoglyphe like #. mazeli, but the longi-
tudinal retractors of the perfect mesenteries of Peachia are more elon-
gated (in section), and there is a better developed system of musculature
than in £. mazelv.
Eloactis mazeli is therefore an elongated anemone, with twenty highly
specialized tentacles, ten pairs of perfect and fully-developed mesen-
teries, and a deep and well-defined siphonoglyphe, and is probably
intermediate in position between Halcurias and Peachia.
BIBLIOGRAPHY.
1. JourpAn, E. Recherches zoologiques et histologiques sur les Zoanthaires
du Golfe de Marseille, 1880.
. ANDRES, A. Le Attinie, Vol. I. Fauna und Flora des Golfes von Neapel.
Leipzig, 1884.
3. McMourricu, J.P. Scientific Results of Explorations of the United States
Commission Steamer Albatross, 1887-1888. Report on Actinie.
4. Happon, A. C. A Revision of the British Actinie. Trans. Roy. Dublin
Soc., Ser. II, Vol. IV, 1888-1892.
5. LANKESTER, EH. Ray. A Treatise on Zoology, Part II.
6. DELAGE, Y., et HERovARD, E. Zoologie Concréte, Tome II, 2 A.
iw)
[ 81
Calliobdella lophii, Van Beneden and Hesse.
By
W. Harold Leigh-Sharpe.
On May 12th, 1913, four specimens of the marine leech (Calliobdella
lophw) were taken by myself whilst working at the Marie Biological
Association Laboratory, Plymouth. The leeches were parasitic on the
skin of a large angler (Lophius piscatorius), just behind the gill covers
and in front of the pelvic fins, two on each side. The angler was caught
in Jennycliff Bay within a few hundred yards of the shore, about 3.15
p.m., half-ebb, and was taken in a small trawl only just large enough to
contain it ; shrimps were present in the same catch, but no fish.
Calliobdella was previously unknown at Plymouth. The leech was
named by van Beneden and Hesse in 1863 from five specimens found in
March by Hesse at Brest.* Some of the external characters alone were
described by them. They omit to mention, however, that the genus
is characterised by its having six annuli to each body segment, a point
which it shares in common with Ichthyobdella and Pontobdella, but
which separates it from other genera. They describe so accurately the
beautiful appearance of this leech that their own words suffice :—
“An animal carrying a sucker at each extremity of the body, the
posterior very large and simple. The body divided into two distinct
regions, a neck region bare, and a region of the body properly so called,
this latter carrymg laterally rounded tubercles on the segments or
cutaneous folds.”
“This species attains a length of five or six centimetres.” (Two of
those captured at Plymouth were seven or eight without extreme exten-
sion.) ‘It lives on the angler (fishing-frog), Lophius piscatorius. The
body is elongated, slightly convex above, flattened below. The skin is
tough, with tubercles on the side, and divided into twenty-four segments,
of which ten or a dozen belong to the region of the neck, the others to
the body properly so called. The neck and the posterior sucker are
paler than the rest of the body ; the segments of the neck are covered
* © Recherches sur les Bdellodes ou Hirudinées, 1863.”
NEW SERIES.—VOL. X. NO. 1. NOVEMBER, 1913. 1
82 W. HAROLD LEIGH-SHARPE.
with minute black dots ; the body is of a clear brownish green, orna-
mented above with broken, parallel black lines. The body is paler
underneath, showing rose-pink markings in the form of a V. It is very
noticeable also that the last segment but one of the neck is ornamented
with an orange band which encircles it. The movements of this leech
are very lively.”
They were very lively in captivity, clmging firmly with the posterior
sucker to the jar containmg them, and seeking eagerly for some fresh
host with the anterior end.
They moved occasionally with the usual loop-like movements of a
leech, taking great care to place the posterior sucker as exactly as possible
in the position previously occupied by the anterior.
Calliobdella is sharply divided by a constriction into a neck and a
body. Blanchard,* who mentions this leech as occurring in the Mediter-
ranean, states that the segments of the body are formed of three to six
annuli according as the three primordial rings are more or less divided
by chorisis. All those in my possession have six annuli to the segment.
The same author suggests that the animal is flattened when young and
rounded when old. Further, he alters the name for orthographical reasons
to Callobdella.
On the body, but not on the neck, are lateral protuberances, eleven
pairs of hemispherical projections on each side of the animal, “rising
and fallmg as if by respiration,” as Dalyell} said of a leech he described
as *‘ Hirudo vittata,’’ and which possibly was the same. These are rudi-
mentary branchiz, corresponding to the large external branchie of
Branchellion, and similar to those of the North American and European
marine and fresh-water form, Cystibranchus.
According to Quatrefagest these appendages do not receive the blood
contained in the vessels, but only the lymph which becomes diffused,
and which makes the respiration truly lymphatic.
Ichthyobdella is without these tubercles, and Pontobdella, which is
further distinguished by its warty appearance also. Owing to the six
annuli of the segment being formed by chorisis from three, the first
respiratory vesicle is on the first double ring, the second on the fourth
double ring, and so on. The anterior half of each double ring carrying
the vesicle is spotted.
There are no eyes.
The extreme size of the posterior sucker in C. lophii, it being
* “ Hirudinées de l’Italie, Boll. Mus. Zool. Torino,” Vol. IX, 1894, No. 192.
T ‘* Powers of the Creator.” Dalyell. Vol. II, p. 9, 1858.
{ Ann. Se. Nat., Vol. XVIII, p. 322, 1852.
CALLIOBDELLA LOPHII, VAN BENEDEN AND HESSE. 83
more than twice the maximum breadth of the body, distinguishes this
species from the other (or others). Ludwig Johannson,* who describes
this leech as rare, admits that he has never seen one alive, and states
that the one in the museum at Stockholm was taken at Bergen in 1879,
also that it occurs on the coast of Norway, and the two specimens he
dissected were sent by a fisherman from Hels6 in 8. Bohuslin. He,
adopting the altered name Callobdella, characterizes the genus by its
possessing a large copulatory organ with a bursa and two seminal vesicles,
while in other genera the copulatory organ is without the latter.
* Johannson. ‘‘ Die Icthyobdelliden in Zool. Reichmuseum in Stockholm, 1896.”
[ 84 ]
Habit and Habitat in the Galatheidea:
a study in adaptation.
By
K. Zimmermann, B.Sc.,
University College of Wales, Aberystwyth.
With Figure 1 and Plates 1-4 in the Text.
THE heterogeneous assembly of Decapod Crustacean types classed as
29
““ Anomura”’ is well known to present a wide range of variation in
structural features ; in fact, the most apparent bond of union between
its highly dissimilar sub-groups consists in the still greater disparity
which exists between these and members of either ‘“‘ Macrura”’ or
“ Brachyura ” proper. The Anomura may best be compared with that
other heterogeneous group, the Amphibia: each, apparently of aquatic
ancestry, has suffered in the unequal contest with a highly specialized
offset from the parent-stock (Brachyura-Reptilia) ; the survivors of both
the ill-fated groups, Anomura and Amphibia, are few in number, varied
in type, and probably not closely related among themselves.
Among the Anomura, the sub-group Galatheidea present a fairly
connected natural assemblage of types. Study of this sub-group reveals
the presence of two distinct and widely divergent lines of specialization—
on the one hand, for life on shore (near or above low-tide mark), and, on
the other, for life in deeper waters. Thus the group comprises, together
with more or less intermediate forms, three well-marked types :
A. THE Galathea squamifera TYPE.
The characteristic species frequents the fairly open seas which sur-
round our coasts, and is rarely found near low-tide mark except for a
short time in spring; the form of body is almost Macrurous, and the
abdomen, though usually flexed, is relatively large, and of no little
importance In swimming.
B. Tue Porcellana platycheles TYPE,
The characteristic species lives well up in the muddier portion of the
intertidal zone, and is common about midway between high and low
HABIT AND HABITAT IN THE GALATHEIDEA. 85
tide marks. The form of body presents many peculiarities, both super-
ficial and in detail, comparable with those which are regarded as charac-
teristic of the Brachyura, furnishing an excellent example of “ con-
vergence.” . . . The abdomen is greatly reduced in size, the length of
the carapace scarcely exceeds its breadth, and the habit of clinging to
stones is developed to a marked degree.
C. THe Munida rugosa TYPE.
Characteristic of fairly deep waters (found at depths varying from
10 to 600 fathoms). The general form of body closely resembles that
of type A, but obvious specializations for deep-sea life exist.
Thus, within the group Galatheidea, a few species (those of group C)
have been driven by stress of competition in the shallower waters to seek
shelter in the deeper and more sparsely populated regions of the sea ;
but the main line of specialization in the group is in the direction A to B
—towards adaptation for life higher up the shore. It is the aim of this
memoir, by describing details of the structure of the branchial and other
organs of the Galatheidea, to show what peculiarities have arisen in con-
nection with the need for special precautions :
(a) For ensuring steadiness of balance when the animal is in pro-
gression or at rest within the wave-washed region of the shore ;
(b) For guarding against the choking of the branchial cavity and
clogging of the branchial organs by the mud of the low shore.
In doing this, an endeavour is made to arrange these details in logical
and progressive order, as indicating for the more crab-like members of
the group “ the base degrees whereby they did ascend.”
I. MoDIFICATIONS WHICH PROMOTE EFFICIENCY IN RESISTANCE TO
WAVE-WASH AND IN PROGRESSION ON THE SHORE.
It is convenient to use the type-species A (Galathea squamifera) as
a starting-pomt from which to trace various lines of specialization
within the group, this species being probably among the nearest to the
Macrurous ancestor. We find throughout the genus Galathea few special-
izations of a definitely Anomurous character: the long, rather narrow
carapace and powerful abdominal swimming “ tail”? with broad tail-fan
obviously mark the active swimmer. In those members of the group
which frequent the higher coast-zones—notably the Porcellanids—and
which thus assume the creeping rather than the swimming habit, we note
a reduction in importance of the Macrurous characters—a diminution
86 K. ZIMMERMANN.
in size of the abdomen, accompanied by a broadening of the carapace
and strengthening of the ambulatory thoracic appendages. The re-
duction of the abdomen is well marked in Porcellana platycheles, which,
as a general rule, does not swim, but moves from place to place in a crab-
hike sidling fashion. The abdomen, which is habitually carried tucked-up
beneath the thorax, is relatively very weak, and narrowly triangular in
outline, and the tail-fan, though still present, is reduced in size. The
abdomen is rarely unfolded except under special circumstances, as when
the animal is upset on to its back. In this case, the abdomen is flapped
vigorously, so as to raise the animal in the water and alter the inclina-
tion of the body, allowing it to fall back into the natural position, while
the chele are extended to catch at any means of support to which it
may be possible to cling. A similar action of the abdomen has been
observed in Cancer and Carcinus individuals, when subjected to similar
conditions, but in these two Brachyuran genera the absence of the tail-
fan renders the flapping less effective ; this deficiency, however, is not
of much consequence, as their superiority in weight and strength gives
Cancer and Carcinus a greater stability than is possessed by Porcellana.
Decapoda which frequent the shore have the carapace much broader
and flatter than i Macrura, and this has led to the sharp lateral folding
of the carapace, giving protection to the branchial organs ; this broaden-
ing is also of importance in connection with the above-mentioned habit
of sideway progression, as we generally find the long axis of any body
is turned in the direction of habitual movement. This method of advance
in another than the forward direction is peculiarly suited to animals
endowed with the Decapod Crustacean’s type of sense-organs and fre-
quenting obstructed places, and also to those whose walking limbs are
spread in the almost radial fashion characteristic of the Porcellanids.
The efficient clmging mechanism so afforded is based on the principle
which determines the radial spreading of tent-pegs with their ropes, and
of the several hooks of a grapnel, and has doubtless been developed in
connection with the habit (already marked in Galathea, and most pro-
nounced in Porcellana plaiycheles) of clnging to the under-surfaces of
stones, and thus resisting the force of wave-wash as well as that of enemies.
The radial arrangement of the limbs also endows the animal with facility
of movement in an oblique, as well as in the directly transverse, direc-
tion—a valuable asset to a dweller in the intertidal zone of shifting
pebbles.
In connection with the strengthening of the thoracic limbs of Porcel-
lana platycheles, we note in this species the greatest concentration of
HABIT AND HABITAT IN THE GALATHEIDEA. 87
the thoracic nerve-ganglia observed in any of the Galatheidea, the con-
dition almost approaching that which characterizes the Brachyura
(see Plate 1, Figs. A, B,C, D, E). The last thoracic leg (appendage XIII),
which in the Galatheidea is modified into a slender cleaning-organ, of
course does not participate in the clinging action or in locomotion, and
it is noticeable that, even in Porcellana platycheles, the ganglion of the
13th segment remains semi-isolated from the central mass formed by
the fusion of most of the other thoracic ganglia.
The marked clinging-habit of Porcellana platycheles should be con-
nected not only with the resistance to dislodging forces, but also with
the general protective “‘ melting into the background.” The body is
flattened, and when at rest is pressed closely against the rock—the
chelee are flattened and expanded in the horizontal plane, and are notched
so as to fit accurately against the front edge of the carapace—and the
whole dorsal body surface is coated with shaggy, grey, insensitive hairs,
nearly matching in colour the rock to which the animal clings (see Plate
2, D). In this connection we remark also the absence of those trans-
verse ridges of the carapace which are so conspicuous in more active
members of the group. These carapace ridges in Galathea are fringed
with hairs of a fairly simple, once-pinnate type (Plate 2, A, and Plate
4, B), whose continual agitation by the motion of the surrounding water
probably prevents the settlement of such unwelcome guests as Hydrozoa,
Polyzoa, etc., likely to retard the swimmer by increasing the friction-
surface. A sedentary form like Porcellana platycheles has no such in-
terest in avoiding encrustation—and in it we find no trace of ridges or
of waving hairs, the shaggy hairs of the dorsal surface being too close
and coarse to be easily agitated by movement of the water. Again, the
ridges, if present, would inevitably detract from the general protective
resemblance to surroundings, and from this standpoint it seems likely
that the presence of encrusting organisms may be of positive advantage
to the crab. At all events, Spirorbis is quite commonly found attached
especially to the chele of P. platycheles—a position likely to ensure
commensalism (Plate 2, D).
II. MopIFICATIONS WHICH TEND TO PREVENT CHOKING BY MUD.
A Macrurous form such as we suppose the Galatheid ancestor to have
been, swimming in the clearer open water, required, and probably pos-
sessed, no special devices for protection of the branchial cavity from
stoppage : we find in the Lobster, Peneus, etc., a notable absence of
such protective devices. Here, the gills are just sufficiently well guarded
88 K. ZIMMERMANN,
against dangers of friction, etc., by the lateral branchiostegite flap of the
carapace, which loosely overhangs the cavity. The case of the Brachyura
is quite otherwise. These shore-living Crustacea are constantly exposed
to the dangers of life in the wave-washed zone, and protection against
one of the greatest of these dangers is ensured by the enclosing of the
branchial cavity by the strongly-curved branchiostegite. This leaves
only the following apertures : a pair at the posterior end of the carapace,
a pair at the bases of the chelze, a pair near the mouth—and, on each side,
a long chink, so narrow as to be practically inconsiderable, between
carapace and thoracic leg-bases. The first two pairs of apertures (en-
trance channels for the breathing current) are well guarded by a straining
apparatus formed by a fringe of hairs of very complex structure (Plate
4, G), while the aperture on each side of the mouth (an exit channel)
can be protected by the folding of the plate-like maxillipedes against the
body-wall. The fourth pair of apertures, mere chinks, are curtained by _
a fringe of hairs bordering the branchiostegite and by the tufts of “‘ coxo-
poditic sete.”
One might expect to find in Galatheide a type of arrangement more
or less intermediate between these two extremes—the Macrurous and
the Brachyurous—and such is, in fact, revealed. Throughout the group,
the closing-in of the branchial cavity is far less complete than in the
Brachyura, although a curved and down-bent branchiostegite protects it
laterally, and the paired inhalent aperture (posterior, near the bases of
appendages XII and XIII) is guarded by-a ring of hairs. Coxopoditic
tufts also prevent the entrance of mud through the longitudinal crack
between branchiostegite and leg-bases—which crack is far wider than in
Brachyura, the whole branchial cavity being wide in the vertical rather
than in the horizontal plane.
Galathea, an active swimmer, has retained some of the epipodites so
characteristic of primitive Macrurous forms like Penzeus. In G. squami-
fera (common around our coasts), there are epipodites, fringed with
long and fairly simple hairs, on appendages VIII to XI (Plate 2, B, and
Plate 1, F). One important function of the epipodites, as established by
M. Bohn (“‘ Des mécanismes respiratoires chez les Crustacés Décapodes,”
Bull. Sot. Fr. et Belg., XXXVI) is to brush the surfaces of the Arthro-
branch gills and sweep them clear of particles. With so efficient a sweep-
ing mechanism, it seems that elaborate precautions against the entrance
of mud are unnecessary : we find that in this species the guardian-hairs
which fringe the inhalent aperture are of the same fairly simple type as
those which occur along the whole of the carapace edge (Plate 7, B).
HABIT AND HABITAT IN THE GALATHEIDEA. 89
This absence of high specialization along this particular line should be
correlated with the habitat of the species, which visits the muddiest part
of the shore (just below low-tide mark) only for a very short time in
spring. The allied species, Galathea strigosa, shows increased com-
plexity of structure of the hairs which guard the inhalent aperture and
fringe the branchiostegite. We connect the advance in specialization
with the fact, noted by M. Bohn (op. cit.), that “in G. strigosa, consider-
able movements of the carapace supplement the action of the scaphog-
nathite.”’ This carapace-flapping would doubtless expose any epipodites
present on appendages IX to XI to the danger of being bruised and
torn—at all events, the epipodites of these segments are wanting. This
reduction of sweeping mechanism within doubles the need for a guard at
the entrance portals, which need is satisfied by the increased complexity
of straining-hairs described above. Thus, in G. strigosa, feebleness of the
scaphognathite has induced flapping of the carapace—this being in its
turn connected with reduction in the number of epipodites and correlated
complexity of straining hairs (see Plate 2, B, and Plate 4, F). It is in-
teresting to note that in this species the epipodite of appendage VIII
has alone survived, and this perhaps owing to its position opposite the
blunt angle of the branchiostegite, where in all probability friction is not
eTeat.
Galathea intermedia, like G. strigosa, has suffered reduction in the
number of its epipodites (though we are as yet unable to guess at the
biological significance of this reduction) ; here, only epipodites VIII and
IX remain, and here again correlated specialization of the straining-
hairs is observed (Plate 4, E).
Two deep-water species of Galatheidea—G. nexa (to 70 fathoms)
and Munida subrugosa (to 600 fathoms)—while resembling G. squamifera
in their possession of the full number of epipodites (series VIII to XI),
yet afford a parallel with the case of @. strigosa and G. intermedia in the
relatively complex structure of the straiming-hairs. This apparent
anomaly seems to point to a need for special precaution against choking
of the branchial passage in these two deep-water species; this is one
item of a lengthy list of peculiarities which characterize the branchial
apparatus of deep-sea members of widely dissociated groups (compare
the peculiarities of the branchial organs of the Lepetidze among Proso-
branch Gasteropods, etc. etc.).
A striking feature of such shore-living types as Porcellana is the
complete loss of the epipodites of appendages VIII to XI. This reduc-
tion should perhaps be correlated with the marked development of the
90 K. ZIMMERMANN.
clinging habit and the radial working of the legs, which entail move-
ments likely to endanger organs occupying the position of epipodites.
We should probably connect with this habit of spreading the legs radially
(a habit which prevails throughout the Galatheidea, though it is most
marked in Porcellana) the peculiarities of the general gill-formula of the
eroup, which is characterized by the absence of podobranchs and im-
portance of the pleurobranchs. Some of the leg movements involved
would seem to be a source of danger to gills in the position of podo-
branchs (near the outer edge of the branchial chamber), exposing them
to a risk of friction against one another and against the edge of the
branchiostegite. Reduction of the organs exposed to this danger is
accompanied by increased importance of the gills of the two inner series
(arthrobranchs and pleurobranchs). (See Plate 1, F and G.)
In connection with the ascent of the shore by Porcellanide, the altera-
tion in shape of the branchial cavity is noticeable, the shape of the cavity —
being practically of a type intermediate between those found in the
swimming Galathea and the established (unrelated) shore-form, Cancer.
Porcellana platycheles, a sluggish species inhabiting the muddiest
part of the mud-zone, shows a marked degree of specialization of the hairs
which guard the inhalent aperture. These hairs, as well as those of the
coxopoditic tufts, are of a much-branched and twice-pinnate type, and
exactly resemble those which, in members of the Brachyura, constitute
so effective a strainer, being totally dissimilar to the corresponding
structures in Galathea (any species). (Plate 4, G.)
It is remarkable that P. longicornis, unlike platycheles, has none of this
complicated structure: all the hairs near openings of the branchial
cavity are alike of the simple type characteristic of Galathea squamifera
(Plate 4, B).
It is necessary to bear in mind the difference in habitat of the two
species, P. platycheles being a typical mud-dweller, whilst longicornis
frequents such shores as those of Guernsey, where igneous rocks weather
into reefs separated by steep gullies, swept perfectly clear of mud by the
tidal currents.
With specializations which tend to promote efficiency of the breathing
current we must class a peculiar growth of hairs found on the basal joint
of the third maxillipede of all species so far examined. These hairs are
short and strong, furnished with short, jagged saw-teeth, and are matted
together to form a kind of felt-work across the gap between the maxilli-
pedes of the two sides. This acts as a forward extension of the floor of
the branchial cavity, and seems to guard against the entrance of water
HABIT AND HABITAT IN THE GALATHEIDEA. 91
from below, which might meet and check the outgoing current (see Plate
4 and Text Figure 1).
Various members of the group show an interesting series of devices
ensuring steadiness of the breathing current—such devices being par-
ticularly necessary in animals with the enclosed type of branchial cavity.
Prof. Pearson, in his Cancer Memoir (L.M.B.C.), has pointed out the
existence in that part of the carapace which floors the branchial cavity
of a ridge, which by its presence helps to maintain a steady current of
water past the gills. Specializations of an apparently somewhat similar
function are visible in certain of the Galatheidea. The branchial cavity
of Galathea and of Munida is long and narrow, with a slight spiral twist,
CLzL_ \ &
—— 2
CLI : ——
&—
Fic. 1.—Diagram-Longitudinal section through the front end of the body of one of
the Galatheidea.
yv.b. =ventral body-wall.
ap. =branchiostegite of one side.
br.ca. = branchial cavity of that side.
ex. =direction of ex-current stream.
Dp: =line of a theoretical in-current.
m. =position of matted hairs on the maxillipede bases, which prevent the
entrance of the current p.
and is floored (unlike those of Brachyura) by the body-wall itself: we
trace in this floor the line of a definite, though not prominent, longitudinal
ridge external to a groove along which the main body of the breathing
current appears to flow (Plate 3, A, 1 and 11).
Porcellana has a corresponding specialization more nearly of the
Cancer type: the branchial cavity is partially floored (i.e. towards its
front end) by a special portion of the edge of the branchiostegite, which
is peculiarly twisted to produce a ridge doubtless similar in function to
the rather more definite ridge of Cancer (Plate 3, B, and Plate 1, G).
Porcellana shows a remarkable respiratory habit—that of temporary
suspension of the breathing activities on alternate sides of the body.
92 K. ZIMMERMANN.
The flagellum of one of the maxillipedes (probably of the 2nd) is ob-
viously of use in strengthening and accelerating the ex-current stream,
and its motion or stilmess forms a good guide to the progress of the
breathing activities on either side of the body, in addition to the indica-
tion furnished by the motion of particles in the water. It was noticed
that both P. longicornis and P. platycheles, when at rest, almost in-
variably hold the chela of one side (a) further away from the body than
its fellow (8): subsequent observation, many times confirmed, revealed
the fact that only from the exhalent aperture of the a side did an ex-
current stream proceed: apparently no respiratory stream was passing
through the branchial cavity of the § side, and certainly the flagellum
of that side was at rest. Supposing that the chela of the left side is held
away from the body: only the left flagellum is meanwhile at work, a
strong ex-current stream proceeds from the /efé side only, and the anten- —
nules, at their water-testing work, are constantly directed towards the
right side of the animal (Plate 2, C and D). Meanwhile, on the right side
of the body issues no ex-current stream, but generally the right antenna
is kept in fairly constant motion, being swept from front to back, and
vice versa. In other words, there is apparent suspension of the respira-
tory function of the right side of the body, compensated by the re-
doubled activity of the sensory function of the same side. In a normal
captive Porcellana, the duration of this period of suspension is usually
about half an hour ; at the end of that time the animal becomes restless,
“* fidgets,’’ and ends by reversing the functions of the two sides of the
body, after a brief period of irregular movement of first one flagellum,
then the other, and occasionally even of both at once. It must be noticed
that in Porcellana there is no reversal of the current such as M. Bohn
observes (C.R. Ac. Sct., CX XV, 1897, p. 441, “Sur le renversement du
courant respiratoire chez les Décapodes”’) in Carcinus, ete., and which
may serve to rest the muscles of the scaphognathite or to cleanse the
branchial cavity. Probably this resting of the muscles is at least as well
ensured by the alternate working of the organs of the two sides. M..
Bohn remarks that, in animals which have the reversal habit, the number
of reversals within a given time may be increased by placing the animal
in a toxic solution such as extract of Red Seaweed. Similar experiments
performed on Porcellana produced no reversal of the current, but had
the effect of causing the alternations in function of the two sides to become
rapid andirregular. Galathea exhibits no such alternation, and on placing
it in Red Seaweed extract there was detected distinct reversal of the
respiratory stream, although the backward current produced was but
HABIT AND HABITAT IN THE GALATHEIDEA. 93
feeble and irregular. The result of the experiments performed on Porcel-
lana is surely to show that any recuperative purpose effected by the
reversal of the respiratory stream in the Decapods for which such reversal
has been proved is fulfilled in Porcellana by the alternate resting and
working of the two sides.
Throughout the Galatheid group we note a praiseworthy striving after
cleanliness on the part of its members, which must of course be referred
to the habitat of these animals. Apart from the absolute necessity for
keeping a clear channel through the branchial cavity, it is of distinct
advantage to prevent mud particles from collecting among the hairs of
the coxopoditic tufts and near the openings of the branchial cavity itself,
and it is clearly the function of the curiously modified thirteenth (last
thoracic) appendage to clean and brush these hairs, as well as the back
of the carapace. Galathea and Munida especially have need of precaution
against the settling of foreign particles in the transverse grooves of the
carapace. The ultimate segment of the thirteenth appendage in Galathea,
Munida, and Porcellana, bears hairs which by their structure are peculiarly
well fitted for this work of cleaning out chinks and crannies (Plate 4, K),
each hair being bent into a kind of sickle-shaped hook, fringed on its
inner side with short, pointed teeth, and doubtless constituting a most
effective scraper. In one species of Porcellana (P. platycheles, see Plate
7, K, 11), these hairs appear to have suffered degeneration from some un-
explained cause (perhaps in connection with the absence of carapace
ridges), growing less strongly curved and with blunt teeth. It is notice-
able that members of the genus Porcellana (without epipodites) fre-
quently thrust this appendage XIII inside the branchial cavity itself,
doubtless to clean it—a course of proceeding which Galathea (furnished
with epipodites) apparently does not follow.
The antennules (water-testing organs) and the antenne (which are
still important tactile organs in the Galatheidz) must, if they are to
retain their sensory function, be kept scrupulously clean, and their
cleansing, which frequently takes place, is a process to delight the ob-
server. These appendages are bent sharply downward, then the endopo-
dites of the third maxillipedes are unfolded, and antennules and antenne
are drawn slowly upwards in such a manner as to be thoroughly well
combed by the long hairs of these palps, which hairs have the form of
strong double-edged saws or combs (Plate 4, 1,1). These endopodites of
the third maxillipedes, by the way, exhibit an interesting series of special-
izations throughout the group. Their main functions are (a) to gather
94 K. ZIMMERMANN.
in small particles of food to the mouth by a sweeping movement ; (0)
to comb the hairs of antenne and antennules ; and (c) to guard, when
folded, the exit channels of the branchial cavity. In Galathea and
Munida, the joints of the endopodite are long and thin, and the whole
maxillipede approaches in form the type of the primitive Arthropod
appendage, save that the endopodite is slightly flattened, and can, when
folded, form a fairly plate-like structure. P. platycheles shows greater
specialization of the endopodite, the joints being very much flattened
and broadened, although the span of the limb when straightened is con-
siderable. P. longicornis is in this respect almost intermediate between
the two types (Plate 6, A, B). All these species have specialized hairs of
two kinds on the ultimate and penultimate segments of the endopodite.
These are—(a) sweeping hairs (Plate 4, C), very long and slender, bearing
two regular rows of fine branches ; and (6) combing hairs (Plate 4, I, 1),
not so long as the former, but stouter, and bearing two rows of very stiff
points like the teeth of a double comb.
Comparison with the third maxillipede of Cancer and allied Brachyura
is instructive. In Cancer, the broadening and flattening of the proximal
portion of the endopodite and the reduction of its distal joints have pro-
ceeded far (see Plate 3, D, EH, F). The function of the endopodite here is
perhaps exclusively to protect the exit channel, and it is converted into
an organ primarily plate-like and protective, and destitute of sweeping
hairs. In connection with the life high up the shore, antenne and anten-
nules are reduced in size and importance (experiments prove the former
to be practically insensitive to touch), so that this double reduction
renders the combing of antenne and antennules by the hairs of VIII im-
practicable. The combing hairs, having lost their function, are obviously
degenerate : though they retain their two rows of lateral branches, these
branches are so much thickened as to be almost fused in rows, and quite
disqualified as combing teeth. The fact that Algal growth has been found
attached to the antenne of practically every specimen of Cancer pagurus
examined appears to prove conclusively the absence of combing device
and sensitivity. Carcinus (a more active Brachyuran than Cancer, and
one proved by experiment to have greater power of antennal perception),
has the third maxillipede just long enough to clean the antenna tip, and
it is noticed that in members of this genus the combing hairs have persisted
without degeneration—also Algal growth is less commonly present on the ©
antenna, and never present near the tip. On the other hand, P. platy-
cheles presents, in this matter of the combing hairs, a condition markedly
analogous with that of Cancer. This must be connected with the general
HABIT AND HABITAT IN THE GALATHEIDEA.
erab-like habit and sluggish nature of the species (compare the settlement
of Spirorbis, etc., on the carapace and chele).
In this last instance, then, P. platycheles exhibits a type of specializa-
tion markedly analogous with that of the true crabs, and the species once
more asserts its right to be placed among the upper branches of our tree
of Galatheid ascent.
EXPLANATION OF PLATES.
Plate 1.
A.-E: Thoracic nervous systems of Decapod Crustaceans.
A. Of Astacus fluviatilis (after Huxley).
B. Of Galathea squamifera |
C. Of Munida rugosa ; members of the Galatheidea.
D. Of Porcellana platycheles }
E. Of Cancer pagurus.
Gre i: =supra-cesophageal mass.
C. @. =circum-cesophageal ring.
S. @. =sub-cesophageal ganglion.
Sait =gap for sternal artery.
Gn. 4, 5-8. =last 5 thoracic ganglia.
Gn. 8. =ganglion of segment XIII.
Vn. =ventral nerve-mass.
FandG. Branchial cavity of right side, showing bases of thoracic legs.
A. Of G. squamifera.
B. Of P. platycheles.
Pl. X to XII[=Pleurobranchia.
Ep. VIII to XI=Epipodites.
Plate 2.
A. Side view of carapace of Galathea strigosa.
Ep. Vill=epipodite of the 3rd maxillipede (usually turned into the
branchial cavity).
B. An epipodite of G. squamifera, showing sweeping hairs.
Ms.=muscle.
D. P. platycheles, dorsal view. The flagellum of the left side is at work.
(N.B.—In this specimen, the chela of the right side is the larger.
The illustration by no means does justice to the general shagginess
of the species.)
96 K. ZIMMERMANN.
C. Enlarged view (diagrammatic) of a portion of the above.
a. =antennules.
m. =plate-like endopodite of VIII.
fl. =flagellum at work.
ex. =ex-current stream.
S. =Spirorbis tube on chela.
Plate 3.
A. Side view of branchial cavity of G. squamifera, gills removed (diagram-
matic).
C: =cut edge of body-wall, etc.
In. =inhalent aperture.
Ex. =exhalent aperture.
Gr. =position of groove.
1 =line of a not prominent ridge.
Au, Biand ui, and C i=diagrams of various branchial cavities in T.S.
Au. Of G. squamifera.
B. Of P. platycheles (i, near front end; u, further back).
Ci. Of C. pagurus.
Bin. =Branchiostegite of P. platycheles, inner surface.
Cu. =Branchial cavity of Cancer exposed.
ie =ridge.
br. =branchiostegite.
C. =cut edge of carapace.
D.=3rd maxillipede of G. squamifera (right side).
ois ie ,, P. platycheles -
io - » C. pagurus .
en. = endopodite.
ex.=exopodite.
G. =Antenna of C. pagurus, with Algal growth.
Plate 4.
Drawings of single hairs (much enlarged).
A. Simple hair, e.g. “ shaggy hairs” of P. platycheles.
B. Once-pinnate hair, on carapace ridges of Galathea, also fringing the
branchiostegite in G. squamifera.
C. In-sweeping hair, on last two joints of endopodite of 3rd maxillipede
in Galatheidea.
D. Kpipodite hair.
E. Filter hair, frmging branchiostegite, etc., in G. intermedia, G. nexa,
and Munda subrugosa.
i
HABIT AND HABITAT IN GALATHEIDEA, Oe
Strigosa hair, fringing branchiostegite, etc., in G. strigosa.
Tree-like filter hairs, fringing branchial apertures of P. platycheles
and Cancer, etc.
1. Cluster, with collected mud.
ii. Tip of one hair, more highly magnified.
Matted hairs, inner side of basal joint of 3rd maxillipede in Gala-
theidea.
Combing hair, last two joints of VIII in Galathea, Munida, P. longi-
cornis, and Carcinus menas.
Degenerate combing hair, P. platycheles and C. pagurus.
Sickle hair, ultimate joint of XIII in Galatheidea (except P. platy-
cheles).
Degenerate sickle hair (P. platycheles).
NEW SERIES.—VOL. X. NO. 1. NOVEMBER, 1913, G
PLATE E
Harir AND HABITAT IN GALATHEIDEA.
K. ZIMMERMANN.
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HABIT AND HABITAT IN GALATHEIDEA,
PLATE IV
K. ZIMMERMANN.
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Baltes
The Shore Fauna of Cardigan Bay.
By
Chas. L. Walton,
University College of Wales, Aberystwyth.
CaRDIGAN Bay occupies a considerable portion of the west coast of
Wales. It is bounded on the north by the southern shores of Carnarvon-
shire ; its central portion comprises the entire coast-lmes of Merioneth
and Cardigan, and its southern limit is the north coast of Pembrokeshire.
The total length of coast-lie between Braich-y-pwll in Carnarvon, and
Strumble Head in Pembrokeshire, is about 140 miles, and in addition
there are considerable estuarine areas. The entire Bay is shallow ; for the
most part four to ten fathoms inshore, and ten to sixteen about the centre.
It is considered probable that the Bay was temporarily transformed
into low-lying land by accumulations of boulder clay durmg the Ice Age.
Wave action has subsequently completed the erosive removal of that
land area, with the exception of a few patches on the present coast-line
and certain causeways or sarns. Portions of the sea-floor probably still
retain some remains of this drift, and owing to the shallowness, tidal cur-
rents and wave disturbance speedily cause the waters of the Bay to become
opaque. The prevailig winds are, as usual, south-westerly, and heavy
surf is frequent about the central shore-lme. This surf action is accen-
tuated by the large amount of shingle derived from the boulder clay.
The action of the prevailing winds and set of drifts in the Bay results in the
constant movement northwards along the shores of a very considerable
quantity of this residual drift material. Where checked by shore contour
or river current this drift accumulates to form storm-beaches, which
have eventually deflected certain rivers and streams to the northward,
as in the case of the Ystwyth at Aberystwyth, the Clarach stream a
little further to the north, and the Leri at Borth. Other large accumula-
tions have assisted in the raising of the sarns or “ causeways,” extensive
shallow regions, several of which run out in its northern half into the
Bay for a considerable distance. One of these, the Sarn Badrig, dries at
low-water spring-tides, nearly 14 miles from land.
THE SHORE FAUNA OF CARDIGAN BAY. 103
Large amounts of muddy fresh water are poured into Cardigan Bay
by the numerous torrential rivers and streams which flow from the
mountain regions where the rainfall is heavy. Some of these (from N. to
S.) are the Soch, Rhyd-hir, Erch, Wen, Glaslyn, Dwyryd, Artro, Mawd-
dach, Dysynni, Dyfi (with subsidiary streams Einon, Clettwr and Ler),
Rheidol, Ystwyth, Wyre, Aeron, Teifi, and Nevern. Of these, the Glaslyn
and Dwyryd, the Mawddach, the Dyfi and subsidiaries, and the Teifi,
form estuaries of considerable extent. After heavy rain, the inshore
waters of the Bay are discoloured for some distance from the river-
mouths. This discolouration is chiefly to the northward of the river
mouths, owing to the surface waters bemg driven in that direction
by the prevailmg rain winds. The junction between the surface
of the muddy fresh water (floating over sea water) and the clear
sea is frequently plamly visible. The Bay is bounded for the most
part by high land, but the continuity is broken by the deep clefts
and estuaries of numerous rivers. The coast-line comprises an alternat-
ing series of (1) steep, rocky cliffs, consisting of Cambrian Ordovician
and Silurian grits and shales, though there are some exposures
of igneous rock, (2) drift clifis of lower elevation, and (3) estuaries.
In each of these the characteristics of the tidal area are different. In
the first it is chiefly reef and hard erosion plane, with great variability in
local conditions according to the strike and dip of the rock, the amount
of exposure, and the quantity of detritus which washes to and fro in the
gullies between the rock-ridges. If the strike of the rocks is fairly
parallel with the coast, the dip of the rocks becomes an important factor
as regards the Fauna. If it is low, the whole surface is exposed to wave
action and the rocks are barren; if it is high with a landward dip, they
are also barren; but if high and seaward, there may be a fairly good
Fauna on the more sheltered landward slope. Outlying reefs may provide
shelter, even if submerged, because they break the force of a ground
swell and lessen the amount of wave-borne detritus. The shingle derived
from boulder elay and carried along the coast is often largely augmented
by detritus from the srit cliffs of the locality.
(2) Where drift cliffs prevail, much of the foreshore consists of shingle
with large stretches, or low reefs of boulders, and local patches of coarse
sand.
(3) In the estuaries, and often for some distance on either side, the
tidal area is sandy or muddy and the foreshore is dune-capped. More
recently there appears to have been a considerable influx of finer sand
(presumably from deeper water) along the greater part of the shore-line,
104 CHAS. L. WALTON.
resulting in appreciable local modifications of some of the elements of
the Fauna.
The portion of the Bay in which the above-mentioned conditions are
most typically developed lies between Portmadoc to the north and
Cardigan to the south. Aberystwyth lies practically in the centre, and
as the faunistic work has been carried out from that pot, and since time,
distance, and accessibility have, as usual, played their parts, the coast
in the vicinity of Aberystwyth has been much more thoroughly examined
than the rest. Practically no records have been made south of the Teifi,
and but few above Portmadoc. It is fortunate that the region most
readily accessible includes all the types of coast. It will be seen that
there are three principal types of shore, and that these are subject in a
marked degree to several important factors. (1) Wave disturbance
(surf action). (2) Erosion by detritus and shingle. (3) Muddy fresh
water.
These adverse conditions are reflected in the comparative poverty of the
Fauna. In connection with the above factors, peculiarities have been
observed in the distribution of certain groups, notably some of the
Mollusca, and these are dealt with separately. It is hoped, later, to
study the Fauna of the Bay below low-water mark and a number of
records are already available : the comparison should prove of interest.
It follows from what has been said above, that the shore Fauna will
consist chiefly of the more hardy species, supplemented by some others
that may survive in the more sheltered spots. The nomenclature adopted
is mainly that of the “‘ Plymouth Marine Invertebrate Fauna,” 1904.
It will be observed that the Echinoderms and Ascidians are very
poorly represented. The Crustacea and fishes have been limited as far
as possible to shore forms, but a hard-and-fast line cannot be drawn. The
worms have not been at all adequately examined and require the attention
of a specialist. The following abbreviations are used to denote the
observers responsible for the various records :—
HS JE. = Prot tJ. Bleue. DSc:
Boe Wis F.8. Wright.
CMe Wey 2 Oe Wealtions
THE SHORE FAUNA OF CARDIGAN BAY.
105
LIST OF LITTORAL ALG.
A—Aberystwyth ;
CHLOROPHYCEAE.
Enteromorpha compressa, Grev.;
A, C,8.
Enieromorpha linza, J. Ag.; ©.
Enteromorpha intestinalis, J. Ag.;
A, ©, 58.
Ulva latissima, J. Ag.; A, ©, 5.
Chaetomorpha melagonium, Kitz.;
Bee:
Chaetomorpha tortuosa, Kiitz.; A.
Cladophora pellucida, Kiitz.; Ie
Cladophora albida, Kiitz.; A, C.
Cladophora sericea, Reinb.
Bryopsis plumosa, C. Ag.; HOS
PHAEOPHYCEAE.
Desmarestia aculeata, Lamx.; A, C.
Dictyosiphon feeniculaceus, Grev.; A.
Punctaria latifolia, Grev.; A, ©,
Myriotrichia claveformis, Harv.
var. filiformis, Farl.; A.
Asperococcus echinatus, Grev.; A.
Streblonema faciculatum, Thur.; ie
Ectocarpus confervoides, lie Jol: Ay.
var. siliculosa, Kjell.
E. tomentosus, Lyngb.; A, 5.
Elachista fucicola, Fries.; A.
Sphacelaria cirrhosa, C. Ag.; A.
Sphacelaria plumigera, Holm.; A.
Cladostephus spongiosus, C. Ag.;
ACS.
Cladostephus verticillatus, C. Ag.; ALC.
Stypocaulon scoparium, Kiitz.; C, 5.
Ralfsia verrucosa, Aresch.; A.
Stilophora rhizodes, J. Ag.; 8.
Chordaria flagelliformis, C. Ag.; A. 8.
Mesoglaa vermiculata, Le Jolie S:
Castagnea virescens, Thur.; A, S.
Castagnea griffithsiana, J. Ag.; A.
Leathesia difformis, Avesch.; A, ©, S.
Phyllitis fascia, Kiitz.; A.
Chorda filum, Stackh.; A.
C—Clarach and north ; S—Allt Wen and south.
Laminaria saccharina, Lamx.; A, C, 8.
Laminaria digitata, Kdm.; AS CUS:
Fucus cerenoides, Linn.; A.
Fucus vesiculosus, Linn.; A, C, 8.
Fucus serratus, Linn.; A, C, 8.
Ascophyllum nodosum, Le Jol.;A,C,S.
Pelvetia canaliculata, Dene eb, Thur.
Halidrys siliquosa, Lyngb.; A, C, 8.
Dictyota dichotoma, Lamx.; 8.
RHODOPHYCEAE.
Bangia fuscopurpurea, Lyngb.; C.
Porphyra linearis, Grev.; A.
Chantransia virgatula, Thur.
Chondrus crispus, Stackh.; A, S.
Gigartina teedii, Lamx.; A.
Phyllophora membranifolia, J. Ag.; A.
Ahnfeldtia plicata, Fries.; A.
Catanella spuntia.
Rhodymenia palmata, Grev.; A.
Lomentaria articulata, Lyngb.; A.
Laurencia hybrida, Lenorm.; S.
Polysiphonia urceolata, Grev.; A.
var. patens, J. Ag.
Polysiphonia elongata, Grev.; 8.
Polysiphonia violacea, Wyatt ; AC
Polysiphonia nigrescens, Grev.; A.
Callithamnion hookert, C. Ag.
Piumaria elegans, Bonnem.; 5.
Ceramium strictum, Harv.
var. divaricata, Holm. & Batt. A.
C. diaphanum, Roth.; A.
' rubrum, C. Ag.; A.
var. proliferum, J. Ag.
C. acanthonotum, Carm.; A.
C. ciliatum, Duclaz; A.
Furcellaria fastigiata, Lamx.; 8.
Polyides rotundus, Grev.; A.
Hildenbrandtia prototypus, Nard.
var. rosea, Kiitz.; A, C, 8.
Lithothamnion polymorphum, Aresch.;
A, 5.
Corallina officinalis, Linn.; A, C, 8.
(>)
106 CHAS. L. WALTON.
The region between Ystwyth and Dyfi appears to be hostile to certain
Alge, notably Stilophora rhizoides, Mesoglea vermiculata, Dictyota dicho-
toma and Laurencia hybrida, which are absent from it, and Chondrus
crispus and Castagnea virescens, which become more common outside it.
LIST OF SHORE FAUNA.
PORIFERA.
Sycon compressum, Flemmg. Low-water mark, in sheltered spots, upon
Alge, ete. (H. J. F.; C. i. W.)
S. coronatum, Ellis and Sol. Same as last. (C. L. W.)
Halisarca dujardini, Johnston. Under surface of stones. (C. L. W.)
Halichondria panicea, Pallas. Common in sheltered spots almost
everywhere. (C. L. W.)
Hymeniacidon sanguineum, Grant. Aberystwyth. (C. L. W.)
CQELENTERATA.
Podocoryne carnea, M. Sars. Aberystwyth. (C. L. W.)
Coryne vaginata, Hincks. On Alege in rock-pools or reefs south of
Borth. (C. L. W.)
Zanclea implexa, Alder. One colony, collected by Dr. Salter, 1907.
(Cz TW?)
Obelia dichotoma. On piles of Railway Wharf, Aberdovey, and rock-
pools Gwhert-on-Sea. (C. L. W.)
O. geniculata, Linneus. Generally distributed. (H.J.F.; C. L. W.)
Sertularia pumila, Linneus. Generally distributed ; often abundant on
Fucus. (C. L. W.)
Plumularia echinulata, Lamarck. Aberystwyth. (C. L. W.)
P. pinnata, Linneus. General in sheltered pools. (C. L. W.)
P. similis, Hincks. (H. J. F.)
Actinia equina, Linneus. Generally distributed and locally common.
Aberystwyth, Y-Gamlas, Mochras, etc. (C.L.W.) See Journal
Marine Biological Association, October, 1911. pp. 228-230.
Anemonia sulecata, Penn. Generally only a few. Aberystwyth and for
a few miles to the south. Tonfunau, ete. (C. L. W.)
Sagartia miniata, Gosse. One specimen. Aberystwyth. (C. L. W.)
S. undata, O. F. Miiller. Observed at Clarach, a little bay to the north
of Aberystwyth. Small specimens occur under stones which have
become fixed in grooves, on an otherwise very barren erosion plane.
Individuals, when kept in captivity, very averse to light. One
large specimen on reef below the College. (C. L. W.)
THE SHORE FAUNA OF CARDIGAN BAY. 107
S. ornata, Holdsworth. This rare Actinian has occurred in pools at
extreme low water, on reefs below the University. (C. L. W.)
See Journal Marine Biological Association, October, 1911. pp.
236-237.
Tealia coriacea, Cuvier. Not common, but occurs in favourable situations
as in pools at Clarach, which are sheltered by large shelving rocks ;
there specimens of large size may be seen. One individual
observed among Mussels at Mochras. (C. L. W.)
ECHINODERMATA.
Henricia sanguinolenta, O. F. Miller. One specimen. Aberystwyth ;
extreme low water, February, 1913. (C. L. W.)
Asterias rubens, Linnzeus. Has been common 1898 and 1904—5, but
now scarce, Aberystwyth. (H.J.F.) Sometimes occurs on the
seaward Mussel beds, Aberdovey. (C. L. W.)
Amphiura sp. Not uncommon under stones. (C. L. W.)
Ophiothrix fragilis, O. F. Miller. A number were observed under stones
among Laminaria during the abnormally low tides of February,
1913. (C. L. W.)
TURBELLARIA.
Fovia affinis, Stimpson. Under stones, near Harbour, Aberystwyth.
(C. L. W.)
Leptoplana tremellaris, O. F. Miller. Common. (C. L. W.)
NEMERTINI. |
Amphiporus lactifloreus, Johnston. Aberystwyth. (C. L. W.)
Lineus longissimus, Gunn. Aberystwyth. (H. J. F.)
Tetrastemma sp. Aberystwyth. (C. L. W.)
Dinophilus teniatus, Harmer. Aberystwyth. (H. J. F.)
POLYCH ATA.
Lagisca floccosa, Savigeny. Aberystwyth. (C. L. W.)
Harmothoe imbricata, Linneus. Gwhert-on-Sea, two specimens.
(C. L. W.) Central dorsal area dark, margins pale.
Eulalia viridis, Miller. Frequent on reefs and with Sabellaria. (C. L. W.)
Psamathe fusca, Johnston. Aberystwyth. (C. L. W.)
Castalia punctata, Miiller. Clarach, with ova, June 9th, 1910. (C. L. W.)
Nereis pelagica, Linneeus. Aberystwyth. (C. L. W.)
Lysidice sp. Aberystwyth. (C. L. W.)
Terebella sp. Fairly common. Aberystwyth. (C. L. W.)
108 CHAS. L. WALTON.
Lanice conchilega, Pallas. Local. (C. L. W.)
Arenicola marina, Linneus. Abundant on Cockle beds in estuaries.
(C. L. W.)
Cirratulus cirratus, O. F. Miller. Aberystwyth. (H. J. F.)
Pomatoceros triqueter, Lmneeus. Not uncommon under stones. (C. L. W.)
Spirorbis borealis, Daudin. General on Fucus, etc. (C. L. W.)
Sabellaria alveolata, Linneus. Locally very abundant near sandy
areas, and has then a considerable influence in binding together
boulders and loose stones. It is almost invariably accompanied
by Eulalia viridis and Ulva, but precludes many other species by
fille up the crevices and bases of rocks and stones which otherwise
afford them shelter. (C. L. W.)
GEPHYREA.
Sipunculus nudus, Linneus. One specimen, Aberystwyth. (H. J. F.)
POLYZOA.
Scrupocellaria reptans, Linneus. Aberystwyth. (C. L. W.)
Membranipora pilosa, Limneeus. Aberystwyth, ete. (C. L. W.)
M. membranacea, Linneus. Aberystwyth. (C. L. W.)
Crisia cornuta, Linnzus. Under stones, Aberystwyth. (C. L. W.)
C. denticulata, Lamarck. Aberystwyth. (C. L. W.)
Alcyonidium hirsutum, Flemmeg. Upon Algw, Aberystwyth, Borth, ete.
(Cal W=)
Amathia lendigera, Lmnzus. Upon old Mussels, Aberdovey. (C. L. W.)
Bowerbankia imbricata, Adams. With above. (C. L. W.)
Pedicellina cernua, Pallas. With A. hirsutum, Clarach. (C. L. W.)
MOLLUSCA.
Acanthochites fascicularis, Lmnzus. Aberystwyth, ete. (C. L. W.)
Trachydermon cinereus, Linneus. Aberystwyth. (H.J.F.) Morva,
Clarach. (C. L. W.)
Patella vulgata, Linneus. Abundant; mainly on the sheltered land-
ward side of shelving rocks, and then often of very large size.
(CxLe Wey
Helcion pellucida, Linneus. Aberystwyth, above extreme low tides
rather rare. (H.J.F.) Fairly common on Laminaria when tides
are unusually low. (C. L. W.) Coves, Gwhert-on-Sea, fairly common.
(C.L. W.) One specimen was discovered near Aberystwyth at
high-water mark attached to a stone, evidently due to Laminaria
cast up after storms.
THE SHORE FAUNA OF CARDIGAN BAY. 109
Fissurella greeca, Linneus. One specimen, Aberystwyth. (H. J. F.)
Acmeea virginea, Miller. lLlanina, near New Quay, one specimen.
(C. L. W.) Shells are fairly frequent. (H. J. F.)
Gibbula magus, Linneus. Y-Gamlas, near Pwllheli. (C. L. W.)
G. cmeraria, Linneus. Rare. Two living specimens south of Llanrhystyd
and two at Gwhert-on-Sea. (C. L. W.)
G. umbilicata, Montagu. Very abundant in certain areas. (H.J.F.;
C.L.W.) New Quay, Llanrhystyd, north of Towyn, Mochras, near
Pwllheli, etc. Considerable differences in form and colouration are
observable. The general shell form varies from a dorso-ventrally flat-
tened or “ Tam-o’-Shanter,’ to a clumsy rounded turban shape.
In the latter the summit is generally eroded and the penultimate
whorl often imbricate and inflated. These differences appear to be
due to age. The umbilicus varies between large, open, and deep, and
narrow, slit-like, and shallow. These differences appear equally in
local examples and in specimens sent from Plymouth, and do not
depend entirely upon age and size; as in several instances the
umbilicus was wider and deeper as size increased. The narrowing
appears to be due to growth of the adjacent edge of the imner
lip, which takes place in some individuals, but not im others.
The colour bands may be few and obvious, or numerous and
obscure.
Monodonta crassa, Montfort. Distribution more restricted than the
last ; often very abundant and large. (C. L. W.)
Calliostoma zizyphinus, Linneus. One small specimen, Aberystwyth.
(CaL. W:)
Phasianella pullus, Linneus. One specimen, on Laminaria, extreme
low water, Aberystwyth. (C. L. W.)
Lacuna divaricata, Fabricius. On Alge@, not uncommon. (C. L. W.)
L. puteolus, Turton. Aberystwyth, one specimen living among Balanus
perforatus. (C. L. W.)
Littorma littorea, Linneus. Common almost everywhere. Strongly
ribbed when young, ribbings becoming either faint or obsolete after a
height of 20mm. has been attained. (C. L. W.)
L. neritoides, Linneus. Seldom common, but widely distributed.
(C. L. W.)
L. obtusata, Linneus. Abundant everywhere, on Fucus. (H.J.F.;
C. L. W.)
L. rudis, Maton. Abundant almost everywhere. The largest shell so
far found in the Bay is from Aberdovey. Total length, 19 mm. ;
110 CHAS. L. WALTON.
ereatest diameter, 13mm.; aperture of mouth, 11mm. long,
8mm. broad. Shell thick, apex acute.
Paludestrina stagnalis, Baster (Hydrobia ulve). Exceedingly abundant
on sands, Ynys Lis, Dyfi estuary ; and on stones and muddy sand at
Borth-y-Gest, Glaslyn estuary. (C. L. W.)
Trivia europea, Montagu. Rare, Aberystwyth. (H. J. F.)
Purpura lapillus, Linneus. Abundant. (H. J. F.; C. L. W.)
Nassa-reticulata, Linneus. Aberystwyth, not common. (H. J. F.)
Kolidia papillosa, Linneus. Aberystwyth, etc., not uncommon.
(Hid: Bee Ca Ws)
Aeolidiella augulata, Alder and Hancock. One specimen under a stone
very low water, Aberystwyth, February 22nd, 1913. (C. L. W.)
AK. glauca, Alder and Hancock. Rocks below College.
Facelina drummondi, Thompson. Aberystwyth. (H. J. F.)
F. coronata, Forbes and Goodsir. Not uncommon, Aberystwyth.
(Cx W-)
Doto coronata, Gmelin. Aberystwyth. (H. J. F.)
Archidoris tuberculata, Alder and Hancock. Gwhert, near New Quay,
Aberystwyth, Clarach, etc. (H.J.¥F.; C. L. W.)
Jorunna johnstoni, Alder and Hancock, Aberystwyth. (C. L. W.)
Polycera lessoni, D’Orbigny. Rare, Aberystwyth. (C. L. W.)
Acanthodoris pilosa, Miller. Aberystwyth, rare. (C. L. W.)
Lamellidoris bilamellata, Linnzeus. Aberystwyth, Llannia, Gwhert, etc.
(C. EW.)
Goniodoris castanea, Alder and Hancock. One specimen, Aberystwyth,
on. Botryllus violaceus coating Halidrys. (C. L. W.)
G. nodosa, Montagu. Not uncommon,. Aberystwyth, Clarach, ete.
(Cb OW.)
Ancula cristata, Alder. Aberystwyth. (C. L. W.)
Anomia ephippium, Linneus. Fairly common under stones. (H. J. F.)
Mytilus edulis, Linneus. Locally very abundant on shores and in
estuaries. Small where marine conditions prevail; large and of
considerable commercial importance in the estuaries of Portmadoc,
Barmouth, and Aberdovey. (C. L. W.)
Volsella barbata, Linneus. Two specimens among Sabellaria, Clarach,
1906. One, Aberystwyth, 1913. (C. L. W.)
Scrobicularia plana, da Costa. In mud on the Cockle beds of the various
estuaries. (C. L. W.)
Tellina tenuis, da Costa. One living specimen among Cockles, Ynys Las,
Dyfi estuary. (C. L. W.)
THE SHORE FAUNA OF CARDIGAN BAY. Ha bi
Macoma balthica, Linneus. Abundant on Cockle beds. (C. L. W.)
Donax vittatus, da Costa. Borth. (C. L. W.)
Tapes decussatus, Linneus. Aberystwyth. (H.J.F.; F.S.W.) Oc-
casionally ; Aberdovey, not uncommon; Monk’s Cave (south of
Aberystwyth). (C. L. W.)
T. virgineus, Linneus. Borth, ete. (C. L. W.)
Cardium edule, Linneus. Very abundant in the various estuaries
(Coe Ws)
Saxicava rugosa, Linneus. Aberystwyth, Clarach, etc. Often with
Sabellaria. (H.J.F.; C. L. W.)
CRUSTACEA.
[I am indebted to Mr. F. 8. Wright for this list, and the records are his
unless otherwise indicated. |
Canthocamptus palustris, Brady. Aberystwyth, Clarach, ete. (H. J. F.)
Balanus balanoides, Linneus. Aberystwyth. (H. J. I.)
B. perforatus, Bruguiére. Aberystwyth, etc. (C. L. W.)
Chthamalus stellatus, Poli. Aberystwyth, etc. (C. L. W.)
Verruca stroemia, O. F. Miller. Aberystwyth, etc. (C. L. W.)
Sacculina carcini, Thompson. Aberystwyth, etc. On Carcius. (H. J. F.;
Crt W.)
Dexamine spinosa, Montagu. Aberystwyth. Common.
Amathilla homari, Fabricius. Two specimens in stony pools, very low
water, Aberystwyth. (C. L. W.)
Gammarus pulex, de Geer. Aberystwyth, etc., common.
G. locusta, Limnzeus. Aberystwyth, etc., common.
Caprella linearis, Lmneeus. At low water, Aberystwyth.
Calliopius leeviusculus, Kroyer. Aberystwyth and Clarach.
Idotea baltica, Pallas, Aberystwyth.
I. marina, Linneus. Aberystwyth.
Spheroma serratum, Fabricius. Aberystwyth, common.
Jeera marina, Fabricius. Aberystwyth, common under stones. (C. L. W.
BLS. W.)
Gnathia edwardii, Spence Bate. A female was discovered under a fixed
stone in a deep pool. It occupied a burrow within a colony cf
Halichondria panicea, and within the burrow were found a number
of small yeliow ova, June 24th, 1910.
Ligia oceanica, Linneeus. Common.
Leander serratus, Pennant. Aberystwyth, common.
Crangon vulgaris, Linneus. Common.
gal, CHAS. L. WALTON.
Hippolyte varians, Leach. Aberystwyth. (C.L.W.; H.J. F.)
_ Athanas nitescens, Leach. Occasional, Aberystwyth.
Axius stirhynchus, Leach. One specimen, March 24th, 1909, at extreme
low water, Aberystwyth, in a handful of gravelly sand. Kept in
confinement in a glass vessel with a little sand, it kept the water
turbid by constant movement of the swimmerets. The identifica-
tion was confirmed by Canon A. M. Norman.
Homarus vulgaris, Milne-Edwards. Sometimes found at low-tide mark
on rocky shores. (C. L. W.)
Galathea squamifera, Leach. Aberystwyth. In sheltered areas not
subject to severe wave action. Generally in early summer, but
appearance very erratic; sometimes abundant, at others rare or
absent. (H.J.F.) A number occurred during the very low tide of
February 21st—22nd, 1913. (C.L.W.) One specimen, October,
1912. Gwbert. “(C. L. W-)
Porcellana platycheles, Pennant... Abundant under stones.
P. longicornis, Linneeus. Extreme low water, Aberystwyth. Appearance
very uncertain. (H. J. F.)
Dromia vulgaris, Milne-Edwards. One small specimen, Aberystwyth.
(Ely)
Kupagurus bernhardus, Linnzeus. Common.
Portunus puber, Linneeus. Not uncommon, Aberystwyth, ete.
Carcinus meenas, Pennant. Common.
Cancer pagurus, Linneus. Common.
Pilumnus hirtellus, Linneus. Rare.
Pinnotheres pisum, Linneus. Appears to be abundant with Mytilus
edulis, Aberdovey, ete. (C. L. W.)
PYCNOGONIDA.
“Pycnogonum littorale, Streem. Aberystwyth. (H. J. F.)
Nymphon gracile, Leach. Upon Plumularia pinnata. (F.S. W.)
TUNICATA.
Styelopsis grossularia, van Beneden. One specimen, Aberystwyth.
(CAL W-)
Botryllus violaceus, M.-Edwards. Common under stones, Aberystwyth,
beets (ed eee sala We)
Botrylloides sp. Aberystwyth.
THE SHORE FAUNA OF CARDIGAN BAY. 113
PISCES.
Blennius pholis, Linnzeus. Common and often very large. (F.S. W. ;
A. J. F.)
B. gattorugine, Bloch. Aberystwyth, occasionally. (F. 8. W.)
Cottus bubalis, Euphrasen. Fairly common and large, in rock-pools.
(ES: Woy Hogek,)
Centronotus gunnellus, Bloch. Fairly common. (F.8. W.)
Onos (Motella) mustelus, Linneeus. Common, often high in tidal zone,
(isd ee Sy Ww.)
O. (Motella) tricirratus, Bloch. One specimen, Aberystwyth, February
22nd, 1913. (C. L. W.)
Lepadogaster decandolii, Risso. One specimen found at Aberystwyth
during a low spring tide, March, 1909. (F.S. W.)
Liparis montagui, Donovan. Specimens have occurred occasionally in
tide-pools below the University. (i. 8. W.)
L. vulgaris, Fleming. Occasional young specimens, Aberystwyth.
eS. W’.)
Nerophis lumbriciformis, Willoughby. Scarce ; two specimens in half-
tide pools, Aberystwyth. (F.S. W.)
Gasterosteus spinachia, Linneeus. Rare, Aberystwyth. (H. J. F.)
Crenilabrus melops, Cuvier. Two young specimens, Aberystwyth.
(F.S.W.) One, February, 1913. (C.L.W.) Summer, 1910.
Ctenolabrus rupestris, Linneus. Fairly common. (H.J.F.; F.S. W.)
Cyclopterus lumpus, Linneus. Fairly common. (H.J.F.; F.S. W.)
Trachinus draco, Linneus. Rare, Aberdovey. (H. J. F.)
Zeugopterus punctatus, Bloch. Occasional. (H.J.F.; C.L.W.) One
specimen was obtained clinging to the under surface of a stone by
means of the margins of the body. I have since seen this species
adhere to the sides of a tank in Plymouth Aquarium, in a similar
manner. (C. L. W.)
NEW SERIES.—VOL. xX. NO. 1. NOVEMBER, 1913. H
Peli
The Distribution of some Littoral Trochide and
Littorinide in Cardigan Bay.
By
Chas. L. Walton,
University College of Wales, Aberystwyth.
THE physical characteristics of the Bay having been set out in the pre-
ceding paper, it will not be necessary to repeat that description here, since
only special local features will be dealt with, as occasion arises. Peculiari-
ties of distribution had been noted for the Trochide and Littorinide,
and it was with a view to obtaining further information as to the opera-
tion of local littoral conditions and their effects upon the fauna that
these groups were more particularly examined. These notes detail some
of the peculiarities, and outline what are believed to be the controlling
causes, at any rate for the central area of the Bay. It would be of great
interest to know whether similar peculiarities have been, or can be,
observed for other areas of coast. The region discussed lies between
Gwhert-on-Sea at the mouth of the Teifi, to the south; and a point a
few miles beyond Pwllheli to the north. The portion more closely
examined extends from near Llanrhystyd, some eight miles south of
Aberystwyth, to Mochras, a few miles south of Harlech. Some observa-
tions were also made about Portmadoc, Borth-y-Gest, and Pwllheli in
the northern part of the Bay; and about New Quay, and the mouth of
the Teifi to the south, the most southerly beg some miles below Cemmes
Head.
Much of the coast is difficult of access, and the investigation has been
going on for a number of years.
The following species have been observed living within tide marks :—
TROCHID.
SOME LITTORAL TROCHIDA AND LITTORINIDZ IN CARDIGAN BAY. 115
LITTORINID.
GENERAL DistTRIBUTION.
(1) G. cineraria.—This species is rare throughout the whole of the
region examined. ‘Two large living specimens were obtained after
- careful search, in the coves at Gwhert; these coves are situated sea-
ward of the bar, and their general fauna is rich (for Cardigan Bay).
Two small specimens were also found, under stones about eight miles
south of Aberystwyth. Dead shells are not infrequent, so that this
“species may be more abundant below tide marks.
(2) G. umbilicata is, in certain districts, exceedingly abundant ; but
at Gwhert, in the coves above mentioned, I found but two. In New Quay
Bay it abounds, also locally from Llanrhystyd (and probably between
there and New Quay) to within some two miles of the River Ystwyth,
where it gradually dies out. Further north it reappears near Towyn
to the north of the Dysynni. It is abundant about Mochras, and occurs
at Y-Gamlas on the Zostera beds beyond Pwllheli. There it is accom-
panied by (3) G. magus, the only locality for this fine species that has
so far been noted in the Bay.
(4) M. crassa has very much the same distribution as G. umbilicata,
but its range is more restricted, and always lies within the area occupied
by that species. Both are often exceedingly abundant for considerable
distances.
(5) C. zizyphinus.—So far only one small living specimen has been
recorded, and that at Aberystwyth, where no other species of the Tro-
chide exist. It probably occurs in deeper water.
(6) Lattorina littorea has a wide distribution, but is more especially
abundant and much larger in certain places.
(7) L. neritoides is, as elsewhere, very local. Its distribution around
the Bay appears to be quite normal and to be governed by its usual
requirements ; a rocky foreshore, affording crevices just above high-
water mark, and not exposed to the midday sun and the resulting desic-
cation. Given these conditions, it often will occur in very restricted
areas. South of Aberystwyth, the foreshore for considerable distances
is chiefly smooth rock, with a steep seaward inclination. One or two
large squared masses of fallen cliff are situated just about high-water
116 CHAS. L.. WALTON.
mark, and their stratified wall-like sides afford crevices, inhabited by
this species and L. rudis. L. neritovdes, however, only occurs on the
upper portions, and on the N. and E. faces. A few may be observed
on the S.E. also, but this is exceptional. I have seen practically the
same thing in similar positions on the Devon coast. On the sea walls of
the promenade at Aberystwyth, this species occurs, chiefly where the
rays of the summer sun will not strike about midday.
(8) L. obtusata occurs throughout the littoral region examined wherever
Fucus grows, and hence is the most thoroughly persistent form.
(9) L. rudis.—This also is generally present, and frequently exceed-
ingly abundant. It usually accompanies L. littorea in its distribution,
though at a somewhat different level. These two frequently appear and
disappear simultaneously, but one or other may be locally dominant.
VERTICAL DISTRIBUTION.
The distribution of the species may also be considered vertically, that
is, In zones. These zones, of course, overlap considerably and are seldom
all well developed, or even present in any given locality. By contrasting
varying localities a general succession appears. This is not by any means
arbitrary, as some of these zones may occur intermixed at times, particu-
larly in the case of M. crassa, L. littorea, and L. obtusata. L. neritoides is
constant when conditions permit, and L. obtusata is dependent on the
presence of Fucoid Algz. C. zizyphinus has occurred once, but im its
normal position.
Allowing for local differentiation and overlap, the succession is, more
or less, as follows :—
L. neritoides.
L. rudis.
| M. crassa.
L. obtusata.
lz. lattorea.
G. umbilicata. G. maqus.
G. cineraria.
C. zizyphinus.
The succession of the Littorinide can be best followed in the Aberyst-
wyth district, where the Trochide are absent.
On the sea wall of the promenade below the University the following
succession can be observed :—
(a) Barren stonework.
(b) Zone of L. neritordes.
SOME LITTORAL TROCHID AND LITTORINIDZ IN CARDIGAN BAY. 117
(c) Zone of small green Alg@ and many L. rudis.
(d) ,, ,, few scattered Fucoids and a few L. rudis.
(e) ,, ., thick coating of Fucus and a few L. obtusata.
(f) Base of wall, with pools at foot, with Enteromorpha, Ulva, etc., and
LL. littorea.
M. crassa is local in Cardigan Bay, but often extremely abundant ;
and in the area south of Aberystwyth exhibits a striking peculiarity in
that it there breaks zone by following fresh-water influence, sometimes
as far as the low-water mark of spring-tide ; it is then often of remark-
able size. Proceeding southwards from Aberystwyth, the mouths of the
Rheidol and Ystwyth and a storm beach are passed, and a high
slaty cliff with eroded rocky foreshore is reached. About halfway
around this headland (Allt Wen), i.e. two miles from Aberystwyth,
G. umbilicatus puts in an appearance, at first only sporadically, two or
three small individuals here and there. As it becomes more numerous,
M. crassa also appears, and both increase rapidly to the south of the
headland, where the clifis are composed of glacial drift. A number of
springs flow down, and in one or two localities fresh water percolates
through a shingle bank on the foreshore, and affects more or less the
whole of the lower rocky and stony portions of the tidal region, which is
there mainly composed of boulders covered to some extent by Alge.
Where there is fresh-water influence, M. crassa follows it. Streamlets
often follow a kind of channel or gutter, where the boulders lie less
thickly, and the shore level is somewhat lower. In these channels,
M. crassa swarms upon the nearly bare boulders, and extends almost
to low water. G. umbilicata is seldom to be observed within the fresh-
water influence, although abundant close by. Where a section of the
shore is affected by fresh water, M. crassa tends to become abundant
throughout. It appears to feed upon minute Alg@, and I am indebted to
Dr. Fleure for a recent attempt to determine the food of this species :
all that could be made out, however, was that “the contents of the gut
consisted of finely triturated vegetable matter, too fragmentary for
identification.” H. J. Fleure and M. M. Gettings state (Q.J.M.S., 1907),
“ T. crassus |M. crassa] is found to some extent with the previous species
[G. umbilicata], but it lives, for the most part, near high-tide level, so
much so that specimens may remain for a considerable time in corners
washed only by high spring-tides. It crawls over the rocks chiefly at half-
tide level, but is more lethargic than 7. obliquatus |G. umbilicata], and
less inclmed to browse on the larger Alge. During stormy periods,
especially in winter, numbers may be found huddled in sheltered nooks,
118 CHAS. L. WALTON.
often with a number of Lattorina littorea as companions. As is well
known, the spire of 7. obliquatus is much lower than that of 7’. crassus,
and this is probably correlated with the greater activity of the former
in the shore zone, where a high spire would give too much purchase to
a side blow from a wave.” Recent observations lead to the same con-
clusions: the animals crowd the tops of the boulders in calm summer
weather, and in winter tend to occupy the sides and angles of boulders
and reef-pools.
It is evident that in this region Trochus is extending its range
northward. Quite recently Mr. W. Whitehouse informed me that he
had seen specimens on the Aberystwyth side of Allt Wen. This I
found to be the case, as I found a colony of G. umbilicata and one
specimen of G. cinerarva about the spot indicated. This is well to the
north of any other record, but is close to an isolated patch of boulder
clay. I have examined this spot at intervals ever since 1906, and
Prof. Fleure knew it well for some years before that, and no Trochi
have ever been seen there.
A remarkable influence of fresh water in larger volume upon the littoral
Mollusca has been noted, about the mouths of several of the smaller
rivers. It is particularly noticeable for some half-mile or so on either
side of the mouth of the Afon Wyre, near Llanrhystyd. The clifis there-
abouts are very low, and composed of glacial drift, with the usual result
that the foreshore consists of shingle, while the lower portion of the
tidal region is occupied by boulders of medium size. These extend to
low-water mark, but pass into sand and shingle both to the N. and to
the §8.; and this boulder area is fairly well covered with Algal
growth. The river debouches upon a shingle bed, and spreads out in a
fan-like manner over the boulders ; and, to judge by the distribution of
mussels, would appear, as usual, to trend up-coast, at least durmg some
states of the tide. To the south of the river where the boulder area
commences (and, indeed, throughout the area) the zones of L. neritoides
and the upper portion of that of L. rudis are absent owing to the presence
of shingle. The boulders are at first considerably incrusted with Sabel-
larva, and no Mollusca are present except a few specimens of Patella,
probably owing to the proximity of much sand and shingle. As the
boulder area widens G. umbilicata appears, and rapidly becomes abundant.
That lack of shelter and attrition are the excluding factors is borne out
by the fact that, where Gibbula first appears, the shells of many are much
worn and eroded, and in several cases actually broken. I examined
certainly 1000 Gibbulas, and only discovered two specimens of cineraria.
SOME LITTORAL TROCHIDA AND LITTORINIDZ IN CARDIGAN BAY. 119
Both were small, flattened, and occurred beneath stones. L. obtusata
accompanies Fucus, and is the most persistent species throughout.
L. littorea appears about the same time as G. wmbilicata, but does not
become abundant until fresh-water influence is an appreciable factor ;
it then increases in number and size. G. umbilicata is dominant for a
considerable distance, but as the river is approached, M. crassa appears,
here one and there one, amidst the crowds of Gibbula. Those first noticed
are rather small, but there is a gradual increase in size and abundance
until it equals G. wmbelicata in numbers. That species then dies out as
fresh water is approached, and is replaced by a rather squat, solid,
smooth form of L. rudis, which im its turn rapidly becomes -larger and
more numerous, while M. crassa, after being a dominant species for ?
while, dies out in its turn. Then for a space, L. rudis and L. littorea alone
occupy the ground; but both are absent from the actual flow of the
stream. On the northern side of the river, mussels are abundant in the
crevices of the stones for some distance along the shore, and are accom-
panied by L. rudis and L. littorea. Then, as the mussels disappear,
M. crassa reappears, and in company with the Littorias becomes very
abundant. G. wmbilicata recommences by degrees, increases in numbers,
and with M. crassa continues until the boulder area once more gives
place to shingle.
This lateral distribution or zonmg may be expressed thus (the order
in each instance is that of abundance) :—
ie, 2; 3: 4,
G. umbilicata. G. umbilicata. G. umbilicata. G. umbilicata.
L. littorea. L. littorea. M. crassa.
G. cineraria. M. crassa. L. littorea.
G. cineraria.
Lattorina obtusata.
5; 6. | (i 8. Z
M. crassa. L. rudis. | L. rudis. L. rudis-littorea.
L. littorea. L. littorea. L. littorea.
G. umbilicata. M. crassa. | M. crassa.
L. rudis. G. umbilicata. |
. . . Lattorina obtusata.
I; 2. | 3. | 4,
an littorea- L. rudis-litto-\L. rudis-L. litto-- M. crassa. | L. littorea-
| rudis. | rea. M. crassa. rea. M. crassa. G.umbilicata.| rudis.
120 CHAS. L. WALTON.
THE LITTORINIDA.
It may be mentioned that the shells of L. obtusata often bear a striking
resemblance in both form and colour to the vesicles and conceptacles of
the species of Fucus upon which they live; so much so, in fact, that
when collecting this species, I have more than once mistaken the vesicles
of the Alge@ for the shell of the Mollusc.
The conceptacles of all the species of Fucus are of shades varying from
white to bright yellow, and, indeed, the whole of the parts of the plant
exposed to sunlight are frequently much lighter in hue than the more
sheltered portions, which are usually dark brown or olive. One would
expect that the lighter coloured forms of L. obtusata would tend to occur
upon the surface, and the darker among the masses of the plant. I have
made a considerable number of observations in the district with the
object of testing this idea. What I have found is, that the darkest varieties
are seldom found upon the surface of the Algal masses, and that the
majority of varieties are found in abundance crawling on the exterior,
but are often in harmony with their surroundings. It may be mentioned
that many shells which appear out of harmony, are not so in reality, the
change of colour being due to drying of the shell durmg low water. The
ereatest resemblance is between the light brown and _ yellow-shelled
varieties and the vesicles of F’. vesiculosus and between the colour of the
frond and the ordinary brown and olive shells. Bright yellow Littorinas
may be found at times upon the dark stems of the Algz, and are then
very conspicuous. I do not find the yellow variety to be really common
in the district.
The Littorinide persist in the areas devoid of Trochide ; and, as has
already been stated, L. obtusata appears to be less affected by the adverse
conditions than the other species ; this is in all probability largely due
to the protection afforded it by the food plant, and its shell-characters.
L. rudis and L. littorea, are neither so large, so numerous, nor so evenly
distributed as in the areas where Trochide are abundant. Several
varieties of Z.rudis occur in Cardigan Bay, and of these tenebrosa, Montagu,
has so far only been found under stones some three miles south of Aber-
ystwyth on a portion of the shore influenced by fresh water. This mn-
fluence was sufficiently strong to attract a number of eels which were also
hiding under the stones. Tryon describes the variety as “thi, whorls
rounded, with elevated spire, brownish or yellowish, usually tessellated
with white.” In the Aberystwyth specimens the ribbings of the shell
are not very strong, and the colour olive-green to greyish. The chequered
appearance is due to the presence of a series of short white streaks dis-
SOME LITTORAL TROCHID AND LITTORINID/ IN CARDIGAN BAY. 121
posed in a spiral sequence ; these white marks, alternating in each turn
of the spiral produce a chequered appearance. The usual forms, semzlis
and levis of Jeffreys, were both present in the same locality. The variety
patula, Thorpe, is sometimes abundant on steep rocks at the foot of cliffs,
somewhat influenced by fresh-water springs, and may be yellow, olive-
green, pale greenish white, black and white in bands, or pinkish ; com-
pressa, Jefireys, occurs a little to the south of Aberystwyth.
The complete sequence of species of Littorma may be interrupted,
and a barren area may occur between the cliff rocks and the lower tidal
reefs, owing to a belt of shingle. The result of this truncation of zone
is that the upper portion of the rudis zone may be absent except here and
there where conditions allow ; while below the break, rudis and littorea
may be found together in quantity, giving the impression that the latter
is above its usual horizon.
Dr. Fleure considers that L. rudis spawns largely in the shelter afforded
by the interior of dead Balanus, and I have found many of the young of
both rudis and littoralis so small as to be just recognizable clustered
within the angles of empty Balanus. The absence of Balanus from the
rudis zone may also have a limiting effect, locally, on the distribution of
the species. A curious and interesting form of Molluscan association is
common on some parts of the cockle beds of the Dyfi estuary, and usually
on the more muddy areas. Scattered over from one to several acres in
such places, are clusters, or groups, composed primarily of one or more
mussels, attached to either various dead shells which lie upon the surface,
or to one or more living cockles of varying sizes. The latter occupy their
usual positions in the sand, thus anchoring the mussels. Upon the cockles
erow trailing tufts of various green Alga, and clinging to the mass are
generally several individuals of L. littorea and L. rudis, more often the
former. Within the mass, amongst the byssal threads of the mussels,
one or more specimens of Macoma balthica are frequently to be found.
There are often a dozen individuals, belonging to five species of Mollusca,
involved in these clusters.
Factors GOVERNING DISTRIBUTION.
The facts concerning distribution, association, etc., are matters of
observation, record, and comparison; the causes of distribution are
problems of a much more difficult nature, and require careful considera-
tion following wide investigation. With regard to the distribution of
the Trochide in Cardigan Bay, it is not yet possible to state that the
s y
problem has been completely elucidated. It would appear, however,
122 CHAS. L. WALTON.
that there is a correlation between such distribution and shore dramage.
The barren area receives most of its shore dramage from lime-free slates
and grits, while the ‘‘ Trochus ” areas receive water from boulder clay in
the southern, and the same, and igneous rocks, in the northern portions
of the Bay. The streamlets followed by M. crassa drain from boulder
clay. An attempt was made to obtain additional data by a comparison
of the Alge from various portions of the Aberystwyth district. Certain
differences were discovered (see list of Alg@), but none of them appear to
have any direct connection with the Mollusca under consideration ; and
the evidence afforded is thus more cumulative than decisive. The
boulder clays of different districts appear to have different lime con-
tents. The water of the New Quay district is “ hard,’ fruit trees
grow well there and the drifts probably contain lime, whereas the
boulder clay from the region drained by the Ystwyth has been analysed
by Dr. T. C. James, and found to be quite devoid of lime. The northerly
drift along the coast has been mentioned already ; and it is noteworthy
that dramage from the areas containing lime would tend to mfluence the
coast some distance northward on that account. The limeless dramage
of the Ystwyth, moreover, coincides with an area of slate and shale rocks ;
and this is the most barren as regards Trochidee. The reappearance of the
Trochide to the north again coincides with the reappearance of boulder
clay, and river dramage from districts containing volcanic rock, ete.
BIBLIOGRAPHY.
1853. Forsrs, E., and Hantry, 8. History of British Mollusca. London,
Van Voorst.
1886-92. Reports upon the Fauna of Liverpool Bay and the Neighbouring
Seas, L.M.B.C.
1887. Tryon, G. W. Manual of Conchology, Vol. LX, p. 229, ete.
1896. The Marine Zoology, Botany, and Geology of the Irish Sea; Fourth
and Final Report of the Committee.
1904. “Plymouth Marine Invertebrate Fauna,’ Journ. Marine Biological
Assoc., Vol. VII, No. 2.
1907. Frirure, H. J., and Gerrines, M. M. ‘Notes on Common Species
of Trochus,” Q.J.M.S., 1907, pp. 459-472.
1911. Watton, C. L., Firurs, H. J., and Wricut, F.S. National Union
of Teachers Souvenir Volume: Aberystwyth Conference.
“Notes on the Marine Life of the Shores of Cardiganshire,”
pp. 97-110.
[ #23 ]
Marine Biological Association of the
United Kingdom.
Report of the Council, 1912.
The Council and Officers.
The Council have to record with regret the death of the Duke of
Abercorn, who had been a Vice-President since the foundation of the
Association, of Professor Adam Sedgwick, F.R.s., for many years a
member of the Council, and of Mr. G. H. Drew, who became a member
of Council in June last.
The thanks of the Council are due to the President and Council of .
the Royal Society for the use of the rooms in which their meetings
have been held.
The Plymouth Laboratory.
The work done during the spring of 1912 to the front walls and roof
of the building has proved efficient in keeping out the damp, and as
regards the structure everything appears now to be in good order.
The machinery and apparatus both of the Aquarium and the Laboratory
have been maintained in an efficient state.
The Boats.
Owing to the state of the finances the steamer Ozthona was laid up
somewhat earlier than usual. The collecting work has since been
done by the sailing boat Anton Dohrn and the small motor-boat which
was presented to the Laboratory by Colonel G. M. Giles.
It has been decided to sell the Anton Dohrn, which has done good
service during the last ten years, and to replace her by a new sailing
boat of similar type.
The Staff.
The staff at work at the Laboratory has consisted of the Director,
Dr. E. J. Allen; Hydrographer, Mr. D. J. Matthews, and three
124 REPORT OF THE COUNCIL.
Naturalists, Messrs. L. R. Crawshay, J. H. Orton and R. S. Clark.
The latter has recently been appointed to make investigations on the
biology of marketable fishes.
Occupation of Tables.
The following Naturalists have occupied tables at the Plymouth
Laboratory since the last report was presented to the Association :—
Prof. CHas. CHILTON, D.sc., New Zealand (Amphipoda).
J. CLARK, D.Sc., Kilmarnock (Crustacea).
W. DE Morean, Plymouth (Protozoa).
G. H. Drew, B.a., Plymouth (Tissue Growth).
F. Martin Duncan, Oxted (Photography of Marine Animals).
H. M. Fucus, Cambridge (Echinoderm Development).
J. Gray, Cambridge (Echinoderm Development).
H. Hewry, u.p., Sheffield (Parasitic Protozoa).
G. J. Hii, London (General Zoology).
H. B. Jonnsron, Oundle (General Zoology).
S. P. Kramer, M.pD., New York (Elasmobranchs).
Miss D. Jorpan Lioyp, Cambridge (Echinoderm Development).
Mrs. MatrHews, Plymouth (Development of Aleyonium).
C, A. Newman, Oundle (General Zoology).
Guy DE Pirarp, Berne (Anemones).
C. SHEARER, M.A., Cambridge (Dinophilus and Echinoderm Development).
GEOFFREY SMITH, M.A., Oxford (Blood of Carcinus).
C. L. Wauton, Aberystwyth (Anemones).
General Work at the Plymouth Laboratory.
During the six months covered by the present report the staff
have for the most part been employed in a continuation of the re-
searches then described. The Director’s experiments on the conditions.
of growth of plankton diatoms have made considerable progress and
results of great scientific interest are promised. Mr. Matthews’s in-
vestigations on the chemistry of sea-water have to some extent been
interrupted by the preparation of a report on the hydrographical work
of the Irish Fishery Department, by whom Mr. Matthews is in part
employed.
Mr. L. R. Crawshay’s report on the fauna of the deeper portion of
the English Channel to the south-west of the Eddystone has been
published in the Journal of the Association. This report, in conjunc-
tion with the previous papers by Mr. Crawshay and Mr. Worth on
the bottom-deposits of this region, forms a valuable addition to our
knowledge of the English Channel both from the biological and
geological points of view.
REPORT OF THE COUNCIL. 5
Mr. Crawshay has since the completion of this work been engaged
with considerable success in experimental work on rearing copepods
and other plankton animals in the Laboratory, with a view to working
out the details of their life-histories, a subject upon which very much
remains to be done.
In addition to extending the general faunistic records of the Plymouth
neighbourhood Mr. J. H. Orton has been specially studying the rate of
growth of invertebrates. A large collection of material and of data
has been brought together, and an important contribution to our
knowledge of this comparatively unworked subject is anticipated when
the work is reported upon.
Mr. R. 8S. Clark is continuing the investigations on the mackerel
fisheries off the Cornish coast which were commenced some years ago
by the Director and Mr. Bullen. There seems reason to hope that a
thorough investigation of the causes which induce the migrations of
this fish may make it possible to assist the fishermen in finding the
shoals.
The work of Messrs. Shearer, De Morgan and Fuchs, who have
been further assisted by Messrs. J. Gray and L. Doncaster and Miss
D. Jordan Lloyd, on the hybridization of Echinoids and the rearing of
parthenogenetic echinoderm larve, has been published in a number of
papers in the Quarterly Journal of Microscopical Science, which have
attracted considerable attention.
Mrs. Matthews has been investigating the development of Aleyoniuim
and has been able to obtain all stages from the fertilized egg to the
fixed polyp in considerable numbers.
Mrs. Sexton and Mrs. Matthews have been studying a species of
brackish-water Gammarus with a view to determining the nature of
the variations in structure or appearance which are brought about by
changes in the conditions under which the animals live. They have
succeeded in rearing five generations in about six months, and they
now have the animals living and breeding both in entirely fresh water
and in sea-water of normal salinity.
Published Memoirs.
The following papers, either wholly or in part the outcome of work
done at the Laboratory, have been published elsewhere than in the
Journal of the Association :—
DoncastER, L., and Gray, J. Cytological Observations on the Early Stages of
Segmentation of Echinus Hybrids. Quart. Journ. Micr. Sci., vol. 58, 1912-13,
pp. 483-509.
Fucus, H. M. On Echinoderm Hybridisation, Rept. Brit. Assoc, Ady. Sci., 1912.
126 REPORT OF THE COUNGCITI.
Fucus, H. M. The Inheritance of the Aboral Process of the Echinocardium Pluteus.
Arch. f. Dwele. d. Organismen., Bd. 35, pp. 558-68.
Gray, J. The Effects of Hypertonic oie upon the Eggs of Echinus. Proce.
Camb. Phil. Soc., vol. 17, 1913, pp. 1-6.
Gray, J. The Effects of Hypertonic Solutions wpon the Fertilised Eggs of Echinus
(E. esculentus and E. acutus). Quart. Journ. Micr. Sci., vol. 58, 1912-18, pp. 447-81.
Ikepa, I. Studies on some Sporozoan parasites of Sipunculoids. I. The Life-
History of « New Actinomyxidian, Tetractinomyxon intermedium g. et sp. nov. Arch.
f. Protistenkunde, Bd. 25, 1912, pp. 240-72.
Nicuoits, G, E. The Structure and Development of Reissner’s Fibre and the Sub-
commissural Organ. Quart. Journ. Micr, Sei., vol. 58, 1912, pp. 1-116.
Nicott, W. On two new Trematode Parasites from British Food-Fishes.
Parasitology, vol. 5, 1912, pp. 197-202.
Sexton, E. W. Some Brackish-water Amphipoda from the mouths of the Weser and
the Elbe, and from the Baltic. Proc. Zool. Soc., Lond., 1912, pp. 656-65.
SHEARER, C. The Problem of Sex Determination in Dinophilus gyrociliatus. Pt. I.
The Sexual Cycle. Quart. Journ. Micr. Sci., vol. 57, 1912, pp. 329-71.
SHEARER, C., DE Morean, W., and Fucus, H. M. On Paternal Characters in
Echinoid Hybrids. Quart. Journ, Micr. Sci., vol. 58, 1912, pp. 337-52.
SHEARER, C., and Lioyp, D. J. On methods of Producing Arteficial Parthenogenesis
in Echinus esculentus and the Rearing of the Parthenogenetic plutei through Metamor-
phosis. Quart. Journ. Micr. Sci., vol. 58, 1912-13, pp. 5238-49. —
WisnHorr, G. Die Systematik der Nemertinen. Zoologischen Anzeiger,
Bd. 40, October, 1912.
The Library.
The thanks of the Association are due for the following books and
current numbers of periodicals presented to the Library during the
period June 1st to Dec. 31st, 1912 :—
Académie Imp. des Sciences de St. Pétersbourg. Bulletin.
American Museum of Natural History. Annual Report.
American Microscopical Society. Transactions.
American Philosophical Society. Proceedings.
Armstrong College. Calendar.
Arendals Fiskeriselskab Beretning.
Australian Museum. Records.
Bergens Museum. Aarbok.
Skrifter.
Bernice Pauahi Bishop Museum, Honolulu. Occasional Papers.
Board of Agriculture and Fisheries. Annual Report of Proceedings under
Acts relating to Sea Fisheries.
Return of Sea Fisheries, England and Wales.
— Report of Proceedings of Annual Meeting.
—— Report upon the Epidemic amongst Salmonidee in the summer of 1911.
—— Statistical Tables,
—— Memorandum on German Eel Culture.
Boston Society of Natural History. Proceedings.
REPORT OF THE COUNCIL. L27
British Museum. Catalogue of the Cheetopoda in the British Museum
(Natural History). Arenicolide.
—— National Antarctic Expedition, 1901-4. Zoology and Botany.
Bulletin Scientifique de la France et de la Belgique.
Bureau of Science, Philippine Islands. Journal of Science.
California Academy of Sciences. Proceedings.
Club Montanyene, Barcelona. Butllett.
College of Science, Tokyo. Journai.
Colombo Museum. Spolia Zeylanica.
R. Comitato Talassografico Italiano. Bollettino.
—— Memoria.
Bollettino delle Crociere Periodiche.
Comité du Laboratoire de Carlsberg. Comptes Rendus.
Conchological Society of Great Britain and Ireland. Journal of Conchology.
Connecticut Academy of Arts and Sciences. Transactions.
Conseil perm. internat. pour Exploration de la Mer. Bulletin Hydro-
graphique,
—— Bulletin Planktonique.
—— Bulletin Statistique.
—— Publications de Circonstance.
Rapports et Proces-Verbaux des Réunions.
Cornwall Sea Fisheries Committee. Reports.
Cuerpo de Ingenieros de Minas del Peru. Boletin.
Dept. of Agriculture, etc., Ireland. Report.
Dept. of Commerce and Labor, Bureau of Fisheries, U.S.A. Bulletin.
—— Pamphlets.
Dept. of Marine and Fisheries, Canada. Annual Report.
Dept. of Trade and Customs, Melbourne. Zoological Results of the Fishing
Experiments carried out by the F.I.S. Endeavour 1909-10.
Deutschen Fischerei-Vereins. Zeitschrift fiir Fischerei.
Deutscher Seefischerei-Verein. Mitteilungen.
Dove Marine Laboratory. Report.
Falmouth Observatory. Meteorological and Magnetic Reports.
La Feuille des Jeunes Naturalistes.
Field Museum of Natural History. Publications.
Finnlandische Hydrographisch-Biologische Untersuchungen. Abhandlungen.
Tidvattnen i Ostersjon och Finska viken. By R. Witting.
Fisheries Society of Japan. Journal.
The Fisherman’s Nautical Almanac. By O. T. Olsen.
Fishery Board of Scotland. Annual Report.
—— Scientific Investigations.
—— Fisheries and Marine Motor Exhibition, Copenhagen, 1912. Report on
Fishing Boat Motor Engines exhibited, ete. By Capt. J. R. M’Ewan.
Fiskeri-Beretning.
Government Museum, Madras. Report.
Guernsey Society of Natural Science. Report and Transactions.
Illinois State Laboratory of Natural History. Bulletin.
Imperial Bureau of Fisheries, Japan. Report.
Imperial Fisheries Institute, Japan. Journal.
—— Report.
8 REPORT OF THE COUNCIL.
Indian Museum. An Account of the Deep-Sea Asteroidea collected by the
R.I.M.S.S. Investigator. By R. Koehler.
—— An Account of the Shallow Water Asteroidea. By R. Koehler.
—— An Account of the Littoral Holothurioidea. By R. Koehler and C, Vaney.
—— Catalogue of the Indian Decapod Crustacea. By A. Alcock.
—— The Aleyonarians of the Deep Sea. By J. A. Thomson and W. D.
Henderson.
—— The Aleyonarians of the Littoral Area. By J. A. Thomson and J. J.
Simpson,
Institut fiir Meereskunde, Berlin. Veriffentlichungen.
Institut Océanographique. Annales.
Institut de Zoologie, Montpellier. Travaux.
R. Irish Academy. Proceedings. :
Kommission zur wissenschaftlichen Untersuchung der Deutschen Meere, ete.
Wissenschaftliche Meeresuntersuchungen.
Kommissionen fiir Havunderségelser, Copenhagen. Meddelelser.
K. Bayerischen Akademie der Wissenschaften, Miinchen. Abhandlungen.
—— Sitzungsberichte.
Kgl. Danske Videnskabernes Selskab. Oversigt.
Laboratoire Biologique de St. Pétersbourg. Bulletin.
Laguna Marine Laboratory. Report.
Lancashire Sea Fisheries Laboratory. Report.
Lancashire and Western Sea Fisheries. Superintendent’s Report.
Linnean Society. Transactions.
Linnean Society of New South Wales. Proceedings.
Liverpool Biological Society. Proceedings and Transactions.
Los Angeles Zoological Society. Proceedings.
Marine Biological Association of the West of Scotland. Report.
Marine Biological Laboratory, Woods Hole. Biological Bulletin.
Marine Biological Station, Port Erin. Report.
Mark Anniversary Volume.
Mededeelingen over Visscherij.
Meteorological Office. Barometer Manual-
—— Geophysical Manual.
—— Monthly Pilot Charts.
—— Annual Report of the Committee.
R. Microscopical Society. Journal,
Ministére de Instruction publique, France. Deuxiéme Expédition Antarctique
Frangaise (1908-1910).
Musée Océanographique de Monaco, Bulletin.
Museo Nacional, Buenos Aires. Anales.
Museo Zoologico, Napoli. Annuario.
Museum of Comparative Zoology, Harvard College. Bulletin.
Memoirs.
Report.
Muséum National d’Histoire Naturelle, Paris. Bulletin.
The Museums Journal.
Nederlandsche Dierkundige Vereeniging. Tijdschrift.
—— Verslag.
New York Academy of Sciences. Annals.
REPORT OF THE COUNCIL. 129
New York Zoological Society. Bulletin.
—— Report.
—— Zoologica.
New Zealand Institute. Transactions and Proceedings.
Norges Fiskeristyrelse. Aarsberetning vedkommende Norges Fiskerier.
La Nuova Notarisia.
Oberlin College. The Wilson Bulletin.
Owens College, Manchester. The Dorsal Vibrate Fin of the Rockling (Motella).
By J. 8S. Thomson.
—— Observations on living Gorgonias (Gorgonia verrucosa) occurring in the
English Channel. By J. 8. Thomson.
—— Observations on some Aleyonaria from Singapore. By E. W. Shann.
— The Presence of Maxillule in Larvee of Dytiscide. By J. Mangan.
— Structure of the Alimentary Canal of the Stick-Insect, Bacillus rosii Fabr.
By A. E. Cameron.
Physiographiske Forening, Christiania. Nyt Magazin for Naturvidenskaberne.
Quarterly Journal of Microscopical Science. (Presented by Sir E. Ray
Lankester, K.C.B., F.R.S.)
Rijksinstituut voor het Onderzoek der Zee. Helder. Jaarboek.
Royal Society of Edinburgh. Proceedings.
—— Transactions.
Royal Society of London. Philosophical Transactions.
Proceedings.
Royal Society of Victoria. Proceedings.
Scottish Microscopical Society. Proceedings.
Selskabet for de Norske Fiskeriers Fremme. Norsk Fiskeritidende.
Smithsonian Institution. New Diptera from Panama. By J. R. Malloch.
—— A Study of the Salinity of the Surface Water in the North Pacific Ocean
and in the adjacent enclosed Seas. By A. H. Clark.
Societas pro Fauna et Flora Fennica. Acta.
Société Belge de Géologie, etc. Bulletin.
Société Centrale d’Aquiculture et de Péche. Bulletin,
Société ’Enseignement des Péches Maritimes. Bulletin Trimestriel.
Société Imp. Russe de Pisciculture et de Péche. Vyestnik R‘ibopom‘shlen-
nosti.
Société Zoologique de France. Bulletin.
South African Museum. Annals.
Kgl. Svenska Vetenskaps-Akademien. Arkiv for Botanik.
Arkiv for Zoologie.
—— Handlingar.
Tohoku Imperial University, Japan. Science Reports.
Torquay Natural History Society. Journal.
Transvaal Museum. Annals.
Tufts College. Studies.
United States National Herbarium. Contributions.
United States National Museum. Bulletin.
—— Proceedings.
R. Universit’ di Napoli. Lavori fatti nell’ Istituto di Anatomia comparata.
—— Apparati Reticolari Sarcolemma nella fibra muscolare cardiaca. By
M. Fedele.
NEW SERIES.—VOL. X. NO. 1, NOVEMBER, 1913. : I
13 REPORT OF THE COUNCIL.
R. Universita di Napoli. La morfologia della cromatina dal punto di vista
fisico. By P. Della Valle.
University of California. Publications. Zoology, Physiology, Botany.
University College Library, London. Catalogue.
University of Toronto. Studies.
Kgl. Vetenskaps Societeten, Upsala. Nova Acta.
Visscherij-Station, Batavia. Mededeelingen.
Zoological Museum, Copenhagen. The Danish Ingolf-Expedition.
Zoological Society of Japan. Annotationes Zoologicee Japonenses.
Zoological Society of London. Proceedings.
—— Transactions.
Zoologische Sammlung des Bayerischen Staates. Beitriige zur Naturgeschichte
Ostasiens.
Zoologisches Museum, Berlin. Bericht.
—— Mitteilungen.
Dr. H. R. Mill. Symons’s Meteorological Magazine.
Mrs. Hill. A number of works from the library of her brother, the late
W. I. Beaumont.
To the authors of the Memoirs mentioned below the thanks of the
Association are due for separate copies of their works presented to
the Library :—
Barroso, M. G. Briozoos de la Estacién de Biologia Maritima de Santander.
Billard, A. Hydroides de Roscoff.
Breitfuss, L. L. Wissenschaftlich-praktische Murman-Expedition. Bericht
iber die Tatigkeit pro 1905,
Buchanan, J. Y. Experimental Researches on the Specific Gravity and the
Displacement of some Saline Solutions.
Burrows, M. T. A Method of Furnishing a Continuous Supply of New
Medium to a Tissue Culture in Vitro.
— Rhythmische Kontraktionen der isolieren Herzmuskelzelle ausserhalb
des Organismus.
— The Growth of Tissues of the Chick Embryo outside the Animal Body,
with Special Reference to the Nervous System.
Carrel, A., and Burrows, M. T. Cultivation of Tissues in Vitro and its
Technique.
Cultivation in Vitro of the Thyroid Gland.
Cultivation in Vitro of Malignant Tumors.
Caullery, M. Présence de Physalies et de Vélelles dans le Pas-de-Calais au
début d’Avril, 1912.
Clark, J. An Annotated List of Cornish Fishes.
Notes on Cornish Crustacea. I. Brachyura and Macrura.
Cotton, A. D. Clare Island Survey. Marine Alge.
Crossland, C. Supplement to the “‘ Physical Description of Khor Dongonab,
Red Sea.”
Dakin, W. J. Aquatic animals and their environment. The Constitution of
the external medium and its effect upon the blood.
Davenport, C. B. Light thrown by the Experimental Study of Heredity upom
the Factors and Methods of Evolution.
REPORT OF THE COUNCIL. Best
Donnison, H. Report on Crab Investigations.
Drew, G. H. An Experimental Investigation of the Cytological Changes.
produced in Epithelial Cells by long-continued Irritation.
Fabre-Domergue. Epuration bactérienne des Huitres par la stabulation en eau
de mer artificielle filtrée.
—— Nouvelles expériences sur l’épuration bactériologique des huitres en eau
filtrée.
—— Instructions pour l’établissement et l’emploi de bassins de stabulation
destinés & ’épuration des Huitres et autres Mollesques comestibles.
Farran, G. P. Plankton from Christmas Island, Indian Ocean. I. On Cope-
poda of the Family Coryceide.
—— Clare Island Survey. Decapoda.
Fauvel, P. Sur quelques Néréidiens (Perinereis Marionti Aud. Edw. P.
macropus Clap. Neanthes succinea Leuck.),
Freund, L. Krankheiten der Fische.
Gemmill, J. F. Laboratory Aquarium Notes.
Aerator suitable for Laboratory Aquaria.
—— Notes on the Adult Anatomy of Solaster endeca (Forbes).
— The Locomotor Function of the Lantern in Echinus, with Observations
on other Allied Lantern Activities.
The Development of the Starfish, Solaster endeca (Forbes).
Goodrich, E.S. Nerilla an Archiannelid.
—— Observations on the Nephridia of the Alciopine.
Hartmeyer, R. Revision von Heller’s Ascidien aus der Adria.
Helland-Hansen, B., and Nansen, F. The Sea West of Spitsbergen. The
Oceanographic Observations of the Isachsen Spitsbergen Expedition in
1910.
Heron-Allen, E., and Earland, A, On some Foraminifera from the North Sea,
etc., dredged by the Fisheries Cruiser Goldseeker (International North Sea
Investigations—Scotland). I. On some New Astrorhizide and their Shell
Structure.
Hornell, J. New Cestodes from Indian Fishes.
Hoyle, W. E. The Cephalopoda of the Scottish National Antarctic Expedition.
Ikeda, I. Studies on some Sporozoan parasites of Sipunculoids. I. The Life-
History of a new Actinomyxidian, Tetractinomyxon intermedium g. et
sp. nov.
Issel, R. Biologica neritica mediterranea. Il bentos animale delle foglie di
Posidonia studiato dal punto di vista bionomico,
—— Biologica neritica mediterranea, Richerche di etologia sull’ Isopodo
tubicolo. Zenobiana prismatica (Risso).
Kofoid, C. A. Protozoa.
Korotneff, A. A. Die Planarien des Baikal-Sees (Tricladen).
Lee, A. B. L’étape strepsinématique des auxocytes males de |’Escargot.
Lohmann, H. Die Probleme der modernen Planktonforschung.
M‘Intosh, W. C. Notes from Gatty Marine Laboratory.
Man, J. G. de. Sur quelques ‘“ Paleemonidee” et sur une espéce de “Penaeus”
de l’Afrique occidentale avec des observations sur le “ Paleemon (Eupale-
mon) acanthurus” Wiegm,. de ’Amérique du Sud.
—— OUdontopharyna longicaudata n. g.n.sp. Eine neue Form von Anguil-
luliden,
132
REPORT OF THE COUNCIL.
Mines, G. R. An accessory time signal for use in experiments where the
recording apparatus is not run continuously.
Functional Analysis by the action of electrolytes.
— Some observations on electrocardiograms of cold blooded animals.
Some observations on Electrograms of the Frog’s Heart.
—— Calcium Salts in Relation to Neuromuscular Mechanisms.
Nicoll, W. On two new Trematode Parasites from British Food-Fishes.
Nilsson, D. Beitriage zur Kenntnis des Nerven-systems der Polychaeten.
Orton, J. H. An Account of the Natural History of the Slipper Limpet.
Pax, F. Hypertrophie bei Actinienlarven.
—— La paléontologie et la distribution géographique des Actinies.
— — Aktinienstudien.
—— Vorarbeiten zu einer Revision der Familie Actiniide.
— Studien an Westindischen Actinien.
— Aktinien der Aru-Inseln.
—— Die Aktinien der Ostafrikanischen Inseln.
—— Die Steinkorallen der Deutsche Siidpolar-Expedition, 1901-1908.
—— Anthozoa. Die Aktinien-fauna Westafrikas.
Popta, C. M. L. Fortsetzung der Beschreibung von neuen Fischarten der
Sunda-Expedition.
—— Die geographische Verbreitung der Siisswasserfische zwischen Asien und
Australien.
Reinke, E. A Preliminary Account of the Development of the Apyrene
Spermatozoa in Strombus and of the Nurse-cells in Littorina.
Schaxel, J. Zur Analysis des Spiraltypus der Annelidenfurchung bei normalen
und abnormen Verlauf.
—— Weitere Untersuchungen iiber die Eibildung der Meduse Pelagia.
Schmidt, J. Contributions to the biology of some North Atlantic species
of Eels.
Sexton, E. W. Some Brackish-Water Amphipoda from the Mouths of the
Weser and the Elbe, and from the Baltic.
Shearer, C. The Problem of Sex Determination in Dinophilus qyrociliatus.
Pt. I. The Sexual Cycle.
Tattersall, W. M. Clare Island Survey. Cumacea, Schizopoda, etc.
Van Name, W. G. Simple Ascidians of the Coasts of New England and
Neighbouring British Provinces.
Viguier, C. Nouvelles études sur le Plankton de la Baie d’Alger.
Donations and Receipts.
The receipts for the seven months ending December 31st, 1912,
include the grants from His Majesty’s Treasury (£1000) and the
Board of Agriculture and Fisheries, Development Fund (£500), Special
Donations (£26), Annual Subscriptions (£71), Rent of Tables in the
Laboratory (£86), Sale of Specimens (£299), Admission to Tank Room
(£81).
REPORT OF THE COUNCIL. 133
Vice-Presidents, Officers, and Council.
The following is the list of gentlemen proposed by the Council for
election for the year 1913-14 :—
President.
Sir E. Ray Lanxestser, K.C.B., LL.D., F.B.S.
Vice-Presidents.
The Duke of Beprorp, K.G. The Right Hon. Aust—EN CHAMBER-
The Earl of Ducts, F.R.S. LAIN, M.P.
The Earl of SrrapproKkg, C.V.O., C.B. W. Astor, Esq., M.P.
Lord Avesury, F.R.S. G. A. BouLrenesr, Esq., F.R.S.
Lord WatsIncHAM, F.R.S. | , Current Expenditure :—
Salaries and Wages—
Directout(Hallk Vicar) rescue cee eaten teesicnencenees 100 0 0
iy droora ph enter esan sec seerete eco shh ot seeae rere sonstenst 87 10 0
Naturalist (iver Months) \is.secesse-tesceete doc-eceselaa see 104 3 4
NMI GIUL INALEERIISE, 2fic. ccddeionsicascnersvisenssedaeeecpusens 98 4 0
ASSIS LANIEPNALOTA ISG. cacecsecilececcler snes cleceir ee eleeleseicese lil @ ©
Salaries, Wages, and Compensation paid ............... 353 12 9
844 101
Less Compensation recovered from Employers’ Lia-
ODM, CO SOREOLN coocadnbonconessogaoondodenéonsoapegasac 24 3 0
hey 72) Le? 13g NEARS 439 nsonbasodeodosonde aogoobseabedonbadoRstoNe
Pita years sssoetecns concen tees esses ator e cian eles eceetelsjerecien sae 46 4 8
JOE) ADV OTE ALES RO) Os leer seogcocusseurronoone tece Coe qonbos inant OMEZ EG
POU AL cscs se snca cee cew acco anasas evan siesjemateeeesenssewise sete g0 i
SFESSI SH] OS tonnes sce soet see ee cee caine sete seraseoaneoneecssmernenets 4 8 10
Buildings and Public Tank Room—
GasmaWratersand: Coals ees nc ccescsioscssiienesauneaeteeaseaeens ail 8} D
Stockineanks; and Weeding vsesce.scceasccneteeececsed se 50) (04
Maintenance angeen wal Si ruccsnsccas-s-scceceeaccensecns 184 2 1
Rent. ates, laxes, and. Insurance s..c.scceceseeestaces 3 1
IY if
esse Admission) touwlanksRooml \o.cnsccereecedsecsese st 80 14 2
Laboratory, Boats, and Sundry Expenses—
Glass, Apparatus, and Chemicals................cc0ceeeeees 104 15 10
TOS: SSEIGSS ApEn RE PEE DP CE ORE ODOT PRT Cray OPE AN 49 14 8
55 1 2
Unc haser Ole SPECIMENS pur mcrase esse adceeece eee eeeee: al al
Maintenance and Renewal of Boats, Nets,
Gearemetce Masacmecssndossnenseocecttenessaste 139 5 10
SIFESSE SL CSNCLCH ar os eo eis en ias rece tarse reso 95 18 8 43 7 2
MInetOTsB OMLS meme acer shee ecn ten nastier a kasaeuetaemrtonweeees 22 2 2
Insurancelofsiy. OuhOnd tc sceerececece- se 32 13 0
esSMNe Date rene. tadeeanctocesee oun deswacecot 1g} ls) US 7
CoalF and Water for Steamer -2....:52:.+-0+-0teeeeen ae 30 15 9
Stationery, Office Expenses, Carriage, Printing, etc. 8110 5
3802 14 4
GEESE VOGHTS) UTOWIU CIS! ene adennaccboscEaduob ab soonEoboEdgeECoe 299 0 10
», Bank Interest
», Balance :—
CASheat eDANKerSMmescete Ceres cance ceo ncanscre ceo mens 135 11 10
Gash vr NaN ees addon te atoee «och shee desteeick anes 5 ae ee 10 5 10
342 9
(OV A2
211 13
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145 17
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£1,683 18
[436° 4
Marine Biological Association of the United Kingdom.
eas ae
OF
Governors, Founders, and Members.
lst OCTOBER, 1913.
* Member of Council. + Vice-President. + President.
Ann. signifies that the Member is liable to an Annual Subscription of One Guinea.
C. signifies that he has paid a Composition Fee of Fifteen Guineas in lieu of Annual
Subscription.
1884
1884
1884
1884
1884
1884
1884
1884
1884
1884
1884
1884
I.— Governors.
The British Association for the Advancement of Science, Burlington
F018; WY ABs ch csciomwmnneh ualusledveeonepennnnd tas de tee ghee aaa aan eae ee eee £500
The University ot Oxford , «2, ojscises. dec sagusdechenoceaden te ae tee eoreee £500
The University of Cambridee.. sic\.2..22..002 ccs co vaeesecesdvemenseaemonenpee £500
The Worshipful Company of Clothworkers, 41, Mincing Lane, E.C. £500
The Worshipful Company of Fishmongers, London Bridge, E.C. ... £10,705
Bayly, Roberthikthe late). .cavcentetecnacesassesaetansen dteeesstes emcee eoaeeee £1000
Bayly, siohnsihe late) <... connccccsece coe ean-baceaeerometes, smaseade oaselesmanenes £600
Thomacson, JeP. (the late) 5.25. Sssessenenas vses ante scenes seen aweeesesasexenc £970
G. P. Bidder, Esq., Cavendish Corner, Cambridge .....s.cscesecescsecseeceee £1500
II.— Founders.
the Corporation‘ot the (Cityeot Mondom 025... see-teGaeeeaaeeeee £210
The Worshipful Company of Mercers, Mercers’ Hall, Cheapside ...... £341 5s.
The Worshipful Company of Goldsmiths, Goldsmiths’ Hall, E.C....... £100
The Royal Microscopical Society, 20, Hanover Square, W........s..c00e £100
The Royal Society, Burlington House, Piccadilly, W. ...cccsececeeeeeeeees £350
The Zoological Society, Regent’s Park, London, N.W. ..........ceceeeeeee £100
Bulteel, Thos, (the Wate)” .. ao.ccsssesasoscemaan aceon ceceesreesretee -eacemensresae £100
Burdett-Coutts, W. L. A. Bartlett, 1, Stratton Street, Piccadilly, W.... £100
Crisp, Sir Frank, Bart., Treas. Linn. Soc., 17, Throgmorton Avenue, H.C. £100
Daubeny,; Capiaim Giles Aq Aes .ccrsacecstensnsseusanscanaeenemacenenn-tsasehasns £100
Eddy, J. Ray, The Grange, Carleton, Skipton ........c2ccececssecscesesenevace £100
Gassiott;.John#P ithe date) ccaseccceccace machen ameeslnstsices ate sscmeerischnneies £100
1884
1884
1884
1884
1884
1884
1884
1885
1887
1888
1888
1889
1889
1889
1890
1902
1909
+1910
1912
19138
1913
1897
1900
#1895
1889
1910
1892
+1911
1910
1902
1884
1908
1884
1884
1884
1885
1884
+1907
1905
1910
1912
1910
1910
#1884
LIST OF GOVERNORS, FOUNDERS, AND MEMBERS. 137
Lankester, Sir E. Ray, K.C.B., F.R.S., 29, Thurloe Place, South
ASE RG CON SG 2c aux cetocereme eae spite Aniec ne sae aa bictsbtisev ademas: esse £100
(ehenith. Hon. Lord Mashama(the lacey «sd aivsesccnar es nonin anest Socciiesshsaecs £100
Moseley: Prot. Hi N..) BL RiSs (ieee iy oe oresencscciegaescherkasceaane sna ana £100
The Rt: Hon: Lord Avebury, F.R.S. (the'late) .....,..2.c0s0.<.csessecenses £100
Poulton, Prof. Edward B., M.A., F.R.S., Wykeham House, Oxford ...... £100
Romaness GJ, Tabs, WeRS. (Chie late) no..: sscteeaceescesast ceeee's uid se £100
Worthington, shames (he: abe): ce. ctsuiet asecesasnoneee doceeBinnsoruere aceast £100
Derbys thevlate: Baele Qk weave hosute-coaatucgcesace ake: - dltdodonschiacannasacoade £100
Weldons. Promo. Ps Ra chenios (thie late). io. ys. cccus.cep sees areece bancemesene £100
Bury, Henry, M.A., Mayfield House, Farnham, Swrrey.........cccccceeeees £100
The Worshipful Company of Drapers, Drapers’ Hall, E.C............604. £315
The Worshipful Company of Grocers, Poultry, H.C. oc... cece eee eees £120
Miompson, caretlemry, spark, (phev lave) vir0. cjcsss.d-aemenvects ani ste rns fenk ox £110
Revelstoke: Uhetate sl onde .4.ceisc-csuaad sctis chan asenas nt soos on etaw snk ssdeae dens £100
Riches) ewe nAL Kale lis SS emleyy TCTs) cae cmlesn senor arrive peas aernos ls dese £230
Jurney, Robert, Ingham Old Hall, Stalham, Norfolk ......c.ccc0ccceeeee £105
Harding, Colonel W., The Hall, Madingley, Cumbridge .........0.000000 £100
Murray, Sir John, K.C.B., F.R.S., Challenger Lodge, Wardie, Edinburgh £100
Swithinbank, H., F.R.S.E., F.R.G.S., Denham Court, Denham, Bucks. £100
Shearer, Dr. Cresswell, 30, Thompson’s Lane, Cambridge ...........0.0000 £100
III.—Members. .
Adams, Alfred, M.B., B.Ch., Oxon. Looe, Cornwalt.......ccc0cc.csascce0s0 Ann.
Adams, W. R., Howfield, 111, Denmark Hill, Camberwell, London, S.H, Ann.
Ader Dre We. Meresanevbain: 2H ast Agrectie nt .uncsteaacensnseesemeea so sttas Ann.
Allen, ds d.; D:Se, the Laboratory, Plynputh \..t.nc.sisceseeuse-deseece ses Ann,
Alward, G. L., Enfield Villa, Humberstone Avenue, Waltham, Grimsby Ann,
Ashworth, J. H.,.D.Se:, The University, Hdinburgh 3.0 sR Se AP Ann,
Saunders, J. T., B.A., Christ's College, Cambridge ......ss.csscecscosencnsens Ann.
Scharff, Robert F., Ph.D., Science and Art Museum, Dublin............65 Ann.
embers tN. Wis Uther ULL, SLAP OTOs, ca. eataraastsne-Cdaaeelscncre xaneatektsecerars Ann,
Schuster, Edgar, D.Sc., 110, Banbury Road, Oxford ...........csceececeenes Ann.
Nelater, W. L., Odiham= Priory, Wonch field, ONS. c000 i000snceeeces vrassoeeo Ann.
Scott, D. H., M.A., Ph.D., F.R.S., Hast Oakley House, Oakley, Hants.... C.
SeOtiase Mm Bouncer orice. Melee aesseeue de ecawas sci waS-marmessanceetSe Ann.
Serpell, E. W., Loughtonhurst, West Cliff Gardens, Bournemouth......... £50
pexton, LE: B.,3, Queen*Anne Terrace, Plymoutit® vi .%3..sccnssnsesses-o-0- Ann.
Shaw, Joseph, K.C., Bryanston Square, London, W. .......c.c.ceeeseeoeeees £13
sleldoni Miss Inliansiegh Pork, Bideford ¢ ie .cc. veins s U.
Sinclair, Willam F., 102, Cheyne Walk, Chelsea, S.W.......... Jisieaalestreces C
Skinners, the Worshipful Company of, Skinners’ Hall, B.C. ............ 42
Slade, Rear-Admiral Sir E. J: W., K.C.LE., K.C.V.O., 128, Church
ENECb en COMM POC AGU WO NGO I, VIC srt sascktoe hemes ncceaatadoet quaesies Seas s C.
HbA Greolrey: Wi, NGI) COLE OST ORM: mas sate. sacs jaaciasaetsicannseacatoeeee Ann,
Spencer, Prof. W. Baldwin, M.A.,F.R.S., University of Victoria, Melbourne Ann,
Sprague, Thomas Bond, M.A., LL.D., 29, Buckingham Terrace, Edinburgh Ann,
Straker, J., LL.M., F.Z.S., Oxford and Cambridge Club, S.W. .........4.. C.
Thompson, Prof. D’Arcy W., C.B., University College, Dundee............ Ann
Thompson, Sir H. F., Bart., 9, Kensington Park Gardens, London, W. Aun,
Thornycroft, Sir John I., F.R.S., Hyot Villa, Chiswick Mall ............ Ann.
Tims, H. W. Marett, M.D., Bedford College, Regent’s Park, London, N.W. Ann,
Torquay Natural History Society, Torquay ...c.0....ccsccecssesnscaseveeee Ann.
142
*1897
1910
1891
1884
1884
1910
+1884
1912
1906
1909
1909
1906
1910
1900
1908
1884
1913
1900
1905
1898
1889
1904
1904
1904
1904
1904
1904
1889
1904
1889
1901
1889
1890
1890
LIST OF GOVERNORS, FOUNDERS, AND MEMBERS.
Travers, J. A., Tortugton House, Arundel ere tees beer on esas Aaeaieeas Ann.
Travers, Miss R..C., Tortengton House, Arundel soe... 0. can tdecwsesescsecars Ann,
Vaughan, Henry pic h.bssecsse concerti men ecaecs te eee eee ade ioe Macks C.
Walker, Alfred, O.; Ulcombe Place, Matdstone ............scsscecseneesenees Ann,
Walker, P.uF’,-386; Prince's Gardensy SW 2 vss cstsecekoopnea eos eee Ann.
Wallace, W., D.Sc., 43, Parliament Street, London, S.W. ...........0.0000 Ann.
Walsingham, The Rt. Hon. Lord, F.R.S., Merton Hall, Thetford......... £20
Ward, Dr. Francis:-20, “Park Road, Ipswich | 2o..sc.teaseesweaseceen tees Ann,
Waterhouse, N. E., 3, Fredericks Place, Old Jewry, London, H.C. ...... Ann.
Waters, Arthur W., F.L.S., Alderley, McKinley Road, Bournemouth ... Ann.
Watson, A. T., Southwold, Tapton Crescent Road, Sheffield..............005 Ann.
Weldon; iMacs, Merton lied, “Ontong, eosttratt.ssccce- eae m nase ene Ann,
Willes, W. A., Elmwood, Cranborne Road, Bournemouth .......cce.eeceeee Ann.
Willey, A., D.Sc., F.R.S., McGill University, Montreal, Canada ......... Ann,
Williamson, Lieut. H. A., R.N., The Central Flying School, Upavon ... Ann.
Wilson, Scott, B., Heather Bank, Weybridge Heath ........-..s.0ecsceeeeee C.
WiceeW. Hs 34, George Streets Plymouth... occosx cessor ene «cence Sem eawesane Ann.
Wolfenden, 2s IN. MAD. cos. oc poetics ete Sgece ss cactus ss stan cone eee Ann.
Woolf, M. Yeatman, Wimpole House, Wimpole Street, London, W....... Ann.
Worth, R..H., 42, George Street, Plymouth 5... ..cc0ce00s0-c00c) snoeepocneee Ann.
IV.—Associate Members.
Caux, J. W. de, Great Yarmouth.
Donnison, F., Deep Sea Fishing Co., Boston.
Edwards, W. C., Mercantile Marine Office, St. Andrew’s Dock, Hull.
Freeth, A. J., Fish Quay, North Shields.
Hurrell, H. E., 25, Regent Street, Yarmouth.
Inskip, H. E., Capt., R.N., Harbour Master’s Office, Ramsgate.
Johnson, A., Fishmongers’ Company, Billingsgate Market, London, E.C.
Olsen, O. T., F.L.S., F.R.G.S., Fish Dock Road, Great Grimsby.
Patterson, Arthur, [bis House, Great Yarmouth.
Ridge, B. J., Newlyn, Penzance.
Sanders, W. J., Rockvall, Brixham.
Sinel, Joseph, 8, Springfield Cottages, Springfield Road, Jersey, C.I.
Spencer, R. L., L. and N.W. Depét, Guernsey.
Wells, W., The Aquartwm, Brighton.
pias 4
List of Publications Recording the Results of Researches carried
out under the Auspices of the Marine Biological Association
of the United Kingdom in their Laboratory at Plymouth or
on the North Sea Coast from 1886-1913.
THE following list has been classified, so far as practicable, according to
subjects, in order that it may be useful for purposes of reference. The
list does not include publications recording the results of observations
made on material supplied by the Association to workers in different
parts of the country, of which a considerable amount is sent out each
year.
In attempting to distinguish between economic and more purely
scientific publications considerable difficulty has been experienced ;
indeed such a distinction is in reality impossible, since all researches
bearing on the distribution and habits of marine life of any kind have
a more or less direct bearing on fishery problems. All papers dealing
with the distribution, habits, and young stages of fishes have been
included in the economic division, whether the fishes are themselves
marketable or not.
September, 1913.
Economic Publications.
1. GENERAL.
The Natural History of the Marketable Marine Fishes of the British Islands.
Prepared by order of the Council of the Marine Biological Association
especially for the use of those interested in the Sea-Fishing Industries.
By J. T. Cunningham, m.a. With a preface by E. Ray Lankester, m.a.,
LL.D., F.R.S. London: Macmillan and Co., Ltd., 1896.
144 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
Eggs and Larve.
The Ovaries of Fishes. By J. T. Cunningham, m.a. Journ. M.B.A. N.S. i.
1893-95, p. 154.
On the Histology of the Ovary and of the Ovarian Ova in certain Marine
Fishes. By J. T. Cunningham, m.a. Quart. Journ. Micr. Sci. XL.
1897) palo:
A Contribution to the Knowledge of the Ovary and Intra-ovarian Egg in
Teleosteans (with Plates XI. and XIT.). By W. L. Calderwood. Journ.
M.B.A. N.S. ii. 1891-92, p. 298.
Observations on Ovarian Ova and Follicles in certain Teleostean and Elasmo-
branch Fishes. By W. Wallace, m.a. Quart. Journ. Micr. Sci., vol.
xlvu. p. 161.
A Record of the Teleostean Eggs and Larvee observed at Plymouth in 1897.
By HE: W. b. Molt and 8: D. Scott, pa. Journ. MBA INS]
1897-99, p. 156.
Studies on the Reproduction and Development of Teleostean Fishes occurring
in the neighbourhood of Plymouth (with Plates I-VI.). By J. T.
Cunningham, m.a. Journ. M.B.A. N.S.1. 1889-90, p. 10.
On Some Larval Stages of Fishes (with Plates III. and IV.). By J. T.
Cunningham, u.a. Journ. M.B.A. N.S. n. 1891-92, p. 68.
‘On Some Disputed Points in Teleostean Embryology. By J. T. Cunningham,
m.A. Ann. and Mag. Nat. Hist. 1891.
Recherches sur la Reproduction des Poissons osseux. Par E. W. L. Holt.
Ann. Mus. Hist. Nat. Marseille, v., 1899.
Preliminary notes on the Reproduction of Teleostean Fishes in the South-
Western District. By E. W. L. Holt. Jown. M.B.A. NS. v.
1897-99, p. 41.
Notes on the Reproduction of Teleostean Fishes in the South-Western Dis-
trict. By E. W. L. Holt and L. W. Byrne, B.a. Journ. M.B.A. N.S. v.
1897-99, p. 333.
Report on the Kggs and Larvee of Teleostean Fishes observed at Plymouth in
the Spring of 1902. By F. Balfour Browne, m.a. Journ. M.B.A. vi.
1903, p. 598.
Notes on the Reproduction of Teleostean Fishes in the South-Western District.
By EK. W. L. Holt. Journ. M.B.A. N.S. v. 1897-99, p. 107.
Report on a Collection of Very Young Fishes obtained by Dr. G. H, Fowler in
the Faeroé Channel. By E. W. L. Holt. Proceed. Zool. Soc., London.
1898, p. 550.
Report on the Results of the Fish-Kgg Cruise made by the s.s. Hualey in
June, 1909. By H. J. Buchanan Wollaston. Internat. Fish. Investi-
gations. Mar. Biol. Assoc. Report HI. 1906-08 (Cd. 5546). 1911,
p. 207.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 145
Notes on Teleostean Ova and Larvee observed at Plymouth in Spring and
Summer, 1909. By A. E. Hefford, p.sc. Journ. M.B.A. N.S. ix.
1910-13, p. 1.
Age, Growth, and Maturity.
The Rate of Growth of some Sea Fishes and their Distribution at Different
Ages. By J. T. Cunningham, m.a. Journ. M.B.A. N.S. 1. 1891-92,
p-. 95.
On the rate of Growth of some Sea Fishes and the Age and Size at which they
begin to breed. By J. T. Cunningham, m.a. Journ. M.B.A. N.S. un.
1891-92, p. 222.
Report on the Probable Ages of Young Fish collected by Mr. Holt in the
North Sea. By J. T. Cunningham, m.a. Journ. M.B.A. N.S. u.
1891-92, p. 344.
On the Relation of Size to Sexual Maturity in Pleuronectids. (North Sea
Investigations.) By E. W. L. Holt. Journ. M.B.A. N.S. i. 1891-92,
p- 363.
On the Relation of Size to Sexual Maturity in Round-fish. (North Sea
Investigations.) By E. W. L. Holt. Journ. M.B.A. N.S. in. 1893-95,
Day fo:
On the Relations of the Generative Organs and of the Sexes in some Fishes.
_ (North Sea Investigations.) By J.T. Cunningham, m.a. Journ. M.B.A.
N.S. iv. 1895-97, p. 28.
Hybridism in Marine Fishes. By H. M. Kyle, p.sc. Journ. M.B.A. vi.
1903, p. 623.
Destruction of Immature Fish.
An Examination of the Present State of the Grimsby Trawl Fishery, with
especial reference to the Destruction of Immature Fish. By E. W. L.
Holt. Journ. M.B.A. N.S. ii. 1893-95, p. 339. (Cf. N.S.iv. 1895-97,
p. 410.) Also issued as a separate publication.
Destruction of Immature Fish. By G.C. Bourne, m.a. Journ. M.B.A. N.S. 1.
1889-90, p. 153.
On the Destruction of Immature Fish in the North Sea. Remedial Measures.
(North Sea Investigations.) By E. W. L. Holt. Journ. M.B.A. N.S. ii.
1891-92, pp. 380, 388.
The Immature Fish Question. By J. T. Cunningham, m.a. Journ. M.B.A.
N.S. ii. 1893-95, p. 54.
Growth and Distribution of Young Food-Fishes. By J. T. Cunningham, m.a.
Journ. M.B.A. N.S. ii. 1893-95, p. 272.
On the Destruction of Immature Fish in the North Sea. (North Sea In-
vestigations.) By EK. W. L. Holt. Journ. M.B.A. N.S. i. 1893-95,
pp. 81, 123, 169, 288.
NEW SERIES.—VOL. X. NO. 1. NOVEMBER, 1913. K
146 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES,
Statistics of Small Fish landed at Grimsby. (North Sea Investigations.)
By J. T. Cunningham, m.a. Journ. M.B.A. N.S.iv. 1895-97, p. 10.
Fish and Fishing Grounds.
The Impoverishment of the Sea. By W. Garstang, m.a. Journ. M.B.A.
NeSiv- 19005sp. 8:
Notes on the Fishing Industry of Plymouth. By Walter Heape, M.a. Journ.
M.B.A. Old Series. No.1. 1887, p. 45.
Monthly Reports on the Fishing in the neighbourhood of Plymouth (with
8 charts). By W. L. Calderwood. Journ. M.B.A. N.S. n. 1891-92,
p. 277 and p. 394. N.S. i. 1893-95, p. 107.
Preliminary Note on Trawling Experiments in certain Bays on the South
Coast of Devon. By F.B.Stead,B.a. Journ.M.B.A. N.S.iv. 1895-97,
p. JO:
Report on Trawling in Bays on the South Coast of Devon. By E. W. L.
Holt. Journ. M.B.A. N.S. v. 1897-99, p. 296.
Report on Trawling and other Investigations carried out in the Bays on the
South-east Coast of Devon during 1901 and 1902. Prepared for the
information of the Devon Sea Fisheries Committee by Walter Gar-
stang, M.A. Journ. M.B.A. N.S. vi. 1903, p. 435.
Notes on Rare or Interesting Specimens (Clupea alosa, Auais Rochev,
Thynnus thynnus, Myliobatis aquila). By J. T. Cunningham, M.a.
Journ. M.B.A. N.S.in. 1893-95, p. 274.
North Sea Investigations. Preliminary. By E. W. L. Holt. Journ. M.B.A.
N.S. ii. 1891-92, p. 216:
On the Territorial Fishing Ground of Scarborough and its Neighbourhood.
(North Sea Investigations.) By E. W. L. Holt. Journ. M.B.A. N.S. 11.
1893-95, p. 176.
On the Iceland Trawl Fishery, with some Remarks on the History of the
North Sea Trawling Grounds. (North Sea Investigations.) By EK. W. L.
Holt. Journ. M.B.A. N.S. i. 1893-95, p. 129.
Notes ona Fishing Voyage to the Barents Sea in August, 1907. By George T.
Atkinson. Journ. M.B.A. N.S. vin. 1907-10, p. 71.
Two Trips to the Eastern Grounds. (North Sea Investigations.) By J. T-
Cunningham, m.a. Journ. M.B.A. N.S. iv. 1895-97, p. 33.
Notes on the General Course of the Fishing. (North Sea Investigations.)
By J. T. Cunningham, m.a. Journ. M.B.A. N.S. iv. 1895-97, p. 12.
Observations at Sea and in the Markets—Grimsby, Scarborough, Hull,
Lowestoft. (North Sea Investigations.) By J. T. Cunningham, M.a.
Journ. M.B.A. N.S. iv. 1895-97, p. 108.
Account of a Voyage in the Smack Albert to the Newfoundland Fishing Banks.
By W. T. Grenfell, w.z.c.s. Journ. M.B.A. N.S. in. 1893-95, p. 143.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 147
The Fishes collected by the Hualey from the North Side of the Bay of Biscay
in August, 1906. By L. W. Byrne. Journ. M.B.A. N.S. vii. 1907-10,
ped,
Causes of the Observed Distribution of Fish in the North Sea. (North Sea
Investigations.) By J. T. Cunningham, m.a. Journ. M.B.A. N.S. iv.
1895-97, p. 133.
Physical and Biological Conditions in the North Sea. By J. T. Cunning-
ham, M.A. Journ. M.B.A. N.S. iv. 1895-97, p. 233.
General Report on the Fishery Investigations. By Walter Garstang, M.A.
Internat. Fish. Investigations. Mar. Biol. Assoc. Report I. 1902-03
(Cd. 2670). 1905, p. 1.
Report on Experiments with Marked Fish during 1902-03. By Walter Gar-
stang, M.A. Internat. Fish. Investigations, Mar. Biol. Assoc. Report I.
1902-03 (Cd. 2670). 1905, p. 13.
Report on the Trawling Investigations, 1902-03, with especial reference to the
distribution of the Plaice. By Walter Garstang, M.A. Internat. Fish.
Investigations, Mar. Biol. Assoc. Report I. 1902-03 (Cd. 2670). 1905,
pe OW;
Trawling Investigations, 1904-05. I. Particulars of Trawling Stations of
s.s. Huxley. IL. Detailed Measurements of Plaice caught at each haul
of the Commercial Trawls (s.s. Hualey). III. Summaries of hauls
made by s.s. Huzley, distinguishing the sizes of fish in 10-centimetre
groups. Internat. Fish. Investigations. Mar. Biol. Assoc. Report IL.,
Part 2. 1904-05 (Cd. 4641). 1909, p. 114.
Trawling Investigations, 1906-09. Internat. Fish. Investigations. Mar.
Biol. Assoc. Report IV. 1909 (Cd. 6125). 1912, p. 394.
Covered Net Experiments. By R. A. Todd, B.sc. Internat. Fish. Investiga-
tions. Mar. Biol. Assoc. Report III. 1906-08 (Cd. 5546). 1911, p. 177.
Report on the Lowestoft Sailing Trawler Records, 1903-06. By Rosa M.
Lee, M.A. Internat. Fish. Investigations. Mar. Biol. Assoc. Report IL.,
Part 2. 1904-05 (Cd. 4641). 1909, p. 89.
Comparative Notes on various Trawler Catches in the North Sea, including
some Steam Trawler Records for 1903 and 1905. By Rosa M. Lee, m.a.
Internat. Fish. Investigations. Mar. Biol. Assoc. Report IV. 1909
(Cd. 6125). 1912, p. 291.
Report on the Grimsby Steam Trawler Records, 1904-07. By Rosa M. Lee,
M.A. Internat. Fish. Investigations. Mar. Biol. Assoc. Report III.
1906-08 (Cd. 5546). 1911, p. 1.
Food and Feeding of Fishes.
Report on the Food of Fishes collected during 1903. By R. A. Todd, B.sc.
Internat. Fish. Investigations. Mar. Biol. Assoc. Report I. 1902-03.
(Cd. 2670). 1905, p. 227.
148 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
Second Report on the Food of Fishes (North Sea, 1904-1905). By R. A.
Todd, B.se. Internat. Fish. Investigations. Mar. Biol. Assoc. Report IL.,
Part 1. 1904-05 (Cd. 3837). 1907, p. 49.
The Sense-Organs and Perceptions of Fishes, with Remarks on the Supply of
Bait (with Plate XX.). By W. Bateson, M.a. Journ. M.B.A. N.S. 1.
1889-90, p. 225.
Experiments on the Production of Artificial Baits. By Frank Hughes.
Journ. M.B.A. N.S. 1. 1891-92, pp. 91 and 220.
Notes on How Fish Find Food. (Report on the occupation of Table.) By
Gregg Wilson, M.A., B.Sc. Report Brit. Assoc., 1893, p. 548.
Notes on the Invertebrate Fauna and Fish-food of the Bays between the
Start and Exmouth. By R. A. Todd, B.sc. Journ. M.B.A. NS. vi.
1903, p. 541.
Rearing Experiments.
Recent Experiments Relating to the Growth and Rearing of Food-fish at the
Laboratory. 11. The Rearing of Larval Fish. By J. T. Cunningham, m.a.
Journ. M.B.A. N.S.1. 1889-90, p. 370.
Breeding of Fish in the Aquarium. By J. T. Cunningham, m.a. Journ.
M.B.A. N.S. 11. 1891-92, p. 195.
Experiments on the Rearing of Fish-Larvee in the Season of 1894. By
J. T. Cunningham, m.a. Journ. M.B.A. N.S. in. 1893-95, p. 206.
Growth of Fishes in the Aquarium. By J. T. Cunningham, m.a. Journ.
M.B.A. N.S. iii. 1893-95, p. 167.
Rearing of Fish-Larve. By J. T. Cunningham, m.a. Journ. M.B.A.
N.S. i. 1893-95, p. 168.
Experiments on Sea-Fish Culture. By W. Garstang, m.a. Report Brit.
Assoc., 1899.
Preliminary Experiments on the Rearing of Sea-Fish Larvee. By W. Gar-
stang, M.A. Journ. M.B.A. N.S. vi. 1900, p. 70.
On the First Successful Experiment with Importation of European Sea Fishes
to Australian Waters. By H. C. Dannevig. Fisheries of New South
Wales. Annual Report for 1902, IT.
Diseases of Fish.
Some Notes on Parasitic and other Diseases of Fish. By G. H. Drew. Para-
sitology, vol. u. 1909, p. 193.
Some Notes on Parasitic and other Diseases of Fish. Second Series. By
G. H. Drew, B.A. Parasitology, vol. 1. 1910, p. 54.
Some Cases of New Growths in Fish. By G. H. Drew, B.A. Journ. M.B.A.
N.S. ix. 1910-13, p. 281.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 149
A List of Blood Parasites of Sea Fish taken at Plymouth. By Herbert
Henry, m.pv. Journ. M.B.A. N.S. ix. 1910-13, p. 570.
Note on Abnormal Pigmentation of a Whiting infected by Trematode larve.
By Prof. F. W. Gamble, r.x.s., and G. H. Drew, B.a. Journ. M.B.A.
N.S. ix. 1910-13, p. 243.
Miscellaneous.
Modes in which Fish are affected by Artificial Light. By W. Bateson, M.a.
Journ. M.B.A. N.S.1i. 1889-90, p. 216.
The Amount of Fat in Different Fishes. By F. Hughes. Journ. M.B.A.
N.S. ii. 1891-92, p. 196.
The Vernacular Names of Common Fishes. By J. T. Cunningham, M.a.
Journ. M.B.A. N.S.1. 1889-90, p. 92.
The Regulations of the Local Sea Fisheries Committees in England and
Wales. By E. J. Allen, B.sc. Journ. M.B.A. N.S.iv. 1895-97, p. 386.
Fishing Nets, with special reference to the Otter Trawl. By H. M. Kyle,
M.A., D.Sc. Journ. M.B.A. N.S. vi. 1903, p. 562.
2. Tuer Ee Faminy.
The Breeding of the Conger. By J. T. Cunningham, m.a. Journ. M.B.A.
Old Series. No. 2. 1888, p. 245.
On the Reproduction and Development of the Conger. By J. T. Cunning-
ham, M.A. Journ. M.B.A. N.S. 11. 1891-92, p. 16.
On a Specimen of Leptocephalus Morris. By J.T.Cunningham,m.a. Journ.
M.B.A. N.S.iv. 1895-97, p. 73.
Sudden Colour-changes in Conger. By W. Bateson, M.A. Journ. M.B.A.
N.S.1. 1889-90, p. 214.
The Larva of the Eel. By J. T. Cunningham, m.a. Journ. M.B.A. N/S. iii.
1893-95, p. 278.
The Reproductive Maturity of the Common Eel. By J. T. Cunningham, .a.
Journ. M.B.A. N.S.iv. 1895-97, p. 87.
Hels and Sticklebacks in Sea-water. By W. L. Calderwood. Journ. M.B.A.
N.S. i. 1891-99, p. 77.
Note on Muraena helena, Linn. By E. W. L. Holt. Journ. M.B.A. NS. v.
1897-99, p. 91.
3. Tue Herring FAmIty.
Anchovies in the English Channel (with an illustration in the text). By
J.T. Cunningham, m.a. Journ. M.B.A. N.S.i. 1889-90, p. 328.
Probable Relation between Temperature and the Annual Catch of Anchovies
in the Schelde District (with Plate XXIV.). By G. H. Fowler, B.a., PH.D.
Journ. M.B.A. N.S. i. 1889-90, p. 340.
150 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
Experiments on the Relative Abundance of Anchovies off the South Coast of
England. By W. L. Calderwood. Journ. M.B.A. N.S. 1. 1891-92,
p. 268.
The Migration of the Anchovy. By J. T. Cunningham, m.a. Journ. M.B.A-
N.S. ii. 1893-95, p. 300.
Ichthyological Contributions. iv. Growth of Young Herring in the Thames
Estuary. By J.T. Cunningham, m.a. Journ. M.B.A. N.S. 1. 1891-92,
p- 330.
On the Occurrence of Large Numbers of Larval Herrings at the Surface. By
Matthias Dunn. Journ. M.B.A. N.S. v. 1897-99, p. 184.
Notes on the Herring, Long-line and Pilchard Fisheries of Plymouth during
the Winter 1889-90. By W. Roach. Journ. M.B.A. N.S.1. 1889-90,
p. 382.
Notes on Herring, Long-line and Pilchard Fisheries of Plymouth. By W.
Roach. Journ. M.B.A. N.S. u. 1891-92, p. 180.
The Spawn of the Pilchard. By J. T. Cunningham, m.a. Journ. M.B.A.
Old Series, No. 2. 1888, p. 247.
The Reproduction and Growth of the Pilchard (with Plate X.). By J. T.
Cunningham, m.a. Journ. M.B.A. N.S. 1. 1891-92, p. 151.
Year-old Pilchards. By J. T. Cunningham, m.a. Journ. M.B.A. N.S. 11.
1891-92, p. 398.
The Life History of the Pilchard. By J. T. Cunningham, m.a. Journ.
M.B.A. N.S. iii. 1893-95, p. 148.
4. THE SALMon FAmMILy.
The Great Silver Smelt, Argentina silus, Nilsson, an addition to the List of
British Fishes. By E. W. L. Holt. Journ. M.B.A. N.S. v. 1897-99,
p. 341.
Grayling and Loch Leven Trout in Salt Water. By W. L. Calderwood.
Journ. M.B.A. N.S. v. 1891-92, p. 76.
On an Experiment in the Keeping of Salmon (Salmo salar) at the Plymouth
Laboratory. By L. R. Crawshay, m.a. Journ. M.B.A. NS. vin.
1907-10, p. 303.
5. FLat-FIisH Famity.
Diagnostic characters in Flat-fishes. By J. T. Cunningham, m.a. Journ.
M.B.A. N.S. v. 1893-95, p. 247. :
The Development of the Egg in Flat-fishes and Pipe-fishes. By J. T. Cunning-
ham, M.A. Journ. M.B.A. N.S. ii. 1893-95, p. 258.
A Treatise on the Common Sole (Solea vulgaris), considered both as an organism
and as a commodity. Prepared for the Marine Biological Association of
the United Kingdom. By J. T. Cunningham, m.a., Plymouth. Pub-
lished by the Association. 1890 (4to, pp. 147, with eighteen plates).
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. LSet
Reproductive Organs of the Common Sole. By J. T. Cunningham, M.a.
Journ. M.B.A. Old Series, No. 2. 1888, p. 248.
Ichthyological Contributions. ii. On a Stage in the Metamorphosis of Solea.
By J. T. Cunningham, m.a. Journ. M.B.A. N.S. 1. 1891-92, p. 327.
Report on the Spawning of the Common Sole in the Aquarium of the Marine
Biological Association’s Laboratory during April and May, 1895. By
G. W. Butler, p.a. Journ. M.B.A. N.S. iv. 1895-97, p. 3.
The Size of Mature Plaice, Turbot, and Brill on different Fishing Grounds.
(North Sea Investigations.) By J.T. Cunningham, m.a. Journ. M.B.A.
N.S. iv. 1895-97, p. 97.
On the Peculiarities of Plaice from different Fishing Grounds. By J. T.
Cunningham, m.a. Journ. M.B.A. N.S. iv. 1895-97, p. 315.
Observations on the Natural History of Plaice. (North Sea Investigations.)
By J. T. Cunningham, m.a. Journ. M.B.A. N.S.iv. 1895-97, p. 15.
Proposed Restrictions on the Landing of undersized Plaice in the light of
the New Evidence. (North Sea Investigations.) By J. T. Cunning-
ham, M.A. Journ. M.B.A. N.S.iv. 1895-97, p. 138.
On a Dwarf Variety of the Plaice, with some Remarks on the Occasional
Ciliation of the Scales in that Species. (North Sea Investigations.) By
E. W. L. Holt. Journ. M.B.A. N.S. ii. 1893-95, p. 194.
A Piebald Plaice. By J. T. Cunningham, m.a. Journ. M.B.A. N.S. m1.
1893-95, p. 271.
Variation und Asymetrie bei Pleuronectes flesus L. By G. Duncker. Wissen.
Meeresuntersuch. u. 1900, p. 333.
The Periodic Growth of Scales in Gadide and Pleuronectide as an Index of
Age. By J.S. Thomson. Journ. M.B.A. N.S. vi. 1902, p. 373.
Experiments in the Transplantation of Small Plaice to the Dogger Bank. By
Walter Garstang, M.A. Internat. Fish. Investigations. Mar. Biol. Assoc.
Report I. 1902-03 (Cd. 2670). 1905, p. 45.
Preliminary Investigations on the Age and Growth-Rate of Plaice. By
William Wallace, p.sc. Internat. Fish. Investigations. Mar. Biol. Assoc.
Report I. 1902-03 (Cd. 2670). 1905, p. 199.
An Experiment in the Transplantation of Plaice from the Barents Sea
(“ White Sea’’) to the North Sea. By George T. Atkinson. Journ.
M.B.A. N.S. vii. 1907-10, p. 502.
Report on the Age and Growth-Rate of Plaice in the Southern North Sea
as determined by the Investigation of Otoliths. By William Wallace,
p.sc. Internat. Fish. Investigations. Mar. Biol. Assoc. Report IL.,
Part 1. 1904-05 (Cd. 3837). 1907, p. 1.
Report on the Vitality of Trawl-caught Plaice. By J. O. Borley, M.a.
Internat. Fish. Investigations. Mar. Biol. Assoc. Report II., Part 2.
1904-05 (Cd. 4641). 1909, p. 1.
Report on the Size and Age of Plaice at Maturity in the North Sea and
152 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
English Channel. By William Wallace, p.sc. Internat. Fish. Investiga-
tions. Mar. Biol. Assoc. Report I., Part 2. 1904-05 (Cd. 4641). 1909,
p- ol.
The Distribution of the Plaice in the North Sea, Skagerak and Kattegat,
according to size, age, and frequency. By Walter Garstang. Conseil
Perm. Internat. Explor. Mer. Rapp. et Proc. Verb., vol. x1. 1909, p. 65.
The Proportionate Distribution of the Sexes of Plaice in the North Sea.
By A. KE. Hefford. Conseil Perm. Internat. Explor. Mer. Rapp. et
Proce: Verb.jivol. xi.» 1909-sp. 135: ;
Further Report on the Age and Growth-Rate of Plaice in the North Sea
and Knglish Channel, as determined by the Investigation of Otoliths.
By William Wallace, p.sc. Internat. Fish. Investigations. Mar. Biol.
Assoc. Report IH. 1906-08 (Cd. 5546). 1911, p. 109.
Report on the Experimental Transplantation of Plaice to the Dogger Bank
carried out by the Marine Biological Association in the years 1904-08.
By J. O. Borley, m.a. Internat. Fish. Investigations. Mar. Biol. Assoc.
Report IV. 1909 (Cd. 6125). 1912, p. 1.
A Comparison of the Condition of the Plaice of Different Regions as to
Weight. By J. O. Borley, m.a. Internat. Fish. Investigations. Mar.
Biol. Assoc. Report IV. 1909 (Cd. 6125). 1912, p. 81.
Report on Plaice Transplantation Experiments to Various Fishing Grounds
in the North Sea. By Rosa M. Lee, m.a., and George T. Atkinson.
Internat. Fish. Investigations. Mar. Biol. Assoc. Report IV. 1909
(Cdi=6125)2 1912p 107:
Report on Experiments with Marked Plaice during 1904 and 1905. By
Walter Garstang, M.A., D.Sc. Internat. Fish. Investigations. Mar.
Biol. Assoc. Report IV. 1909 (Cd. 6125). 1912, p. 153.
Report on the English Plaice Marking Experiments, 1906-08. By George T.
Atkinson. Internat. Fish. Investigations. Mar. Biol. Assoc. Report IV.
1909 (Cd. 6125). 1912, p. 225.
Note on Pleuronectes microcephalus, Donov. By E. W. L. Holt. Journ.
M.B.A. N.S. i. 1893-95, p. 121.
Rhombus maximus, Linn. (The Turbot.) By E. W. L. Holt. Journ. M.B.A.
N.S. 1. 1891-92, p. 399.
Note on some Supposed Hybrids between the Turbot and the Brill. (North
Sea Investigations.) By E. W. L. Holt. Journ. M.B.A. NS. iii.
1893-95, p. 292.
Note on Phrynorhombus unimaculatus, Risso. By E. W. L. Holt. Journ.
M:B.A. N.S. v. 1897-99, p. 343.
Hippoglossus vulgaris, Linn. (The Halibut.) By E. W. L. Holt. Journ.
M.B.A. N.S. 11. 1891-92, p. 399.
On Secondary Sexual Characters in Arnoglossus. By J.T. Cunningham, m.a.
Proceed. Zool. Soc. 1890, p. 540.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. Los
Note on Arnoglossus laterna, Walb. By E. W. L. Holt. Journ. M.B.A.
N.S. 1. 1891-92, p. 283.
Note on Arnoglossus Grohmanni, Bonaparte. By HE. W. L. Holt. Journ.
M.B.A. N.S. v. 1897-99, p. 89. -
Ichthyological Contributions. i. Zeugopterus norvegicus. (Giinther.) By
J. T. Cunningham, m.a. Journ. M.B.A. N.S. iu. 1891-92, p. 325.
Young Stages of Zeugopterus punctatus. By J.T. Cunningham, m.a. Journ.
M.B.A. N.S. ii. 1893-95, p. 202.
6. THE Cop Famity.
The Periodic Growth of Scales in Gadidw as an Index of Age. By J. Stuart
Thomson, F.u.s. Journ. M.B.A. N.S. vu. 1904-06, p. 1.
On the Cod Marking Experiments in the North Sea, conducted by the Marine
Biological Association of the United Kingdom from the s.s. Huzley
during 1904-1907. By J. O. Borley. Conseil Perm. Internat. Explor.
Mer. Rapp. et Proc. Verb., vol. x. 1909.
Note on Gadus Esmarki, Nilss. By E. W. L. Holt. Journ. M.B.A. N.S. u.
1891-92, p. 282.
Gadus Esmarkit, Nilsson, the Norway Pout, an addition to the Fish Fauna of
the English South-Western District. By E. W. L. Holt and Matthias
Dunn. Journ. M.B.A. N.S. v. 1897-99, p. 79.
Note on Phycis blennioides, Brinn. By E. W. L. Holt and W. L. Calder-
wood. Journ. M.B.A. N.S. u. 1891-92, p. 282.
Sense of Touch in the Rockling (Motella). By W. Bateson, M.a. Journ.
M.B.A. N.S. 1. 1889-90, p. 214.
Note on Motella cimbria, Linn. By E. W. L. Holt. Journ. M.B.A. N.S. v.
1897-99, p. 343.
Note on Raniceps raninus, Linn. By E. W. L. Holt. Journ. M.B.A. N.S. in.
1893-95, p. 119.
On some specimens of Molva abyssorum, Nilss., from Iceland and Faroé.
(North Sea Investigations.) By E. W. L. Holt. Journ. M.B.A. N.S. in.
1893-95, p. 200.
The Pelagic Post-larval Stages of the Atlantic Species of Gadus. By Johs.
Schmidt. Meddel. Komm. Havunders. Fiskeri., Bd. I. Nr. 4.
An Albino Hake (Merluccius merluccius). By W. Garstang. Journ. M.B.A.
NS: vi. - 1900! p.-275.
Motella fusca. A New British Record. By W. Garstang and F. Balfour
Browne. Journ. M.B.A. NS. vi. 1903, p. 626.
Gadus Esmarkii (Nilss.) in Shallow Water. By W. Garstang. Journ. M.B.A.
N.S. vi. 1900, p. 274.
7. THE STIcKLEBACK FamILy.
Note on Gastrosteus pungitius, Linn. By E. W. L. Holt. Journ. M.B.A.
N.S. in. 1893-95, p. 120.
154 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
8. CEPOLIDAE.
Note on Cepola rubescens, Linn. By E. W. L. Holt. Journ. M.B.A. N.S. v.
1897-99, p. 197.
9. Tue Bienny FAmIity.
Note on Lumpenus lampetraeformis, Walbaum. By E. W. L. Holt. Journ.
M.B.A. N.S. i. 1893-95, p. 120.
Note on the Young of Blennius galerita, Linn. (Montagu’s Blenny). By
L. W. Byrne. Journ. M.B.A. N.S. vi. 1902, p. 383.
10. THe LEPADOGASTER FAMILY.
On Lepadogaster. By E. W. L. Holt and L. W. Byrne, B.A. Proceed. Zool.
Soc. London. 1898, p. 589.
11. Tuer DraGonet FAmILy.
On the Breeding of Callionymus lyra in the Marine Biological Association’s
Aquarium at Plymouth. By E. W. L. Holt. Proceed. Zool. Soc. London
1898, p. 281.
The Egg and Larva of Callionymus lyra (with Plate V.). By J. T. Cunning:
ham, M.a. Journ. M.B.A. N.S.u. 1891-92, p. 89.
Note on Callionymus maculatus, Bonaparte. By E. W. L. Holt. Journ.
M.B.A. N.S. v. 1897-99, p. 90.
Note on Callionymus maculatus, Bonaparte. By E. W. L. Holt. Journ.
M.B.A. N.S. v. 1897-99, p. 343.
12. THe Gospy FaAmiIty.
Note on Gobius Jeffreysti, Giinther. By E. W. L. Holt. Journ. M.B.A.
N.S.ove 1697-99; paso.
The distribution of Crystallogobius Nilssonu. By J. T. Cunningham, M.A.
Journ. M.B.A. N.S. 11. 1891-92, p. 158.
Note on Crystallogobius Nilssonii, Diib. and Kor. By E. W. L. Holt. Journ.
M.B.A.. N.S. 0. 1891-92, p. 283.
Notes on Aphia pellucida, Nardo. By E. W. L. Holt. Journ. M.B.A. N.S. v.
1897-99, p. 89.
The British and Irish Gobies. Report on Sea and Inland Fisheries of Ireland
for 1901. By E. W. L. Holt and L. W. Byrne, 8.a. Part II., p. 37.
Published 1903.
13. Tue Joun Dory Famity.
The Habits of the Cuckoo or Boar Fish. By J. T. Cunningham, m.a. Journ.
M.B.A. Old Series, No. 2. 1888, p. 243.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 155
14. THe Horse-MackEREL F amity.
The Reproduction of Caranz trachurus, Linn., the Scad or Horse-Mackerel.
(North Sea Investigations.) By E. W. L. Holt. Journ. M.B.A. N.S. i.
1893-95, p. 190.
15. STROMATEIDAE.
On some Young Specimens of Centrolophus pomphilus (Art.) from the Coast .-
of Cornwall. By E. W. L. Holt. Journ. M.B.A. N.S. nu. 1891-92,
p- 265.
16. THe MacKEeREL FAMILy.
The Mackerel Fishery in the West of England in 1888. By B. J. Ridge.
Journ. M.B.A. N.S.1. 1889-90, p. 72.
The Plymouth Mackerel Fishery of 1880-90. From data collected by W.
Roach, Associate M.B.A. By W. L. Calderwood. Journ. M.B.A.
N.S. un. 1891-92, p. 4.
Ichthyological Contributions. ii. A Larval Stage of the Mackerel. By
J.T. Cunningham, m.a. Journ. M.B.A. N.S.u. 1891-92, p. 329.
Note on Scomber scomber, Linn. (The Mackerel.) By E. W. L. Holt. Journ.
WBA. ON.Sai.- 1891-92, 1p. 396.
Report on the Present State of Knowledge with Regard to the Habits and
Migrations of the Mackerel (Scomber scomber). By KE. J. Allen, B.sc.
Journ. M.B.A. N.S. v. 1897-99, p. 1.
Recherches sur Histoire Naturelle du Maquereau. By W. Garstang, M.a.
Congrés Internat. Péches Marit. Dieppe, 1898, p. 67.
Preliminary Note on the Races and Migrations of the Mackerel (Scomber
scomber). By W. Garstang, M.A. Rep. Brit. Assoc. Bristol, 1898,
p- 902.
The Variations, Races, and Migrations of the Mackerel. By W. Garstang,
M.A. Journ. M.BA. N.S. v. 1897-99, p. 235.
Plankton Studies in Relation to the Western Mackerel Fishery. By G. E.
Bullen. Journ. M.B.A. N.S. viii. 1907-10, p. 269.
Mackerel and Sunshine. By E. J. Allen, p.sc. Journ. M.B.A. N.S. vii.
1907-10, p. 394.
Some Notes upon the Feeding Habits of Mackerel and certain Clupeoids in
the English Channel. By G. E. Bullen. Journ. M.B.A. N.S.ix. 1910-
13, p. 394.
17. Tae WEEVER FAMILy.
Note on Trachinus draco, Linn. By E. W. L. Holt. Journ. M.B.A. N.S. v.
1897-99, p. 197.
156 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
18. ScoRPAENIDAE.
Note on Sebastes norvegicus, Ascan. By EH. W. L. Holt. Journ. M.B.A.
N.S. ii. 1891-92, p. 283.
Note on Scorpaena dactyloptera, de la Roche. By HE. W. L. Holt. Journ.
M.B.A. N.S. 1. 1893-95, p. 121.
19. THe GuRNAaRD Famity.
. Note on Trigla obscura, Linn. By EH. W. L. Holt. Journ. M.B.A. N.S. v.
1897-99, p. 197.
Malformation in Tub (Lrigla lucerna, Bloch.). By H. M. Kyle, p.se. Journ.
M.B.A. N.S. vi. 1900-03, p. 617.
20. Tue Sea Bream Famity.
Malformation of the Mouth in the Common Sea Bream. By Walter Gar-
stang, M.A. Journ. M.B.A. N.S. v. 1897-99, p. 345.
Ray’s Bream. By J.T. Cunningham, m.a. Journ. M.B.A. N.S.ii. 1891-92,
p. 78.
Note on Cantharus lineatus, Mont. By E. W. L. Holt. Journ. M.B.A.
N.S. v. 1897-99, p. 89.
21. Tue Perco Famity.
Polyprion cernum, Val. By W. L. Calderwood. Journ. M.B.A. N.S. ii.
1891-92, p. 396.
22. Rays AND SHARKS.
Notes on Raia alba (Lacép). By W. L. Calderwood. Journ. M.B.A. N.S. ii.
1891-92, p. 283.
The Blonde (Raia blanda, Holt and Calderwood, MS.), a species hitherto.
confounded with &. maculata, Montagu. (North Sea Investigations.)
By E. W. L. Holt. Journ. M.B.A. N.S. ii. 1893-95, p. 181.
On the Bottle-nosed Ray (Raza alba) and its Egg-purse. By HE. W. L. Holt.
Journ. M.B.A. N.S. v. 1897-99, p. 181. !
Note on Myliobatis aquila, Linn. The Hagle-ray. By E. W. L. Holt and
W. Garstang. Journ. M.B.A..N.S. v. 1897-99, p. -198.
Note on Trygon pastinaca, Linn. By E. W. L. Holt. Journ. M.B.A. N.S. v.
1897-99, p. 198.
Note on a Specimen of Echinorinus spinosus. By F. B. Stead, B.A. Journ.
M.B.A. N.S. iv. 1895-97, p. 264.
Notes on Centrina Salviani (with Plate XIII.). By W. L. Calderwood..
Journ. M.B.A. N.S. 1. 1891-92, p. 322.
Note on Chimaera monstrosa, Linn. By E. W. L. Holt. Journ. M.B.A.
N.S. ii. 1893-95, p. 120.
Echinorhinus spinosus, Blain. By H. M. Kyle, p.sc. Journ. M.B.A. N.S.
vi. 1900-03, p. 623.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. LONE
OYSTERS.
Oyster Culture in the River Yealm. By G. H. Fowler, B.a., pH.p. Journ.
M.B.A. N.S. ii. 1891-92, p. 78.
Notes on Oyster-culture. Pt.I. Oyster-farming in Holland. Pt. Il. Recent
Legislation relative to English Oyster Fisheries (with Plate XXI.). By
G. H. Fowler, B.A., pH.p. Journ. M.B.A. N.S. 1. 1889-90, p. 257.
The Generative Organs of the Oyster. Abstract of a paper by Dr. P. P. C.
Hoek (with Plates XXII. and XXIII.). Journ. M.B.A. N.S.i. 1889-
90, p. 268.
CRABS AND LOBSTERS.
On the Development of Palinurus vulgaris, the Rock Lobster or Sea-Crayfish
(with Plates VIII. and IX.). By J. T. Cunningham, m.a. Journ.
M.B.A. N.S. u. 1891-92, p. 141.
Recent Experiments relating to the Growth and Rearing of Food-fish at the
Laboratory. 1. The Rearing of Lobster Larve. By W. F. R. Weldon,
m.A., and G. H. Fowler, B.a., roH.p. Journ. M.B.A. N.S. 1. 1889-90,
p. 367.
The Lobster Fishing of one Boat in Plymouth District from May Ist to
September 29th, 1890.- By W. L. Calderwood. Journ. M.B.A. N.S. u.
1891-92, p. 15.
The Reproduction of the Lobster. By E. J. Allen, B.sc. Journ. M.B.A.
N.S. iv. 1895-97, p. 60.
Contributions to the Knowledge of the Natural History of the Lobster and
Crab. By J. T. Cunningham, m.a. Journ. Roy. Inst. Cornwall, vol.
xliv. - 1898.
Larval Lobsters at the Surface. By E. W. L. Holt. Journ. M.B.A. N.S. v.
1897-99, p. 196.
Young Lobsters. By W. L. Calderwood. Journ. M.B.A. N.S. 11. 1891-92,
p. 284.
On the Early Post-Larval Stages of the Crab (Cancer pagurus), and on the
affinity of that Species to Atelecyclus heterodon. By J.T. Cunningham,
M.A. Proceed. Zool. Soc. 1898, p. 204.
Notes on the Senses and Habits of some Crustacea, By W. Bateson, M.a.
Journ. M.B.A. N.S.1i. 1889-90, p. 211.
The Plague of Octopus on the South Coast, and its effect on the Crab and
Lobster Fisheries. By W. Garstang, M.a. Journ. M.B.A. N.S. vi.
1900, p. 260.
The Protection of Crabs and Lobsters. By E. J. Allen, B.sc. Journ. M.B.A.
N.S. iv. 1895-97, p. 182.
158 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
SPONGES.
Report on the Sponge Fishery of Florida and the Artificial Culture of Sponges.
By E. J. Allen, B.sc. Journ. M.B.A. N.S. iv. 1895-97, p. 188. Supple-
ment, p. 289.
Note on Projects for the Improvement of Sponge Fisheries. By G. Bidder.
Journ. M.B.A. N.S. iv. 1895-97, p. 195.
Morphological and Biological Publications.
FISHES.
Contractility of the Ivis in Fishes and Cephalopods. By W. Bateson, M.a.
Journ. M.B.A. N.S. 1. 1889-90, p. 215.
The “ Recessus Orbitalis,” an Accessory Visual Organ in Pleuronectid Fishes.
(North Sea Investigations.) By E. W. L. Holt. Journ. M.B.A. N.S. ii.
1893-95, p. 185.
The Palpebral and Oculomotor Apparatus in Fishes: observations on
Morphology and Development. By N. Bishop Harman, B.a., .B.
Journ. Anat. and Phys., vol. xxxiv. 1899.
The Air-Bladder and Ear of' British Clupeoid Fishes. By W. G. Ridewood.
Journ. Anat. and Phys., vol. xxvi.
Studies in Teleostean Morphology from the Marine Laboratory, Cleethorpes.
By HE. W. L. Holt. Proceed. Zool. Soc. 1894, p. 413.
Investigations on the Function of the Electrical Organ of the Skate (pre-
liminary note). By Prof. Burdon Sanderson, F.R.s., and F. Gotch, M.A.
Journ. M.B.A. N.S. 1. ~ 1889-90, p. 74.
The Head Kidney of Teleostean Fishes (with Plate I.). By W. L. Calder-
wood. Journ. M.B.A. N.S. ii. 1891-92, p. 43. alee
On the Coloration of the Skins of Fishes, especially Pleuronectide. By
J. T, Cunningham, m.a., and C. A. MacMunn, m.p. Phil. Trans. Roy.
Soc., vol. clxxxiv. B. 1898, p. 765.
Researches on the Coloration of the Skins of Flat Fishes. By J. T. Cunning-
ham, M.A. Journ. M.B.A. N.S. ii. 1893-95, p. 111. :
Additional Evidence on the Influence of Light in producing Pigments on the
Lower Side of Flat Fishes. By J. T. Cunningham, m.a. Journ. M.B.A.
N.S. iv. 1895-97, p. 53.
An Experiment concerning the Absence of Colour from the Lower Sides
of Flat Fishes. By J. T. Cunningham, m.a. Zoologischer Anzeiger.
1891, p. 27.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. Lae
On an Adult Specimen of the Common Sole with Symmetrical Eyes, with a
Discussion of its Bearing on Ambicoloration. (North Sea Investigations.)
By E. W. L. Holt. Journ. M.B.A. N.S. ii. 1893-95, p. 188.
An Observation of the Colour-changes of a Wrasse, Labrus maculatus, Dono-
van. By E. W. L. Holt and L. W. Byrne. Journ. M.B.A. N.S. v.
1897-99, p. 193.
Colour-changes in Cottus bubalis. By J.T. Cunningham, m.a. Journ. M.B.A.
N.S. i. 1889-90, p. 458.
On the Composition and Variations of the Pelvic Plexus in Acanthias vul-
garis. By R.C. Punnett, m.a. Proc. Roy. Soc. 68, p. 140, and 69, p. 2.
On the Anatomy of Centrophorus calceus (crepidalbus Bocage and Capello)
Giinther. By W. Woodland. Proceed. Zool. Soc., London, 1906, pp-
865-86.
On the Direction of the Aqueous Current in the Spiracle of the Dogfish ;
together with some Observations on the Respiratory Mechanism in
other Elasmobranch Fishes. By A. D. Darbishire. Linn. Soc. Journ.
Zool., vol. xxx. 1907, p. 86.
On some Experimental Tests of Recent Views concerning the Physiology
of Gas Production in Teleostean Fishes. By W. N. F. Woodland, D.sc.
Anat. Anzeiger, Bd. xl. 1911, p. 225. -
Notes on the Structure and Mode of Action of the “‘ Oval” in the Pollack
(Gadus pollachius) and Mullet (Muqil chelo). By W. N. F. Woodland,
p.sc. Journ. M.B.A. N.S. ix. 1910-13, p. 561.
The Influence of Light on the Coloration of Certain Marie Animals (Hippo-
lyte, Wrasses). By F. W. Gamble, p.sc., F.R.s. Trans. Manchester
Lit. and Phil. Soc. 1909.
The Relation between Light and Pigment formation in Crenilabrus and
Hippolyte. By Prof. F. W. Gamble, F.r.s. Quart. Journ. Micr. Sci.,
vol. lv. 1910, p. 541.
An Experimental Investigation on the Function of Reissner’s Fibre. By
G. E. Nicholls, B.sc. Journ. M.B.A. N.S.ix. 1910-13, p. 566.
An Experimental Investigation on the Function of Reissner’s Fibre. By
G. E. Nicholls, B.sc. Anat. Anzeiger, Bd. xl. 1912, p. 409.
The Structure and Development of Reissner’s Fibre and the Sub-commis-
sural Organ. Part 1. By George E. Nicholls, B.sc. Quart. Journ. Micr.
Sei., vol. lvii. 1912-13, p. 1.
On the Relations to Electrolytes of the Hearts of Different Species
of Animals. I. Elasmobranchs and Pecten. By G. R. Mines, .a.
Journ. Physiol., vol. xl. 1912, p. 467.
On Dynamic Equilibrium in the Heart. By G. R. Mines. Jouin. Physiol.,
vol. xlvi. 1913, p. 349.
A Peculiarly Abnormal Specimen of the Turbot. By J. T. Cunningham, m.a.
Journ. M.B.A. N.S. vill. 1907-10, p. 44.
160 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
Note on a Hermaphrodite Cod (Gadus morrhua). By A. E. Hefford, B.sc.
Journ. M.B.A. N.S. vin. 1907-10, p. 315.
Note on a Conger with Abnormal Gonad. By A. E. Hefford, B.sc. Journ.
M.B.A. N.S. vui. 1907-10, p. 318.
PROTOCHORDATA.
Preliminary note on a new theory of the Phylogeny of the Chordata. By
W. Garstang, M.A. Zoolog. Anzeiger. 1894, p. 122.
Report on the Tunicata of Plymouth (with Plate I.). By W. Garstang, M.a.
Journ. M.B.A. N.S. 1. 1891-92, p. 47.
‘On some Ascidians from the Isle of Wight, a Study in Variation and Nomen-
clature (with Plates VI. and VII.). By W. Garstang, m.a. Journ.
MBA) N-S. ©1891-9325 p19:
Note on a New and Primitive Type of Compound Ascidian. By W. Gar-
stang, M.A. Ann. and Mag. Nat. Hist. 1891.
Observations on Ascidians (Report on the Occupation of Table). By Arthur
Willey, B.sc. Rep. Brit. Assoc. 1892.
The Development of Stigmata in Ascidians. By W. Garstang, M.a. Proceed.
Roy. Soc., vol. li. 1892, p. 505. ‘
Note on Salensky’s account of the development of the Stigmata in Pyrosoma.
By W. Garstang, M.A. Trans. Liverpool Biol. Soc., vol. vii. 1892-93,
p. 245.
Outlines of a new Classification of the Tunicata. By W. Garstang, M.A.
Rep. Brit. Assoc., Ipswich. 1895, p. 718.
Budding in Tunicata. By W. Garstang, M.A. Science Progress, vol. i. 1895.
Studies on the Protochordata. By Arthur Willey, B.sc. Quart. Journ. Micr.
Sci., vol. xxxiv. 1893, p. 317.
On a new Genus of Synascidian from Japan. By Asajiro Oka, of the Imperial
University of Tokio, and Arthur Willey, B.sc. Quart. Journ. Micr.
Sel. vol aoodn 8923p. a1.
Phoronis at Plymouth. By W. Garstang, m.a. Journ. M.B.A. N.S. u.
1891-92, p. 77.
On a Tornaria found in British Seas (with Plates VII. and VIII). By
G. C. Bourne, m.a. Journ. M.B.A. N.S.1. 1889-90, p. 63.
MOLLUSCS.
On the Gastric Gland of Mollusca and Decapod Crustacea ; its Structure and
Functions. By C. A. MacMunn, M.a., M.D. Proceed. Roy. Soc., vol. lxiv.
1899, p. 436.
Notes on the Minute Structure of the Nervous System of the Mollusca. By
J. Gilchrist, M.a., PH.D. Journ. Linn. Soc., vol. xxvi. 1897, p. 179.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 161
The Mollusca collected by the Hualey from the North Side of the Bay of
Biscay in August, 1906. By Alexander Heyned Journ. M.B.A. N.S.
vill. 1907-10, p. 359.
On the Aplacophorous Amphineura of British Seas. By W. Garstang, M.A.
Proceed. Malacol. Soc., vol. ii. Oct., 1896, p. 123.
Sound heard by a Lamellibranch (Anomia). By W. SUG, M.A. Journ.
M.B.A. N.S. i. 1889-90, p. 217.
Some Points in the Physiology of Lamellibranch Blood-Corpuscles. By
G. H. Drew, B.A. Quart. Journ. Micr. Sci., vol. liv. 1910, p. 605.
The Origin and Formation of Fibrous Tissue produced as a Reaction to
Injury in Pecten mawimus, as a Type of the Lamellibranchiata. By
G. H. Drew, B.a., and W. De Morgan: Quart. Journ. Micr. Sci., vol. lv.
1910, p. 595.
Experimental Metaplasia. I. The Formation of Columnar Ciliated Epi-
thelium from Fibroblasts in Pecten. By G. H. Drew, B.a. Journ.
Exper. Zool., vol. x. 1911, p. 349. <
Anatomy of British Species of Psammobia. By H. H. Bloomer. Proc.
Malac. Soc., vol. ix. 1911, p. 231 ; v5
Notes on the Development of Mytilus edulis and Alcyonium digitatum in the
Plymouth Laboratory. By Annie Matthews, m.sc. Journ. M.B.A.
N.S: ix. 1910-13, p. 557
On the Gastropod Colpodaspis pusilla of Michael Sars. By W. Garstang, M.A.
Proceed. Zool. Soc. 1894, p. 664.
On the Anatomy of Trochus. By W. B. Randles. Report Brit. Assoc.
Glasgow. 1901, p. 377.
Some Observations on the Anatomy and Affinities of the Trochide. By
W. B. Randles, B.sc. Quart. Journ. Micr. Sci. xlvin. 1904, p. 33.
An Account of the Natural History of the Slipper-Limpet (Crepidula forni-
cata), with some remarks on its occurrence on the Oyster Grounds on
the Essex Coast. By J. H. Orton, B.sc. Journ. M.B.A. N.S.ix. 1910-
13, p. 437. as
The Mode of Feeding of Crepidula, with an account of the current-producing
mechanism in the mantle cavity, and some remarks on the Mode of
Feeding in Gastropods and Lamellibranchs. By J. H. Orton, B.sc.
Journ. M.B.A. N.S. ix. 1910-13, p. 444.
British Nudibranchiate Mollusca. Supplement. By C. Eliot. Ray Society,
1910.
A complete list of the Opisthobranchiate Mollusca found at Plymouth, with
further Observations on their Morphology, Colours, and Natural History
(with Plates XXVII., XXVIII.). By W. Garstang, M.a. Journ. M.B.A.
N.S. i. 1889-90, p. 399. |
Report on the Nudibranchiate Mollusca of Plymouth Sound. By W. Gar-
stang, M.A. Journ. M.B.A. N.S8.1., p. 173.
NEW SERIES.—VOL. X. NO. 1. NOVEMBER, 1913. L
162 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
Nudibranchiata collected in the North Sea by the s.s. Huzley during July
and August, 1907. By C. L. Walton. Journ. M.B.A. N.S. viii. 1907-10,
p. 227.
On the Occurrence of the Nudibranch Hancockia at Plymouth. By F. W.
Gamble, B.sc. Journ. M.B.A. N.S. 1. 1891-92, p. 193.
Pleurophyllidia Lovéni, Bergh. By J.T. Cunningham, m.a. Journ. M.B.A.
N.S. ii. 1891-92, p. 194.
On the Structure and Habits of Jorunna Johnston. By W. Garstang, M.A.
Conchologist, vol. 1. 1893, p. 1.
On the Relations of Hesse’s Doto wncinata to the Genus Hancockia. By
W. Garstang, M.A. Conchologist, vol. ii. 1893, p. 110.
On Doris maculata, a new species of Nudibranchiate Mollusk found at Ply-
mouth. By W. Garstang, m.a. Journ. M.B.A. N.S. iv. 1895-97.
p. £67:
Coryphella smaragdina. By J.C.Sumner. Journ. M.B.A. N.S.ui. 1893-95,
p- 236. ay
Cuthona ? aurantiaca. By J.C. Sumner. Journ. M.B.A. N.S. iv. 1895-
97, p. 75.
Notes on some British Nudibranchs. By C. Ehot. Journ. M.B.A. NS. vii.
1904—06, p. 333.
On the Nematocysts of Aolids. By G. H. Grosvenor, B.A. Proceed. Roy.
Noes, aan, 1903; pp. 462:
On the Doris Planata of Alder and Hancock. By Sir C. N. E. Eliot. Proceed.
Malacol. Soc., vol. vi. 1904, p. 180.
Notes on Two Rare British Nudibranchs, Hero Formosa, var. Arborescens, and
Staurodoris maculata. By Sw C. N. E. Ehot. Proceed. Malacol. Soc.,
vole. )1905,"p..239. ~~
The Pigments of Aplysia punctata. By C. A. MacMunn, u.a., Mp. Journ.
Physiol., vol. xxivé 1899, p. 1. ‘
On the Genus Cumanotus. By C. Ehot. Journ. M.B.A. N.S. vii. 1907-10,
p. 313.
Some Notes on the Genus Cumanotus. By Nils Odhner. Journ. M.B.A.
N.S. ix. 1910-13, p. 82.
Note on a British Cephalopod (Illex eblanae, Ball). By W. E. Hoyle, m.a.
Journ. M.B.A. N.S. ii. 1891-92, p. 189.
Note on a Large Squid (Ommastrephus pteropus, Stp.). By E. 8. Goodrich.
Journ. M.B.A. N.S. ii. 1891-92, p. 314.
Specialized Organs seen in Action (Tentacles of Sepia). By J. T. Cunning-
ham, M.a. Journ. M.B.A. N.S. iii. 1893-95, p. 166.
Note on Sepia elegans, d’ Orb. By E. W. L. Holt and W. I. Beaumont.
Journ. M.B.A. N.S. v. 1897-99, p. 343.
Eledone. By A. Isgrove, m.sc. L.M.B.C. Memoirs, xviii. 1909.
The Brachiopoda collected by the Hualey from the North Side of the Bay
of Biscay, in August, 1906. By Alexander Reynell. Journ. M.B.A.
N.S. viii, 1907-10, p. 392.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 163
POLYZOA.
On the Regeneration of Lost Parts in the Polyzoa. By S. F. Harmer, m.a.
Rep. Brit. Assoc. 1890.
On the British Species of Crisia. By S. F. Harmer, m.a. Quart. Journ.
Micr. Sci., vol. xxxii. 1891, p. 127.
On the Occurrence of Embryonic Fission in Cyclostomatous Polyzoa. By
Sele Harmer, M.A. Quart. Journ. Micr. Sci., vol. xxxiv. 1893, p 1o9%
Note on New or Rare British Marine Polyzoa. By 8S. F. Harmer, m.a. Journ.
MBSA] N:S vy. > 1897-99) p.. 51.
On the Development of Tubulipora, and on some British and Northern
Species of this Genus. By S. F. Harmer, m.a. Quart. Journ. Micr. Sci.,
vol. xli., p. 73.
The Embryology of the Polyzoa. By T. H. Taylor, m.a. Report Brit. Assoc.
1899.
On the Early Stages in the Development of Flustrella hispida (Fabricius),
and on the Existence of a “ Yolk Nucleus” in the Egg of this Form.
By R. M. Pace. Quart. Journ. Micr. Sci., vol. 1. 1906, p. 435.
On a Method of Rearing Larve of Polyzoa. By Dr. M. Hasper. Journ.
M.B.A. N.S. ix. 1910-13, p. 435.
CRUSTACEA.
On some Rare and Interesting Crustacea from the Dogger Bank collected by
K. W. L. Holt, Esq. By Thomas Scott, r.u.s. Ann. and Mag. Nat. Hist.
(6) xiii. 1894, p. 412.
The Crustacea of Devon and Cornwall. By A. M Norman, r.r.s., and
T. Scott, tu.p. London, 1906, p. 1. 4
The Decapoda collected by the Hualey from the North Side of the Bay of
Biscay in August, 1906. By Stanley Kemp, B.a. Journ. M.B.A. N.S.
villi. 1907-10, p. 407.
Note on the Function of the Spines of the Crustacean Zocea (with Plate XVI.)
By W. F. R. Weldon, m.a. Journ. M.B.A. N.S. i. 1889-90, p. 169.
The Habits and Respiratory Mechanism of Corystes cassivelaunus. (Con-
tributions to Marine Bionomics, I.) By W. Garstang, m.a. Journ.
M.B.A. N.S. iv. 1895-97, p. 223.
The Functions of Antero-Lateral Denticulations of the Carapace in Sand-
burrowing Crabs. (Contributions to Marine Bionomics, II.) By W.
Garstang, M.A. Journ. M.B.A. N.S. iv. 1895-97, p. 396.
The Systematic Features, Habits, and Respiratory Phenomena of Portumnus
nasutus (Latreille). Contributions to Marine Bionomics, III.) By W.
Garstang, M.A. Journ. M.B.A. N.S. iv. 1895-97, p. 402.
164 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES,
On some modifications of Structure subservient to Respiration in Decapod
Crustacea which burrow in Sand. By W. Garstang, M.A. Quart. Journ.
Miers Scis/vel) xl p72 ule
On the Function of certain Diagnostic Characters of Decapod Crustacea. By
W. Garstang, M.A. Rep. Brit. Assoc., Liverpool, 1895, p. 828.
On the Habits of Pinnotheres pisum. By A. D. Darbishire. Report Brit.
Assoc. Bradford. 1900, p. 399.
On the Species Upogebia stellata and Gebia deltura. By W. De Morgan.
Journ. M.B.A. N.S. viii. 1907-10, p. 475.
Some Points in the Histology of the Nervous System of the Embryonic
Lobster. By E. J. Allen, B.sc. Proceed. Roy. Soc., vol. lv. 1894, p. 407.
Studies on the Nervous System of Crustacea. By E. J. Allen, B.sc. I. Some
Nerve-elements of the Embryonic Lobster. II. The Stomatogastric
System of Astacus and Homarus. III. On the Beading of Nerve-fibres
and on End-swellings. Quart. Journ. Micr. Sci., vol. xxxvi. 1894, p. 461.
IV. Further Observations on the Nerve-elements of the Embryonic
Lobster. Quart. Journ. Micr. Sci., vol. xxxix. 1896, p. 35.
Nerve-elements of the Embryonic Lobster. By E. J. Allen, B.sc. Journ.
M.B.A. N.S. i. 1893-95, p. 208.
Additional Observations on the Nerve-elements of the Embryonic Lobster.
By E. J. Allen, B.sc. Journ. M.B.A. N.S. iv. 1895-97, p. 70.
Das Nervensystem von Carcinus maenas, 1.,1., and 11. Von A. Bethe, PH.D.
Archiv fiir Mikros. Anat., 1., 1897, pp. 460 and 589 ; and li., 1898, p. 383.
The Formation of the Germ Layers in Crangon vulgaris. By Professor
Weldon, F.R.Ss. Quart. Journ. Micr. Sci., vol. xxx. 1892, p. 343.
The Coelom and Nephridia of Palaemon serratus (with Plates XIII. to XV.).
By W. F. R. Weldon, M.a. Journ. M.B.A. N.S. 1. 1889-90, p. 162.
The Renal Organs of Certain Decapod Crustacea. By Professor Weldon,
F.R.S. Quart. Journ. Micr. Sci., vol. xxxu. 1891, p. 279.
The Colour-physiology of Higher Crustacea. By F. Keeble, p.sc., and F. W.
Gamble, p.sc. Phil. Trans. Roy. Soc. Ser. B, vol. 196. 1904, p. 295.
Types of Crustacean Blood Coagulation. By John Tait, M.p., p.sc. Journ.
M.B.A. N.S. ix. 1910-13, p. 191.
On the Nauplius Eye persisting in some Decapoda. By M. Robinson. Quart.
Journ. Micr. Sci., vol. xxxin. 1892, p. 283.
The Minute Structure of the Gills of Palaemonetes varians. By E. J. Allen,
B.sc. Quart. Journ. Micr. Sci., vol. xxxiv. 1892, p. 75.
Preliminary Account of the Nephridia and Body-cavity of the Larva of
Palaemonetes varians. By HE. J. Allen, B.sc. Proceed. Roy. Sci., vol. 1u.
1892, p. 338.
The Nephridia and Body-cavity of some Decapod Crustacea. By E. J.
Allen, B.sc. Quart. Journ. Micr. 8ci., vol. xxxiv. 1892-93, p. 403.
A Carcinus with a Right-handed Walking-leg on the Left Side of the Abdo-
men. By A. Bethe, po.p. Journ. M.B.A. N.S. iv. 1895-97, p. 144.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 165
Ein Carcinus maenas (Taschenbrebs) mit einem rechten Schreitbein an der
linken Seite des Abdomens. Ein Beitrag zur Vererbungstheorie. By
A. Bethe, p#.p. Arch. Entwick. mech. iii. 1896, p. 301.
Metamorphoses of the Decapod Crustaceans Aegeon (Crangon) fasciatus,
Risso, and Aegeon (Crangon) trispinosus (Hailstone). By Robert Gurney,
B.A., F.L.S. Proceed. Zool. Soc. London. 1903, 11. p. 24.
The Larve of Certain British Crangonide. By R. Gurney, B.a. Journ.
M.B.A. N.S. vi. 1903, p. 595. ii
Palaemonetes varians in Plymouth. By W. F. R. Weldon, m.a. Journ.
M.B.A. N.S.1i. 1889-90, p. 459.
The Metamorphosis of Corystes cassivelaunus (Pennant). By R. Gurney, B.A.
Quart. Journ. Micr. Sci., xlvi. p. 461.
Studies in the Experimental Analysis of Sex. VII. Sexual Changes in the
Blood and Liver of Carcinus maenas. By Geoffrey Smith, M.a. -Quart.
Journ. Micr. Sci., vol. Ivii. 1911, p. 251. ?
Studies in the Experimental Analysis of Sex. Part 10. The Effect of Saccu-
lina on the Storage of Fat and Glycogen, and on the Formation of
Pigment by its Host. By Geoffrey Smith, m.a. Quart. Journ. Micr.
peta. vols lrx. ) 19135 ps 267:
The fixation of the Cypris Larva of Sacculina carcini (Thompson) upon its
Host, Carcinus maenas. By Geoffrey Smith, M.A. Quart. Journ. Micr.
Sci., vol. li. 1907, p. 625.
Hermit Crabs and Anemones. By G. H. Fowler, p#.p. Journ. M.B.A. N.S. i.
1891-92, p. 75.
On the Development of Nebalia. By Margaret Robinson. Quart. Journ.
Mier. Sci., vol. 50. 1906, p. 383.
Notes on Mysis longicornis, Milne-Edwards, and Mysidopsis angusta, G. O.
Sars. By EH. W. L. Holt and W. I. Beaumont, B.a. Journ. M.B.A.
N:S.iv- 1897—99).p> 314.
On Siriella armata (M.-Edw.) and the reputed occurrence of S. frontalis
(M.-Edw.) in British Seas. By E. W. L. Holt and W. I. Beaumont, B.a.
Ann. and Mag. Nat. Hist. (7), ii., 1899, p. 151.
Notes on some Amphipoda from the North Side of the Bay of Biscay. Families
Pleustidae and Eusinidae. By E. W. Sexton. Proc. Zool. Soc., 1909,
p. 848.
The Amphipoda collected by the Hualey from the North Side of the Bay of
Biscay in August, 1906. By E. W. Sexton. Journ. M.B.A. NS. ix.
1910-13, p. 199.
On the Amphipod Genus Trischizostoma. By E. W. Sexton. Proc. Zool.
Soc., 1908, p. 370.
A new Amphipod Species, T'ryphosites allent. By E. W. Sexton. Ann. and
Mag. Nat. Hist., ser. 8, vol. vu. 1911, p. 510.
On the Amphipod Genus Leptocheirus. By E. W. Sexton. Proc. Zool.
Soc., 1911, p. 561.
166 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
The Schizopoda and Isopoda collected by the Hualey from the North Side
of the Bay of Biscay, in August, 1906. By W. M. pe hp eda M.SC.
Journ. M.B.A. N.S. vin. 1907-10, p. 189.
Some Brackish-water Amphipoda from the mouths of the Weser and the
Elbe, and from the Baltic. By E. W. Sexton. Proc. Zool. Soc. Lond.
1912, p. 656.
Description of a New Species of Brackish-water Gammarus (G. chevreuxt
n. sp.). By EH. W. Sexton. Journ. M.B.A. N.S. ix. 1910-13, p. 542.
Notes on the Life History of Gammarus chevreuxi. By E. W. Sexton and
Annie Matthews. Journ. M.B.A. N.S.ix. 1910-13, p. 546.
Notes on the Genus Monstrilla, Dana. By G. C. Bourne, M.a. Quart. Journ.
Micr. Sci., vol. xxx. 1890, p. 565. te
Monstrilla Helgolandica, Claus, at Plymouth. By R. Gurney, B.a. Journ.
M.B.A. N.S. vi. 1903, p. 627. ah
On the Early Development of Cirrhipedia. By T. T. Groom, m.a. Proceed.
Roy. Soc., vol. li. 1892, p. 158.
The Distribution of Unciola crenatipalmata, Bate. By W. Garstang, M.a.
Journ. M.B.A. N.S. i. 1893-95, p. 119.
Report on the Pelagic Copepoda collected at Plymouth in 1888- 89 (with
Plates XI. and XII.). By G. C. Bourne, m.a. Journ. M.B.A. N.S. i.
1889-90, p. 144.
- The Movements of Copepoda. By Prof. E. W. MacBride, m.a. Quart. Journ.
Micr. Sci., vol. xl. 1899, p. 505.
A list of the Parasitic Copepoda of Fish obtained at Plymouth. By P. W.
Bassett-Smith. Journ. M.B.A. N.S.iv. 1895-97, p. 155.
Notes on the Parasitic Copepoda of Fish obtained at Plymouth, with descrip-
tions of New Species. By P. W. Bassett-Smith. Ann. and Mag. Nat.
Hist. (6), vol. xviii. 1896, p. 8.
Sur un Copépode nouveau parasite de Polycirrus aurantiacus, Grube. KE,
Brumpt. Comptes rendus. June 21, 1897.
Pycnogonida. By T. V. Hodgson. National Antarctic Expedition. Natural
History, vol. 1. 1907.
The Pycnogonida of the Scottish National Antarctic Expedition. By T. V.
Hodgson. Trans. Roy. Soc. Edin., vol. xlvi. 1908, p. 159.
The Pycnogonida of Devonshire. By T. V. Hodgson. Trans. Devonshire
Assoc., vol. xl. 1910, p. 425.
ANNELIDS.
The Incubation of the Skate-leech, Pontobdella muricata, Linn. By EH. W. L.
Holt. Journ. M.B.A. N.S. v. 1897-99, p. 195.
Notes on Pontobdella muricata. By the Hon. Henry Gibbs. Journ. M.B.A.
N.S. v.. 1897-99, p. 330.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 167
Contributions to the Anatomy and Histology of Thalassema neptuni, Gaertner.
By H. L. Jameson. Jena Fischer. 1899.
Notes on the Marine Oligochaeta of Plymouth. By F. E. Beddard,
Journ. M.B.A. N.S.i. 1889-93, p. 69.
Certain Points in the Structure of Clitellio. By F. E. Beddard, .a. Proceed.
Zool. Soc. 1888, p. 485.
On Some British Species of Pachydrilus. By F. E. Beddard, m.a. Proceed.
Roy. Phys. Soc. Edinburgh. 1889.
The Nephridium of Lumbricus, with Remarks on the Nephridia of other
Chaetopods. By W. B. Benham, D.sc. Quart. Journ. Mier. Sci., vol.
xxx. 1891, p. 293.
The Amphinomidae, Aphroditidae, Polynoidae, and Sigalionidae of Plymouth
and the English Channel. By T. V. Hodgson. Journ. M.B.A. N.S. vi.
1900, p. 218.
On the Nephridia of the Polychaeta, 11. By E. 8. Goodrich. Quart. Journ.
Micr. Sci., xl. 1900, p. 699.
List of Polychaets taken at Plymouth. (Report on the Occupation of Table.)
By Florence Buchanan, B.sc. Rep. Brit. Assoc. 1892.
The Anatomy and Classification of the Arenicolidae, with some observations
on their post-larval stages. By F. W. Gamble and J. H. Ashworth.
Quart. Journ. Micr. Sci., xl. 1900, p. 419.
Report on Nerves of Arenicola, Nereis, etc. By F. W. Gamble, m.sc. Report
Brit. Assoc. 1898, p. 584.
The Post-larval Stage of Arenicola marina. By W.B. Benham, p.sc. Journ.
M.B.A. .NiS. m1. 1893-95, p. 48:
The Connections of the Gonadial Blood Vessels aaalt the Form of the N ephridia
in the Arenicolidae. By E. R. Downing. Biol. Bull., vol. xvi. 1909,
p. 246.
Note on the Early Larvae of Nephthys and Glycera. By H.M. Fuchs. Journ.
M.B.A. N.S. ix. 1910-13, p. 164.
On a Blood-forming Organ in the Larva of Magelona. By Florence Buchanan,
B.sc. Report Brit. Assoc. 1895, p. 469.
Pallasia murata, n. sp.: A New British Sabellarian. By EH. J. Allen, p.sc.
Journ, M.B.A. N.S. vu. 1904-06, p. 299.
Observations on the Habits of the Onuphidae. By A. T. Watson. Trans.
Liverpool Biol. Soc., vol. xvi. 1903, p. 503. .
The Anatomy of Poecilochaetus. By E. J. Allen, p.sc. Quart. Journ. Micr.
Sci., vol. xlvii. 1904, p. 79.
On the Anatomy of Histriobdella homari. By C. Shearer, M.A. Quart. Journ.
Micr. Sci., vol. lv. 1910, p. 287.
Notes on the Anatomy of Dinophilus (with Plates IX. and X.). By 5. F.
Harmer, M.A. Journ. M.B.A. N.S. i. 1889-90, p. 119.
On the Structure of the Nephridia of Dinophilus. By Cresswell Shearer.
Quart. Journ. Micr. Sci., vol. 1. 1906, p. 517.
168 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
The Problem of Sex Determination in Dinophilus gyrociliatus. By Cresswell
Shearer, M.A. Journ. M.B.A: N.S. ix. 1910-18, p. 156.
The Problem of Sex Determination in Dinophilus gyrociliatus. Pt. 1. The
Sexual Cycle. By Cresswell Shearer, m.a. Quart. Journ. Micr. Sci.,
vol: Ivar WO125sp329-
NEMERTINES, TURBELLARIA, etc.
A list of the Nemertines of Plymouth Sound. By T. H. Riches, B.a. Journ.
M.B.A.” NS. 1. 1893-95, p. 1.
List of Nemerteans collected in the Neighbourhood of Plymouth from
May-September, 1910. By Dr. Gerarda Wijnhoff. Journ. M.B.A.
N.S. ix. 1910-13, p. 407.
Die Systematik der Nemertinen. By Dr. G. Wijnhoff. Zool. Anzeiger,
Bd. xls 1912, p.337.
A New British Nemertine. By T. H. Riches, B.a. Journ. M.B.A. N.S. ii.
1891-92, p. 284.
Description of a New Species of Nemertine. By J. C. Sumner. Ann. and
Mag. Nat. Hist. (6), vol. xiv. 1894.
On Two New British Nemerteans. By R. C. Punnett, m.a. Quart. Journ.
Mier. Sci. xhiv9 19015 sp. 547:
Die Gattung Cephalothrix und ihre Bedeutung fiir die Systematik der
Nemertinen. IJ. Systematischer Teil. By Dr. Gerarda Wijnhoff.
Zool. Jahrb., Bd. xxxiv. 1913, p. 291.
Contributions to a Knowledge of British Marine Turbellaria. By F. W.
Gamble, B.sc. Quart. Journ. Micr. Sci., vol. xxxiv. 1892-93, p. 433.
The Turbellaria of Plymouth Sound and the Neighbourhood. By F. W.
Gamble, B.sc. Journ. M.B.A. N.S. ili. 1893-95, p. 30.
A Review of the British Marine Cercariae. By M. V. Lebour, m.sc. Para-
sitology, vol. iv. 1912, p. 416.
On Two New Trematode Parasites from British Food-Fishes. By W. Nicoll,
M.A., D.Sc., M.D. Parasitology, vol. v. 1912, p. 197.
New Trematode Parasites from Fishes of the English Channel. By William
Nicoll, M.a., D.Sc., M.D. Parasitology, vol. v. 1918, p. 238.
ECHINODERMS.
Notes on the Echinoderms collected by Mr. Bourne in Deep Water off the
South-west of Ireland in H.M.S. Research. By F. Jeffrey Bell, .a.
Journ. M.B.A. N.S. i. 1889-90, p. 324.
The Echinoderms collected by the Hualey from the North Side of the Bay
of Biscay in August, 1906. By W. De oe Journ. M.B.A. N.S. ix.
1910-13, p. 530.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 169
On the Echinoderm Fauna of Plymouth. By J. C. Sumner. Report Brit.
Assoc. 1895, p. 471.
The Organogeny of Asterina gibbosa. By E. W. MacBride, m.a. Proceed.
Roy. Soc., vol. liv. 1893, p. 431.
The Development of Asterina gibbosa. By E. W. MacBride, M.a. Quart.
Journ. Micr. Sci., vol. xxxvin. 1895-96, p. 339.
Report on the Work done during the Occupation of the British Association
Table at Plymouth, June, 1905. (Development of Ophiothrix fragilis.)
By E. W. MacBride, ¥.r.s. Report Brit. Assoc. South Africa, 1905,
p- 183.
The Development of Ophiothrix fragilis. By Prof. E. W. MacBride, D.sc.,
F.R.S. Quart. Journ. Micr. Sci., vol. li. 1907, p. 557.
Some Points in the Development of Ophiothrix fragilis. By Prof. E. W.
MacBride, D.sc., F.R.S. Proc. Roy. Soc., Ser. B., vol. Ixxix. 1907, p. 440.
The Growth of the Oocyte in Antedon: a Morphological Study in Cell-
Metabolism. By G. C. Chubb, p.sc. Proceed. Roy. Soc. B. 519. 1906,
p- 384. See also Phil. Trans. Roy. Soc. Ser. B., vol. 198. 1906, p. 447.
On some Bipinnariae from the English Channel. By W. Garstang, M.A.
Quart. Journ. Micr. Sci., vol. xxxv. 1894, p. 451.
The Development of Echinoids. Part 1. The Larvee of Echinus miliaris and
Echinus esculentus. By Prof. E. W. MacBride, m.a. Quart. Journ. Micr.
Sci., vol. xlu. 1899, p. 335.
The Development of Echinus esculentus. By E. W. MacBride. Proc. Roy.
Soc., 68, p. 268. Also Phil. Trans. Roy. Soc., 1903, p. 285.
The Rearing of Larve of Echinidae. By Prof. E. W. MacBride, M.a. Report
Brit. Assoc., 1899.
Notes on the Rearing of Echinoid Larve. By Prof. E. W. MacBride, M.a.
Journ. M.B.A., vol. vi. 1900, p. 94.
Preliminary Notice on the Experimental Hybridization of Echinoids. By
Cresswell Shearer, Walter De Morgan, and H. M. Fuchs, Journ. M.B.A.
Nese rx, I9IO=15) py 121.
On Paternal Characters in Echinoid Hybrids. By C. Shearer, W. De Morgan,
and H. M. Fuchs. Quart. Journ. Micr. Sci., vol. vii. 1912, p. 337.
On Echinoderm Hybridization. By H. M. Fuchs. Rept. Brit. Assoc. Adv.
Sci. 1912, p. 494.
On Methods of raising Parthenogenetic Larvae of Hchinus esculentus. By
Dorothy Jordan Lloyd, B.sc. Brit. Assoc. Rept. 1912, p. 495.
Cytological Observations on the Early Stages of Segmentation of Echinus
Hybrids. By L. Doncaster, m.a., and J. Gray, B.A. Quart. Journ.
Micr. Sci., lvi. 1912-13, p. 483.
On Methods of Producing Artificial Parthenogenesis in Echinus esculentus
and the Rearing of the Parthenogenetic plutei through Metamorphosis.
By Cresswell Shearer and Dorothy Jordan Lloyd. Quart. Journ. Micr.
Sci., vol. lvii. 1912-13, p. 523.
L2
170 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES,
The Effects of Hypertonic Solutions upon the Eggs of Echinus. By J. Gray.
Proc. Camb. Phil. Soc., vol. xvu. 1918.
The Effects of Hypertonic Solutions upon the Fertilized Eggs of Echinus
(E. esculentus and FE. acutus). By J. Gray, B.A. Quart. Journ. Micr.
Sci., vol. lvin. 1912-13, p. 447.
The Inheritance of the Aboral Process of the Echinocardium Pluteus. By
H. M. Fuchs. Arch. f. Entwick. d. Organismen, Bd. xxxv. 1912-13,
p- 558.
On some Parasites found in Echinus esculentus, L. By A. E. Shipley. Quart.
Journ. Micr. Sci., xliv. 1901, p. 281.
Notiz iiber die Excretion der Holothurien. By P. Barthels, pH.p. Zool.
Anzeiger. 1895, p. 493. :
Note on the Mechanism of Discharge of the Cuvierian Organs of Holothuria
migra. By G. R. Mines, mM.a. Quart. Journ. Micr. Sci., vol. lvu. 1912,
p- 301.
On Cucumaria Montagui, Fleming. By A. M. Norman, r.r.s. Ann. Mag.
Nat. Hist. Ser. 7, vol. xvi. 1905, p. 352.
Note on Two Species of Cucumaria from Plymouth, hitherto confused as
C. Montagui (Fleming): C. Normani, n. sp., and C. saxicola (Brady and
Robertson). By 8. Pace. Journ. M.B.A. N.S. vu. 1904-06, p. 305.
COELENTERATES.
Beitrige zur Kenntnis der Spermatogenese bei den Célenteraten. By W. M.
Aders, PH.D. Zeitsch. Wiss. Zool., vol. 74. 1893, p. 81.
Tealia tuberculata, Cocks: a Study in Synonymy (with Plate XIX.). By
J.T. Cunningham, m.a. Journ. M.B.A. N.S. 1. p. 205.
On Phellia murocincta (Gosse). By C. L. Walton. Journ. M.B.A. N.S. vii.
1907-10, p. 47.
Notes on some Sagartidae and Zoanthidae from Plymouth. By C. L. Walton.
Journ. M.B.A. N.S. vii. 1907-10, p. 207.
Actimiae collected by the s.s. Hurley in the North Sea during the Summer
of 1907. By C. L. Walton. Journ. M.B.A. N.S. vin. 1907-10,
p- 215.
Kodioides borleyi, n. sp. By C. L. Walton. Journ. M.B.A. N.S. ix. 1910-
13, p. 85.
On some Colour Variations and Adaptations in Actiniae. By C. L. Walton.
Journ. M.B.A. N.S. ix. 1910-13, p. 228.
Notes on various British Anthozoa. By C. L. Walton. Journ. M.B.A. N.S.
ix. 1910-13, p. 236.
The Alcyonaria, Antipatharia, and Madreporaria collected by the Hualey
from the North Side of the Bay of Biscay in August, 1906. By Prof.
S. J. Hickson, M.a., F.R.S. Journ. M.B.A. N.S. viii. 1907-10, p. 6.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. bral
Some preliminary Notes on the Anatomy and Habits of Alcyontwm digitatum.
By 8S. J. Hickson, m.a. Rep. Brit. Assoc. 1892.
The Anatomy of Alceyonium digitatum. By Prof. 8. J. Hickson, ¥.r.s, Quart.
Journ. Micr. Sci., vol. xxxvil. 1894-95, p. 343.
Report on Mr. J. H. Wandsworth’s collection of material for the Study of the
Embryology of Aleyonium. By Prof. 8. J. Hickson, F.r.s. Report
Brit. Assoc. 1898, p. 585. \
Notes on the Maturation of the Ovum of Alcyoniwm digitatum. By M. D.
Hill, m.a. Quart. Journ. Micr. Sci., vol. xiv. 1905, p. 493.
Virgularia mirabilis. By W. P. Marshall. Journ. M.B.A. N.S.i. 1893-95,
p. 335.
Notes on the Hydroids of Plymouth (with Plate XXVI.). By G.C. Bourne,
M.A. Journ. M.B.A. N.S.1i. 1889-90, p. 321.
The Hydroids collected by the Hualey from the North Side of the Bay of
Biscay in August, 1906. By E. T. Browne. Journ. M.B.A. N.S. viii.
1907-10, p. 15.
Tektonische Studien an Pearse: Von Hans Driesch. Jenaische
Zeitschrift. Vols. xxiv. and xxv.
On some Points in the Histology and Development of Myriothela phrygia. By
W. B. Hardy, B.A. Quart. Journ. Micr. Sci., vol. xxxn. 1891, p. 505.
Notes on Plymouth Hydroids. By Prof. C. C. Nutting. Journ. M.B.A.
N.S. iv. 1895-97, p. 146.
Notes on the Reproduction of Plumularian Hy roids: By Prof. C. C. Nutting.
American Naturalist, Nov., 1895, p- 966.
Notes on Plymouth Hydroids. By Prof. C. C. Nutting. Bull. Lab. Nat.
Hist. Iowa. Vol. iv., No. 1, p. 1.
On Three New Species of Hydroids and one new to Britain. By Prof. C. C.
Nutting. Ann. and Mag. Nat. Hist. (7) 1. 1898, p. 362.
On Tubularia crocea in Plymouth Sound. By E. T. Browne, B.a. Journ.
M.B.A. N.S. v. 1897-99, p. 54.
On the Occurrence of a Northern Hydroid, Halatractus (Corymorpha) nanus
(Alder), at Plymouth. By Dr. E. Stechow. Journ. M.B.A. N.S. ix.
1910-13, p. 404.
On British Hydroids and Medusae. By E. T. Browne, B.A. Proceed. Zool.
Soc. London. 1896, part 1., p. 459.
On British Medusae. By E. T. Browne, B.A. Proceed. Zool. Soc. London.
1897, p. 816.
On Keeping Meduse Alive in an Aquarium. By E. T. Browne, B.a. Journ.
M.B.A. N.S. v. 1897-99, p. 176.
A New Method for Growing Hydroids in Small Aquaria by means of a Con-
tinuous Current Tube. By E. T. Browne. Journ. M.B.A. N.S. viii.
1907-10, p. 37.
Saphena mirabilis, Haeckel. By J. T. Cunningham, m.a. Journ. M.B.A.
N.S. u. 1891-92, p. 194.
172 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
A Further Note on the Gonadial Grooves of a Medusa, Awrelia aurita. By
T. Goodey, B.sc. Proc. Zool. Soc., 1909, p. 78.
On a Species of Siphonophore observed at Plymouth. By J. T. Cunning-
ham, M.A. Journ. M.B.A. N.S. un. 1891-92, p. 212.
Muggica atlantica. By J. T. Cunningham, m.a. Journ. M.B.A. NS. ii.
1891-92, p. 398.
On the Distribution and the Migrations of Muggiea atlantica, Cunningham,
in the English Channel, the Irish Sea, and off the South and West
Coasts of Ireland in 1904. By L. H. Gough, pH.p., Conseil Perm. In-
ternat. pour |’Explor. d. 1. Mer. Publications de Circonstance, No. 29.
1905, p. 1.
SPONGES.
Notes on Plymouth Sponges. By George Bidder. Journ. M.B.A. N/S. vi.
1902, p. 376.
Note on a Sieve-like Membrane across the Oscula of a Species of Leucosolenia.
By E. A. Minchin, m.a. Quart. Journ. Micr. Sci., vol. xxxii. 1892,
p. 251.
The Characters and Synonymy of the British Species of Sponges of the Genus
Leucosolenia. By E. A. Minchin, m.a. Proceed. Zool. Soc. Lond., vel. ii.
1904, p. 349.
The Collar-cells of Heterocoela. By George Bidder. Quart. Journ. Micr. Sci.,
vol. xxxvill. 1895-96, p. 9.
The Skeleton and Classification of Calcareous Sponges. By George Bidder.
Proceed. Roy. Soc., vol. lxiv. 1898, p. 61.
Studies in Spicule Formation. Parts i-iv. By W. Woodland. Quart.
Journ. Mier. Sci., vol. xix. 1905, pp. 231 and 533.
Studies in Spicule Formation. By W. Woodland. v.—The Scleroblastic
Development of the Spicules in Ophiuroidea and Kchinoidea, and in the
Genera Antedon and Synapta. vi.—The Scleroblastic Development of
the Spicules in-some Mollusca, and in one Genus of Colonial Ascidians.
Quart. Journ. Micr. Sci., vol. i. 1907, pp. 31-53.
Studies in Spicule Formation. By W. Woodland. vii.—The Scleroblastic
Development of the Plate-and-Anchor Spicules of Synapta, and the
Wheel Spicules of the Auricularia Larva. Quart. Journ. Micr. Sci.,
vol. li. 1907, p. 483.
A Preliminary Consideration as to the possible Factors concerned in the
Production of the various Forms of Spicules. By W. Woodland. Quart.
Journ. Micr. Sci., vol. li. 1907, pp. 55-79.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 173.
PROTOZOA.
Contributions to the Life-History of the Foraminifera. By J. J. Lister, M.a.
Phil. Trans. Roy. Soc., vol. clxxxvi. 1895, p. 401.
The Foraminifera of the Exe Estuary. By R. H. Worth. Journ. M.B.A.
N.S. vi. 1902, p. 336.
Observations on the Gregarines of Holothurians. By E. A. Minchin, B.a.
Quart. Journ. Micr. Sci., vol. xxxiv. 1893, p. 279.
Life History of Sporozoa. By H. M. Woodcock, B.sc. Brit. Assoc. Report,
Belfast, 1902.
Studies on some Sporozoan Parasites of Sipunculoids. I. The Life-History
of a New Actinomyxidian, Tetractinomyxon intermedium g. et sp. nov.
By I. Ikeda. Arch. f. Protistenkunde, Bd. 25. 1912, p. 240.
On Myxosporidia in Flat-fish. By H. M. Woodcock, B.sc. Report for 1903
on the Lancashire Sea Fisheries Laboratory, p. 46.
On Cystobia irregularis (Minch.) and Allied “ Neogamous ” Gregarines. By
H. M. Woodcock, B.sc. Arch. Zool. Expér. et Gén. Notes et Revue,
1904, No. 8.
The Life-Cycle of “ Cystobia”’ irreqularis (Minch.), together with Observa-
tions on other ‘‘ Neogamous”’ Gregarines. By H. M. Woodcock, B.sc.
Quart. Journ. Micr. Sci., vol. ]. 1906, p. 1.
Notes on the Choanoflagellate Genera Salpingoeca and Polyoeca, with Descrip-
tion of Polyoeca dumosa, sp. n. By J. 8S. Dunkerly, B.sc. Ann. and
Mag. Nat. Hist., Ser. 8, vol. v. 1910, p. 186.
Note on our Present Knowledge of the Choanoflagellata. By J. 8. Dunkerly,
B.sc. Journ. Quekett Micro. Club. 1910, p. 19.
Some Observations on Acinetaria. By C. H. Martin. Quart. Journ. Mier.
Sci., vol. li. 1909, p. 629.
FAUNISTIC AND GENERAL PAPERS.
Preliminary Report upon the Fauna and Flora of Plymouth Sound. By
Walter Heape, m.a. Journ. M.B.A. Old Series, No. 2. 1888, p. 194.
Notes on the Marine Invertebrate Fauna of Plymouth for 1892. By W.
Garstang, M.A. Journ. M.B.A. N.S. ii. 1891-92, p. 333.
Faunistic Notes at Plymouth during 1893-94. I. Faunistic Records, p. 212.
II. Notes on the Breeding Seasons of Marine Animals at Plymouth,
p- 222. ILI. Materials for a Calendar of the Floating Fauna, p. 229.
By W. Garstang, mM.a. Journ. M.B.A. N.S. im. 1893-95.
On some New or Rare Marine Animals discovered on the Coast of Devonshire.
By W. Garstang, M.A. Trans. Devon. Assoc. 1892, p. 377.
Notes on the Plankton observed at Plymouth during June, July, August, and
174 LiST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
September, 1892. By E. J. Bles, B.sc. Journ. M.B.A. N.S. ii. 1891-92,
p. 340. :
Faunistic Notes, January to June, 1895. By E. J. Allen, B.sc. Journ.
M.B.A. N.S. iv. 1895-97, p. 48.
Notes on Dredging and Trawling work during the latter half of 1895. By
K. J. Allen, B.sc. Journ. M.B.A. N.S. iv. 1895-97, p. 164.
Notes on the Pelagic Fauna at Plymouth, August-December, 1895. By
T. V. Hodgson. Journ. M.B.A. N.S. iv. 1895-97, p. 173.
On the Changes in the Pelagic Fauna of Plymouth during September, 1893
and 1895. By E. T. Browne, B.a. Journ. M.B.A. N.S. iv. 1895-97,
p- 168.
On the Pelagic Fauna of Plymouth, September, 1897. By E. T. Browne, B.A.
Journ. M.B.A. N.S. v. 1897-99, p. 186.
On the Fauna and Bottom-deposits near the 30-fathom line from the Eddy-
stone to Start Point. With seven Tables and sixteen Charts. By E. J.
Allen, B.sc. Journ. M.B.A. N.S. v. 1897-99, p. 365.
The Bottom-Deposits of the English Channel from the Eddystone to Start
Point, near the 30-fathom line. By R. H. Worth. Trans. Devon,
Assec., xxxi. 1899, p. 356.
On Rock Remains in the Bed of the English Channel. An Account of the
Dredgings carried out by s.s. Oithona in 1906. By L. R. Crawshay, M.a.
Journ. M.B.A. N.S. viii. 1907-10, p. 99.
The Dredgings of the Marine Biological Association (1895-1906), as a Con-
tribution to the Knowledge of the Geology of the English Channel. By
R. Hansford Worth. Journ. M.B.A. N.S. viii. 1907-10, p. 118.
On the Fauna of the Outer Western Area of the English Channel. By L. R.
Crawshay, M.A. Journ. M.B.A. N.S. ix. 1910-13, p. 292.
The Fauna of the Salcombe Estuary. By E. J. Allen, p.sc., and R. A. Todd,
B.sc. Journ. M.B.A. N.S. vi. 1900, p. 151.
The Fauna of the Exe Estuary. By E. J. Allen, p.sc., and R. A. Todd, B.sc.
Journ. M.B.A. N.S. vi. 1902, p. 295.
Plymouth Marine Invertebrate Fauna: Being Notes of the Local Distribution
of Species occurring in the Neighbourhood. Compiled from the Records
of the Laboratory of the Marine Biological Association. Journ. M.B.A.
N.S. vu. 1904-06, p. 155.
Report of a Trawling Cruise in H.M.S. Research off the South-west coast of
Ireland. By G. C. Bourne, M.a., with addendum by the Rev. Canon
Norman, r.r.s. Journ. M.B.A. N.S. 1. 1889-90, p. 306.
Report on the Surface Collections made by Mr. W. T. Grenfell in the North
Sea and West of Scotland (with Plate XXV.). By G. C. Bourne, Ma.
Journ. M.B.A. N.S.i. 1889-90, p. 376.
Report on the Surface Drift of the English Channel and Neighbouring Seas
for 1897. By W. Garstang, ma. Journ. M.B.A. N.S. v. 1897-99.
page
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 175
Principal Results of the Experiments with Bottom-Trailers. By G. P.
Bidder. Conseil Perm. Internat. Explor. Mer. Rapp. et Proc. Verb.,
vol. vi. 1906, p. xxxv.
Physical Investigations. By H. N. Dickson. Journ. M.B.A. N.S. 1. 1891-
92, pp. 159, 272.
Notes on Meteorological Observations at Plymouth. By H. N. Dickson.
Journ. M.B.A. N.S. ii. 1891-92, p. 171.
Microscopic Marine Organisms in the Science of Hydrography. By Prof.
P. T. Cleve. Journ. M.B.A. N.S. iv. 1895-97, p. 381.
Plankton and Physical Conditions of the English Channel. First Report of
the Committee, consisting of Prof. E. Ray Lankester (Chairman), Prof.
W. A. Herdman, Mr. H. N. Dickson, and Mr. W. Garstang (Secretary),
appointed to make Periodic Investigations of the Plankton and Physical
Conditions of the English Channel during 1899. Report Brit. Assoc.
$y L899.
Notes on the Physical Conditions existing within the Line from Start Point
to Portland. By H. M. Kyle, p.sc. Journ M.B.A. N.S. vi. 1903,
p- 528.
Report on the Physical Conditions in the English Channel, 1903. By Donald
Matthews. Internat. Fish. Investigations. Mar. Biol. Assoc. Report L.,
1902-03 (Cd. 2670). 1905, p. 289.
‘The Surface Waters of the North Atlantic Ocean, South of 60° N. Latitude,
September, 1904, to December, 1905. By Donald J. Matthews. In-
ternat. Fish. Investigations. Mar. Biol. Assoc. Report II. Part I.
1904-05 (Cd. 3837). 1907, p. 269.
Report on the Physical Conditions in the English Channel and Adjacent
Waters, 1904 and 1905. By Donald J. Matthews. Internat. Fish.
Investigations. Mar. Biol. Assoc. Report H. Part 2, 1904-05 (Cd.
4641). 1909, p. 279.
Report on the Physical Conditions in the English Channel and Adjacent
Waters, 1906, with a Note on the Mean Conditions for 1903-1909. By
Donald J. Matthews. Internat. Fish. Investigations. Mar. Biol. Assoc.
Report III. 1906-08 (Cd. 5546). 1911, p. 269.
Report on the Plankton of the English Channel, 1903. By Lewis H. Gough,
PH.D. Internat. Fish. Investigations. Mar. Biol. Assoc. Report I.
1902-03 (Cd. 2670). 1905, p. 325.
Report on the Plankton of the English Channel in 1904 and 1905. By
Lewis H. Gough, pH.p. Internat. Fish. Investigations. Mar. Biol.
Assoc. Report II. Part 1, 1904-05 (Cd. 3837). 1907, p. 165.
Report on the Plankton of the English Channel in 1906. By W. Bygrave,
B.A. Internat. Fish. Investigations. Mar. Biol. Assoc. Report III.
1906-08 (Cd. 5546). 1911, p. 235.
On the Artificial Culture of Marine Plankton Organisms. By E. J. Allen,
p.sc., and KE. W. Nelson. Journ. M.B.A. N.S. vii. 1907-10, p. 421.
176 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
On the Artificial Culture of Marine Plankton Organisms. By E. J. Allen,
p.sc., and EK. W. Nelson. Quart. Journ. Micr. Sci., vol. lv. 1910, p. 361.
On the Oxidation of Ammonia in Sea Water. By G. P. Darnell-Smith.
Journ. M.B.A. N.S. in. 1893-95, p. 304.
On the Action of Nicotine on Certain Invertebrates. By Marion Greenwood.
Journ. Physiol., vol. xi. 1890, p. 573.
Notes on some Animal Colouring Matters. By C. A. MacMunn, M.a., M.D.
Journ. M.B.A. N.S. 1. 1889-90, p. 55.
Contributions to Animal Chromatology. By C. A. MacMunn, M.a., M.D.
Quart. Journ. Micr. Sci., vol. xxx. 1890, p. 51.
A Note on some attempts to cause the Formation of Cytolysins and Pre-
cipitins in certain Invertebrates. By G. H. Drew, B.a. Journ. of
iEiysiene,,volxa.” 91, praise:
A Note on the Application of Giemsa’s Romanowsky Stain to the Blood and
Tissues of Marine Invertebrates. By G. H. Drew, B.A. Parasitology,.
WO sine LOH aay.192
The Relation of the Heart-Beat to Electrolytes and its Bearing on Com-
parative Physiology: By G. R. Mines. Journ. M.B.A. N.S. ix. 1910-
os Demeliple
An Aid in the Study of Nematocysts. By T. H. Taylor, m.a. Proc. Roy.
Phys. Soc. Edin., vol. xviii. 1912, p. 235.
Photogenic Bacteria. By J. E. Barnard. Trans. Jenner Inst. Preven. Med.
1899. seri. p: ole
A Table showing certain Cultural Characteristics of some of the Commonest
Bacteria found in the Laboratory Tanks at Plymouth. By G. H. Drew,
Bal Journ WBA” IN Swix, 1 1O-o pe Ge
The Action of some Denitrifying Bacteria in Tropical and Temperate Seas,,.
and the Bacterial Precipitation of Calcium Carbonate in the Sea. By
G. H. Drew, B.A. Journ. M.B.A. N.S.ix. 1910-13, p. 142.
On the Precipitation of Calcium Carbonate in the Sea by Marine Bacteria,
and on the Action of Denitrifying Bacteria in Tropical and Temperate
Seas. By G. H. Drew, B.a. Journ. M.B.A. N.S. ix. 1910-13, p. 479.
A Deep-sea Bacteriological Water-bottle. By Donald J. Matthews. Journ.
M.B.A. N.S. ix. 1910-13, p. 525.
VARIATION.
The Variations occurring in Certain Decapod Crustacea. I. Crangon vulgaris..
By W. F. R. Weldon, m.a. Proceed. Roy. Soc., vol. xlvi.., p. 445.
Certain Correlated Variations in Crangon vulgaris. By Professor Weldon,
F.R.S. Proceed. Roy. Soc., vol. li. 1892, p. 1.
Certain Correlated Variations in Carcinus maenas. By Professor Weldon,
F.R.S. Proceed. Roy. Soc., vol. liv. 1893, p. 318.
LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES. 177
An Attempt to Measure the Death-rate due to Selective Destruction of
Carcinus maenas, with Respect to a Particular Dimension. By Prof.
Weldon, F.R.s. Proceed. Roy. Soc., vol. lvu. 1895, p. 360.
Remarks on Variation in Animals and Plants. By Prof. Weldon, F.R.s.
Proceed. Roy. Soc., vol. lvii. 1895, p. 379.
Presidential Address to the Zoological Section (on Natural Selection and
Variation). By Professor Weldon, r.r.s. Report Brit. Assoc. 1898.
On the Variation of the Tentaculocysts of Aurelia aurita. By E. T. Browne,
B.A. Quart. Journ. Micr. Sci., vol. xxxvu. 1894-95, p. 245.
Variation in Aurelia aurita. By E. T. Browne. Biometrica, vol. 1., No. 1,
pe 90:
On the Variation of Haliclystus octoradiatus. By KE. T. Browne, B.A. Quart.
Journ. Micr. Sci., vol. xxxvi. 1895-96, p. 1.
Preliminary Report of the Results of Statistical and Ichthyological Investi-
gations made at the Plymouth Laboratory. By Georg Duncker, pu.p.
Journ. M.B.A. N.S. v. 1897-99, p. 172.
Quantitative Studies in the Evolution of Pecten. III. Comparison of Pecten
opercularis from three localities of the British Isles. By C. B. Daven-
port. Proceed. American Acad. Arts and Sci., vol. xxxix. 1903, p. 123.
Evolution without Mutation. By C. B. Davenport. Journ. Experim. Zool.,
vol u.. 1905, p. 137:
Botanical Publications.
The Flora of Plymouth Sound and Adjacent Waters (with a woodcut). By
Prof. T. Johnson, B.sc. Journ. M.B.A. N.S.1i. 1889-90, p. 286.
On the Systematic Position of the Dictyotaceae, with special reference to the
Genus Dictyopteris, Lamour. By Prof. T. Johnson, B.sc. Journ. Linn.
Soc. Botany, vol. xxvii. 1890, p. 463.
Studies in the Dictyotaceae. III. The Periodicity of the Sexual Cells in
Dictyota dichotoma. By J. Ll. Williams. Annals of Botany, vol. xix.
1905, p. 531.
Observations on Brown and Red Sea-weeds. By Prof. T. Johnson. Rep.
Brit. Assoc. 1890.
On the Structure of the Thallus of Delesseria sanguinea (with Plates XVII.
and XVIII). By M. C. Potter, ma. Journ. M.B.A. N.S.i. 1889-90,
joped eras
The Callosities of Nitophyllum versicolor. By Prof. T. Johnson. Journ.
Roy. Dublin Soc. 1892.
Observations on the Phaeozoosporeae. By Professor T. Johnson. Ann. Bot.,
vol. v. 1891.
Halosphaera viridis, Schmidt. By H. Thompson, B.A. Journ. M.B.A. N.S.1.
1889-90, p. 341.
178 LIST OF PUBLICATIONS RECORDING THE RESULTS OF RESEARCHES.
The Polymorphy of Cutleria multifida. By A. H. Church, B.a. Ann. Bot.,
vol. xu. No. 45. 1898, p. 75.
Algological Notes, by G. Brebner. Journ. M.B.A. N.S. iv. 1895-97,
pp. 179, 286.
On some Endophytic Algae. By A. D. Cotton. Journ. Linn. Soc. Botany,
vol. xxxvu. 1906, p. 288.
Some British Species of Phaeophyceae. By A. D. Cotton. Journ. Botany,
vol. xlv. 1907, p. 368.
The Reproduction and Early Development of Laminaria digitata and Lamin-
aria saccharina. By G. H. Drew, B.a. Annals of Botany, vol. xxiv.
1910, p. 177.
Contributions to the Knowledge of the Laminarias (Beitrage zur Kenntnis
der Laminarien).’ By C. Kilian. Zeits. f. Bot. 1911.
[ 179 ]
Recherches sur le Developpement post-embryonnaire
de la Langouste commune (Pa/inurus vulgaris).
Par
M. E.-L. Bouvier,
Professeur au Muséum d'Histoire Naturelle a Paris.
Avec 6 Figures dans le Texte.
C’estT surtout pour étudier le développement post-embryonnaire de la
Langouste commune (Palinurus vulgaris Latr.) que je me suis rendu au
Laboratoire de Plymouth. L’endroit me semblait excellent parce
que la Langouste n’est pas rare prés des cdtes dans les eaux du Devon-
shire et de la Cornouaille, parce qu’elle est principalement fréquente sur
les fonds rocheux au-dessus desquels se dresse le phare d’Eddystone,
aussi enfin, parce que le Laboratoire de Plymouth est trés bien installe,
avec un bateau, l’Orthona, qui peut se rendre en mer chaque jour et
effectuer les péches les plus diverses.
Car il fallait pécher souvent et & toutes profondeurs pour atteindre le
but que je métais fixé, et ce but n’était rien moins que de découvrir
les stades jusqu’alors inconnus du développement de notre Langouste.
Depuis les observations de Couch (1857, 25) justifiées par Gerbe (1858,
547) et par Dohrn (1870), mais a tort contestées par Sp. Bate (1868),
on sait que le P. vulgaris sort de lceuf sous une forme larvaire foliacée,
hyaline, aplatie dans le sens dorso-ventral, que les anciens zoologistes
avaient appelée phyllosome et tenaient pour un genre spécial de Crus-
tacés décapodes. On savait aussi, depuis les recherches de Claus (1863),
que le phyllosome acquiert progressivement des appendices 4 mesure
quwil se développe, qu’il peut attemdre une longueur de 21 mm., et
qu il garde jusque dans sa plus grande taille les caractéres généraux
qui lui sont propres et qui en font un organisme essentiellement
pélagique. Mais quelle est la série des stades présentés par le phyl-
losome depuis la sortie de Vceuf jusqu’au moment ot il acquiert la
forme longue, trapue, et rétrécie des Decapodes normaux ? et comment
s’effectue le passage a cette forme ? Autant de questions quil fallait
.Se poser et que personne encore n’avait pu résoudre. A vrai dire, depuis
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914, M
180 M. E.-L. BOUVIER.
les belles recherches de M. Boas (1881) récemment confirmées par M.
Calman (1909), on était en droit de croire que le passage du phyllosome
a la forme deéfinitive s’effectue par le moyen d’un “stade natant”
désigné jadis par M. Ortmann (1897) sous le nom de puerulus et con-
sidéré par cet auteur comme un genre autonome de Palinurien. J’ai
moi-méme apporté ma contribution (1912) aux travaux de ces auteurs
et je connais actuellement le puerulus supposé d'une dizaine d’espéces
de Langoustes. Mais ces Langoustes sont toutes exotiques, et d’ailleurs,
cest par une hypothése rationnelle, mais non a la suite d’une obser-
vation directe, que l’on s’accorde a voir dans le puerulus le stade inter-
médiaire qui conduit du phyllosome a l’état de Langouste parfaite. I]
convenait par suite de justifier les suppositions de M. Boas et de
chercher & connaitre tous les stades évolutifs ainsi qve le puerulus de
lespéce localisée dans nos mers. [1 fallait aussi chercher l’habitat des
puerulus ; car ces organismes, au contraire des phyllosomes, sont d’une
rareté extréme, et c est tout au plus si l’on en posséde une trentaine
d’exemplaires, pour la totalité du groupe des Palinuriers.
La saison d’été m’a paru plus propre que toute autre a la solution de
ces problémes, car c’est dans la seconde quinzaine de juin et au début de
juillet que M. Cunningham (1891-92) captura autour du phare d’Eddy-
stone les premiers stades larvaires du P. vulgaris. Mon savant prédé-
cesseur a trés bien décrit et figuré ces stades, mais, peu favorisé par le
temps, il n’a pu en obtenir que deux, et les péches faites dans la suite
ont été infructueuses, alors qu’elles auraient dt lui procurer la capture
des stades plus Agés. C’est dans l’espoir d’obtenir ces stades que je me
suis installé & Plymouth du 15 juillet au 1€ septembre. Le bref exposé
qu’on va lire montrera que le moment était bien choisi; j’ajouterai,
d’ailleurs, que je fus étrangement favorisé par une saison des plus propices.
I. STADES PHYLLOSOMES DE LA LANGOUSTE COMMUNE.
Je vais indiquer tout d’abord les stades phyllosomes obtenus par
l'Outhona au cours decet te saison de péches. L’étude n’en est pas
encore achevée et c est provisoirement que je les classe en série de la
maniére suivante :
Stade 7 (3 mm. environ). Antennules et antennes presque indivises,
de longueur a peu prés égale. Le bouclier céphalique atteint a peine la
base des maxillipédes postérieurs (map. 3) ; exopodite des péréiopodes 3
(p. 3) dépourvu de soies, péréiopodes des deux paires suivantes (p. 4,
p. 5) a Vétat de bourgeons trés courts. Abdomen sans appendices
visibles et sans articulations bien distinctes en dehors du telson. Ce
DEVELOPPEMENT POST-EMBRYONNAIRE DE LA LANGOUSTE. 181
stade a été parfaitement figuré par M. Cunningham dans la premiére
figure de son mémoire ; il est celui que présente le phyllosome a sa sortie
de Voeuf.
Stade 2 (4 4&5 mm.). Un court bourgeon représente le fouet interne
des antennules ; p. 5 et surtout p. 4 plus allongés qu’au stade précédent ;
des uropodes légérement échancrés au bout et atteignant au plus le milieu
du telson, qui est tronqué en arriére; la segmentation de l’abdomen
encore trés vague.
Stade 3 (6 a 8 mm.). La portion pédonculaire des antennules est
divisée en deux articles, le fouet interne égale environ un tiers du
fouet externe. Le pédoncule des antennes est indivise, et un peu
plus court que le fouet, qui est également indivise. Le céphalon
recouvre la base de map. 3; map. 2 avec un bourgeon exopodial.
Des soies & l’exopodite de p. 3, p. 4 avec un exopodite nu. Des
pléopodes representés par un bourgeon aplati et échancré en arriére ;
uropodes plus longs qu’au stade 2 et profondément échancrés en deux
rames; segmentation de l’abdomen bien distincte, surtout dans les
régions épimérales. C’est le dernier stade observé par M. Cunningham,
qui l’a bien décrit et fort exactement figure.
Stade 4 (9 mm.). Le pédoncule antennulaire commence a montrer
une division en 3 articles. Il y a déja quelques soies sur |’exopodite de
p. 4; cette patte & peu prés aussi longue que l’abdomen. Les pléopodes
sont nettement biramés; le telson est arrondi sur son bout distal et
légérement plus long que les uropodes dont l’exopodite présente une
trés nette échancrure externe.
Stade § (10 mm.). Le pédoncule antennulaire est nettement divisé
en 3 articles ; les antennes sont un peu plus longues que les antennules.
L’exopodite de p. 4 atteimt presque le bout de l’endopodite ou, tout au
moins, en dépasse le milieu.
Stade 6 (12-13 mm.). Le fouet interne des antennules égale a peu
prés la moitié du fouet externe ; le fouet antennaire égale une fois et
demie la longueur de son pédoncule. L’exopodite de map. 2 atteint
lextrémité distale de V’article suivant ; p. 6 arrive a peine a la base des
uropodes ; les soies de p. 4 bien développées.
Stade 7 (14-15 mm.). Le fouet antennaire égale prés de deux fois la
longueur du pédoncule ; map. 7 est déja long ; l'exopodite de map. 2
dépasse l’extrémité distale de l’article suivant. Ce stade a été assez
bien figuré par Claus (1863, Taf. XXVI, fig. 7) et avec quelques
erreurs par J. Couch (1858).
Stade 8. N’a pas encore été trouvé.
182 M. E.-L. BOUVIER.
Stade 9 (20-21 mm.). (Fig. 1.) Le fouet interne des antennules égale
presque le fouet externe ; les antennes sont a peu prés aussi longues que le
céphalo-thorax, et leur fouet, otl’on voit déja des traces de segmentation,
égale environ trois fois la longueur du pédoncule. L’exopoditedes machoires
est bien développé. Exopodite de map. 7 long et formé de 2 articles,
toutes les autres parties de l’appendice (sauf probablement l’épipodite)
sont bien indiquées mais réduites ; exopodite de map. 2 a peu prés aussi
long que l’endopodite, mais dépourvu de soies. Appareil branchial
formé des mémes parties que celui de ladulte, mais les épipodites de
map. 1 et mxp. 2 font probablement défaut ; le:céphalon recouvre la
Fic. 1.—Phyllosome de P. vulgaris 4 avant-dernier stade (stade 9) capturé pres du
phare d’Eddystone. Photographié au Laboratoire d’entomologie du Muséum par M. Boyer.
(Cliché communiqué par ‘‘ Science et Vie”.) Grandeur naturelle.
base de p. 7. Les épiméres abdominaux sont toujours arrondis, les
pléopodes ont un pédoncule trés net. Les pédoncules oculaires, grace
& leur tigelle fort longue, atteignent le bout distal des antennules et
dépassent le pédoncule des antennes. C’est le dernier stade observe
jusqu’ici; Claus en a donné la description et la figure (1863, Taf.
XXVI, fig. 8); ila été passablement représenté par Spence Bate (1863,
fig. 1).
Stade 10 (20-21 mm.). Ce stade trés intéressant était resté inconnu,
non seulement dans notre Langouste commune, mars chez tous les Palinu-
ridés. On en trouvera ci-contre la figure (fig. 2). Ce qui le distingue
essentiellement, c’est la structure de l’abdomen qui se rapproche deja
beaucoup de celle de la Langouste adulte ; car le telson présente deux
A
map* \
\
yale SNE EP EE. BE Ss
{ sea RBRy.
CS
Fic, 2.—Phyllosome de P. vulgaris au dernier stade (stade 10) et montrant le puerulus
qui commence a s’en dégager. Sous la carapace un peu déformée du phyllosome se voit le
bouclier céphalo-thoracique du puerulus, un pédoneule oculaire de ce dernier est sorti du
pédoncule phyllosomien, l’autre est encore coiffé de son exuvie; certaines pattes com-
mencent également a se dégager. Dessin de l’auteur d’aprés un exemplaire capturé dans les
parages d’Eddystone. (Le cliché a été communiqué par “Science et Vie”.) Gross. 4.
184 M. E.-L. BOUVIER.
paires d’épines et les épiméres abdominaux se terminent en pointe avec
un denticule sur leur bord postérieur. Les longs fouets antennaires
présentent des traces de segmentation et quelques soies ; les épipodites
de map. 1 et mxp. 2 sont développés, la formule branchiale est celle de
ladulte et beaucoup de branchies présentent deja quelques bourgeons.
Je n’ai pu obtenir qu’un phyllosome a ce stade; il fut capturé entre
deux eaux le 25 aotit 1913, a 5 milles E.N.E. du phare d’Eddystone.
J’ai examiné les matériaux recueillis au cours de 46 péches effectuées
depuis le 20 juin 1913, jusqu’a la fin d’aott. La plupart des péches
faites dans les parages d’Eddystone renfermaient des phyllosomes de
Palinurus vulgaris et de Scyllarus arctus ; celles pratiquées en dehors
de cette zéne ne donnérent aucun représentant de ces larves. Les péches
du mois de juin ne fournirent que de jeunes phyllosomes de Palinurus,
mais je dois observer qu’au Laboratoire on avait conservé peu de ma-
tériaux de ces péches ; & mesure qu'on avangait en juillet, les phyllo-
somes 4gés devenaient nombreux et strement |’évolution peut s’achever
durant ce mois,.comme on le verra plus loin. D’ailleurs, durant
toute la durée du mois d’aotit, la pécha rapporta des phyllosomes
dgés et des phyllosomes aux premiers stades; on peut donc affirmer
que la Langouste commune, dans les parages d’Eddystone, effectue
son développement post-embryonnaire au moins pendant toute la durée
de V’été, c’est-a-dire du 21 juin au 21 septembre.
II. StapE NATANT ov PUERULUS.
Caractéres du puerulus. Pour des raisons que j’indiquerai plus loin,
la capture de l’exemplaire précédent a une importance de premier ordre,
au point de vue de la solution des problémes qui nous occupent ; elle
doit étre mise sur le méme rang qu'une seconde dont je vais tout de
suite entretenir le lecteur.
Cette seconde capture est celle d’un puerulus qui fut pris le 31 juillet,
entre deux eaux, dans les parages compris entre Looe et Eddystone,
au-dessus d’un fond de 27-29 brasses. L’exemplaire fut trouvé par
M. Gossen parmi les matériaux recueillis au cours de péches que dirigeait
M. Clark, Assistant du Laboratoire. Faut-il dire que j’éprouvai une
joie profonde lorsqu’on apporta sur ma table de travail ce puerulus qui
avait jusqu’alors échappé a la connaissance des zoologistes ?
L’unique et précieux exemplaire (figs. 3, 4, 5, 6) mesure environ 2] mm.
de longueur, ce qui est la taille des grands phyllosomes. Comme tous les
puerulus, il est hyalin, avec des téguments coriaces & peu prés totalement
dépourvus de calcification, et la forme macrourienne normale. II] se
DEVELOPPEMENT POST-EMBRYONNAIRE DE LA LANGOUSTE. 185
distingue pourtant des puerulus actuellement connus par son bouclier
céphalo-thoracique reguliérement convexe, mais il est possible que cette
disposition soit due au renflement des régions branchiales sous l’action de
Yeau de mer ot l’animal a péri, ou des liquides conservateurs ; dans les
autres puerulus, en effet, la carapace est trés peu convexe dorsalement,
et ses régions branchiales forment un angle presque droit avec la région
dorsale, disposition qui s’est conservée chez un certain nombre de
Palinuridés primitifs (Puerulus Ortm.; Linuparus Gray). D/ailleurs,
notre puerulus est bien au “stade natant ”’ décrit par M. Boas, car ses
Fig. 3. Fig. 4.
Fic. 3.—Puerulus de P. vulgaris capturé dans les parages d’Eddystone. Face dorsale
(Vaprés une photographie de M. Martin Duncan prise au Laboratoire de Plymouth).
Grandeur naturelle.
Fic. 4.—Puerulus de la Fig. 3, vu du cdté ventral (d’aprés une photographie de
M. Martin Duncan).
pléopodes peuvent se conjuguer par couples dans une méme paire,
erace aux rétinacles a crochets qui occupent le bout distal de l’'appendice
interne situé sur leur rame endopodiale.
L’exemplaire capturé présente déja de grandes resemblances avec
la forme définitive du Palinurus vulgaris ; les antennules sont du méme
type brévicorne, c’est-a-dire terminées par deux courts fouets subégaux
dont l’externe est beaucoup plus épaissi que l'autre ;—les antennes
sont trés fortes, avec un long et puissant fouet bien articulé et un large
186 M, E:-lL. BOUVIER.
Fic 5.—Puerulus des deux figures précédentes vu du cdté dorsal. (Agrandissement
photographique obtenu par M. Martin Dunein.)
DEVELOPPEMENT POST-EMBRYONNAIRE DE LA LANGOUSTE. 187
pédoncule ot les épines sont distribuées 4 trés peu prés comme chez la
Langouste adulte ;—les pédoncules oculaires sont courts et larges ;—
le rostre est réduit 4 une faible pointe médiane comme dans les espéces
du genre Palinurus ;—les cornes rostrales sont trés puissantes et suivies
d’une paire d’épines post-rostrales ;—il y a sur la carapace quelques
épines qu’on retrouve chez l’adulte (une rangée transverse de quatre
épines gastriques, une paire de spinules cardiaques, et, au bord supérieur
de chaque région branchiale, une dizaine de spinules disposées en série)—
les épiméres abdominaux sont aigus et, sauf le premier, munis d’une
saillie en pointe sur leur bord postérieur ;—on observe une paire de
fortes pointes sur le 6° segment abdominal, a la naissance du telson ;—
ce dernier présente déja la paire d’épines proximales et les échancrures
latérales épineuses de la Langouste adulte ;—les uropodes sont munis,
comme dans cette derniére, d’échancrures externes spinuleuses, les pattes
enfin sont courtes, fortes, et dépourvues d’exopodites* bien développés.
Il y a pourtant de profondes différences entre ce puerulus et la forme
définitive de la Langouste commune; outre les caractéres généraux
propres & tous les puerulus (corps hyalin, téguments coriaces et non
calcifiés ; présence de rétinacles sur les appendices internes des pléo-
podes) il faut signaler surtout l’absence de denticulations aigués sur
les cornes rostrales (fig. 6), le développement de soies assez longues sur
les fouets antennaires, l’absence de sillons transverses sur les segments
abdominaux et surtout armature épineuse de la carapace qui est loin
d’étre riche et puissante comme dans la Langouste adulte. J’ai montré
plus haut que les épines du puerulus se retrouvent a leur place dans
la forme définitive ; cela est vrai pour toutes, sauf peut-étre pour trois
épines, probablement hépatiques, situées de chaque cété en arriére des
antennes ; ces épines sont fortes et trés caractéristiques de notre puerulus,
mais il est difficile de leur trouver des homologues dans les nombreuses
épines qui ornent le bouclier céphalo-thoracique de l’adulte.
Le puerulus d’Eddystone se rapproche surtout d’un puerulus caraibe
que j’ai rapporté (1912, 81) au Palinurus longimanus Edw. ; il pré-
sente comme lui un exopodite flagellé sur les maxillipédes externes et
plusieurs paires d’épines sternales; ces derniéres, toutefois, sont plus
développées dans notre puerulus et d’ailleurs plus nombreuses, car on
en trouve une a la base des pattes des quatre paires postérieures tandis
que les épines se localisent a la base des trois derniéres paires de pattes
dans le puerulus caraibe.
* L’exemplaire avait perdu quelques-unes de ses pattes, mais celles qui restent sont
courtes et fortes comme dans les puerulus des autres Palinuridés.
188 M. E.-L. BOUVIER.
Ara AA
Nes Ar ee)
\ aes 4
. ”]
A A
i heey hy Chae
i apes | ‘
\ A
, 4
A
Fic. 6.—Esquisse du méme puerulus montrant les ornements en saillie de la face dorsal.
Dessin de l’auteur d’aprés l’exemplaire capturé dans les parages d’Eddystone. (Cliché com-
muniqué par ‘ Science et Vie ”.)
DEVELOPPEMENT POST-EMBRYONNAIRE DE LA LANGOUSTE. 189
Passage du phyllosome au puerulus.—Si le puerulus ressemble beau-
coup a la Langouste adulte, il ressemble par contre bien peu au phyllo-
some: avec ses pattes courtes de Crustacé marcheur, ses exopodites
thoraciques réduites & un imperceptible bourgeon dépourvu de soies,
ses pédoncules oculaires & tigelle trés courte, surtout avec son bouclier
céphalo-thoracique trapu et trés différent du large et plat bouclier
phyllosomien, le puerulus est aussi différent que possible de la forme
larvaire des Palinuridés. Provient-il réellement de cette forme et com-
ment s’effectue le passage de l’un & autre ? Voila ce qu'il fallait encore
trouver.
Par une bonne fortune singuliére et qu il ett été fou d’espérer, l’Orthona,
sous la direction de M. Clark, fit capture d’un phyllosome dans lequel
était en voie de se former et de se dégager le puerulus. Ce phyllosome
est celui (fig. 2) dont j’ai donné plus haut la description et qui représente,
a mon avis, le 10® stade larvaire de notre Langouste, un stade que les
zoologistes n’avaient pas encore observé. Son abdomen ressemble
déja tout a fait 4 celui du puerulus, mais le spécimen est bien phyllosome
par tous ses autres caractéres.
Ce phyllosome fut rapporté vivant par M. Clark qui me prévint de
suite; mais le délicate organisme avait succombé aux fatigues du
voyage et était complétement inerte quand j’arrivai au laboratoire pour
lexaminer. La nuit était venue, on le conserva dans l’alcool et j’en
fis étude le jour suivant. Sa carapace était déformée et ses pédoncules
oculaires avaient un aspect bizarre, si bien qu'il me parut étre tout d’abord
un phyllosome en mauvais état. Mais un examen plus attentif modifia
bien vite cette conception trop rapide: l’abdomen avait des caractéres
tout particuliers propres au puerulus, et sous le bouclier céphalo-thora-
cique déformé, on apercevait, comme une masse opaque, le bouclier
méme du puerulus, avec son rostre minuscule, ses cornes frontales, ses
fortes épines hépatiques et la plupart des spinules de la carapace (fig. 2).
Le pédoncule oculaire droit du puerulus était déja sorti du pédoncule
phyllosomien ; le pédoncule oculaire gauche était également formé,
indépendant de la tigelle phyllosomienne, pourtant coiffé encore du
pédoncule phyllosomien ; certaines pattes du puerulus commengaient
a se dégager des pattes phyllosomiennes.
En fait, c’était une piéce merveilleuse et singuliérement démonstrative
que permettait d’établir sans contestation possible : 1° que le phyllosome
capturé représente bien le dernier stade larvaire de notre Langouste ; 2° que
cette dermeére ne traverse pas, comme d autres Palinuridés, le curieux stade
PHYLLAMPHION décrit et figuré par Reinhardt en 1858 ; 3° que les con-
190 M. E.-E. BOUVIER.
ceptions de M. Boas sont parfaitement justes en ce sens que le puerulus est
bien directement issu du phyllosome, du moins dans notre Langouste
commune.
Par analogie, on devra étendre cette derniére et trés importante
conclusion a tous les Palinuridés, en remarquant toutefois que certaines
formes exotiques traversent un stade phyllamphion, assez peu different
dailleurs du phyllosome.
Passage du puerulus ad la Langouste-—Les observations précédentes
nous donnent-elles le droit de conclure que le puerulus d’Hddystone est
celui de la Langouste commune et, d’une maniére plus générale, que les
divers puerulus connus représentent le “stade natant” de divers
Palinuridés? Cela ne me parait point douteux. Le Palinurus vulgaris
représente a lui seul, dans nos mers, la famille des Palinuridés, d’ou cette
conclusion que tous les phyllosomes palinuriens capturés a Eddystone
proviennent bien de cette Langouste. Nous en dirons autant du
puerulus, car nous avons vu ce dernier prendre naissance au sein méme
des grands phyllosomes. Le puerulus d’Eddystone est donc, sans in-
certitude aucune, le “ stade natant ’ du Palinurus vulgaris.
Il s’en faut que l’on puisse conclure, avec une précision semblable,
lorsqu’on s’adresse aux autres formes de la famille, car on n’a jamais
observé, dans ces derniéres, la série compléte des stades phyllosomes
et moins encore le passage du phyllosome au puerulus. Mais j’ai large-
ment établi, dans un travail antérieur (1912), que chaque puerulus présente
des caractéres qui permettent de le rapporter, presque sirement, a une
espéce spéciale de Palinuridés.
III. HapirupDES DES PHYLLOSOMES ET DES PUERULUS.
Toutefois les suppositions les plus logiques ne valent pas une bonne
preuve et, en ce qui concerne la Langouste commune, il faudra observer
le passage du puerulus a la forme définitive. Ce sera l’objet principal
de mes recherches durant la campagne que je dois effectuer prochaine-
ment au laboratoire de Plymouth.
La principale difficulté sera d’obtenir des puerulus. On peut se les
procurer par deux moyens: soit en élevant des phyllosomes de grande
taille, soit en les capturant directement au large.
La premiére méthode sera sans doute la meilleure et la plus stire, car
lélevage en aquarium des grands phyllosomes ne semble pas devoir
étre trés difficile. M. Clark a capturé, dans les parages d’Hddystone,
un phyllosome & l’avant-dernier stade et l’a rapporté vivant au labora-
toire ou j’ai pu observer pendant les deux jours qui précédérent mon
DEVELOPPEMENT POST-EMBRYONNAIRE DE LA LANGOUSTE, 194
départ. Quoique placé dans une simple jarre et dans des conditions
peu favorables, la curieuse larve paraissait trés active et en fort bon
état ; elle se déplagait & peu prés exclusivement au moyen de ses exopo-
dites thoraciques, qui lui servaient aussi 4 se maintenir dans le milieu et
& la diriger ; elle descendait lentement quand ces appendices n’étaient
plus en fonction; les pattes elles-mémes font peu de mouvements et
semblent jouer le réle de balanciers, l’abdomen et ses pléopodes n’en
font aucun. Le jeune animal est rapidement et fortement attiré par
la lumiére. A cet avant-dernier stade, les phyllosomes sont assez com-
muns vers la fin de juillet et durant le mois d’aott ; en les élevant dans
un aquarium convenable, on pourra peut-étre les conduire jJusqu’au
dernier stade et de celui-ci au “ stade natant ”’ ou puerulus.
La capture des puerulus en pleine mer sera plus difficile. Ces jeunes,
en effet, ne doivent pas rester longtemps entre deux eaux, dans le
milieu ot ils se trouvent en sortant des phyllosomes, et ot fut capturé
lexemplaire que j’ai décrit plus haut. Ce sont des nageurs au corps
lourd, qui doivent tres vite descendre sur le fond* ov, ils se cachent certaine-
ment parma les rochers, car leurs téguments coriaces et non calcifiés jes
rendent trés vulnérables. Ainsi doit s’expliquer, 4 mon avis, l’extréme
rareté des puerulus dans les collections zoologiques et la diversité
habitat jusqu’icl connue chez ces animaux: les puerulus étudiés
par M. Boas avaient été, “en partie du moins, capturés au large ”
(1880, 84), et je sais, d’aprés les notes des péches faites par la Princesse
Alice, que le type du puerulus atlanticus (““ stade natant”? du Palinurus
regius Br. Cap.) fut capturé au trémail par 20 métres de profondeur,
a Ste. Lucie du Cap Vert. D’un autre coté, M. Calman rapporte que
le puerulus springer, Ortm. (“stade natant” du Palinurus ornatus
Fab.) fut trouvé a Vile Christmas “ soit au milieu des rochers, soit sur
le “ pier’ dans les crevasses des piles” (1909, 444), et j'ai noté ailleurs
(1912, 88) que le puerulus du Panulirus dasypus Latr. fut trouvé par
M. le Dr. Jousseaume dans les crevasses du rivage, a Djiboutil.
Quwils soient obtenus par élevage ou par capture directe, les puerulus,
a cause de leurs habitudes, se préteront certainement beaucoup mieux
que les phyllosomes a la captivité de Vaquarium. On pourra, sans
difficulté, j’en suis stir, les conduire jusqu’a la forme définitive de l’espéce
a laquelle ils appartiennent. Cette forme sera sans doute acquise a la
premiére mue, car les puerulus d’une espéce ont tous a peu prés la méme
* Tl en est, sans doute, de méme pour les Homards ; le bateau du laboratoire a capturé,
entre deux eaux, un jeune Homard qui avait acquis tous les caracteres definitifs de l’espece ;
le jeune venait stirement de sortir de sa mys7s qui est pélagique.
192 M. E.-L. BOUVIER.
taille, et cette taille n’est pas moins grande que celle des plus jeunes
Langoustes. En capturant a Djiboutil les puerulus du Panulirus dasypus,
M. Jousseaume a recueilli plusieurs jeunes de l’espéce, et ces jeunes
présentent la méme taille et les mémes variations de taille que les
puerulus ;* le Muséum d’histoire naturelle posséde un jeune exem-
plaire de la Langouste commune qui dépasse de 4 mm. seulement le
puerulus d’Eddystone, et l’on trouverait stirement des jeunes ayant la
méme taille que ce dernier. Quoiqu’il en soit, il n’est pas douteux que
du puerulus sortira la Langouste sous sa forme définitive.
J’arréte la cette note préliminaire qui sera complétée et détaillée a
la suite de mon prochain séjour au Laboratoire de Plymouth. $i, comme
je lespére, on lui trouve quelque intérét, je dois en remercier toutes les
personnes qui ont provoqué ou facilité mes recherches, c’est-a-dire les
membres de la ‘“‘ Marine Biological Association,” M. le Professeur Ray
Lankester qui me désigna comme “investigator”? au choix de cette
Société, et, pour leur dévouement au-dessus de tout éloge, M. Allen,
Directeur du Laboratoire de Plymouth, M. Clark, assistant, M. M. Gossen
et Savage attachés au service, et sans aucune exception le personnel du
Laboratoire. Je dois aussi remercier mon excellent confrére, M. F.
Martin Duncan, qui travaillait au Laboratoire durant mon séjour a
Plymouth et qui a trés obligeamment photographie, peu aprés sa capture,
le précieux puerulus recueilli par l’Octhona.
INDEX BIBLIOGRAPHIQUE.
1868. BATE, C. Spence. Carcinological Gleanings. No. IV. Ann. and
Mag. Nat. Hist. (4). Vol. II, pp. 116, 117, Pl. X figs. 1 et 2.
1880. Boas, J. E. V. Studier over Decapodernes Slaegtskabsforhold.
Vid. Selsk. Skr. X, 6 R., nat. og mat. Afd. 1 et 2, pp. 78-85.
1912. Bouvier, E. L. Le stade “ natant ”’ ou “ puerulus ” des Palinuridés.
Trans. of the Second Entomological Congress, pp. 78-89 (avec la
bibliographie compléte relative aux puerulus).
1913a. Id. The Post-Embryonic Development of the Spiny Lobster.
Nature. Vol. 91, pp. 633, 634 (une figure dans le texte).
1913b. Id. Observations nouvelles sur le développement larvaire de la
Langouste commune (Palinurus vulgaris Latr.). Comptes rendus
Ac. des Sciences. T. 140, pp. 457-463 (avec une figure dans le
texte).
* Les puerulus capturés par M. le Dr. Jousseaume mesurent de 15 4 19 mm, et les
jeunes Langoustes 18 a 20.
DEVELOPPEMENT POST-EMBRYONNAIRE DE LA LANGOUSTE. 193
1913c. Id. La Langouste royale. La Science et la Vie. No. 9, pp. 310-320.
1909.
1863
1858.
1857.
1858.
1892.
1870.
1858.
1858.
1897.
1850.
1873.
(avec figures dans le texte).
Catman, W. T. The genus Puerulus Ortmann and the Post-larval
Development of the Spiny Lobsters (Palinuridae). Ann. and Mag.
Nat. Hist. (8), Vol. 8, pp. 441-446.
. CLraus, C. Ueber einige Schizopoden und niedere Malakostraken
Messina’s. Zeit. Wiss. Zool., B. XIII, pp. 422-433. Taf. XXV,
XXVI.
Coucn, J. Note on the Occurrence of Phyllosoma commune on the
Coast of Cornwall. Journ. of the Proc. Linn. Soc., Zool., Vol. II,
pp. 146-149 (avec figures dans le texte).
Coucu, R. Q. On the Embryo State of Palinurus vulgaris. Rep.
Brit. Assoc. Advance. of Science, 1857, pp. 102-103.
Id. On the Embryo State of Palinurus vulgaris. Nat. Hist. Review,
Vol. IV, pp. 250-251. Pl. XVIII.
CunnincuamM, J. T. On the Development of Palinurus vulgaris, the
Rock Lobster or Sea-Crayfish. Journ. Mar. Biol. Association,
Vol. II. (N.S.), pp. 141-150, Plates VIII et IX. 1891-92 (excellent
exposé bibliographique relatif aux phyllosomes).
Dourn, A. Untersuchungen iiber Bau und Entwicklung der Arthro-
poden. VI. Zur Entwicklungsgeschichte der Panzerkrebse,
Decapoda loricata. Zeit. Wiss. Zool., B. XX, pp. 248-271, Taf.
XVI.
GERBE, Z.,in COSTE. Note sur la larve des Langoustes. Comptes
rendus Ac. des Sciences. T. 46, pp. 547-548, et Rev. et Mag.
de Zool. (2). T. X, pp. 134-136.
GuERIN-MENEVILLE, F. E. Phyllosome ... premier état des
Langoustes. Soc. ent. de France (3). T. VI. Bulletin, pp. xliv—
xlv.
Ortmann, A. E. Ona New Species of the Palinurid genus Linuparus,
found in the Upper Cretaceous of Dakota. Am. Journ. of Science.
Vol. IV, p. 290 (note).
Remnuarpt, F. Phyllamphion en ny Slaegt af Stomatopodernes
Orden. Vid. Medd. Naturh. For. 1849-1850, pp, 2-6, et 1858,
Dab sh. (A):
Ricuters, Ferd. Die Phyllosomen, ein Beitrag zur Entwicklungs-
geschichte der Loricaten. Zeit. Wiss. Zool., B. XXIII, pp. 621-
646, Taf. XXXI-XXXIV.
[ 194 ]
Observations nouvelles sur les trachelifer, larves
luciferiformes de Jaxea nocturna.
Par
M. E.-L. Bouvier,
Professeur au Muséum @ Histoire Naturelle, Paris.
Avec 11 Figures dans le texte.
DuRANT mon. premier séjour au Laboratoire de Biologie maritime de
Plymouth, en qualité de ‘first Ray Lankester Investigator,” j’ai eu
la bonne fortune de trouver un certain nombre d’exemplaires de la trés
curieuse forme larvaire découverte en Ecosse, prés d’ Arran, par G. Brook
(1889) qui lui donna le nom de trachelifer. Ces exemplaires furent
captures au filet Petersen par l’Ozthona, bateau du Laboratoire, entre
Fic. 1—Trachelifer au stade mysis imparfaite ; longueur 9 mm.
Looe et Eddystone, le 13 aofiit 1913. Ils appartiennent sans conteste a
la forme méme décrite par Brook et, comme eux, présentent les traits
suivants qui sont fort caractéristiques (Fig. 1); un corps étroit, allongé
tout a fait identique a celui des Crustacés décapodes du genre Lucifer ;
—des yeux volumineux et courts entre lesquels fait saillir une petite
pointe rostrale ;—des mandibules en forme de long crochet recourbé—
une paire de crochets épiméraux sur le bord postérieur des segments 2 4 6
de abdomen ;—enfin un telson élargi en arriére et muni de soies sur son
bord postérieur largement échancré. Brook n’a pas eu de peine 4 montrer
que cette larve ne ressemble aux Lucifer que par sa forme et qu’elle s’en
OBSERVATIONS NOUVELLES SUR LES TRACHELIFER, 195
distingue par tous les traits essentiels ; mais il ne se crut pas en mesure
d’émettre une opinion définitive sur ses affinités, d’autant que ses
matériaux se limitaient 4 des individus relativement jeunes, les plus petits
mesurant 6 mm. de longeur, les plus grands 9.
Au surplus, quelques années avant l’observation de Brook, la méme
larve avait été découverte dans |’Adriatique par Claus qui, sans lui
donner un nom spécial, en fit d’abord (1884, 32) connaitre deux stades
jeunes, l’un de 4 mm. 5, l’autre de 7 mm. 5, puis (1885, 63-64) un stade
beaucoup plus avancé (12 4 15 mm.), ce qui lui permit de regarder cette
larve comme celled’un rare Thalassinidé méditerranéen, la Jaxea nocturna,
Nardo-Chiereghin (=Calliaxis adriatica Heller).
Depuis, dans un travail fort intéressant au point de vue bibliographique,
M. T. Scott (1898, 268-269) rapporte qu’il a capturé le trachelifer dans
le Golfe de Clyde et a étudié particuliérement un stade avancé dont le
longueur atteint 16mm. 5. La méme larve a été retrouvée en abondance
par ce zoologiste 4 Tobermory, détroit de Mull (1901, 481), et par son fils,
M. A. Scott (T. Scott, 1901, 481) dans le Barrow Channel, prés de Barrow-
in-Furness, puis plus récemment (1905) dans les mers d’Irlande. Enfin
cette larve, au stade le plus jeune, avait été recueillie en Méditerranée
et décrite par M. G. Cano, qui en a donné une figuration (1891) ;
d’aprés A. M. Norman et T. Scott elle aurait également été prise (1906, 13)
par M. Robert Gurney au large de Salcombe, c’est-a-dire dans les eaux
mémes de la région de Plymouth.
Je dois ajouter, pour étre complet, que M. T. Scott (1900, 405) a regu
des restes de la forme adulte trouvés dans l’estomac du Rouget ou
“ ournard ” (Trigla gurnardus L.) et du Pleuronectes cynoglossus, L., dans
le Golfe de Clyde ; si bien qu’on doit croire, avec M. Scott, que la forme
adulte habite réellement les eaux anglaises.
La se bornent, &4 ma connaissance, les observations relatives a la
curieuse larve ; comme elles sont fragmentaires et éparses, j’ai cru bon
de les réunir en les augmentant de celles que j’ai pu faire au laboratoire
de Plymouth sur les quelques exemplaires capturés par l’Ovthona.
Stades larvaires actuellement connus.—A tous les stades actuellement
connus, le trachelifer est franchement lucifériforme, ce qui le distingue
nettement des Lucifer qui n’atteignent leur forme spéciale qu’a l'état
de jeune immature, ainsi qu’il résulte des belles observations de M. W.-K.
Brooks.*
Longueur 4 mm. (1% stade larvaire, zoé).—Ce stade a été décrit et par-
* W. K. Brooks. ‘‘ Lucifer: a Study in Morphology” (Philosoph. Transactions,
Vol. 173, p. 57-187, 11 Planches, 1883).
NEW SERIES.—VOL. x. NO. 2. JUNE, 1914. N
196 M. E.-L. BOUVIER.
ticuliérement figuré par Claus (1884, 32, Figs. 48-50). Ses appendices
buccaux sont développés, avec la mandibule gauche et le paragnathe
en long crochet courbé, caractére tout a fait propre a cette larve et qui
persiste & tous les stades ; la mandibule droite est normale ; les appen-
dices thoraciques se réduisent aux deux paires de maxillipédes antérieurs
qui sont biramés et fonctionnels, du moins au point de vue de la natation.
Le telson est élargi en arriére et trés profondément échancré, beaucoup
plus que dans les autres stades; il ne porte qu’un petit nombre de
soles.
Longueur 6 mm. (zoé).—Stade étudié et figuré par Brook (1889, 420,
Fig. 1). Les pédoncules antennulaires paraissent indivises et le fouet qui
les termine est remarquablement court; les antennes présentent une
épine basilaire et deux branches subégales dont l’externe porte des soies
et n’atteint pas l’extrémité distale des pédoncules antennulaires. Les
mandibules conservent les traits du stade précédent; les deux paires
de machoires sont biramées. La troisiéme paire de maxillipédes ap-
parait sous la forme d’un bourgeon simple, comme d/ailleurs les péréio-
podes des deux premiéres paires. Les autres appendices ne sont pas
encore développés et aucune ligne articulaire ne sépare le telson du
dernier seement abdominal.
Lonqueur 7 mm. 5 (z0é).—Stade étudié par Claus (1884, 32). Les
trois paires de maxillipédes sont biramés et fonctionnels ; les péréiopodes
sont tous représentés par des bourgeons.
Un stade un peu plus avancé a été décrit par Brook (1889, 420-421) :
les péréiopodes antérieurs s’allongent en acquérant un exopodite fonc-
tionnel; les uropodes apparaissent 4 la base du telson qui est séparé
du 6¢ segment abdominal. Les péréiopodes des deux paires postérieures
ne seraient pas encore développés ce qui ne concorde guére avec les
observations de Claus et semble pour le moins douteux. Ce stade est
intermédiare entre la zoé et la mysis.
Longueur 9 mm. environ—(mysis imparfaite). C’est le dernier stade
ésudié par Brook et celui auquel appartiennent la plupart des exem-
plaires de VOithona; les caractéres schizopodiens sont indiqués
par la division en exopodite et endopodite des six paires d’appendices
thoraciques antérieurs, mais le stade mysis n’est pas encore complete-
ment réalisé, car les exopodites des cing paires antérieures fonctionnent
seuls comme rames natatoires. I] convient de décrire ce stade dont
Brook n’a fait qu’une étude incomplete (1889, 421, Fig. 2).
Les antennules (Figs. 1 et 2) sont longuement pédonculées mais les.
trois articles de leur pédoncule semblent peu distincts ; elles se termiment
OBSERVATIONS NOUVELLES SUR LES TRACHELIFER. 197
par deux courts fouets simples, l’un externe assez fort, l’autre interne
plus long et plus gréle. I] y a de longues soies sur la face dorsale des
pédoncules et a Vextrémité distale du fouet externe. Les antennes
(Figs. 1 et 2) n’atteignent pas l’extrémité des pédoncules antennulaires ;
leur second article présente une pointe antéro-externe et porte a son
sommet deux longues branches subégales, simples l’une et l’autre: un
exopodite ou écaille, longuement sétifére, un endopodite un peu plus long
et dépourvu de soies.
Les appendices buccaux sont, comme dans le genre Lucifer, situés
fort loin des yeux, juste derriére l’étranglement quisépare du thorax la
trés longue et fort gréle région céphalique (Fig. 1), ils comprennent des
ma ma! arate
Fig. 2. Fig. 3.
ey
Ss
Fic. 2.—Trachelifer de la Fig 1: yeux, antennes et antennules vus du coté dorsal.
Fic. 3.—Trachelifer de la Fig. 1: une mandibule (md), une maxille (mx!), et une
machoire (mx?),
mandibules, des maxilles, et des machoires (Fig. 3). Les paragnathes et
mandibules (md) présentent toujours la forme curieuse signalée par
Claus dans les exemplaires du premier stade, a savoir celle d’un crochet
longuement recourbé. Je n’y ai pas vu de palpe. L’un des crochets m’a
paru simple, autre était finement denticulé vers le bout distal. Les
mazilles (mx) sont trés normales avec un palpe simple muni au sommet
de trois soies et une lacinie bien développée mais pauvrement sétifére ;
Je n’y al pas vu de lame exopodiale. Les méchotres (mx?) ont également
une structure normale ; leurs lacinies externe et interne sont armées de
soles, mais indivises; leur palpe est court, leur exopodite cilié. Je n’ai
pu observer la partie postérieure de cette lame exopodiale.
Les appendices thoraciques (Figs. 1, 4, et 5) sont au nombre de huit
paires. Les deux paires antérieures (Fig. 4, maxillipédes 1 et 2) se différen-
cient de toutes les autres (Fig. 5) en ce sens que V’article basilaire de leur
exopodite est fusionné completement avec Varticle basal de Vendopodite,
198 M. E.-L. BOUVIER.
d’ot il résulte que la partie libre de l’exopodite se compose seulement de
deux articles et la partie libre de l’endopodite de quatre; le dernier
article de l’exopodite se termine par six longues soies bipennées; on
Fic. 4.—Trachelifer de la Fig. 1: maxillipédes de la 1'¢ (mxp!) et de la 2° paires (mxp?)
trouve également des soies sur les divers articles de l’endopodite (Fig. 4).
Les appendices des quatre paires suivantes (Fig. 5, mxp.*, p.t, p.?, p.%)
sont biramés comme ceux qui précédent, mais sans fusion basale de
V exopodite et de endopodite ; si bien que, dans ces appendices, l’exopodite
3 f 2 3
Te ae p
Fic. 5.—Trachelifer de la Fig. 1: maxillipéde postérieur et les cinq péréiopodes du
méme cété (p! a p?).
se compose de trois articles libres. Au surplus, l’exopodite n’est sétifére
et fonctionnel que dans les trois paires antérieures (maxillipédes 3,
péréiopodes 1 et 2), il se réduit a l’état de bourgeon dans ceux de la
derniére paire (6¢ paire thoracique representant les péréiopodes 3) comme
d’ailleurs endopodite des quatre paires qui nous occupent. J’ajoute
OBSERVATIONS NOUVELLES SUR LES TRACHELIFER. 199
que ces bourgeons endopodiaux sont simples (Fig. 5), sans articulation
apparente, toujours dépourvus de soies, trés courts dans les appendices
antérieurs, plus allongés en arriére ot ils atteignent a peu prés les dimen-
sions de l’exopodite. Les appendices des deux paires postérieures (péréio-
podes 4 et 5) sont réduits a Vétat de bourgeons simples, privés de soies et
non fonctionnels, ceux de la derniére paire étant un peu plus courts
que les précédents (Fig. 5, p.4, p.®).
Ainsi le thorax des larves 4 ce stade porte six paires d’appendices
biramés dont la sixiéme n’est pas fonctionelle et dont les deux premiéres
se différencient de toutes les autres par la fusion basale de leurs exopodites
et endopodites qui sont l'un et l’autre fonctionnels; 4 partir de la
troisiéme paire, les endopodites se présentent sous la forme de bourgeons
non fonctionnels, comme les appendices des deux derniéres paires qui,
d’ailleurs, ne sont pas birames.
Fig. 6. Fig. 7.
Fic. 6.—Trachelifer de la Fig. 1: le 7° segment abdominal avec ses épines postérieures et
ses bourgeons pléopodiaux,.
Fic. 7.—Trachelifer de la Fig. 1: dernier segment abdominal, telson et uropode gauche.
Cette description des appendices thoraciques différe beaucoup de celle
qu’a donnée Brook ; car mon regretté prédécesseur n’a signalé ni la bifur-
cation des péréiopodes, ni la curieuse particularité des deux paires de
maxillipédes antérieures. Et ces deux caractéres sont, 4 coup sir, les
plus importants dans la forme que nous étudions. J’ajoute que Brook
mentionne simplement, sans les décrire, les maxilles et les mAchoires.
L’abdomen (Figs. 1, 6, 7) présente les caractéres signalés par Brook,
avec de longues pointes épimérales (nulles sur le premier segment, par-
ticuliérement longues sur le sixiéme) et un telson trés élargi en arriére
ott il présente 11 ou 12 paires de soies spiniformes (Fig. 7). La caractéris-
tique du stade dont nous faisons l'étude, c’est apparition des uropodes
(Fig. 7) qui se composent de deux lames sétiféres subégales beaucoup
plus courtes que le telson. Les pléopodes font défaut ou, dans quelques
cas trés rares, apparaissent sous la forme d’un trés court bourgeon
(Fig. 6).
200 M. E.-L. BOUVIER.
Longueur 10 d@ 11 mm. (mysis)—Un exemplaire capturé par |’Ov-
thona différe des précédents en ce sens que les exopodites des appendices
thoraciques de la €¢ paire (péréiopodes 3) sont fonctionnels et que l’endo-
podite des péréiopodes de la paire antérieure commence a se fendre
pour produire la pince (Fig. 8). C’est le stade mysis proprement dit.
Longueur 13 mm. (stade mysis a chélipédes).—Ce stade n’a pas été
signalé jusqu ici; il est représenté dans les récoltes de /Ovthona par
un seul individu. Cet exemplaire ressemble tout a fait a ceux qui précé-
dent par la structure du corps, mais il s’en distingue par les caractéres
suivants, dont certains ont une grande importance.
Les pédoncules antennulaires sont fort nettement triarticulés; les
antennes présentent une épine antéro-inférieure sur chacun de leurs deux
Fic. 8.—Trachelifer au stade mysis, long de 10mm.: un péréiopode antérieur avec
V’endopodite commencant a se transformer en pince.
articles basilaires, leur endopodite se différencie en une hampe basale et
un fouet ; ce dernier dépasse notablement les antennules mais n’est pas
encore brisé en articles.
Les pléopodes abdominaux se développent sur les segments 2 a 5 sous
la forme de bourgeons allongés et bifurqués (Fig. 8). Les rames des
uropodes restent subégales, et dépassent notablement le milieu du
telson. L’échancrure terminale de celui-ci est limitée en avant par un
bord presque rectiligne et sur les c6tés par les deux pointes normales, qui
sont divergentes et presque droites.
Les appendices buccaux et les yeux ne présentent rien de particulier ;
les appendices thoraciques sont en méme nombre qu’au stade précédent,
de méme type, et doués des mémes fonctions, les appendices de la €e
paire (péréiopodes 3) étant semblables aux précédents en ce sens que
leur exopodite est sétifére et fonctionnel (Fig. 9 et p.3, Fig. 11). I] faut
signaler & ce stade le développement d’un trés court bourgeon exopodial
OBSERVATIONS NOUVELLES SUR LES TRACHELIFER. 201
(Fig. 9 et p.4, Fig. 11) & la base des appendices de la paire suivante
(peré-opodes 4); la présence de cet exopodite rudimentaire montre qu’il
faut considérer comme un endopodite les appendices assez réduits et
trés vaguement articulés qui représentent les deux derniéres paires de
péréiopodes (Fig. 8 et p.4, p.5, Fig. 11).
Mais ce qui distingue surtout notre exemplaire et lui donne une signifi-
cation importante, c’est la structure des appendices de la 4¢ paire (Fig. 9
et p.t, Fig. 11) qui réprésentent, comme on sait la paire antérieure
des péréiopodes des Crustacés décapodes ; dans cette paire, V endopodite
se termine par une pince bien formée et présente des lignes articulaires
assez nettes; d’ailleurs les deux pinces sont égales et semblables, trés
Fic. 9.—Trachelifer au stade mysis & chélipédes (long. 13 mm.): thorax avec un
appendice et partie antérieure de l’abdomen.
développées et a peu prés aussi longues que le reste de l’endopodite ;
leurs doigts ont a peu prés la méme longueur que le reste de la portion
palmaire et laissent entre eux un léger hiatus.
J’ajoute qu’on observe des bourgeons branchiaux sur tous les appen-
dices thoraciques, depuis la deuxiéme paire jusqu’a la septiéme (Figs. 10
et 11).
Longueur 15 4 16 mm. (dernier stade mysis). Je n’ai pas eu d’exem-
plaires a ce stade quia été étudié par Claus (1885, 63-64, Taf. V., Fig. 45)
avec le plus grand soin, du moins en ce qui regarde la région thoracique.
C’est un stade mysis, comme les deux précédents.
Ce stade différe de celui que je viens de décrire par la segmentation
trés nette des appendices thoraciques, par la réduction plus grande des
202 M. E.-L. BOUVIER.
deux paires postérieures de péréiopodes, et par l’allongement de l’exo-
podite des péréiopodes 4 qui restent non fonctionnels, enfin et surtout
par ses branchies qui sont en méme nombre que dans les Jawea et déja
divisées en lamelles branchiales.
Je crois bien qu'il faut rapporter a ce stade l’exemplaire de 16 mm.
briévement décrit et figuré par M. T. Scott (1898, 269, Pl. 12, Figs. 16-20).
A vrai dire, M. Scott ne mentionne pas les branchies mais l’examen qu'il
fit de son exemplaire fut certainement trés rapide, si j’en juge d’aprés
les Figures 19 et 16 du travail, qui sont défectueuses.
Conclusions.—M. Scott rappelle, dans son intéressante note, tous les
travaux relatifs 4 la curieuse larve que nous venons d’étudier. Son
maze
Fic. 10.—Trachelifer de la Fig. 9: les maxillipedes des deux premieres paires.
travail, 4 ce point de vue, offre au vif intérét, et je dois remercier mon
excellent collégue M. Calman qui, par l’intermédiaire de M. Allen, a eu
Vobligeance de me le faire connaitre. Sans cet avis précieux, je me serais
borné peut-étre a faire une comparaison entre les stades que j’ai décrits
et ceux observés par Brook, alors que cet auteur n’a pas reconnu les
affinités de sa larve trachelifer et qu'il ignorait, non seulement le travail
ou Claus a pour la premiére fois signalé cette larve (1884), mais en outre
celui ott l’éminent zoologiste de Vienne donna une exacte signification
de sa découverte (1885). Or, cette derniére étude est de grande impor-
tance: Claus a observé, en effet, que la bizarre larve capturée a Trieste
présente, en dépit de sa forme, tous les caractéres essentiels des larves des
Thalassinidés, qu’elle ressemble tout a fait, par ses caractéres, aux
OBSERVATIONS NOUVELLES SUR LES TRACHELIFER. 203
larves de Gebia littoralis Risso supérieurement étudiées par M. G. O. Sars,*
quelle posséde le méme nombre de branchies que le Calloaxis adriatica
et qu il faut la considérer comme la forme larvaire de ce Thalassinien.
Cette identification ne saurait faire le moindre doute;f elle peut
méme étre poussée jusqu’au détail, car dans les figures données par
M. G. O. Sars, on voit que les exopodites des maxillipédes des deux
paires antérieures se distinguent des autres par la fusion de leur article
basal avec le deuxiéme article de endopodite. Nous avons montré plus
haut qu il en est de méme dans le ¢rachelifer. J’ajoute, comme Claus
la d’ailleurs observé, que les trachelifer au stade mysis avancé sont
dépourvus de pléopodes sur le segment abdominal antérieur et que leurs
péréiopodes des deux derniéres paires restent a l’état de bourgeons non
fonctionnels, deux caractéres également propres aux mysis de Gebia.
y
xp
Fic. 11.—Trachelifer de la Fig. 9: maxillipede postérieur et les cing péréiopodes du
méme cote.
M. G. O. Sars signale cing stades larvaires dans le développement de
la Gebia littoralis ; 1°, au premier stade, qui est celui de zoé, les deux
paires antérieures de maxillipédes sont fonctionnelles, et l’on observe
les bourgeons, parfois bifurqués, de presque tous les appendices thora-
ciques suivants, sauf ceux de la derniére paire; 2°, la deuxiéme forme
larvaire tient le milieu entre la zoé et la mysis; tous les appendices
thoraciques sont développés et tous, sauf ceux des deux derniéres paires,
ont une branche endopodiale et une branche exopodiale, mais cette
derniére n’est fonctionnelle que dans les quatre paires antérieures (les
* G. O. Sars. ‘‘ Bidrag til Kundskab on Decapodernes Forvandlinger. I. Nephrops,
Calocaris, Gebia” (Arch. for Math. og Naturvid., B. 1X, pp. 155-204, Pls. 1-7, 1884).
+ Elle est d’ailleurs acceptée par M. M. Korschelt et Heider qui ont identifié (1892,
471) le trachelifer avec la larve de Claus, par M. Scott (1899, 69) et par M. Calman
(1909, 301).
204 M. E.-L. BOUVIER.
trois paires de maxillipédes et les péréiopodes 1); 3°, la troisiéme forme
larvaire correspond au stade mysis, mais c’est une mysis dépourvue
d’exopodites sur les péréiopodes des deux derniéres paires, les exopodites
des autres appendices thoraciques étant d’ailleurs fonctionnels; il y a
des bourgeons de pléopodes, le telson est séparé du 6% segment abdominal
qui porte en arriére des uropodes biramés; 4°, au dernier stade larvaire,
la structure est a peu prés identique, mais les pinces commencent a
présenter une échancrure digitale et les pléopodes sont allongés avec
une seule branche. Au stade suivant, la forme Gebia est réalisée.
Tels sont les quatre stades larvaires indiqués par M. G. O. Sars; on
doit les considérer comme des stades essentiels reliés entre eux par des
intermédiaires qui se manifestent a la suite de mues. Du moins en est il
ainsi dans notre ¢rachelifer :—les trois premiéres formes décrites plus
haut (4 a 7 mm.) dans cette larve sont des zoés a divers stades, les plus
simples sans appendices thoraciques autres que les maxillipédes des deux
paires antérieures, les plus avancés ayant les caractéres des larves de
Gebia au 2¢ stade, mais en plus les péréiopodes postérieurs et des uropodes
biramés :—la forme suivante (9 mm.) est une myszs imparfaite qui n’est
pas encore au stade 3 de la Gebza, car les exopodites des péréiopodes y sont
a Pétat de bourgeons non fonctionnels; il est probable qu'une simple
mue suffit pour que ces bourgeons deviennent natatoires, et que la mysis
parfaite des Thalassiniens soit réalisée ;—a la mysis typique font suite,
dans le trachelifer, trois stades mysidiens successifs (10 a 16 mm.) ctl
les péréiopodes antérieurs se terminent par des pinces de plus en plus
parfaites, ou les branchies sont de plus en plus développées, et ot les
pléopodes acquiérent progressivement leurs deux rames, le premier de
ces stades mysidiens a pinces correspond a trés peu prés au 4° stade
larvaire décrit par Sars dans la Gebia littoralis.
Ainsi, Claus avait amplement raison de regarder la forme larvaire qui
nous occupe comme une larve de Thalassinidé, et sans doute aussi
avait-il raison de voir dans cette forme curieuse la larve de la Jazea
nocturna ; elle ne saurait étre rapportée, en effet, aux autres Thalas-
sinidés méditerranéens qui tous ont une forme larvaire plus differente
de celle des Gebia ; et d’autre part, Claus observe qu’a un stade avancé
elle présente les mémes branchies que la Jaxed*nocturna.
Faut-il croire, avec Claus, qu’une mue devra suffire pour conduire de
cette larve lucifériforme avancée a lindividu présentant les caractéres
de l’adulte ? J’ai sous les yeux deux exemplaires de Calliaxis adriatica
envoyés jadis au Muséum par Heller; ils sont tout a fait d’un type
astacien et si différents du trachelifer qu’on pourrait mettre en doute la
OBSERVATIONS NOUVELLES SUR LES TRACHELIFER. 205
possibilité d’un passage direct de l'un a Vautre. Dans les Thalassinidés
comme chez les Paguriens et les Macroures marcheurs cuirassés
(Palinuridés, Scyllaridés), un stade intermédiaire doit rattacher la
forme adulte a la forme mysidienne, un stade natant (pour me servir d’une
terme fort juste emprunté 4 M. Boas) ot la forme se rapproche déja
beaucoup de celle de l’adulte, et cui la natation s’effectue au moyen des
pléopodes dont l’appendice interne présente des rétinacles. Le jeune de
Gebia littoralis figuré par M.G. O. Sars (1884, Taf. V, Fig. 1) est certaine-
ment a ce stade intermédiaire, il mesure environ 6 mm.
Le stade natant de la Javea nocturna peut-étre imaginé un peu plus
long et plus gréle, parce que l’adulte différe de la Gebia littoralis au point
de vue de la gracilité du corps; par une contraction et une condensation
analogues a celles qui se produisent dans le phyllosome passant au pueru-
lus, le trachelifer lucifériforme long de 15 a 16 mm. donnera un natant
plus court de moitié et présentant déja la forme des Jaxées adultes.
Cette forme, d’ailleurs, sera aisément reconnaissable a ses pinces
astaciennes, qui sont déja fort longues dans les mysis et qui le sont plus
encore chez l’adulte. Ainsi le petit organisme sera aisé a reconnaitre et
on le trouvera sans doute quelque jour dans les péches pélagiques au
filet fin.
C’est une capture que l’on peut faire a Plymouth, dans les parages
de Looe—Eddystone ct l’Ozthona fit Vheureuse trouvaille des exem-
plaires étudiés dans le présent opuscule. La également devra-t-on
rechercher la forme adulte, Jaxea nocturna, mais alors au moyen de
péches effectués sur le fond, au chalut plutdt qu’a la drague. Cette
derniére recherche sera certainement bien plus difficile que la premiere,
car la Jaxée adulte est un animal rarissime, trouvé seulement a Trieste,
puis & Naples ot d’aprés 8. Lo Bianco (1898-99, 503) on n’en put prendre
qu’un exemplaire au cours de 25 ans.*
Voila pour les travailleurs du Laboratoire de Plymouth, un sujet de
recherches tout indiqué. Grice au concours de tout le personnel du
Laboratoire, surtout au zéle obligeant de M. le Directeur Allen et de
M. Clark, on sait aujourd’hui que la Jazxea nociurna, déja connue a Sal-
combe sous la forme de larve, habite aussi le voisinage immédiat de
Plymouth. II n’y a pas lieu de douter qu’on trouvera quelque jour,
dans les mémes eaux, le stade natant inconnu et l’adulte de cette espéce.
* Cet exemplaire fut capturé non loin de Ja station zoologique, par 15 metres de
profondeur, sur fond de vase et sable fin.
206
1899:
1900.
1902.
M. E.-L. BOUVIER.
INDEX BIBLIOGRAPHIQUE.
G. Broox. Notes on a Lucifer-like Decapod Larva from the West
Coast of Scotland. (Proc. Royal Soc. Edinburgh, Vol. XV,
pp. 420-423, Figs. 1 and 2, 1889.)
W. T. Catman. Appendiculata. Third fascicule. Crustacea, p. 301.
(Treatise on Zoology, publié sous la direction de Ray Lankester.)
G. Cano. Sviluppo postembryonale della Gebia, Axius, Callian-
assa, e Calliaxia. (Boll. Soc. Natur. Napoli, Vol. V, p. 12, Pl. 4,
Figs. 1-13, 1891.)
C. Craus. Zur Kentniss der Kreislaufsorgane der Schizopoden und
Decapoden. (Arb. Zool. Inst. Wien, B. V, p. 32, Taf. VIII,
Figs. 48-50, 1884.)
Ip. Neue Beitrige zur Morphologie der Crustaceen (Id., B. VI,
pp. 63-64, Taf. V, Fig. 45, 1885.)
E. Korscuett und K. Herper. Lehrbuch der vergleichenden
Entwicklungsgeschichte der wirbelloser Thiere. Specieller
Theil, p. 471.
S. Lo Branco. Notizie biologiche riguardente specialemente il
-periodo di maturata sessuale degli animali del Golfo di Napoli.
(Mitth. Zool. Station Neapel, B. XIII. p. 503, 1898-99.)
A. M. Norman and T. Scorr. The Crustacea of Devon and Cornwall,
pp. 12-13, 1906. (Avec toute la bibliographie de l’espece.)
A. Scorr. On the Tow-nettings collected in the Irish Sea. (Proc.
Liverpool Biol. Soc., T. XTX, pp. 196-205 ).
T. Scorr. Notes on the Recent Gatherings of Microcrustacea from
the Clyde and the Moray Firth. (Annual Report Fishery Board
of Scotland, 1898, Part III, pp. 268-269, Pl. 12, Figs. 16-20, 1899.)
Ip. Notes on some Gatherings of Crustacea collected for the most
part on board the Fishery steamer Garland, and examined
during the past year (1899). (Highteenth Annual Report Fishery
Board of Scotland, for the year 1899, pp. 405-406, 1900.)
Ip. Notes on Gatherings of Crustacea collected by the Fishery
steamer Garland and the Steam trawlers Star of Peace and
Star of Hope, of Aberdeen, during the year 1901. (Twentieth
Annual Report Fishery Board of Scotland, for the year 1901,
p. 481, 1902.)
207%]
Quelques mots sur la variabilité du Pycnogonum
littorale, Strom.
Par
M. E.-L. Bouvier,
Professeur au Muséum @ Histoire naturelle, Paris.
. >]
Avec 2 figures dans le texte.
DuRANT mon séjour au Laboratoire de Biologie maritime de Plymouth,
j'aieu l’occasion d’examiner un lot trés important de Pycnogonum littorale,
Strém, qui se trouvait dans les collections de l’établissement depuis
le 8 juillet 1908. Ce lot ne comprenait pas moins de 3268 individus.
Il avait été recueilli au Barbican Pool, vieux port de Plymouth, dans les
filets de pécheurs qui avaient fait leur capture, disaient-ils, 4 200 milles
O. N. O. des Iles Scilly. Les exemplaires étaient beaucoup plus nom-
breux, mais le Laboratoire: n’avait pas cru devoir en conserver
davantage.
Je ne crois pas qu’on ait signalé jusqwici une pareille abondance des
Pycnogonides de cette sorte; évidemment l’espéce devait pulluler aux
lieux ot elle fut prise. C’est le premier point sur lequel il me semble
utile d’attirer l’attention.
J’ai voulu profiter de cette péche miraculeuse pour mettre en lumiére
quelques autres faits relatifs & Vhistoire du dit Pycnogonum.
J’ai constaté tout d’abord que l’espéce atteignait, au point ot elle
fut prise, des dimensions plutdt fortes; les femelles mesuraient en
moyenne 13 mm. du bout de la trompe a l’extrémité posterieure de
l'abdomen; les males 11 mm. au plus. Les males sont a peu pres de
moitié moins nombreux que les femelles: ces derniéres étaient repré-
sentées dans la collection par 2082 individus; les males par 1186. Sur
ce nombre 185 seulement étaient porteurs de masses ovigeres.
Ces observations peuvent avoir un léger intérét mais ce nest point
pour les faire que j’ai passé en revue, successivement, tous les exemplaires
capturés ; je voulais profiter de la récolte pour étudier les variations du
Pycnogonum littorale en un méme lieu, surtout espérant trouver, dans
208 M. E.-L. BOUVIER.
cette abondante récolte, un individu anormal quant au nombre des
pattes. Mon espoir a été complétement dégu: Vespéce est remarquable
par la fixité de ses caractéres, les seules variations qu’on y observe
sont trés légéres et relatives a l’inflexion plus ou moins grands de la
trompe, au pigment des yeux, au développement des tubercules
dorsaux.
Tous les exemplaires avaient le nombre normal d’appendices; tous, sauf
un seul (Fig. 1), surlequel je croisutile d’attirer attention. Cetexemplaire
est une grande femelle trés asymétrique présentant quatre pattes du
Fic. 1.—Femelle anormale de Pyenogonwm Littorale ; vue du cété dorsal et grossie 2 fois.
coté droit et trois du cé6té gauche: la derniére patte droite (Fig. 2, p.*)
est dirigée en arriére suivant l’axe du corps avec un trés gros tubercule
dorsal sur son article basilaire ; l’abdomen (ab.), faiblement dilaté en
arriére, est rejeté obliquement du cdté gauche entre la patte préecédente
(p.4) et la derniére, ou troisiéme (p.*) du cété gauche. Cette anomalie
bizarre me parait due a l’ablation accidentelle de la quatriéme patte
gauche, non pas chez l’adulte, mais chez l’individu trés jeune, alors que
les pattes de la quatriéme paire étaient encore a ]’état de fréles bourgeons ;
car on ne voit plus traces, dans l’exemplaire, de la patte perdue.* Ainsi
* La disparition de la 4° patte gauche a eu pour résultat de faire disparaitre l’orifice
sexuel correspondant ; notre exemplaire ne posséde qu'un orifice sexuel, celui du coté
droit (09).
QUELQUES MOTS SUR LA VARIABILITE DU PYCNOGONUM LITTORALE. 209
un espace serait devenu libre en arriére du cété gauche, et aurait été
occupé par abdomen et la derniére patte droite.
I] résulte des observations précédentes que le nombre des pattes est
absolument constant dans notre Pycnogonum. Comme ces appendices
se développent successivement d’avant en arriére, il semblerait possible
qu’anormalement une cinquiéme paire ptt prendre naissance et, plus
possible encore, que la quatriéme paire ne se produisit pas. Ces deux
anomalies pourraient étre interprétées comme le premier pas vers des
formes nouvelles qui, dans le premier cas, seraient décapodes, et dans
le second, simplement hexapodes. Mais elles ne semblent pas pouvoir
se produire et, comme on connait d’ailleurs trois genres de Pycnogonides
w)
Fic. 2,—Extrémité postérieure tres grossie de la méme femelle ; cote dorsal.
a dix pattes (Decolopoda, Pentanymphon, Pentapycnon) appartenant
aux familles les plus diverses, il semble naturel de considérer la forme
décapode comme une forme ancestrale qui, par réduction dans le nombre
des pattes, a conduit au type actuel du groupe, je veux dire au type
décapode.
Appendices.—Jeviens de recevoir du Laboratoire de Plymouth une petite
collection de Pycnogonum littorale recueillie par le 8.8. Albatross, au large
210 M. E.-L. BOUVIER.
de Bishops (& 200 milles O. par N.), le 8 décembre 1913. Cette collection
comprend 44 exemplaires dont 21 ¢ et 23 @. Le corps des plus grands
mAles (céphalothorax + abdomen) mesure 8 mm., celui des plus petits 7;
la taille des femelles varie entre 10 mm. et 8mm.; dans les femelles de
8 millimétres, l’orifice sexuel apparait fort distinctement, mais ne semble
pas encore fonctionnel. Atnsi, les femelles ott le sexe commence a se
manifester quelque peu extérieurement égalent au moins la taille des
plus grands males. Les males, pour une moitié, sont chargés de pontes
relativement récentes et tous semblent avoir atteint la maturité
sexuelle.
feaite |
On Some Plymouth Holothurians.
By
J. H. Orton, A.R.C.Sc., B.Sc.,
Naturalist at the Plymouth Laboratory.
With 13 Figures in the Text.
TABLE OF CONTENTS.
PART I.
: PAGE
On the specific characters of Cucumaria normani Pace, and Cucumaria saxicola
Brady and Robertson, with an account of some undescribed differential
characters and an investigation of the variation of the gonad in C. saxicola
Comparison of the characters of C. normani and C. saxicola : : : 5 alli
Variation of the gonad of C. saxicola ? : : ; : : : . 214
The gonad of C. normani : : ‘ se QUT
Characters of the calcareous collar af C. sabia and ae OC. normant . : . 219
Characters of the spicules and tube-feet in C. saxicola and C. normani . : . 220
Discussion of some former observations on C. saxicola and C. normani 222
The growth-stages of the bell-shaped spicules of C. normani : . 224
The synonymy of C. saxicola Brady and Robertson and of C. normani Tees . 225
Correlation in the characters of the gonad and ambulacra in the genus Cucwmaria 228
PART II.
On the occurrence of Cucumaria elongata Diib. and Kor. and Thyone raphanus Diib.
and K6r. in the Plymouth District. : : ‘ p : - - 229
Notes on Cucumaria elongata . : . : - é Z - : A all)
On Thyone raphanus Diib. and Kor. - : : ‘ : : ; 5 Ave
PART, 1.
ON THE SPECIFIC CHARACTERS OF CUCUMARIA NORMANI
PACE, AND CUCUMARIA SAXICOLA BRADY AND ROBERT-
SON, WITH AN ACCOUNT OF SOME UNDESCRIBED DIF-
FERENTIAL CHARACTERS AND AN INVESTIGATION OF
THE VARIATION OF THE GONAD IN C. SAXICOLA.
COMPARISON OF THE CHARACTERS OF C. NORMANI AND
C. SAXICOLA.
Some of the specific and differential characters of these two species have
already been enumerated by Pace (1). Subsequently Norman (2)
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914. O
212 J. H. ORTON.
denied that these two forms were different, so that the literature on
them was left in an unsatisfactory state. On investigating these two
forms, however, I have obtained sufficient evidence—from the characters
of the gonadial tubes, the calcareous collars, and the young of both forms
—to verify the observations of Pace and to meet satisfactorily the
objections put forward by Norman against them. The differential
characters of these two species as given by Pace (loc. cit.) have been
verified in an unpublished investigation by Mr. W. De Morgan and by
the present writer. These characters, most of which were observed by
Pace, are now given revised * in the following table in a comparative
manner, so that the differences between these two species can be readily
shown :—
TasLe 1.—A comparison and a contrast of the characters cf C. saxicola
Brady and Robertson and C. normani Pace.
Cucumaria saxicola B. and R.
t+ Common on the shore, also taken
in depths of a few fathoms.
General colour of body a pure
milk white, becoming black when
exposed to light.
Surface of body smooth.
Body wall relatively
thin, marked only with transverse
strize due to encircling fibres of the
delicate,
superficial muscle layer, with rela-
tively few spicules.
General body spicules devoid of
nodulation, lozenge-shaped in one
stage of growth, but subsequently
developing 2 or even 3 additional -
foramina on the ends of the spicule
and thus losing their lozenge shape.
(See 4, Plate LX XII, Fig. 3.)
Cucumaria normani Pace.
+ Fairly common on the shore, also
taken in depths of a few fathoms.
General colour of body dirty
brownish white, black
when exposed to light.
Surface of body much wrinkled.
Body wall tough, coriaceous,
crowded with spicules.
becoming
General body spicules typically
lozenge-shaped, perforated with four
large foramina, and always bearing
on each side about 12 very prominent
nodules. (See 3, Plate XI, Fig. 1.)
* Owing to the fact that both species develop black pigment when and where exposed
to light, it follows that the differential characters depending upon the degree of pig-
mentation of the tentacles and anal aperture noted by Pace cannot be relied upon, and
have consequently been abandoned.
+ As an example for illustrating the occurrence of these two forms, in one day’s
collecting on the shore (3rd April, 1911, Wembury Bay) about 80 C. saxicola were obtained
and only about 6 C, normani, including specimens of various sizes. Another day (Ist May,
1911) about 40 CO. saxicola were obtained and only 2 C. normani. This disproportion is
usual in this district,
ON SOME PLYMOUTH HOLOTHURIANS. 213
Cucumaria saxicola B. and R.
Surface spicules of body irregular
in shape, consisting of rods radiating
from a central portion, scattered in
the skin. (See l.c. above and also
Fig. 6, p. 221.) ,
Podial spicules
typically in a single series.
Fig. 6, p. 221.)
have foramina
(See
Gonadial tubes
varying in number between 10 and
about 60, large, and club-shaped.
(See Fig. 1, p. 214.)
Calcareous collar relatively deli-
cate. Interradial calcareous pieces
deeply bifurcated posteriorly. (See
Fig. 4, p. 218.)
Dorsal ambulacra with modified
tube-feet. (See Fig. 9, p. 228.)
Spawning period about May.
relatively few,
Cucumaria normani Pace.
Surface spicules campanulate,
forming a continuous covering in the
skin of the body. (See Figs. 8 and 7,
pp. 225 and 222.)
Podial spicules have foramina
in two or more parallel rows or with
a group of 3 or 4 small foramina at
each end of the spicule. (See
Fig. 7, p. 222.)
Gonadial tubes very numerous,
frequently more than 500, relatively
small, and of even cylindrical calibre.
(See Fig. 2, p. 214.)
Calcareous collar relatively strong.
Interradial calcareous pieces only
slightly bifurcated posteriorly. (See
Fig. 5, p. 219.)
Dorsal ambulacra with ordinary
ambulatory tube-feet.
Spawning period about March.
The differential characters of most importance in the foregoing table
are (1) those of the main body spicules, (2) the spicules near the surface
of the body, (3) the shape and number of the gonadial tubes, and
(4) the shape and relative stoutness of the pieces of the calcareous collar.
Pace has already emphasized the first and second of these characters.
These have, however, gained additional importance from the recent
observation of their correlation with differences in the gonad and cal-
careous collar. In C. saxicola the gonadial tubes are large, club-shaped,
and few in number (see Fig. 1, p. 214), while those in C. normani are
relatively small, of even, cylindrical calibre, and very numerous, (See
Fig. 2, for the faithful drawing of which I am indebted to Mrs. Orton,
as well as for all the figures by which this paper is illustrated.) The gonad
in the male and female in each of these forms is alike in its structure.
The eggs of both species are about the same size, i.e. about -4 mm. in
diameter, but the sperm has not been examined closely.
214 J. H. ORTON.
VARIATION OF THE GONAD OF CUCUMARIA SAXICOLA.
The variation in the gonad of Cucumarva saxicola has been investigated
in 50 adult specimens varying in size* from about 6 cm. to about 10 cm.
in length. The gonad in adult C. saxicola consists of from about 10 to
60 club-shaped tubes (see Fig. 1, p. 214). These tubes vary in length
Fig. 1. 2s
Fic. 1—The gonad and gonoduct of C. saxicola B. and R. (Drawn in situ, X 3.)
The single tube in the lower part of the figure on the right shows the shape
of the tubes in this species better than those in the upper figure. This tube was
taken from a male gonad, those in the upper figure constitute the whole gonad
of a female.
Fic, 2.—The gonad and gonoduct of C. normani Pace. (Drawn in situ from a female
specimen, x 3.)
from about 1 mm. to about 3-4 cm.: they are narrowest at the attached
end, and vary somewhat in the degree to which the distal end is swollen
(see Fig. 1), but at this part they are commonly 3 mm. in diameter.
In any particular individual the tubes may vary greatly in size. The
* These specimens were all measured when preserved, but as they were mostly well
expanded the measurements may be regarded as roughly comparable.
ON SOME PLYMOUTH HOLOTHURIANS. 215
tubes are arranged to the right and left of the mesentery supporting the
alimentary canal in a position which is just behind the middle of the
length of the animal. In this species the tubes join up at their attached
ends to form a very short duct which unites almost immediately with its
fellow on the opposite side to form the main gonoduct. The number
of tubes on each side of the mesentery was noticed in all the specimens
and recorded in columns 4 and 5 in Table 2 (see p. 215). It was found
that the same number of tubes occurs only rarely on each side of the
mesentery, but that there is generally about the same number: on the
whole, however, more were found on the left than on the right side.
TABLE 2,—Illustrating the variation in the distribution and number of
gonadial tubes in Cucumaria saxicola of different sizes.
Approximate - he nae
ket “Yonah Sex ee
1. 6-0 cm. O* 9 6+1R.7 16
2. 6:0 ,, g tubes full of sperm. 6 11 17
a4. 6:3 d 7 8 15
4. 6-4 ,, 3 6-+1R. 12+3R 22
er GGr tte SD pen. Scr. cote
6. 66... 3d tubes full of sperm. 12+1 R. 812R 23
Ie LOC es 2 tubes up to2-6cm.long. 2+41R. 12+1R 16
8 (68) ee a 14 16 30
9 7-0 -., a 16 15+2 33
10 (aS ase e 12 9 21
ite 10s g tubes full of sperm. 22 V7 39
12. (i wate a 16 7 23
1S: 1:05; é 17+3sm. 13+35sm.7 36
14. TON .; ¢ 8 10 18
15. (ae a 14 8 22
16. Vico hee fo) 4it2 R. 3+1 R. 10
Nie ox + ¢ 12+4 R. 10+3 R. 29
18. Go ae 9 9 9+1R., 19
19. 14-5. Q 10 7 17
20. 14 3: fe) 10+2 R. T+1R. 20
21. i eae fe) 12 12 24
22. ea, d 30+1sm. 30 61
23. (gi ee ¢ 18 iy 29
24. eas. fe) 6 4 10
25. ito) are ft 12 8 20
* Eggs in various stages of development were observed in the tubes of all the females.
7 R. means a rudimentary; sm. a rather small tube.
216 J. H. ORTON.
Approximate
7) On Left Side. Right Side, T°#l
26. 79cm. @ very large tubes. 6-1 FR. 6 13
27. 8-0 ,, 2 8 10 18
28. 8:0 ,, d 8 9 ily
29. 8:0) 3 13 16 29
30. Sans Q 13+1sm. 12+1sm. 27
sii S55. i 6 7 13
o2: Soe 2 13 15 28
So: Saas Q 18 13 26
34. Sas, 3 vi 28 49
35. 8a 2 15 18 33
36. 8:bo, d 29 23 52
oT. Src as Q 7+1 sm. 7+lsm. 16
38. 8-8 ,, ? tubes up to 3-0 cm. long. 13 14 27
BF So" ,, 3 14 15 29
40. 8-8 ,, 2 10 13 23
41. 9:0 ,, d 114+3sm. 11 25
42. 9-0 ,, e 12+12sm. 14+12sm. 50
43. 9:0 ,, ? 12 10 22
44, GO! te d li+Ism. Il 23
4D. 4 ae 2 tubes up to3-4cm. long. 16+1R. 15+1R 33
AG ay LOD: 3 16 21 37
Nice O-O. ? ff 12 19
43? + 10:0: ,, fe) 4 12
As OO... 9 12 8 20
melee BIO:0% 5. a 14 12 26
A glance at the last column of Table 2 shows at once that the variation
in number of the gonadial tubes in this species is distributed sporadically
among individuals, and that the number does not necessarily increase
with the size of the adult animal. Since the number of gonadial tubes
is variable, it is of interest to examine the relative frequencies of the
occurrence of any particular number. The frequencies of particular
numbers, as, for example, of numbers between 10 and 15, and 16 and 20,
and so on, have been plotted to give the curve in Fig. 3, p. 217. As,
however, the number of individuals examined is small, the curve.is less
symmetrical than it would probably have been if a thousand specimens
could have been examined. The ideal curve indicated by that in Fig. 3
would doubtless have one maximum in the region of 24 and 25, as indicated
by the dotted line. Whether, however, the smaller crest of the curve
(between 40 and 50) would become more important can only be found
ON SOME PLYMOUTH HOLOTHURIANS. 2
out by further investigation. The usual number of gonadial tubes in
C. saxicola may therefore be fairly stated as 24 or 25. Curiously enough,
about 25 is also the average number of tubes given for the whole of the
50 specimens examined. There is variation, however, in the number
of gonadial tubes in this species between 10 and 61, as has already been
observed.
It is an interesting fact that the males appear to be more variable in
this respect than the females, although the small number of individuals
examined necessitates caution in making this suggestion. Of the 50
specimens examined 24 were females and 26 males. The number of
gonadial tubes in individual females varied between 10 and 33, whilst
in the males the variation lay between 15 and 61. The total number of
gonadial tubes in all the females was 477, giving an average of less
than 20, while all the males gave a total of 769, giving an average of
about 29-5.
Frequencies
10-15 16-20 21-25 26-30 31-35 36-40 41-45 46-50 51-55 56-60
Numbers of gonadial tubes.
Fig. 3.—Curve showing the frequencies of different numbers of the gonadial tubes in
50 specimens of Cucumaria saxicola B. and R.
Ordinates=frequencies; abscisse=number of gonadial tubes between
10 and 15, 16 and 20, and so on. The continuous line denotes the actual curve
obtained, the dotted one an approximation to the form of the curve if a larger
number of individuals were examined.
THE GONAD OF CUCUMARIA NORMANI.
The gonad of C. normani consists of a very large number of small
cylindrical tubes of almost even bore. These tubes are arranged as in
C. saxicola, on each side of the mesentery supporting the alimentary
canal. The tubes on both sides open into one longitudinal collecting
duct which extends in the mesentery some distance behind and in front
of a point about the middle of the length of the body. This duct is
218 J. H. ORTON.
continued anteriorly as the main gonoduct (see Fig. 2, p. 214). The
largest individual tubes in a very fine specimen were found to be about
3-0 cm. long, and less than 1 mm. wide.
The number of tubes was counted for the purpose of comparison with
those in C. sazicola in 6 individuals, of which 3 were males and 3 females.
In these specimens, whose lengths were (1) 5-3, (2) 7-2, (3) 8-2, (4) 8-6,
(5) 9-0, and (6) 12-5 ems., there were respectively 528, 582, 473, 513, 839,*
and 250 tubes. A similar large number of tubes was, however, observed
in all the specimens obtainable, namely, 30, of sizes similar to those given
in Table 1. A comparison with similar specimens of C. saxicola from
\ |
Oi '0 Vf
)
Fig. 4.—External view of the calcareous collar of C. saxicola drawn from a glycerine
preparation after separating the ventral piece from the adjacent right radial piece
(Xx 72).
Table 2 indicates at once the great difference in this respect between
the two species. The number in the specimen drawn for Fig. 2 was not
counted. In this figure it may be mentioned that the tubes shown are
chiefly those constituting the upper of several similar layers.
It is an interesting fact that the examination of the gonad of even
these few specimens of C. normani indicates a similar range of variation
to that observed in C. saxicola, namely, that the males (numbers 1, 2,
and 5) possess more gonadial tubes than the females (numbers 3, 4, and 6),
that the number of these tubes is not necessarily larger in the larger
individuals, and that within the species there is a wide range of variation
in the number of the gonadial tubes, which may vary from about 250
to more than 800.
* At least this number were present. Thirty-nine tubes which might have been broken
were not added to the total.
ON SOME PLYMOUTH HOLOTHURIANS. 219
The number of gonadial tubes was also counted in a few small specimens
of C. saxicola and in one small immature specimen of C. norman. In
specimens of the former of 3-8, 3-1, and 2-8 ems. in length, there were
respectively 8, 4, and 6 small tubes, while in the specimens of C. normani
of 3-3 cms. in length there were 199 tiny tubes.
It is thus evident that there is a marked difference between C. saxicola
and C.. normani in the characters of the shape and number of the gonadial
tubes.
ea
[lane
Fig. 5.—External view of the calcareous collar of C. normani, drawn from a glycerine
preparation after separating the ventral piece from the adjacent right radial piece
(x 7).
CHARACTERS OF THE CALCAREOUS COLLAR OF
C. SAXICOLA AND C. NORMANI.
The calcareous collars of both C. saxicola and C. normani consist alike
of 5 radial alternating with 5 interradial pieces, and in both forms three of
the ventral pieces, one radial and two interradials, are partially fused
together. (See Figs. 4 and 5.) There is, however, a general difference
in the relative stoutness of the collars in the two species, and some
differences in the shapes and mode of connexion of the parts.
220 J. H. ORTON.
The collar of C. saxicola is relatively delicate, that of C. normani
relatively stout. In specimens of the two species of about the same size,
both the radials and interradials in C. normani are stronger, wider, and
longer than in C. saxicola. (See Figs. 4 and 5.) In the latter species the
interradials are deeply bifurcated at the posterior end (see Fig. 4),
whereas in C. normani these plates are only slightly bifurcated (see Fig. 5),
and the radials of C. normani differ from those of C. saxicola in being
deeply constricted at the sides near the posterior end. Further, in
C. saxicola there is a long narrow calcareous connecting loop between the
radials and interradials, whilst in C. normani the similar connecting
pieces are short and stout and produced posteriorly to a point. Hence
the collar of C. saxicola is doubtless capable of much greater expansion
than is that of C. normani. The shapes of these collars can be easily
seen in preparations made by first soaking the anterior end of the animal
in glycerine and afterwards dissecting away the surrounding tissue and
mounting the collar in glycerine or glycerine jelly. This was found to
be a better method than treating the collars with potash.
CHARACTERS OF THE SPICULES AND TUBE-FEET IN
C. SAXICOLA AND C. NORMANI.
The characters of the spicules in C. sazicola have already been well
described by Brady and Robertson (4). These characters have been
confirmed by De Morgan (loc. cit.) and the present writer. They have
also been found to co-exist with the characters of the gonad and cal-
careous collar given above for the species.
The spicules of the adult C. normani have also been well described
and figured by Norman (2 and 3, Plate XI, Figs. 1, 2, 3, and 4) from his
specimen labelled A. Spicules identical with these have been found to
be correlated with a gonad consisting of a large number of small tubes
and a calcareous collar as described above.
It is therefore only necessary here to point out the main features of
difference between the chief kinds of spicules occurring in these two
forms. The chief body spicule in C. sazicola is plate-like and rhomboidal
in outline, having the opposite ends of one axis more or less produced.
The central portion of the spicule is perforated by four holes, placed
along the long axes and around the centre of the spicule. On the pro-
duced axis of the spicule one, two, or even three additional holes may be
developed. In some individuals the holes on the shorter of the long
axes are usually circular, while those near the centre on the long axis
ON SOME PLYMOUTH HOLOTHURIANS, i I
are more or less ellipsoidal in outline and larger than the former: in
other individuals, however, the relative sizes of these foramina are
reversed (see Brady and Robertson, 4, Plate LX XII, Fig. 3).
The chief body spicule in C. normani is also plate-like but ellipsoidal
in outline ; it has rarely more than four foramina, and bears on each sur-
face usually 12 rounded bosses or nodules. The foramina are arranged
diamond-wise along the long axes of the spicule. There are a great many
more spicules in a given area of the body wall in C. normani than in
C. saxicola, as may be easily seen in preparations of the skin: it is difficult
to obtain exactly comparable specimens, but at a rough computation one
would doubtless be well below the actual proportion in stating that they
are twenty times more numerous in C. normani than in C. saxicola.
The surface body spicules in C. saxicola are well shown in Brady and
Robertson’s figure (4, Plate LX XII, Fig. 2). They are microscopic, stellate,
of varying shape and size, but rarely more than 30 yu. wide, and scattered
Fic. 6.—A single tube-foot of C. saxicola, showing the kind and number of the podial
spicules (x about 30).
sparsely over the body. Usually they consist of a thin central plate
from which radiate tiny cylindrical rods about 12 ». long. On the other
hand, the corresponding spicule in C. normani is bell-shaped, being
slightly rectangular across the mouth of the bell, where on the average
they measure about 40 uw. by 36 uw. These spicules are almost uniform
in size, forming a continuous covering over the whole of the body and
passing on to the bases of the tube-feet. Their compactness may be
gathered from Fig. 8, which is a view through a low power of a micro-
scope of a portion of the body wall of a small specimen in which, however,
only one of the bell-shaped spicules is fully developed.
The podial spicules in C. saxicola are, as Pace has shown (loc. e't.),
usually perforated with a single series of holes. These are well shown
in Fig. 4, which is a drawing of a whole tube-foot well expanded (taken
from specimen 45, Table 1). One of the microscopic surface spicules
only is present. In C. normani, on the other hand, these spicules are
mostly larger, and with two or more series of foramina (see Fig. 5, p. 219).
222 J. H. ORTON.
This figure is a drawing of a tube-foot of a specimen of C. normani 5-3 cm.
long, taken from the right ventral ambulacral row—as was that of C.
saxicola, shown in Fig. 6, p. 221. A comparison of these two figures,
which may be regarded as typical, indicates the differences which occur
in the podial spicules of these two forms. Those in C. saxicola are rela-
tively few, mostly straight, with foramina in a single series, although
there may be spicules with more than one series. Those in C. normant,
on the other hand, are mostly broadly V-shaped, with foramina in two
or more series: some spicules, however, are straight, with foramina in
single series, as in C. saxicola. There are also a few bell-shaped surface
spicules around the base of the tube-foot.
The difference in the relative number of spicules in these two forms
Fic. 7.—A single tube-foot of C. normani, showing the kind and number of the podial
spicules (x about 65).!
is also well shown in these figures, and this difference is emphasized still
more by the fact that not all the sp‘cules in the tube-foot of C. normana
could be drawn. :
DISCUSSION OF SOME FORMER OBSERVATIONS ON
C. SAXICOLA AND C. NORMANI.
The establishment of undoubted specific and differential characters—
given in the preceding pages—for these two species enables a partial
clearing up to be made of the literature referring to these forms. Norman
(3) in 1893 described three specimens, A, B, and C, of Cucumaria obtained
at Polperro in 1865 as C. montagui. Subsequently Pace (1) in 1904
showed that one of Norman’s specimens, A, was undoubtedly the same
ON SOME PLYMOUTH HOLOTHURIANS. 223
as the Plymouth species known at that time at Plymouth as C. planczi,
while the other two, B and C, were similar to the species known at that
time at Plymouth as C. pentactes. After discussing the synonymy of
Norman’s C. montagui, Pace showed (1) that this name is a complex one,
whose original form could not be traced, (2) that C. planci Brandt
“cannot be applied to the very different species from Plymouth,” and
(3) that C. pentactes (Linneus) “is now generally regarded as an in-
2
determinate species.’ He therefore proposed to abolish all these names,
substituting C. normani for the Plymouth C. planci and specimen A of
Norman’s C. montagui ; and C. saxicola Brady and Robertson for the
Plymouth C. pentactes, and B and C of Norman’s C. montagui, which were
shown to be identical with a species described in 1871 by Brady and
Robertson as C. saxicola.
The researches here described support Pace’s contention that Norman’s
C. montagui consisted of two species, subsequently named by Pace as
C. normani Pace, and C. saxicola Brady and Robertson.
In 1905 Norman (2) wrote a paper maintaining his former views,
which at this stage can be stated to be as follows: That he considered
the Plymouth C. saxicola as the young of the Plymouth C. normani Pace,
and that both were really equivalent to C. montagui Fleming. Norman’s
main contention in this paper is that the Plymouth C. saxicola are the
young of the Plymouth C. normani. He, however, freely states that
“When young specimens of C. montagui, say 14 mm. long, should be
found having spicules agreeing with those of the adult, my view that B
and C are young forms of that species would require to be reconsidered.”
In further support of his view Norman cited the known facts that spicules
found in the young of some forms (for example, C. frondosa) disappear
in the adult, and that spicules which in the young of some forms are
smooth (for example, C. hyndmannz) become nodulous or thickened in
older specimens.
The correlation of differences in the gonad and calcareous collar with
the differences in the spicules described above is doubtless sufficient to
establish the distinctness of these two species. Fortunately, however,
tiny young ones of both species have been obtained, and so enable a
comparison of both forms to be made throughout all stages of growth.
Besides these, however, De Morgan also obtained tiny C. normani.
In his unpublished MS. he states: “‘I have examined specimens of
both species from about one centimetre to three inches in length, both
fresh and preserved in spirit, and find the plates that distinguish C,
normani confined to C. normani ; and those of C. saxicola to C. saxicola.”
224 J. H. ORTON.
Tiny specimens of C. normani were obtained by the writer from a
floating raft moored in Cawsand Bay, just outside Plymouth Sound.
These specimens measured about 13 and 14 mm.; in fact, just the size
Norman wished for. These specimens were examined while living, and
sketches made from the living animal of all stages of growth of the bell-
shaped spicules.
Subsequently a preparation was made of the skin of these animals
and a drawing of the spicules made in situ for Fig. 8, p. 225. This figure
shows the different stages of growth of the bell-shaped spicules and also
the degree in which these spicules are crowded in the surface of the skin.
The young of C. saxicola have been reared by the writer from the egg
to a size of about 5 mm., i.e. somewhat smaller than the tiny C. normana
mentioned above. In these no bell-shaped spicules developed, although
the body spicules were well formed. Specimens of all sizes of both species
have been obtained from dredgings, forming a parallel series from the
tiny ones mentioned above to the adults of sizes whose gonadial tubes
and other correlated characters have been described. The evidence for
the distinctness of these two forms is thus complete, whatever their
ultimate names may be decided to be.
THE GROWTH-STAGES OF THE BELL-SHAPED SPICULES
OF C. NORMANI.
The tiny specimens of C. normani mentioned above presented an
opportunity of following the development of the bell-shaped surface
spicules of this species. These spicules develop in four well-defined
stages. In the earliest stage they consist of a microscopic plate forked
at both ends (see Fig. 8 for this, as well as for the following stages). At
a later period of development each of the forked ends divides dichoto-
mously twice to give two succeeding well-marked stages. At the same
time the central portion of the spicule becomes wider and thicker, and
the growing arms arch outwards to form a hemisphere. At this stage
one branch of each of the last-formed bifurcations grows towards a
similar branch derived from the subdivision of the adjacent primitive
prong. These branches grow together, but frequently become slightly
forked again before fusing to form the rim of the spicule. The whole
spicule at this stage becomes thickened, and generally two branches of
the third order of division persist as projections at each of the four
corners and one in the middle of each side of the rim when the spicule is
fully formed. There are, however, sometimes variations from the general
course. Occasionally three or five original prongs may develop and a
b>
ON SOME PLYMOUTH HOLOTHURIANS. 25
three- or a five-rayed spicule is produced, at other times further sub-
division of the branches of the third order occurs, giving rise to bell-
shaped spicules slightly different from the usual form ; the normal form
is, however, the one described above.
\
GR
pe ee
OG VF co)
Fic. 8.—The campanulate surface spicules of C. normani. Drawn from a piece of the
skin (mounted whole) of a specimen 13 mm. long to show a series of stages in the
development of these spicules and their compact arrangement.* One fully
developed spicule is depicted (x about 300).
THE SYNONYMY OF C. SAXICOLA BRADY AND
ROBERTSON AND OF C. NORMANI PACH.
It will be evident from the foregoing accounts that the synonymy
of the two species mentioned above may be expected to be and actually
is in a highly confused state. This confusion has been rendered still
worse by the fact that continental zoologists have regarded C. montagur
as a good species, whereas it has been shown to be a complex one. Thus
according as the one or the other constituent of C. montaqui has fallen
into the hands of these zoologists, the other constituent—on the Continent
—has been given another name. There can be little doubt that the two
species discussed in this paper do occur on the Continent, but at present
* Drawings were made of some of these stages of development from the fresh living
animal as a safeguard against their possible subsequent alteration in preservation. It
was found, however, that the spicules in the mounted specimen agreed with the drawings
from the living animal.
226 J. H. ORTON.
pass under other names. It is therefore improbable that the literature
on these Holothurians will be properly purged until some specialist can
take the whole group into consideration and obtain and compare type
specimens from the various authors and stations.
A few observations on the literature may, however, be useful. From
the establishment of the complex nature of Cucumaria montagui, it seems
highly probable that the earlier British naturalists were familiar with
the constituents of the complex under the names of Holothuria pentactes
and H. pentactes var. montagui Fleming. The descriptions of these
animals are, as Norman has already pointed out (1905), insufficient to
enable us to identify them. These names should therefore be abandoned
on this ground if on no other. In 1828 Fleming (5) called H. pentactes
var. montagui definitely H. montagui, but, as Pace (1904) pointed out,
Fleming unfortunately based his description of this form on specimens
which were obtained from the Firth of Forth and which may have be-
longed to another species. Thus we have no criterion as to what Cucu-
maria moniagui really is.
In 1871 Brady and Robertson (4) discovered a species of Cucu-
maria in Westport and Birterbury Bays, Ireland, and gave a good
description of the spicules. This species they named C. saaicola.
In 1882 Barrois (6) found a species of Cucwmaria at Concarneau
on the shore which he called C. lefevrei. This species resembles
that described by Pace (1904) as C. normani closely in the characters
of its spicules (as described) and its calcareous collar. It is,
indeed, highly probable that these are the same species, but it would
be necessary to compare actual specimens of these forms to be certain
of their identity. If, however, such were established Pace’s name would
have to give way to that of Barrois’. It should be pointed out that
Barrois’ figures do not agree with his description.
In 1889 Hérouard (7), having apparently never seen Brady and
Robertson’s description of C. saxicola, described a form apparently
identical with the latter as Colochirus lacazei n.sp. It is a somewhat
amusing fact that this writer was roundly accused shortly afterwards
by Marenzeller (8, 1893) of wilfully renaming what he well knew was
C. montagui. It is also of interest that Marenzeller—lke Pace—states
confidently in the same paper that C. montagui is quite and obviously
different from C. lefevret Barrois. Now Marenzeller’s C. montagui were
sent to him by Norman (2, p. 389), who definitely states they were like
his specimens B and C, which have been shown above to be C. sazzcola.
About the same time Ludwig and Hamann (9, 1892) state, but with-
ON SOME PLYMOUTH HOLOTHURIANS. 227
out giving a discussion, that C. lacazex Her. =C. lefevrer Barrois. It is
thus a curious fact that two pairs of men, one in England and one on
the Continent, should hold independently similar conflicting views on
what appears to be the same pair of species.
A little later Koehler (10, 1893), discussing the synonymy of C.
montagui Fleming, gives as synonyms among others C. lacazei Heér.,
Holothuria montagui Fleming, and Cucumaria pentactes Bell, pointing
out, however, at the same time that C. montagui differs from C. lefevrer
in the shape and number of its genital tubes. He also figures spicules
of C. montagui which are identical with those of C. saxicola. Now
Koehler also received his specimens of C. montagui from Norman, who
admits, as we have seen, that those sent were identical with his specimens
B and C, i.e. with C. saxicola.
About this time Bell (11) added his quota to the confusion by giving
as synonyms Holothuria montagui Fleming, Cucumaria pentactes Forbes,
C. elongata Diib. and Koren. In 1902 Perrier (12) obtained C. elongata
from the Gulf of Cadiz, and stated that this species is fundamentally
different from C. montagui: he did not indicate, however, what were
the characters of his C. montagui. Kemp (13) in 1905 described C.
elongata Diib. and Kor. from Ireland and figured its spicules. Subse-
quently I obtained specimens of this species from various localities in
this neighbourhood (see description on p. 229) from which there
can be no doubt of the distinctness of this species.
From the foregoing historical account it appears that the complex,
Holothuria montagui, of the older naturalists has subsequently been
renamed as Cucumaria saxicola Brady and Robertson, C. lefevrei Barrois,
Colochirus lacazei Hér., and C. normani Pace, as well as other names.
Of these four names one pair, C. saxicola and Colochirus lacazei, seem to
be undoubtedly synonymous ; from the apparent identity in the char-
acters of the spicules and genital tubes it is highly probable also that
the other pair are synonymous. It is important, however, that these
latter forms should be compared in actual specimens before making
further alterations of names; hence until the whole of the Kuropean
Cucumarians are revised by a specialist, the name C. normani Pace may
be said to stand for that constituent of the old C. montagui whose char-
acters are summed up in the foregoing pages.
NEW SERIES.—VOL. x. NO. 2. JUNE, 1914. P
228 J. H. ORTON.
CORRELATION IN THE CHARACTERS OF THE GONAD AND
AMBULACRA IN THE GENUS CUCUMARIA.
The difference in the character of the gonad in C. saxicola and C.
normant described in the foregoing pages suggested that similar differ-
ences might occur in other Cucumarians. On investigating the other
OW
Wa ee
ee ada bs Rises
Fie. 9.—View of Cucumaria saxicola, showing the five ambulacral rows (x #).
The view is mainly lateral from the right side, but the posterior end of the
animal is turned somewhat dorsalwards to show in this region the three ventral
ambulacral rows. These rows are seen to consist of suctorial tube-feet. On the
upper right side of the figure are seen the two dorsal ambulacra, the right one
of which is continued in profile to the posterior end of the body; both rows are
seen to consist merely of ambulatory papille, except at the anterior end, where
there are a few suctorial tube-feet.
species of this genus occurring in this district, it was found that they
fall into two groups, having the following characters :—
Group A. Species whose gonad consists of numerous short cylindrical
tubes, and whose dorsal as well as ventral ambulacra.
have well-developed tube-feet.
In this group fall the species normani, hyndmanni, elongata.
(Compare Fig. 10, p. 230.)
Group B. Species whose gonad consists of relatively few, large, club-
shaped tubes and whose dorsal ambulacra contain mostly
ambulatory papille, which are less numerous than the
tube-feet in the ventral rows, but with a few definite
tube-feet at the anterior ends. (See Fig. 9, p. 228.)
In this group fall the species saxicola and brunnea.
Now the genus Colochirus differs in the literature (9, p. 343) from the
genus Cucumaria mainly in having ambulatory papille in the dorsal
ambulacra. It is possible, however, that when the gonad in species of
ON SOME PLYMOUTH HOLOTHURIANS, 229
Colochirus is examined it may be found to be similar to that in C. saxicola
and C. brunnea.
With regard to the Group B given above, it is an interesting fact that
Norman himself (2, p. 382) states that some of his specimens (which
have been shown to belong to C. saxicola) would be placed by some
naturalists in the sub-genus Colochirus merely on account of the characters
of the dorsal ambulacra, and also that Hérouard placed what is almost
certainly C. saxicola in that very genus as Colochirus lacazei. It is not
improbable, therefore, that when the European Cucumarians are revised
the whole of the genus Cucumaria may be divisible into two groups
similar to those given above, and that those specimens having the
characters of Group B may have to be designated as species of the genus
Colochirus.
PART II.
ON THE OCCURRENCE OF CUCUMARIA ELONGATA DUB.
AND KOR. AND THYONE RAPHANUS DUB. AND KOR.
IN THE PLYMOUTH DISTRICT.
During the period from March, 1911, to Sept., 1912, numerous specimens
of Cucumaria elongata Diib. and Kor. were obtained at various stations
in the Plymouth district. These specimens were nearly all taken in a
dredge with a fine-meshed net, worked from the Laboratory steamer
Oithona. The depths from which these Cucumarians were dredged
varied from about 5 to about 30 fathoms, and the nature of the bottom
in which they were living was almost invariably muddy, but varying
from fine mud in Plymouth Sound and off Rame Head, to muddy gravel
in the region about 2 miles south of Wembury Bay, and to fine muddy
sand on the Rame-Eddystone Trawling Ground. (See 16 and 17.*)
There can be little doubt that C. elongata is fairly common in this district
on all the muddy grounds, and is probably not uncommon on the fine
sand of the outer grounds.
The captures of this species have been made at 15 stations within a
small area, so that the distribution can be described with reference to
the various grounds already defined in earlier volumes of this Journal
(16* and 17) as follows :-—
Plymouth Sound. On one occasion (18th May, 1911) 4 specimens
* See these references for a description of the grounds in the Plymouth district. Since
those accounts were written in 1899 and 1904 there has been a good deal of mud deposited
on the various grounds just outside the Sound from dredgings in the harbour.
230 J. H. ORTON.
were taken in one haul of the dredge in the middle of Plymouth Sound,
while on the date 23rd March, 1911, one specimen was obtained similarly
in the same locality. Many unsuccessful hauls have, however, also been
made.
Off Rame Head 6 specimens were taken in the dredge in mud about
1 mile south of the headland. Five of these specimens were taken in one
haul of about five minutes’ duration.
From the region of the Mewstone “‘ Amphioxus”’ Ground, between
and about the points 14 to 2 miles south of the Mewstone and Yealm
Point, captures of C. elongata were made in the dredge on seven different
occasions. On the 3rd June, 1912, 12 specimens were obtained in about
half a day’s work with the fine-meshed dredge. In all, about 20 specimens
have been obtained from this ground.
se
e
2
°
<
ct
¢
¢
a
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¢
Lif
G
Ss
“
i
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Fic. 10.—Cucumaria elongata well expanded, showing the tentacles and dorsal ambu-
lacra (x 3/2).
Two specimens have been taken on different occasions on the Rame-
Eddystone trawling grounds, both from a position about 5 to 5} miles
S. 4 E. of Rame Head.
The total number of specimens obtained from all the grounds is about
35. They varied in size from about 1-4 cm. long and 2-5 mm. broad to
6-6 cm. long and 9 mm. broad at the broadest part. The specimens
when caught were U-shaped, or more or less S-shaped, with a tapering
posterior end, and varied in colour from a purplish brown to a browny
grey.
NOTES ON CUCUMARIA ELONGATA.
The discovery of this species in the Plymouth district is of some
interest with regard to the unravelling of the synonymy of British
Cucumarians. Bell in 1892 (11, p. 38) gives C. elongata Dib. and Kor.
ON SOME PLYMOUTH HOLOTHURIANS. 23l
as a synonym of C. pentactes, most of the specimens of which he records
from Plymouth.
It has been shown in the foregoing pages that the Plymouth species
called C. pentactes in 1892 is undoubtedly the same as Brady and Robert-
son’s C. saxicola. This species is, however, totally different from
C. elongata Diib. and Kér., as may indeed be gathered from the description
of this animal given by Diiben and Koren (14). Kemp (13) has recently
given a good description of the external characters and spiculation of
C. elongata Diib. and Kor. from Ireland. The Plymouth specimens agree
well with Kemp’s description and with that given by Diiben and Koren
themselves. There is thus no doubt that C. elongata is a good species
and quite different from other Plymouth Cucumarians.
Some of the specimens obtained have been kept under observation
alive for as long as nine months embedded in fine sand. In life the
posterior end of the body, “the tail,’ protrudes above the surface of the
Fic. 11.—Drawing from life of the “tail” of Thyone raphanus protruding from the
sand (x 4).
sand presumably for the purpose of respiration. (Comp. Fig. 11.) The
body is bent in a U- or S-shaped fashion as was observed in the freshly
caught animal. During the whole of the period these animals were kept
the tentacles have rarely been seen above the surface of the sand.
It is possible, therefore, that the animal feeds mainly by ingesting mud
or sand, as it is apparently much too sluggish to search actively for food.
The tentacles in this species are very short, as may be gathered from
Fig. 10, which is a drawing of a specimen narcotized by menthol. In
this figure is well shown the double rows of tube-feet near the middle
of the body and the gradual passage into single rows towards both the
tapering ends of the body.
It has already been noted that the gonadial tubes of this species are
numerous and cylindrical, resembling those of C. normani both in shape
and approximately in numbers. The retractors of the buccal mass are
extremely short and altogether poorly developed.
The gonads of female specimens taken in June and July were found
to contain nearly ripe eggs; in July, 1912, a specimen was obtained
232 J. H. ORTON.
with active sperm and an unsuccessful artificial fertilization tried. It
is highly probable, however, that the species breeds a little later than
this time of the year, as specimens taken in early May and September
had only immature ova in the gonad.
ON THYONE RAPHANUS DUB. AND KOR.
Nine specimens of Thyone raphanus Diib. and Kor. were taken at
various times between July, 1911, and July, 1912. These specimens
were captured, except in one case, in the fine-meshed dredge in muddy
sand or in muddy gravel in depths from about 12 to 30 fathoms. Four
specimens were taken on one occasion 1} to 2 miles 8. of the Mewstone:;
and on another one specimen 1} miles off Yealm Point. Two were
obtained in July, 1911, about 3 miles 8. of Rame Head, and two in May,
™ ace OL LTS v=
% vy vas . W
By ONE pss EN
Ao sinew ¢
YPN T
Fie. 12.—Thyone raphanus. The body portion was drawn from the living animal and
the tentacles afterwards added from a preserved specimen (~ $).
1912, in a position 5 to 53 miles 8. } E. of Rame Head. In the same
month one specimen was taken in the trawl on the inner portion of the
Rame-Eddystone trawling grounds.
The specimens varied in size from 2°5 cms. long by 7 mms. wide at the
widest part to 6:2 cms. long by 1:1 cms. wide, the measurements being
taken from the preserved animals. Their general colour was of a creamy
white, and when obtained from the dredge they were bent in the form
of a U. In none of the specimens examined were ripe sexual products
found, hence it is likely that breeding occurs during the winter months.
The spicules from the skin, tube-feet, and tentacles agree closely with
those given by Diiben and Koren (14, Plate V, Figs. 49 to 55). There
are, however, some spicules with bosses arranged concentrically around
the foramina, but probably the Figures 50, 51, and 54 in the afore-
mentioned plate are an attempt to represent these bosses. The calcareous
ON SOME PLYMOUTH HOLOTHURIANS. Dan
collar is shown in Fig. 13, from which it will be seen that it is very similar
to the portion figured by Marenzeller (18): the connecting pieces are
not calcified in the smaller forms. The polian vesicle is single and very
IN
ef
Va
yo8
oo
Wo
|
Fie, 13.—External view of the calcareous collar of Thyone raphanus Diib. and Kor.
drawn from a glycerine-jelly preparation after separating the ventral piece
from the adjacent right radial piece: the polian vesicle and the stone canal are
shown attached to the collar* (x 9).
long, and longer in the larger than in the smaller specimens ; in preserved
specimens it may be dilated at the proximal or the distal end, or at both
ends.
* The constituent pieces of the collar are somewhat delicate, so that drawings from
potash preparations are liable to be inaccurate, inasmuch as the middle portion of the
radials is very thin and might easily be abraded to give such a figure as is drawn by
Barrois for 7. poucheti (loc. cit.).
234 J. H. ORTON.
It is unfortunate that Diiben and Koren did not figure the calcareous
collar and polian vesicle of the type specimens, for Barrois has described
a form which only differs from 7. raphanus in having a bifurcated polian
vesicle. Neither of these authors, however, found more than one speci-
men. The Plymouth specimens agree with Barrois’ form except in the
calcareous collar as figured by Barrois and the presence of tube-feet on
the “tail” (cf. 6, Plate I, with Fig. 11, p. 231, and Fig. 13, p. 233), and
they agree also with Marenzeller’s form except in the polian vesicle
as figured by Marenzeller. As, however, Théel (19) had already doubted
the distinctness of 7. poucheti, it is very probable that all these forms
belong to Diitben and KGren’s species T. raphanus. There is some ground
for believing that Barrois’ figure of the delicate calcareous collar of his
Thyone is not a typical one; and Marenzeller’s figure of a bifurcated
polian vesicle requires confirming in more specimens. Therefore for
the present it has been deemed advisable to refer the Plymouth forms
to T. raphanus Dib. and Kor. If, however, the type of the latter
species is found to possess constantly a bifurcated polian vesicle, then
the forms from this district probably belong to 7. poucheti Barrois.
Several individuals of this species were kept under observation alive
for some months in the same dish with the C. elongata mentioned above.
These specimens maintained their tails above the surface of the sand,
as is shown in Fig. 11, in the same way as did the Cucumarian. The
tentacles have, however, only been seen expanded above the surface of
the sand on two occasions when the water was becoming foul, and it
was observed that the body was maintained bent in a U-shaped manner.
The tentacles in this species are very short (see Fig. 12), as in C. elongata.
This reduction of the tentacles and buccal retractors and the correlated
tailed posterior end are also found in the group Malpodiida, which also
inhabit muddy situations and have been found to ingest the muddy sand
in which they live (15). Doubtless these characters of the tentacles are
related to the manner in which all these animals feed, for short stiff
tentacles would be much more useful for ingesting mud or fine sand than
the long dendritic tentacles such as are found, for example, in some other
species of Cucumaria and Thyone. Thus these mud-dwelling Holothurians
form one more example of that interesting phenomenon in nature,
namely, the occurrence of similar adaptations in different animals for
performing the similar functions necessitated by a similar mode of life.
bo
10.
Ble
12.
13.
14,
15.
16.
We
18.
ON SOME PLYMOUTH HOLOTHURIANS. 235
REFERENCES.
. 8. Pace. Notes on two species of Cucumaria from Plymouth. Journ.
M.B.A., N.S. Vol. VII. 1904-7. p. 305.
. A. M. Norman. On Cucumaria montagui Fleming. Ann. and Mag.
Nat. Hist. Series 7. Vol. XVI. 1905. p. 352.
. A. M. Norman. Cucumaria montagui Fleming and its Synonymy.
Ann. and Mag. Nat. Hist. Series 6. Vol. XII. 1893.
. G. S. Brady and D. Robertson. Descriptions of two new species of
British Holothuroidea. Proc. Zool. Soc. 1871-2. p. 690.
. J. Fleming. A History of British Animals. Edinburgh, 1828. p. 483.
. T. Barrois. Cucumaria lefevrei (n.sp.). Cat. des Crustac. Podophthal.
et des Echinodermes, p. 52. Lille, 1882.
. EK. Hérouard. Hol. des cdtes de France. Arch. de Zool. Exp. (2).
Vol. VII. 1889. p. 535.
. E. von Marenzeller. Resultats des Campagnes Scientifiques. Albert
1 de Monaco. Holothuries. Part VI. 1892. p. 15.
. Ludwig and Hamann. Bronn’s Tier-reich. Buch 1. 1892. pp. 3, 48,
and 343.
R. Koehler. Sur la Détermination et la Synonymie de Quelques Holo-
thuries. Bull. Sci. Fr. et Belg, XXV. Series 4. Vol. IV. p. 355.
1893.
F. J. Bell. Catalogue of Brit. Echinoderms in the British Museum.
London, 1892. p. 37.
E. Perrier. Travailleur et Talisman. “ Holothuries.” 1902. p. 495.
S. Kemp. The Marine Fauna of the West Coast of Ireland, Part III.
Ann. Rept. Fisheries of Ireland, 1902-3, Part II, App. VI, p. 176.
1905.
M. W. Diiben and J. Koren. Ofversigt af Skandinaviens Echinodermes.
Kongl. Vetensk. Akad. Hand]. for Ar. 1844. p. 301.
J. H. Gerould. The Anatomy and Histology of Caudina arenata Gould.
Proc. Boston Nat. Hist. Soc. Vol. XXVII. 1897. p. 12.
E. J. Allen and 8. Pace. Plymouth Marine Invertebrate Fauna. Journ.
M.B.A. Vol. VII. No.2. 1904. pp. 169-72.
E. J. Allen. On the Fauna and Bottom-deposits near the Thirty-fathom
Line from the Eddystone Grounds to Start Pot. Journ. M.B.A.
Vol. V. No. 4. 1899. pp. 387-440.
E. von Marenzeller. Beitrage zur Holothurien- Fauna des Mittelmeeres.
Verh. Zool.-Bot. Vereins in Wien. Band 27, p. 118. 1877.
19. H. Théel. Voyage of H.M.S. Challenger. Zoology. Vol. 14. Report
on the Holothuroidea. Part II, p. 136. 1885.
[ 236 J
On Anthura gracilis (Montagu).
By
BE. W. Sexton.
With 12 Figures in the Text.
On August 14th, 1913, a fine male specimen of Anthura gracilis was
taken by the Ovthona, in the young-fish trawl working at the surface at
night, about six miles west of the Eddystone.
An excellent account of the female and young male has been given
by Norman and Stebbing (Trans. Zool. Soc., Vol. XII, p. 122), but,
as far as I am aware, the adult male has never been described, and as
it differs considerably in appearance from the female, I have figured it
here, adding to Norman and Stebbing’s description some notes made
on the Plymouth specimens.
Female specimens are occasionally found in the dredgings from Ply-
mouth Sound, but males are rarely captured.
Very little is known of the habits of the species. The females are
evidently much more sedentary than the males; they are more heavily
built, the body stouter, the mouth organs larger, and the first gnatho-
pods much heavier and bigger than in the male (cf. Figs. 9 and 11).
Stebbing, in his History of Crustacea, 1893, p. 335, makes an interesting
suggestion with regard to these animals and their mode of life. In
referring to the Hisothistos vermiformis of Haswell and its habit of living
in the tube of a Serpula with its tail at the mouth of the tube, the uropods
and telson mimicking in appearance the operculum and branchie of
the worm, he says: ‘‘ Probably the British Anthura gracilis may use a
similar shelter, since it is undoubtedly dredged up in company with
shells and stones on which the tubes of Serpule are abundant.” An
observation recently made by Mr. Crawshay (Mar. Biol. Journ., Vol. IX,
No. 3, 1912, p. 351) appears to support this suggestion, at least as far
as the female is concerned. In the material trawled at forty-two fathoms
he found one specimen of this species, a female, head inwards in a tube
of Sabellaria spinulosa. He noted the position of the tail appendages
lying nearly flush with the opening of the tube, and added: “ Their
ON ANTHURA GRACILIS (MONTAGU). 237
appearance was so deceptive to the eye that they might easily be mis-
taken at a rough glance for the anterior region of the original occupant
of the tube.’’ On the other hand, it must be stated that an examination
Anthura gracilis. Fie. 1.—g, dorsal view. Eddystone specimen, x 17.
of several hundred tubes of Sabellaria spinulosa-dredged in Plymouth
Sound did not yield a single Anthura. The female specimens collected by
the Laboratory have been generally found after the dredgings have been
238 E. W. SEXTON.
left standing for some time; as the water becomes foul the animals
crawl out of the crevices and holes in which they have been hidden.
The males are very active. Mr. Clark, the naturalist on board the
Oithona, says of the Eddystone specimen that when caught it darted
about from side to side with quick jerky movements. This specimen is
the largest male yet recorded, measuring 10 mm. from the tip of the
rostrum to the tip of the telson. Of the three other males caught at
Plymouth, one taken off Drake’s Island measured 8 mm.; the other
two recorded by Garstang (Mar. Biol. Journ., Vol. II, p. 123) were
4mm. and 5 mm. long and had 9 and 12 joints respectively in the flagel-
Anthura gracilis. Fire. 2.—Telson, 2, x 42.
Cyathura carinata. Fic. 3.—Telson, 2, x 42.
a, muscle attachment; 5b, muscle attachment, inner uropod ;
st, statocyst.
lum of the upper antenna. A suggestion has been made that the male
on reaching sexual maturity has an active but short life. I think the
note just referred to helps to solve this question. These two small males
had already reached sexual maturity, as shown by the development
of the sensory sete of the upper antenne (a secondary sexual character
appearing at maturity), but that they were not nearly full grown can
be seen on comparison with the Eddystone specimen. The number of
joints in the flagella increases with age. The Eddystone specimen—l0
mm. in length—had 20 joints developed in the flagellum of the upper
antenna, thus showing that the period of sexual maturity and activity
had extended over a length of time suflicient to allow for several moults
and the consequent considerable increase in growth.
ON ANTHURA GRACILIS (MONTAGU). 239
A very interesting point in this species is the presence of statocysts
in both male and female. I am indebted to Dr. Calman for drawing my
attention to the question of the existence of these organs in the
Anthuride ; to Dr. A. Thienemann for sending me some of the actual
specimens referred to in his paper (Zool. Anz., Vol. XXVI, pp. 406-410) ;
and to Dr. Allen for his kindness in sectioning specimens of both
Cyathura carinata and Anthura gracilis.
The species, of which the statocysts are so fully described by Thiene-
mann, proved to be Cyathura carinata (Norman and Stebbing, Trans.
Zool. Soc., Vol. XII, p. 124) as suggested by Gurney (Trans. Norfolk
Min |
iu
Anthura gracilis. Fic. 4.—Horizontal section, upper part of statocyst on the right side,
showing duct, 100.
Fic. 5.—Horizontal section, lower part of statocyst on the left side,
showing the crystalline bodies of the statolith, x 435.
d, duct; m, muscle; sé, statolith; v, vesicle.
Nat. Soc., Vol. VIII, p. 433). I have figured the telson of both species
for comparison.
It will be seen that the general structure of the statocysts is exactly
the same in both genera, but the details naturally vary a little. It is
impossible to see these organs in specimens preserved in the usual way.
Dr. Thienemann, in reply to a question as to whether they were to be
observed in the living animal, said: “So viel ich weiss, waren die Organe
am Lebenden nicht zu sehen; dagegen waren Sie sehr deutlich bei Auf-
hellung mit Nelkenol, Kreosot oder Zylol.” Dr. Thienemann adds the
interesting note that in two species of another genus of the Anthuride
examined by him, viz. Calathura brachiata Stimps, and C. norvegica
G. O. Sars, in Bergen Museum, no statocysts were found.
Each statocyst consists of an oval vesicle, lying embedded in the
240 E. W. SEXTON.
tissue of the anterior part of the telson, nearer the dorsal surface. A
very fine tube or duct communicating with the exterior rises from the
upper surface of the vesicle, on the side away from the median line
(Fig. 4d), while at the bottom of the vesicle, towards the median line, the
crystalline bodies of the statolith can be seen (Fig. 5 st). A strong muscle
is attached to the anterior wall of each statocyst ; much stronger in
Anthura than in Cyathura ; it appears to be attached at its anterior end
to the chitin of the telson. This attachment looks like a coloured oval
body, and is as noticeable as the statocyst itself, seen am situ (Fig. 2 a),
but an examination of the sections shows its construction. The two dotted
bodies (Fig. 2 6) are similar muscle attachments in the inner uropods.
DESCRIPTION.
Body cylindrical, much more stoutly built in the female than in the
male, with strongly marked longitudinal keels, three in the female, four
in the male. In both sexes there is a dorso-lateral keel on either side,
starting in the male just behind the eye, and finishing at the end of the
peraeon, while in the female it runs the whole length of the body, from
the tips of the lateral angles of the head to the end of the pleon. In both,
also, the mid-ventral keel is well developed. The male has, in addition,
on the head and peraeon, a smaller but well-defined mid-dorsal keel,
most marked on the anterior segments.
Pleon. In the female the first five segments are coalesced and equal
in length to the last peraeon-segment, in the male these segments are
- distinct and equal in length to the two last segments of the peraeon.
Head in the female almost square, with a short rostrum and with the
anterior lateral angles also produced and projecting a little further
forward than the rostrum. In the male the shape is quite different,
the front of the head from the eyes tapering gradually downwards to a
strong obtuse rostrum (Fig. 1).
Eyes black, very prominent in the male, and of great size, occupying
nearly half the surface of the head and almost meeting dorsally ; om-
matidia very large, distinct from each other, corneal facets convex, the
whole eye resembling a blackberry. In the female the eyes are much
smaller, round in shape, and flat, not prominent.
Upper Antennae in the female shorter than the lower antennae. The
first joint of the peduncle is equal in length to the second and third taken
together ; flagellum two-jointed, consisting of one long jomt without
setae, and a minute terminal joint carrying a cluster of eight to ten setae
ON ANTHURA GRACILIS (MONTAGU). 241
of varying lengths, and three long sensory filaments. In the male the
long flagellum reaches to the posterior margin of the second peraeon-seg-
ment, and consists of twenty joints in the Eddystone specimen (Fig. 1),
the first joint short, the second constricted proximally and expanded
distally. All the joints except the first are fringed with very long,
delicate, outstanding setae, giving a brush-like effect to the antenna.
The smaller male from Drake’s Island had sixteen joints in the flagellum.
Lower Antennae. The second joint of the peduncle is greatly expanded
distally ; the third very small; fourth rather longer ; the fifth equal in
length to the third ; flagellum in the female four-jointed, the terminal
jomt furnished with a thick cluster of long setae. The flagellum in the
male is six-jointed, the first joint as long as the others taken together.
_~
(
we
/
Anthura gracilis. Fie. 6.—Abnormal maxillipeds, 3, Drake’s Island specimen, x 75.
Via. 7.--Maxilliped, 3, Eddystone specimen, 75.
Fic. 8.—Maxilliped, 9, 10.5 mm., x 75.
Mouth organs as described by Norman and Stebbing. They are larger
in the female than in the male. The mandibles have a three-jointed
palp ; the falcate process terminates in three blunt teeth, the thin blade
below with five serrations, the serrations more acute in the males ex-
amined than in the females.
Mazillipeds. Palp one-jointed (Figs. 7 and 8) tipped with a row of
four stiff slightly curved setae. In Fig. 6 the maxillipeds of another
male are figured, showing an abnormality in that a second and very
distinct joint is developed. The specimen was perfectly normal in all
other particulars, but it serves to illustrate the danger of describing
species from one or two solitary specimens.
Gnathopod 1. In the male the first and second joints are subequal,
both produced distally on the upper side over the succeeding joint ;
third joint produced on the under side. The fifth joint or hand narrowly
pyriform, widest proximally, tapering to the insertion of the finger,
rounded above, and turned at a different angle to the rest of the appen-
242 E. W. SEXTON.
dage ; palm covered on the under surface with long stout setae ; finger
carrying one small spine and a few setae distally ; nail strong, curved.
In the female (Fig. 11) the gnathopod is much larger and stouter
than in the male. The first joint is as broad as long, distally expanded ;
second joint slightly longer, furnished on both margins with a pectinate
scale-like armature. This armature is also found on the anterior margins
of the fourth, fifth, and sixth joints. The hand as described by Norman
and Stebbing is pyriform, upper portion well rounded, palm with a well-
developed process projecting forward near the base; inset on the under
surface near the finger is a cluster of stout setae similar to those of the
male.
Anthura gracilis. Fia. 9.—First Gnathopod, upper surface, 3, Eddystone specimen,
x 42.
Fic. 10.—First Gnathopod, under surface, 3, Eddystone specimen,
x 42.
Fic. 11.—First Gnathopod, upper surface, 2, « 42.
Gnathopod 2 and Peraeopod | alike in construction in both sexes. The
first joint is longer than the second ; third half the length of the first,
strongly lobed posteriorly ; fourth very small, triangular ; fifth as long
as the first, nearly parallel-sided, front margin finely pectinate, the
microscopic spines arranged in semicircles giving the effect of over-
lapping pectinate scales down the whole length of the margin; two
strong spines inset at the insertion of the finger. Finger long, finely
pectinate, carrying one strong spine and some setae at the base of the
nail, and two or three small spines proximally. Scattered over all the
appendages are many mobile sensory hairs, each hair consisting of a
shaft and a fine flagellum. These hairs are most numerous on the palm.
Peraeopods 2, 3, 4, and 5 alike in construction, a little shorter and
stouter in the female. The first joint is slightly longer than the second ;
third and fourth shorter, subequal in length; fifth about the length of
the first; finger two-thirds the length of the fifth. The first three
joints are constricted proximally, the third lobed posteriorly. In all
ON ANTHURA GRACILIS (MONTAGU). 243
the peraeopods the anterior margins of the fourth and fifth joints are
pectinate, the spines in the female being longer and more setiform in
character ; the finger also bears some small spines: two stout spines
are inset together at the anterior distal angle of these joints, and a long
plumose sensory hair at the posterior angle of the fourth jomt. In the
male the third joint of the fifth peraeopod is provided with two long
sensory plumose hairs as long as the succeeding joint.
Pleopods 1 in both male and female, with the outer rami greatly
expanded, forming a kind of operculum, reaching in the female to the
extremity of the fifth segment of the pleon, in the male considerably
Anthura gracilis. Fic. 12.—Second pleopod, 3, x 42.
beyond the end of the pleon. The modified second pleopod of the male
is figured (Fig. 12).
Telson and uropods as described by Norman and Stebbing, so con-
structed ‘‘as to resemble nearly a cylinder, with one side (the dorsal)
cut obliquely away. The telson has the apex truncated, and is of the
same length as the inner branch of uropods. Outer branches of uropods
neatly meeting at their bases dorsally, broadly lanceolate, curved,
rather longer than the first joint of the inner branch.”
Colour, yellowish white, with markings of a brownish pigment in the
form of cloudy patches. The colour varies considerably, probably with
the nature of the ground on which the animal lives, some specimens—
as the Eddystone one—having only a few small dotted patches on the
head and peraeon, others again being nearly covered with the brown
tint.
NEW SERIES.—VOL, X. NO. 2. JUNE, 1914. Q
[ 244 J
On Leptonereis glauca Clpde., and the
Genus Leptonereis Kinberg.
By
L. N. G. Ramsay, M.A., B.Sc.,
Carnegie Research Scholar, Christ's College, Cambridge.
With Plate 1 in the Text.
INTRODUCTORY.
In February of this year Mr. J. H. Orton collected a number of small
nereids on the piles of a wharf at the Great Western Docks at Millbay,
Plymouth. These he kindly handed over to me for identification, and,
along with other material collected at Plymouth in March, they form the
basis of this paper.
These nereids proved to be none other than the little-known Leptonereis
glauca of Claparéde, of which the only specimen hitherto recorded from
the shores of this country was found by Major E. V. Elwes at Oddicombe
(8, p. 351) some years ago.
Claparéde (3, p. 90) described the species from specimens obtained
by him at Naples about 1870. He gives a good description and figures,
but no particulars as to its numbers or habitat. It was next met with by
de St. Joseph, who found it commonly in dredgings at all depths on the
coasts of Dinard (6, p. 246) in 1888. This authority described his specimens
as a distinct species, naming it L. vaillant:. (I shall show later that the
two are identical.) He observed also the male and female heteronereids,
of which he gave excellent and detailed descriptions, with a number of
figures.
Thenceforward, L. glauca was not met with so far as has been recorded,
until 1909, when Major Elwes found his specimen, a male heteronereid,
at Oddicombe.
In 1878, however, Langerhans (5, p. 279) had described under the name-
of Leonnates pusillus another small species of nereid which, as I hope to
show, is very closely related to, if not identical with, the one under
consideration. This species he found at Madeira, and he observed in
an aquarium the change to the heteronereid form in both sexes.
LEPTONEREIS GLAUCA CLPDE. AND GENUS LEPTONEREIS KINBERG. 245
There can be little doubt that Leptonereis must occur commonly in
many localities on the shores of this country and of the Continent in
which its presence is not suspected, either for lack of observers or on
account of its small size.
GENUS LEPTONEREIS KINBERG, CHAR. EMEND.
Proboscis furnished only with soft papille.
The notopodium and neuropodium rather deeply divided.
In the male heteronereid, the body is divided into three distinct
regions, the middle region only being modified for swimming, while the
posterior is marked by the appearance of peculiar fused sete, not present
in the nereid-form or in the female heteronereid.
Characters otherwise as in Nerezs Lin.
LEPTONEREIS GLAUCA Claparéde, Plate I, Figs. 1-10.
Leptonereis glauca Claparéde, 3, p. 90, Pl. 7, Figs. 3-3c.
vaillanti de St. Joseph, 6, p. 246, Pl. 10, Figs. 113-123 ;
Pl. 11, Fig. 124.
vaillanti Elwes, 8, p. 351.
‘e vaillanti McIntosh, 8, p. 264, Pl. 86, Figs. 9-9a.
? Leonnates pusillus Langerhans, 5, p. 279.
2)
39
This little nereid occurs in some numbers on the piles of the wharf at
the Great Western Docks. These are exposed at low water, and are
covered with compound ascidians, sponges, various ccelenterates and
other sedentary organisms, which, together with the muddy sediment
which accumulates in such places, form a thick encrustation on the
cement piles and wallings near low-water mark. In these congenial
surroundings Leptonereis dwells. It also occurs in dredgings from Asia
Shoal and the Cattewater, in the former of which localities the bottom
consists of stones and mud, in the latter of soft mud.
Its small size and the resulting difficulty of distinguishing it from other
small nereids, no doubt account for its having been hitherto overlooked.
The short cephalic lobe, stout squat palpi, and short tentacles, peris-
tomial and parapodial cirri, and peristomium, serve to distinguish it
—once its appearance is known—from Nerevs pelagica, small examples of
which occur in the same localities, but for certainty the parapodia and
proboscis must be examined under the microscope.
Several dozens of specimens in all were collected, and a number of
these were examined in detail, as a basis for the following description.
246 ° LL, N. G. RAMSAY,
The length of the individuals ranges from 7 mm. to 35 mm., but the
majority are about 25 mm. long.
As to colour, I examined live specimens from all three localities, and
these were practically colourless, except for blood-vessels and gut show-
ing through the semi-transparent body-wall. In examination some
months later, however, some specimens (preserved in alcohol) show a
slight band of brownish granular pigment across the dorsum of each seg-
ment, becoming more marked towards the posterior end of the animal.
This band of pigment is more or less continuous with glands which occur
on the base of the parapods, rather like those of N. dumeriliz.*
Specimens of average size have 55 to 60 pairs of parapods ; the greatest
number noted was 66, the smallest, in a specimen barely 9 mm. long,
30 pairs.
The body is fairly stout, tapering gradually towards the posterior end.
There is a tendency towards shortness in all the appendages. The general
form will best be realized by a glance at the figures, which are taken from
typical specimens (Plate I, Fig. 1).
These worms, when placed in spirit, usually die with the proboscis
retracted, but I succeeded in preventing its retraction in about a dozen
specimens, obtained during my stay at Plymouth, by means of a pin
pressed behind the head while spirit was poured over the creature. (This
immensely facilitates the examination of small nereids.) The proboscis
is short and stout ; the maxillary division is quite smooth, but the basal
division possesses on the ventral side a row of 5 to 9 minute, soft, conical
papille, perfectly colourless, in a transverse, even-spaced row towards
the anterior margin. These correspond in position to paragnaths of
groups VII, VIII. On the dorsal surface of the basal division a single
larger papilla of similar nature (corresponding to VI) exists on each side.
These papille are small and very inconspicuous. It is very difficult to
distinguish them at all except when seen in profile, or when the light upon
them falls at a suitable angle. Fig. 1 shows in profile the two outer
papille of the ventral row.
Neither Claparéde nor de St. Joseph observed any trace of such papille
in the specimens from Naples and Dinard, but the Plymouth examples
agree so completely otherwise with those, that one is inclined to
* Later, in December, 1913, Mr. Orton kindly sent to me at Cambridge a number of
living specimens from the Great Western Docks. In the living state these were of a dull
orange tint over most of the body, due to the internal organs showing through the trans-
parent body-wall. Towards the anterior end there was a slight dull greenish pigmenta-
tion of the skin, strongest on the head and adjacent segments, but hardly noticeable in
most specimens. This pigment is shown up more clearly just after fixation when the body
has become opaque.
LEPTONEREIS GLAUCA CLPDE. AND GENUS LEPTONEREIS KINBERG. 247
think that the papille must have escaped observation in the other
cases.
Their presence, of course, rather upsets the characterisation of the
genus, which has hitherto been based solely on the total absence of
paragnaths or papillee !
A remarkable feature was exhibited by a number of specimens col-
lected on 20th March. These bore on the proboscis four patches of a
jet-black colour, radiating outwards from the bases of the jaws, in the
everted proboscis, towards the areas where groups II and IV of the
paragnaths would, if present, occur. These black marks appeared to
consist of a deposit of opaque pigment beneath the cuticle. Fig. 1 is
taken from a typical specimen, and shows the two dorsal patches. Of
twelve specimens collected on this date, eight showed these patches
strongly developed, while the remainder exhibited no trace of them.
The black marks were still present when the specimens were re-examined
after lying for some weeks in alcohol and formol, but by October, 1913,
all traces of them had disappeared. Fortunately, however, one specimen
had been mounted in balsam at the earlier date, and in this (the specimen
figured) the black is perfectly preserved. Further investigation of its
- nature is desirable. The only other specimens which I examined in a
fresh state had the proboscis inverted ; the rest of the material had been
lying in spirit for some months.*
The parapodia of Leptonereis have been described in detail by St.
Joseph, but I have thought it useful to figure these again, as they are
the chief means of identification. (St. Joseph’s figures are rather
grotesque.f) They do not differ from the typical nereis-form of parapod
except in that their noto- and neuropodia are more deeply and widely
separated than usual. They are approximately similar from end to end
of the body. The noto-cirri are rather short, usually slightly over-
reaching the ligule; a slight increase in relative length of the cirri
usually takes place in the posterior half of the body.
The sete, which have been figured by Claparéde, St. Joseph, and
McIntosh, have the typical nereid arrangement, thus :—
Notopodial bundle, homogomph spinigers.
Upper neuropodial Fanalel Lompacm DE eee poe):
| heterogomph falcigers (below).
Lower neuropodial bundle seas aa eee moNer
| heterogomph falcigers (below).
* The everted probosces of more than a dozen of the living specimens received in
December, 1913, showed on examination no trace of these black patches.
+ Claparéde’s single figure of a parapod is also unnatural.
248 L. N. G. RAMSAY,
St. Joseph (6, p. 247) notes that from the 13th to the 4th last segment,
the spinigers of the notopodial bundle are replaced by others, similar, but
with a much longer terminal appendage. This appears to be the case,
too, in some at least of the Plymouth specimens, although the change
seems to occur posterior to the 13th segment. I have not paid much
attention to this point. He also states that homogomph as well as
heterogomph spinigers occur in the lower neuropodial bundle. This I
have not found to be the case.
Among the material collected by Mr. Orton on 25th February is a
male heteronereis, apparently in the fully developed condition, and two
other males at earlier stages of development.
St. Joseph (6) has described both the male and female heteronereid
forms in detail. Claparéde did not meet with either.
The above-mentioned male agrees very well with St. Joseph’s descrip-
tion. It is 12°5 mm. long, with 58 pairs of parapodia. The noto-cirri of
the first seven pairs of parapodia are much swollen (Fig. 7). The change
to the swimming-parapod occurs between the 14th and 15th pairs (St.
Joseph found it to occur between the 15th and 16th pairs—the variation
is unimportant). In the 43rd to 45th pairs a transition towards the form
of the third region occurs, the cirriand lobes becoming shorter and smaller,
and the paddle-setz decreasing in number.
The third region may be reckoned as commencing at the 44th pair,
where the peculiar, large, simple setz, figured by St. Joseph, commence.
These are from one to three in number, and continue till the last setigerous
segment. They are, I believe, to be regarded simply as derived from
normal heterogomph falcigers by the fusion of the appendage with its
socket. Ground for this belief is afforded by the analogy of the large
bristles which occur in the posterior regions of Neres pelagica and
N. agassizt. In these the appendages are in some cases completely free,
in others totally fused with the shaft.
Several females of the nereis-form, obtained on 20th March, were filled
with ova. These are of very large relative size (0°24 mm. diameter).
The synonymy at the head of this section requires some ex-
planation.
St. Joseph in his detailed and excellent account of Leptonereis vaillanti
never refers to the possibility of this species being identical with Clapa-
réde’s. He does not indicate any points of difference between the two
species, and indeed, the only mention he makes of L. glauca is to
say that the sete of vaillanti are exactly similar to those figured by
Claparéde for the Mediterranean form.
LEPTONEREIS GLAUCA CLPDE. AND GENUS LEPTONEREIS KINBERG. 249
Comparison of the descriptions and figures published by these two
authors leaves us with the following points of difference :—
(a) The Dinard specimens differ slightly in colour.
(b) Their noto-cirri are shorter.
The general form of the head and its appendages, the proboscis and
jaws, the peristomial cirri, the parapodia (except for the noto-cirri), the
sete, the dimensions of the whole animal and number of segments—all
are identical in the two.
As to the points of difference, (a) hardly amounts to more than the
fact that the Mediterranean specimens were more strongly pigmented
than those from Dinard. The Plymouth ones, it appears, are still
less so.
Then coming to (6) one may note that the noto-cirri of the Plymouth
specimens are almost intermediate between those of St. Joseph’s and
those of Claparéde’s. It does not seem that much importance should be
attached to this point.
Secondly, I have come to the conclusion that Langerhans’ Leonnates
pusillus from Madeira is at least very closely related to Claparéde’s
Leptonereis glauca. Langerhans’ description and figures leave no doubt
that the two species are of the same genus (in view of the presence of
papillee on the proboscis to Leptonereis). In Leonnates pusillus a papilla
is present in area II on each side, in addition to those on the basal ring
(these are only visible “bei sehr genauem Zusehen’’). Also the peri-
stomial segment apparently was distinctly longer than in Leptonerevs
glauca. Many examples showed a large yellow spot on the cephalic lobe ;
this, however, was not always present.
In other respects Leonnates pusillus is identical with Leptonereis glauca.
Langerhans kept some specimens in captivity for some time and wit-
nessed the change to the heteronereid form, in both male and female.
His observations on these agree essentially with St. Joseph's. The
large, brown sete appeared in the same way in the posterior eleven pairs
of parapodia of the male.
Langerhans concludes his description of this species with the sugges-
tion that an examination of fresh material will show that in species such
as Leptonereis glauca and L. cebuensis the proboscis is furnished with
papille similar to those of Leonnates pusillus. After a lapse of thirty-
five years his prediction has been fulfilled.
250 L. N. G. RAMSAY.
HISTORY AND SYSTEMATIC POSITION OF THE GENUS.
Kinberg (2, p. 179), in 1865, “ created ”’ the family Niconidea to con-
tain those nereids in which the proboscis is devoid of papille, whether
hard (paragnaths) or soft.
This family contained three genera, distinguished thus :—
uniform. 5 : . Neon.
Parapodia . (gradually. ; . Leptonereis.
| changing abruptly (with 3 changes) . Nuicomedes.
In these three genera he enumerated eight species, all new to science,
from the east and west coasts of South America, and from Tahiti. None
of these species is described in sufficient detail to be recognisable, and
only one is figured [(1, Taf. XX, Fig. 7), Leptonereis levis, n.sp., from
Guayaquil].
Claparéde (3, p. 90) united Kinberg’s three genera under the name of
Leptonereis, which he ranked as a sub-genus of Nerezs, Linn. s. str. He
chose the name Leptonereis on account of its convenience as a sub-generic
name, and because it was the only one of the three genera which Kinberg
had figured.
Claparéde did not further characterise Leptonereis, but apparently
simply accepted Kinberg’s definition of the “‘ family ” Niconidea, namely,
total absence of paragnaths or papille from the proboscis. Further he
described Nereis (Leptonereis) glauca, a new species of which he appar-
ently found several specimens in the Gulf of Naples, although in his
‘‘ Annélides Chétopodes du Golfe de Naples”’ he gives absolutely no
information as to its occurrence or habitat. He also figured the head
and anterior segments, proboscis, a parapod, and sete (most of his
figures are good, although a little “ artificial ”’ in appearance).
In 1878 Grube described L. cebuensis from the Philippine Islands, and
in the same year Langerhans published his account of Leonnates pusillus.
Ten years later St. Joseph brought out his account of the annelids of the
coasts of Dinard.
Grube and St. Joseph both followed Claparéde in regarding Leptonereis
as a sub-genus of Nerezs, but McIntosh ranks it as a separate genus,
differing from Nerezs Lin. in the absence of paragnaths and in the deeply
divided rami of the parapodia.
My own view, based on the examination of a large amount of material
in all the groups of the genus Nerezs, and in Leonnates and Leptonereis,
is that the last-named should be ranked as a genus distinct from both
LEPTONEREIS GLAUCA CLPDE. AND GENUS LEPTONEREIS KINBERG. 251
the others. These three genera are, however, more closely related to one
another than to any of the remaining genera of Nereide (i.e. Lycastis,
Ceratocephale, Tylorrhynchus, Dendronereis, and Micronereis).
SURVEY OF THE GENUS LEPTONEREIS.
For generic characters (emended) see above, p. 245.
1. LepTronEREIS GLAUCA Claparéde, 1870.
L. vaillanti, de St. Joseph, 6.
Range: English Channel.
2. LEPTONEREIS PUSILLUS Langerhans, 1878.
Leonnates pusillus Langerhans, 5.
Very closely allied to the preceding species, if not identical (see above,
p. 249).
Range: Madeira.
3. LEPTONEREIS CEBUENSIS Grube, 1878.
Grube’s description of this species is unfortunately not accompanied
by any figures.
Range: Philippine Islands.
4. LEPTONEREIS L&VIS Kinberg, 1865.
This species must remain rather uncertain, as Kinberg’s description
is very brief. The figures of anterior region and proboscis, a para-
podium, and the sete, are fairly good. The palps and tentacular cirri
are longer than in L. glauca.
Range : Guayaquil (Ecuador).
[Kinberg did not figure any of the other seven species which he
described under the genera Nicon and Nicomedes, and his descriptions are
so brief as to be of little value for purposes of identification. The only one
of these which has been met with again is Nicon loxechini, from the
Straits of Magellan. In this case Ehlers has employed the name Nereis
loxechini Kinberg for a species of which a single small specimen was
collected by the German Deep-Sea Expedition at St. Paul Island (38° 40’
S., 77° 38’ E.), in the southern Indian Ocean. Ehlers unfortunately does
not figure this specimen, nor does he describe it fully, so that there is
considerable doubt as to whether it should be assigned to the genus
Leptonereis. The Nereis eugene Kinberg of Ehlers, although founded
on Kinberg’s Nicon eugenie, is a true Nereis. |
252
OL
L. N. G. RAMSAY.
BIBLIOGRAPHY OF THE GENUS LEPTONEREIS.
KinpereG, J. G. H. Fregatten Eugenies Resa, Zool. VII. Annulater.
Stockholm, 1865. (Republished 1910.)
Krnpere, J. G. H. “ Annulata Nova,” Ofvers. K. Vet-Akad. Forh., 1865.
CLAPAREDE, EH. “ Annélides Chétopodes du Golfe de Naples, Suppl.”
Mém. Soc. de Phys. et @ Hist. Nat. de Geneve, T. XX, 1870.
GruBE, E. “ Annulata Semperiana.” Mém. Ac. Imp. Sci. de St.
Pétersbourg, VITe Ser., T. XXV, No. 8, 1878.
LancerHans, P. ‘“ Die Wurmfauna von Madeira, II.” Zeitschr. f.
Wiss. Zool., XX XIII, 1878.
Sr. JosEpH, Baron DE. “‘ Annélides Chétopodes des Cotes de Dinard ”
(pte. 11.). Ann. des Scr. Nat. (7°), V, 1888.
Enters, E. “‘ Bodensissigen Anneliden,” Wass. Ergebn. des Deutschen
Tiefsee-Exp., Bd. XVI, Lfg.i., Jena, 1908.
8. Enwes, E. V. “ Littoral Polycheta of Torquay.” Journ. Mar. Biol.
Ass., VIII, 1909.
McIntosu, W.C. ‘The British Annelids.”” The Ray Scciety, London,
1910, Vol. II, pt. i1.
EXPLANATION OF PLATE.
Leptonereis glauca Clap. Plymouth, 1913.
. 1. Anterior region, with proboscis extended, x 23.
2. Posterior extremity (from above), x 23.
Fies. 3-5. Parapodia of immature form.
3. 2nd R., anterior view, x 25.
4, 12th L., anterior view, x 25.
5. 34th L., anterior view (total 59 pairs), x 25.
6. 41st L. (@ nereid with ova), anterior view (total about 60 pairs),
x 25.
Figs. 7-10. Male Heteronereis.
7. 5th R., posterior view, x 35.
8. 30th R., anterior view, x47.
9. 48th R., posterior view (total 58 pairs), x 35.
0. Neuropodium from the posterior region, showing one of the large
fused sete half-grown, not as yet projecting from the para-
podium (posterior view), < 145.
Prarceis
L. N. G. RAMSAY. LEPTONEREIS GLAUCA.
L.N.G.R. DEL.
[ 253 ]
[ 254 ]
On the Breeding Habits of Echinus miliaris, with a
Note on the Feeding Habits of Pate//a vulgata.
By
J. H. Orton, B.Sc., A.R.C.Sc.
With One Figure in the Text.
WHILE on shore-collecting expeditions in this district it was frequently
observed that Echinus miliaris has the habit of associating together in
pairs, and sometimes in groups of more than two.* The association of
these pairs and groups is sometimes so intimate that it 1s not possible
to interpose even the blade of a penknife between the interlocking
spines of the urchins. In all cases observed except one, such pairs were
placed side by side, but in one particular case the apical region of one
individual was almost certainly placed adjacent to the apical portion of
the other. In all the collecting expeditions{—made at various times of
the year between April and August—on which groups were collected,
the total number of urchins of all sizes obtained amounts to about 710.
Among this number were obtained 84 groups, which amount in all to
189 specimens. In the earlier part of the investigation a group was
taken as such if the members were merely fairly close together, but
afterwards only those specimens were recorded which were actually
touching one another in the manner described above. Out of the total
of 84 groups only 27 were actually recorded definitely as touching one
another, although some of the other groups may have been touching.
Of these 27 closely associated forms all the individuals were ripe except
3 small specimens belonging to two pairs which were recorded as having
an immature gonad. The remainder consisted of 19 pairs 9 9, 2 pairs
29, 1 pair 5 3, and 3 groups respectively $29,t 3 SQ, and $29.
These facts in themselves point to the conclusion that in #. miliaris
* In a few cases as many as from 13 to 21 individuals have been found close together
under one stone.
+ In the search for groups of these urchins I am much indebted to the laboratory
fisherman, William Searle, for the zeal and care with which he helped in the collecting.
In this group the ? associated with the male was almost certainly spent, although it
was difficult to make certain whether on the other hand it might be immature. Hence it
is not grouped with the definite pairs of male and female.
ON THE BREEDING HABITS OF ECHINUS MILIARIS. 255
there is a distinct instinct for association of individuals at the time of
sexual maturity, and that the association frequently, but not always,
results in pairing of the sexes. In this respect the position in which two
of the above pairs of male and female were taken is specially interesting.
Both pairs were situated under a large stone whose lower surface was
somewhat rectangular, and would measure rather more than two feet
on the longer axis. The pairs were on the opposite ends of the lower
surface near the edge of the stone on the long axis, and each member of
a pair was closely opposed to the other. It would thus appear that these
four urchins had definitely mated in pairs.
Of the 57 remaining groups taken, 41 contained all ripe individuals,
and combining these 41 groups with those given above, it was found
that out of the total of 66 associations of ripe specimens, 41 were 3 Q,
9 of various sexes, 899, 6 3g, and 2999. Thus in all the groups of
ripe forms there were 40 pairs of opposite sexes and 8+6+2=16 groups
exclusively of one sex or the other. Therefore, leaving out the 9 groups
containing various sexes, it is seen that the number of pairs, namely 41,
is greater than twice the number of the groups which contain one sex
or the other. Consequently it is highly probable that the statement
that the sexes of EZ. miliaris associate definitely for the purpose of breeding
is significant.
In the whole of the groups collected, regardless of ripeness of the
gonad in all the members of the group, there were 47 pairs of 3 and 9,
15 pairs 292, 6 3 3, 8 groups of more than two containing both sexes,
2 groups 222, 1 93, and 5 containing one or more immature forms.
In the groups recorded as not all ripe there were some specimens quite
ripe. Many of the other urchins in these groups, however, would probably
have yielded some embryos if their sex cells had been mixed with those
from similar forms of the opposite sex, but an attempt based on experi-
ence was made to name those forms ripe which would probably have
yielded a good proportion of segmenting eggs as a result of fertilization.
In this branch of the investigation I am indebted to Mr. H. M. Fuchs
for some help in determinmg the state of the gonad.
A more significant result could doubtless be obtained by an examina-
tion of a larger number of pairs of E. miliaris obtained about the same
time and during the breeding season, but the opportunities for such an
investigation are not very common. HF. miliaris can often be taken in
numbers by dredging, and then I have frequently observed that many
individuals are taken matted together, and in such a way as to suggest
they were actually in that condition before being captured by the dredge.
256 J. H. ORTON.
In the same way large hauls of H. esculentus and E. acutus and relatively*
large hau!s of Lchinocardium cordatum can frequently be made on certain
grounds in hauls of not more than 10 to 15 minutes, but it is equally
uncertain here, as in the case of the dredged H. miliaris, that there is
any association in pairs; nevertheless it is not improbable that the
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Fic. 1.+—A view of Patella showing the food-paths it has eaten in a growth of green alge,
chiefly young Enteromorpha (2 natural size),
The limpet is shown on its ‘‘home,” from which it has made excursions in
various directions and to which it has afterwards returned.
ageregation of such large numbers of individuals might be in part for
the purpose of spawning, since such hauls may be taken when all these
species are ripe.
Tennent has observed in Toxopneustes that “ when these animals are
* Echinocardium cordatum when living in deep water inhabits fine sand, from which it
can only be captured by means of a dredge, and in a 3-foot dredge a short haul may some-
times yield as many as 15 individuals. This species occurs in great numbers in the
Salcombe estuary within a very small area, but this aggregation is probably due more to
the presence of only a small area of suitable ground than to a desire of the individuals to
associate. Nevertheless in this locality these heart-urchins associate closely in groups of
twos, threes, and sometimes in larger numbers. The sexes of the members of such groups
have not, however, been observed.
+ Iam indebted to Mrs. Orton for the drawing for this figure, which has been copied
from a sketch made in my collecting book.
~ D. H. Tennent, Journ. Exp. Zool., Vol. IX, No. 4, p. 659, 1910.
ON THE BREEDING HABITS OF ECHINUS MILIARIS 257
ready to spawn they gather more or less closely together,’ and Hertwig*
mentions that ‘‘ ege-deposition may provide sexual stimulation to the
males, since when a large number of urchins are placed together in sea-
water as soon as the females begin to discharge eggs the males spawn.”
It is not improbable, therefore, that association of the sexes for the
purpose of spawning may be common throughout the Echinoids.
Nore on THE FEEDING Hapits oF PATELLA.
It is well known that Patella obtains its food by browsing on both
the smaller and larger forms of alge.f Striking evidence of this fact has,
however, been obtained and is worth noting. In observing specimens of
Patella situated on cement piles above low-water mark, it was noticed
that the animals had in many cases eaten away paths in the green alge,
chiefly young Enteromorpha, by which they were surrounded. The paths
radiate from the “ scar”’ of the animal, and are marked with fine lines
made by the teeth on the radula. These paths are shown in Fig. 1.
In several cases the animal had travelled beyond the end of the path
formerly eaten before beginning to browse again, and afterwards re-
turned home to its scar. (See Fig. 1.) Such configurations as that
shown in the figure are by no means uncommon on the pier walls in this
district in situations favourable for the growth of alge. As the alga
grows the food-paths of the limpet may become more marked, and in
some cases the spatting of Balanus balanoides along the paths makes
them so evident that they are easily seen from some distance away.
* O. Hertwig, Zeit. fiir Wiss. Zool. Jen., Vol. XXIV, p. 282, 1890.
+ J. R. Ainsworth Davis and H. J. Fleure, Patella L.M.B.C. Memoir, Vol. X,
London, 1903.
On the Occurrence of Aphroceras (Leucandra) cliarensis
Stephens near Plymouth.
By
Arthur Dendy, D.Sc., F.R.S.
In July, 1912, a paper was published in the Proceedings of the Royal
Trish Academy (Vol. XXXI) on the Marine Porifera of Clare Island, by
Miss Jane Stephens, in which the authoress gives an excellent account of
a new species of Calcareous Sponge, Leucandra cliarensis. In April of
the same year I happened to be working at the Marine Laboratory at
Plymouth, and my friend Mr. Orton brought me several specimens of a
very pretty little calcareous sponge just collected by him at Wembury
Bay. I was too much occupied with other work to examine these care-
fully at the time, but simply preserved them im spirit. Recently I have
examined them in detail, and find, curiously enough, that they belong
to the species described by Miss Stephens from Clare Island on the
west coast of Ireland.
It is unnecessary, in view of the description already published by Miss
Stephens, to give a detailed account of the sponge in this place. I may,
however, point out the salient features by which it is easily recognized.
The external appearance is characteristic. The individuals are usually
solitary and less than an inch in height. The form of the sponge, how-
ever, varies greatly, from quite slender to almost globular. There is
usually a single terminal vent. The surface, when viewed under a
pocket-lens, exhibits a glistening appearance, with longitudinal striations
due to the presence of gigantic oxea in the dermal cortex. This arrange-
ment of the large oxea brings about a close resemblance to species of the
genus Ute. The canal system is, however, typically leuconoid, with
small, rounded flagellate characters.
The most remarkable and constant specific character appears to be
the presence of enormous sabre-shaped apical rays on the gastral quadri-
radiates, sometimes reaching a length of 0-5 mm., and, of course, pro-
jecting into the gastral cavity.
In our recently published paper on “ The Classification and Phylogeny
ON THE OCCURRENCE OF APHROCERAS (LEUCANDRA) CLIARENSIS. 259
of the Caleareous Sponges, etc.” (Proc. Zool. Soc. Lond., Sept., 1913)
Mr. Row and I have placed the species in the genus Aphroceras Gray,
which is distinguished from Leucandra by the presence of a dermal
layer of gigantic longitudinal oxea. This genus cannot, however, be
very sharply separated from Leucandra, and in A. cliarensis a great many
of the large oxea lie obliquely in the deeper parts of the sponge, as in
many Leucandras. Nevertheless, there are sufficient of the large oxea
in the dermal layer to give the surface of the sponge the longitudinally
striated (and not obviously hispid) character of Aphroceras.
The discovery of this interesting species at Plymouth contributes an
interesting addition to the marine fauna, not only of the district, but
also of Great Britain ; while the fact that it should have turned up there
so shortly before the appearance of Miss Stephens’ memoir is one of
those curious coincidences which so frequently surprise the systematic
zoologist. .
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914, R
[ 260 ]
Note on Two Unrecorded Plumularian Hydroids
from the Plymouth Area.
By
James Ritchie, M.A., D.Sc.,
Royal Scottish Museum, Edinburgh.
ConFuSION has reigned in the works of British authors as to the relation-
ship between Plumularia catharina, Johns., and a more simple form,
with unbranched stem, found, like the former, on many parts of the
coast. Johnston and Hincks, and the majority of their successors, have
recorded the simple form, where it was thought worthy of mention, as
a “stemless variety’ of the former; but examination of the type
specimens of P. catharina in the British Museum has proved that a
fundamental distinction exists between the two forms.* P. catharina
is a branched species and bears on each side of a hydrotheca a pair of
lateral sarcothece ; the other is a branchless, bristle-like form, bears on
each side of a hydrotheca a single lateral sarcotheca, and has been long
known as Antenella (or Plumularia) secundaria (Gmelin).
One of the most common of Plumularias in the Plymouth area, in a
wide sense, is P. catharina, and in a recent papert Mr. Crawshay records
the “‘creeping variety’ from many stations in the Outer Western Area
of the English Channel, with the remarks that it occurred over the whole
area, and that it was perhaps the most frequent of the two varieties,.
and was certainly the most flourishing in point of growth.
I have had the opportunity, thanks to Mr. Crawshay, of examining
a few samples of the simple form, and find that it embraces two distinct:
species, which are different from P. catharina, and have not been recorded
from the area. The most common of these is Antenella secundaria
(Gmelin), distinguished by a simple stem, and by details of hydrotheca
structure exceedingly like those of the erroneous figure of P. catharina
given by Hincks in “ British Hydroid Zoophytes,’ Plate LVI, Fig. 2a.
It was found at Duke Rock in August, 1895, and was dredged in the
* See Ritchie, ‘‘ Note on the Type Specimens of Plumularia catharina,” etc., Proc.
Roy. Physical Soc., Edinburgh, Vol. XIX, 1913, p. 1.
+ Crawshay, Journ. Marine Biol. Association, Vol. IX, 1912, pp. 279 and 330.
NOTE ON TWO UNRECORDED PLUMULARIAN HYDROIDS. 261
Outer Western Area of the Channel at Station 37 (S. 41° W. of Eddystone
at distance of 17-1 miles) in 1906.
The other species is Antenella siliquosa (Hincks), described by Hincks,
from St. Peter’s Port, Guernsey, in 1877,* and since recorded from only
two areas: from 8.W. of Toulon at a depth of 445 metres, and in
the neighbourhood of Roscoff on the N.E. corner of France between
60 to 80 metres (Billard, 1907 and 1912). To these localities Plymouth
material adds two more records, both in the Outer Western Area of the
Channel. A few colonies were obtained from Station 80, 8. 163° W. of
Eddystone, 48°9 miles distant, at a depth of 51 fathoms; and a larger
clump was dredged during Cruise VII at an undefined position between
S. 17° to 27° W. of the Eddystone, at a depth between 49 and 53 fathoms.
The two species may be readily distinguished. Both have simple
unbranched stems. A. secundaria closely resembles P. catharina in the
details of structure, but has only one sarcotheca flanking each hydro-
theca, in place of a pair; A. siliqguosa has a wider and larger hydro-
theca, but its distinctive feature les in the lateral sarcothece, which
occur one on each side of a hydrotheca, and have the even margin of the
terminal section interrupted by a large wide embayment, a condition
not recorded from any other species of Antenella.
* Ann. Mag. Nat. Hist., ser. 4, Vol. XIX, 1877, p. 148, Pl. 12, Figs. 2-6.
On Alcyonium pulmonis instar lobatum Ellis.
By
R. Hartmeyer, Berlin.
With one Figure in the Text.
In the year 1755 Ellis described in his “Natural History of
the Corallines,”’ as “Alcyonium pulmonis instar lobatum,’ a “sea
production” from Whitstable, which the fishermen there had
brought to him under the name of “Sea-Fig.” As regards the system-
atic position of this form, he expresses himself only in so far as to place
it with the Aleyonians, a group in which were united at that time,
along with true species of Aleyonium, Ascidians, Hydroids, Sponges and
even Algz. As a doubtful synonym of his species Ellis put forward
the Pulmo marinus of Rondelet (1555), which however has nothing
whatever to do with it and indeed cannot be certainly determined.
During the following years, Ellis’ work was translated into several
languages. A Dutch and a French translation, both dating from the
year 1756, are known to me, the former by Tak, the latter by
Allamand. There is also a German translation by Krtiniz dated 1767.
Before I proceed with the history of this species it appears to me
advisable first of all to define it, so as to be able in the further course
of the discussion to deal with a fixed systematic conception. The
description and the figures which Ellis gives are so characteristic that
the “ Aleyonium pulionis instar lobatum” can only be identified as a
compound Ascidian. As such the species was recognised, as soon as
ever the close relationship of the colony-forming ascidians, which had
previously been regarded as Aleyonians, to the simple ascidians was
determined, that is to say about the year 1816. It is remarkable
however that the form has never since been the subject of a thorough
description, although it is mentioned in many textbooks and handbooks,
as well as in faunistic papers, during the following 30 or 40 years. In
more recent literature the species receives scanty mention, mostly only
as a list name or as an uncertain species, whilst it has practically
entirely disappeared from the most modern literature.
My wish to clear up if possible once for all this form by the
examination of typical local examples has now been carried out through
ON ALCYONIUM PULMONIS INSTAR LOBATUM ELLIS. 263
the kindness of Dr. Allen. I received three colonies sent by him,
which had been collected by fishermen at West Mersea, Essex, that
is to say in a locality which from a faunistic standpoint can hardly be
different from the neighbourhood of Whitstable. Especially valuable
to me was however the accompanying information that the name
“ Sea-Fig ” has been retained there down to the present day. We have
therefore every right to suppose that these specimens from West
Merseaare the same species as the “Aleyoniwm pulmonis instar lobatum”
of Ellis.
An examination of these three colonies has yielded a result which I
had previously anticipated: Ellis’ species is no other than the well-
established Macroclinum pomum (Sars), which is frequently mentioned
in the most recent literature and is everywhere common in the North
Fig. 1.—Macroclinum pulmonaria (Ell. Sol.). Colony from West Mersea. Natural size.
Sea. This supposition must have already forced itself upon the mind
of anyone acquainted with the species, when reading E]1is’ description,
a model of its kind, and comparing it with his figures. After the
direct proof of the occurrence of Macroclinum pomum on the Essex
coast no further doubt of the identity of the two forms would seem to
be possible.
Of the three colonies before me from West Mersea, the largest has
a typical fig-lhke shape. The anterior end is broadened, the posterior
end is tapered and runs out into a quite short, stem-like process,
which serves for its attachment. The colony is strongly compressed
laterally. Its length is 7-9 em., its greatest breadth 5:1 cm., whilst its
thickness never exceeds 1:1 cm. The colour is greenish grey. The
systems are not very clearly recognisable, but are undoubtedly present.
The whole habitus of the colony with the separate individuals shining
through like yellow seeds, is very aptly characterised by the descrip-
264 R. HARTMEYER.
tion “Sea-Fig.” A second colony is considerably smaller. The length
is only 3-4 cin., the breadth 2°7 cm. The posterior end is less strongly
tapered, the remaining characters are on the other hand the same.
Finally the third colony forms only a small cushion on a sponge.
So much as to the material in hand and the identity of Ellis’ form
with the Macroclinum pomum of recent literature. In order to establish
the synonomy and the correct specific name I will now proceed to the
history of the species, which is specially complicated by the fact that
in the old literature for many decades the species was confused with a
sponge, which to-day in sponge-nomenclature bears the name Ficulina
Jicus (Pall.). Ellis and Solander (1786) first pointed out this error,
and Esper (1806) also recognised it, but Lamarck (1815) was the
first and after him Lamouroux (1816) to distinguish the two species
by special binomial names.
Ellis’ “ Aleyonium pulmonis instar lobatum” reappeared for the first
time in the literature in Pallas, in his “Elenchus Zoophytorum”
of the year 1766, and indeed as a synonym of Aleyonium ficus.
The specific name jicvs was here for the first time used in a binomial
combination with the generic name Aleyoniwm, so that Pallas must
be regarded as the author of that species which must bear the name
jicus. The following extracts from the literature relating to the
synonymy of Aleyonium ficus are quoted verbally :—
(1) Alcyonium tuberosum forma ficus. Imper. ital. p. 599 lat. p. 839.
Only the Italian edition of the “ Historia naturale” of
Francesco Imperato dated 1599 has been available to me.
A form is there described and figured on p. 734, under the
name “ Alcyonio tuberoso in forma di fico frutio: Aleyono
quinto di Dioscoride,” which is without doubt a sponge and
has been identified by the spongiologists as Piculina ficus, I
do not know whether the page reference given in the Italian
edition, namely page 599 in Pallas, is due to an error, or
whether it refers to some other edition. A date of publica-
tion for Pallas is not given. Moreover the same page
reference is found in Esper. In the latter’s work the
quotation from Imperato (Esper writes Imperati) reads:
“ Aleyonium tuberosum forma Ficus: Haleyoneum quintum
Dioscoridis.” I will take this opportunity of mentioning that
the “ Alcyonio quinto di Dioscoride” quoted from Jmperato is
mentioned in his Materia medica of the year 1478 as
“ Alcyonii quinta species.” A determination of this form is
hardly possible.
ON ALCYONIUM PULMONIS INSTAR LOBATUM ELLIS. 265
(2) Aleyonium tuberosum. J. Bauh, hist. III p. 817. In the
“Historia Plantarum universalis” of Joh. Bauhin and
Joh. Henr. Cherler dated 1651 there is in v. 3 lib. 39 p. 817
a copy of the figure from Imperato, with the description
Alcyonium tuberosum. This reference also must be assigned
to the sponge.
(3) Ficus substantia inter Spongiam et Aleyonium medie. Marsil.
hist. mar. p. 87 tab. 16 n. 79. This reference is to the
“Histoire physique de la Mer” by L. F. Marsilli dated
1725. The passage there reads exactly: “ Figue de substance
@Eponge & ad Aleion, nommée par Trionfetti, Aleyonium
tuberosum, forma ficus Imperati.” The coasts of Barbary are
given as locality. This reference also, as may be seen from
the figure, t. 16, f. 79, without doubt has to do with a sponge
and Ficulina ficus is indicated. A copy of this figure is to be
found also in Esper (1806).
(4) Aleyonium quintum antiquorum. Mercat. metall. arm. 6. ¢. 6.
p. 102. In his “Metallotheca Vaticana” dated 1717
Mercati describes, under the title “De quinto antiquorum
alcyonio,” a form which is also a sponge and must be regarded
as a synonym of Ficulina jficus. The figure bears the legend
“ Alcyonium quintum.”
(5) Pulmo marinus alter Rondeletii. Raj. syn. p. 31, n. 3. In the
3rd Edition of his “Synopsis methodica Stirpium
Britannicarum” dated 1724, J. Ray puts forward the
Pulmo iarinus alter Rondel. as a synonym for bursa
marina.—Rondelet’s species cannot be determined. The
Bursa marina is on the other hand an Alga. The reference
from Ray does not therefore come into consideration either
in connection with the sponge or the ascidian. In the first
edition of this work dated 1690, which Lendenfeld (1896)
quotes, I do not find “ Pulmo marinus” mentioned.
Some references, also relating to the sponge, which are lacking in
the list of synonyms in Pallas, should now be added. In the first
place a reference which is to be found in Bonanni, in his “Museum
Kircherianum” dating from 1709 and reads: “ Aliud Alcionum ex
Mari Adriatico acceptum visitur, quod Tuberosum vocavit Imperatus.”
Further the “ Alcionio minore in figura di fico frutto” mentioned and
figured by Ginanni (1757) in his “Opere postume,” v.1 p. 41
t. 47 £98. Finally the “Aleyonium tuberosum Ficus forma Imp.” men-
tioned by Battarra ina new edition of the “Museum Kircherianum”
dated 1773, p. 179 (note).
266 R. HARTMEYER.
The next author after Pallas is Linneus. In the 12th and also
in the 13th Edition of the “Systema Nature” he records an
Aleyonium (Aleionivm) Ficus with the same synonymy as Pallas.
This literature reference is thus also a partial synonym of both species.
The Dutch translation of Pallas’ Elench. Zooph. by Boddeert (1768),
Houttuyn’s edition (1772) of Linneus’ Syst. Nat. ed. 12, St. Miiller’s
German edition (1775) of the same work, and an extract from Miiller’s
edition by Héslin (1782) give nothing new.
The Alcyonium Ficus,which Berkenhout mentions in the “Outlines
of the natural History of Great Britain and Ireland” dated 1769,
refers to Ellis’ form, and is therefore exclusively a synonym of the
Ascidian. The species appears again later in both editions of the
“Synopsis of the natural History of Great Britain and
Ireland” by the same author dated 1789 and 1795, which constitute
the 2nd and 3rd editions of the “ Outlines.”
To Ellis and Solander belongs the credit of having pointed out for
the first time in their “History of Zoophytes,” in the year 1786, the
specific difference between the sponge and the ascidian. The ascidian
originally called “Sea-Fig” by Ellis received the name “ Aleyoniwm
Pulmonaria,” without however the authors having recognised its
ascidian nature. For the determination of the correct specific name
this reference is however of decisive significance, for here the Aleyoniwm
jicus was for the first time divided into two species, of which the one
(the ascidian) received the new specific name “ pulmonaria,” whilst the
other (the sponge) retained the original specific name “j/icus.” Ellis
and Solander refer to the mistaken union of the two species in the
following words :—“ This name of Sea-Fig [of Ellis] has occasioned a
mistake in some late authors, who have confounded it with the Sea-
Fig of Count Marsigli, which is a true sponge.”
The following years yield a series of literature references, which
either cannot be accurately determined or in which both species are
again confounded. To the latter class belong the Alcyoniwm Ficus in
the translation of Pallas’ Elench. Zooph. by Wilkens and Herbst
(1787), the Alcyonium Ficus which Meuschen records in the
“Museum Geversianum” (1789), the Alcyonium ficus of Bruguiere
in the “Encyclopédie méthodique” (1787), the Alcyoniwm Ficus in
Gmelin’s edition of the “Systema nature” (1791) and in the
English edition of this work by Turton (1806).
Not decisively to be indicated are the Alcyonium Ficus, which Olivi
(1792) recorded from the Gulf of Venice, and the Alceyonium ficus,
which Cuvier (1798) mentions in his “Tableau ¢lémentaire” with-
out literature reference or locality. The first of these cannot, owing
ON ALCYONIUM PULMONIS INSTAR LOBATUM ELLIS. 267
to the locality where it was found, be referred to the ascidian. Whether
both references belong to the sponge must remain undetermined.
To the sponge must be assigned the Aleyoniwm Ficus, which Poiret
records ineshis “Voyage en Barbarie” of the year 1789. To the
ascidian on the other hand the Alcyoniwm ficus of Bose mentioned in
his “Histoire naturelle des Vers” (1802). In the second edition
of that work of the year 1827 Bosc has however again combined the
two species, since he here, in addition to the reference to Ellis, gives
also as a synonym the A. Ficus of Lamouroux (1816), which refers
to the sponge.
The Aleyonium ficus, which Borowski and Herbst figure in their
“Naturgeschichte des Thierreichs” (1787) is a copy of Ellis’
figure. In the text however no literature is referred to and the locality
is given as the Mediterranean. In the synonymy of the ascidian there-
fore only the reference to the figure can be accepted.
Esper then again separated the two species in his large work on the
“Pflanzenthiere.” What he describes as Alceyoniwm Ficus is the
sponge, whilst the ascidian is left without a binomial designation. In
Esper there is also to be found a careful summary of the literature.
In his “British Fauna” of the year 1807 Turton records an
Aleyonium Ficas [sic !], which must be ranked as the ascidian.
Then in the years 1815 and 1816 there follow the important works
of Lamarck and Lamouroux, which treat of both species under
binomial names. Nevertheless the true nature of the two species was
still not recognised, and they were both left in the genus Aleyoniwm.
For the sponge Lamarck introduced the new but superfluous name
Aleyonium ficiforme. The Mediterranean was given as locality. For
the ascidian on the other hand the name Aleyoniwm pulmonaria,
originating from Ellis and Solander, was applied, and as localities the
Atlantic Ocean and the Channel were given.
Lamouroux in his “Histoire des Polypiers coralligénes
flexibles,” dated 1816, also retains for the ascidian the name
Aleyonium Pulmonaria, whilst for the sponge he uses the correct
nomenclature, that is to say the specific name Aleyoniwm Ficus.
By the important work of Savigny of the year 1816, it was con-
clusively proved that the colony-building Ascidians, which until then
had been placed with the alcyonians and polyps, ought to be united to
the simple ascidians. Thus Ellis’ form took its place definitely
amongst the ascidians, and Savigny indeed placed it in the new genus
Aplidium, which he then founded. He only made a mistake in the
choice of the specific name, since he called the species Aplidiwm ficus,
instead of employing the name pulmonaria given to it by Ellis and
268 R. HARTMEYER.
Solander. The consequence of this mistake is that the specific name
jicus has been retained until the present day in the ascidian literature,
but has also been used at the same time by writers on sponges. I have
already shown that the name jicus cannot be maintained for an
ascidian, but must fall to the sponge. Savigny does not discuss the
sponge further.
Another new name for the ascidian was introduced in the same year
by Lamarck in his “Histoire naturelle des Animaux sans
Vertébres.” Although he recognises the genus Aplidiwm founded by
Savigny, he calls the species Aplidium sublobatum. Why he should
introduce this new specific name, although he had in the year 1815 de-
signated the species Alcyoniwm pulmonaria, is not very easy to see.
Moreover he retains the sponge in the genus Alcyoniwm and keeps the
name A. ficiforme.
The year 1816 therefore fixes the time from whence onwards the two
species finally remain separate. Ellis’ form is recognised as ascidian,
whilst it is not until many years later that Alcyoniuwm jicus is regarded
as a sponge and placed first in the genus Suwberites, later in Hali-
chondria, finally in the genus Ficulina, which was established specially
for this species. With this definite separation of the two species only
the further history of the ascidian will continue to interest us here,
but before proceeding, I should like to consider briefly Lendenfeld’s
paper on the “Clavulina der Adria” published in 1896. A sum-
mary of the literature on Ficulina ficus is given in this paper, which
contains some errors in the old references previous to the year 1816, which
may be here corrected. In the first place there is placed amongst the
synonyms the Aleyonium pulmonis instar lobatum of Ellis. I can only
suppose that Lendenfeld had no personal acquaintance with Ellis’
work, or he would never have regarded the figure which Ellis gives as
that of a sponge. As the earliest literature reference Bauhin and
Cherler, 1651 (not 1650!) are quoted. This is not correct. Bauhin
and Cherler indeed are based on Imperato and even give an extract
from the work of the latter. I have already referred to the reference
to Ray (1690), which also contains an error. A further mistake,
finally, is that Lendenfeld ascribes the authorship of the name /ficus
to Linneus instead of to Pallas.
I now proceed with the history of the ascidian. After Savigny’s
species had been placed, in the year 1816, in his genus Aplidiwi, as
Aplidium ficus, the specific name jicus was prevalent for 30 years.
Only in quite isolated instances the synonymous specific name swblo-
batum, derived from Lamarck, appeared along with it. On the other hand
the generic name was changed repeatedly. This is explained by the fact
ON ALCYONIUM PULMONIS INSTAR LOBATUM ELLIS. 269
that Savigny’s genera were toa large extent again united by later authors.
Thus our species appears sometimes as Polyclinum ficus, sometimes as
Synoteum ficus, sometimes as Pulmonellum jficus, in isolated instances
indeed still as Alcyoniwm jicus. It would take us too far to discuss this
literature in detail. I must content myself with pointing out here
only the most important facts in the history of the species. It will be
best first of all to follow, up to recent times, the specific name /icus,
which predominated in the older literature till about the year 1850.
The older works belonging to the first half of the last century, in
which the species is referred to, are without exception in the nature
of compilations, and bring nothing new to our knowledge of the
species. To this category belong the references by Cuvier (1817),
Goldfuss (1820), Fleming (1820, 22), Schinz (1822), Fleming
(1824), Lamouroux (1824), Blainville (1824, 25, 27), Fleming
(1828), Stark (1828), Rang (1829), Blainville (1829, 30), Cuvier
(18350), Voigt (1834), Blainville (1854), Oken (1835), Cuvier (1836),
Blainville (1837), Fleming (1837), Dujardin (1837, 40), Gervais
(1840), Comte (1840) (under the name Distoma variolatus this author
gives a copy of Ellis’ figure), Reichenbach (1842), Deshayes (1842),
Poeppig (1848), Forbes and Hanley (1848) also do not know
the species from their own observation, but quote from Ellis. From
the second half of last century the following references, belonging to
the same category should be mentioned: Wright (1855), Gosse
(1856), H. and A. Adams (1858), M‘Andrew (1861), Granger (1886),
Herdman (1891), Lameere (1895), Maitland (1897), and finally also
Hartmeyer (1909).
The following works contain some remarks on the species, in some
cases only records of new localities :—
Alder and Hancock (1848) mention an Aplidium ficus from
Cullercoats, but leave the identification uncertain. The record of
locality had better therefore for the present remain doubtful, although
it is not unlikely that the species occurs there.
Cocks (1850) records in his list of the Ascidians of Falmouth
an Aplidiwm ficus. The identification cannot be tested. That the
species occurs on the south coast of England I consider doubtful, until
the contrary is proved. At any rate I have not found it amongst the
extensive collection from Plymouth which I have examined. This
locality therefore may for the present remain doubtful.
Gervais and P. J. Beneden (1859) give the North Sea as a
locality. P. J. Beneden (1860) records the occurrence of Aplidiwm
jicus in deep water on the Belgian coast in company with a second
species which he calls Aplidium ficoides. Details of the anatomy
270 R. HARTMEYER.
are not given however, but it seems possible to decide with certainty
from the external characters alone that it refers to our species.
Aplidium ficoides is probably only a synonym. I have recently had in
my hands many colonies which were also collected off the Belgian
coast, so that the occurrence of the species there is certain.
Ansted and Latham also record Aplidiwm jficus in a list of the
Ascidians of the ChannelIslands. This statement cannot be tested.
I have myself not seen any example of this species from the Channel
Islands, although I have identified a great deal of ascidian material
from that locality. It appears however by no means improbable that
the species occurs there, probably in deeper water. I come to that
conclusion because Giard (1873) also mentions a Polyclinum ficus
from the neighbouring coast of Granville, which he identifies as
Ellis’ species. I do not doubt that this P. jicus of Giard is the same
as our species. Giard thinks it probable that the species lives in deep
water and is only occasionally thrown on the shore. That would also
explain the fact that the species is mentioned neither by Milne-
Edwards nor by Lahille, and consequently we may conclude that it
does not occur within the limits of the true littoral zone on the north
coast of France.
Pelseneer (1892) mentions the species from Blankenberghe,
where it is frequently taken by the fishermen; Bizet (1892) from the
coast of Somme. It seems to me however questionable whether in
the latter case our species is really concerned, possibly there is a con-
fusion with Glossoforum sabulosum. Sharp (1911) mentions the species
again from the Channel Islands (Cobo). The same remarks apply to
this record as to that of Ansted and Latham. Finally in the
posthumous work of Alder and Hancock (1912) published by
Hopkinson a numerous collection of references to this species is to
be found, in which however references which belong to the sponge are
erroneously included. In other respects this work furnishes nothing
new. .
An Aplidium or Polyclinum ficus is also repeatedly recorded from
the Mediterranean. Thus by Martens (1824), Grube (1864), Faber
(1883), and Carus (1890); Targioni-Tozzetti (1880) mentions an
Aplidium sublobatum. In all these cases there is a mistaken identifica-
tion, since our species does not occur in the Mediterranean. Probably
in most cases the form dealt with is Amaroucium pyramidale (Brug.)
(Syn. A. conicwm (Olivi)).
It is interesting to follow how in the course of years the specific
name ficus disappears more and more from the literature. Up to the
middle of the last century one misses it in hardly a single general
ON ALCYONIUM PULMONIS INSTAR LOBATUM ELLIS. 271
work on ascidians. In the fifties and sixties also it is still somewhat
frequently mentioned. After that the name becomes constantly less
frequent and in the most recent times it has as good as completely
disappeared from the literature. But although in the older literature
the species was recorded so very frequently, no author has given us an
anatomical description sufficient to enable us to place the species with
certainty in the present system. For in order to recognise the form,
as Giard does, as Polyclinum, the proof must first be forthcoming that
it actually agrees with the genus Polyclinum in the arrangement of
the intestinal loop, the most important generic character of that genus.
For such a proof one seeks im vain in the whole literature of the
species. The form has remained, one may rather say, problematical
as regards its systematic position up to the present day. By the re-
examination of typical, local specimens this question is now solved.
The identity of the Alcyoniwm pulmonis instar lobatum of Ellis with the
frequently mentioned Macroclinum pomum (Sars) of recent literature
has been established.
The latter species was first described by Sars (1851) as Amarouciwm
pomum, and was placed later by Huitfeldt-Kaas (1896) in the genus
Aplidiopsis founded by Lahille; together with a newly described species
A. sarsu. Hartmeyer (1903) then recognised the near relationship of
these two species to Macroclinum crater, described by Verrill (1871),
from the Newfoundland Banks, which was the type of the new
genus Macroclinum, Aplidiopsis sarsii was explained as a synonym of
M. crater, whilst A. pomum was placed as an independent species in the
genus Macroclinum. Bjerkan (1905) afterwards showed that J. crater
and JZ. pomum were alsosynonyms, and that the species should bear the
latter name. This name has been retained until the present day.
Now the name pomwm has to be replaced by the older name pu/mo-
naria, so that the species must now be called Macroclinum pulmonaria
(Ell. Sol.). Naturally the position of the species as type of the genus
Macroclinum remains unaffected by this change of name.
In conclusion I add a list of the most important references to
Ficulina ficus (Pall.) up to the year 1816, as well as of the whole litera-
ture on Macroclinim pulmonaria (Ell. Sol.) as far as it is known to me
FICULINA FICUS (Patt.).
1478 “ Alcionii quinta species,” Dioscorides, Materia medica, lib. 5 cap. 90.
1599 “ Aleyonio tuberoso in forma di fico, frutto: Aleyonio quinto di Dios-
coride,” Imperato, Stor. nat., p. 734 f.
1651 “ Aleyonium tuberosum,” Bauhin & Cherler, Hist. Plant. univ., v. 3
lib. 39 p. 817 f.
ale R. HARTMEYER.
RTOS" Alcronum. ... %; quod Tuberosum vocavit Imperatus,” Bonanni,
Mus. Kircher., p. 267.
1717 “ Alcyonium quintum” (quintum antiquorum alecyonium), Mercati,
Metallotheca Vatic., p. 102 f.
1725 “ Figue de substance d’Eponge § dAlcion, nommée par Trionfetti,
Alcyonium tuberosum, forma jficus Imperati,” Marsilli, Hist. phys.
Mer, poe? t.16f 72:
1757 “ Aletonio minore in figura di fico frutto,” Ginanni, Oper. post., v. 1
p. 41 t. 47 f. 98.
1766 Alcyonium Ficus (part.), Pallas, Elench. Zooph., p. 356.
1767 Alcyonium Ficus (part.), Linné, Syst. Nat., ed. 12 ». 1 IT p. 1299.
1767 Alcionium Ficus (part.), Linné, Syst. Nat., ed. 13 v, 1 II p. 1295.
1773 “ Aleyonium tuberosum Ficus forma Imp.,” Battarra in: Bonanni,
Mus. Kircher., p. 178, 179 nota.
1786 ‘ Sea-Fiy,” Ellis & Solander, Zooph., p. 206 t. 59 f. 4.
1789 Aleyonium Ficus, Poiret, Voy. Barbarie, v. 2 p, 57.
1791 Aleyonium Ficus (part.), Gmelin, Syst. Nat., v. 1 VI p. 3813.
11792 Alcyonium Ficus, Olivi, Zool. Adriat., p. 240.
11798 Aleyonium jicus, G. Cuvier, Tabl. élém., p. 682.
1806 Alcyonium ficus, Esper, Pflanzenth., pars 3 fasc. 2 (14) p. 63 t. Ale.
20 f. 1-4.
1815 Alcyonium ficiforme, Lamarck in: Mém. Mus. Paris, v. 1 p. 75.
1816 Aleyonium ficiforme, Lamarck, Hist. An. s. Vert., v. 2 p. 394.
1816 Alcyonium Ficus, Lamouroux, Hist. Polyp., p. 348.
1896 Ficulina jicus, Lendenfeld in: N. Acta Ac. Leop., v. 69 nr. 1 p. 94.
MACROCLINUM PULMONARIA (Ett. Sot.).
1755 Alcyonium pulmonis instar lobatum, Ellis, Corallin., p. 82 t. 17 £. b,
B, C, D. non bin.
1756 Alcyonium pulmonis instar lobatum, Tak, Ellis Koraal-Gewass., p. 89
t. 17 f. b, B, C, D. non bin. [Dutch translation of Ellis, Corallin. ]
1756 Aleyonium pulmonis instar lobatum, Allamand, Ellis, Corallin., p. 97
t. 17 f. b, B, C, D. non bin. [French translation of Ellis, Corallin. ]
1766 Alcyontwm Ficus (part.), Pallas, Elench. Zooph., p. 356.
1767 Alcyonium Ficus (part.), Linné, Syst. Nat., ed. 12 v. 1 IT p. 1295.
1767 Aleionium Ficus (part.), Linné, Syst. Nat., ed. 13 v. 1 IL p. 1295.
1767 Aleyonium pulmonis instar lobatum, Kriiniz, Ellis, Corall-Art., p. 89
t. 17 f. b, B, C, D. non bin. [German translation of Ellis, Corallin.]
1768 Alcyonium jficus (part.), Boddert, Plant-Dier., p. 442 t. 11 f. 3.
[Dutch translation of Pallas, Elench. Zooph. |.
1769 Alcyonium Ficus, Berkenhout, Outl. Hist. Great Brit., v. 1. p. 210.
1772 Alcyonium Ficus (part.), Houttuyn, Natural. Hist., pars 1 v. 17 p. 398.
[Dutch translation of Linné, Syst. Nat., ed. 12.]
1775 Aleyonium ficus (part.), St. Miiller, Natursyst. Linné, v. 6 II p. 787.
[German translation of Linné, Syst. Nat., ed. 12.]
1782 Aleyonium jficus (part.), Hislin, Linné, Natur-Syst., v. 2 p. 608.
ON ALCYONIUM PULMONIS INSTAR LOBATUM KLLIS. 273
1786 Aleyontum Pulmonaria, Ellis & Solander, Zooph., p. 175.
1787 Alcyonium Ficus (part.), Meuschen, Mus Gevers., p. 532.
1787 Aleyonium Ficus (part.), Wilkens &J.F.W. Herbst, Pallas Thierpfi.,
v. 2p. 121 t. 18 f. 63. [German translation of Pallas, Elench. Zooph. |
1787 Alcyonium jficus, J. ¥. W. Herbst in: Borowski & J. F. W. Herbst,
Naturg. Thierr., atl. v, 9 t. 65 f. 1 a, b.
(non 1787 Alcyontum jficus, J. F. W. Herbst in: Borowski & J. F. W.
Herbst, Naturg. Thierr., v. 10 p. 77.)
1789 Aleyonium Ficus, Berkenhout, Synops. Hist. Great Brit., ed. 2 v. 1
p-. 213.
1789 Aleyonium ficus (part.), Bruguiére in: Enc. méth., Vers v. 1 p. 26.
1791 Alcyonium Ficus (part.), Gmelin, Syst. Nat., v. 1 VI p. 3813.
1795 Aleyonium Ficus, Berkenhout, Synops. Hist. Great Brit., ed. 3 v. 1
p- 213.
1802 Alcyonium jicus, Bose, Hist. Vers, v. 3 p. 133.
1806 Aleyonium Ficus (part.), Turton, Syst. Nat. Gmelin, v. 4 p. 653. [Eng-
lish edition of Gmelin, Syst. Nat.]
1806 Aleyonium Ficus (part.), Esper, Pflanzenth., v. 3 fasc. 2 (14) t. Ale.
20 f. 5-8. .
1807 Alcyonium Ficas (err.), Turton, Brit. Fauna, v. 1 p. 207.
1815 Aleyonium pulmonaria, Lamarck in: Mém. Mus. Paris, v. 1 p. 76.
1816 Aleyoniwm Pulmonaria, Lamouroux, Hist. Polyp., p. 342.
1816 Aplidium sublobatum, Lamarck, Hist. An. s. Vert., v. 3 p. 95.
1816 Aplidium jficus, Savigny, Mém. An. s. Vert., v. 2 p. 183.
1817 Polyclinum ficus, G. Cuvier, Régne an., v. 2 p. 501.
1817 Alcyonium ficus, Anonym in: Enc. Brit., ed. 5 v. 10 p. 358.
1820 Polyclinum jficus, Goldfuss, Handb. Zool., v. 1 p. 591.
1820 Alpidium (err.) ficus, J. Fleming in: Edinb. Ene., v. 14 p. 631.
1821 Aplidium jficus, Lamouroux, Expos. Polyp., p. 74.
1822 Aplidium (err.) ficus, J. Fleming, Phil. Zool., v. 2 p. 514.
1822 Polyclinum Ficus, Schinz, Thierr. Cuvier, v. 2 p. 781.
1824 Aplidium jicus, Lamouroux in: Ene. méth., Zooph. p. 75.
1824 Synoicum Ficus, Blainville in: Dict. Sci. nat., v. 32 p. 367.
1824 Alpidium (err.) ficus, J. Fleming in: Ene. Brit., ed. 4, 5, 6 suppl.
v. 5 p. 083.
(non 1824 Polyclinum ficus, G. Martens, Reise Venedig, v. 2 p. 480.)
1825 Synoicum Ficus, Blainville, Man. Malac., p. 587 t. 82 f. 6, 6a, 6b.
1827 Synoicum ficus, Blainville in: Dict. Sci. nat., v. 51 p. 484.
1827 Alcyonium ficus (part.), Bosc, Hist. Vers, ed. 2 v. 3 p. 160.
1828 Alpidium (err.) ficus, J. Fleming, Hist. Brit. An., p. 470.
1828 Aplidium sublobatum, Stark, El. nat. Hist., v. 2 p. 121.
1829 Synoieum jicus, Rang, Man. Moll., p. 355.
1830 Pulmonellum jficus, Blainville in: Dict. Sci. nat., v. 60 p. 489.
[1816-1830] “ Synoique sublobé” [Synoicum fieus], Blainville in: Dict.
Sci. nat., pl. Zool. Conchyl. t. 113 f. 6, 6a.
1830 Polyclinum ficus,G. Cuvier, Regne an., ed. 2 v. 3 p. 169
274 R. HARTMEYER.
1834 Polyclinum Ficus, F. S. Voigt, Thierr. Cuvier, v. 3 p. 596.
1834 Pulmonellum jficus, Blainville, Man. Actin., p. 526.
1835 Alcyonium jicus, Oken, Allg. Naturg., v. 5 I p. 93.
1836 Polyclinum ficus, G. Cuvier, Regne an., ed. 3 v. 2 p. 105.
[1837] Pulmonella ficus, Blainville, Man. Actin., p. 683.
1837 Alpidium (err.) ficus, J. Fleming in: Ene. Brit., ed. 7 v. 15 p. 370;
Moll..An., p. 213.
1837 Aplidium sublobatum, Dujardin in: Lamarck, Hist. An. s. Vert., ed. 3
Q.1 poo710.
1840 Aplidium sublobatum, Dujardin in: Lamarck, Hist. An. s. Vert., ed. 2
v. 3 p. 489.
1840 Aplydium (err.) ficus, Gervais in: Dict. Sci. nat., suppl. v. 1 p. 410.
[1840] Distoma Variolatus (part.) + Synoicum Ficus, Comte, Régne an., t. 28 f.
1842 Polyclinum Ficus, Reichenbach, Conchil., p. 125.
[1842] Polyclinum jicus, Deshayes in: Cuvier, Régne an. [ed. 4], Moll.
p. 245.
1848 Aplydium (err.) ficus, Poeppig, Naturg. Thierr, v. 4 p. 223 f. 3945 a, b.
1848 Aplidium jicus, Alder & Hancock in: Tr. Tyneside Club, v. 1
p. 203.
1848 Aplidium jicus, E. Forbes in: E. Forbes & Hanley, Brit. Moll, v. 1
Darlek.
11850 Aplidium jicus, Cocks in: Rep. Cornwall Soc., 1849 p. 73.
1851 Amaroucium pomum, M. Sars in: Nyt. Mag. Naturv., v. 6 p. 155.
1855 Aplidium jicus, Wright in: Nat. Hist. Rev., v. 2 Proc. p. 70.
1856 Aplidium jyicus, Gosse, Man. mar. Zool., v. 2 p. 32.
1858 Aplidium jficus+ Amouroucium pomum, H. & A. Adams, Gen. Moll.
p. 600, 601.
1859 Amaroucium pomum, M. Sars in: Forh. Selsk. Christian., 1858 p. 66.
1859 Aplydium (err.) ficus, Gervais & P. J. Beneden, Zool. méd., v. 2,
p. 74.
1860 Aplidium jicus, P. J. Beneden in: Bull. Ac. Belgique, ser. 2 v. 9
p. 154.
1861 Aplidium jficus, McAndrew in: Rep. Brit. Ass., v. 30 p. 222.
21862 Aplidium jficus, Ansted & Latham, Chann. Isl., p. 219.
1863 Amaroecium (err.) pomum, Alder in: Ann, nat. Hist., ser. 3 v. 11
p> Lio;
(non 1864 Aplidium jficus, Grube, Lussin, p. 58.)
1865 Polyclinum sp., Alder in: Nat. Hist. Tr. Northumb., v. 1 p. 11.
1871 Macroclinum crater, A. E. Verrill in: Amer. J. Sci. ser. 3 v. 1
p- 293 f. 23-25.
1872 Macroclinum crater, A. E. Verrill in: Amer. J. Sci. ser. 3 v. 3
p- 212.
1873 Polyclinum ficus, Giard in: Arch. Zool. expér., v. 2 p. 493.
i879 Macroclinum crater, A. E. Verrill, Check. L. mar. Invert., p. 27.
(non 1880 Aplidium sublobatum, Targioni-Tozzetti, Espos. Pesca Berlino,
cat, ital. p. 137.)
ON ALCYONIUM PULMONIS INSTAR LOBATUM ELLIS. PAP a
1882 Aplydium (err.) jicus, Pelseneer in: Ann. Soc. malac. Belgique, v.
Lin py 40.
{non 1883 Polyclinum jficus, G. L. Faber, Fish. Adriatic, p. 251.)
1886 Aplidium ficus, Granger in: Hist. nat. France, v. 7 p. 206.
{non 1890 Aplidium ficus, J. V. Carus, Prodr. F. Medit., v. 2 p. 483.)
1891 Polyclinum ficus, Herdman in: J. Linn. Soc. London, v. 23 p. 619.
1891 Amaroucium pomum, Herdman in: J. Linn. Soc. London, v. 23 p. 628.
1891 Macroclinum crater, Herdman in: J. Linn. Soc. London, v. 23 p. 628.
11892 Aplidium ficus, Bizet in: Mém. Soc. Nord France, v. 8 p. 389.
1893 Amaroucitum pomum, Herdman in: Ann. nat. Hist., ser. 6 v. 12
p. 445.
1895 Polyclinum jficus, Lameere, Man, Faune Belgique, p. 42 f. 5.
1896 Aplidiopsis pomum, Huitfeldt-Kaas in: Norske Nordhavs-Exp., v. 7
ser. 23 I p. 13 t. 1 f. 8-10.
1896 Aplidiopsis sarsti, Huitfeldt-Kaas in: Norske Nordhavs-Exp., v. 7
ser. 23 I p. 14 t. 1 f. 11-13.
1897 Amaroucium pomum, Norman, Mus. Norman., cat. LX p. 6.
1897 Aplidium ficus, Maitland, Prodr. Faune Pays-Bas, p. 34.
1903 Macroclinum crater, Hartmeyer in: Fauna arctica, v. 3 p. 319 t. 6
fO-5: Golo LG, ts
1903 Macroclinum pomum, Hartmeyer in: Faune arctica, v. 3 p. 322.
1905 Macroclinum pomum, Bjerkan in: Bergens Mus. Aarbog, 1905 nr. 5
perdi
1906 Macroclinum pomum, Hartmeyerin: Wiss. Meeresunters, v. 8 p. 126.
1907 Macroclinum crater, Redikorzew in: Annuaire Mus. St.-Peétersb.,
v1 p; 148, 153.
1908 Macroclinum pomum, Bjerkan in: Tromsé Mus, Aarsh., nr, 25 p. 88.
1909 Polyclinum jficus, Hartmeyer in: Bronn’s Kl. Ordn., v. 3 suppl.
p- 1461, 1481.
1909 Macroclinum pomum, Hartmeyer in: Bronn’s KI. Ordn., v. 3 suppl.
p. 1464.
1909 Aplidium sublobatum, Hartmeyer in: Bronn’s Kl. Ordn., v. 3 suppl.
p. 1469.
1910 Macroclinum pomum, Hartmeyer in: Bronn’s KI. Ordn., v. 3 suppl.
p. 1584 nota.
1910 Macroclinum pomum, Van Name in: P. Boston Soc., v. 34 p. 396
f. 21 t. 38 f. 8.
1910 Macroclinum pomum, Redikorzew in: Trav. Soc. St.-Pétersb., v. 41
fasc. 2 p. 156 f. 42.
1911 Macroclinum pomum, Redikorzew & Hartmeyer in: Derjugin in:
Trav. Soc. St.-Pétersb., v. 42 fasc. 1 nr. 1-2 p. 24.
1911 Polyclinum jficus, W. E. Sharp in: Rep. Guernsey Soc., 1910 p. 207.
1912 Amaroucium pomum, Alder & Hancock, Brit. Tun., v. 3 p. 16.
1912 Aplidium ficus, Alder & Hancock, Brit. Tun., v. 3 p. 23, 101
f. 97-99.
1912 Macroclinum pomum, Hartmeyer in: Vid. Meddel., v. 63 p. 280.
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914. s
276 R. HARTMEYER.
DISTRIBUTION.
ENGLAND anD ScottanD: Moray Firth (Alder 1863)—? Cullercoats (Alder
and Hancock 1848)—West Mersea—Sheerness (Berkenhout 1769)
— Whitstable (Ellis 1755)—1? Falmouth (Bream Bay ; Helford River)
(Cocks 1850).
ENGLISH CHANNEL: (Lamarck 1815)—(Granger 1886).
CHANNEL Istanps: Guernsey (Ansted and Latham 1862)—Cobo (Sharp 1911).
Norta Coast or France: Granville (Giard 1873)—Somme (Bizet 1892).
Brexeran Coast: (Beneden 1860)—Blankenberghe (Pelseneer 1882).
Norto Sea: (Gervais and Beneden 1859)—Heligoland (Hartmeyer 1906)—
Dogger Bank (Alder 1865; Hartmeyer 1906)—Great Fisher Bank
(Hartmeyer 1906)—56° 1’ N. 4° 49’ E,, 38 m.—S.W. Lindesnaes,
57° 2’ N. 4° 3’ E., 64 m.—57° 11’ N. 0°11 E., 78 m— 57° 41’ N.
5° 35° H., 100 m.—57° 20’ N. 8° 2’ E., 57 m. (Bjerkan 1905). *
ScaNDINAVIA AND DenmarRK: Baadsfjord (E.-Finmark), 65 m. (Bjerkan 1905)
—Gyjesver (Bjerkan 1908)—Havésund, 72 m. (Sars 1851)—Tromso,
54-72 m. (Hartmeyer 1903)—-Tromsdsund, 40-100 m. (Bjerkan
1908)—Ure, Lofoten, 36 m. (Sars 1851)—Vestfjord near Bodo, 105-
160 m.—Trondhjemsfjord : Skarnsund, 150-200 m.; off Tautra, ca.
200 m.; off Rodberg, ca. 300 m. (Hartmeyer 1912); Rédberg
(Herdman 1893)—Hessefjord, near Aalesund, 90 m. (Bjerkan 1905)
— Bohuslin — Beian — Christiansund (Huitfeldt-Kaas 1896) —
Hellebaek (Mus. Berlin) *—Grosser Belt (Mus. Berlin). +
Murman Coast: Kola Fjord (Redikorzew and Hartmeyer 1911).
SPITZBERGEN : Stor Fjord, 77° 8’ N. 20° E., 155 m. (Redikorzew 1907).
Far6e Istanps: North point of Nolso, ca. 180 m. (Hartmeyer 1912)—East
of Fardes, 62° 16’ N. 6° 6’ W., 110 m. (Bjerkan 1905).
Icrnanp: S.E. coast of Iceland, 64° 17’ N. 14° 44’ W., 75 m. (Bjerkan 1905).
GREENLAND: S. of Cape Farewell (Hartmeyer 1910).
Norta East America: Newfoundland (Verrill 1871; Hartmeyer 1903; Van
Name 1912)—Virgin. Rock, 72 m. (Van Name 1912).
Macroclinum pulmonaria is a decided sub-arctic species, which is distributed
right across the North Atlantic from the east coast of North America to the
Murman coast. On the American side it has only been found in Newfound-
land. In the eastern part of the North Atlantic its most southerly locality is
the north coast of France (Granville) and the Channel. It has not yet how-
ever certainly been proved to occur on the south coast of England, nor has it
been found in the Ivish Sea, on the Irish coasts, nor on the west coast of Scotland.
On the other hand it is known from various points on the east coasts of
* Also collected at many other places in the North Sea during the quarterly cruises of
the Poseidon and of the Heligoland fishery research vessels during the years 1902-5.
+ The Berlin Museum possesses in each case one small colony of this species from
Hellebaek, Gundel leg., and from the Greater Belt, collected during the Pommerania
expedition. Both localities are new.
ON ALCYONIUM PULMONIS INSTAR LOBATUM ELLIS. QE
Scotland and England. From the Channel it extends along the Belgian coast
and through the whole North Sea, where it appears to be very abundant every-
where, enters Danish waters (Greater Belt), and then follows the whole west coast
of Sandinavia by Lofoten and Finmark to the Murman coast. Here its most
easterly locality is the Kola Fjord. Towards the north it spreads through the
Farée Islands and Iceland to the neighbourhood of Cape Farewell on the one
side and the Stor Fjord (Spitzbergen) on the other. Only at these two points
does it go within the Arctic Circle, and it seems always to remain in the
neighbourhood of the warmer currents. The whole area of distribution
extends therefore from west to east from 48° W. to 34° E., from south te
north from 48° 50’ N. to 77° 8’ N., or through 82 degrees of longitude and 29
degrees of latitude.
The species generally prefers deeper water. The vertical distribution lies,
as far as the records show, between 38 and 300 metres. A decided littoral
form the species is certainly not. In the Channel it appears to occur only in
deeper water, and is absent from the coastal zone. In many places it is
clearly extraordinarily abundant, as for example in the North Sea, especially
in the neighbourhood of the Dogger Bank and the Great Fisher Bank. The
species appears to live chiefly on sandy ground.
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Verrill, A. E., Descriptions of some imperfectly known and new Ascidians
from New England. In: Amer. I. Sci., ser. 3 v. 1 p. 54-58, 93-
100, 211-12, 288-94, 443-46 f. 1-26. New Haven. 1871.
—-—-, Recent Additions to the Molluscan Fauna of New England and the
adjacent waters, with notes on other species. In: Amer. J. Sci., ser. 3
v. 3 p. 209-14. New Haven. 1872.
—w—., Preliminary Check-List of the marine Invertebrata of the Atlantic
Coast, from Cape Cod to the Gulf of St. Lawrence. New Haven.
1879.
Voigt, F. S., Das Thierreich. . . . Von Cuvier. Nach der ed. 2 iibersetzt
. von F. 8. Voigt. v. 1-6. Leipzig. 1831-43.
Wickens, Chr. F. & Herbst, J. F. W., P. S. Pallas, Charakteristik der Thier-
pflanzen, worin von den Gattungen derselben allgemeine Entwiirfe
und von denen dazugehoérigen Arten kurze Beschreibungen gegeben
werden. . . . Aus dem Lateinischen iibersetzt. . . . von Christian
Friedrich Wickens, und. . . . Johann Friedrich Wilhelm Herbst,
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y
[ 283 ]
On Ciliary Mechanisms in Brachiopods and some Poly-
cheetes, with a Comparison of the Ciliary Mechanisms
on the Gills of Molluscs, Protochordata, Brachiopods,
and Cryptocephalous Polychetes, and an Account of
the Endostyle of Crepidula and its Allies.
By
J. H. Orton, B.Sc., A.R.C.Sc.
With twelve Figures in the Text.
TABLE OF CONTENTS.
PAGE
Introduction : 283
Ciliary mechanisms pr adneine the main fad ond ashen ere in pea honode 284
Ciliary mechanisms on the gill-filaments and lophophore ; : ; . 5 PASI
The ciliation of the gill-filaments of Brachiopods : : 293
Summary of current-producing mechanisms and the mode of fcenings in Br nelsonods 294
An explanation of some morphological characters in fossil and recent Brachiopods 295
Comparison of the ciliary mechanisms on the gills of Gastropods, Lamellibranchs,
Amphioxus, and Brachiopods . 297
The ciliary mechanisms on the gills of Ger iocepbalons Baeenetes oad on the
lophophore of Phoronis . : : : : F : . 301
The endostyle of Crepidula and Cites 5 . 303
Comparison of the adaptations in Brachiopods and Tarmeliipranohe fo the ieee
of feeding : : ; : : : : , : : ‘ . 307
Summary. : : : ; : : ‘ : : 3 : . 308
INTRODUCTION.
THE results of the writer’s investigations on the ciliary mechanisms on
the gills of Mollusca and Amphioxus (1 and 2) gave rise to the suggestion
that similar mechanisms might probably also occur in Brachiopods, for
it is a well-known fact that Brachiopods—like some Molluscs and Am-
phioxus—feed on the smaller organisms which are to be found floating
in the sea. Owing to the kindness of Dr. H. C. Williamson, of Aberdeen,
I have been able to examine living Crania which were obtained by dredg-
ing in Loch Fyne, and living Terebratula have also been obtained from
Naples. An investigation of the living gill-filaments—or lophophoral cirri,
as they are frequently termed in this group—showed that the ciliary
284 J. H. ORTON.
mechanisms on these filaments are essentially the same as those occurring
on the gill-filaments cf Amphioxus, Lamellibranchs, some Gastropods,
and most Ascidians. As it was found that existing accounts of the
mode of feeding in Brachiopods are vague and incomplete the following
description of the process has been written.
The nutritive currents in Brachiopods were the subject of an investi-
gation by J. Hérouard (3) as early as 1877. This writer conceived the
ingenious plan of investigating these currents by constructing artificial
lophophores of lead piping perforated in places corresponding to the
point of attachment of the filaments. It was assumed that a representa-
tion of the action of the tentacles would be obtained by squirting water
under pressure through the holes in the artificial lophophore. Unfortu-
nately, examination of the living filaments shows at once that this
assumption is wrong, and that the experiments consequently were
valueless. The gills of Brachiopods have, however, been investigated
more recently by Shipley, who described the gill-filaments of Argiope
as having cilia on three of their four sides, and figures these cilia as being
all similar (see 4, Plate 39, Fig. 13). Later, Shipley (5) states that im
Brachiopods “the cilia which clothe the tentacles (i.e. gill-filaments or
cirri) keep up a constant flow of water into the mantle cavity. This
stream not only serves to aerate the blood of the animals—a process
which probably takes place through the thin inner lining of the mantle
—but it also brings with it a number of diatoms and other minute
organisms which serve as food. These particles become entangled in the
tentacles, and are ultimately lodged in the groove at their base, and
passing along this by the action of the cilia they find their way into the
wide mouth, into which the groove deepens in the posterior median
line.” It will thus be seen that the manner in which the chief food-
current is produced and the differentiation of gill-cilia noted in the
following pages have not been described. Moreover, it will be shown
here that there exist in various parts of the body other ciliary mechanisms
than those on the gill, which play an important part in the process of
feeding.
CILIARY MECHANISMS PRODUCING THE MAIN FOOD AND
RESPIRATORY CURRENT IN BRACHIOPODS.
Brachiopods—like Amphioxus, some Molluscs, and other animals—
obtain their food by maintaiming a continuous current of water through
a cavity enclosed by portions of the body, and capturing the organisms
ON CILIARY MECHANISMS. 285
brought along with the current by means of a suitable organ, namely
the lophophore, placed between the ingoing and the outgoing currents.
The main food and respiratory stream in Crania enters the mantle
cavity at both sides and is expelled in the middle of the front of the shell
opposite the hinge (see Fig. 1). It will be remembered that the lopho-
phore in Brachiopods is distributed symmetrically on each side of the
antero-frontal axis of the shell. The effect of this disposition is—as will
be shown later—to divide the mantle cavity in a physiological sense*
ingoin
ee CETTenE
te {goin
curren
i" 1»
ey
current
Fic. 1.—View of Crania attached to a stone in the act of feeding. Drawn from the
living animal and chiefly from the right side (x 10). An ingoing current is drawn
into the lower portion of the mantle cavity on each side in the antero-lateral
region. The outgoing current leaves the region of the shell in the front middle
line. The double row of the protruded gill-filaments is well shown.
into two compartments, each containing a half of the lophophore on each
side of the mouth. Consequently two inhalent streams are necessary and
enter the mantle cavity, as shown in Figs. 1 and 2. The exhalent streams
are, however, combined in Crania, Lingula, and probably most recent
Brachiopods in the middle line in the front region of the shell.
These main food-currents in Brachiopods are produced chiefly by the
lashings of definite rows of cilia situated along the sides of the filaments
of the lophophore (see Figs. 3 and 7, pp. 287, 292). Groups of other
cilia, however, on other parts of the lophophore and on the mantle
* The mantle cavity is in many genera partially divided also morphologically by
septa, viz. Waldheimia, Stringocephalus. (See also p. 295.)
286 J. H. ORTON.
assist in producing these food-streams. The action of the mantle cilia
indicates fairly well the course of the food and respiratory streams
through the mantle cavity, and the directions in which the cilia on the
lower mantle lash are indicated by the arrows in Fig. 2. From the figure
it will be seen that the cilia lash from both lateral regions of the shell
towards the front middle region. Besides assisting in producing the main
current these cilia also reject from the mantle cavity the heavier un-
desirable particles brought into the shell in the main stream. On the
Fic. 2.—View of the ventral valve of Crania, showing the ciliary currents on the mantle
(x rather more than 3).
This view serves almost equally well for the ciliary currents on the dorsal
mantle.
The dotted arrows indicate the direction in which the mantle cilia lash, and
the large continuous arrows the regions where the greatest volume of the ingoing
current enters the mantle cavity.
mantle lining the upper valve the cilia lash on the whole in similar
directions to those on the lower one; there are, however, these differ-
ences, the cilia on either side of those in the front middle region lash more
and more away from the middle the nearer they are situated to the
anterior edge of the mantle. Thus two vortices tend to be formed
in the right and left upper portions of the mantle cavity. On
the dorsal mantle cilia also lash from between the anterior and
posterior occlusor muscles on each side towards the posterior sinus of
the mantle cavity which constitutes the space bounded by the posterior
ON CILIARY MECHANISMS. 287
occlusors and the “‘ hinge.” Into this sinus opens the anus. An outgoing
current from this part of the mantle cavity passes between the anterior
occlusors to join the main outgoing stream (see Fig. 2). Thus the currents
set up by the mantle cilia on each side of the mantle cavity divide into
two streams, the major one passing towards the middle of the cavity
and out at the front of the shell in the middle line, and a minor one pass-
ing between the occlusor muscles into the posterior sinus, from which
the outgoing stream passes between the anterior occlusors to join the
major outgoing stream. It will be shown later that the currents set up
by the mantle cilia are in the main coincident with those produced by
the current-producing cilia on the gill-filaments and certain cilia on the
lophophore.
C.
D. le. fe. B.
Se \
NMI dik cate el ar errr hUL Aen aH chro tT A Nh
Si WH D PHAN § SNORE ao Lider
Arts Pe
SNE TN
Fic. 3.—Lateral views of living gill-filaments of Crania (x about 56).
A. *View of portion of a filament of the ventral series (the letter is placed near
the distal end of the filament segment).
B. View of portion of a filament of the dorsal series (the letter is placed near the
proximal end of the filament segment).
C. Arrow indicating the direction in which the lateral cilia, l.c., lash.
le. Lateral cilia which produce the main current.
D. Arrow indicating the direction in which the frontal cilia, f.c., lash.
f.c. Frontal cilia which collect and transport food-particles.
CILIARY MECHANISMS ON THE GILL-FILAMENTS AND
LOPHOPHORE.
The examination of living gill-filaments of Crania and Terebratula
under a high power of a microscope revealed the presence of two sets
of cilat which correspond in function and position to those on the
filaments of Amphioxus, many Molluscs, and most Ascidians. These
sets of cilia are well shown in the transverse sections of the filaments
* This view would serve equally well for the tips of both kinds of filaments.
+ Blochmann (10) has already figured the differentiation of cilia on the filaments of
Crania, without, however, making any observations on their function.
288 J. H. ORTON.
shown in Fig. 7, p. 292,and in the lateral view of a living filament shown in
Fig. 3. From these figures it is seen that the cilia are differentiated
into three rows, one extending along that face of the filament which
faces the incoming current, and two extending either along the sides of
the filaments or along the edges of the filaments at the sides of the former
row. Those rows of cilia on the face of the filament facing the incoming
current may be called frontal cilia in comparison with the similar cilia
Fra. 4.—Diagram of the currents present in the mantle cavity of a Brachiopod as repre-
sented by Crania.
The diagram represents a section taken on one side of the median antero-
posterior axis through the shell and the whorls of the lophophore. One anterior
and one posterior occlusor muscle are shown.
The larger arrows indicate the course of the main current through the mantle
cavity. The large arrow whose head ends above the letter A indicates the course
of the ingoing current and the one beginning below B that of the outgoing current.
The three arrows between and to the right of A and B indicate the course of the
current through the gill-filaments on the lophophore. The dotted arrows on
either side of A indicate the region where the heavier food-particles fall out of
the main stream on to the mantle and are expelled by the mantle cilia as indicated
by the long dotted arrow placed parallel to the lower mantle. The direction
in which the cilia lash on the dorsal mantle is shown by the dotted arrow along-
side it. The small dotted arrows on the lophophore and gill-filaments show the
course of the food-collecting streams.
A. Inhalent chamber of one side.
B. Exhalent chamber of one side.
described in Molluscs and Amphioxus (see 1 and 2), while the rows of
cilia on the sides of the filaments may be similarly called lateral cilia.
Thus the faces of the filaments may be termed respectively frontal,
lateral, and ab-frontal, the latter being the face opposite the frontal.
The lateral cilia (well shown in Figs. 3 and 7 l.c.) are the chief pro-
ducers of the main food and respiratory current in Brachiopods. They
lash across the length of the filament, as shown in Fig. 3, from the lower
portion of the mantle cavity to the upper. The origin of the lophophore
ON CILIARY MECHANISMS. 289
from the body is such that the plane of the first and longest turn of the
lophophore on each side subtends the antero-lateral angle of the shell.
Y)) DY \)') ‘\)
af- - {2
=e
-— Fe
“td 1 Tad LA
Fie. 5.—View of a portion of the lophophore, including the buccal groove and the
base of five gill-filaments of Crania. Three of the filaments are ventral and two
dorsal ones.
(For the sake of convenience the lophophore is magnified less than the gill-
filaments. Drawn from the living object.)
The dotted arrows indicate the direction in which the cilia on the body of the
lophophore lash, the arrows on the filaments the direction in which the food-
collecting, the frontal cilia lash, and the thin-lined arrows below the buccal lip.
the direction in which the cilia lash in the buccal groove.
A. Ridge on the lophophore away from which the cilia on both sides lash.
B. Arrows indicating the direction in which the lateral, i.e. current-producing.
cilia, lash.
B.l. Buccal lip overlying buccal groove.
B.gr. Buccal groove along which are carried the particles from the lophophore.
ie: Lateral cilia.
face Frontal cilia.
v.f. Filament of ventral series.
a.f. (d.f.) | Filament of dorsal series.
Consequently the main current is drawn into the shell at the antero-
lateral angles, since the lateral cilia lash on the whole in a direction at.
right angles to the plane of the lophophore.
290 J. H. ORTON.
When Crania is feeding the gill-filaments are extended in the plane
of the lophophore and extruded beyond the opening of the shell, as
shown in Fig. 1; they are also usually kept close to the upper valve.
This disposition of the filaments permits a selection of the finer food-
particles, for the heavier particles in the ingoing current drop out of the
stream at the entrance to the mantle cavity and are rejected by the cilia
on the lower mantle as shown in Fig. 2. The main current, however,
passes between the filaments on the first turn of the lophophore and
onwards through the filaments of the succeeding turns of the spiral lopho-
phore—which are superposed one above the other (see Fig. 4, p. 288)—
to be passed out of the mantle cavity finally in the anterior middle
portion as has been seen. Thus in traversing the mantle cavity the
food-stream passes successively through a number of sieves which are
formed by the tiers of filaments on the lophophoral spiral. This arrange-
ment is probably very effective in sieving off the food-particles, although
at first sight the somewhat straggling appearance of the filaments does
not give this impression. The efficiency of the sieving action of the
filaments, moreover, is further enhanced by the fact that the filaments
are arranged in two distinct alternating rows at the edge of the lopho-
phore (see Fig. 5, p. 289), one row being slightly behind the other, as
shown in Fig. 7, which is a transverse section of a group of filaments
taken near their origin from the lophophore.* As a result of this dis-
position the lateral rows of cilia near the base of the upper filaments lash
directly on to the frontal face of the lower ones, that is, directly on to the
frontal cilia, which are the principal agents in catching food-particles.
An additional minor factor in producing the main food and respira-
tory stream are the cilia on the body of the lophophore, which have also
been figured by Blochmann. These cilia also assist partially in collecting
food-particles and their action may best be gathered from Fig. 5, p. 289
and a diagram of a transverse section of the lophophore (see Fig. 6, p. 291).
The cilia on the frontal surface of the lophophore are differentiated into
two sets separated by a ridge running along the middle of the spiral,
but slightly towards the outer, Le. filamentar side. The cilia on the
filamentar side of this ridge are very powerful and lash towards the
filaments, those on the other side lash away from the ridge in a direction
mainly transverse to the length of the lophophore, but also slighily
oblique, towards the proximal end, as shown in Fig. 5, p. 289. The
* The arrangement of the filaments on the lophophore is probably universal in
Brachiopods, as it has been observed by Van Bemmelen in Terebratula (6) and Bloch-
mann (10) in Crania, Discina, and Lingula. Oehlert (14) also makes the general statement
that they are arranged in two rows in Brachiopods.
ON CILIARY MECHANISMS. 291
cilia on the ab-frontal face are similar to those on the frontal face (see
Fig. 6, below). Thus there are two broad zones of cilia on the filamentar
side of both faces of the lophophore lashing towards the filaments and so
assisting in producing the food-current, and two zones lashing towards
the mner edge of the lophophore, along which particles are carried
around the inside of the spiral to its base. At the bases of the two
arms of the lophophore the particles carried along the inner edge of the
lophophore are passed on to the lower mantle, whence they are expelled
from the mantle cavity.
SSS SS SEE
= Sorensen ENT TP 3
ease gales
eee RIT eS eas Se.
wee aE SSS SSS DE Oe crn x
Fic. 6.—Semi-diagrammatic transverse section of the lophophore of Crania to show
the difference in the action of the cilia on its various parts as indicated by the
adjoining arrows.
A. Arrow indicating the direction in which the current-producing cilia lash
on the portion of the gill-filament E.
B. Arrow indicating the direction in which the frontal cilia on the gill-
filament lash.
B.gr. Buccal groove along which food is carried to the mouth.
B.1. — Buecal lip.
C. Inner edge of lophophore along which particles are carried to its base.
D: Region from either side of which the cilia lash in opposite directions,
resembling a watershed.
E. Base of a gill-filament arising from the lophophore.
m. Mucus globules.
It will now be seen that there are three factors concerned in the pro-
duction of the main food and respiratory stream in Crania—and probably
in most, if not all, Brachiopods—namely, the rows of lateral cilia on the
gill-filaments, which are the most important factor, the cilia on the
filamentar sides of the body of the lophophore, and the cilia on the mantle
lobes.
Food-collection in Brachiopods is effected chiefly by the frontal cilia
on the gill-filaments, and partially by the cilia on the frontal face of the
outer side of the body of the lophophore. The cilia on the frontal face
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914. ah
292 J. H. ORTON.
of the filaments collect food-particles and lash them towards the base
of the filaments into the food groove (see Fig. 5, p. 289). In the same
way the frontal cilia on that part of the lophophore adjacent to the
food groove entrap food-particles and lash them along the face of the
lophophore either on to the base of the filaments or towards the powerful
cilia at the edge of the buccal lip (see Fig. 5). These cilia quickly push
the particles under the lip into the food groove. The food-particles, on
entering the food groove, are then carried along towards the mouth, as
has been stated by Shipley, being rapidly transported thence by very
Fic. 7.—View of transverse section of five ventral and four dorsal gill-filaments of Crania.
taken near the lophophore, showing the alternation of the filaments in these two.
series. :
(The outlines of the sections were drawn with the camera lucida, and the.
remainder filled in slightly diagrammatically (x about 192.)
The arrows indicate the directions in which the lateral cilia lash, and it will be-
seen that those of the smaller ventral filaments lash directly on to the frontal,
surface of the larger dorsal filaments.
lic. Lateral cilia which lash across the length of the filament, as indicated by
the arrows, to produce the main current.
f.c. Frontal cilia, which lash along the length of the filament and collect and
transport food particles.
m. Globules of mucus seen in all the sections on various parts of the frontal
and lateral sides of the filamentar epithelium.
g.s. The gill-filament supports.
sirong cilia. In the process of food-collection the secretion and trans-
portation of mucus plays an important part, for the mucus when spread
out in thin layers forms an efficient method of capturing and retaining
captured food-particles, and is also easily transported in this form by
cilia. Mucus serving this purpose is secreted by the frontal epithelium
on the gill-filaments and especially by that of the dorsal filaments, where
the secreting cells occur chiefly in the trough of the filamentar groove.
(see Fig. 7, above, and also Van Bemmelen, 6, Taf. 8, Fig. 6, in a section
of a gill-filament of Rhynchonella psittacea). Blochmann (10) has.
described ageregations of mucus cells between the bases of the filaments,
that is, in the buccal groove, and also others scattered over the epithelium
ON CILIARY MECHANISMS. 293
of the lophophore. ‘The secretions of these latter cells assist in a similar
way to that from the filaments in the capture and transportation of
food-particles.
THE CILIATION OF THE GILL-FILAMENTS OF BRACHIOPODS:
The cilia on the gill-filaments of Brachiopods are arranged in three
rows along the length of the filament, as has already been described.
There are, however, as Oehlert has observed, two kinds of filaments, a
larger and a smaller, as is shown in Fig. 7, p. 292. The smaller ones
constitute the ventral series (that is, the series facing the incoming
current) on the lophophore and alternate with the larger ones in the
dorsal series (see Fig. 5, p. 289). These two kinds also differ in the arrange-
ment of the rows of cilia. On the smaller ones the lateral cilia are situated
on the sides of the filaments and near the ab-frontal face, while in the
larger filaments they occur similarly on the sides, but near the frontal
face, except towards the tips of the filaments, where these current-produc-
ing cilia graduate towards the ab-frontal face (see Fig. 3, p. 287). The
disposition of the rows of cilia is well shown in Fig. 7, p. 292, which
represents transverse sections of the two kinds of filaments taken near
their origin from the lophophore. In the smaller sections the filaments
are shown to be nearly cylindrical and the greater part of the convex
face occupied by the frontal, that 1s, food-collecting cilia. The larger
cilia on the sides of the filaments are the lateral or current-producing
cilia. Both these rows of cilia arise from columnar cells which have long
elliptical nuclei. On the contrary the non-ciliated ab-frontal epithelium
is composed of squarish to flattened cells with more or less spherical
nuclei, and indeed it would appear that the character of an epithelium
on any gill-filament forms a very good guide as to whether or not that
epithelium is ciliated; if the cells in a portion of an epithelium are
columnar and the nuclei elongated they probably bear cilia, whereas
if the cells are squarish to squamous they are probably not ciliated.
Such an interpretation of portions of an epithelium on gill-filaments
may be useful in cases where it is difficult to obtain well-preserved material,
for as is well known it is difficult to determine what part of an epithelium
is ciliated unless such material can be obtained. One good illustration
of this fact is afforded by the well-drawn figure of a transverse section of
a gill-filament of Rhynchonella given by Van Bemmelen (6, Plate 8,
Fig. 6). In this figure no cilia are shown at all, although the characters
of the epithelium are seen to be almost identical with that of the smaller
sections in Fig. 7, p. 292. A somewhat diagrammatic transverse section
294 J. H. ORTON.
of a filament of Argiope is figured by Shipley (4), who depicts uniform
cilia on three of the four sides of the filament. Examination of the liv-
ing filaments* and sections of specially preserved material, however, would
doubtless show that a differentiation of cilia occurs here as on the filaments
of Crania, Rhynchonella, Terebratula, and other forms. Blochmann,
however, has given beautiful figures of transverse sections of the gill-
filaments of Crania, in which the differentiation of the lateral and frontal
cilia is very well shown in a section of a filament of the dorsal series, but
less well in that of a ventral filament. This writer also gives rougher
figures of Discina and Lingula, without, however, figuring the cilia, but he
remarks that the filaments of these two forms are essentially similar in
their characters to those of Crania. Hence there can be no doubt that
the gill-filaments of all Brachiopods have cilia disposed and differentiated
in the same way as in Crania.
SUMMARY OF CURRENT-PRODUCING MECHANISMS AND THE
MODE OF FEEDING IN BRACHIOPODS.
The main current through the mantle cavity in Brachiopods is pro-
duced chiefly by the lateral cilia on the gill-filaments and partially by
cilia on the mantle and on the body of the lophophore. The disposition
of the lophophore and the filaments on the lophophore is such that two
ingoing currents of water are established at the sides of the mantle
cavity. On each side the current passes between the filaments of the
first turn of the lophophore and outwards through the filaments of
the second and succeeding turns of the lophophoral spiral into the
median dorsal region of the mantle cavity. At this point the currents
from each side meet and pass out of the mantle cavity a the middle of
the anterior region of the shell.
The food-particles brought into the mantle cavity in the main stream
are caught by the frontal cilia on the gill-filaments, and by those on the
outer frontal portion of the lophophore, and transported by these cilia
into the buccal groove. In the buccal groove the food-particles are lashed
rapidly along to the mouth by the strong cilia on the buccal lip and fused
bases of the filaments. It seems probable that the food-stream in Brachio-
pods is effectively sieved by the gill-filaments, since besides collecting
food-particles the ventral ones lash directly on to the food-collecting
face of the lower filaments which alternate with them: moreover, part
of the food-stream is repeatedly sieved in most forms by the filaments
on the superposed whorls of the lophophore.
* Subsequent examination of living Argiope from Naples has shown this statement
to be correct.
ON CILIARY MECHANISMS. 295
In Crania a selection of the finer food-particles is effected in the follow-
ing manner: the ingoing currents are drawn into the dorsal portion of
the mantle cavity, hence when the dorsal valve is uppermost—as fre-
quently happens—the heavier particles drop on to the ventral mantle,
whose cilia discharges them either outside the mantle cavity or carries
them to the edge of the mantle, whence they are shot away by the animal
suddenly clapping together the valves of the shell. Modifications in the
manner of rejecting unsuitable food-particles probably occur in other
Brachiopods in much the same way as has been observed in Lamelli-
branchs (1, pp. 457 to 463).
AN EXPLANATION OF SOME MORPHOLOGICAL CHARACTERS
IN FOSSIL AND RECENT BRACHIOPODS.
In the foregoing description it has been shown that in certain Brachio-
pods, as, for example, Crania, there is a physiological subdivision of the
main part of the mantle cavity into right and left portions, and it would
seem highly probable that in all Brachiopods there is a similar sub-
division of the mantle spaces, since the disposition of the lophophore is
fundamentally similar in them all. Unfortunately few observations
have been made on the nutritive currents of Brachiopods, but those of
Morse on Lingula (7, p. 157) are of interest. Morse found that Lingula
lives embedded in sand, and that ‘‘ while partially buried in the sand
the anterior border of the pallial membranes contract in such a way as
to leave three large oval openings, one in the centre and one on each side.
The bristles, which are quite long in this region of the animal, arrange
themselves in such a way as to continue these openings into funnels and
entangle the mucus which escapes from the animal ; these funnels have
firm walls. A continual current is seen passing down the side funnels and
escaping by the central one.”’* These observations have been confirmed
by Francois (8) in so far as he figures the trilobed apertures of the burrows
of this animal (see also Camb. Nat. Hist., Vol. 3, Fig. 321). Thus there
can be little doubt that the mantle cavity is subdivided in Lingula in
the same way as in Crania.
In these respects it is a highly interesting fact that many Brachiopods
both recent and fossil have a trilobed shell whose apertures correspond
to the inlets for ingoing currents and the outlet for the outgoing current
(see Fig. 8 C, p. 296), but it is probably still more interesting and remark-
able that in some forms, as in Conchidium Knighti, the mantle cavity is
* The italics are mine.
296 J. H. ORTON.
practically subdivided into right and left portions by a median septum,
and that in others, as in Terebratula janitor, the shell is actually divided
into two wings (see Fig. 8 A and B, below). Inall Brachiopods there would
thus appear to be little doubt of the physiological independence of the right
and left halves of the mantle cavity. Hence variations in the direction
of formation of antero-posterior median septa, as shown in Stringo-
cephalus, Conchidium, and many other genera, of trilobation of the shell,
as shown in many Rhynchonellide, and bilobation of the shell, as shown
in Orthis biloba, Terebratula diphya, and other forms, do not interfere
with the functions of the two portions of the lophophore, and it is con-
Fic. 8.—Views of types of Brachiopod shells showing morphological division of the
mantle cavity into right and left portions, and trilobation of the shell.
A. Shell of Terebratula (Pygope) janitor (after Oehlert) in which the mantle
cavity is almost entirely divided into two separate compartments. —
B. View of interior of shell of Conchidium Knighti (after Davidson) showing
internal partial subdivision of the mantle cavity by the septa which are
shaded.
C. Frontal view of the shell of Rhynchonella cynocephala (after Oehlert), showing
the anterior median portion of the shell produced into a sort of siphon
in the region in which in other Brachiopods (for example, Crania and
Lingula) is expelled the outgoing current.
ceivable that these variations may be advantageous to certain forms
under certain conditions. f
The disposition of the lophophore in the Spiriferide indicates that the
main ingoing current entered the mantle cavity in the front middle
portion and was expelled in two outgoing currents at the postero-lateral
angles of the shell, a condition exactly the reverse of that obtaining in
Crania, where the ingoing current is twofold and the outgomg current
single. Thus the production of the shell—frequently occurring in this
group—into postero-lateral angles, somewhat like those occurring in
modern Pectens, may have served as a sort of siphon for carrying away
the exhalent streams.
ON CILIARY MECHANISMS. 297
COMPARISON OF THE CILIARY MECHANISMS ON THE GILLS
OF GASTROPODS, LAMELLIBRANCHS, AMPHIOXUS, AND
BRACHIOPODS.
The ciliary mechanisms concerned in producing the main food and
respiratory current in Gastropods, Lamellibranchs, Amphioxus, Asci-
dians, and Brachiopods have now been shown to be essentially similar
in all these groups (see preceding pages and Orton, 1* and 2, and Herd-
man, 9). The main current is produced in all groups alike chiefly or
entirely by the rows of cilia, the lateral cilia situated at the sides of the
gill-filaments (see Fig. 9, p. 299): for the term “ gill-filament ” may be
used as well for the gill-bars of Amphioxus or Ascidians and the lopho-
phoral cirri of Brachiopods as for the elements of the ctenidium of
Gastropods and Lamellibranchs.. These rows of lateral cilia lash across
the length of the gill-filaments in all cases and set up a current towards
and at right angles to the gill. The current thus produced brings into
the mantle cavity—or the branchial sac in the case of the Protochordata—
food-particles, which serve for the nourishment of the animal, and also
brings the means for oxydation of the tissues, while the expulsion of the
current from within the cavities of the animals serves to carry away the
waste products resulting from the various activities of the organisms.
The food-particles carried in the main current into the spaces of all
these animals are arrested on the gill which is necessarily interposed
between the ingoing and outgoing currents, and acts like a sieve. The
actual collection of food-particles varies somewhat in the different
groups. Food-collection is effected chiefly, however, in all the groups
by means of rows of cilia on those faces of the filaments facing the on-
coming current, that is, on the frontal faces. In some Lamellibranchs—
which are curiously distributed throughout the group, as Nucula, Sole-
nomya, Anomia, Mytilus, Cardium, Ostrea, Tapes—there are additional
food-collecting cilia on the latero-frontal edges of the gill-filaments.
These latero-frontal cilia are true straining cilia, and lash across the
length of the filament at right angles to the oncoming current and away
from the inter-filamentar spaces. In this way they pass particles on to
the frontal cilia, and indeed are so numerous in these animals as to give
* In a paper written in 1910 Bourne (11) states of the lateral cilia of the Gastropod
Incisura (Scissurella) lytteltonensis that he does not think “‘ that their function is to hold
the filaments together, but simply to create currents over the surfaces of the filaments.”
I hasten to give this reference because I only became aware of it after my paper on the
ciliary mechanisms in Gastropods was published. From the researches described in that
paper it is now seen that there is an element of truth in the suggestion made by Bourne.
298 J. H. ORTON.
the appearance of flexible combs working along the sides of the filaments.
The frontal cilia in all forms lash the food-particles into a food-groove,
whence the particles are carried to the mouth or cesophagus. It is an
interesting fact that the frontal cilia are in all cases short, as compared
with the length of the lateral or the latero-frontal cilia, and it is probable
that short cilia would be much more effective than long ones in trans-
porting food-particles and masses of particles embedded in mucus, and
would, moreover, be more easily controlled and less hable to become
intermixed and so interfere with their fellows.
Food-collection is also assisted in some Gastropods as in Crepidula,
and some Lamellibranchs as in Nucula, by rows of cilia on the ab-frontal
faces of the filaments, but probably the function of these rows of cilia in
assisting in producing the main current is more important than that of
food-collecting. In Amphioxus and Ascidians cilia on the epithelium of
the atrial cavity help in a small way in producing the main stream.
The distribution of the cilia on the gill-filaments of Gastropods,
Lamellibranchs, Amphioxus, and Brachiopods is shown in _ the
transverse sections depicted in Fig. 9, p. 299. From these figures the
essential similarity of all the filaments is at once apparent. The position
of the lateral cilia is, however, somewhat different in the types of filament
represented by those of Crepidula and Crania. In those filaments the
lateral cilia occupy a position much nearer the ab-frontal surface of the
filament. It is probably significant that in both Crepidula and Crania
the gill-filaments are free and without any extensive interlocking arrange-
ments such as exist in Lamellibranchs, or such a consolidation as occurs
in Amphioxus and Ascidians. It is very probable therefore that the
receding of the lateral cilia from the frontal surface in these forms is an
effort to compensate for the lack of compactness in the gill, by exposing
a larger food-collecting, that is, frontal surface.
A glance again at Fig. 9 shows that in all these filaments internal sup-
ports (g.s.) are developed similarly, but with some differences in order to
maintain the gills sufficiently rigid in the form of either an open basket-
work or grid-iron sieve.
In an earlier paper (2) it has been suggested that the function of the
gill in Crepidula, most Lamellibranchs and Amphioxus is merely that of
a water-pump and a food-sieve, and that the respiratory function is not
performed to any appreciable extent on the gill in these forms. In
Brachiopods, Shipley (4, p. 501) has arrived at the same conclusion with
regard to the function of the lophophore, of which he states: “I have
been unable to detect any blood corpuscles in the tentacles, and I believe
Gastropoda Lamellibranchia
Type A Type B
00% i a
: EV Gl OTR
Protochordata Brachiopoda
Fia. 9.—Transverse sections of the gill-filaments of members of Gastropods, Lamelli-
branchs, Protochordata, and Brachiopods, illustrating the essential similarity of
the ciliation of the filaments in all these groups. (Variously magnified.)
ie: Lateral cilia which produce the main food and respiratory current in all
the groups.
f.c. Frontal cilia which are the main food-collecting cilia in all the groups.
l.f.c. Latero-frontal cilia, which are special food-catching cilia present only in
some Lamellibranchs, as Nucula, Anomia, Mytilus, Cardium, and
others; they lash in the direction shown by the adjoining arrows.
ab.f.c. Ab-frontal cilia present and well developed in Gastropods and some
Lamellibranchs, but less well developed in Amphioxus and Ascidians ;
absent in Brachiopods. These cilia assist both in food-collection and
in producing the main current.
g.S. Internal supports for the gill-filaments and present in all the groups, but
additional support by calcareous spicules is given in some Brachio-
pods, as in Terebrutula vitrea, shown in the Brachiopod section B.
In the above types of gill-filaments Gastropods are represented by a transverse
section of a filament of Crepidula fornicata ; Lamellibranchs by two sections repre-
senting the two types of ciliation in this group. Type A is of Glycimeris glycimeris,
and would serve equally well for Pecten, Arca, and others. Type B is of Mytilus
edulis, and represents Nucula, Solenomya, Anomia. Cardium, Ostrea, Anodon,
and many others. Protochordata are represented by a section of a secondary gill-
filament of Amphiorus lanceolatus, but sections of Ascidian and Enteropneustan
(as represented by Ptychodera) gill-filaments are essentially similar to that of
Amphioxus in their ciliation.
The two kinds of filaments present in Brachiopods are represented by the
Brachiopod sections A and B. The section A is of a ventral filament of Crania
anomala, and B is of a dorsal filament of T'erebratula vitrea. ‘The latter section is
slightly idealized in that the supporting spicules present within the chitinovs gill-
support are represented in the drawing although dissolved out of the actual section
by the fixative. |
300 J. H. ORTON.
the sole function of the lophophore is to set up a stream by means of its
cilia, and so to bring diatoms and other articles of food to the mouth,
and that it has no respiratory function whatever. Indeed, it is difficult
to imagine how an interchange of gas could take place through the thick,
dense layer of supporting substance.”
There would appear to be little doubt that Shipley is correct, hence in
practically all the members of the above-mentioned groups the gill
probably functions merely as a water-pump and a food-sieve. In Crepi-
dula, most Lamellibranchs and Brachiopods respiration doubtless occurs
mainly in the mantle; while in Amphioxus a gaseous exchange
is probably effected chiefly in the coelomic spaces adjacent to the atrium.
In Ascidians respiration is doubtless effected in the branchial sac.
In all these gills there can be no doubt that mucus formation plays a
very important part in the process of food-collection. It has been shown
in an earlier paper (2) that in Amphioxus and Ascidians the mucus
formed in the endostylar groove of these animals is thrown on to and
transported along the gill-filaments in thin sheets to serve for entrapping
food-particles. In Lamellibranchs and Crepidula it has been suggested
that the corresponding mucus formation takes place in the frontal
epithelium of the gill-filaments, and indeed swollen cells, which are almost
certainly mucus cells, have already been figured in the epithelium of the
filaments of Mytilus (see I, Fig. 17, pass¢m). Similar globules occur also in
the filaments of Glycimeris, Crania (see Fig. 9, p. 299), Terebratula and
Rhynchonella (see 6). It is hoped to make this important problem the
subject of a special investigation.
The writer’s work, however, on the endostyle of Amphioxus suggested
the probable function of a previously enigmatical glandular organ
situated along the base of the gill-filaments of Crepidula. An examina-
tion of the living animal confirmed the suggestion that this organ is
indeed an endostyle, as may be gathered from the description of it in the
section on p. 303.
It is an interesting fact that the spines (clavulee) composing the
fascioles of the heart-urchins, Echinocardium and Spatangus, have been
found to have the cilia disposed in definite rows along their sides in a
manner very similar to that in which the lateral cilia are distributed on
the gill-filaments of all the above-mentioned groups. These rows of cilia
on the spines do, as a matter of fact, very closely resemble the lateral
cilia of gill-filaments in that they lash in a definite direction and with the
same wave-like motion characteristic of those current-producing cilia ;
they are also situated on opposite sides of the spines, and are indeed
ON CILIARY MECHANISMS. 301
current-producing cilia analogous to those of Gastropods, Lamelli-
branchs, Ascidians, Amphioxus, and Brachiopods.
The function of these spines is being investigated further, and figures
will be given to show their resemblance to gill-filaments. MacBride, how-
ever, is doubtless correct in stating (Camb. Nat. Hist., Vol. I, p. 550) that :
** Between the two posterior petals (in Echinocardium cordatum) there is a
hoop-shaped band of very small black spines. These spines are ciliated, and
draw a current of fresh sea-water over the respiratory tube-feet. Beneath
the periproct there is a similar band called the ‘ subyanal fasciole’ ; this
probably produces a current of water which sweeps away the material
ejected from the anus.”
THE CILIARY MECHANISMS ON THE GILLS OF CRYPTO-
CEPHALOUS POLYCHATES AND ON THE LOPHOPHORE
OF PHORONIS.
An examination has also been made of the cephalic gills of various
Cryptocephalous Polychetes. It has been found that these gills are
used for the purpose of feeding, and that the ciliary mechanisms con-
cerned in the feeding process in—for example—Spirorbis, Pomatoceros,
Hydroides, Branchiomma, Sabella, and Filograna are identical with
those on the gills of Lamellibranchs, some Gastropods, Amphioxus and
Brachiopods, that is to say, there are well-differentiated current-pro-
ducing lateral cilia and food-collecting and food-transporting frontal
cilia on the pimnules of the tentacles. Food is very rapidly collected in
these Polychetes and transported along the pinnules to the axes of the
tentacles and thence to the mouth. Further particulars and figures with
regard to these animals will, however, be given later.
The lophophoral cirri of Phoronis have also been investigated, but up
to the present it has only been possible to examine the living animal
cursorily. Nevertheless this short examination revealed the facts that
in this animal also the cirri—or gill-filaments—are differentiated into
lateral and frontal rows, and that a good current of water is drawn
towards the mouth within the space enclosed by the lophophoral cirri.
The functions of the lateral and frontal cilia in Phoronis, however, do
not appear to be identical with those of the similar cilia in Brachiopods
and the other groups mentioned above, but a more complete examination
of the living animal will be made later with a view to investigating fully
the ciliary mechanisms concerned in process of feeding in this animal.
J. H. ORTON.
Fic. 10.—View of the mantle cavity and gill of Crepidula, showing the endostyle at the
base of the gill. (The animal has been taken out of its shell and the mantle turned
over to the left.)
The dotted arrows on the endostyle, En, indicate the directions in which
mucus is lashed from the endostyle on to the base of the gill-filaments.
EN.
f.ch.
v.m,
Pate
Endostyle from which mucus and food-particles are lashed on to the
gill-filaments.
Ciliated groove along the left side of the endostyle carrying mucus for-
wards to the food-pouch, as indicated by the complete arrows.
Food-pouch in which the heavier food-particles become lodged.
Food-channel on the right side of the body extending along the visceral
mass and the “‘ neck”’ region of the animal towards the mouth. In
this channel is collected the main mass of collected food-particles
which are carried in the direction indicated by the arrows.
Foot.
Visceral mass.
Gill-filaments.
ON CILIARY MECHANISMS. 303
THE ENDOSTYLE OF CREPIDULA AND CALYPTRAA.
At the base of the gill-filaments of Crepidula and Calyptreea there is
a group—or rather there are two groups—of large glandular ciliated cells
which secrete a mucoid substance (see Figs. 10 and 12, p.304). Examination
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Fic. 11.—View of the endostyle and the bases of four gill-filaments of Crepidula fornicata
highly magnified. (Drawn from the living object.)
The dotted arrows on the endostyle, EN, and the complete ones on the bases
of the gill-filaments indicate the direction in which mucus is passed from the
endostyle on to the bases of the gills. The dotted arrows on the mantle on the
floor of the inhalent chamber. m, show the direction in which the cilia in this
region lash. Similarly the forward stream in the ciliated groove, c.gr., on the left
of the endostyle is indicated by the overlying dotted arrows.
EN. The endostyle consisting of two rows of gland cells between and to the left
of which are rows of specially differentiated ciliated cells.
e.gr. Ciliated groove on the left of the endostyle.
g.f. The bases of the gill-filaments.
f.c Frontal cilia of gill-filaments.
m. The mantle covering the floor of the inhalent chamber.
of the living gill and the surrounding parts shows that the cilia of these
glandular cells lash the secreted mucus on to the bases of the gill-filaments,
whence it is passed along the face of the gill to be used for the purpose of
entrapping food-particles (see Figs. 10 and 11, above), as has already been
304 J. H. ORTON.
described in this Journal (1, pp. 448, 455). I thought formerly that this
mucus was secreted by the epithelium of the gill-filaments (loc.cit.), but there
is no doubt now that the greater part is secreted by the glandular cells at
the base of the filaments, although it is not unlikely that a certain amount
I .ch.
Fic. 12.+—Transverse section of the endostyle of Crepidula (x about 105).
A. Arrow indicating the direction in which the mucus from the endostyle is
passed on to the base of the gill-filaments.
EN. Two rows of groups of gland cells in the endostyle, between and to the left
of which is a group of ciliated cells with apical nuclei.
gf. Gill-filament.
f.c. Frontal epithelium and frontal cilia on gill-filament.
Le: Lateral cilia on gill-filament.
g.s. Gill-filament support.
c.gr. Ciliated groove to the left side of the endostyle.
m. Epithelium of mantle the cilia on which lash towards the main food-
channel on the right side of the body as indicated by the arrow
placed alongside.
I.ch. Inhalent chamber.
E.ch. Enhalent chamber into which the main current is passed from the
inhalent chamber as indicated by the arrow crossing the gill-
filament.
of mucus may be secreted by the epithelium of the gill-filaments. These
groups of grandular cells may be properly termed an endostyle, since they
* I am indebted to Mrs. Orton for the drawing for this figure as well as those for
figures 1, 2, and 8, and also for assistance with all the other drawings except that for
Fig. 3; and also to Mr. E. Ford for kindly lettering Figs. 3, 4, 6, 7, 9 to 12.
ON CILIARY MECHANISMS, 305
have the same function as the similar groups of glandular cells in a similar
position in Amphioxus and Ascidians. The cilia on the endostyle of
Crepidula and Calyptreea lash mucus and food-particles on to the gill as
has already been stated, but there is also a ciliated groove on the left
side of the endostyle which lashes some mucus and captured food-particles
forwards (see Fig. 10). This forward stream of mucus contributes largely
to the forward stream in the mantle cavity which has already been de-
scribed (1, p. 448), and whose function is chiefly that of entrapping the
coarser food-particles at the entrance to the inhalent chamber. By means
of the mucus which is thus carried along this ciliated channel a large
proportion of the larger and often innutritious particles become lodged
in the food-pouch in the middle of the front portion of the mantle, and are
either rejected or eaten by the animal, as has already been observed
(1, p. 448). In this way and to this extent these animals are able to select
their food.
The character of the endostyle of Crepidula may be gathered from the
views shown in Figs. 10 and 11, and the transverse section shown in Fig. 12.
From the transverse section it is seen that there are two rows of long
glandular cells with basal nuclei, and between and to the left of
these rows is a line of curious ciliated cells with an apical or distal
nucleus. On either side of the endostyle, the epithelium consists
of columnar ciliated cells, which become more cubical as_ they
recede from the endostyle. The epithelium on the right side
(seen on the left in the section) passes into that of the floor of the
mantle cavity. In the latter region the cilia lash away from the
endostyle towards the right side of the mantle cavity, and while thus
assisting in producing the main current, at the same time help in collect-
ing food-particles into the food-groove on the right side of the floor of
the mantle cavity (see Fig. 10, p. 302). The characters of the endostyle
and the ciliation of the mantle are the same in Calyptreea as in Crepidula.
In Capulus these characters are also the same in the living animal, but
sections of the endostyle have not yet been examined.
The remarkable likeness of the endostyle of Crepidula and its allies to
that of Amphioxus and Ascidians becomes still more evident when it is
compared—as it should be—to a half, the right half, of that of Am-
phioxus and Ascidians: for it is to be remembered that there is only
one half of a ctenidium and only one series of filaments present in Crepi-
dula, whereas both a right and left series of “ filaments ” exist in Am-
phioxus and Ascidians. When, therefore, the endostyle of Crepidula is
compared with the right half of that of Amphioxus and Ascidians it will
306 J. H. ORTON.
be seen that in both there are two rows of similar long glandular cells
with basal nuclei, separated by a row of ciliated cells with apical nuclei.
The function of the intermediate row of ciliated cells in Amphioxus has
been shown to be that of passing on to the gill the mucus formed by the
gland cells (see 2, Fig. 3, and p. 25), and the function of the corre-
sponding cells in the endostyle of Crepidula is the same.
It has now been shown (1) that the endostyles in Amphioxus,
Ascidians, and Crepidula, and its allies* show a remarkable resem-
blance, and also that the ciliation and internal supports of the
gill-fillaments in Gastropods, Lamellibranchs, Amphioxus, Ascidians,
and Brachiopods are essentially the same. Consequently it is clear
that the homological} value of any of those characters cannot
be great since they are present in widely divergent groups, and indeed
would appear to be merely similar adaptations to a similar method
of feeding. Therefore it follows that organs present in different animals,
but having the same functions, are never necessarily homologous, since
practically identical organs are here shown to occur with the same
function in groups which are undoubtedly only remotely related.
These groups are indeed so remotely related that the characters of
the ciliation and internal supports of the gill-filaments, on the one
hand, and the endostyle in Crepidula and in the above-mentioned
Protochordates,f on the other hand, must have arisen independently
in each case to meet similar requirements. Such plasticity in
organisms is indeed remarkable, and its demonstration necessarily
increases the difficulties in the already difficult problem of determining
what organs in different animals really are genetically related. For
instance, the presence of an endostyle in Crepidula confounds all the
arguments that we can advance at present in support of the theory
that the parabranchial ridges of the Enteroprensta are homologous with
the endostyle of Amphioxus (see Willey, 15). These organs may possibly
be homologous, but we have no means of determining with any certainty
that they really are; and a similar uncertainty must exist in other
similar cases.
* It is not improbable that an endostyle may be present also in many other aquatic
Gastropods.
+ The term Homology is used with the meaning Lankester gives to the term Homo-
geny (see 16).
+ It is not contended that the endostyle has arisen independently in Amphioxus and
Ascidians, for the well-known reason that development in the latter group indicates a not
extremely remote relationship of that group with Amphioxus.
ON CILIARY MECHANISMS. 307
COMPARISON OF THE ADAPTATIONS IN BRACHIOPODS AND
LAMELLIBRANCHS TO THE PROCESS OF FEEDING.
The general resemblance of the shell and mantle lobe in Brachiopods
and Lamellibranchs, as well as the general similarity of their feeding
organs, renders a comparison of the adaptations in these groups to the
process of feeding a matter of some interest. It has been shown in an
earlier work (1, p. 463) that it is highly probable that Lamellibranchs
have evolved in the direction of perfecting the gill as a feeding organ.
In all Brachiopods, so far as is at present known, the feeding organ, the
lophophore with its gill-filaments, is in a condition comparable with that
of the lower Lamellibranchs, namely, the Protobranchia and the more
lowly Filibranchia. No process of fusion of the filaments appears to have
taken place in any Brachiopod similar to that generally recognised as
having occurred in Lamellibranchs. Since in the latter group this process
of fusion appears to have been one of the main factors governing the
evolution of that group, the absence of such a process of fusion in Brachio-
pods may very probably be one of the factors which has resulted in the
present decadent condition of that group. Along with the absence of
fusion of the gill-filaments in Brachiopods are correlated the absence of
fusion of the mantle lobes and the formation of siphons, both of which
characters are in many cases of prime importance in the feeding process.
Doubtless other disadvantages under which Brachiopods suffer—in
comparison with Lamellibranchs in general—are the absence of a loco-
motory organ in the adult stage represented by the foot in Lamelli-
branchs, and the sedentary life necessitated in Brachiopods by their
structure. These two factors debar Brachiopods from the liberty
Lamellibranchs mostly have of moving about, and so being able to
place themselves to some extent in a suitable environment. Thus,
therefore, probably the sum of these disadvantages may account in some
measure for the decadence of the group of Brachiopods, as compared
with the flourishing condition of Lamellibranchs at the present day.
It has been shown that the mantle cavity in Brachiopods is physiologi-
cally and sometimes morphologically divided into two compartments.
This condition is absent in Lamellibranchs, where the mantle cavity in
all forms is physiologically entire. It is true that in all Lamellibranchs
the mantle cavity is divided either temporarily or permanently into
inhalent and exhalent chambers by the gill (see 1), but a corresponding
temporary division occurs in both compartments of the Brachiopod shell
when the animal is feeding. The nearest approach in Brachiopods to the
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914. U
308 J. H. ORTON.
siphonate forms in Lamellibranchs is probably represented by members
of those genera in which the postero-lateral angles of the shell are very
much drawn out, as in Productus qiganteus, Spirifer verneuilli, and species
of Lepteena and Platystrophia, and in other forms common in the
Rhynchonellidze, in which the front middle part of the shell is differ-
entiated from the rest in such a way as to resemble a siphon (see Fig. 8, C,
p. 296). Inall these forms it is highly probable that the shell modifications
are correlated with localization of the food-currents. Lingula, however,
has been shown by Morse (7) to dispose the mantle sete in such a way
that they form a sort of temporary siphon for the ingoing and the out-
going currents, and this method of forming siphons may occur in other
Brachiopods.
From the description of the Brachiopod lophophore given in the pre-
ceding pages there can remain no doubt that that organ is analogous
to the gill of Lamellibranchs, as has indeed already been observed by
Lankester (12). The resemblance in appearance of the lophophore to
the palp of a Lamellibranch such as Nucula is indeed close, but that
the resemblance is superficial will have been seen from the foregoing
account of its function. Hence, if the organs can be compared at all
Morse is undoubtedly wrong in comparing the lophophore as he does (13)
with the Lamellibranch palp. Thus it is seen that on the whole the parallel
developments of organs in the Brachiopods and Lamellibranchs are
much fewer than might have been expected from the similarity in their
mode of feeding, and the differences which do exist may probably be
very largely due to the absence in Brachiopods of that consolidation of
the gill-filaments which appears to have played such an important part
in the evolution of the Lamellibranchs.
SUMMARY.
Brachiopods feed in the same way as some Gastropods, as, for example,
Crepidula, most Lamellibranchs, Amphioxus, and Ascidians, that is, by
establishing a current of water through certain spaces bounded by the
body, and sieving off the food-particles contained in that current by
means of the lophophore and its cirri.
The cilia on the gill-filaments (cirri) are differentiated in Brachiopods
into lateral and frontal cilia, in essentially the same way and with the
same functions as in some Gastropods, most Lamellibranchs, Amphioxus,
Balanoglossus, and some Ascidians.
The main current through the mantle cavity in Brachiopods is pro-
ON CILIARY MECHANISMS. 309
duced chiefly by rows of lateral cilia on the cirri, or gill-filaments, but
cilia on the body of the lophophore and on the mantle assist in main-
taining this current, which in Crania enters the mantle cavity in the
antero-lateral regions of the shell at each side and is expelled in the middle
front part of the shell. The mantle cavity in Brachiopods is divided
physiologically into two compartments corresponding to the bilateral
symmetry of the lophophoral spirals. In some Brachiopods the mantle
cavity is also divided morphologically into two compartments, either by
medium antero-posterior septa or by actual bifurcation of the whole shell.
Food-collection is effected in Brachiopods mainly by the frontal
cilia on the gill-filaments, but tracts of cilia on the filamentar side of the
lophophore assist in capturing food-particles. The captured food from
both these sources is passed into the well-known food-groove on the
lophophore and thence to the mouth.
For the capture of food-particles mucus is secreted on the frontal
epithelium of the gill-filaments, at the bases of the gill-filaments, and on
the body of the lophophore. A selection of the finer food-particles is
effected in Brachiopods to some extent in the lower parts (inhalent
chambers) of the mantle cavity ; the heavier undesirable particles being
collected on the mantle lobe from which they are expelled from the pre-
cincts of the animal.
Some of the characters of the shells of many fossil and recent Brachio-
pods can be partially explained from the fact of the physiological sub-
division of the mantle cavity.
The cephalic gills of Cryptocephalous Polychztes have current-pro-
ducing lateral cilia and frontal food-collecting cilia essentially similar to
those of Brachiopods, Lamellibranchs, and the other groups mentioned
above. In Phoronis there is also a similar differentiation of cilia on the
lophophoral cilia, but so far as this animal has been examined the func-
tions do not appear to be quite the same as in the other groups
examined.
Thus the ciliary mechanisms on the gills of many Gastropods, most
Lamellibranchs, Amphioxus, Ascidians, Brachiopods, and the Crypto-
cephalous Polycheetes are essentially similar, and in the three groups to
which these animals belong the same mechanism—and similar gill-filament
supports—have arisen independently to meet similar or the same require-
ments, and thus afford an interesting example of parallel evolution.
An endostyle is present at the base of the gill in Crepidula, Calyptrea,
and probably also in Capulus. This endostyle of Crepidula shows a
remarkable resemblance to that of Amphioxus and Ascidians and
310 J. H. ORTON.
serves the same purpose, that is, it secretes mucus which is passed on
to the gills for the entrapping and the transportation of food-particles.
On the right side of the endostyle of Crepidula is a cilated groove,
which carries mucus and some food-particles forwards to serve for
catching and expelling the heavier food-particles which enter the front
portion of the inhalent chamber.
The independent origin of essentially the same ciliary mechanisms in
Molluscs, Protochordata, Brachiopods and some Polychetes, and of a
similar glandular organ, the endostyle in Crepidula and Amphioxus and
Ascidians, are facts which add greatly to the difficulty of determining with
any certainty what are homologous organs in different animals. It also
follows that similar organs occurring in different animals and having the
same function are never necessarily homologous.
The adaptation in Brachiopods and Lamellibranchs to the process of
feeding are compared, and the suggestion is made that the present
decadent condition of the former group is due to the absence of that
consolidation of the gill and correlated modification of the mantle which
appear to have conduced to the present relatively flourishing condition
of the Lamellibranchs. .
REFERENCES.
1. J. H. Orton. The Mode of Feeding in Crepidula, with an account of
the current-producing mechanism in the mantle cavity, and some
remarks on the mode of feeding in Gastropods and Lamellibranchs.
Journ. M.B.A. Vol. 9, No. 3. 1912.
2. J. H. Orton. The Ciliary Mechanisms on the Gill and the Mode of
Feeding in Amphioxus, Ascidians, and Solenomya togata. Journ.
M.B.A. Vol. 10, No.1. 1913.
3. J. Hérouard. Sur les Courants de Nutrition des Brachiopods. Journ.
de Conchyliologie, Paris. 3 Sér., Tome 17. 1877.
4, A.E.Shipley. On the Structure and Development of Argiope. Mittheil.
Zool. Sta. Neapel. IV. 1883.
5. A. E. Shipley. Molluscs and Brachiopods. Cambridge Nat. Hist.
Vol. 3, pp. 463-488. 1895.
6. J. F. Van Bemmelen. Untersuchungen tiber den Anatomischen und
Histologischen Bau der Brachiopoda Testicardinia. Zeit. fur .
Naturwissenschaft. Jena. XVI, N.F. IX, 1, 2. 1883.
7. E.S. Morse. On Japanese Lingula and Shell Mounds. Amer. Journ.
of Science and Arts. Series 3, Vol. 15, p. 157. 1878.
ON CILIARY MECHANISMS. ri i
Ph. Francois. Choses de Nouméa. Arch. de Zool. Exp. et Gén.
Sér. 2, Tome 9, p. 233. 1891.
W. A. Herdman. Cambridge Nat. Hist. Vol. VII. Fishes and Asci-
dians, p. 47. 1904.
F. Blochmann. Untersuchungen iiber den Bau der Brachiopoden.
Jena. 1892-1900.
G. C. Bourne. On the Anatomy and Systematic Position of Incisura
(Scissurella) Lytteltonensis. Q.J.M. Sc. Vol. 55, p. 7. 1910.
. Ray Lankester. Ann. & Mag. of Nat. Hist. Series 4, Vol. XI, p. 93.
. 8. Morse. Systematic Position of the Brachiopods. Proc. of Boston
Soc. of Nat. Hist. Vol. 15, p. 31. 1873.
D. P. Oehlert. Brachiopodes. Manuel de Conchyliologie, by P. Fischer.
Paris. 1887. p. 1212.
. Willey. Zoological Results. Part IIT, p. 324. 1899.
. Ray Lankester. On the Use of the term Homology in Modern
Zoology, and the Distinction between Homogenetic and Homo-
plastic agreements. Ann. & Mag. Nat. Hist. 4, Vol. 6, p. 34. 1870.
eS &
>
[3124
Preliminary Account of a Contribution to an Evaluation
of the Sea.
By
J. H. Orton, B.Sc., A.R.C.Sc.,
Naturalist at the Plymouth Laboratory.
TABLE OF CONTENTS.
PAGE
Introduction ; : ; A : F : ; oe
Rate of Growth in some Gislentocatat : 313
Rate of Growth in some Porifera and the life- Metae of Sam Grantia, ‘and Waa:
solenia : : : : 3 : : ‘ . 314
Rate of Growth in some Biety helnihes : 5 : C e : ‘ . 3l6
Rate of Growth in some Annelida. : : A : : ae 5 Bll
Rate of Growth in some Polyzoa : 5 Z c : : é : . 316
Rate of Growth in some Crustacea. : : ; ; ; é 5 5 Billy
Rate of Growth in some Mollusca s : "6 Z é : : & ayllts!
Rate of Growth of Crepidula fornicata : : : : 3 é : . 320
The age of sex-change in C. fornicata : : ; : : . . 322
Rate of Growth of Oyster spat in the first summer ‘ : . : . 323
The life-history of Galvina picta : : c 6 . : . 9323
The life-history of Ciona, Clavellina, and Necidiolla : : : . c . 324
Rate of Growth in some other Tunicates . : 2 : : : : . 325
Rate of Growth in Saccorhiza bulbosa ; 5 ‘ : c : : 3826
Summary . ; c : c A : : ; : : : . 326
INTRODUCTION.
AN investigation of the rate of growth in Marine Invertebrates was
begun in 1911, and a large amount of material the age of which is known
has now been collected from various sources. The particular objects of
this research are: (1) to establish the age of common marine inverte-
brates, (2) to determine the minimum age at which these forms begin to
breed, (3) to examine the rate of growth at different seasons of the year
and under different conditions, (4) to investigate the fecundity of different
forms so far as possible, and (5) to collect the scattered literature on
these subjects.
The investigations have been carried on mainly by immersing various
objects in the sea at a known time and subsequently observing and collect-
CONTRIBUTION TO AN EVALUATION OF THE SEA. 551 IB)
ing the various kinds of animals growing on them. Other experiments,
however, are being carried out with some success with the object of
entrapping young or larval free-living animals and observing their rate
of growth. The sexual condition of the collected animals has been
noticed particularly, and evidence of the maturity of the sexual products
obtained either by isolating the animals or by trying artificial fertilisa-
tions. As a result of these investigations a good deal of information
about members of most of the groups of invertebrate animals has been
obtained, and the following statements may be regarded as a sample of
the results.
RATE OF GROWTH IN SOME CQLENTERATA.
Among the Ccelenterata it has been found that various species of
Obelia and Clytia Johnstoni give off medusz when not more than a month
old. Similarly, Bougainvillea ramosa yielded meduse at once when
collected at an age of not more than six weeks and a few days. In all
these cases, however, the observations do not cover the whole life-cycle
as do the followimg. The commonest species of Tubularia—almost
certainly 7. larynx—has been found to give off actinule larve at an
age of not more than six weeks, and in one experiment this species had
moderately developed gonophores at an age of not more than 26 days.
As these Tubularia actinulee have been found to settle and grow into little
polyps within a few days, it follows that this species may pass through its
life-cycle within about six weeks and probably actually within four or five
under favourable conditions. In the same way Plumularia and Gono-
thyrea have been found to give off planule at an age of not more than
three months; thus, as these planule may probably settle almost imme-
diately, these hydroids may complete their life-cycle within at least
three months, and in both cases in a period probably less than that stated
by some few weeks. Hence there can be little doubt that these hydroids
pass through several generations—probably three and possibly more—
in a year. A species of Syncoryne yielded meduse at a maximum
age of ten weeks, but doubtless the actual age was much less than
this.
In all these cases, however, there can be little doubt that the rate of
etowth—probably apart from the question of food-supply—varies at
different times of the year. So far as the investigations have been
examined, it would appear that in this group most of the species men-
tioned above appear to have a maximum rate of growth in the months
of August and September.
314 J. H. ORTON.
The most interesting record of the rate of growth obtained so far in
Actinians is that of Sagartia viduata, which has been found to attain to
full size at a maximum age of 14 to 15 months.
RATE OF GROWTH IN SOME PORIFERA AND THE LIFE-
HISTORY OF SYCON, GRANTIA, AND LEUCOSOLENTA.
Among Porifera a fairly complete investigation of the life-history
and rate of growth of Sycon coronatum, Grantia compressa, and a species
of Leucosolenia has been made. These sponges have been found to be
annuals, as they have generally been believed to be. But the interesting
fact has been ascertained that there are two breeding seasons, especially
well marked in S. coronatum and Leucosolenia, one in summer and
one in late autumn. Data have, moreover, been obtained supporting
the view that the same specimens may breed twice in their life-history,
namely, once in late autumn and again in the following summer. Thus,
therefore, it would seem that temperature is the main factor governing
reproduction in these animals, since continuous rapid growth takes place
in the winter, as will be seen from the following observations. Some
very fine specimens of S. coronatum of known age have been obtained.
One exceptionally fine specimen attained a length of more than 28 cms.
with an average width of about 2-2 cms. in not more than 10 months
19 days, and growing during the period from July to May. Another
specimen 24-8 cms. long grew between June and January in a period
not longer than 7 months and 20 days. In another case several specimens
measuring between 14 and 16 cms. long grew between May and January
in a period not longer than 8 months and one day. It is an interesting
fact that none of these specimens yielded embryos when they were
isolated in dishes of sea-water, whereas tiny specimens from 3 to about
5ems. taken in September and October gave off a good number of
embryos. These tiny specimens have been obtained from several
independent experiments started in early and late spring and in the
summer, hence they are the sponges derived from the embryos liberated
at the summer breeding period, namely, about the latter end of May or
early June. The approximate age of these specimens is therefore about
four months ; in one case the actual age of such specimens was not more
than 15 weeks. It is highly probable, moreover, that these autumn
breeding forms continue to grow through the winter and again give off
embryos in the following summer, when they die down. However this
may be, there can be no doubt that there are at least two broods of
CONTRIBUTION TO AN EVALUATION OF THE SEA. 315
embryos produced in a year, and from the fact that specimens only
1-5cms. long have been found to contain fully developed free embryos
in the inner flagellated chambers in the autumn I think it very probable
that this species might in favourable seasons yield three generations
within a year, rushing through two of them in late autumn.
Similar breeding phenomena to those described in S. coronatum
are presented by G. compressa and Leucosolenia. Tiny specimens
of G. compressa 1:3 cms. long taken in October at an age not greater
than 7 months and of an actual age of less than 4 or 5 months have been
found to be crammed full of embryos, while large specimens 8 cms. long
with an average width of 3-5 cms. taken in March and April have been
found to contain only immature ova. In the following June, however,
specimens similar to the latter have yielded crowds of embryos. Cor-
responding results to these have been obtained with Leucosolenia.
Thus the summer and winter breeding periods appear to be general in
our calcareous sponges. The life-cycle of Grantia has been carefully
followed round the year, and it was observed that in one situation where
this sponge was extremely common of a large size in June they gradually
disintegrated during July, so that by August it was impossible to find
any but the tiniest specimens, which were doubtless the first comers of
the new summer crop. The same difficulty in finding any but small
specimens was also met with on other grounds in the district where
these sponges can generally be obtained at any other time of the
year.
The summer crop continues to grow during the autumn, and by about
December may attain to an area in side view, i.e. on one flat side, of
about 10 sq. cms. By the following March specimens may be found
with an area of from 25 to 30 sq. ems.,* and at the end of a year’s growth
in the following June specimens of average size may attain to an area
of at least 30 sq. ems.* in side view, or in other words, the whole “ body-
wall’ would have an area of more than 60 sq. cms. After delivering
their summer embryos these specimens, as we have already seen, die
down and a fresh crop arises.
Of siliceous sponges few records of much value have so far been
obtained, but a colony of Halichondria panicea grew on a flat suriace
between June and the following January to an area of about 45 sq. cms.
and of about the usual thickness of this sponge.
* More exact measurements will be given later.
316 J. H. ORTON.
RATE OF GROWTH IN SOME PLATYHELMINTHES.
Among the Platyhelmia strong indications have been obtained that
Cycloporus, Leptoplana, and their allies pass through a generation
within a few months, but no certain evidence has been obtained with
regard to these animals. The results will be more fully discussed later.
RATE OF GROWTH IN SOME ANNELIDA.
A good deal of information has been obtained of various members of
the Annelid group, and especially of the sedentary Polychetes. Pomato-
ceros trigueter and Hydroides norvegica grow to nearly full size in about
4 months, and at this age the former has yielded in many cases practi-
cally 100 per cent of embryos on being artificially fertilized, while a
specimen of Hydroides of the same age shed ripe eggs, but unfortunately
no male of the same age was available for a fertilization. The common
species of Filograna has been obtained, carrying ripe eggs and trocho-
spheres at an age probably less than four months, having grown through
the summer. About the same time another experiment yielded speci-
mens with fully developed eggs at an age not greater than 10 weeks and
4 days. Later in the year full-sized specimens with buds had an age
not greater than 4 weeks and 2 days. There can be little doubt, therefore,
that in this species there is an alternation of generations, the summer
forms producing eggs and sperm and the autumn and winter ones
producing buds.
Polymnia, Dasychone, and many others have been found to attain
a good size in much less than a year. Ripe Serpula vermicularis not
more than about 10 months old yielded an excellent result on being
fertilized. Dinophilus has been reared through at least one generation
in the Laboratory within a period of 7 weeks, and Ophryotrocha to a
medium size in 8 weeks, but with more attention doubtless the rate of
growth in these two forms might easily be found to be twice as great.
Cheetopterus at an age less than 13 months grew a tube 14 cms. long and
had developing ova in its gonad, and Sabella pavonina a tube 12-6 cms.
long in less than 31 weeks, and at this age contained well-developed but
not quite mature ova. Similar results have been obtained with many
free-living Polychetes, but these will be discussed later.
RATE OF GROWTH IN SOME POLYZOA.
One interesting result has been obtained among the Polyzoa. By
continued experiments and observations Bugula flabellata* was found
* Including Bugula calathus, Norman, for the purpose of the present paper.
CONTRIBUTION TO AN EVALUATION OF THE SEA. SAW f
to grow to a good-sized colony and give off larvee within a period of not
more than 8 weeks. From the observations made there is no doubt that
this species passes through several generations during the summer and
autumn, and indications were given that the most rapid growth occurs
during August and September. In one case more than 100 zooids were
counted in a colony not more than a fortnight old. Another species ot
Bugula has been found to grow colonies 4 cms. high and 2-5 cms. wide in
15 weeks. Very large colonies of a Bowerbankia species of an age not
more than 9 months gave off a great number of larvee, and in another
experiment a colony 4-5 cms. high and 2-5 cms. wide was obtained at an
age not greater than 15 weeks. Scrupocellaria reptans formed good-
sized colonies in less than 7 months ; Membranipora membranacea grew
to a circular colony 6 cms. in diameter within 12 weeks, Lepralia palla-
siana circular colonies 1-1 cms. in diameter within 8 weeks, and 3-1 ems.
in diameter within 23 weeks. Cellularia neritina grows into huge colonies
in the inner basin at the Great Western Docks in a year.
RATE OF GROWTH IN SOME CRUSTACEA.
A few observations have been made on members of the Crustacea,
mostly of the sedentary forms.
Balanus balanoides attains to full size in a year and gives off large
numbers of nauplii at this age, but there does not appear to be more
than one breeding season, namely, in the late winter months. Other
species of Balanus, however, have been found to grow to a large size in
less than a year. Especially interesting results have been obtained in
this group by examining the bottoms of ships in dry dock and obtaining
information from the captain of the ship as to when the ship was last
scraped and painted. From the information obtained in this way it has
been found from independent data that Conchoderma virgata grows to a
good size and gives off nauplii within from 4 to 5 summer months, and
Lepas anatifera and L. hilli within the same period. Conchoderma
aurita grows to a large size, namely, 7 cms. long, within 5 months,
but was not found with embryos or nauplii when examined. This rapid
growth of Cirripedes is well known to some captains of sailing vessels,
who are constantly sailing the high seas in relatively slow-moving boats,
for there is apparently a limit to the speed of the boat on which Lepas
and Conchoderma will grow. The vessel on which the specimens
mentioned above were obtained had travelled mostly at 6 to 8 knots I
was told, hence the limit of speed for their growth must be something
greater than this.
318 J. H. ORTON,
In this group a special experiment has been tried with success, with
the object of entrapping young forms in a wire basket of a small mesh
inside which, as the animals grow, they become imprisoned. Food is
obtained by the animals from the natural growth on the wire basket and
the surrounding parts. The wire basket was placed in a large floating
wooden raft in Cawsand Bay adjacent to Plymouth Sound. From this
cage put out in the sea on the 28th May, 1913, and taken in on 26th
February, 1914, were obtained Palemon serratus measuring on the
average about 5-6 cms. long from the tip of the rostrum to the end of the
tail, and two Portunus puber, one a male with a carapace width of
3-5 cms. and one female whose carapace measured 3-3 cms. wide.
As the greatest width of the mesh of the wire cage at the close of
the experiment was 145 mms., by 9 mms., it follows that the
specimens of Portunus were in all probability samples of the young
for the season of 1913, since the breeding season of this species of
Portunus falls in about the spring of the year. (See “ Plymouth Marine
Invertebrate Fauna,” p. 257, J.M.B.A.,N.S., Vol. VII, No. 2, 1904.)
It is highly probable that the specimens of Palemon serratus entrapped
in the cage were also examples of last year’s crop of this species, and as
specimens about the size they attained occur in berry there would appear
to be little doubt that this species becomes mature and bears young
within a year. Some specimens are being kept alive in the tanks with a
view to watching their subsequent growth.
An experiment conducted on similar lines on the Essex coast (see pp.
320 and 322) with a wire cage, the greatest width of any mesh of
which at the end of the experiment was less than 2 cms., yielded four
specimens of Carcinus menas, three males and one female. The width of
the carapace of the three males was respectively 3-6, 3-4, and 3-2 cms., and
that of the female 3-lems. This experiment extended over a period of
15 weeks between the 18th June and the 3rd October. Hence there
can be little doubt that the common crab also attains to maturity within
a year. Further experiments will be made with cages of wire having a
smaller mesh in the hope of following the rate of growth more fully in
these and other species of Crustacea:
RATE OF GROWTH IN SOME MOLLUSCA.
In the Mollusca group the age at which several species begin to breed
has been determined. The common mussel, Mytilus edulis, has been
found to spawn naturally at an age of one year. From eggs spawned in
this way a fertilization made by adding sperm from a male of the same
CONTRIBUTION TO AN EVALUATION OF THE SEA. 319
age yielded 100 per cent of fertilized eggs. At this age the commonest
sizes are from 3-5 to rather more than 4cms. A good deal of material of
this species has been obtained continuously during a period of two years,
so that it will be possible to work out the rate of growth in this important
molluse fairly thoroughly. From several independent experiments it has
been found that MW. edulis may grow in this district to a size of from 3-5
to 4cms. within the period between April and November, i.e. in about
30 weeks. During the winter it would appear that relatively little
growth takes place. By the followmg April, however, specimens may
attain to the size of upwards to 5cms., and at the end of the summer
following that in which the animals were spawned, 1.e. at an age of about
18 months, the average length of specimens is about 5cms. with a
corresponding increase in width and depth, while one specimen of this
age attained a length of 6-8 ems. and a width of 3-4 cms. The variations
in size at different ages will be given later. An interesting comparison
has been made between mussels 3-5 cms. long and about 10 months old
and thick-shelled mussels from 1-3 to 1-6 cms. long from the exposed
shore at Whitsand Bay. The latter were quite ripe and gave good
fertilizations, whereas at the same time the former were not ripe. Thus
it would seem that the Whitsand Bay specimens really were dwarfed
individuals of an age of at least two years.
Continuous observations have also been made on the rate of growth
in a few individuals of the common limpet, Patella vulgata. It has been
found that specimens may attain a size of 4 cms. in less than 15 months,
and at this age are ripe. An artificial fertilization made from these
specimens gave ultimately a fair percentage of trochospheres. During
31 weeks between the 27th January and the 2nd September, 1913, two
specimens grew on a flat surface, respectively, from (a) 2-1 cms. long by
1-6 cms. wide to 4:1 cms. long by 3-3 cms. wide, and (b) 3-8 cms. long by
3-2cms. wide to 5-3cms. long to 4-5cms. wide. Thus the smaller
specimen increased 2 cms. in length and the other 1-5 cms. in length.
The age of the latter specimen when 5-3 cms. long was not more than
two years. Another specimen grew between April 4th and September
2nd in the same year from 2-25 cms. long by 1:7 cms. wide to 3-3 cms.
long by 2-85 ems. wide, thus increasing in length 1 cm. within 20 weeks.
_Thus the rate of growth of P. vulgata in this district 1s much greater—
as indeed might be expected—than that found by Russell* in Scotland.
These observations are, however, being continued, and the results in
* E.S. Russell, ‘‘The Growth of the Shell of Patella vulgata,” Proc. Zool. Soc., 1909,
p. 235, I.
320 J. H. ORTON.
relation to those obtained by Russell will be discussed later when more
data are available.
Anomia aculeata has in several independent experiments been found
to attain to an average size for this species and to give larve on being
fertilized at an age of less than four months. Specimens of this age have
been taken at various times of the year with the same result, hence this
species undoubtedly passes through two and probably three generations
within a year. Next to the common mussel this is probably the
commonest mollusc on our shores.
The boring mollusc, Teredo navalis, has been tound to grow to a length
of 19-8 cms. in 31 weeks, and made borings in soft wood 28 cms. long
with an average width of about lem. It was also found that the gill was
alive in specimens obtained a fortnight after the wood in which they
were living was taken out of the sea. Thus these animals would be
able to live easily during the period during which most vessels would be
in dry dock for scraping and painting, hence, as is well known but not
always fully realized, it is highly important that wooden vessels should
be constantly cleaned to prevent the attacks of this destructive mollusc.
THE RATE OF GROWTH OF CREPIDULA FORNICATA.
By means of a grant from the Royal Society a number of special
experiments were carried out during the year of 1913 off the Essex coast
with the object of determining the rate of growth in Crepidula. For
this purpose a floating raft containing shells and tiles was moored at the
mouth of the River Blackwater in the expectation of catching the spat.
In putting out the raft and taking it in again in the autumn the Directors
of the Tollesbury and West Mersea Oyster Company very kindly placed
at my service the valuable help of their fishermen and their boats, and I
wish here to express my thanks to them for the facilities they gave
me in carrying out the experiment. The design of the experiment
succeeded, and Crepidula spat was obtained on the raft and on the
material placed in the raft, but unfortunately this success was marred
by the fact that the raft had probably been touching the bottom of the
river a few days when I went to examine it. It is therefore possible but
not probable that some of the spat obtained on the raft may have crept
on to it. Hence it is hoped to try the experiment again this year. From
the position of some of the spat on the raft and on the tiles in it there
was no doubt that they had been settled there some time, and therefore
before the raft touched the bottom, and as the specimens obtained were
all of sizes similar to the smallest sizes obtainable on the grounds in the
CONTRIBUTION TO AN EVALUATION OF THE SEA. 321
district, and, further, since the size of the spat is what might be expected
from the following experiment and other observations, there can be little
doubt that they had settled on the raft and had grown in position, and
are therefore examples of the spat for that season. The spat obtained
varied in length from 4-5 mms. to 14 mms., and altogether 15 specimens
were obtained. Their average length was 8-1 mms. and their average
breadth 6-4 mms. Since they had grown during the time the raft was in
the sea, namely, from June 16th to October 2nd, their greatest possible
age is 15 weeks.
At the same time as the experiment described above was begun another
experiment suggested by Mr. J. Bean, of West Mersea, was started for the
purpose of observing the rate of growth in the sea of young specimens
which were considered almost certainly a year old. For this experiment
Mr. Bean very kindly gave me the use of two of his oyster trays—which
are shallow wooden trays with one side covered with perforated zinc
and the other with small-meshed wire-netting—and also provided new
wooden posts, which are driven into the mud to carry the trays. The
trays were filled with shells and tiles secured to one side of the tray and
a number of young Crepidula were put on to the shells. A few older
specimens were marked and the shells on which they were sitting secured
to the tray. The total number of young specimens put in the tray was
131, and their average length 10-7 mms. They varied in size from 5 to
15 mms., but the commonest sizes were about 9 to 12 mms. These young
ones were put in the trays on June 18th and examined again on the 3rd
of the following October. When examined at the latter date a number
of them were found dead in the bottom of the tray and only 28 could be
found alive. These remaining specimens varied in length from 1-4 cms.
to 2-65 ems., and their average length was 2-1 cms., but 17 of them were
more than 2cms. long. It is quite clear, however, that within the
period of the experiment, namely, 15 summer weeks, Crepidulas about
1 cm. long grow to a length of two centimetres. Hence the spat obtained
in the former experiment may be regarded as a fair sample of the spat for
the season of 1913. Thus during the summer Crepidula spat grows to a
size of about a centimetre and appears to grow little during the winter, as
indeed was found by examining batches of the tiniest specimens pro-
curable on the grounds in the autumn and in the following late winter.
During the next summer the young slipper-limpets may grow to a length
of about an inch. This experiment is being continued and it is hoped to
follow the rate of growth further. Of the few larger marked Crepidula
put in this tray only two specimens showed an increase in size. One
322 J. H. ORTON.
specimen grew from a length of 25 mms. and a width of 17 mms. to a
length of 29 mms. and a width of 20-5 mms. ; the other one grew from a
length of 28 mms. and a width of 13 mms. to a length of 33-5 mms. and
a width of 26 mms. It is thus seen that C. fornicata may grow to a length
of at least 3 cms. within 23 years, but it is desirable that the rate of
growth should be observed in a larger number of individuals than was
possible under the conditions of these experiments.
THE AGE OF SEX-CHANGE IN CREPIDULA FORNICATA.
In the tray experiment just described it was found that some of the
small Crepidula had formed chains of two individuals, and in one case
two specimens had put themselves in chain with one of the larger marked
Crepidula to form a chain of three. When measuring these slipper-
limpets their sex condition was also recorded and the singular fact
established that while the individuals in chain were quite vigorous males,
those which were leading a solitary life were changing from males into
females. This phenomenon had indeed been suspected from the exten-
sive examinations which have been made from time to time during the
last few years on batches of Crepidula. The condition of these small
Crepidulas may be gathered from the following records in which the
abbreviations used in an earlier paper* are again adopted. The solitary
specimens were recorded as follows : 8 specimens 3 p.sm.; 3 9 p.tr.; one
p-r.ut.r.; 29 ut.sm.p.tr.; 4 or 53. In the chains formed by the small
specimens (one year old forms) the sexes were recorded as follows: (1)
AGpr., Bd; (2) AG utr.? p.xr., Bg. The chains formed by the small
specimens with the larger marked specimens, which in all cases are the
A’s in the chain, were recorded as follows: AJ sex not recorded, B 3,
C$; All¢@ptr, BS; AIVE ptr., BS. Thus in all cases where the
young Crepidula had formed chains they retained their characters as
males, whilst 14 out of 19 that remained solitary had begun to change
their sex. Thus the absence of association with their fellows in chains
undoubtedly results in a more rapid change from the male condition to
the female condition than in the cases where the Crepidulas are able to
form chains. Sex-change in Crepidula therefore may take place in the
second year of the life of isolated individuals.
* J. H. Orton, “On the Occurrence of Protandric Hermaphroditism in Crepidula
fornicata,’ Proc. Roy. Soc. B., Vol. 81, 1909.
The meaning of the abbreviations used above is as follows :—
p-sm.= penis small; p.tr.= trace of penis; p.r.= penis rudimentary.
ut.sm.=uterus small; ut.r.= uterus rudimentary.
CONTRIBUTION TO AN EVALUATION OF THE SEA. 323
THE RATE OF GROWTH OF OYSTER SPAT IN THE
FIRST SUMMER.
Besides the two experiments described above two other independent
ones were carried out, but without success, for the purpose of catching
Crepidula spat. These experiments, however, were successful in catching
a large amount of oyster spat and other marine invertebrates, and in one
case a few spat of the common cockle, Cardiwm edule, which are of much
interest, were obtained. Measurements of the oyster spat have been
made and a growth curve will be given to show the variation in size in
spat of all ages up to 10 and 15 weeks. The limits of size of the 10-weeks’
spat—as determined by the area of one valve—are from about 2 sq. mms.
to 175 sq. mms., and the commonest size appears to be about 75 sq. mms.
The largest specimens of 15-week spat have an area of about 250 sq. mms.,
i.e. about a square inch. Samples of these oysters are still beg kept
under observation with the object of observing their subsequent rate of
growth and the age at which they begin to spawn. |
The spat of the C. edule mentioned above varied in their greatest
breadth between 2-4 mms. and 8-4 mms. and their greatest age is 15
weeks. Other observations on this mollusc, however, are being carried
out with the object of following more fully the rate of growth, and par-
ticulars will be given later.
A large collection of various molluscs has also been made with a view
to investigating their age from the periodicity of the main lines of growth.
Some success has already been obtained with Patella vulgata, C.
formcata, C. edule, and the fresh-water mussel, Anodonta cygnea, in all
of which the periodicity of growth is well marked. In all these cases,
however, it is important to establish the rate of growth during the first
season, and, as has already been noted above, valuable information in
this respect has been obtained for Crepidula, Patella, Mytilus, Cardium,
and Ostrea.
THE LIFE-HISTORY OF GALVINA PICTA.
Some remarkable facts relating to the life-history of the Nudibranch
Molluses have been obtained, and the following case may be taken as an
example. The raft moored in Cawsand Bay—mentioned above—was
visited six weeks after it was put out in the sea. It was found to be
covered with a large scattered growth of the hydroid Obelia geniculata, on
which the adult Nudibranchs, Galvina picta, G. exiqgua, Tergipes despectus,
G. farrani, and young Facelina drummondi and Doto coronata were feeding.
NEW SERIES.—VOL. X. NO. 2, JUNE, 1914. x
324 J. H. ORTON.
G. picta was the dominant Nudibranch, and 53 specimens were brought in
and measured. Their average length from tip of head to end of tail was 11
mms., and they varied in length from 7 to 17 mms. Masses of spawn of
both G. picta and exiqua were present on the hydroids, and from these
masses free-swimming veligers were being given off. Thus these Nudi-
branchs had undoubtedly peopled the raft as veligers, rushed through
theirdevelopment atthe expense of the hydroid,and were giving off veligers
againto populate hydroidselsewhere within a period notlonger than6 weeks
and 2 days. Such a rapid growth is very probably a necessity for hydroid-
feeding organisms, since the hydroids themselves attain maturity very
quickly. In this respect it is also of great importance to the race that
some Nudibranchs are protandric hermaphrodites,* for by this means a
few individuals are able to multiply rapidly where food is abundant, and
thus the race by means of its free-swimming larve is frequently able to
utilize an abundant food-supply wherever such is available.
THE LIFE-HISTORY OF CIONA, CLAVELLINA, AND
ASCIDIELLA.
In the group of Tunicata the rate of growth in many species has been
thoroughly worked out. Ciona intestinalis, Ascidiella aspersa, Molgqula
ampulloides ? have all been found to be ripe and yield embryos on being
artificially fertilized at an age of not more than 3} months, and in some
cases have themselves extruded fertilized eggs. Better fertilizations
of these forms are, however, obtained from specimens about 44
months old. At an age of less than 15 weeks Ascidia conchilega
from the Essex coast also gave 100 per cent of tadpoles on being
artificially fertilized. Large numbers of successful artificial fertilizations
were made in this group in running down the minimum age at which
tadpoles can be obtained, and it was generally noticed that cross-
fertilizations gave better results than self-fertilizations. All these
species, however, grow at a much greater rate in the summer and autumn
than at any other time of the year, and in the months of August and
September Clavellina lepadiformis and Leptoclinum (Diplosoma) gelati~
nosum grew from the tadpole to a tadpole-bearing adult within 8 weeks.
In one remarkable case L. gelatinosum was found to have raced through
the whole life-cycle from the tadpole to an adult form giving off tadpoles at
an age not greater than 3 weeks and 5 days. And indeed about this time
of the year, August, this compound Ascidian is to be found overgrowing
almost everything, both about and below low-water mark.
* As has been found by the writer in researches in this group.
CONTRIBUTION TO AN EVALUATION OF THE SEA. 325
The life-history of C. intestinalis is very similar to that of the
Sycons described above. It has been definitely established that the
species dies down about October, at about which time very fine
specimens upwards to a foot long can be obtained. This fact has,
however, been known at this laboratory for several years. By the
end of October it is difficult to find Ciona of even medium size, but
very small specimens are not uncommon. Breeding commences again
after the winter season about April, and from April to October specimens
may attain to a length of 15 cms., while those which have wintered and
are practically a year old at this time have been found to attain a length
of 30 cms. It is thus evident that Ciona is an annual, but passes through
at least two generations in a year, and in favourable seasons may yield
three, rushing through two generations in the autumn, as in the case of
the Sycons. Thus these observations support the statement made by
Anton Dohrn that Ciona at Naples passes through three generations in
a year. (See footnote, p. 326.) The life-history of C. lepadiformis has been
found to be very similar to that of C. intestinalis. It appears in this dis-
trict about the end of April—apparently growing from dormant stolons
—and grows to huge colonies during the summer, and at the same time
passes through at least two generations. At about October these colonies
die down and nothing is to be seen of them during the winter until about
the following April.
A. aspersa has a somewhat similar life-history, but does not
die down as completely in the autumn as Ciona. Between April and
September this species has been found to grow to a length of 9 cms.,
very nearly the maximum size. M. ampulloides? has also a very
similar life-history to that of Ascidiella, and gives quite good fertiliza-
tions at an age of 3 months, and this sub-spherical Ascidian may
attain at this age a diameter of 2-5 cms., a size not far from the maximum
for this species.*
RATE OF GROWTH IN SOME OTHER TUNICATES.
Botryllus violaceus gives off larve at an age not greater than 3 months
and grows to large colonies during the summer. Thus in the case of all
these Ascidians there are at least two crops of larvee produced in a year,
and in some of them, as in Leptoclinum, Clavellina, and Botryllus, there
may be three or more crops in favourable seasons.
* Development in this species is remarkably rapid; the fertilized egg developing into
a metamorphosing larva in less than 24 hours.
326 J. H. ORTON.
It is interesting that the maximum rate of growth in this group occurs
at about the same time of the year as that found in the Sycons, some
Polyzoa, some Molluscs, and some Hydroids. This period of maximum
rate of growth occurs about August and September, and it is hoped that
when the whole of the material collected has been worked out that it will
be possible to estimate more accurately the rate of growth for different
times of the year in all the groups.
RATE OF GROWTH IN SACCORHIZA BULBOSA.
A few marine alge have been collected in the course of the experiments,
and so far the most interesting growth obtained is that of Saccorhiza
(Laminaria) bulbosa, which between April and October, a period of 7
months, was found to grow a lamina 3 to 5 feet long and a sub-
spherical base about 5 inches in diameter.
SUMMARY.
From the foregoing preliminary account it will have been seen that
the rate of growth and the period of the life-cycle in marine invertebrates
are in many cases much more rapid than has hitherto been suspected.
Many forms which have been generally considered annuals with one
breeding period, such as the Sycons and other Porifera, some Polyzoa,
some Ascidians, some Molluscs and some Annelids, have been shown
to pass through two generations, and in many cases there are strong
probabilities that they may pass through more than two genera-
tions ina year. Even among the Hydroids the rate of growth is probably
ereater than has generally been suspected.
The results obtained will be discussed in relation to those obtained
elsewhere, when the whole of the scattered literature on this subject has
been gathered together. So far, however, very few reliable observations
have been found on the rate of growth in marine invertebrates, as indeed
Weismann* has already noticed, and I should be very glad to receive
any references to work of this kind that readers may have come across.
* A. Weismann, Essays upon Heredity, Vol. 1, p. 57. Edited by E. B. Poulton, 8.
Schonland, and A. E. Shipley. Oxford, 1891
General Report on the Larval and Post-Larval
Teleosteans in Plymouth Waters.
By
R. 8S. Clark, M.A., B.Sc.,
Naturalist to the Association, Plymouth Laboratory.
With 11 Figures in the Text.
CONTENTS.
PAGE
INTRODUCTION : x - : ; 5 a ‘. F : : a BRET)
CHART ; : : : : : : : : facing page 329
Taste I. List or Stations ; B mer4)
List or Faminiss REPRESENTED—
Clupeidee < : : 5 3 5 : : : : - 338
Syngnathide : F < : : : < é : - . 340
Ammodytide : . : c : : . - . : . 340
Gadidze - x : ; : 3 ‘ : : : : . 340
Mullidee : . ; F : : ‘ ; : ; : 5 Bele
Labride : : é 5 : : : ‘ ‘ ‘ aoa
Carangide . 3 : ; é : 5 2 : : . 348
Scombride . ; : : 5 7 3 3 ‘ , oso
Zeid : : j ; ; ‘ ‘ , E : F 5 Bah!)
Caproide . ; ; : A : : ; : : : . 353
Pleuronectide : : : F F F : 3 , : 5 She
Gobiide 3 2 : ; 5 3 ‘ é ‘ Soe
Cottidee : , ‘ ‘ : j : : : 5. ale
Cyclopteride 5 é - : : - : : : : . 376
Triglidz : i 3 C 5 . - : 5 . - 376
Trachinide : : A A 5 : : F Z A ae ele
Callionymidez : : : : : 5 : : - : . 318
Gobiesocidee 3 : : - : : 3 ‘ F 7 ols
Blenniidze F i : 5 r : C 4 3 A yoke)
TABLE XXV. GENERAL TABLE. . 5 A : : é : . 380
ConcLUDING REMARKS ‘ A F : ‘ : : é : + 392
LITERATURE é : F : : 5 : 6 5 c : - 392
INTRODUCTION.
THE material on which the present report is based was collected by the
Oithona from 1906 to 1909 inclusive, and during the latter half of 1913.
Attention was directed particularly to the capture and determination
of the post-larval fishes. The investigations during the first four years
were carried out by Mr. A. HE. Hefford, and his notes have been fully
relied upon for the identification of the species. For the collecting and
working out of the 1913 material I am directly and wholly responsible.
328 R. S. CLARK.
The young-fish trawl was used throughout for the capture of the
specimens, and hauls were taken at depths ranging from the surface to
the bottom. This method of securing the young pelagic stages has
proved so successful in the Danish researches that it has been followed
at Plymouth, with equally good results.
All the nets used were constructed on the system of the Petersen
young-fish trawl, and three qualities of material were used. These were
coarse sacking (“‘Stramin’’), with mesh 75” square ; cheesecloth, with
mesh 3,” square; and mosquito netting. In order to withstand the
strain of pulling on board, the last type was strengthened by an outer
herring-net. It was noticeable that every sample taken with the first
two types contained a mass of stringy substance, indicating considerable
wear and tear of the net. As a result, these nets became weakened and
quickly broken up, especially near the cod end.
Table 1 gives a record of the number of hauls with the locality, date,
and depth at which these were taken. To distinguish between the hauls
taken by Mr. Hefford and those by myself, I have used the letters H and
A respectively, which appear after the number of the haul. Letters
corresponding to the chart areas are also represented.
Tables 2-24 contain records of the number and size of the individuals
of each species investigated, and these are usually accompanied by short
notes on the more important biological features of the particular groups,
but it has been necessary to give a detailed description of a few forms
which appear to be either entirely new, or at most, little known.
Table 25 summarizes the captures of the species the individuals of
which were too numerous for separate tabulation.
The region investigated and shown on the accompanying chart has
been subdivided into areas with latitude of 5’ and longitude of 10’. An
approximation to the positions of the hauls can thus be arrived at by
reference to Table 1. Small crossed circles have been used to indicate
the position of the hauls for the years 1906-1909 and plain circles for 1913.
The credit of the work for the results from 1906-1909 must be given
to Mr. A. E. Hefford, while I have received much helpful advice from
Dr. Allen, Mr. C. Tate Regan, Dr. Kyle and Mr. E. T. Browne. In the
preparation of this report I have had the assistance of my colleague
Mr. E. Ford, to whom I am also greatly indebted for the excellent series
of drawings which are reproduced in the text and for the lettering in
the chart. Further, Mr. Gossen has been a valuable help in the collect-
ing and sorting out of the material.
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CLUPEIDA.
The Clupeoids, which are recorded in Table XXV, have not been fully
determined specifically, though the material contains examples of three
species, Clupea harengus L., C. sprattus L. and C. pilchardus Walb. A
survey of Table 2 shows a maximum frequency in numbers during May
and June, and the records for these two months are chiefly those of the
Sprat, though Herring and Pilchard are also represented. The increase
in numbers during September and October, after a decrease in July and
August, was due largely to the capture of larval Pilchards, which were
easily identified by the presence of an oil globule and segmented yolk.
The occurrence of the eggs and early stages of C. pilchardus during a
considerable part of the year raises the important question (which will be
discussed in a later contribution) as to the periods of spawning for this
species.
SYNGNATHIDA.
TABLE Sui
RECORD OF NUMBER AND SIZE OF INDIVIDUALS.
No. of S. acus, S. rostellatus. N. equoreus,
Haul. Date. Depth. No. Sizemm. No. Size mm. No. Sizemm.
IAW Jal 22.v.06 B. 3 13-15 —_ — — —
OW LL 28.vi.06 M. — — 1 1'7/ — _
XO Isl 11.ix.06 18% _ _— 4 24-65 —_ —
DOD, lal 4.x.06 183 _ — 1 ° 27 —_ _
IDPs WANTS IEE 19.vi.08 B. 1 IP} — — = a
LXXVII. 2.vil.08 B. 1 19 — — _ —
UPON aL 15.vii.08 B. 1 22 “= — a —
MCIV. Hi 26.vili.08 M. 2, 23 — _— — —
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(OPO. WANG IaL 19.vii.09 Ss. _ _ 1 23 — --
EX VA 16.vi.13 B. — — 1 20 — _
XLI. A 28.vil.13 M. — — 1 14:5 — ~-
XLIT. A af M. — — 1 25:5 - —
XT TE AY 45 Ss. _ — i 26 ~ _
XLIV. A 29.vii.13 — _— — — _— 1 9
XLVI. A xe M. — — 1 14 —_ -—
XLVIII. A 30.vii.13 B. _— _ 2 21—29-5 — —
Ibo AN 2.vill.13 Ss. 1 56 — — _ _
LXXXI. A 19.viii.13 B. _ — 1 33 — —
LPO; O,OWIN IS AN 22. vii.13 M. — _ 3 17-20 —_ _
LXXXIX. A % Bs _— — 4 17-5-22-5 — -
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CENT eA: 8.ix.13 B. 1 21 — = — _
C XX. A An EB. — — _ — il 22
CLX. A PPA e113} B. — — 1 36:5 — —
CLXV. A 24.ix.13 B. — —- 3 16—42 oa —
CLXXXIV. A Hess 1153 18} _ — il 14 _ —
CLXXXIX. A 14.x.13 B. _ _— —_— —— 1 11
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340 R. S. CLARK.
SYNGNATHIDA.
Syngnathus acus L. SS. rostellatus Nilss. Nerophis cequoreus L.
Larval and post-larval pipe-fishes occurred sparingly in the young-
fish trawl material. They represent types of three species, of which the
commonest is Syngnathus rostellatus Nilss. Most of the specimens were
taken in bottom hauls close inshore, with a higher frequency from the
mouth of the Sound inwards. A few were taken offshore, notably two older
stages of S. acus, in surface hauls at midnight from 3 to 5 miles south of
the Eddystone rocks.
AMMODYTID.
Ammodytes sp.
According to the records in Table 25, the frequency of the sand-eel
larve and post-larve is greatest between the thirty and forty fathom
lines, decreases slightly between the twenty and thirty, and is practically
limited to a few records under twenty fathoms.
The summary (Table 4) shows a gradual increase in numbers until
August, and a decrease in September, after which no individuals were cap-
tured. There is thus a comparatively dense spawning period in the middle
months of the year, which seems to correspond to the period assigned
to A. lanceolatus. Ehrenbaum considers the lesser sand-eel (A. tobvanus)
an earlier spawner. The period of maximum hatching for this species
in the North Sea lies between January and March.
Both species are represented in the collection, but I have been unable
to separate out the two forms as they show no obvious specific characters
which would ensure accuracy in identification.
GADID.
Gadus pollachius L. G. merlangus L. G. minutus O. F. Miiller.
G. luscus L.
These four species of Gadoids have been brought together in Table 5.
It will be seen that the maximum number of individuals lies in May and
June, and that these are mostly whiting (@. merlangus). The pollack is
an early spawner, but this may not account altogether for the scarcity
of post-larval forms, especially when one considers the tolerable abun-
dance of older stages in the littoral areas in summer. The records
of G. minutus and G. luscus are important, and may help to throw
some light on the spawning periods of these two closely allied species.
G. luscus larvee were taken in September, October, and November, 1913.
Investigations were carried on at intervals during December of the
same year, and during January and February, 1914, and eggs of this
341
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species were still abundant in the tow-nets, while larvee were occasionally
taken. Ova of G. minutus were not observed during this period, but it is
possible that they may have been represented in the later February
catches. There is evidence from the table that the bib spawns in
February, March, and April, if not later.
In the four species of Gadus, frequency is high for the early pelagic
stages beyond the twenty-fathom line, but gradually diminishes in
intensity in the same area as the individuals get older.
TABLE V.
RECORD OF GADUS SP.
No. of G. pollachius. G. merlangus. G. luscas, G. minutus,
Haul, Date. Depth. No. Size. No. Size. No. Size. No. Size.
ii 2 2av206 Ss. 2 5-10 11 5-17 — = — =
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Vi El S30 v206 1By i 7:5 29 4-9 — — 26 4-9
VII. H 5 Ss = = 5 7:5-10 — — — —
WANT, “1eE 3 B. — a 1 9 _ — — =
ID B. — _ ? 8-13 — _ 3 17-18
EX El a B. — = ep de — _ — _
LXXTII. H 25.vi08 B. — — 2 11-14 — _ _ —
LXXIV. H _ 30.vi.08 Bs, = _ 6 5-8 _ — — =
LXXV. H 53 B. — _ —_ _ li 4 — —
LXXX. H 15.vii0d9 B. — — 1 15 — _ _ =_
XCV. H 28.iv.08 Ss. = — 4 5-10 — _— — =
XCVI. H “ B. — 6 7-10 1 6 3 15-18
XCVII. H_ 3.v.09 ? oa — ll 5-15 — — — —
XCIX. H_ 13.v.09 M. — _ 20 65-11 — — 14 7-12
Cc. H 24.v.09 Ss. — — 2 885 — _ —_
CE) a B. 1 22 11 75-10 — = = =
Chien 2577109 Ss. = _ 4 6-12 1 u — —
CHI Ei an M. — — ll 6-12 — _ — —
CV Et oF B. 1 23 26 7-13 1 6 1 10
CV. H_ 10.vi.09 8. 1 28 2 9-13 — _ _ —
CVI. Ei 95 B. 13 23-42 5 65-14 — _ _ -
CVIII. H 22.vi.09 B. — _ 4 8-12 — _ = —_
GEXA 26:vit09") is: 4 22 14 8-15 — _ — _
CX. 35 B. _ 3 1-75 = — — _
CXIII. H 29.vi.09 Ba = = 4 75-8 — _ 3 8-13-5
CXV. H 6.vii.09 Bee 31 6 — _ — _ _ —
CXVI. H _ 8.vii.09 ? — = _ — _ 1 54
CXVIII. H 13.vi.09 M. — _ _ _ — — ] 49
CXXI. H 20vii09 M. — _ 1 9 _ =— 1 26
CXXII. H a B. — — 1] 12:5 — — = —
CXXIV. H 6.viii.d9 M. — _ 1 62 _ — —- —
I. A 6.vi.13 Ss. = _ 2 5:-6-7:5 — = = =
THOE, vai 6 B. — — _ — _ _ 5-7
V. A 12.vi.13 M. — - 1 805 — — _ _
VI. A 18.vi.13 M. — — 29 6-10 — = = =
VII. A - Ss — 3 7-10-4 — — — _
VIIl. A = M. — — 62 7-12-25 — = — =
IX. A A B. — -- 25 7-3-14 — _ — _
Xa AS IG viele) BS — _ 5 7-10.8 — = = =
xe VAS USiviels Ss —_ 2 8-82 — _ — _
2OOU i AN 3 M. — —_ — _ — _— O69
XTV. A op B. — — 3 95-12 — — — _—
XVI. A 19.vi.13 M. — — 1 12:39 — == = =
XOX AS 20! visls Ss = ~ 1 7 — _ — —
XXI. A 24.vi.13 Ss. = _— 6 7-12:6 — — _ =
XXII. A 27.vi.13 M. — — 3 6:9-9:5 — - —_ —_
OSV AN on Vile B. — — 1 10 _ — _ _
XXXIX. A 25.vii.l3 S..o — — 3 27-52:5 — —_ _
XLIT. A 28.viil3 M. — — 1 50 — ~ — —
CXXIIT. A 8.ix.13 M. — -- — _ 1 8 — _
CLVII. A 22.ix.13 B. — _ = = 1 8 _ —
CLXXI. A 26.ix.13 M. — — _ - 1 623 — —
CLXXVI. A a B. — _ _ _ 1 5:76 — —
CLXXVIII. A 29.ix.13 M. — — _ — 1 + — -
CLXXXVIII. A 18.x.13 B. — — _ — 1 469 — _
CLXXXIX. A 14.x.13 B. — — — — 1 335 — _
CXCII. A 24.x.13 M. — _ — — 2 449 — _
CXCIV. A a M. — - _ _ 1 489 — _
CCV. A 26.x113 M. — _ _ —_ 1 3.4 — -
344 R, S.) CLARK:
GADIDA.
Molva molva UL.
Twenty post-larvee of the common ling were taken in May and June.
These ranged from 5 mm. to 13:09 mm. With the exception of five
specimens taken in Cawsand Bay, all occurred beyond the twenty-
fathom contour line, and the majority of these between twenty and
thirty fathoms, at no great distance from the shore, and off the entrance
to the Sound. All the stages are similar to those described and figured
by Schmidt in ‘‘ Medd. fra Komm. for Havund. Serie Fiskeri,”’
Bind II, 1906.
These records suggest a similar, though perhaps less extended, spawn-
ing period to that for the North Sea, which Ehrenbaum gives as March
to May, with a maximum in April.
TABLE VI.
Recorp or Morva motva L.
No. of Haul. Date. Depth. No. Size.
1%, 181 22.v.06 B. 1 5
\Wie1sl a B. i 9
XVII. H 28.vi.06 B. 2 10-15
> UAB HIS aE 28.v.08 M. 3 ?
Ibi 18! 5.vi.08 Ss. 1 7:5
IDM, dal = iB: 1 tf
Ibe, le! 12.vi.08 iB: 1 8
IDDSIE, 18! 15.vi.08 B. 2 ?
LP Oe ice 19.vi.08 M. 1 9-5
IDOI, IRE 30.vi.08 Be 1 5
DPXOaVe Ee 30.vi.09 B. 1 8
(CIH0R Isl 2.vi.09 M. 1 13
lie cA: 11.vi.13 M. 1 6
GV At 19.vi.13 M. 2 8-75-10-7
XOX UA PAT plat ls) M. 1 13-09
GADID.
Raniceps raninus lL.
The records of the lesser forkbeard are confined to 8 specimens ob-
tained from 13th August to 8th September, 1913. A spawning period
from July to August is thus indicated. For the North Sea, Ehrenbaum*
has given from middle of June to middle of August.
All were taken between the twenty and forty fathom contour lines.
The occurrence of these early stages is interesting, when it is considered
that the adult forkbeard is distinctly rare in the neighbourhood. Two
* Nordisches Plankton. Vol. II. Eier und Larven von Fischen. 1905.
LARVAL AND POST-LARVAL TELEOSTEANS. 345
early post-larve of 4-5 mm. bridge the gap between Ehrenbaum’s 3 mm.
larva and Schmidt’s* 5 mm. early post-larva. The general outline of the
fish (with the rounded profile of the head) resembles Schmidt’s 5 mm.
specimen very closely. Pigment is slightly more pronounced, especially
over the abdominal surface, where large stellate chromatophores oi a
rusty-brown colour are more closely packed on the dorsal part of this
region. Chromatophores also appear on the suborbital region.
TABLE VII.
RECORD oF RANICEPS RANINUS L
No. of Haul. Date. Depth. No. Size.
LXXIV. A 13.vi1.13 M. 3 4-5-9
LXXIX. A 18.vii.13 B. 1 17
XCV. A 25.viii.13 M. 1 iby)
Chi A 27.vi.13 M. it 18-5
CxO A 8.ix.13 B. 1 4:5
CXXVII. A 9.ix.13 M. ] 5°5
GADIDA.
Onos mustela L. O. tricirratus Bl. O. cimbrius L.
I can only identify with certainty one post-larva 3-75 mm. in length
as O. cimbrius. It was secured at the surface in haul 58 A, on 2nd August,
1913, 6 miles 8.8.W. of the Eddystone rocks. It has the single typical
post-anal bar and the long black ventrals as described by Ehrenbaum,f
and lies between his Fig. f and Fig. g. Only two adult specimens have
come under my notice. One, 22-5 cm., was taken in a commercial
beam-trawl on the outer Eddystone Grounds in November, 1912;
the other, 15 cm., in a mosquito-net attached to the shackle of the
otter-board, 34 miles W.S.W. of Rame Head on 2nd September, 1913.
These have the first ray of the first dorsal fin extremely elongated.
Early post-larve of O. tricirratus were not observed, and only the
later stages, with the three barbels developed, could be identified with
accuracy.
O. mustela occurred from March to September with an intensity in
June. The characters of these young stages are by no means obvious,
and it is just possible that a few may belong really to O. tricirratus. The
real difficulty in identifying the rocklings at Plymouth will be overcome
when the early stages of O. tricirratus are worked out more fully.
* Medd. fra Komm. for Havund. Serie Fiskeri. Bind. II, Nr. 8. 1907.
+ Nord. Plank. Vol. II, p. 280.
346
No. of Haul.
Ve
XLVI.
LXXIV.
LXXXII.
CV.
CXVI.
CXVIII.
CXXII.
XXXIX.
LI.
LVII.
LXIII.
LXIV.
LXXVIII.
CXXIX.
Records of post-larval red mullet were extremely few,
Prrrrrr rrr rrr PPro t tee eee eee eee eee
R. 8. CLARK.
TABLE VIII.
REcoRD OF ONOs Sp.
Date.
22.v.06
20.vi.06
39
28.vi.06
20.vii.06
11.iv.07
10.vil.07
1.vi.08
2”
5.vi.08
10.vi.08
12.vi.08
30.vi.08
20.vil.08
10.vi.09
8.vul.09
13.vii.09
20.vil.09
11.vi.13
18.vi.13
19.vi.13
20.vi.13
30.vi.13
7.vu.13
15.vii.13
25.vii.13
1L.vii.13
2.vill. 13
7.vi.13
11.vii.13
18.viil.13
9.ix.13
MULLIDA.
Depth,
AWS ESLNANNRE SH EN~ SNE HMMM MH Siem by
O. mustela,
Size.
5
4
10
A
°
il (ea |p ener may ret eran fen ono Rau ssclE APS i nC papas
iB
co
oo Or Ge
hones
fs
| [Pap esicany
AH Ko
ot
Co
ns
ee Scel
= \-
bo oO
ae
o |
©
oo |
Mullus surmuletus lL.
to June, July, and August.
this species.
seem to be clearly diminishing in the neighbourhood.
O. tricirratus,
No. Size.
1 30
1 32
1 19
1 PAS
a 36-5
2 25-25.5
2 17-23
1 28
1 37:5
This indicates a spawning period from
May to July, which corresponds to the known period of spawning for
There is unequal representation during the five years,
but, owing to the scarcity of young forms recorded, no actual deduction
can be made as to the yearly fluctuations of the adults. Their numbers
and confined
LARVAL AND POST-LARVAL TELEOSTEANS. 047
TABLE IX.
Recorp or MuLLUS SURMULETUS L.
No. of Haul. Date. Depth. No. Size
xSVil CE 28.vi.06 B. 2 5-6:5
EX EX, GED 20.vil.06 2 1 6
XEX Et os z 2 5-5:5
xO EE 27.v1i.06 ? ll 4-5-5-5
XOX EE oA ? 2 5-5-7
Cx. Ei 29.v1.09 B. 2 7
CXVII. H 13.vii.09 S. 1 7
OXEX= EE 20.vil.09 8. 5 5-6
Cx, Hi 5 ? 6 5-5-7-5
CXXII. H = ? 4 6-7-7
CXXIV. H 6.vili.09 M. 4 4-5-6:5
@XEXV5 SE AA B. 3 5-6
LVIl. A 2.vili.13 M. 2 4-69
LABRID A.
Labrus bergylta Asc. Ctenolabrus rupestris L.
I have referred the pelagic young stages to the above two species
which are recorded in Table 25. Ctenolabrus rupestris L. is quite a
distinct form and easily recognized by the help of Ehrenbaum’s descrip-
tions and figures in “ Nordisches Plankton,” Vol. I. Holt gives the
spawning period from April to July, and this agrees with the occurrence
of the species during the present investigations. The maximum frequency
is in July ; distribution is general in the area investigated.
The records of L. bergylta Asc. show a similar spawning period with
an extension to August. The maximum is in June and July. It is
possible that a few individuals of L. mzxtus may be included in the list,
but as the present state of our knowledge with regard to these two
forms is extremely limited, the latter has meantime been excluded.
The material seems to suggest two forms, one with a clear caudal peduncle
region, the other with a slight continuation of the black stellate chromato-
phores along the ventral margin as indicated in Hefford’s newly hatched
larva of L. mixtus.* These two forms, however, show gradations of
pigment.
* Journ. M.B.A. N.S., Vol. IX, No. 1. 1916.
348 RAS GLARE
CARANGID A.
Caranz trachurus L.
TA BER Xe
REcORD OF CARANX TRACHURUS L.
No. of Haul. Date. Depth. No. Size.
xXXV. H 10.ix.06 B. 1 13
1PPOMIDS, 181 30.vii.08 Ss. i ean 27
OXGVA eo 13.vii.08 M. > ea. 4
CXXI. H 20.vii.09 M. 2 4-5-5:5
CXEXDVE Ef 6.vili.09 M. i cans
CXXV. +, Bs 1 6
CXXX. H 26.viii.09 B. il 7:7
DXOXOXGIEXG A’ 25.vii.13 Ss. 1 5-95
DAE AWALS YAN 29.vii.13 M. 1 16:5
LVI. A 2.viii.13 M 1 10
Vitti. A 5 S. 1 16-5
LX. A 7.vili. 13 8. 1 18-5
LXIV. A 1l.viii.13 M. 1 4-489
LXXIX. A 18. viii. 13 B. 1 5:36
TEXOXeXOVil a At 21.viui.13 M. 1 48
XCV. A 25.viii. 13 M. 3 5-6
XIGViEE A: os 1B4. 1 6.
XOVilhine eA Es M. 1 4:5
MCLX. A 26.viii.13 M. 2 5-5-6°5
Cu vA 27.viii.13 M. 1 5-226
rOUITE - vAk A M. il 6
CVF eA 29.viii.13 M. 6 19-26-5
CVai, 2A: HN eiexes Uhey M. if —
CVIII. A Bs M. 1 4
(ODOWANE AN DEX lle M. 50 ca. 63
@XOXCHIS AT 8.ix.13 M. 3 27-33
CXXIX. A 9.ix.13 Ss. 1 73
CXXXII. A Ileror< 118? B. 1 80
CXEEXV. A 12.ix.13 M. 1 50
CXSEXVA, A: o M. 2 46-65
Cxeieie VA: V5srx. 3 B. 2 66-75
CLVE, A 20.ix.13 M. 1 4-5
CLXXi. A 26.ix.13 M. sb 16
CLXXTT, A 26.ix.13 M. 1 8
CLXXIV. A a3 Bs 1 9-5
CLXXXII. A 30.ix.13. M. il 6°5
Caranz trachurus L.
The spawning period of the scad has been given as May and June for
the English Channel, but an extension at least to August is warranted by
the present records, which indicate June to August. The frequency
increases from the twenty-fathom contour line outwards. Young stages
with fully developed adult characters were taken in September, generally
in midwater or quite close to the surface, at lengths varying from 50 to
80 mm. Several individuals from haul 117 between 60 and 70 mm. in
leneth were kept alive on board the Ozthona, and transferred to the
aquarium tanks. They fed ravenously on small pieces of worms and
squid. Measured on 9th February, 1914, six months exactly after
transference to the aquarium tanks, they gave measurements ranging
from 105 to 130 mm. They had thus almost doubled their length in
half a year. Their age may be taken as 9 months, if June be considered
the spawning month.
LARVAL AND POST-LARVAL TELEOSTEANS. 349
SCOMBRID A.
Scomber scomber L.
Post-larval mackerel were exceedingly few. One hundred and eighteen
specimens from 4 to 13 mm. in length were taken during the period of in-
vestigation. These occurred during June and July, so that spawning in
the neighbourhood must have begun in May in each year. The frequency
in numbers is seen to decrease inshore, and to increase from the twenty-
fathom line outwards. Previous captures of the same stages (and these are
by no means numerous) have been recorded chiefly at considerabledistances
from land. It is thus highly probable, from the scarcity of individuals
in the samples, that the early stages occur in greater numbers much
farther out than the area investigated. Subsequent stages have been
observed at Plymouth at lengths of about 100 mm. One specimen of
200 mm. was caught in a commercial beam-trawl west of the Eddystone
rocks on llth February, 1914. Scales were developed, which were
obviously in their first year’s growth, but on considering the length of
the fish, the age must be about 1 year 9 months, if, according to Ehren-
baum, scales begin to develop during the second year.
TABLE XI.
RECORD OF SCOMBER SCOMBER L.
No. of Haul. Date. Depth. No. Size.
Det dL 20.v1i.06 M. 7 §:5-7:3
>is del ie 18%, 1 6
SBE, JEL 5 Ss. 2 f=1:5
GOH dsl RB: M. 4 6-7-5
XeRVigu El a B. Acai
Wis IL 28.v1.06 S. 6 7-11
DOWai Vel 28.v1.06 M. 3 7-7-7
MOWAT, Lee ms B. 14 7-10-5
XCIEXG, SET! 20.vii.06 Ss. 1 7
EXeXG SE: 27.vii.06 ? 2 47:3
ORs Jal aS ? 3 411.
IEMs aE 10.vi.08 Ss. 1 7:5
ILID<. al 12.vi.08 Ss. 6 6-8
aXe EE e B. 1 6
Ibpaig asf 15.vi.08 B. 2 7-7-6
LXIII. H 19.vi.08 B. 1 7
i xenVe El ss Ss. 4 7-5-10
EV. “EL Ls M. a 8-9
LXVI. - B. Zee Cann,
IDI BL 23.vi.08 Ss. 2, 8-9
LXX. H = M. 13 4-5-12
Exe. “Ei Pe B. 9 7-10
Clan Er 29.vi.09 S. 3 9-5-11.5
CXVil.” 13.vii.09 Ss. 1 ca. 7
CXS 20.vi1.09 Ss. 8 7-9
CXORE TH: Bp ? 3 6-5-7-5
(OO, Gig Wal 35 ? 3 6:5-10
ene (A: Ie sail 18} M. 2 4-9-5-04
DEVE A: 19.vi.13 M. iL 11-5
XXXIV. A 16.vii.13 M. 1 13
XXXIX. A 25.vi1.13 S. 1 9-45
350 R. S. CLARK,
ZEID AL.
TABLE XII.
REcORD OF ZEUS FABER L.
No. of Size in
No. of Haul. Date. Depth. Spec. mm.
LUI. A L.vili.13 S. 1 7:5
OUI A 25.viu.13 M. 1 5:5
CoA 27.viil.13 M. 2 9-11:5
(Oil Ak = M. 2 11-5-13-5
CII. A x M. 1 8
Clas eA 29.vill.13 M. 1 16
CLV; VA a 1B}. 1 6
CVIIl. A textes M. 2 8-19
CXI. A Byars 13} M. 1 6
CXIII. A 33 S. 1 15:5
CXVIII. A sya bse 13} M. 1 4:5
CXXV. A 9ix.13 M. 1 23
CXXXI. A 1lix.13 M. 2 11-5-13
CXXXII. A a 13% 1 11-5
CXXXV. A 2 Riel} M. 1 17:5
CLXXVI. A 26.1x.13 B. 1 a
Zeus faber L.
Our knowledge of the early post-larval stages of the John Dory seems
to be restricted to the excellent descriptions of Schmidt in “ Medd.
fra Komm. for Havund. Serie Fiskeri,” Bind II, No. 9, 1908. These
post-larvee ranged from 7? mm. to 19 mm. in length, and were taken in
the English Channel “ almost all within the 100-metre curve” from the
end of August to the middle of September. My own observations con-
firm and supplement those of the Thor. The series which I have
recorded ranges from 4:5 to 23 mm., and all were captured within the
twenty and forty fathom contour lines, from the beginning of August
to the end of September. Six of these from 4-5 to 7-5 mm. represent
younger stages than Schmidt’s earliest post-larva of 73 mm., and I have
described and figured two of these, one of 4-5mm.andoneof6mm. The
remaining fourteen, from 8 to 23 mm.,agree in every respect so closely with
Schmidt’s series that nothing by way of description need be added here.
Fic. 1. Lreneru 4°5 mm,
The maximum height is 2-04 mm., and the length from snout to
caudal fin 3:06 mm. The highest point of the body lies directly over
the posterior margin of the orbit, and in front of the first dorsal fin. The
resemblance in shape to a parallelogram noted by Schmidt for his
72 mm. post-larva is roughly defined. The angle of the snout is very
nearly 90°. The contour of the eye is not quite complete, but, so far
as can be judged, its diameter is about equal to the length of the snout.
The notochord is straight and extends about $ along the caudal fin,
whose rays are only partially developed. The unpaired fins are still
LARVAL AND POST-LARVAL TELEOSTEANS. 351
joined to the caudal by a continuance of their fin membranes. The rays
of the first dorsal are indistinctly marked. Dorsal and anal interspines
are clearly developed, but the fin rays are merely indicated. The
ventrals are six-rayed, third largest and sixth shortest. They reach to
the middle of the anal fin.
Fie. 1.—Zeus faber, Length 4°5 mm. Oithona Station, CXVIII. A. 5th Sept.,
1913. Total depth 37 fms, Midwater haul.
Del. E. Ford.
The whole surface of the body is covered with large black stellate
chromatophores on a greenish background. These are intermingled
with smaller chromatophores. The head is not so densely pigmented,
and the interspaces between the chromatophores are larger. The ventral
fins are densely pigmented with numerous large closely set chromato-
phores, giving the fins almost a black appearance. The pigment on the
first dorsal fin is also evenly distributed, at least on the anterior half.
No pigment occurs on the second dorsal, anal, and caudal fins.
Fic. 2. LENGTH 6 mm.
The maximum height is 3-004 mm. and the distance to the caudal
4:78 mm. (to end of body pigment). The highest point of the body is
just in front of the first dorsal fin. The angle of the snout is slightly
obtuse, and its length about equal to the diameter of the eye, the contour
of which is still incompletely defined. The notochord is still straight or
perhaps with a very slight upward tendency, caused by the hypural
rays of the caudal being more developed. The unpaired fins are now
separated from the caudal-fin membrane, and their rays are clearly,
though not fully, defined.
The body pigment has spread on to the base of the dorsal and anal
B02 Ri 8.°CLARK.
interspinous regions. Over the whole surface of the body there is a
mixture of large and small stellate chromatophores, and smaller black
dots. The unpaired fins are still unpigmented. The anterior half of
the first dorsal fin has an aggregate of black chromatophores. The snout
region has the least amount of pigment.
The spawning of the dory, according to Cunningham,* takes place
during June and July. Hefford} obtained ripe ovarian eggs on 31st
August, while Holt{ observed spent dories in June off the west coast of
Fie. 2.—Zeus faber. Length 6mm. Oithona Station, CXI. A. 3rd Sept., 1913. Total
depth 32 fms. Midwater haul.
Del. E, Ford.
Ireland. The post-larve recorded in the above table suggest a spawning
period extending from July to the beginning of September, though it
is probable from previous records that spawning may also occur in June.
Cunningham* worked out the rate of growth of the dory, and gave
lengths of about 130 mm. at the end of the first year, and about 280 mm. at
the end of two years. The usual length of the dory landed at the Plymouth
Barbican is from 15 to 18 inches, which, as Cunningham remarks, “ is
probably not reached in less than three years.” On examining the rings
of growth on the opercular and hyomandibular bones (especially on the
cerato-hyal), according to Heincke’s method,§ I find the results agree
with those of Cunningham, though not many specimens were examined.
The material was secured by the Ozthona in the Agassiz and otter trawls.
O Group. I Group. II Group.
<150mm. .. ca.150-ca.250mm. .. ca. 250-ca. 300 mm.
* Jour. M.B.A. N.S:, 25 1891-2: + Journ. M.B.A. N.S., 9. 1910.
t Rep. Roy. Dublin Soc. 1892. § Intern. Meeres. Jahresbericht, 4-5.
LARVAL AND POST-LARVAL TELEOSTEANS, 353
CAPROID.
TABLE XIII.
REcORD OF CAPROS APER L.
No.of Size in
No. of Haul. Date. Depth. Spec. mm.
XCIII. A 25.vili.13 M. 1 5:5
XCVI. A a B. ihe ep 7c
XCVIII. A - M. 1 37
< XCIX. A 26.vill.13 M. 1 4-69
CXsVi. A 5.ix. 13 M. 2 3-4-4
CXXIII. A 8.1x.13 M. 1 3:5
CLII. A M@) ese 113} M. 3 3:3-5:5
CLXXIV. A 26.ix.13 B. 1 6
Capros aper L.
The capture of eleven specimens, 3-3 to 6 mm. in length, of the Cuckoo
(as it is known locally in the adult state) between the twenty and forty
fathom contour lines within a short radius of the Eddystone rocks, from
Fic, 3.—Capros aper. Length ca.4 mm. Oithona Station, CXVILI. A. 5th Sept., 1913,
Total depth 37 fms. Midwater haul.
Del. E. Ford.
the end of August to the end of September, helps to add considerably
to our knowledge of the early developmental stages of this species. So
far as | am aware, only the eggs and resulting larvee are known through
the researches of Cunningham* and Holt,f and one post-larva 15} mm.
in length described by Schmidt.t Thus, between Holt’s 2-86 mm.
larva and Schmidt’s 154mm. post-larva nothing is known. My speci-
mens are all early post-larve, but, unfortunately, they are too badly
damaged to give a complete descriptive series. However, I have described
and figured one of 4mm.and one of ca.5 mm. Zeus faber, the most
nearly allied form, differs so markedly in its post-larval characteristics
that there can be no confusing its early stages with those of C. aper.
* Journ. M.B.A. N.S., Vol. I. 1889-90.
+ Annales du Musée d’Histoire Nat. de Marseille, Tome V, 2.
t Medd. fra Komm. for Havund. Serie Fisk., Bind II.
354 Rows: (CLARK:
In the latter species, orange-red pigment is already developed in specimens
of 4 mm. (on the abdominal region), while a distinct structural feature
of Capros post-larve is the large number of small spines which cover
practically the whole surface of the fish, and appear more markedly
round the marginal outline. Two specimens were cleared and mounted.
Each had about 22 vertebre.
Fig. 3. LEenecta 4 mm.
The maximum height, measured along a vertical just in front of the
first dorsal and anal fins, is 1-7 mm., and the distance from tip of snout to
Wayne
Fic. 4.—Capros aper. Length 6mm. Oithona Station, CLII. A. 19th Sept., 1913.
Total depth 29 fms. Midwater haul.
Del. E. Ford.
base of caudal fin is 3-2 mm. The longitudinal axis runs through the
middle of the eye. The angle of the snout is very nearly 90°—if anything
less: its length is about equal to the longitudinal diameter of the eye,
the contour of which is still incomplete. The rhomboidal form of the
fish is well marked. Small tooth-like spines are prominent on the snout,
chin, and profile of the head. The second dorsal and anal fin rays are
just beginning. Hypurals are developed on the caudal. The first dorsal
has the spiny rays moderately developed. As yet. the dorsal and anal
fins are both joined by a membrane to the caudal. The notochord is
straight. Dorsal and anal interspines are developed. The ventral fins
are well developed, and reach back almost to the beginning of the anal-
fin region. Number of vertebre_ca. 22.
LARVAL AND POST-LARVAL TELEOSTEANS. 355
Orange-red pigment, over which occur splashes of bright red, is
present on the anterior dorsal half of the abdominal region, while
yellow pigment occurs on the rest of the body and very faintly
in small patches on the head. A dense ageregate of dark pigment
marks off the posterior margin of the abdominal region, beginning
Just above the longitudinal axis and extending as a line of dark
chromatophores to the origin of the anal fin. Large brownish-
black stellate chromatophores are spread over the dorsal half of the
head and body, leaving a clear space in front of the base of the
caudal fin. These large chromatophores are continued across the body
post-anally, along the lower part of the abdomen and the ventral margin
to the tip of the snout. A few black dots are scattered over the red
pigment of the abdominal region. The orbital region, especially the sub-
orbital, is practically devoid of pigment. No pigment is visible on the
second dorsal, caudal, and anal fins, while a few dark chromatophores
appear on the first dorsal and ventral fins.
Fic. 4. LeneTu 6 mm.
The maximum height is contained a little more than twice in the total
length : length to caudal fin about 14 times. The snout is slightly con-
cave above and below as in the adult ; its length is about equal to the
diameter of the eye. The marginal row of spines in front of the first
dorsal fin is very ‘prominent. Similar rows are present on the pre-
maxillary region and along the spiny ray of the ventral fin. The second
dorsal and anal fins are separated from the caudal. Their rays are not
fully developed posteriorly. The spines of the first dorsal fin are strong
and well developed ; nine can be counted. The tip of the notochord is
turned upwards and the caudal rays well advanced. The dorsal mem-
brane of the caudal is still fairly large.
The general arrangement and colour of the pigment is much the same
as in the previous specimen, though the reddish patch has extended
forward on to the orbital region. The colour is generally redder, owing
to the presence of a larger number of bright red splashes.
PLEURONECTID.
Pleuronectes limanda L. (common dab). P. flesus L. (flounder).
P. microcephalus Donov. (merry-sole).
Records of post-larval P. platessa are absent from the tables, though
the eggs were observed fairly frequently during December, 1913, and
January and February, 1914. They appeared in the tow-nets in the
latter part of December, 1913, and continued to be observed during
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914. Z
356 FR SOCuUARK
January and February of this year, though less frequently in February.
The maximum was in January. The diameters of the eggs varied from
1-809 to 2:07 mm. One newly hatched larva measured about 6-9 mm.
These eggs were nearly all secured in inshore areas in Bigbury Bay and
off the entrance to the Sound in quite shallow water.
Post-larval dabs are distributed generally over the area investigated,
though they occur in greater numbers between the twenty and thirty
fathom lines. The flounder shows a higher frequency in inshore areas,
while post-larvee of the merry-sole increase in intensity with the distance
from land. The maximum frequency for post-larve of the dab les in
May, of the flounder in April and May, and of the merry-sole in June.
A specimen of P. microcephalus of 11 mm. shows no sign of meta-
morphosis, whilst in one of 12°5 mm. metamorphosis has commenced
(cf. Kyle,* p. 48, footnote).
PLEURONECTID.
Sub-fam. Boruinz.
Arnoglossus sp.
An examination of several hundred adult specimens taken in the
Oithona’s otter trawl in 1913 proves conclusively, with the help of
Kyle’s work,* the existence of three main species of the genus Arno-
glossus in the neighbourhood of Plymouth. Kyle relied on four principal
features for his segregation of the species, which he classified as :—
(1) Structural Characters.
(2) Dimensional
(3) Numerical ie
(4) Post-larval Characteristics.
These are sufficiently clear and comprehensive to make the identifica-
tion of the three species at Plymouth comparatively easy. A. laterna
Walb. and A. imperialis Raf. (A. lophotes Giinther) occur most abun-
dantly, while A. thori Kyle is comparatively rare.
The character of the first few dorsal rays, the length of the head,
diameter of eye, and length of ventrals seem quite good enough to
separate the three species already noted.
The larval and post-larval material will be reported on more fully in a.
later communication. There are considerably over a thousand specimens,
which represent nearly all the stages up to the metamorphosed condition.
A survey of Table 25 shows a maximum frequency in August and Septem-
ber, which, with the records for the earlier months, suggests a prolonged
29
* Rept. Danish Ocean. Exped., 1908-10. No. 2 (1913).
LARVAL AND POST-LARVAL TELEOSTEANS. 357
PLEURONECTID.
TABLE XIV.
REcorD or PLEURONECTES SP.
P. limanda. P. flesus. P. microcephalus.
No, of Haul. Date. Depth. No. Size. No. Size. No. Size.
Ey LOr206 B. 3 145-15 — _ — —
TiS Hi 22:v.06 S. _ — 6 7-9 _ —
ii SE 22:v.06 M. 1 10 7 7-9 _ —
EV. Hi) 22.v.06 13}. 6 6-9 16 7-8-5 6 8
V., dl a B. 4 10-12 6 55-9 — —
VIZ EE -30:v.06 B. 26 65-10 — -- — —
Viti 13), — oa 24 8-115 — =
XI. H 20.vi.06 B. J 13-5 — — — —
DG 8 0 ee = | 33 M. 6 6-105 — = _ —
XLVS 3 55 13). — — — ao 3 12-14
XVII. H- 28.vi.06 B. 5 7:5 — -- 1 8-5
XXXII. H 25.11.07 S. _ — 7 3°5-8 1 6
XOXO CIE ED 93 M. — — 1 5 —
2OOIMNG TBE ler (Oe M. 8 6-7 15 4-7 = —_
SXCXOXTTV EEL 5 B. 3 9 20 4-5-9 - _—
EXEXOXGV, EE 65107 13}. -- — — oon 2 6-9
DXOXONG Vail GEL a5 S. _ — _ — 1 10-5
XLII. H 28.v.08 ? i 12 - - = --
eEEVE, iEE or 2 16 75-13 — — 11 9-13
XLVII. H_ 1.vi.08 B. 1 10-4 — — — —
XLIX. H as M. 2 12:5-13 — — _ —
iby Jal mA 183. I 13 _ = B) (ee te:
?LIT. H = 4.vi.08 2 — — 2 8-10 — —
IDAGMI5 Tel 3 8. _ — — — 2 7-5-11
nV. Ei 5 M — — 1 8 _ —
VE Ovi 08 8. _ — = — 1
ID\WAlS isl ap B. 1 13 — _— -— —_—
xe He L2:va08 B. — _ _ — 1 8
EEXGVAE ERS LS va08 B. — _ — — 6 7-16
TXGEX. SEL 2351-08 S. — — -- —_ 1 U
XOX EL 3 Me _— _ — 1 8-7
IXOXaIE EE 3 B. - _ — — 2 7-8
LXXIV. H_ 30.vi.08 B. 1 8 — _ 5 6-8
LXXV. H - B. — — — — 9 5-8
XCV. H 28.iv.09 S. — — 3 7-8 _ —
XCVI. H $3 135. _ — 28 8-9 — —
MOV, HH 357.09 2 — — 2 10 — —
SOWA, Jeb owe 2 — — 4 9-10 = =
MCIXS Ei i3.v.09 M. 12 £8-12 _ — — —
C. H 24.v.09 S. _ _ 1 8 _— _
CIV. H 2.vi.09 B: 3 8-12 _ — — _—
CIX. H 265.vi.09 S. _— — 1 9 _— =
CXVII. H 13.vii.09 S. ~ _ -- _ 1 7
Te eA (65vasl3 S. — — 3 7-9:31 — —
ES AS 5 B. 2 6 — _ 2 6:96—7
Tits yAS | Uievasl3 M. — _ 3 7 g —
V. A 12.vi.13 M. 1 1-59 — — 14 7-5-11
VI. A 13.vi.13 M. — — — ~ 4 7-8-5
IX. A oe B. — — 5 7:4-8:54 — _
XG AS elGevanls M. 4 7-10-15 1 8-75 3 7:-7-9-17
XIII. A 18.vi.13 M. 2 10-5-11:5 — _ — _
XV. A + M. 2 11-06-11-34— _ 1 9-5
XX. A 30.vi.13 B. 1 5:39 — _— 1 6
XXIV. A _ 3.vii.13 M. -- —_ — — 2 9-5-10
XXXVIT. A 24.vii.13 B. = — _ — 1 12-5
XLITI. A 28.vii.13 S. 3 39-42 — — — _—
358 R. S. CLARK.
spawning period for the three species. Kyle has noted an indefinitely
prolonged spawning period for A. thori and for A. laterna, and has sug-
gested a similar period for A. imperialis, although he states that the
main spawning period for this last species lies in spring. The occurrence
of a large number of larval and early post-larval forms of A. impervalis,
in August and September, 1913, appears to confirm the view of an
extended spawning period.
The frequency of the three species is highest off-shore between the
twenty and forty fathom lines, and decidedly low within the twenty-
fathom line—the captures inside this limit being confined to four
specimens, 6 to 16 mm. in length, from hauls 70 A and 73 A.
It is interesting to note the occurrence in the collection of the pale
North Sea and English Channel post-larval form of A. laterna, and the
dark Bay of Biscay form of the same species. These two varieties of
post-larvee have been fully described by Kyle, who has suggested a
higher number of vertebree for the more southern form.
Sub-fam. RHOMBINZE.
Rhombus maximus Will. R. levis Rond.
The few records of these two species indicate an earlier spawning for
the brill. Seven of the eight individuals recorded were taken beyond
the twenty-fathom line. Permanent bottom stages of the turbot were
secured with a push-net in Whitsand Bay on October Ist, 1913. These
measured from 25-38 mm. (1” to 14”) in length, and had fully assumed
the adult condition. On the same date, brill of 130-140 mm. (5” to 53”)
in length were secured in the otter trawl in 3 to 5 fathoms in the same
locality. These were probably a little over a year old.
TABLE XV.
RECORD OF RHOMBUS SP.
R. maximus, R. levis.
No. of Haul. Date. Depth. No. Size. No. Size.
MOO Dee HN 25.vii.13 S. — — 1] 5:25
LXXXI. A 19.viii.13 13}, — _ 1 6:5
CV. A 29.viii.13 M. -- — 1 5-5
CXVIII. A 5.1x.13 M. — — 2 3-5-4-2
CXXXVIII. A 12.ix.13 M. 1 vil — —
Ox eA aerate M. ] 7:3 — —
CXLII. A 151x138 B. 1 7 — —
LARVAL AND POST-LARVAL TELEOSTEANS. 359
Sub-fam. RHOMBINA.
Scophthalmus norvegicus Gthr. S. unimaculatus Bnp.
Zeugopterus punctatus Bl.
Scophthalmus norvegicus Gthr.
This is the commonest topknot of the district. The records of the
pelagic stages in Table 25 indicate an indefinitely prolonged spawning
period from March or April to July. The maximum for the post-larve
lies in June, so that the densest spawning month is most probably May.
Frequency is highest between the twenty and thirty fathom lines, and
lowest beyond the thirty-fathom line.
TABLE XVI.
RECORD OF SCOPHTHALMUS UNIMACULATUS BNP.
No. of Haul, Date, Depth, No. Size.
xs, A! 16.v1.13 B. 1 75
XXIII. A 30.vi.13 Be 1 7:98
XX. A 15.vii.13 B. 1 11
The adult one-spotted topknots are of exceedingly rare occurrence
at Plymouth, so that the capture of these three post-larve is all the
more interesting. They were all secured beyond the twenty-fathom line,
from 16th June to 15th July, and were identified with the help of Peter-
sen’s descriptions and figures of specimens, ranging from 6-7 to 8 mm.
in length.
The oldest stage has a length of 11 mm., and it is still perfectly sym-
metrical. The concavity of the snout is well marked, and the dorsal fin
is almost on a level with the posterior margin of the orbit. The diameter
of the eye is contained about three times in the snout length. Ventrals
are developed, though still small. The caudal fin is rounded and almost
fully developed and about seventeen rays can be counted. The two pairs
of otocyst spines are quite conspicuous, though not so prominent as in
Z. punctatus. .
Small dendritic chromatophores are scattered over the head and body,
much as in S. norvegicus, though practically absent from the orbital
region, and less dense on the interspinous region. There is a suggestion
of the pigment on the unpaired fins beginning to concentrate into bars.
360
R. S. CLARK.
TABLE XVII.
RECORD OF ZEUGOPTERUS PUNCTATUS BLOCH.
No. of Haul Date. Depth. No. Size.
Ve EL 22.v.06 B. 1 6
V. 35 B. 1 7
WARES 412 30.v.06 B. 6 “ca. LL
VE Et 20.v1.06 igs. 1 9
ONCE) EE: 11.iv.07 M. 12 5-6
XXXIV. H - B. 3 3-5
SEXES. 6.v1.07 B. 2 6-9
XLIV. H 18.v.08 B. 2 7-75
EXOVaS” EE 19.vi.08 B. 1 9
XCV. HH 28.iv.09 S. 1 4
Cri 451 2.v1.09 M. 1 7:5
CX. H 10.vi.09 M. 1 9
py Al 6.v1.13 S. 10 6-5-8.5
Ue BAY 11.vi.13 M. PA [ets [play
Wile 5A: 13.vi.13 M. 1 6:3
ens oA! 16.vi.13 B. 1 11-69
XViD 18.vi.13 M. 2 8-8:5
Post-larvee occurred
June.
Zeugopterus punctatus Bl.
from April to June, with their maximum in
The spawning period probably extends from March to May for
the Plymouth area. Hefford gives middle of February to May. Their
distribution is general, though there is a much higher frequency under
ten fathoms and between the twenty and thirty fathom lines.
1
Sub-fam. SOLEINZE.
TABLE XVIII.
RECORD OF SOLEA.
S. vulgaris. 8. variegata. S. lutea. S. lascaris.
No. of Haul. Date. Depth. No. Size. No. Size. No. Size. No. Size.
mm. nm mm, mm.
Ts Et 10.v.06 Bs 1 10-5 — — — — — _
IV. H 22.v.06 B. 2 4 72 6 —_ — — —
VAS SE 9 S05v-06 B. — — 6 6 — — - _—
WAR EE 93 B. 1 9 - — _ = -- _—
XT. H 20.vi.06 M. — — 2 4-2 -- _ -- _
XCEV. JE 35 B. — = i] 6 _ o- _ _
XVII. H_ 28.vi.06 B. — 5 4-8 — —— _ _
XLIV. H_ 28.v.08 B. — — 1 5d _ — — _
EE ERY 408 Ss. - = 2 3-5-5:5 — “= -— —
1 PAVAG HE 15l 10.vi.08 B. — — 3 3-55 — = = —
LEX. 12.vi.08 Ss. — 2 4-5 — _— — _
Ibo EI s B. — -- 5 47 — _ - —
LXI. H 15.vi.08 B. — _- 2 5= “— -- — =
IDPs, IEL 19.vi.08 M. — — 14 3:27 — — — _
LXV ee B. — 5 7-8 — — _ -
XV EES EE a Ss. = -- 1 4 — — _ —
LXIX. H 23.vi.08 Ss - _ 16 46 — oo — —
LxXxX. H 35 M. — _— 49 45-9 — — — =—
LXXI. H 55 B. — -- 8 5-7 — - — _
LXXVI. H 2.vii.08 M. — —_ _ _ 1 + — _
LXXIX. H 15.vi.08 B. — — 1 10 348-6 — _—
XC By *20sviiz08" 5; eo _ _ _ 1 6 — _
XCVA. Fess. 09 2 4 4-2- — -- _ — _— _
LARVAL AND POST-LARVAL TELEOSTEANS. 361
TABLE XVIII.—Continued.
ReEcoRD OF SOLEA.
S. vulgaris. 8. variegata. S. lutea. S. lasearis.
No. of Haul. Date. Depth. No. Size. No. Size No. Size. No. Size.
mm, mm, mim, mm.
CI. H 24.v.09 Bows eased — -- — _ _ _
CII. H 2.vi.09 Me 5 — — — _ _ —
CIV. H a B. 1 6 — -- — — — _
CXVII. H 13.vi.09 S.. — 1 4-5 -— — = _
CXXIT. H 20.vii.09 B. — = 2 53-10 — = — —
CXXIV. H 6.viii.09 M. — — 1 5 _— _ _ _—
CXXV. H 35 B. — — 2 67 — — _ _
CXXXI. H 27.vii.09 M. — = 2 ca4 — — _ =
EAD 6.vi.13 Ss = _ —= 1 4-55 — =
1G, s72\ Ac Bs 1 6-86 = _ 3 3:7-5:3 — =
Pie AS Al vasls M. — _ 24 3:9-6:5 — — = =
View AQ 2 vals M. — — 2 5:-1-6:1 2 3-85-4-:9 — =
Wily A, bssviels M. 1 8-75 — = 1 651 — =
on Aw) USavdals Ss. = = 1 8 = — _ _
XIV. JA’ a B. — — 2 6-95-11 — = — _
XV. A bp M. — = 1 7-49 = = — _
XVI. A 19.vi.13 M. — _ _ — 2 5-7:35 — —
eV A: a M. — _ _ — 2 2 — _
XX. A 20.vi.13 5S... — _ 3 5-63 — — _ -
SX. A 27.vi.13 M. — _ 4 4-13-7 1 4-5 = =
XXIV. A 30.vi.13 B. — = 3 5:25-7 — — _ =
XXXITX. A 25.vui.13 8S. — = — — = = 1 5-025
XCVE, AC 25.vin.3"> By = — 2 885 — _ — _
XCVIII. A a M. — — — _ — — 3 6-9-5
C. A 27.vuil3. M. = _ -- on _ — 1 8
Cian A M. — — _ _ _ — ee LO-5
CIV. A 29.vii.l3 B. — _ = = —- _ 1 damaged
Cxe Ay ects B. — _ _ _ _ _ ih fei9/55
CXX. A 8.ix.13 M. — — - — =_ I) fez)
CXXIII. A 5 M. — — _ _ — — 1 4-5
CXEVE FAS 29x13 M. — = _ — — _ 1 Ml
CXXX. A 10.ix.13 M. — = — _— = = L 4-69
CLY. A 20ix.13 B. — — — — — _ ie Sie
CUEX VA 223i 13 B. — = = _— = = 1 1-25
CLXI. A a M. — _ -- _ _ — 1 as
CLXITII. A 24.ix.13 M. — —_ —_— — _ _— 2 7-10-5
CiXEX AW 25-113 M. — — — —_— _ _ 1 5:5
CLXXI. A 26.ix.13 M. — — _ _ _ — 1 5-786
CLXXII. A B M. — - =— — - ~ it Tere
CLXXIII. A as B. — — _— _ — _ Pe Li
CLXXXIT. A 30.ix.13 M. — — — -~ = _ 3 7-5—11-5
Solea vulgaris Quensel. S. variegata Don. S. lutea Risso.
S. lascaris Risso.
Four species of soles are found in the neighbourhood, and all are
represented in the post-larval material from the early post-larva up to
the metamorphosing stage.
These are: S. vulgaris Quens. Common sole.
S. variegata Don. Thickback.
S. lutea Risso. Solenette.
S. lascaris Risso. Sand-sole.
With a post-larval series of each, specific determination has been
362 R. S. CLARK.
comparatively easy. Of the four species, S. variegata (thickback) occurs
most frequently. The maximum number of post-larvee was in June.
They were taken in diminishing numbers on to August. This coincides
with the period recorded by Petersen for the capture of his post-larval
specimens—May to July. Records of S. lutea are confined to July and
August, but the number of individuals is extremely small. S. lascaris
occurred in increasing numbers from July to September, after which
month they disappeared from the pelagic hauls. 8S. vulgaris post-larvee
were taken in May and June, but were extremely few, and by no means
representative of the number of individuals in the neighbourhood.
S. vulgaris and 8. lutea show a higher frequency inshore at depths of
about ten fathoms or less, while S. variegata and S. lascaris have a dis-
tinctly low frequency for this area. The maximum for these two species
lies between the twenty and thirty fathom lines. Both were taken beyond
the thirty-fathom line, and it is possible, at least for S. varzegata, that
the frequency may increase with the distance from land. Our knowledge
of the life-history and developmental stages of S. vulgaris and S. lutea is
fairly complete. Kyle has remarked on the greater breadth of similar
forms of S. lutea from the more southern waters to those from the
North Sea. My specimens of S. lutea show a distinct gradation from
the one to the other. The greatest breadth (without the dorsal fin)
ranges from about 25% to slightly over 40% of the total length.
S. varvegata Don.
Post-larval S. variegata are known chiefly from the researches of
Petersen,* whose specimens were captured mostly over depths from
1000 to 4000 metres, though he recorded captures from 53 and 113
metres. The series ranged from 7 to 18-3 mm. in length. At the latter
length, metamorphosis was a long way off completion. It seems peculiar
that my specimens are equally well advanced in development, but at a
much smaller size. My post-larve of almost 4 mm. are closely identical
with Petersen’s 7 mm. post-larva, and just as far advanced in develop-
ment. At 1] mm. in my material metamorphosis has already reached
almost half-way. There is at a length of 11 mm., the largest post-larva
in my collection, a distinctive difference in pigmentation from Petersen’s
metamorphosed specimen. The pigment is not confined to the fins,
interspines, and margin of the abdomen and head, but also scattered
universally over the whole of the body, not as tiny black dots, but as
fairly stout stellate chromatophores of moderate size.
* Medd. fra Komm. f. Havund. Serie Fisk. Bind III, Nr. 1. 1909.
LARVAL AND POST-LARVAL TELEOSTEANS. 363
As Kyle* has remarked on his single specimen of 7 mm., the depth
of body is considerable. This is also a characteristic feature in nearly
all my specimens, and contrasts with the much narrower body of Peter-
sen’s post-larve. There is the further difference to be considered in
the localities of the two captures. The area of maximum intensity of
this species in the region investigated at Plymouth lies between the
twenty and thirty fathom lines, at no great distance from land,
whereas Petersen secured his specimens at considerable distances off-
shore, and over much greater depths.
The numerical characters of my specimens certainly agree with those
of S. variegata. D 71-72,
A 56-57,
Vertebre 9 (10)+29 (30) (31).
Petersen gave for his post-larvee D 71-76,
A 46-60 |
Vertebree 9 (10)+-29 (30) (31) (32).
Kyle’s single specimen of 7 mm. had 10+30 vertebre.
Structural and post-larval characteristics are much the same in my
specimens as in Petersen’s, except for those few characters noted above.
There is no trace of an air bladder nor of barred pigment. Holt and
Byrne have noted this barred pigmentation for the transition stage, and
Mr. Byrne has kindly supplied me with a note on a specimen 16 mm.
long (without caudal) having the general appearance of the adult. It
was taken 50 miles W.N.W. of Cleggan Head, at a depth of about 120
fathoms. The youngest specimen with the adult appearance which I
have observed at Plymouth measured 45 mm. Further investigation is
required, especially im the later metamorphosing stages, to arrive at a
fuller knowledge of this species.
S. lascaris Risso. (Sand-sole.)
Our knowledge of the post-larval development of the sand-sole is
extremely limited. It is confined practically to two specimens, one of
8 mm., described by Kyle in “ Rep. of the Danish Oceanographical
Expeditions, 1908-10, No.2”; the other of 11 mm., described by Cunning-
ham as a metamorphosing stage of S. vulgaris or S. lascaris in Journal
M.B.A., 1897-99. Ehrenbaum was the first to attribute this latter
specimen definitely to S. lascaris, and, from the material at my disposal,
there is no doubt about his identification being correct.
* Report Dan. Ocean. Exped., 1908-10. No. 2. 1913.
364 RK. Si CLARK.
Several adult S. lascaris have been trawled from time to time, prin-
cipally in Whitsand Bay, and I have thought it worth while to give a
record of their numerical characters. Nine of these specimens were cut
up and the vertebree counted. In the other eleven individuals the fin
formula alone has been recorded.
NUMERICAL CHARACTERS OF ADULTS.
1 80 65 46
2 90 76 48
3 85 70 46
4 87 69 46
5 87 71 47
6 86 70 46
a 81 66 47
8 83 67 48
9 88 72 46
10 80 67 _
11 86 70
12 86 69 _
13 91 73 —
14 84 69 _
15 82 71 =
16 85 69 —
17 85 71 =
18 87 73 —
19 91 73 _
20 82 68 —
Summary for 20 specimens :—
D 80-91 A 65-76 Vertebrae 46-48
Kyle gives D 79-89 A 61-70 Vertebree 47-48
My post-larvee give the following range :—
D 89-96 A 68-76 Vertebre ca. 47
There is thus an extension to Kyle’s summary, which works out as
follows :—
D 79-96
A 61-76
Vertebre 46-48
This large amount of variation seems to be a characteristic feature in
the genus Solea.
From previous records of the eggs of this species, and from the occur-
rence of the post-larval forms, spawning seems to take place during
June, July, and August. Hefford recorded the capture of one egg in
March, the resulting larva of which he described and figured.* HoltT
* Journ. M.B.A. Vol. IX. 1910.
} Sci. Trans. Roy. Soc. Dublin. Vol. IV,8. 2. 1891.
LARVAL AND POST-LARVAL TELEOSTEANS. 365
obtained the newly hatched larva at a length of 4-1 mm., but its appear-
ance was entirely different from Hefford’s specimen. The distinguishing
feature was a well-marked pre-cephalic expansion of the dorsal fin mem-
brane. It was taken much later in the year, and thus more in agreement
with the known spawning period than Hefford’s larva. My earliest post-
larve have all got this peculiar “hooded” structure, though much less pro-
nounced. There is distinct evidence in my specimens of shrinkage in this
region, so that there seems to be grounds for believing that this pre-cephalic
structure was indeed larger in the larval state. I am inclined to consider
Hefford’s larva, though not without great reservation, as belonging to
another species, possibly S. variegata. The pigmentation, shape of head,
depth of body, more backward position of the anus, and length of the
specimen seem to agree more nearly with the characters of S. variegata.
I have described and figured post-larval stages from 5-025 to 11:25 mm.
The rate of growth seems rather unequal, and considerable variation
is apparent. The metamorphosed specimen of 11-25 mm., though far
from having completed its post-larval growth, represents perhaps the
minimum length for such an advanced stage, as in specimens of 11-5 mm.,
the left eye has not even reached the dorsal margin.
S. lascaris Risso.
Fig. 5. Lenets 5:025 mm.
Length 5-025 mm., of which 3-4 mm. are post-anal. The preanal length
is about 2} times in the total, so that the anus is well in front of the
middle of the body. The snout is slightly longer than the diameter of
the eye. The lower jaw projects beyond the upper. The greatest
depth, which is measured over the middle of the abdominal region,
is slightly under three times in the total length. The development
of the fin rays is suggested posteriorly by the arrangement of the
dorsal and anal pigment. Hypural rays are developed. The verte-
bre have not advanced sufficiently to be counted. The snout is
compressed and notched where it receives the dorsal fin membrane.
The membrane curves back half-way over the nasal region and
parallel to it, and then rises almost vertically, giving the larva a
“hooded ” appearance. This feature is quite distinctive of S. lascaris,
and reminds one of Holt’s newly hatched (4:1 mm.) larva of the same
species with its “abnormal” development of this region. The mid-
brain is prominent ; it overlies the orbit and its anterior outline is almost
parallel to the anterior dorsal fin margin. The eyes are perfectly sym-
366 R. S. CLARK.
metrical. There is a distinct suggestion of an air bladder in a curved
line of dark pigment lying on the middle of the dorsal margin of the
abdominal region. As yet, there is no appearance of interspines. The
notochord is straight or nearly so. The pectorals are fairly large, and
equally developed.
The pigmentation is striking, and quite distinctive. The head, body,
and abdomen are covered with large, exceedingly delicate stellate
chromatophores, which assume a faint bronze tint in formalin. These
are largest on the abdominal region. A few dark stellate chromatophores
are present on the dorsal surface of the brain region. On the dorsal fin
membrane, and similarly on the anal, there is a large aggregation of these
chromatophores posteriorly, which assume a pronounced bar formation.
On the dorsal fin also are two large much darker chromatophores,
which stand out clearly from the rest of the pigment—one is situated
Fic. 5.---Solea lascavis. Length 5:025 mm. Oitthona Station, XXXIX. A. 25th July,
1913. Total depth 25 fms. Surface haul.
Del. E. Ford.
over the beginning of the notochord, the other about half-way along the
fin. A few delicate chromatophores are present on the anterior expan-
sion of the dorsal fin membrane, and near the large mid-dorsal chromato-
phore. The caudal is sparsely pigmented. Several chromatophores are
scattered over the anal fin in front of the posterior bar, while a row of
small dark chromatophores extends along the margin of the abdomen
to the tip of the snout. The dark curve of the air bladder has already
been mentioned. There are extensions in front towards the eye, and
behind as far as the downward curve of the intestine. An interrupted
line of pigment runs from behind the eye, on a level with its dorsal
margin, for a considerable distance along the notochord.
Fic. 6. LENGTH 6 mm.
The preanal length is considerably less than half the total length.
The snout is slightly larger than the diameter of the eye. The fin formula
cannot be counted, at least dorsally, though the anal fin rays are much
LARVAL AND POST-LARVAL TELEOSTEANS. 367
farther advanced. The vertebree number about 9+38=47. The lower
jaw still projects. The snout is decidedly more vertical and almost
continuous in outline with the dorsal fin margin, except for a small
indentation marking the origin of the dorsal fin. The dorsal fin
protuberance is almost parallel with the margin of the mid brain, the
anterior border of which is in advance of the orbit. The eyes are sym-
metrical. Interspines have developed. The first dorsal interspine hes
directly over the middle of the medullary region. The air bladder is now
well defined and is comparatively large—its length being almost equal to
that of the snout. The notochord is still straight.
The pigment is much more pronounced, though similar in arrangement
x ot SY %
Fic. 6.—Solea lascaris. Length ca. 6mm. Oithona Station, XCVIII. A. 25th Aug.,
1913. Total depth 36 fms. Midwater haul.
Fic. 6a.—Chromatophores enlarged.
Del. E Ford.
to that in the previous specimen. Chromatophores are developed on the
snout and on the brain region, which latter is distinctly marked by a line
of dark pigment, stretching from the fore brain, over the mid brain, hind
brain and medulla, and ending with the beginning of the notochord.
The notochordal line of pigment is less interrupted, and reaches almost
to the caudal. This line of pigment marks out the ventral aspect of the
spinal chord. An interrupted line of pigment runs along the base of the
anal interspines, becoming more distinct in the region of the posterior
bar of pigment.
Fic. 7. LENGTH 7°75 mm.
The preanal length is 3-42 mm. The snout (measured from the tip of
the upper jaw to the anterior margin of the eye) is about equal to the
368 RisSc CLARK
diameter of the eye. The dorsal and anal fin rays have advanced con-
siderably and stretch half-way across the fin membranes, though not
sufficiently clear on the distal portions of the fins to be counted with
accuracy. Vertebree number approximately 9+37. The notch in
front of the origin of the dorsal fin is much more conspicuous. It
overlies the region of the mid brain. The interspines have extended
forwards. The tip of the notochord is bent upwards, and the caudal
rays are developed : twelve rays can be counted.
A few stellate chromatophores have collected round the two large
separate dorsal fin chromatophores at positions corresponding to the
future pigment bars. The first anal bar is also suggested by an aggrega-
tion of similar chromatophores at the beginning of the anal fin.
ss ERT OE RE
at UA eA ANY se AK -
+. J a eh ear $ute aA
Ape te A®
YS mm.
—————,
Fic. 7.—Solea lascaris. Length 7°75 mm. Oithona Station, CLXXII. A. 26th Sept.,
1913. Total depth 27 fms. Midwater haul.
Del. E. Ford.
Fig. 8. LENGTH 8-7 mm.
Length 8:7 mm., of which 5-69 mm. are post-anal. The anus is thus
well in front of the middle line. Length of snout ca. -5 mm. (measured
from tip of upper jaw) ; diameter of eye ca. -4mm. The greatest depth
is slightly more than the preanal length. Length of air bladder about
equal to snout length.
Fin formula D ca. 89.
A ca. 73.
Vertebree 9-++ca. 388=ca. 47.
The snout is more rounded and swollen anteriorly, and extends
backwards to the origin of the dorsal fin membrane, which pro-
jects as a small knob in front and above the mid brain, the anterior
margin of which is in line with that of the orbit. The dorsal interspines
have advanced to a level with a vertical line through the middle of
LARVAL AND POST-LARVAL TELEOSTEANS. 369
the eye, and are well developed. The lower jaw still projects a little,
and the mouth has a downward curve. The eyes are symmetrical.
The tip of the notochord is bent upwards, and the caudal rays are
almost fully developed.
The general appearance of pigment is very much the same as in the
last specimen. There are now three distinct barred regions in the dorsal
fin and two inthe anal. The median dorsal bar lies exactly opposite the
anterior anal bar, while the posterior dorsal bar seems to be continued
across the body on to the anal fin. The two large separate dorsal fin
chromatophores have disappeared, and their place is occupied with the
median and anterior aggregates of chromatophores. Distinct dashes
Fic. 8.—Solea lascaris. Length 8°7 mm. Oithona Station, CXX. A. 8th Sept., 1913.
Total depth 25 fms. Midwater haul.
Fic. 8a.—Chromatophores enlarged.
Del. E. Ford.
of black pigment are present along the bases of the interspines dorso-
ventrally, but fewer in number and of larger size dorsally. Black
dots occur on the chin, along the abdominal margin and on the anal
fin, but these are obviously the centres of extremely delicate stellate
chromatophores. The caudal fin is weakly pigmented—a few chromato-
phores occurring near the base and along the lower rays. The specimen
is equally pigmented on both sides.
Fic. 9. LENGTH 9°5 mm.
The snout is larger than the diameter of the eye by about 3. The
greatest depth is slightly more than the preanal length.
Fin formula D ca. 89.
A ea, “71:
Vertebree 9+ca. 38=ca. 47.
The concavity of the snout and dorsal fin membrane is clearly V-
shaped. The mid brain has receded and on a level with the last third
of the orbit. The eyes are still symmetrical. The lower jaw is practically
370 R. S. CLARK.
on a level with the upper, but the chin projects, while the curve of the
mouth is even more pronounced than in the previous specimen. The
dorsal interspines have reached beyond the mid brain, and in line with
a vertical through the middle of the orbit.
The pigment is much as in the previous specimen, with the barred
areas forming a distinct feature. The spinal chord is marked out above
and below by a continuous row of small dashes, while across the base of
the caudal fin the chromatophores appear to be arranged into another
small transverse bar.
So) 20
Fic. 9.—Solea lascaris. Length 9°5 mm. Oithona Station, XCVIII. A. 25th Aug.,
1913. Total depth 36 fms. Midwater haul.
Del. E. Ford.
Length 10:0 mm. The preanal and post-anal lengths show the same
proportion as in the previous specimens. The snout is also longer than
the diameter of the eye.
Fin formula D 89.
AP it
Vertebree 9+38=—47.
The concavity of the snout is still well marked, though not quite so
markedly V-shaped. The left eye has begun to migrate. The inter-
spines have advanced beyond the vertical from the anterior margin of
the left orbit, which is slightly im front of the right. The brain has re-
ceded, and the anterior margin of the mid brain overlies the middle of
the right eye.
There is practically no difference in pigmentation from the last
specimen.
Fig. 10. Lenetu 11 mm.
Metamorphosis has gone a stage farther. The left eye is almost clear
of the right, but has not yet reached the dorsal surface. The snout is
more or less ‘‘ hooked,” with the lower arm of the V-shaped concavity
LARVAL AND POST-LARVAL TELEOSTEANS, 371
almost horizontal, round which the left eye will undoubtedly travel.
The abdomen is beginning to get enclosed.
Fin formula D 89.
A ca. 68.
Vertebree 9+38—47.
Fic. 10.—Solea lascaris. Length1l1mm. Ozthona Station, CXXV. A. 9th Sept., 1913.
Total depth 25 fms. Midwater haul.
Del. E. Ford.
Large exceedingly delicate stellate chromatophores are diffusely
scattered over the head, body, and abdomen. The dorsal and anal fins
retain the darker barred aggregates, while a similar bar is present on
aS.
Fic. 11.—Solea lascaris. Length 11:25 mm. Oithona Station, CLIX. A. 22nd Sept.,
1913. Total depth 27 fms, Bottom haul.
Del. E. Ford.
the base of the caudal fin, the posterior half of which is devoid of
pigment.
hie ti. Lencra 11-25 mm;
Length 11-25 mm., of which 8-5 mm. are post-anal. The preanal
length has considerably lessened. The left eye is almost wholly in
NEW SERIES.—VOL. X. NO. 2, JUNE, 1914. 2A
372 Ry Si CLARK.
advance of the right, which is contained about twice in the snout length
(reckoned from tip of snout to margin of right eye).
Fin formula D ca. 96.
A ca. 16.
Vertebre 9+37 (38)=46 (47).
The upper lip on the right side is curved as in the adult. Teeth are
not developed on the right side, though present in the lower jaw on the
future blind side. Both eyes are on the right side, and the dorsal fin has
erown forward on to the middle of the snout so that the concavity has
been overgrown. The abdominal region is entirely enclosed. The
ventrals are equally developed, and reach almost to the first anal ray.
There is still no trace of the large fringed nostril on the blind side. The
air bladder is rather large.
The pigmentation agrees closely with the preceding stages. Both
sides are equally pigmented, so that the permanent bottom stage has not
quite been reached. The small dark chromatophores which are present
on the abdominal margin of the previous stages have now collected into
a dense ageregate over the anus. Stellate chromatophores are univer-
sally distributed, and extremely delicate, having a rusty - brown
appearance. The three dorsal and two anal bars are still quite distinct,
while the smaller bar across the base of the caudal has practically
disappeared.
This stage is much farther advanced than Cunningham’s 11 mm. post-
larva. There are six more dorsal rays; the abdomen is enclosed and
ventrals are developed. The rough saw-like margins of the dorsal and
anal fins are quite typical, and the rays in my specimen reach the tip of
each tooth.
GOBIID.
Gobius minutus Pall. G. microps Kr. G. scorpiordes Coll. Crystallogobvus
nilssont Diib. and Kor. Aphya pellucida Nardo.
Table 25 gives a record of the gobies, without any definite specific
arrangement, These are chiefly G. minutus, though G. microps, which
appears to be quite a distinct form, is also well represented.
G. scorprordes Collett.
One specimen, 11 mm. in length, was taken in a midwater haul (192 A)
on 24th October, 1913, 6 miles west of Rame Head, over a depth of 26
fathoms. Previous records of this small goby have been remarkably
few, and, as Holt and Byrne have remarked, there is little chance of its
being taken unless by special methods. Two adult specimens were
LARVAL AND POST-LARVAL TELEOSTEANS. 373
taken by Crawshay* in the outer western area of the English Channel,
31 and 33 mm. in length, at a depth of about 50 fathoms.
The pigmentation of the single specimen recorded differs considerably
from that of the full-grown adult. Two conspicuous pale bands are
represented. One lies across the caudal peduncle, as in the adult; the
other occupies a position directly behind the head in the region of the
pectoral and first dorsal fins. A faint yellow tinge is present on the
caudal and pectoral fins, while alternate dark and light bands are present
on the dorsal fins. Pigment is very sparing on the ventrals, being
limited to a few dark splashes at the base and on the middle of the
larger rays.
Crystallogobius milssoni Diib. and Koren.
Adult Crystallogobius are frequently met with in the neighbourhood,
being especially numerous on the Eddystone Grounds. Sexual dimor-
phism is a distinct characteristic. The males have considerably more
pigment than the females, while the body is deeper and more compressed
laterally than in the female, which has a much more slender body and
more pointed head. The first dorsal fin is present only in the male, and
contains two long rays. The second ray is the longer, and is joined to the
body by a wide membrane.
In June, adult males were found in attendance on the eggs, which
were attached to the inside of empty tubes of Chetopterus variopedatus.
These were trawled on the Eddystone Grounds, chiefly in the area south
and west of the Eddystone rocks. A similar habitat was noted by Grieg,f
who observed the eggs of this species inside tubes of C. sarsv.
The records of this species confirm Holt’s observations on the pelagic
habit of this transparent goby. The young stages have not been suffi-
ciently cleared up to give a definite idea of the distribution and life-
history of the species.
TABLE XIX.
RECORD oF CRYSTALLOGOBIUS NILSSONI DUB. AND Kor.
No. of Haul. Date. Depth. No. Size.
VET Ep 30.v.06 Ss. 6 24-30
x Et 20.v1.06 B. 86 21-5-36:5
XXVIII. H 21.1x.06 13}. 1 22
IDPs shes 15.vi.08 B. 6 22-36
CXXIV. H 6.vill.09 M. 1 29
CXXV. H - B. 3 29-30
SK? AL 16.vi.13 B. 1 24
oi A 18.vi.13 M. 31 23-28
XIV. A a BS 14 20-30-5
C@ xan A Sebselics Ss. 1 28
CXCII. A 24.x.13 M. 102 14-26-5
CXCIII. A = B. 93 14-21-5
CXCIV. A 35 M. 17 138-25
* Journ. M.B.A. N.S., Vol. IX. 1910-13. t Bergens Museums Aarbog. 1898.
374 Re S.CLARK:
GOBIUDA.
Aphya pellucida Nardo.
The post-larval stages of this species are very much like those of
Crystallogobius, from which they have been separated with difficulty.
The fin formula has been counted in most of the specimens, and has given
D 11-12, A 11-12. In a few of the older post-larvee the rays of the first
dorsal were just visible.
Post-larvee occurred from June to September with a maximum in July
and August. Spawning would thus be at its height in June and July.
Post-larve of A. pellucida are seen to be widely distributed over the
area investigated, though frequency is highest within the ten-fathom
line.
TABLE XX.
REcORD OF APHYA PELLUCIDA NARDO.
No. of Haul. Date. Depth. No. Size.
I, A 6.v1.13 13}. 53 7-7-10-5
INUE, AN. 11.vi.13 M. 4 6-02-11-4
Vo FA 12.vi.13 M. 4 6-3-8
aXe, VA: 13.vi.13 B. 1 8-4
XXXVI. A 8.vil.13 — 4 8-5-10
DOr WATE, AN 10.vui.13 Ss. I 9
DOXSViLTTS A IE avabigt es) M. 8 8-11
DOIG AN 5p S. 1 Wei
XXXII. A 14.vi.13 Ss. 2 8-3-8-68
XXXII. A 15.vii.13 B. 3 8.5-11-5
XXXIV. A 16.vii.13 M. 1 6
XXXV. A 17.vu.13 S. 21 6-14:5
XXXVI. A 18.vi1.13 M. 5 6-9:5
XXXVII. A 24.vii.13 B. 7 5:5-12
XXXVIII. A SS M. 9 6-5-12
XL. A 28.vu1.13 M. 12 10-5-11
XLI. A =: M 61 8-16
XLIT. A 26 M. 11 6-5-12-5
INOS AN ae Ss. 5 damaged
XLIV. A 29.vi1.13 8. 1 8:5
Vil, WAY 53 M. 32 7:5-10:5
SD NAUI, JN 30.v11.13 Ss. 1 11
XLVIII. A 35 B. 14 4-5-10-5
XLIX. A 31.vii.13 B. 3. 7-T7:5
LIT. A 1.viui.13 Ss. 17 4-5-12
LIV. A 2.vill.13 Ss. 33 4:5-16
Ve AS 5 Ss. 42 3-16:5
Dial 9 AL 35 M. 23 5:5-18
LVII. A 5 M. 13 12-5-16
LVIII. A 5 S. 16 8-17
LX. A 7.vili.13 S. 1 8:5
xa VA 53 M. 7 44:5
LXII. A 55 iB: te. 5-7
Xai At 53 M. 5 3:14-8
LXIV. A 11.vii.13 M. 3 ca. 6
LXV. A A B. 2 3-68-12 5
LXXI. A 13.vili.13 S. 128 4-14
LXXII. A an Ss. 158 4-5-15
IpPOHHh, AN S. 49 4-5-12-5
33
LARVAL AND POST-LARVAL TELEOSTEANS.
No. of Haul,
LXXIV.
LXXV.
LXXVI.
LXXIX.
LXXXIX.
XC.
XCII.
XCV.
XCVI.
XCVII.
XCIX.
CI.
CII.
(OPE
CLVI.
CLX.
CLXV.
CLXX.
CLXXIV.
CLXXIX.
CLXXXIV.
TABLE XX.—Continued.
RECORD OF APHYA PELLUCIDA NARDO.
Date. Depth. No.
A 13. viii. 13 M. 154
A x 8. 8
A 14.vili.13 8. 14
A 18.vili.13 13) 3
A 22.vili.13 B. 2
A oF BE 27
A 25.vill.13 M. 2
A 5 M. 2
A 3 15}. 2
A 5c BS 4
A 26.vui.13 M. 2
A 27.vill.13 M. 4
A 5c M. 1
A SB} 1) M. 8
A 20.ix.13 M. 3
A 22.1x.13 B: 1
A 24.ix.13 B. 1
A 25.1x.13 iB: 1
A 26.1x.13 B. 1
A 29.ix.13 iB: 3
A esxals 183; 1
COTTIDA.
Cottus bubalis Kuphr.
375
Size.
3-14
5-15
4-5—-12
8-5-11
9-14-5
4-5-14
8-14°5
Spawning begins in January. Eggs were taken attached to stones
between tide-marks on Drake’s Island. Post-larve occurred from March
to June, with their maximum in the last month.
No. of Haul.
XIV.
XVII.
XXXII.
XXXII.
XXXITI.
XXXIV.
XXXV.
XLIV.
LVIII.
LXVI.
LXVII.
LXVIIUII.
XXIV.
XCV.
XCVI.
XCVII.
XCIX.
CIV.
CIX.
aoffsnfanpeegangceonen gon juejanjusjasjasicshasyssiseiseississianisy
Date.
22.v.06
30.v.06
20.vi.06
28.vi.06
25.11.07
11.iv.07
6.vi.07
28.v.08
10.vi.08
19.vi.08
39>
30.vi.08
28.iv.09
3.v.09
13.v.09
2.vi.09
25.v1i.09
Depth,
TABLE XXI.
RECORD OF COTTUS BUBALIS.
Z
{=}
AWB ~WHR~ HRW ~ HWE SeYOnnnEe”
NDE WEE TEN REND NORREF OPN WH WD
eh
is
ne
Sad
Hey
376 BR, SOLAR,
CYCLOPTERIDA.
Cyclopterus lumpus L. Cyclogaster montagui Donov.
Cyclopterus lumpus L.
Only one specimen of the lumpsucker is recorded. It was taken in
the Zostera bed of Cawsand Bay in a midwater haul on 24th September,
1913. The total length was 18 mm.
Cyclogaster montagut Donov.
Post-larvee of this species occurred most frequently in June, at lengths
ranging from 3to 7-07 mm. The capture of two specimens 5-6 and 6-7 mm.
in length in August and September, in bottom hauls, seems to suggest
a long post-larval life. In these, the sucker was well developed in front
of the abdomen, as in Ehrenbaum’s Fig. C, “ Nordisches Plankton,”
Vol. I.
TABLE XXII.
RECORD OF CYCLOGASTER MONTAGUI.
Cyclogaster montagui,
No. of Haul. Date. Depth. No. Size.
Va. SEE 30.v.06 iB: 4 4-5-6
Wau) Jel Bs 8. 1 7-5
WADIA S EL > B. IP veass
xo El 20.v1.06 B. 1 7
XVII. H 28.v1.06 B. 2 4-5-6
DON El 20.vil.06 iB: It 6
DORI Tel 27.vi1.06 B. 1 5:5
XXXV. H 6.v1.07 IBS 69 ‘caso
a Et 4.vi.08 8. 1 6
TI OXSVilii) SE 19.v1.08 1B} 1 8
xXex., WEE 23.v1.08 M. iL 6-7
LXXI. H 3 18% 2 4:3
OAS dal 10.vi.09 iB: 2 ?
CEXe Ee 25.v1.09 B. 1 7
arg Ja 18.vi.13 iB: U 7-07
XCVI. A 25.vi.13 iB: 1 5-695
CLX. A 22.ix.13 18% 1 G7)
TRIGLID A.
Trigla gurnardus L. T.hirundo Bl. T. cuculus L. T. lineata (Ray).
Our knowledge of post-larval gurnards is extremely limited. Only
T. gurnardus and T. hirundo, two of the five species that occur at
Plymouth, are known with any degree of certainty. Tragla gurnardus
is well represented in the collection, and appears to be the com-
monest post-larval form. T. hirundo has been partially worked out
by Emery* for the Mediterranean, and his descriptions of the post-
* Mittheil. Zool. Sta. Neapel, vi, 1886.
LARVAL AND POST-LARVAL TELEOSTEANS. 377
larval forms have been extremely helpful. Specific characters which
have been found most useful have reference to the pectoral fins.
These are extremely long in TJ. gurnardus, and have the pigment
scattered as black dots between the rays mostly on the posterior half of
the fin. In 7. hirundo the pectorals are much shorter and broader, more
deeply pigmented over the whole surface, and appear almost as a uni-
form brownish black.
An entirely different form appears in August and September. This,
by a process of elimination, is most probably 7. lineata, which is known
to spawn about July. The early post-larva has very little pigment
except for a distinct narrow dark band along the dorsal and posterior
margin of the abdominal region, somewhat similar to what occurs in
Cottus bubalis.
With the material at my disposal, I hope to give a fuller account of
the different species in a later contribution.
TRACHINIDA.
Trachinus vipera Cuv. T. draco L.
T. vipera Cuv. (Lesser Weever.)
Pelagic post-larve of the lesser weever were found to be generally
distributed and comparatively numerous. They were taken at the
mouth of the Lynher River, in the Sound, Cawsand Bay, and over
depths ranging from ten to about forty fathoms. The frequency was
highest beyond the twenty-fathom line. They occurred from April to
September, so that the spawning of this species, as with the dragonet, is
indefinitely prolonged. The maximum for the post-larvee hes in July and
August.
T. draco L. (Greater Weever.)
Records of the greater weever are limited to four specimens from
6 to 7 mm. in length, secured in August and September. The appear-
ance of these post-larve corresponds to Ehrenbaum’s Fig. f, ‘* Nor-
disches Plankton,” Vol. I. Adults of this species are by no means
common in the neighbourhood. Those which have been observed have
been captured in deeper water.
TABI XX.
RECORD OF TRACHINUS DRACO.
No. of Haul. Date. Depth. No. Size.
mm.
XCIX. A. 26:vii.13 M. 2 6-7
CXVII. A. 5.x. 1S M. 1 6
CLXXVI. A. 26.ix.13 B. 1 6°5
378 R. S. CLARK.
CALLIONYMIDA.
Callionymus lyra L.
Hefford recorded the eggs of the dragonet from 11th February to
30th August, but they have been observed this year in January. There
is thus an indefinitely prolonged spawning period in the Plymouth
district. This is borne out by the post-larval records, which extend from
March to September, with a maximum for the middle months of the
year—May, June, and July. The distribution of the post-larve is
general, but there is a distinct concentration in numbers between the
twenty and thirty fathom lines, where the adults are also very numerous.
The frequency is low inshore within the twenty-fathom line. Between
the ten and twenty fathom lines, and also between the thirty and forty,
the percentage is fairly high, and shows only a slight decrease from the
numbers in the area included between these two regions.
GOBIESOCID Ai.
Lepadogaster bimaculatus Donov. L. gouani Lacep. L. candollet Risso.
The distribution of these three species is well marked by the records
in Table 24. There are two types represented—the littoral type in
L. gouant and L. candollez, and the deeper. water type in L. bimaculatus.
The frequency of L. bimaculatus is high beyond the twenty-fathom line
and low in depths less than twenty fathoms. Post-larval L. bomaculatus
occurred from June to September with a maximum in July. Spawning
thus begins in May and extends to August. Ova were frequently found
in June and July attached to the inside of empty pecten shells taken in
the otter trawl on the Eddystone Grounds. Adult males were generally
in attendance.
TABLE XXIV.
ReEcorpD or LEPADOGASTER SP.
L. bimaculatus, LL. gouani. L. candollei.
No. of Haul, Date. Depth. No. Size. No. Size. No. Size.
XIV. H 20.vi.06 BE 12 7-5-11
XVII. H 28.vi.06 18}. 4 4—7 _ — — =
XIX. H 20.vii.06 S. — — 1 5:5 19 4-5-7-5
2O lel 3 M. Il 5-5-10:5 — _ 2 5-6
XXI. H 27.vii.06 uy 25 5-105 — _ — =
9 OG al 5 ? 6 4:7-10 — — 1 6
SOV, 2x06 B. 1 17 _— — _ =
XXXV. H 6.vi.07 iB. 9 6-10 -- — = =
XXXIX. H 10.vii.07 B. 3 5-6 _ _ — =
XL. H 19.vii.07 B. 1 u — _— — =
XLII... H 28.v.08 M — —_ 3 5-6 _ =
XCViI TEL 3:v209 2 — = 1 4:6 _— _
CLIVE ER 2tva109 B. 1 8) _ = = =
LARVAL AND POST-LARVAL TELEOSTEANS. 379
TABLE XXIV.—Continued.
REcorRD OF LEPADOGASTER SP.
L. bimaculatus. L. gouani. L. candollei.
No. of Haul. Date. Depth. No. Size. No. Size. No. Size.
CXVIII. H_ 13.vii.09 M. 3 6-75 — — _ _
CXXI. H 20.vii.09 2 9 6-10 — — = _
CXXII. H es 2 11 5-8 — — — _
CXXV. H 6.vii.09 B. 5 5-T5 — — — _
iti VAs levaslS M. 1 5:32 _ a — _
V. A 12.vi.13 M. 1 6 _ -- -_ --
ey AN Geyinls B. — — il 7-46 -- —
XX. A 24.vi.13 Ss. 1 5:18 — — -- —
XXV. A 7.vii.13 B. _ — — — 1 6-02
XLVI. A 29.vii.13 M. it 8-5 _ — aa —
XLVIT. A 30.vii.13 S. _ — _ — 1 7-5
>A \AMUIS, aN 5 Be _ _~ = — 5 6-8
RST DXS AS Seva 13 B. 1 9-5 — — _ a
ii A Svan ls S. 1 mtd. — =— — _
VVaS AL 2svai. iS M. 1 8 — — — -
LVIll. A = S. 8 55-10 — _— —
LX. A 7.vui.13 Sa _ _ —_ 1 7-5
ILPSIB OTS. ¥4\ a M. 2 6-65 — = — =
EPXeXaiS VAS SUS evinies S. 2 5:025-6-628 — oa _—
LXXx. A _ 18.viii.13 M — _— 5:5 1 7
EXON AC 22S vail loys _— _ 1 6-5 1 7-5
MCI VAY 25:vill. 13) Mi: 1 10-5 — — — —
XCV. A 5 M. il 7 — _ - _
XCVI. A 53 18} 1 6 — _ o- _
XCVIT. A 5 B. 3 5-7 — — - _
XCVIIL. A 0 M. 1 7:5 -- — = —
Ch TAS 2ievait tS VE: 3 u — ~— a --
OXViN VAS) DiS M. 2 75-9 — _ — _
CXXVI. A 9ixl3 B. 1 5:5 _ — — _—
BLENNIID 2.
Blennius pholis L. B. ocellaris L.
Considerable difficulty has been experienced in determining all the
individuals specifically, owing to our incomplete knowledge of the early
post-larval stages. Records will be found on Table 25, a general survey
of which reveals the presence of two main types, those forms which
occur most frequently offshore, and those with a higher frequency in-
shore. The offshore type is represented by B. ocellaris, the inshore
chiefly by B. pholis.
Eggs of B. ocellaris were found continuously from June to August
inside empty Buccinum shells which were trawled on the Eddystone
Grounds. In nearly every case an adult blenny was taken in attendance.
Several of these adults were measured and gave lengths of 120 and
130 mm.
380 BR. S. CLARK
TABLE
EXPLANATION OF
ec = several thousands.
m = many.
vem. = very many
Ctenolabrus
Clupea sp. Ammodytes sp. Labrus bergylta, rupestris, Arnoglossus sp.
No. of Haul. No. Size. No. Size. No. Size. No, Size. No. Size.
Eb -- = — — — — — -- =
Il. H — — — _ — — _ a — —
ID GIS 1eL he 12-24 4 10-29 3 7 — a — —
LV. 3 9-10 a= — a _— — — — —
V.H 70 18-30 _ _ = _ — — — _
Walz deh 7 9-165 14 6-17°5 a 4-5-7 oa oa — _
Wills isl ee 26-47 1 12 _ — me ~ -— _
WOUND ek i 11-5 1 10 _ a — — — --
ID, lal il 22 1 10-5 2 4 -- _ 1 4:5
XH 4. 10-12 2 9-15 3 4-7-6 — 1 4-5
2G Jal z! 17-20 1 11 1 6 a —- -— —_
OE ae 2b 10 — —_— -- 2 5:5-7
DUO 181 23 12-20 3 10-17 — = — -- aa —
VEE 13 = — 1 24 3°9-4-5 1 5:5
3QWE EL 5) 9-1] 1 7:6 60 3:7-5:5 14 3:8-4:5 1 4
XVI. H 66 10-5-19 28 6-5-18 4 47:5 _ — 3 5-7:°5
SO WANIG TEL al 18 _ a _ _ — _ = —
OVA 22 11-24 3 7-125 56 3-25-7 a 5-8 —
XIX. H 23 10-5-16-5 4 7-165 — — 3 6-5-8 1 6-5
EXOXG GE a7) 15-20 12 8-23 1 1:3 3 8 = —
EXOXG SET a. 12-5 1 Ly 3 4-2-7 1 7-5 — =
XXII. H — _ - — = = — “= — -
XXIII. H — _ — _— a= — a= -= _— —
XXIV. H — _ — — — — — 18 13-26
XXV.H — — — _ - _ ~ — 1 26:5
XXVI.H — — = — = — a 2 19-21
OXGVA Ee 22 4-5-18 1 15 _ _ _ _ _
XXVIII. H — — — — — _ -- _ -- _
XXIX. H — _— _— - = _ — _ -- _
XOX Ed 7 —_— — — os — _
XXXII. H 14 10-20 1 8-5 — a _ _ — _
XXXII. H 10 3-5 _ — = — — _ — _—
XXXIJI.H 15 5--14:5 3 65-12-55 — — = — —-
XCXOXCV ep ED 7-11 3 7-8 = — _ — — —
EXEXGXGV SSE 9-12 — ~- 2 a — -- — _
XXXVI. H — — — — — — — — -
XXXVIT. H — _ _ — 1 5 — _ — _
XXXVIII.H — — _ _ 6 = — _ _ _
XXX EL 16 — = 1 aa — — — _-
XL. H — - 12 13-22 2 8-20 — — — =
XLI. H 20 9-18 ~ _ — —_— = — — —
XLIL.H 8 4 — — — — — _ _— —
XLII. AH — _ —- -_ ~ _ = _ _
XLIV. H 27 11-21 oa _— 3 5-7:5 — _ = =
XLV. H — — — - _ — - _ _ _
XLVI.H 4 10-12 — os — a _ — _ —
XLVII. H 6 12-16 1 23 _ — _ — — =
XLVI. H 1 10 1 11 — _ _ = =
XLIX. H 2 12:5-13:5 — = -— -- — — —_ —
iby del 7 10-17 7 7-125 — — _ — = =
LEER 2 8-9 —_ = _ — — = = =
LI. H — _ — — — _ = _ — —
LIT. H 30 7:5-16 — a = _ 1 7-5 — =
Ve Hey 2 13-16 — — — - _— = — =
LY. H — — _- _ oo — _ — =
LARVAL AND POST-LARVAL TELEOSTEANS.
XXV.
ABBREVIATIONS.
Z = damaged specimen.
size = length in mm.
Scophthalmus
norvegicus, Gobius sp.
No. Size, No. Size
— _ 1 7:3
— — 22 5-9
25 5-8 2 ?
] 10-5 2 7-15
19 4-9 8 4-8
_ _ m. 6-17
—_ —- 3 4-4-5
_ _- 150 5-13
1 u _— —_
3 5-5-6 26 6-10
_ — 40 4-5-11-5
—- 2 ca. 5-5
28 4-5-9 10 3-6:3
-- — 200 3-5-10
_ —_ 4 7-11
3 5-6 — —
1 6 168 3-5-16
_ — 160 5-13
— _ 31 4-10
2 5-8 12 5-8
1 6 _— —
4 6-9 10 7-9
_ _ 1 12
28 _- _—
80 - — =
6 5-8-5 70 4-5-10
— -— 1 6
— — 6 4-5
-- — 14 4-7:5
a —_ 1 5
_— — 4 5-8:5
a = 54 3:2-15
-- — 720 4-11
14 5:5-8-2 32 4-7:8
= ] ll
|
|
i
or
Trigla sp,
No Size.
2 9-10
13 7-11-5
1 is)
5 5 5-7-5
38 7:-5—11
1 8-5
4 7-5-12
3 5-8-5
4 7-12
il =
1 5
1 a
3 7:-5-17
1 17
2 10-17
2 10-17
3 8-9
1 6
Trachinus
No.
Se ISSEY SUP Se [at ae ten Tt GU tso: cic cot cs eet tess ce oem cet =n |
vipera.
Size.
Callionymus
No.
Brown | CRT HwwS]e| wa] | |
lyra,
ease Genge
Spon
|
Rey tN
381
Blennius sp.
No Size
1 5:9
1 5:5
5 ca. 4:5
20 4-6-6
67 4:-7-6-5
20 4—6
1155 4-5-9
7 4-8
1 6
1 8
1 4
14 —
19 =
2 4-5-5
1 5
1 5
1 5
1 5
382 R. S. CLARK.
TABLE XXV.—
Ctenolabrus
Clupea sp. Ammodytes sp. Labrus bergylta. rupestris. Arnoglossus sp.
No. of Haul. No. Size. No. Size. No. Size. No. Size. No. Size.
LVI. H — — _— _ _— = — — _ a
LVII.H 4 10-20 — — = — — = _ —_
LVIII. H 32 10-19 9 7-15 3 5-5-9 1 9 _ —
LIX. H 8 8-15 14 6-10 — — _ —_ —
Ne EE 7 10-18 1 7 a 7-11 — — _ —
LXI.H 9 10-14 _— — 3 5-6 _ — — —
xa 2 8-15 — —_— — — — _ _ —_
IDPS 18E 33 9-12 —_ — — — — _— — —
RST tee 11-23 4 11-15 2 4-7-5 1 6 —_ —
LXV. H 19 11-23 8 7-9 _ _ — _ _
LV; A 25 9-24 1 14 — — -= —_ — —
ESV 6 _ 5 _ — _ _ —
LXVIII. H 2 10-12 = _ 3 3-8:5 — = = =
LXIX. H — — 2 7-11 _ _ — — — —
LXX. H 53 17-18 29 6-21 5 3°7-7 1 uf — —
1DPONIG JEL saat, 8-20 — _— 17 7-12 — _ —
LXXII.H — — — —- 1 4 — — — —
LXXIUI. H — — — = 6 6-10 oa — — —
TEEXOXSHVE EL 58 8-15 5 7:5-13 3 5:5-6:8 — = _ _
LXXV.H 6 9-11 2 7-9 - — — — — _
LXXVI.H 1 10 _ _ 7 3:°5-5 1 5:5 — —_
DXOXSVil. Et 18 23-27 — — 4 3-10 — — = =
LXXVIII.H — _ oe 4 6-7-5 = — _ _
LXXIX. H 6 13-15 11 6-13 13 3-7-5:5 2 6-9-5 — =
LXxXX. H 40 10-15 8 8-13 7A 35-11 — _ _—
LXXxXI.H 2 7-10 68 5-20 3 — _ — _ —
LXXXII.H 3 7:5-12 33 d=12°5)) 17 4-5-6 14 4-7 2 4-6
LXXXTII. H — — — _— 19 4-5-7 4 4. 3} 4-6
LXXXIV. H 1 17 3 9-17 _ — 1 4:7 _ —
LXXXV. H — — al 7-13 _ — — _— _ _—
LXXXVI.H — — 3 8-17:5 — — — _ 2 7:5-8'5
LXXXVII. H — — 13 5-16 1 9 = =
LXXXVIII. H — — 6 7-17 J 4 5 5:55-7:30 =
LXXXIX. H — — I i 2 4-5-7 — _— 1 3:9
XC. H — — a 19 — _— _ _ _ _—
XCI. H — — — _— —_ — 2 75-8:5 — =
XCIT. H — — 2 — — — — — — _
XCITI. H — — — — — _ — _— —_ =
XCIVieE ss 20 — — 2 3-5-4 — — _ —
XCV. Hi 2 7-9 —= — = = = = == =
XCVI.H 5 8-15 1 12 _ — — _— _ =
XiCVAT. Ed 24 1 27 — _— _ _ = =e
XCVIII. H 5 22-26 — — _— — _— — — —
XCIX. H 4 12-17 = = — i _ — — —
C,H 1 20 = _— _ —_ — _ — =
(Clg dal 3} 22-27 _— — — — _— _ _ =
CIl. H — — —_— -- - — _ — = _—
CIIl. H 18 12-17 — _— 1 10 _ = = =
CIV. H 20 12-17 9 16-32 2 6 _ —_ — _
CV. H — —~ — -— 1 8 _ _ _ _
CVI. H — “= — _ — = - — - —
CVII. H — _ — _ —_ —_ _ _ — ~
OWANOIE Jat 1 4] _ — _ aad -- — _— =
CIX.H 4 18-21 1 10 1 9 = = = —
CX.H 3 12:5-17 — _— 1 5:5 _ — = =e
CXI. H 52 17-21 ge 16 1 10 —— — — =
Cx 12 10-20 2 15-17 1 6 _ — — =
CXC He 6 15-19-5 — _ = = = = = =
CXIV. H — — — — _ _ = — = =
CXV.H — — —_ _— _ _ _ _ — =
Continued.
Scophthalmus
norvegicus,
No. Size.
7 5-9
3 4-9
2 5-6
1 5-9
7 7-11
58 3:5-11
G7 3-7-6
10 5-7
il 4
3 6-8
2, 6-5
10 7-9
LARVAL AND POST-LARVAL TELEOSTEANS.
Gobius sp.
No. Size,
16 4-8:5
1 7
m. 4-9
2 Gas 7
51 =3-5-15
44 4-12
6 5-13
1 ll
vV.m. 4-8
vim 415
20 4-8
m. 47:3
$4 3-9
m. 5-12
2 ca. 13
60 8-26
8 4—7
m. 4-8
24 3-5-5
vim 414
6 3:7-13
9 3-6
120 3-11
3 3-4-5
15 2-8-6
4 5-5-7
10 3°7-5
a 4-6
2 6-8
3 5-7
7 6:5-11-5
10 10-11
il 9
9 4-5-7
11 3-7-8
2 2-6-6
52 3-5-10
62 2-7-9
4 6-8-5
! 4-5
1 7-5
2 7-8
5 7-8
7/ 8-13
1 7-5
2 9-13
4 7-8
2 4-8
3 4-8
17 7-16
Trigla sp.
No. Size.
1 6
3 6-7:3
i 7-5
1 5
4 4—10
3 7-10
2) 7-9:5
29 5-17
6 ca. 16
1 7-5
1 5:2
1 10
1 11
2 7-5-9
15 7-10
4 7-5-12
1 7 5)
Trachinus
vipera.
No. Size,
1 5
1 2-5
3 3-7-7
II 4
1 3
i 4-5
2 3-3-5-2
2 4-5
4 3-4
1 5
1 5
1 6-5
5 4-5
Callionymus
lyra.
No. Size.
6 2-7-2
3 2-8-6
m. 3-8
15 3-:2-6-5
m. 3-8
m. 3:5-10
2 3:°5-5
m. 3-9
vm. 3-9
3 4-5-8
4 2-4
0 3-8
v.m. 2:-5-?
5 2:8-7°5
2 4-6
21 2-5-8
20 2-2-4
1 3
2 3°8—5
2 3:3-7
1 5
iI 12
7 3:7
ee 4:7
3 4-5
5 5-8-5
19 3°7-7-5
Va 0—S
VAM 3:5—8
3 5-5-6
14 3-5-7-5
383
Blennius sp,
No.
1
| Boy
FES Mist term el s)) ee |]
pel a
|} e [wl] we
Size.
5
6-7-5
384 R. S. CLARK.
TABLE XXV.—.
Ctenolabrus
Clupea sp. Ammodytes sp, Labrus bergylta. rupestris. Arnoglossus sp.
No. of Haul. No. Size. No. Size. No. Size. No. Size. No. Size.
CXVI.H — — —_— — 1 11 = — — —
CXVII.H — — _ _ 1 7 — —_— — —
CXGVIEHIC REL at 7:5 26 7-17 _— _ a -- 2 13
CXIX. H — _ 1 9 6 4-7 — —_— _ —
CXX.H 60 9-22°5 1 8 _ — _— —_ 3 5:5-17-5
CXXI. H 30 8-23 8 7-26 i 4-5 — — +b 5-19-5
CXXII. H 36 12-16 21 7:2-29 1 5 — _ _ =
CXXIII.H — — _ - J 4 -— -- 1 3
CX FE 10 4 9-14 1 4 — _ 3 4-6°5
CXXV.H 3 17-20 8 11-22 1 3 _ — 4 5-6
CXXVI.H — = oo — 1 7 —_ —_ — _—
CXXVII.H 2 16-225 — a — _ = = — —
CXXVITI. H — — — — == = = = = =
CXXIX. H 1 7 2 5-7 - — — — — _—
CXXX.H 4 17 3 12-13 — — 1 ai _ =
CXXXI.H — - _ — — — = = z= =
CXXXII.H — — 1 Il — -- — _ _ =
lig AY ile 8-18 = _— = — _ = = —
Il. A m. 8-5-21:5 1 15-5 — — — — _ _
Til. A 263 12-20 2 14-5 — — _ — — oo
Iv. A — — 8 14-5-20-3 — _ — — — _—
V. A 48 7:25-20 7 14-23 — _ -- — 1 5:39
VIE VALO 12-22 — _ _ — = — — _
VII. A 17 138:5-17 — — — — — = = _
VIII. A 36 12-5—-20 1 15 1 7-6 — _— = _
IX. A 21 14-32:5 30 67-104 2 8-6-9 — _ — —
xX. A 13 Z — — 1 8-9 — — — =
XI. A 4 13-15 — — _— — — — — —
DVO Gs AN INe/ 11-18 _ — —_ _ — = — —
XIII. A 27 16-19 — oo — — — — _ —
XIV. A295 14-22 —_— — — _ — — — —
XV. A — — _ -- — _ = _— —_
OVA ACD 15-19-51 14 a — 1 7-14 _ —_-
VIL. A 5 10-19 _— — — — — — —
XVIII. A 42 18-25 1 31 8-75 — _ _
KIX. A 3 13°5-19. — — — _ 2 56-65 — _
XX AL 72 16 — a — _ 1 6-95 — =
XXI. A 2 411:5-16 — — 1 5:95 — _ _ _
XXII. A 19 9-5-20 _ — 2 55-65 — — — =
XXIII. A 10 11-18-5 1 15:5 — _ 1 9-8 4 6:4-7:12
XXIV. A 13 10-5-20 3 15-28 2° %-7-9-9 1 u —_ _
XXV. A — — _ = 3 8:26-9:-7 19 8-9-2 _ =
EXOXGV Ale AC el 12-5 2 6-8 3 Z 4 5:25-7 _— —
XXVIII. A — - — — — a -- — — =
XXVIII. A 7 11:5-18 2 11-5-14:5 1 Z — — _— —
KONO, PA EL 15 4 9-2-4 — — — _
XXX. A 1 26 — _ — — — — oa —
XXXI. A — oe = = 4 35-75 — — _ —
XXXIT A 6 417:-5-24 2 11-185 i 5D°5 1 9-38 — _
XXXIII. A 2 22-5 — _ 1 5:18 6 - 7:35-7:77 -— =
XXXIV. A 1 22 4 13-21 _ -- -- 2 79-23
XXXV.A 4 17-22 1 8.68 33 5.5-8 2 8-4 _
EXOXOXG VIE eAC ae Z, 1 13-5 8 5-5-7 1 8 _— =
XXXVIT. A 3 16-23 27 14-5-17-5 — — 16 5-7 3 §-12°5
XXXVITI. A 1 21 9 6-10 — _ 1 Z 1 6
XXXIX. A 2 10-21 26 7-14 36 4-5-7 29 5:5-9-5 1 11-5
XL. A — — - —_ a _ — — _ —
XLI. A 7 22:5-25 — _ 7. 6:25-7:22 2 7-28-9-11 — _
Oe Ae Z 5 9-15:5 7 3:9-6:3 5 17-28-95 —— -
AU NU 21 _— —_ _ _ — —_ -_— _
Continued.
Scophthalmus
norvegicus.
No. Size.
2 7-10
6 -10
2 5-67
9 6-3-9-64
ead
55 §-25-12-25
1 TI
8 4:5-7-7
9 5-5-8
1 9-8
9 7-35—-10-35
11 6-4-10
14 6-3-9-8
12 5-9
12 4-9-6-5
8 4-5-8-5
30 5-9-5
2 . 6-65-6-9
1 9-6
5 6-5-1]
2 6-58-8
1 8-5
LARVAL AND POST-LARVAL TELEOSTEANS.
Gobius sp. Trigla sp.
No, Size. No. Size.
7 4—6 — _-
D, ca. 9 — =
50 3-7-21 — _
— — 1 7:5
m. 4-25 6 7-11
2 5-10 1 4
23 3:7-13 1 7:5
a 5-6 = aot,
— — 1 7:98
— — 4 5-95-8
— — 9 6-2-11-9
— — 14 5-6—-11-27
_ - 1 8
— — 1 8-8-15
— — 1 9-8
1 10-8 — _
2 11-06-11-69 — _
10 8-15 — _
- = 1 Z
— -- 12 6-13-5
a 6 6-86—-10-5
1 6 5 10-17
— = 1 8-4
_ as il 14
= <= iI 10
2 4-6-4:75 — _
- os 1 9
19 7-15:5 2 8-5-15
— -— 3: 7-17
4 Z _ _
-- -- 1 7-2
Trachinus
vipera.
No, Size.
1 5
3 35-5
1 4
2 4-6
30 3-7
6 4-5
4 4-7
4 4-5
1 6
1 4
i 2-7
1 4-9
] 8:05
2 4-9
1 4
2 6:3
40 5-7°5
1 6-5
2 5-6—-6-6
Ca dces
7
Callionymus
lyra,
Size.
3:7-5
7°5
4-5-5
3-10
4-10
3-5
3-7
3-5
385
Blennius sp.
No. Size.
|
|
| nr | He dwe |
for)
or
386
No. Haul.
XLIV.
XLV.
XLVI.
XLVII.
XLVIII.
XLIX.
L.
LI.
eA:
IDO
LIV.
LV.
LVI.
LVII.
LVIII.
LIX.
IDSC
LXI.
LXII.
LXITI.
LXIV.
LXY.
LXVI.
LXVII.
LXVIII.
LXIX.
LXX.
LXXI.
LXXIT.
LXXITII.
LXXIV.
LXXYV.
LXXVI.
LXXVII.
LXXVIII.
LXXIX.
LXXX.
LXXXI.
LXXXII.
LXXXITI.
LXXXIV.
LXXXYV.
LXXXVI.
LXXXVII.
LXXXVIII.
LXXXIX.
XC.
XCI.
XCII.
xCUME
XCIV.
XCV.
X PEPE > PPPPESP PPE PEPE EpPEPEP PEE EPEE dd EEboebpepeeen
Clupea sp.
No. Size.
J 20
iL 23
I} 25
1 14
2 25
2 14-20
15 12-22
20 12-17
4 1J-16
4 13-5-16-5
17 9-5—211
1 36
1 11
1 24-5
1 23
1 Z
I 23
1 24-5
1 25
2 21-23
1 14
5 20-20:5
4 15-5-17
1 19-5
iy am CL ATER
TABLE XXV.—
Ctenolabrus
Ammodytes sp. lLabrus bergylta. rupestris. Arnoglossus sp.
No. Size. No. Size. No. Size. No. Size.
27 ca. 20 —_— — _ — 5 4-5-14:5
6 11-15 -- _ — — i 15
2 7-265 — — 7 45-65 22 4-5-14-5
1 a 20 3:47:55 2 75-8 — —
20 6:5-16-5 — — _ — 21 3-5-20°5
— — _ — - — 28 7-21-5
_— — — — _ — 5 6:5-12°5
1 a 1 5:5 1 6 — --
2 10-21 _ -- — — 7 4:5-23-5
8 6-5-1383 3 6-5-8 _— _ 25 4-15
3 7-16 — a oo — 33 4-14
— — _— — -— — 20 5-5-12
2 105-16 — —_ _— = 9 5-8-5
— — 1 5-49 = = 6 5-13°5
2 9-14 — — 2 5-5-6 14 7-21-5
1 b= 23754 5:25 1 6 31 4-5-14-5
12 4-5-12 il 5:2 — —_— 14. 5-5-17
6 6-165 — — —_ — 13 5-12
14 10-19 -- — — 2 5-7:5
113} 7-15 1 6-16 — _ 3 Z
1 14-5 _ _— — 1 8:5
= _ — — _ _ 4 9-19-5
1 7 - -- — — 7 6-5-10
2 13-175 — _ — = 4 5-15
_ _— 2 8 — ~ 2 6-6-5
_— — — — — _ 2 12-16
— — — — — — ] ll
2 85-10: — — 1 7-5 4 75-11
— —_— 1 — — 8 6-21
3 11-17 _ — _ —_ 5 8-18
5 6:5-21 — — — — 6 7-5-18
J 6 _ — _— _ 4 10-5-15
2 14 4 6-5-8 = = == =
— = = _ _ — 1 6
1 9 — _— _ — 1 20
1 6-5 = = = = — —
= = il 7 = bes =! =
12 10-5-10-5 — = — ~ 7 7:5-20
By 7-5-10 — — — a 2 13-5-20-5
1808-5148 = = = 2 2185
55 6-5-17 _— _ — _— 13 = 4-16-5
40k es oer ae. Se le ED
49 i265 155 te high ee ee ee mo Gig
3 9 = = = — 8 ca. 5
56 11:5-22 — _ 1 7 22 8-285
20 | (61650. = = f= =F GOH &
17 8-5-1655 — _— — — 12 4-5-20
32 7-18 os -- —— — 69 4-22
31 85-145 — _ _ — 13 4-19-5
LARVAL AND POST-LARVAL TELEOSTEANS.
Continued.
Scophthalmus
norvegicus. Gobius sp.
No. Size. No. Size.
-= _ 8 4-5-16-5
-= — 7 4-5-13
_ — nea Ls
pa = 1 3°5
—_ = 5 6-13
— = 1 10
= = 1 31
_ = 3 6-7
— — 1 7
_— -- 1 Z,
— ~~ 3 8-5-11
— — 2 3°5-4
_ _ 1 5-06
— — 1 4-02
— = 1 2-8
_ — 2 11-18
_— — 2 3-6
_ _— 2 9-12
— _ 1 6-5
_ — 2 6-8
_ — 1 6
= = 4 2-3-56
— _ 2 3-4
_ = 3
ca. 4-5
NEW SERIES.—VOL, X.
Trachinus
Trigla sp. vipera,
No. Size. No. Size.
-- ike 4-5-9
3 7-12 112 3-5-8
-- — 1 4:8
3) 7-0—N3°>: 17 3:b=5"5
1 9 — —
_ “= ] 4
— — 3 4:-5-6:°5
_ — 13 4-7-5
1] 7 10 4-7-5
1 8:5 4 3-5°5
— “= 2 4-5:5
2 9-16-5 5 4—6°5
-- — ] 18
— — P27 3°5-9
_ _ 25 3-11-25
— _ 4 3°75-5
1 4:69 3 4-4-5-1
— — i uf
_ — 2 3°6
— —- 1 5:4
_ _ 2 4-5-5-6
1 5:36 6 4:5-8-5
— _ 2 4:35
os _ 2 5:5-8:5
— — 3 Z
3 4-5-11 7 5-6
1 9:5 I 4-35
-- _ 1 13°5
6 7-10 — --
~- -- 4 6-7
] Z 2 4-9-5
1 8 1 5:5
Z 6-6-5 1 4
oo _— 1 6-5
a: a 1 4-4
~- — 4 5-10
it 8:5 — —
— 1 8
-- — 1 6-5
4 6:5-15 7 3-9
4 5:5-20 — --
i 10-5 1 5:5
2 5-16-5 4 ca. 4:5
4 7-5-13°5 1 Z
2 ca. 8 1 8-75
2 13-5-15:5 4 4-5-5
3 8-9 Lby/ 4-9-5
9 4:2-22 20 4-5
4 ca. 6 10 3:5-6
10 6-18 23 3-5-6-9
-- _ 3 2-68-5:2
NO. 2, JUNE, 1914.
Callionymus
lyra.
No. Size. ©
9 5-5-8
1 Ui
28 4-8-5
17 4-5-8
1 Z
5 3-8
29 3-11
8 4-7
4 3°5—-5
4 4-10
4 5-13
al 3:-7-4:6
13. 3-0—-6-7
10 2°-75-7-3
6 3-68—7-2
2, 5:3-6:7
3 3-6-6-7
1 5:5
1 4:5
5 3°8—-5:7
10. =5:6—-8°7
3 5:3-5:6
2; 4-6-5:5
3 4-6
1 6-03
3 5:2-8:8
1 6
1 6-5
1
1 7-5
4 4-5-8:5
10 3-6
11 4-5-9
29 3°5-8:5
4 4-5-7
1 4-8
11 3-8
8 3-7-5:6
18 4-5-4
1 5:3
387
Blennius sp.
No. Size.
4 5-6-7°5
1 8:5
3 5-5-8
1 Z
] 6
iL 4-5
2 ca. 6
1 10
i 7
2 5:5-7:°5
1 6-03
1 4:8
1 5:3
1 6:03
1 1
1 11
4 6-5-8
1 4
4 4-5-6°5
1 10
2 5-7
1 5:5
3 ca. 8
1 12-5
1 18-5
1 vi
2 9-13
3 5-6
3 4-5-5-5
2 5:2-6:7
1 5:2
7 4-10-5
218
388 R: 78,7 CLARK
TABLE XXV.—
Ctenolabrus
Clupea sp. Ammodytes sp. Labrus bergylta, rupestris. Arnoglossus sp.
No. of Haul. No. Size. No. Size. No. Size. No. Size. No. Size.
CIV. A 4 16:5-18:5 20 5-165 — _ — _ 7 4-5-18
CV. A 2 19-5-20 20 6-17 a — _ — 21 418-5
CV TE PAT a 20:5 6 11-5-18 — — — _ 14 5-21-5
CVII. A — = os = ue a2 = =I =
CVIII. A — == = es a soa ae ms 9 aril
CIX. A — _ — = = == = — 1 Z
CX. A — — = = _ = as SE Me =
CXI. A 1 9-5 — = ss — se = 4 5-75
CXII. A — — = at = . = = 2 =i
CXIII. A — = = = _ = = = 3 4-5-5
CXIV. A — — = = He = = ae 1 6
CXV. A — — ] 7 = as al = 4 4-5-10
CXVI. A — = ae a as ae us ES BO) ALG
CXVII. A — = os = ae = _ = 21 4-2]
CXVIII. A — — = a A = = = 13 4-19
CXIx. A — = =5 ee: _ i “als abe QAR AIC
CXxX. A — — == = == = = — 3 4:4-11°5
CXXI. A — — = a = = = _ 4 6-14:
CXXIT. A — — 1 5-5 = = — _ ll 5-7°5
CXXIII. A — _ = __ es = = a8 Qi Adie
CXXIV. A — — = = = a — — 25 4:8-9-5
OXEXYV. AN | 94-5=5°5 = = — — — 1 4
CXXVI. A — = = as oe ae = = 1 6
CXXVII. A — = = as = -_ ae = uz —_
OXSXeV Ae VAS 2 3:4 — = = BS = a <= =
CXXIX. A — “= a4 ee = = = at = =
CXXxX. A — = = = _ = = - pie a=
CXXXI. A — = = = ck me a me 6 4-5-8
CXXXII. A — = aes ae als me ee = 8 55-16
CXXXIITI. A — = = ae, = = = = 5 4-5-7
CXXXIV. A — — = = os = — - 20- 4-5-11
CXXXV. A — = = = = Zz = a i| 7-5
CXXXVI. A — = = oe = es = = 4 Aen
CXXXVII. A — = = = = ait = elt 2 4:8 6-5
CXXXVIII. A — = = = = ie = = is Gases
CXXXIX. A — — — = = — — — 10. 6-5-8
CXL. A — = = = = oo = — 7 5-9:75
CXLI. A — — — = = = — a Wil See
CXLII. A — = = = = = 2s = 93 4-5-10
CXLITI. A — — 1 6:5 — — oa — 4 4-25-6-25
CXUIVe A — = cs oo = = == = 8 6-8
CXLV. A — = ae - = ts ats == 3 5:36-5:67
CXLVI. A 2 5-5-6 — = = = -_ = = =
CWA ACL 5 = —_ = fe = = = =
CXLVIII. A 1 4-5 = a = ast = = ee pon
CUD, A PA lor — — = — - _ —
CL. A 4 5 = = = as = = = Es
CLI. A — — = = = = —_ = 1 6:25
CLIT. A 1 6-25 1 11-25 — _ ~ = 5 7-10
CLIT. A — = = a ae = = ] Z
CLIV. A — _ _ — — = — — 4 10-25-18
CUVEVAR 2a 52253 eee 20 -— — — — 10 9-5-17
CLVI. A 2 3:5-5 2 9-5-1055 — aaa -- — 49 4-5-18-5
CLVII. A 1 5:25 — = = = as = = =.
CLVIIT. A 16 4-12 = = = — — 3 3°5-31
CLIX. A 2 3°5-85 — = = = —_ == 9 8:-5_16-5
CLX. A — _ = ee Be ue a = 9 65-15
CLXI. A 3 4-5-6 _ a — — _ 6 ca, 3-16
CLXII. A 1 Z — — — — —_ — 7 Z
CLXIII. A 3 6-8-5 = — — — — - 3 Z
LARVAL AND POST-LARVAL TELEOSTEANS. 389
Continued,
Scophthalmus : Trachinus Callionymus
norvegicus, Gobius sp. Trigla sp. vipera. lyra. Blennius sp.
No. Size, No, Size, Size. No. Size. No. Size. No. Size.
_ 5-10 8 4-9 2 4-3-7 1 6:2
gy es =
#2 9
3:68-3-75 Z 4 3-5-10
es
|
|
= a = 8-5-14 a S ae
= = = Tl 4 Ls 22 ea =5
= = 9-24-5 = = =e 1s = =
es - 3-5 = = = = = xs
eS = a a3 = = = 1 6-5
22 = - 4 — = =
= = = = = = 1
= ae 5-6-5 = = 4 a
$1 = —9 =
= _ 4-5-7-5 1 7 Spel ge
= = ts of 25-6 s “3 =
|
moelrme|oarrme | | tll] | | omemrl] ole | erole |] ii i lore l tilt dtd dd | roe] He
=: cg a 6 ~ ee 7 oe:
— —_— — — — — -- 1
ae = ae el A au ox iy
Be = = Rime ee oe —_ ee ae
— — — 6-10-5 1 18 — — 4
_ — — 9-5 2 3:5-5:5 3 5:5 1
a a sce Sao) ee eb ty) Oy
ee = 651g. BS Sieg ge 1
ry he a i 1 z carly 1
= Ls a 6 = — 1 a _
=: a i CT Es 23 bd -
= = — 13 — — 1 5 1
= _ _ 5-25-7 1 4:25 — — 1
aes ec aa x na pe $3 Ss =
- — 4:25 55-11-51 Z _ — 1 8:5
= = = : ~ a as a a me
= = = 65-15 — — 2 Z — =
a 0, 22 = ae 9 = aa.
390 KR.) S.aCUAR Ke
TABLE :-XXV.—
Ctenolabrus
Clupea sp. Ammodytes sp. Labrus bergylta. rupestris. Arnoglossus sp,
No. of Haul. No. Size. No. Size. No. Size. No. Size. No. Size.
CLXIV. A 7 14-24 — — = = = = me a
CLXV. A — — _— — = = — == - ss
CLXVI. A 20 5-8 —_ = — = rss = ee med
CLXVII. A 2 5:25 _ — = oe — = 2 Zz
CLXVIII. A 38 7-5-8 — — = = = = ae ey
CLXIX. A 24 5-9 — = = = = 12 5-11
CUA 65-54 = = as ns we ex ? ie
CLXXI. A 38 6-15:5 1 17:5 _ — _ 145 5-20
CLXXII. A — — 2 19-24 = a — 2 Z
CLXXIII. A — — 1 12 _ — = - 17 =5-11°5
CLXXIV. A 9 7-16 1 12 _ = oe = 24 4-5-19
CLXXV. A 2 10-19 - — — — _ = 2 17-19
CLXXVI. A 12 5-9-5 ~ — _ — _ _ 57 = 4-13°5
CLXXVII. A 4 5-8-5 o= ~~ ~ — — -— 10 4-5-11-5
CLXXVIII. A- 7 6-11 — oa _ — = — +4 6-17
CLXXIX. A 5 7-5-8 — _ — _ _ — 24. 5-18
CLXXX. A 22 5:5-10 — — 1 4:5 — — 2 4:5
CHEROCRT PAWS TS Lah 5 == os = 2 as a 1 6
CLXXXII. A 3 6-10 1 22 — — — — a 9-5-18
CLXXXIII. A 12 105-12 — = = — — — 138 5-18-5
CLXXXIV. A 12 8-13 -—~ — — a =: = = =
CLXXXV. A 8 4.5-10.5 — — — = = = = oe
CLXXXVI. A 14 3-5-11 — — — = -- — 1 a
CLXXXVII. A 4 7-10 _ = — = = = = pad
CLXXXVIII. A 17 5-12 — _— — =a = = = cat
CLXXXIX. A 26 6-18 — — = — = = — =
CXC. A 17 7:5-17 — — — — _ -- 1 Z
CXCI. A 9 8:5-12:'5 — — cs = == a ems pe
CXCII. A 228 5:5-24 — — — = == ~ = ae
CXCIII. A 44 8-15:25 — — — = = = = =i
CXCIV. A 102 7-25-18:5 — — — = = == = ee
CXCV. A 3 5-10-5 — _ = = = = = ait
CXCVI. A 2 7-195 — _ = == = = Ee es
CXCVII. A’ 37 7-16 — — = = ae ae ae =
CXCVIII. A 17 75-21 — — = = = oe As aoe
CXCIX. A 22 5-5-19 — — = = = = a =
CC. A 4 11-16 — — — = == == a pe
CCI. A 2 10-11 — — — = = = = a
CCII. A 3 8-13 — — _ — — —_ — =
CCITT AY 3 11-13 _ — = = = aa bas =
CCIV. A 4 10:5-12:5 — a — — — = == a
CCV. A 1 is _ — — — — — — =
LARVAL AND POST-LARVAL TELEOSTEANS. 391
Continued.
Scophthalmus Trachinus Callionymus
norvegicus, Gobius sp. Trigla sp. vipera. lyra. Blennius sp.
No. Size. No. Size. No. Size. No. Size. No. Size. No. Size.
= = = — — _ 1 1 —- — 1 21
— — 1 19 -— — — a a _— _ _
_ = l 6 2 6:°5-7°5 1 5:5 — _ _— —_
= = Eis en ae = 1 7 ane Ad fe =
22 Er ms a. 1 Zz aA) —_ = as = —
= — — —_ _ oo 1 5 ul 5 — _—
as #5 cae ae == a = ‘2 1 7 a8 Eu
— — _ _ 2 8—28°5 4 Z 11 6-9-5 5 6-5-8
— - _ — 2 ca 18 4 5-6:5 _ _ = =
_ _ _— _ 5 5-13 1 6 — a 1 7
= — 1 6 3 5-12 3 5-7-5 6 4-5-10 6 6:5-12
— -- _ —~ 1 14 1 9 _ — — _
— =: 1 5:5 — — 1 7-5 2 6-8 — —
_— — _ — 1 7-5 3 5:5-7 i 8 — _
_ _- _ — 2 6-8 1 7 1 7:5 _ =
— — 33 8-10 3 5-7 4 5-7 6 5:8 — _
— = — _— oy tb 14-5 8 — -- 1 13
— — — _— 8 7-5-1255 — —_ — — —_
hs = 1 6 = 2 By = ox — = av
_ -- — — — — -- — 1 5-02 _ _
oe — 27 11-29 _ — _ _ _ _ = =
= = Up ESS SS = = = = = = =
392 R. S. CLARK.
CONCLUDING REMARKS.
The Tables of the occurrence of the various species with the number
and size of individuals show that all those recorded spawn either in the
immediate neighbourhood or at localities not far distant.
It may be of interest to note here the capture of the young stages of
those adult forms which have approximately their most northern limit
of distribution in Plymouth waters.*
The spawning period is definite for most of the species, though in
cases such as the sprat and dragonet, it is prolonged indefinitely over a
considerable part of the year. In closely related species of the same
genus there may be wide variation in the length and time of spawning.
One of the most interesting problems suggested by the study of the
distribution of pelagic larval and post-larval forms is the question
of the nature of the causes which bring about the movements of
young fishes from the inshore to the offshore waters and vice versa.
There appears to be evidence in favour of the view that in some localities
these movements are the result of inshore and offshore currents which are
not constant and which seem to vary according to the prevailing winds,
In narrow waters like the English Channel, the currents are doubtless
modified by the general set of the main currents from the Atlantic, and
by the contour of the coast-line. In addition, the tidal streams tend to
make conditions more complex. The present records bring some evidence
to bear on the matter. For example, pelagic larval and post-larval
forms of Ctenolabrus rupestris, an inshore spawner, occurred in the waters
south of the Eddystone rocks, while similar stages of Solea variegata, a
deeper water type, were taken in comparatively shallow areas. The whole
question is one of great interest and might well repay further vestigation ,
The vertical distribution of the young was found to vary considerably
during day and night hauls. The latter yielded a much larger per-
centage of young forms from the surface layers.
Finally, incompleteness in the study of the Clupeide, Ammodytide,
Trigide, Bothine, Gobuide, and Bleniide must be acknowledged, but
these are now receiving special attention.
REFERENCES.
Ehrenbaum’s two volumes on “ Kier und Larven von Fischen”’ in the
Nordisches Plankton series, Lief 4, 1905, and Lief 10, 1909, have been used
extensively in the present work, both for the description of species and in
the references to papers published previous to 1909.
* Since this paper went to press, the larve and post-larve of Serranus cabrilla have
been identified from the 1913 material. I am indebted to Prof. Ehrenbaum for
confirmation of my identification.
LARVAL AND POST-LARVAL TELEOSTEANS. 393
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Rapp. et Proc. Verb. XII. 1910.
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la Mer de Nice (parages de Monaco) et du Golfe de Lion.
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Fischeier.
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394 R. S. CLARK.
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Repeke, H. C. Bericht iiber die Hollindischen Arbeiten zur Natur-
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Rapp. en Verhand. Rijksinst. v. Visscherijonderzoek. Deel I, Afl. 1.
1913.
Wottaston, H. J. Bucnanan. Report on the Results of the Fish-Egg
Cruise made by the 8.8. Hualey in June, 1909. Internat. Fish.
Investigations. Marine Biol. Assoc. Report III, 1906-8 (Cd. 5546).
1911:
Teel
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oO
Or
—
Marine Biological Association of the
United Kingdom.
Report of the Council, 1913.
The Council and Officers.
Four ordinary meetings of the Council were held during the year,
at which the average attendance was 11. A Committee of the Council
visited and inspected the Plymouth Laboratory.
The Council has to record with regret the death of three of its
Vice-Presidents, Lord Avebury and Dr. A Giinther, who had been
connected with the Association since its foundation, and Sir John
Murray, as well as that of Professor Adam Sedgwick and of Dr. P. L.
Sclater, who were both members of the original Council and always
took a deep interest in the Association.
The thanks of the Association are due to the Royal Society and to
the Linnean Society, in whose rooms the meetings of the Council have
been held.
The Plymouth Laboratory.
No important repairs to the building were necessary during the
year. As regards the machinery, the small gas-engine which is used
for circulating sea-water through the tanks has been fitted with a new
piston and cylinder liner, and the arrangements for cooling the engine
have been altered. The pumps will soon require some attention, but
in other respects the machinery is in an efficient condition. The
circulation of sea-water through the tanks has been maintained
without any interruption.
The Boats.
The Oithona was put in commission in May, and has been working
continuously since that time. Mr. E. T. Browne having undertaken to
use the vessel in connection with his work on hydroids and medusz
and to pay her expenses during a portion of the winter, the Council
has been able to keep the vessel in commission throughout the whole
year. This has been a very great advantage in many ways, especially
396 REPORT OF THE COUNCIL.
as it has prevented the usual disbanding of the crew for the winter
months.
A new sailing-boat has been built to replace the old Anton Dohrn,
which had done good service for many years. The new boat is a fine
sea-boat and well suited for her work.
The small motor-boat given to the Laboratory by Colonel Giles was
used during the summer, but she has not proved quite a suitable type
of boat for rough work. It is proposed to sell her and replace her by
a motor-boat better adapted for dredging and trawling.
The Staff.
The staff remains as last year, with the addition of Mr. E. Ford as
Assistant Naturalist. Mr. E. W. Nelson, who left the Laboratory to
take part in Captain Scott’s Antarctic expedition, has returned to work
out the material collected there, and has been made an honorary
member of the staff. Mr. Matthews and Mr. Crawshay have spent the
greater part of the year in connection with the expedition of the
Scotia, which was sent out to study the movements of the ice off the
Labrador coast. They both took part in the actual expedition,
Mr. Matthews being chief of the scientific staff, and they have since
been engaged in working up the results of the hydrographical and
plankton observations which were made on board. The expedition was
organized by the Board of Trade and the principal steamship companies
running on the North Atlantic routes, by whom all the expenses
were paid.
Occupation of Tables.
The following Naturalists have occupied tables at the Plymouth
Laboratory during the year :—
E. Aunap, Russia (Elasmobranchs).
E. T. BRowNnk, B.A., Berkhamsted (Hydrozoa).
Prof. E. L. Bouvimr, Paris (Crustacea).
A. Bowman, D.sc., Edinburgh (Fishes).
G. E. Buuien, St. Albans (Plankton).
J. W. CHALONER, Burnley (Fishes).
W. DE Morean, Plymouth (Protozoa).
F, Martin Duncan, Twickenham (Photography of Marine Animals).
J. Gray, Cambridge (Electrical Conductivity of Echinus Eggs).
W. O. R. Kine, Leeds (Echinus).
Miss D. Jonpaw Luoyp, Cambridge (Regeneration).
D. C. McIntosq, pD.sc., Edinburgh (Echinoderms).
Prof. J. McMurricu, Toronto (Anemones).
Mrs. MatrHews, Plymouth (Aleyonium).
G. R. Mtngs, m.a., Cambridge (Heart Rhythm).
REPORT OF THE COUNCIL. 397
Dr. Ta. MortENSEN, Copenhagen (Echinoderms).
E. W. Netson, Plymouth (Antarctic Plankton).
F. A. Porrs, Cambridge (Polychietes).
L. N. G. Ramsay, Cambridge (Nereids).
R. W. H. Row, London (Sponges).
J. T. SAunpers, Cambridge (Alkalinity of Fresh-water and Sea-water).
R. E. Savage, London (Fishes).
Mrs. E. W. Sexton, Plymouth (Amphipoda)._
Prof. H. D. Senror, New York (Nervous System of Elasmobranchs).
C. SHEARER, M.A., Cambridge (Echinus).
GEOFFREY SMITH, M.A., Oxford (Crustacea).
Capt. F. H. Stewart, Lahore (Nematodes).
Dr. Nizs Svepetius, Upsala (Nitophyllum),
Miss A. W. THomson, Oxford (Nicothée).
Dr. Stuart THomson, Manchester (Brain of Selachians).
H. C. THornton, Oxford (Hzemosporidia).
A. W. Waters, Bournemouth (Polyzoa).
The usual Easter Vacation Course in Marine Biology was conducted
this year by Mr. F. A. Potts, M.A., and was attended by twenty-one
students. Mr. J. T. Cunningham, M.A., brought a class of five students
from the South-Western Polytechnic, Chelsea, at Whitsuntide.
General Work at the Plymouth Laboratory.
Considerable progress has been made with the different researches
upon which the scientific staff has been employed. A number of
reports upon this work were published in the Journal (Volume X,
No. 1) issued during the year, and still further reports are now in the
press and will be published immediately.
Mr. k. 8S. Clark, who is carrying out investigations on fishes and
fishery questions, was engaged during the early part of the year in
studying the spring mackerel fishery carried on off the west coast of
Cornwall. The season was in some ways unfortunate, as the fishery
was for the most part abnormally bad. Nevertheless observations
made during such a season are not without value, since they yield use-
ful material for comparison with years when the fish are abundant.
By examining the stomach contents of fishes caught with lines and
trawls, Mr. Clark was successful in obtaining evidence of the presence
of mackerel near the bottom in places where the fishermen were unable
to capture any at the surface.
After the Oithona was put in commission in May, Mr. Clark devoted
his time to the collection of larval, post-larval and young stages
of fishes occurring in the neighbourhood of Plymouth. These were
captured by means of the Petersen young-fish trawl and with large
tow-nets, and a very extensive collection was made. The collection has
398 REPORT OF THE COUNCIL.
since been studied and a detailed report upon it, including a number of
illustrations of different stages in the life-histories of the fishes, is in
the press.
Mr. Orton has continued to study the modes of feeding and the rate
of growth of invertebrates. The growth rate of many species has
been determined by fixing in convenient positions in Plymouth Sound
various objects, such as shells, tiles and pieces of wood, and measuring
the growth of the different animals which attach themselves to these
objects. Similar measurements have been made of animals growing on
marked objects put on the bottom in the Sound and subsequently
dredged up. The growth of many of these fixed species has been
shown to be surprisingly rapid, and frequently several generations may
be produced in the course of a year. A preliminary report on the
subject is in the press.
The Director has continued his experiments upon the growth of
plankton diatoms under laboratory conditions, which have been referred
to in previous reports, and a paper on the subject is in course of
preparation. The Director has also been continuing his studies of the
marine annelids of the Plymouth area, and a number of new records
have been added to the local fauna.
The trustees of the “Ray Lankester Fund,” established by Mr.
G. P. Bidder, elected Professor E. L. Bouvier of the Natural History
Museum at Paris as the first “Ray Lankester Investigator.” Prof.
Bouvier arrived at the Laboratory in July and remained until the end
of August, the special object of his work being to study the life-
history of the sea-crayfish (Palinurus vulgaris). One of the most
interesting stages in the later larval development of this animal, the
puerulus, which was known to occur in many foreign species of the
genus Palinurus, had never been observed in the case of the common
European form. This, as well as nearly all the earlier stages, was
obtained by pelagic fishing with the young-fish trawl in the neigh-
bourhood of the Eddystone. Prof. Bouvier also obtained specimens
of the interesting crustacean larva Trachelifer, which had not pre-
viously been recorded from the English Channel.
Dr. Mortensen, of Copenhagen, worked during the summer at the
development of Echinederms, and has published a paper in the Journal
of the Association containing descriptions of a number of larve
belonging to this group, which he had obtained by fertilizing the eggs
and rearing the larval stages in the Laboratory.
Some interesting experimental work on the electrical conductivity of
Echinus eggs was carried out by Mr. J. Gray, and a preliminary
account of his experiments has been published in the Journal.
REPORT OF THE COUNCIL. 399
Dr. C. Shearer has continued his work on the hybridization of dif-
ferent species of Echinus, and during the year a detailed memoir
containing an account of the previous work on this subject carried out
by Dr. Shearer, Mr. De Morgan, and Mr. Fuchs, has been published in
the Philosophical Transactions of the Royal Society.
Mrs. Matthews has continued her work on the development of
Alcyonium, and has succeeded in obtaining and studying all stages in
the development of this form.
Mr. W. De Morgan has been studying the protozoan fauna of
Plymouth, especially the ciliates found in the Laboratory tanks.
Dr. Stuart Thomson spent three months at the Laboratory during
the summer, which he devoted to researches on the anatomy of the
brain of Elasmobranchs.
The Library.
The thanks of the Association are due for the following books and
current numbers of periodicals presented to the Library during the
year :—
Académie Imp. des Sciences de St. Pétersbourg. Bulletin.
Academy of Natural Sciences, Philadelphia. Journal.
American Microscopical Society. Transactions.
American Philosophical Society. Proceedings.
American Museum of Natural History. Annual Report.
Bulletin.
Memoirs.
Armstrong College. Calendar.
Arendals Fiskeriselskab Beretning.
Australian Museum. Records.
Report.
Bergens Museum, Aarbok.
Aarsberetning.
An Account of the Crustacea of Norway, etc. By G, O. Sars.
Bernice Pauahi Bishop Museum, Honolulu. Occasional Papers.
Fauna Hawaiiensis.
Board of Agriculture and Fisheries. Bye-laws under the Sea Fisheries Regu-
lation Acts, 1888 to 1894, in force on the 1st February, 1913.
—— Annual Report of Proceedings under the Salmon and Fresh-water
Fisheries Acts.
—— Monthly Return of Sea Fisheries, England and Wales.
Report of Proceedings of Annual Meeting.
Biochemical Bulletin.
British Association for the Advancement of Science. Report.
British Museum (Natural History). Catalogue of the Library.
Special Guide No. 6. Flight Exhibition.
Bulletin Scientifique de la France et de Ja Belgique.
400 REPORT OF THE COUNCIL.
Bureau of Productive Industry, Formosa. Icones Plantarum Formosanarum.
Bureau of Science, Philippine Islands. Journal of Science.
California Academy of Sciences. Proceedings.
Cardiff Library. Report.
Carnegie Institution of Washington: Department of Experimental Evolution.
Annual Report.
Department of Marine Biology. Report.
Club Montanyenc, Barcelona. Butlleti,
College of Agriculture, Tokyo. Journal.
College of Science, Tokyo. Journal.
Colombo Museum. Report.
—— Spolia Zeylanica.
R. Comitato Talassografico Italiano. Bollettino.
—— Memoria.
Comité du Laboratoire de Carlsberg. Comptes Rendus.
Report on the Danish Oceanographical Expeditions 1908-10 to the
Mediterranean and Adjacent Seas.
Conchological Society of Great Britain and Ireland. Journal of Conchology.
Connecticut Academy of Arts and Sciences. Transactions. —
Conseil perm. internat. pour Exploration de la Mer. Bulletin Statistique.
—— Publications de Circonstance.
—— Rapports et Proces-Verbaux des Réunions.
—— Investigations on the Plaice. General Report I. Plaice Fishery and Pro-
tective Measures. Preliminary Brief Summary of the most important
points of the Report. By F. Heincke,
— — Mémoire sur les Travaux du Conseil pendant les années 1902-12.
Cornwall Sea Fisheries Committee. Reports.
Cuerpo de Ingenieros de Minas del Peru. Boletin.
Dept. of Agriculture, etc., Ireland. Report.
—— Scientific Investigations.
Dept. of Commerce and Labor, Bureau of Fisheries, U.S.A. Bulletin.
—— Pamphlets.
Dept. of Marine and Fisheries, Canada. Dominion Shell-Fish Fishery Com-
mission.
—— The Canadian Oyster. Its Development, Environment and Culture. By
J. Stafford.
—— Contributions to Canadian Biology.
Deutscher Fischerei-Verein. Zeitschrift fiir Fischerei.
Deutscher Seefischerei-Verein. Mitteilungen.
Dominion Museum. Bulletin.
Dove Marine Laboratory. Report.
Falmouth Observatory. Meteorological and Magnetic Reports.
La Feuille des Jeunes Naturalistes.
Field Museum of Natural History. Publications.
Finnlindische Hydrographisch-Biologische Untersuchungen. Abhandlungen.
—— Hydrografisk-Biologiska Hafsundersokningarna under ar 1911. By R.
Witting.
Fischzuchtanstalt Nikolsk. Aus der Fischzuchtanstalt, Nikolsk.
Fisheries Society of Japan. Journal.
The Fisherman’s Nautical Almanac. By O. F. Olsen.
REPORT OF THE COUNCIL. 401
Fishery Board of Scotland, Annual Report.
Salmon Fisheries.
—— Scientific Investigations.
—— Reports (Northern Area) on Fishery and Hydrographical Investigations
in the North Sea and Adjacent Waters.
Fiskeri-Beretning.
Government Museum, Madras. Report.
Guernsey Society of Natural Science. Report and Transactions.
Illinois State Laboratory of Natural History. Bulletin.
Imperial Bureau of Fisheries, Japan. Report.
Indian Museum. Memoirs.
—— Records.
—— Report.
Institut Océanographique. Annales.
Institut de Zoologie, Montpellier. Travaux.
R. Irish Academy. Proceedings.
Kansas University. Science Bulletin.
Kommission zur wissenschaftlichen Untersuchung der Deutschen Meere, etc.
Wissenschaftliche Meeresuntersuchungen.
Kommissionen fiir Havunderségelser, Copenhagen. Meddelelser.
K. Bayerischen Akademie der Wissenschaften, Miinchen. Abhandlungen.
—— Sitzungsberichte.
Kgl. Danske Videnskabernes Selskab. Oversigt.
—— Skrifter.
Kgl. Norske Videnskabers Selskabs Skrifter.
Laboratoire Biologique de St. Pétersbourg. Bulletin,
Lancashire Sea Fisheries Laboratory. Report.
Lancashire and Western Sea Fisheries. Superintendent’s Report.
Leland Stanford Junior University. Publications.
Dudley Memorial Volume.
Linnean Society. Transactions.
Liverpool Biological Society. Proceedings and Transactions.
Louisiana State Museum. Report.
Lunds Universitets Arsskrift.
Manchester Microscopical Society. Annual Report and Transactions.
Marine Biological Association of the West of Scotland. Report.
Marine Biological Laboratory, Woods Hole. Biological Bulletin.
Marine Department, New Zealand. Report.
Mededeelingen over Visscherij.
Meteorological Office. Monthly Pilot Charts.
Annual Report of the Committee.
R. Microscopical Society. Journal.
Ministére de l’Instruction publique, France. Deuxieme Expédition Antarctique
Frangaise (1908-1910).
Miramichi Natural History Association. Proceedings.
Musée du Congo Belge. Annales.
Museo de la Plata. Revista.
Musée Océanographique de Monaco, Bulletin.
Museo Nacional, Buenos Aires. Anales.
Museum of Comparative Zoology, Harvard College. Bulletin.
402 REPORT OF THE COUNCIL.
Museum of Comparative Zoology, Harvard College. Memoirs.
Muséum National d’Histoire Naturelle, Paris. Bulletin.
The Museums Journal.
Natural History Society of New Brunswick. Bulletin.
Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne.
Transactions.
Naturforschende Gesellschaft in Basel. Verhandlungen.
Naturhistorischen Museum, Hamburg. Mitteilungen.
Naturhistoriske Forening, Copenhagen. Videnskabelige Meddelelser.
Nederlandsche Dierkundige Vereeniging. ‘Tijdschrift.
—— Verslag Aanwinsten der Bibliotheek.
New York Academy of Sciences. Annals.
New York Zoological Society. Bulletin.
Report.
New Zealand Institute. Transactions and Proceedings.
Norges Fiskeristyrelse. Aarsberetning vedkommende Norges Fiskerier.
La Nuova Notarisia.
Oberlin College. The Wilson Bulletin.
Osterreichische Botanische Zeitschrift.
Physiographiske Forening, Christiania. Nyt Magazin for Naturvidenskaberne.
Plymouth Meteorological Report.
Quarterly Journal of Microscopical Science. (Presented by Sir E. Ray
Lankester, K.C.B., F.R.S.)
Rijksinstituut voor Visscherijonderzoek. Rapporten en Verhandelingen.
Rothamsted Experimental Station. Report.
Royal Society of Edinburgh. Proceedings.
—— Transactions.
Royal Society of London. Philosophical Transactions.
Proceedings.
Royal Society of Tasmania. Papers and Proceedings.
Royal Society of Victoria. Proceedings.
Selskabet for de Norske Fiskeriers Fremme. Norsk Fiskeritidende.
Senckenbergische Naturforschende Gesellschaft, Frankfort. Bericht.
Smithsonian Institution. Report on the Library.
—— Smithsonian Miscellaneous Collections.
—— Descriptions of Three Species of Sand Fleas (Amphipods) collected at
# Newport, Rhode Island. By 8. D. Judd.
—— New Marine Worms of the Genus Myzostoma. By J. F. McClendon.
Societa di Naturalisti, Napoli. Bollettino. -
Societas pro Fauna et Flora Fennica. Acta.
—— Meddelanden.
Société Belge de Géologie, etc. Bulletin.
Société Centrale d’Aquiculture et de Péche. Bulletin.
Société Enseignement des Péches Maritimes. Bulletin Trimestriel.
Société de Géographie de Finlande. - Fennia.
—— But et Méthodes de la Geographie Scientifique. By J. J. Sederholm.
Société Imp. Russe de Pisciculture et de Péche. Vyestnik R‘ibopom‘shlen-
nosti.
Société Zoologique de France. Bulletin.
—— Memoires.
REPORT OF THE COUNCIL. 403
South African Museum, Annals.
Svenska Hydrografisk-Biologiska Kommissionen. Skrifter.
Kgl. Svenska Vetenskaps-Akademien. Arkiv for Botanik.
—— Arkiv for Zoologie.
—— Handlingar.
Syracuse University. Contributions from the Zoological Laboratory.
Tohoku Imperial University, Japan. Science Reports,
Torquay Natural History Society. Journal,
Transvaal Museum. Annals.
Unione Zoologica Italiana. Rendiconto.
United States National Herbarium. Contributions.
United States National Museum. Bulletin.
—— Proceedings.
R. Universita di Napoli. Istituto di Anatomia comparata. Studii sui rapporti
fra Differenziazione e Rigenerazione, I. By P. Della Valle.
—— Die Morphologie des Zellkerns und die Physik der Kolloide. By P.
Della Valle.
—— Oligognathus parasiticus n. sp. endoparassita dello Spio mecznikowianus.
Clprd. By A. Cerruti.
—— Intorno al nucleo vitellino de Comatule. By A. De Gasparis.
—— Osservazioni intorno alla struttura del Guscio delle uova degli ofidi. By
T. Guida.
—— Sulle forme che assume il nucleo vitellino delle Asterie e di alcuni ragni.
By G. Jatta.
—— Contributo allo studio di aleuni organi dell’ apparecchio genitale maschile
nelle specie nostrane del genere Lacerta. By A. Morgera.
—— La relazione tra il testicolo ed il deferente di alcuni Rettili. By A.
Morgera.
-—— Ricerche sulla glandola ed il canale di Leydig nei machi di Scyllium. By
A. Morgera.
—— Contributo alla embriogenesi degli organi compresi tra il testicolo e il
deferente nella Cavia cobaya. By A. Morgera.
—— Le prime fasi dello sviluppo dell’ Aplysia. By L. Manfredi.
—— Studii sullo sviluppo della Chromodoris elegans. By F. Rho.
—— Lorgano di Rosenmiiller nella Cavia cobaya. By G. Sacchetti.
University of California. Publications. Zoology, Physiology, Botany.
University College, Aberystwyth. Report on Investigations towards the din- ,
provement of Fisheries in Cardigan Bay and its Rivers.
University of Manchester. Change in the name of a genus of Alcyonaria.
By 8. J. Hickson.
—— Observations on the Coloration of Echinus angulosus, A. Agass. By
J. S. Thomson.
Notes on some Stylasterina in the Museum d’Histoire Naturelle de Paris.
By 8. J. Hickson.
—— On Gypsina plana, Carter, and the Relations of the Genus. By
M. Lindsey.
—— The Scientific Results of the Salmon Scale Research at Manchester
University. By P. C. Esdaile.
—— A Report on the Extra-Antarctic Amphipoda Hyperiidea, collected by
the Discovery. By D. A. Stewart.
NEW SERIES.—VOL. X. NO. 2. JUNE, 1914. 2c
404
REPORT OF THE COUNCIL.
University of Pennsylvania. Contributions from the Zoological Laboratory.
University of Sydney. Reprints of Papers from the Science Laboratory.
University of Toronto. Studies.
Kgl. Vetenskaps Societeten, Upsala. Nova Acta.
Visscherij-Station, Batavia. Mededeelingen.
Visschershaven, Ijmuiden. Jaarsverslag.
Wistar Institute of Anatomy and Biology, Philadelphia. Reprints.
Zoological Laboratory, Cambridge. Cytological Observations on the Early
ee of Segmentation of Echinus Hybrids. By L. Doncaster and
. Gray.
—— The Effects of Hypertonic Solutions upon the Fertilized Eggs of Echinus.
By J. Gray.
—— On Methods of Producing Artificial Parthenogenesis in Echinus esculentus,
and the rearing of the Parthenogenetic Plutei through metamorphosis. By
C. Shearer and D. J. Lloyd.
—— Herpyllobinus arcticus. By K. Haddon.
—— Report of the Committee appointed to investigate the Biological Problems
incidental to the Belmullet Whaling Station.
—— The Inheritance of the Aboral Process of the Echinocardium-Pluteus.
By H. M. Fuchs.
—— Stolon Formation in Certain Species of Trypanosyllis, By F. A. Potts.
—— Mycetomorpha, a new Rhizocephalan (with a note on the sexual condition
of Sylon). By F, A. Potts.
Zoological Museum, Copenhagen. The Danish Ingolf-Expedition.
Zoological Society of Japan. Annotationes Zoologicee Japonenses.
Zoological Society of London. Proceedings.
—— Transactions.
— — Year Book.
Zoologische Sammlung des Bayerischen Staates. Beitriige zur Naturgeschichte
Ostasiens.
Zoologisches Museum, Berlin. Bericht.
—— Mitteilungen.
Zoologiska Institution, Upsala. Zoologiska Bidrag fran Uppsala.
Director, Royal Gardens, Kew. Nouvelles Archives du Muséum d’Histoire
Naturelle.
G. Drew, Esq. A number of books and pamphlets from the library of the late
G. Harold Drew.
Prof, Dr. E. Ehrenbaum. Der Fischerbote.
Colonel G. M. Giles. Meteorological Record.
Quarterly Journal of the Royal Meteorological Society.
—— A number of Charts and Maps.
Prof. Herdman, F.r.s. The Nutrition and Metabolism of Marine Animals in
Relationship to (#) Dissolved Organic Matter and (6) Particulate Organic
Matter of Sea-water. By B. Moore, E. S. Edie, E. Whitley and
W. J. Dakin.
De Hoofdinspecteur der Visscherijen, ’s-Gravenhage. Jaarverslag. der
Visscherijinspectie.
Dr, H. R. Mill. Symons’s Meteorological Magazine.
REPORT OF THE COUNCIL. 405
To the authors of the Memoirs mentioned below the thanks of the
Association are due for separate copies of their works presented to
the Library :—
Agassiz, G. R. Letters and Recollections of Alexander Agassiz.
Allen, W. F. Notes on the Breeding Season and Young of Polyodon Bey
Studies on the Development of the Veno-Lymphatics in the Tail-Region ~
of Polistrotrema (Bdellostoma stoutt).
Aunap, A. Uber die Chondriosomen der Gonocyten bei Knochenfischen,
Blegvad, H. Some small Leptocephalids from the Atlantic.
Bond, C. J. On Heterochromia iridis in Man and Animals from the Genetic
Point of View.
Bonnesen, E. P., Boggild, O.B., and Ravn, J, P. J. Carlsbergfondets Dybde-
boring.
Bouvier, E. L. Sur les genres Pseudibacus et Nisto, et le stade natant des
Crustacés decapodés-macroures de la famille des Scyllaridés.
Breitfuss, L. L. Zur Kenntnis der Spongio-Fauna des Kola-Fjords.
Buddenbrock, W. v. Uber die Funktion der Statocysten im Sande grabender
Meerestiere (Arenicola und Synapta).
—— Untersuchungen iiber die Schwimmbewegungen und die Statocysten der
Gattung Pecten.
Clark, A. H. The Crinoids of the Indian Ocean.
Clark, R. 8. Scottish National Antarctic Expedition. Scotia Collection of
Fishes from St. Helena.
Cligny, A. Sardines et Pseudo-Sardines. Contribution a VHistoire de la
Péche et de l’Industrie Sardiniere.
Dale, D., and Mines, G. R. The Influence of Nerve Stimulation on the Electro-
cardiogram.
Danois, E. le. Contribution a Etude Systématique et Biologique des Poissons
de la Manche occidentale.
Dantan, R. La fécondité de l’Cstrea edulis (L.).
Dendy, A. Report on the Calcareous Sponges collected by H.M.S. Sealark in
the Indian Ocean.
By-Products of Organic Evolution.
Dendy, A., and Row, R. W. H. The Classification and Phylogeny of the
Calcareous Sponges, with a reference list of all the described Species,
systematically arranged.
Dobell, C. C. The Principles of Protistology.
—— On some Parasitic Protozoa from Ceylon,
—— Paraspirillum vejdovskii n, g., n. sp., a new bacterial form.
—— On Cristispira veneris nov. spec., and the Affinities and Classification of
Spirochaets,
Researches on the Spirochaets and Related Organisms,
—— On the Systematic Position of the Spirochaets.
—— Contributions to the Cytology of the Bacteria.
—— Some Recent Work on Mutation in Micro-Organisms.
—— Contributions to the Life-history of Hemocystidium simondi Castellani et
Willey.
Dunkerly, J. 8. Flagellata and Ciliata.
406
REPORT OF THE COUNCIL.
Ehrenbaum, E. Uber Altersbestimmungen am Aal.
—— Uber die Flunder (Pleuronectes flesus L.).
—— Report on the Mackerel.
Ehrenbaum, E., and Marukawa, E. Uber Altersbestimmung und Wachstum
beim Aal.
Farran, G. P. Plankton from Christmas Island, Indian Ocean. II.
Fauvel, P. Quatrieme note preliminaire sur les Polychetes provenant des
campagnes de |’ Hirondelle et de la Princesse-Alice, ou deposées dans le
Musée Océanographique de Monaco.
—— Campagne du Pourquoi-Pas? (Islande et Jan Mayen, 1912). Annélides
Polychétes,
Fuchs, H. M. The Inheritance of the Aboral Process of the Echinocardium
Pluteus.
Fujioka, M. Studien iiber den anatomischen Bau des Holzes der japanischen
Nadelbaume.
Goodrich, E.S. On the segmental Structure of the Motor Nerve-plexus.
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On the Culture of the Plankton Diatom /halassiosira
gravida Cleve, in Artificial Sea-water.
By
E. J. Allen, D.Sc., F.B.S.,
Director of the Plymouth Laboratory.
In a former paper,* written in conjunction with my colleague Mr. EK. W.
Nelson, the conditions under which a rapid and continuous growth of
marine plankton diatoms can be obtained in laboratory cultures were
discussed. It was pointed out that when natural sea-water is used as the
basis of the culture media we are dealing with a solution of a very complex
and variable character, the exact nature of which it is extremely difficult
to determine, and that the ideal to be aimed at is to find a culture medium
with artificially prepared sea-water as its basis, such that the absence or
diminution in quantity of any one of its constituents would have a pro-
found effect upon the growth of diatoms in it. A reference was made
(loc. cit., p. 446) to some experiments with artificial sea-water, which,
whilst pointing to the probability of successful work being possible on
these lines, were in themselves too uncertain to be satisfactory.
Experiments in this direction have been continued at intervals during
the past three years, and although the problem has not been completely
solved the results obtained seem to be of sufficient interest and import-
ance to warrant publication in their present incomplete form, more
particularly because points remaining to be cleared up probably require
a knowledge of the chemistry of organic compounds to which I cannot
Jay claim.
Stated in general terms the most interesting result so far obtained is
that in the artificial sea-water tried, made by dissolving Kahlbaum’s
pure chemicals in doubly distilled water, little or no growth of diatom
(Thalassiosira gravida Cleve) takes place, but if to this artificial sea-water
as little as 1 per cent of natural sea-water is added vigorous and large
cultures are obtained, and with an addition of about 4 per cent of
* Allen, E. J.,-and Nelson, E. W. ‘‘On the Artificial Culture of Marine Plankton
Organisms,” Journ. Mar. Biol. Assoc., VIII, 1910. Also in Quart. Journ. Micr. Sci.,
Vol. LV, 1910. The two papers are identical.
t Q.J.H.8., Vol. LV, p. 893.
NEW SERIES.—VOL. X. NO. 3, OCTOBER, 1914. 2D
418 E. U. AGEN
natural sea-water from the Laboratory tanks better cultures result than
have so far been got in any medium which has natural instead of artificia!
sea-water as a basis.
THE DIATOM CULTURE USED.
A culture of the diatom Thalassiosira gravida Cleve, isolated some
years ago,* which has been kept since then by successive inoculations in -
fresh culture medium, has been used almost entirely for these experi-
ments. This species is especially useful owing to the fact that in healthy
cultures the cells hang together in long chains, whereas when the culture
is unhealthy or becoming exhausted the chains break up. This is a most
useful guide when watching the progress of an experiment.
The Purity of the Culture.—The culture contains no other diatom except
T. gravida and no other organisms except bacteria. It would of course be
preferable, if it were possible, to remove all the bacteria, so as to deal with
a perfectly pure culture of the diatom. Many attempts have been made
to attain this end, but so far without complete success, though it has been
possible to carry the process of purification so far that only one species
of bactertum capable of forming colonies on a peptone-agar plate} was at
all abundant. The method adopted for purifying the culture was that of
differential poisoning, a suitable poison being added to a number of culture
flasks in a series of gradually diminishing strengths, in the hope that one
strength might be found which would kill the bacteria without killing the
diatom.
A measure of success was obtained with Copper sulphate in this way.
In the most successful case a solution of the salt was added to 100 c.c. of
culture medium containing Thalassiosira gravida in such proportion that
* Allen and Nelson, Joc. cit., p. 460. [Q.J.40.8., p. 412.]. The species was then
thought to be a variety of Thalassiosira decipiens. Subsequent examination by Mr.
Nelson has convinced him that it is really 7h. gravida. The extreme delicacy of the
siliceous skeleton of these diatoms makes the determination of species founded chiefly on
valve structure very difficult. The species was formerly thought to be a variety of
Thalassiosira decipiens Grun. since the only markings that were observed were character-
istic of this species, although no markings at all could be resolved with the great majority
of valves. Examination of the present cultures by Mr. Nelson with more perfect apparatus.
has shown the typical 7. gravida Cleve valve structure to which species this form is now
referred. It is not unlikely that the older cultures were a mixture of 7h. decipiens au
gravida from which the decipiens have died out.
+ It should be remembered that possibly the presence of some bacteria in the cultures
is necessary for their success, though Miquel (Ze Diatomiste, I, 1890-3, pp. 153-6) states
definitely that he obtained cultures of fresh water diatoms which were entirely free from
bacteria, and Richter (Ber. deut. bot. Gesell, XX1, 1903 and later papers) also succeeded in
obtaining such bacteria-free cultures on solid culture media.
CULTURE OF PLANKTON DIATOM 7HALASSIOSIRA GRAVIDA CLEVE. 419
the 100 c.c. contained -001 grams of CuSO, 5H,O0. After an interval of
twelve minutes a fresh flask containing 100 c.c. of culture medium was
inoculated with 1 c.c. from the first one. In the second flask a very fine
erowth of diatoms appeared, which was much more healthy and
vigorous than. untreated cultures, and contained far fewer bacteria, as
shown by peptone-agar plates.
Still better results were got, however, by a method which was first
recommended to me by Mr. D. J. Matthews, who had made use of it for
destroying bacteria in aquarium water. This consists im passing an
electric current through the sea-water between carbon poles, until a con-
siderable formation of hypochlorous acid has taken place and the water
smells strongly of chlorine. The following description of an experiment
will show how the method was applied in the case of the diatom cultures.
Experiment 449.—25 litres of sea-water from the Laboratory tanks,
which had been treated with animal charcoal and filtered through a
Berkefeld filter, were put in a sterilized square glass jar, and an electric
current varying from 1-7 to 1-5 ampéres was passed through it for three
minutes, two carbon plates* (sterilized by heating) being used as poles,
the plates being constantly moved as the current was passing. The
electrolysed water then smelt strongly of chlorine. It was allowed to stand
for one hour, and then 50 ¢.c. of it was added to a flask (x), which con-
tained 50 c.c. of unelectrolysed Berkefeld water,} to which had been added
a quantity of Thalassiosira gravida from the culture which was to be
cleansed.
Sixteen flasks (a-q) had previously been made ready, each containing
about 75 c.c. of sterile culture medium (outside sea-water treated with
Miquel’s solutions and boiled). After the electrolysed water had been in
contact witn the Thalassiosira for thirty-one seconds about $ ¢c.c. from
flask x was added to flask a, and similar amounts were added to the
remaining flasks b, c, d, etc., at intervals of about ten seconds for the
first two minutes, and then at longer intervals until the last flask q was
inoculated after the Thalassiosira had been in contact with the electro-
lysed water for four minutes.
In this way a series of culture flasks was obtained inoculated with
Thalassiosira which had been in contact with electrolysed water for vary-
ing times. The flasks were placed in a suitable position before a north
window and the diatoms allowed to develop. At the end of a week the
first flasks in the series (a, b, c, etc.) showed good growth, the later ones
* The size of each plate was 120 x 44 x 6 mm.
+ See Allen and Nelson, Joc. cit., p. 482 [(Q.J.IL8., p. 375].
420 E, <3. -ALEEN:
(m-q) showing little or none. At the end of three weeks the result was
quite different, for whilst the early flasks showed only moderate growths
and were already beginning to go off, a sure sign of contamination, two
amongst the later ones (m and o) showed very fine growths of a rich
brown colour and forming very long chains. The culture in flask 0 was
one of the best and most vigorous that I have obtained during the whole
course of my experiments, and sub-cultures from it remained excellent
for many months.
The following table shows for the last few flasks of the series the times
that the Thalassiosira remained in the electrolysed water, and the kind of
growth that was obtained :—
Flask. Time during which
Thalassiosira was in Result culture.
electrolysed water.
l. 2min. 28 secs. Moderate culture, not persisting very long.
m. 2 min. 43 secs. Very good culture, with long chains, second
best of series.
n. 3 min. 0 secs. No growth of Thalassvosira.
o. 3 min. 22 secs. Very fine culture, best of series, dark brown
colour and very long chains. Remained
good for a long time and gave a long series
of good sub-cultures.
p. 3 min. 40 secs. No growth of Thalassiosira.
q. 4 min. 0 secs. No growth of Thalassvosira.
(Flasks a-k all gave moderate growths which did not persist, with the
exception of flask # (1 min. 44 secs.), which had no growth.)
Peptone-agar plates inoculated with 1 c.c. from flask o showed bacteria
of two kinds only, a few large yellow colonies, and many minute, slow-
growing colonies. They were of quite a different character from plates
made from ordinary cultures of Thalassiosira, which were always crowded
with yellow colonies, mixed with a large number of large milk-white
colonies which liquefied the agar, both kinds of colonies developing very
rapidly.
After some experience it becomes easy to distinguish a clean culture
of T. gravida from one which is much contaminated by bacteria, by the
character and progress of the growth. In a clean culture, at any rate
during the summer months when the light conditions are favourable, the
growth is much more rapid and vigorous, the tendency to form long
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE. 421
chains is very great, especially at first, the colour is a deep rich brown,
and healthy growth in a flask will go on for months. In a contaminated
culture, on the other hand, growth is slower and only quite short chains
are seen, the colour is a much lighter brown, and the culture does not
continue to grow ina healthy way, generally forming auxospores and often
dying off altogether in the course of two or three weeks.
All the main conclusions detailed in this paper have been confirmed
with clean and healthy cultures. Experiments with contaminated cul-
tures are not, however, without value, since they sometimes emphasize
the differences between culture media that it is desired to compare, a
contaminated culture often failing to grow at all in an unfavourable
medium, whereas a clean culture might give a growth, less in amount, it
is true, but not much different in character from the growth in the control
culture in a favourable medium.
THE ARTIFICIAL WATER.
The artificial sea-water used in the experiments was made by dissolving
Kahlbaum’s pure chemicals in ordinary distilled water made in a copper
still which had been redistilled in all-glass apparatus after being treated
with bichromate of potash and sulphuric acid, to destroy volatile organic
matter. This double distilled water contained at most 0-01 mg. of am-
monia per litre.*
The composition of the water was based on the analysis of sea-water
published by Dittmar in the “ Challenger ” Reports. The figures given
by Dittmar are :—
Per 100 parts halogen.
0 ae aA we eee ed 99-848
Li) Pb ae cee 3402
SO a rie ete cee 11-576
COR Ae eck t 2742
CHO ead oe 3-026
MaOQM Rae ee ante. 11-212
sO rere eae 2-405
Na ONES i223 74-462
Dividing these figures by the respective molecular or atomic weights,
and treating those for Cl and Br together as chlorine, we get after
* In connection with the preparation of the artificial sea-water I received constant help
and advice from my colleague, Mr. D. J. Matthews. Without his ready assistance in con-
nection with all chemical questions this investigation could hardly have been carried out.
+ ‘‘Challenger” Report, Chemistry, Vol. I, p. 203.
422 Eo J.. AWLEN:
reducing Na,O to 100, the following figures, which give the relative
number of molecules or atoms :—
Na OTP h.e Seine. 100
Ke OR Re ei 2-130
MaQis i Snore: 23-104
CaO 26 Cee I 4-499
COR Saar Re Nek 0-519
BO SAii ae the 12-048
Ole f O25. Cee 234-54
which gives the following molecular proportions for the bases and radicals
separately :—
NBs cr AG pcan ake 100-0
Reo Pie ert eas 2-13
Mos Rear ge 11-55
Ca: Ara ay aeoeee 2:25
CORSA eee 0-259
DOL sateen ee 6-024
Ole ike Wigs eres 117-27
If we use solutions of salts containing a gram molecular weight per
litre, since 1 ¢.c. of each solution contains the same number of molecules,
the relative number of c.cs., keeping the proportional amounts of the
bases, the CO, and the SO, as above, and making the remainder chlorine,
will be :-—
INB@Ie eke tance: 99-58
KC) escape at 2-13
Gals \+ .esnc ne 2-25
Me@ls sonixcas 53
MeSQ4swessn en. 6°02
Nas@O senacc cts 0°26
Since these figures give the number of molecules of Na somewhat too
high, it was thought better to use 0°26 ¢.c. of sodium bicarbonate
(NaHCOs;) instead of the normal carbonate, and this has been done
~ throughout.
In making up artificial sea-waters it has been found most convenient
to prepare first of all gram molecular solutions of each of the above salts
and then to mix these in the proportions indicated. These molecular
solutions are easily prepared and the strengths of the chlorides compared
and corrected by titrating them with silver nitrate.
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE. 423
The following details of the preparation of the molecular solutions
may be of assistance to future workers :—
Msol. NaCl.
Msol. KCl.
Msol. CaCl,.
Msol. MgSO.
Kahlbaum’s ‘Sodium chloride for Analysis.” 58-5
grams dissolved in double-distilled water, and brought
to 1000 c.c. at 15°C.
Kahlbaum’s ‘ Potassium chloride.” 74:5 grams dis-
solved in double - distilled water and brought to
1000 c.c. at 15°C.
Kahlbaum’s “Calcium chloride cryst. for Analysis.”
About 300 grams were dissolved in about 1 litre
of double distilled water. On titration with silver
nitrate solution 2 c.c. of the above CaCl, solution
required 30-3 c.c. of AgNO;. 2 c.c. of Msol. KCl
required 8-34 c.c. AgNOs, so that 2 c.c. of Msol. K,C ,
would require 16-68 c.c. AgNO. The CaCl, solution
is therefore too strong in the proportion “= = 1-8166.
In order to get the Msol. CaCl, 1000 c.c. of the strong
solution prepared must be diluted to 1816-6 ¢.c. This
was done and the final solution again titrated against
the Msol. KCl.
Kahlbaum’s “ Magnesium Chloride for Analysis.” As in
the case of CaCl, a strong solution was first prepared,
titrated with AgNO, and diluted with double-distilled
water to the required extent, Msol. KCi being used
as standard.
Kahlbaum’s ‘‘ Magnesium Sulphate for Analysis.”
Crystallized magnesium sulphate has the formula
MeSO, 7H,0, the molecular weight of which is
246-4. To make the molecular solution 2464 grams
of the salt were dissolved in double-distilled water
and brought to 1000 c.c. at 15°C.
Msol. NaHCO,. Kahlbaum’s “Sodium Bicarbonate for Analysis.” 84
grams dissolved in double-distilled water and brought
to 1000 c.e.
In order to prevent the growth of moulds in the stock solutions these
were all brought to the boil and kept in sterilized glass-stoppered bottles,
the stoppers being tied down with a cap of parchment paper which was
taken directly out of boiling water. When any of the solution was used,
424 EH: J. ALLEN:
the parchment cap was removed and placed in boiling water, the bottle
was carefully opened and the amount of solution required poured out,
the stopper being quickly replaced and tied down. These precautions are
important, as the growth of mould in the solutions may have an important
influence on the diatom cultures.
It has generally been found most convenient to make up the sodium
chloride solution, of which large quantities are required, as it is wanted,
and not to store it.
In the last table above the relative amounts (c.cs. of M solutions) of
the different salts required to prepare the artificial sea-water are given.
There remains to consider the actual salinity of the water which we are
to employ, which is generally expressed as the weight in grams of the total
salts contained in 1000 grams of the water. The salinity of natural sea-
water in the western portion of the English Channel generally varies from
about 35-5 to 35-0 per thousand, the water being generally lower in salinity
near the coast. In laboratory experiments the water in the flasks becomes
progressively more concentrated owing to evaporation, and a low salinity
has therefore been adopted for the artificial sea-water used, namely, 35-0
per thousand.
The following table gives the composition of an artificial sea-water
having a salinity of 35 per thousand, and with the salts in the relative
proportions obtained above from Dittmar’s analysis. The composition
is stated (1) as the number of cubic centimetres of gram molecular solution
contained in 1000 c.c. of the artificial water, and (2) as the number of
erams of each salt contained in 1000 c.c.
c.cs. of M. solution Grams
contained in per
1 litre. litre.
NaCl 480-80 28.15
KCl 10-28 0-77
CaCl, 10-86 1-20
MeCl, 26-70 2-55
MesO, . 29-06 3-50
NaHCO, 1.25% 0-11
To make up a litre of artificial sea-water the simplest procedure is
therefore to weigh out 28-13 grams of sodium chloride, dissolve it in about
half a litre of double-distilled water placed in a 1 litre flask, add the re-
* 2-6 c.c. was the amount generally used, as the increased alkalinity is favourable to
diatom growth. See below.
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE. 425
quisite number of cubic centimetres of M solutions of the other salts
(KCI 10-28, CaCl, 10-86, etc.) and then make the whole up to exactly
1 litre by adding double-distilled water.
Water prepared according to the figures given in this table was titrated
for me by Mr. Matthews against the standard water supplied by the
International Council, and was found to have a salinity of 35 per
thousand.
Alkalinity.—The alkalinity has also been compared with that of sea-
water from outside the Plymouth Breakwater by Sorensen’s method, and
was found to be very close to it, the artificial water being slightly less
alkaline. It was found experimentally that better growths of diatoms
were obtained when the alkalinity was increased somewhat,* the best
result being obtained when an extra 1-33 ¢.c. of Msol. NaHCO, per litre
was added, making a total of 2-6 c.c. of the molecular solution of this salt.
DIATOM CULTURES IN ARTIFICIAL SEA-WATER.
As was to be expected, it 1s not possible to obtain cultures of diatoms
in the artificial sea-water prepared as described in the last section as it
stands. The water must be first treated with nutritive solutions, and for
this purpose the modifications of Miquel’s solutions described in our
former papery have been used. Two solutions are employed as follows :—
Solution A.
Potassium nitrate 20-2 erm. ,
Distilled water to 100 oe eee
Solution B.
Sodium phosphate (Na,HPO,12H,O) 4 grm.
Calcium chloride (CaC!,6H,0) a,
Ferric chloride (melted) 2 e.c.
Hydrochloric acid (pure, concentrated) 2 c.c.
Distilled water 80 ¢.c.
To each 1000 c.c. of artificial water add 2 c.c. solution A and 1 c.c. solution
B. Sterilize by bringing to the boil. When cool decantt off the clear
* Cf, Allen and Nelson, Joc. cit., p. 452 [Q.J.M.S., p. 401]. The figure here given
was derived from later experiments.
+ Allen and Nelson, Joc. cit., p. 428 [Q.J.ILS8., p. 370]. For details as to the pre-
paration of Solution B that paper or Miquel’s original account should be studied.
+ Filter papers should not be used to filter off the precipitate. They appear to contain
some substance which inhibits the growth of the cultures. The cultures were made in
wide-mouthed spherical glass flasks covered with glass capsules. Cotton wool plugs were
not used, as these were found to be injurious to the growth of the diatoms.
496 i; 1d ADEE:
liquid from the precipitate which is formed on the addition of solution B.
The clear liquid is referred to in what follows under the name “ artificial
miqueled water.”
It was found, however, that even after the addition of these two
solutions very slight growth, if any, took place on inoculating with a small
quantity (say one drop) of healthy Thalassiosira gravida culture. This was
the case even after the addition of potassium bromide and iodide, or of
Miquel’s own solution A, which contains these two salts. If, on the other
hand, the artificial miqueled water was inoculated with a considerable
quantity of a culture of Thalassiosira in which natural sea-water had
formed the basis of the culture medium, so that a considerable quantity
of this natural water was transferred to the artificial medium, then the
latter would develop a fine healthy growth. Experiences of this kind led
me to suspect that the irregularities which ‘had previously been met with
in trying to make cultures in artificial media* might be due to varying
amounts of natural sea-water introduced when inoculating. Definite
experiments were therefore undertaken in order to ascertain whether the
addition of natural sea-water to the artificial miqueled water would make
it effective as a culture medium, and if so what proportion of natural
sea-water was essential. In all cases the culture medium was boiled after
the addition of the natural sea-water and then allowed to cool before inocula-
lion.
As a result of these experiments it was shown that an addition of even
1 per cent of natural sea-water to the artificial miqueled water was suffi-
cient to give very heavy cultures after moculation with only one drop of
Thalassiosira culture, and that with an addition of 4 per cent of natural
sea-water better cultures were obtained than in any other culture medium
known to me. This result has now been obtained so many times that it
is in my opinion quite definitely established. If the proportion of natural
sea-water added is reduced below 1 per cent smaller growths are
obtained, and it is somewhat difficult to decide whether there is a definite
minimum below which no growth takes place. An addition of 0-3 per
cent of natural sea-water in one satisfactory experiment produced quite
a heavy growth, whereas without this addition only a small growth was
obtained. It has often been observed that whilst flasks containing 75 c.c.
of artificial miqueled water show distinct signs of diatom growth when
inoculated with one or two drops of a culture of Thalassiosira in natural
sea-water, such flasks inoculated with one or two drops of a culture which
has artificial sea-water as the basis of the culture medium show practi-
* Allen and Nelson, Joc. cit., p. 447 [@.J.IL.S8., p. 394].
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE, 427
cally no signs of growth at all, and remain quite clear. Since the above
conclusions were reached it has been my practice in critical experiments
always to inoculate from a culture in the artificial medium, so as to reduce
the amount of natural water carried over on inoculation to a minimum.
From what has been said it seems clear that there is in natural sea-
water some substance (or substances) not contained in the artificial water
treated with Miquel’s solutions, minute traces of which are essential to
the growth of Thalassiosira. That the quantity present in the culture
flasks after the addition of even 4 per cent of natural sea-water must
be extremely minute is obvious from the fact that all subst inces which are
present in natural sea-water in quantities beyond a mere trace are con-
tained in the artificial culture medium. It becomes a matter of great
interest and perhaps also of great importance to endeavour to find out
what this substance may be, of which such exceedingly minute traces
make all the difference between practically no growth at all and a vigorous
and continued development of the diatoms, for the growths once started
may go on increasing rapidly and healthily for several months.
The addition of many substances, both organic and inorganic, to the
artificial miqueled water has been tried, generally in several concentra-
tions, but up to the present no definite chemical compound has been
found which can take the place of the 1 per cent of natural sea-water.
Of inorganic substances the following have been tried in different
concentrations without result: Potassium bromide, potassium iodide
(alone and with bromide), gold chloride, potassium nitrite, aluminium
chloride, strontium chloride, lithium chloride and lithium carbonate.
It may be suggested that silica is the missing substance, but this seems
precluded from the fact that all the experiments have been carried out
in glass vessels, and the amount of silica which would go into solution
from the glass would certainly be greater than that contained in the
added 1 per cent of natural sea-water. Richter * has shown that dia-
toms grown in glass vessels obtain the silica they require from the glass.
In the course of the experiments it was found that the addition to the
artificial miqueled water of a small percentage of sea-water from the
tanks of the Plymouth Laboratory gave distinctly better cultures than
the addition of the same percentage of natural sea-water brought in
from outside. This comparison has been repeated a great many times,
and the difference has been so marked and constant that I am compelled
to regard it as firmly established. Different samples of sea-water brought
* Richter, O., Verh. d. Gesell. deut. Naturf. u. Arte., Breslau, II, 1904, and S.B.K,
Akad. Wiss. Wien., CXV, 1906.
428 E, 31 SkLLENS
in from outside also appear to give somewhat different effects, and,
although the experiments have not given sufficiently uniform results to
justify a definite statement, I am left with the impression that on the
whole samples of water taken from Plymouth Sound, when added to the
artificial medium, give better growths than are obtained with samples
from the English Channel in the neighbourhood of the Eddystone.
Now the tanks at the Plymouth Laboratory are worked on a closed
system of circulation, the same water being circulated over and over
again, so that the principal difference between the water taken from
them and that obtained from outside consists in the greater abundance
in the tank water of organic compounds, which result from the meta-
bolism of living organisms. Is it the presence of some organic substance
that is necessary for the growth of the diatoms ? A very large number
of experiments have been made with a view to obtaining some light upon
this question, and some of these will now be referred to.
Ulva infusion. A small piece of green seaweed (about 1 square cm. of
Ulva latissima) was boiled for about five minutes in a flask containing 75 c.c.
of artificial miqueled sea-water, and was then removed with a sterile
platinum needle. In this way a weak organic infusion was obtained.
When cold the flask was inoculated with one or two drops of Thalas-
siosira from a culture in artificial water. In this organic infusion a good
growth was obtained, nearly equal to that in the control in artificial
miquel plus 4 per cent of tank water. This experiment was repeated a
number of times with a similar result.
Though it is most probable that the result is due to some organic com-
pound the experiment is, of course, not conclusive, as an inorganic salt
may have been dissolved from the ulva. In any circumstances we
obtain no hint as to the nature of the organic substance, and the result
remains indefinite.
It may be pointed out that Miquel * in his account of his original .
experiments on diatom cultures, insists upon the value of the addition
of some organic infusion or maceration to his culture solutions.
Ulva Extract. A piece of Ulva latissima was washed in several changes
of artificial sea-water and then an extract was made in absolute alcohol at
a temperature of 58° C. The alcohol was evaporated to dryness on a
water-bath. 75 c.c. of artificial miqueled sea-water was then boiled in
small portions at a time in the vessel containing the extract, so that all
soluble parts of the extract were dissolved. The water was then re-
turned to a culture flask, which, when cold, was inoculated with Thalas-
* Le Diatomiste, I, 1890-3, p. 95.
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE. 429
siosira, as described in the experiment with ulva infusion. No growth
was obtained in the flask.
Ulva Ash. A piece of ulva measuring about 5 cm. by 3 cm. was
washed in several changes of double-distilled water. It was then put in a
porcelain crucible, dried and heated over a bunsen burner till it was
reduced to a white ash. The ash was added to a flask containing 75 c.c.
of artificial miqueled sea-water, which was boiled, allowed to cool and
- inoculated with Thalassiosira, as in the two previous experiments. The
result of the experiment was again negative.
Experiments with Hemimysis. In order to test whether the products
of animal metabolism could immediately supply the substance sought
for, the following experiment was carried out with Hemimysis lamorne
Couch, a small crustacean which lives in numbers in the Laboratory
tanks. In the first experiment (Exp. 404) four Hemimysis were passed
through two changes of Berkefeld filtered water, the animals being placed
on a piece of filter paper to remove surplus fluid before being placed in
each change of water. They were then passed in a similar way through
two changes of artificial miqueled sea-water (75 c.c. was used altogether,
being divided into two portions), and finally placed in a fresh quantity of
the artificial miqueled sea-water (75 c.c.). They remained healthy and
active and deposited a considerable amount of feces on the bottom of
the vessel. After they had been in the water four hours the Hemimysis
were taken out and the water placed in a culture flask and brought to
the boil. A control experiment with 75 c.c. artificial miqueled sea-water
to which 3 c.c. of tank water had been added was set up and brought to
the boil in the same way. On the following day both flasks were in-
oculated with two drops of a Thalassiosira culture. During the first
week there was a very small growth of diatoms in the flask with the water
in which the Hemimysis had been, which died out during the next few
days. This growth was similar to that which usually occurs in artificial
miqueled water to which nothing has been added. The control experiment
to which 3 c.c. tank water had been added gave a very fine growth from
the first, which persisted for at least five months. The result of this
experiment was therefore negative. In another experiment, carried out
in other respects in practically the same way, the Hemimysis were
allowed to remain living in the water for twenty-four hours before
they were removed. The result was again negative.
In a third experiment five Hemimysis lived for nineteen hours in 75 c.c.
artificial miqueled sea-water to which 3 c.c. of tank water had been added.
The animals were removed, the water boiled, and when cold inoculated as
430 Bee AL NE
before with Thalassiosira. A good growth resulted, shoving thet the
animals do not excrete substances which completely inhibit the growth
- of the diatoms.
Evaporated Tank Water. A number of experiments were made in
which a quantity of sea-water from the Laboratory tanks was evaporated
to dryness on a water bath, the residue heated to different degrees,
treated with strong, pure hydrochloric acid and evaporated two or three
times to get rid of the acid, and then redissolved to the original volume
in double-distilled water. After being neutralized by the addition of
NaHCO,,-4 per cent of the resulting solution was added to artificial
miqueled sea-water, the resulting culture medium being boiled, cooled
and inoculated with Thalassiosira in the usual way.
The results of these experiments are set out in summary form in the
annexed Table A. In each case proper control experiments were set up
at the same time, generally one with artificial miqueled sea-water to
which nothing was added, and one with the same water to which 4
per cent of tank water was added, and the controls were boiled at the
same time as the other flasks of the experiment.
As is seen from the table, five series of experiments were made. In the
first (Series A) the salts obtained by evaporating the ‘ank water were
heated in a porcelain dish over a bunsen burner, the heating being carried
out carefully so that the flame did not actually touch the dish, which
never became anywhere near red hot. In Series B the evaporation and
heating were done in a platinum basin, which was raised to a dull red
heat over a bunsen. In Series C the salts were again evaporated and
heated in a porcelain basin and made as hot as they could be with a
bunsen burner, the flame of which played directly on the outside of the
dish, and was moved about so as to heat different portions in turn. In
Series D the salts were heated in a hot-air oven, being kept at a tempera- -
ture of 164° to 170° C. for an hour. In Series E the heating was again
carried out in a hot-air oven, a temperature of from 200° to 237° C. being
maintained for two hours.
In Series A, D and E, where the heating of the residue was not excessive,
quite good cultures resulted. Although they did not quite come up to the
controls in which 4 per cent of tank water was added, they were in
every case altogether of a different order from what took place in the
controls in artificial miqueled sea-water to which nothing had been
added.
In the other two series, B and C, where the degree of heating was much
ereater, in most cases the culture was an entire failure, and in those
431
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE.
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432 RK. J. ALLEN:
instances in which some growth was obtained it was distinctly below
that of cultures of the former series made at the same time.
A study of Table A can, I think, leave no doubt that the general
statement is justified that whatever the substance may be which occurs
in tank water and the addition of which to artificial miqueled sea-water
enables the latter to support a vigorous diatom growth, that substance
may be dried and heated to a moderate degree without greatly impairing
its efficacy, whilst if it is heated to too high a temperature its efficacy
tends to be destroyed.
The experiments are consistent with the theory that the substance
1S an organic compound, but one of a very stable kind, which is only
decomposed with difficulty.
Addition of organic substances to artificial water. Many experiments
have been made by adding organic substances in a number of different
concentrations to artificial miqueled sea-water, but by none of these has
any marked or constant effect been produced upon the growth of Thalas-
siosira. It will be understood, of course, that such negative results are in
no way conclusive, as in a case of this kind the attainment of an exactly
correct degree of concentration may be essential, and when one is working
quite without clue it is hardly possible to carry out a sufficiently extensive
series of experiments with every substance, especially when two or three
weeks must elapse before the result of any experiment becomes definite.
The following substances have been tried : asparagin, calcium succinate,
calcium malate, sodium salicylate, theobronine, leucine, tyrosine * (the
three latter alone and together with atropine),f peptone, urea and uric
acid. In all cases the result was negative.
Putrified Peptone. An isolated result which I have entirely failed to
repeat in spite of many attempts may be worth putting on record as a
hint for future work, but no other importance should be attached to it.
Starting from the idea that the substance sought for might be one of the
ultimate products of the breaking down of organic matter under the
influence of bacteria, since it appears to be more abundant in the tank
water of the Laboratory than in sea-water from outside, the following
* In consequence of the work of Thornton and Geoffrey Smith on Euglena (Proceed.
Roy. Soc., B., Vol. LXXXVIII, p. 151, 1914) special attention was given to tyrosine, and a
arge number of different concentrations were tried. Entirely negative results were, how-
ever, obtained.
+ The use of these three substances alone and with atropine was suggested by the work
of H. C. Ross on ‘‘ Auxetics.’”” See H. C. Ross, Znduced Cell-Reproduction and Cancer,
London, J. Murray, 1910; Further Researches into Induced Cell-Reproduction and Cancer,
I and II, London, J. Murray, 1911 and 1912.
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE. 433
experiment was carried out. 100 ¢.c. of a 1 per cent solution of peptone
in artificial sea-water was sterilized by boiling on successive days. When
cold it was inoculated by.adding two drops of tank water. Under the
influence of the bacteria of the tank water putrefaction set in and was
allowed to continue for nineteen days. The solution was then again boiled.
To 75 c.c. of artificial miqueled sea-water three drops of the putrified pep-
tone solution were added, and the flask boiled, and when cold inoculated
with two drops from a culture of T'halassiosira in artificial miqueled water
plus 4 per cent of outside sea-water. At first the water in the culture flask
became milky from the growth of bacteria, but this milkiness gradually
disappeared and the diatoms commenced to grow, giving finally an
excellent culture which was quite up to the control. I do not think
there was any flaw in the actual carrying out of the experiment, but,
as already mentioned, a number of attempts to repeat it all gave nega-
tive results.
A final point may be mentioned, which also seems to suggest some
organic substance as the missing factor which the artificial miqueled sea-
water must contain before it will sustain a vigorous growth of the diatoms.
It has been noticed that artificial miqueled sea-water which has been
kept for some weeks gives (without any addition of natural sea-
water) more growth than does similar water used within a few days of
being prepared. Plate-culture tests have shown that such water after a
few days develops bacteria, and it is possible that the products of the
metabolism of these bacteria are able to help the growth of the diatom.
The Omission of Miquel’s Solutions. Vi 4 per cent of tank water
(i.e. water from the Laboratory tanks, which are worked on a close
system of circulation *) be added to artificial sea-water, made according
to the formula already given, but to which neither of the Miquel solutions
is added, a good growth will result after sterilization and inoculation
with Thalassiosira. This growth may for the first week or two be quite
as good as a similar culture to which the Miquel solutions have been
added, but it will not continue healthy for as long as the latter, so that
the total growth will be less. It is interesting to note that the mere
dilution of the tank water with pure artificial sea-water produces an
increase of growth, for the amount of growth obtained in say 100 c.c.
of sterilized tank water is less than that obtained in a mixture of
96 c.c. of artificial sea-water with 4 c.c. of sterilized tank water. This
is partly explained by a difference in alkalinity, but it also suggests
that the tank water contains not only an abundance ‘of the food sub-
* Cf. Allen and Nelson, loc. cit., p. 430, et seg. [Q.J.ILS., p. 373].
NEW SERIES—VOL. xX. NO, 3. OCTOBER, 1914. 2E
434 KE, (Joe aNe
stances which the diatoms require, but also substances which in higher
concentrations are detrimental to growth, whereas in low concentrations
their inhibitory action is reduced or disappears.
CHANGES IN THE COMPOSITION OF THE ARTIFICIAL
SEA-WATER.
A series of experiments was made to ascertain to what extent the
composition of the artificial sea-water could be changed without affecting
the growth of Thalassiosira, and it was found that, provided 4 per
cent of natural sea-water were added, the various constituents of the
artificial water might be varied to a surprising extent without in any
way retarding the growth. Only those results are included here which
were quite marked and definite. Other variations in composition were
tried, but an account of these is reserved until the experiments have
been repeated and extended. .
Varying the Amount of Magnesium Sulphate. A series of flasks was
set up, the basis of the culture medium in each being artificial sea-water
prepared according to the table on p. 424, the quantity of magnesium
sulphate being varied. The full amount of alkali favourable to diatom
growth was added (i.e. 2-6 c.c. of M.NaHCO, per litre), together with
the usual quantities of 20 per cent KNO; and Miquel’s solution B
(Na,HPO,; CaCl,; FeCl,;; HCl) and 4 per cent of natural sea-
water. The series contained (a) no magnesium sulphate, (b) ¢ the normal
amount, (c) $ the normal, (d) 2 normal, (e) the normal amount, Le.
29-06 c.c. of M.sol. per litre, (f) 14 times the normal and (g) 1} times the
normal. All the flasks were inoculated in the same way with Thalas-
siosira gravida. During the first month all the flasks gave excellent
growths, and it was not possible to distinguish between them. At the
end of three months (a) and (b) had gone off more than the others, and >
(f) and (g) were not quite up to (c), (d) and (e). A repetition of (a) to (e)
again gave the same result, the cultures being particularly large
and healthy. In speaking of this result, it must be remembered that
although the only sulphur present in (a) was that introduced in the
4 per cent of natural sea-water a considerable amount of magnesium was
present as magnesium chloride.
Varying the Amount of Calcium Chloride. Another series of experiments.
was made in every respect similar to the last, excepting that the calcium
chloride in the artificial water was varied instead of the magnesium
sulphate, which remained normal: (a) contained no calcium chloride,.
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE. . 435
(6) | normal amount, (c) } normal amount, (d) 3 normal amount, (e) the
normal amount, 1.e. 10-86 c.c. M.sol. CaCl, per litre, (f) 14 times the
normal amount, (g) 14 times normal.
(2) During the first week showed little sign of growth and was far
behind the others. At the end of a month, however, there was
quite a good growth, still very healthy, but the quantity was far
below that in (e), (d), (e), (f) and (q).
(6) Small growth during the first week and remained always better
than (a), but never equal to (c), (d), ete.
(c) Fair growth during first week and went on well, though the quantity
was never up to (d), (e), ete.
(d) The growth was nearly equal to the normal (e) throughout, and at
the end of a month it was not possible to distinguish between
the two. .
(e) A fine healthy growth with long chains.
(f) About the same as (d) throughout.
(g) About the same as (d) and (f) throughout.
A repetition of (a) to (e) gave just the same result. In connection with
this series it must be noted that Miquel’s B solution contains CaCl,, so
that the amount of Ca present in (a) will be that contained in the
4 per cent of natural sea-water, plus that contained in the Miquel B.
Varying the Amount of Potassium Chloride. An exactly similar series
was set up in which the potassium chloride was varied from 0 to 14 times
the normal. All these gave very fine growths, of which the last two
(14 and 14 times normal) were the best during the first week. Subse-
quently it was not possible to distinguish between the amounts in the
different flasks. This result was also confirmed by a second experiment.
It should be remembered that potassium was added as nitrate in this
as in the other experiments (2 c.c. of a 2 M.sol. KNO, per litre).
Variations in Salinity. It was shown in our previous paper * that in
the case of Skeletonema costatum, Biddulphia mobiliensis and Coscinodiscus
excentricus, plankton diatoms of very similar habit and distribution to the
species Thalassiosira gravida chiefly used in the present experiments, the
salinity of the culture medium could be varied within wide limits without
greatly affecting the growth of the diatoms. Thus between 35 and 40
per cent of the water could be evaporated from a culture medium having
natural sea-water as its basis without seriously affecting the growth of
the diatoms, whilst dilution of the culture medium up to 100 per cent
* Allen and Nelson, Joc. cit., p. 453 (Q.4.I.8., p. 402].
436 E. J. ALLEN.
also made no appreciable difference. Even when the dilution was ex-
tended to 200 per cent a fair quantity of growth took place.
The following experiment was made in order to test the same point on
Thalassrosira gravida.
Experiment 476. Artificial sea-water was made up with the normal
relative proportions of salts, but of double the normal strength. A series
of dilutions was then prepared, doubly distilled water being added in the
proportions stated :
Artificial sea-water, Doubly distilled
double strenth. water added.
C.C. c.C.
ne 100 + 0)
B 100. 32 “35
C 100 + 50
D 100 + £75
E 100 + 100 Normal
F 100 + 125
G 100 + 150
4 H 100 + 175
J 100 + 200
The right quantities of Miquel’s solutions were added to each, and
4 per cent of sea-water from the Laboratory tanks. Flasks were then
inoculated with three drops each of Thalassiosira gravida culture. No
erowth took place in A and B. Excellent, healthy growths with good
chain formation took place im all the others. E and F were best, and one as
good as the other. G and D were excellent growths, but the quantity at
any time was less thanin Eand F. InC, H and J, although the growths
were quite good the quantity was considerably less than in E and F, that
in C also being less than in H and J.
It will thus be seen that very considerable changes in the salinity of the
culture medium can be made without much effect beg produced on the
growth of Thalassiosira. Dilution of the medium is less detrimental than
concentration.
The experiments described in this section show how wide the
variation in the chemical composition of the culture medium may be
without any very marked effect being produced on the growth of the
diatoms. The difficulty in growing the diatoms in artificial sea-water is
clearly not due, as at one time I thought might be the case, to the fact that
a very delicate balance between the amounts of the different salts is
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE. 437
necessary and that this balance had not been attained sufficiently exactly
in preparing the solutions. It is quite clear that the artificial sea-water
lacks some substance which occurs in natural sea-water, and that a very
small trace of this substance is sufficient to make the difference between a
considerable and continued growth of the diatoms and practically no
erowth'at all.
GENERAL CONSIDERATIONS.
Several instances have recently been described which seem to show that
in food material used to support animal life the presence of minute traces
of particular organic substances is essential, if the food material is to
maintain the animal body in a healthy state.
The work of Leonard Hill, M. Flack, G. Hopkins and Casimir Funk *
has shown that in the outer layers of wheat and rice there is an active
principle which is of essential importance to their value as food material.
Young rats and mice would not live when fed exclusively upon white
flour in the preparation of which the outer layers of the wheat had been
removed, whilst those fed on whole meal flour did much better. Pigeons
could be successfully fed on bread made of white flour to which an extract
of bran and sharps had been added, but when fed on pure white bread all
died. Polished rice from which the husk has been removed in the process
of polishing, when used as an exclusive diet, produces the disease known
as beri-beri. Cooper and Casimir Funk + were able to isolate from rice
polishings a substance to which they gave the name vitamine, which
effected a rapid cure when given to pigeons suffering from beri-beri.
The same substance was obtained from yeast, from milk and from bran.
Hopkins { has shown that young rats do not grow on an artificial
diet composed of pure protein, starch, cane sugar, lard and morganic
salts, but if quite a small quantity of natural milk is added to the
diet they thrive.
Thornton and Geofirey Smith § have shown that strong growths of
Euglena viridis in culture media prepared according to Miquel’s formula
are produced when in place of the organic matter used by Miquel slight
traces of amido acids are added to the solutions of inorganic salts. Tyrosin
in the proportion of 1 in 24,000 gave an optimal growth, The authors
* A summary of this work, as described at the meeting of the British Association in
Dundee (1912), will be found in Science Progress, January, 1913, pp. 423-5.
+ The Lancet, Nov. 4th, 1911, p. 1266.
% Journal of Physiology, Vol. XLIV, 1912, p. 425.
§ Proceed. Roy. Soc., B., Vol. LXXXVIII, p. 151, 1914.
438 E. J. ALLEN
suggest that the amido acid acts as an auxiliary or stimulant rather than
as the main source of nutrition. This view is similar to that taken by
H. C. Ross in his work on Induced Cell-Reproduction and Cancer, to
which reference has already been made (see p. 432).
It would seem that the plankton diatoms, the culture of which has been
considered in the present paper, show a phenomenon of a similar character
to those just mentioned. The minute trace of substance added to the
culture medium in the small percentage of natural sea-water would seem
to act as a catalytic agent, initiating the processes of metabolism but not
being itself used up.
The experiments may also help to throw light upon what takes place
in the sea. It is well known that the waters of the open ocean far from
land support a much smaller proportion of plant and animal life than is to
be found in coastal waters. On the other hand, in regions where a current
of coastal water meets and becomes mixed with a current of ocean water
conditions are produced which are specially favourable to a luxuriant
srowth of animal and vegetable life. This is shown in the first place in
the very rich character of the plankton, and as a consequence of the
abundant plankton we find a rich fauna of bottom living organisms and
of fishes of different kinds. This is in agreement with the observation
recorded in the present paper that a small quantity of natural sea-water of
an inshore type (tank-water) mixed with a large proportion of pure
artificial sea-water gives a good culture medium for the plankton
diatoms. There is reason to hope therefore that culture experiments
may in time throw additional light upon the general questions relating
to the production of animal life in the sea, questions which are of
immediate importance to a study of the productivity of the fisheries.
SUMMARY.
1. Attempts to obtain good cultures of Thalassiosira gravida in a purely
artificial medium, made by dissolving in doubly distilled water
Kahlbaum’s pure chemicals in the proportions in which the salts
occur in sea-water, adding nitrates, phosphates and iron according
to Miquel’s method and sterilizing the medium, have not succeeded.
2. If, however, a small percentage of natural sea-water (less than 1 per
cent will produce a result) be added to the artificial medium and
the whole sterilized excellent cultures are obtained, which are often
better than any which have been got when natural sea-water forms
the foundation of the culture medium.
CULTURE OF PLANKTON DIATOM THALASSIOSIRA GRAVIDA CLEVE, 439
3. The result appears to be due to some specific substance present in
minute quantity in the natural sea-water which is essential to the
vigorous growth of the diatoms. The nature of this substance it
has not been possible to determine, but. some evidence seems to
suggest that it is a somewhat stable organic compound.
4. Provided the 1 per cent of natural sea-water is added, the various
constituents of the artificial sea-water forming the basis of the
culture medium can be varied in amount within wide limits. The
salinity of the medium can also be considerably altered without
serious detriment to the cultures.
5. The experiments recorded are of interest as furnishing another instance
of the importance in food substances of minute traces of particular
chemical compounds. They may also eventually throw light upon
the nature of the conditions in the sea which are specially favourable
to the production of plant life and therefore also of the animal life
which that plant life sustains.
ADDENDUM.
Since the above was printed a paper has been published by Prof. W. B.
Bottomley on “‘ Some Accessory Factors in Plant Growth and Nutrition ”
(Proceed. Roy. Soc., B., Vol. LX X XVIII, p.'237, Sept., 1914), in which it is
shown that a minute trace of an organic substance, which is formed by the
action of aérobic soil bacteria upon peat, acts as a powerful stimulant to
the growth of plants and of nitrogen-fixing bacteria. Following the
method of Cooper and Funk for obtaining “ vitamines”’ from rice polish-
ings, namely, by precipitating by phosphotungstic acid from an aqueous
solution of the dry residue from an alcoholic extract, Bottomley has
succeeded in obtaining from the bacterized peat a substance which is
quite as powerful a stimulant to plant growth as the original alcoholic
extract of the bacterized peat. This substance, as in the case of Funk’s
vitamines, can be further purified by precipitation with silver nitrate and
baryta, the resulting substance being an effective growth stimulant.
[ 440 ]
A Study of the Restitution Masses formed by the
Dissociated Cells of the Hydroids Antennularia
ramosa and A. antennina.
By
W. De Morgan and the late G. Harold Drew,
Beit Memorial Research Fellow,
From the Laboratory of the Marine Biological Association at Plymouth.
Figures 1-9 in the Text.
TABLE OF CONTENTS.
PAGE
Introduction . c . . : : é : > 3 5 : . 440
Methods and Technique . ; é . 443
The normal tissues which, after seees don: give rise to ae rosreuniGe masses. 445
The process of formation of restitution masses. : 5 : : . 448
The morphology and duration of life of the M abinone masses 5 ; : . 451
The histology of the restitution masses. 3 : ; ; ; 5 . 453
Synopsis of experiments . : . : . E ; 5 : : . 458
Summary and conclusion ; 6 : : é : : é : . 462
INTRODUCTION.
THE work described in this paper is, in the main, a repetition of that
of H. V. Wilson, ‘‘ On the Behaviour of the Dissociated Cells in Hydroids,
Alcyonaria, and Asterias,” published in October, 1911, in the Journal
of Experimental Zoology. The results he obtaimed are so far-reaching
in their bearmg on the present theories of the organization of living
matter that his work appeared well worth repeating on species closely
allied to those on which he experimented. Our results largely bear out his
contentions, though we were not successful in carrying the regenerative
process as far as the production of new hydranths, and the histological
structure of the restitution masses we obtained differed in many ways
from that described in Wilson’s paper. These differences are probably
due to the fact that we experimented with other species of Hydroids to
those used by Wilson : in other respects we have followed his technique
and repeated his experiments, and up to a certain point have obtained
the same results, and thus it may be considered that we have verified his
very remarkable work.
A STUDY OF RESTITUTION MASSES. 441
The especial interest of our investigations lies in the rather anomalous
fact that we have not been successful in obtaining regeneration of the
complete organism from the dissociated cells. In our experiments the
restitution masses, by some rearrangement or metaplastic process taking
place among their conglomerated cells, formed tissue aggregates histologi-
cally reduplicating the structure of the parent organism, but in a quite
irregular and apparently meaningless manner. The masses consisted
of irregular convoluted tubules lined with endoderm cells, imbedded in
closely packed but irregularly’ arranged ectoderm cells, among which
many isolated endoderm cells were distinguishable, and the whole tissue
aggregate was surrounded by a transparent perisare which it had secreted.
Slight contractions and alteration in shape in the cell masses often took
place even after several weeks, and many of them remained alive and
showed no signs of degeneration for at least fifty days, which was very
much longer than the Hydroids themselves could be kept alive under
similar conditions.
Before proceeding further it will be as well to briefly summarize the
results obtained by H. V. Wilson. The Hydroids on which he experi-
mented were Hudendriwm carneum Clarke, and Pennaria tiarella Mc-
Crady. Proceeding as described in his paper, he squeezed pieces of the
Hydroids through bolting silk of 50 and 75 meshes to the inch and then
allowed the dissociated cells to form aggregate masses. The following
is an abstract of some of his experiments.
EKudendrium carneum.
Experiment, July 9. A colony was squeezed, and fusion was observed
under the microscope. In a few hours irregular, lobed, flattened
masses about 5 mm. wide and 1 mm. thick were formed. By the
next day, a perisarc surrounding the whole mass had been secreted.
In 4 days outgrowths had formed in which ectoderm and. endo-
derm could be distinguished. Some of the masses died, but others
remained alive. These were isolated, and in 24 hours, one pro-
jecting outgrowth ended in a hydranth, and a day later two com-
pletely formed hydranths were developed from another mass.
These hydranths have the characteristic size, shape, and colour of
the normal adult polyp.
Experiment, July 14. The tissue died before mass formation.
Experiment, July 15. Flattened plasmodial masses and lumps were
formed, but soon died.
443 W. DE MORGAN AND THE LATE G. HAROLD DREW.
Experiment, July 18. Tissue died.
Experiment, July 19. Tissue formed, but died next day.
Experiment, July 22. Tissue died next day.
Experiment, July 23. ‘Tissue died next day.
Experiment, July 25. Small masses of tissues were formed, and secreted
perisarc. They were alive 4 days after formation.
Experiment, July 27. Most of the large pieces of tissue died, but small
lumps were alive 4 days later, and ccenosarcal outgrowths had
sprouted.
Experiment, August 1. Small masses a fraction of a millimetre lived,
showed perisarc and were alive 2 days later.
Experiment, August 2. (a) Most of the tissue formed was alive on
August 38rd; much died by 7th. Outgrowths were formed, with
vertical branches by 11th, but were sickly.
Experiment, August 2. (b) Many small spheroidal masses Seeneal and
developed perisarc, but not coenosarcal outgrowths. They were
alive 5 days later.
Pennaria tiarella.
Experiment, July 26. Cell fusion and aggregation commenced at once.
Small masses formed in an hour, and fused into tissue. In about
4 hours masses 1 mm. in diameter have formed. Next day perisare
formed, and in 3 days outgrowths were developed, but at the same
time many of the larger masses died. In 5 days hydranths appeared
on the outgrowths with characteristic tentacles.
Experiment, August 3. In this experiment only stem material was used.
Fusion was rapid, and in about an hour a cake was formed. Next ~
day perisarc appeared, and outgrowths commenced. Another mass
from this culture in two days developed a hydranth. In 5 days
all masses of this experiment except 4 were dead; the survivors
developed outgrowths and were then preserved.
Many other valuable observations are included in Wilson’s paper,
but these experiments are the only ones with which we are immediately
concerned. The paper also contains a full account of the literature
on the subject of the behaviour and the regenerative properties of dis-
sociated somatic cells of various species of animals, and accordingly a
review of this literature will not be repeated here.
A STUDY OF RESTITUTION MASSES. 443
It is noteworthy that in Wilson’s experiments the restitution masses
which did not develop so far as to produce hydranths in every case died
within a few days, while in our experiments, though none of the restitu-
tion masses produced hydranths, yet many of them remained alive for
at least 60 days. Wilson does not state how long the masses which gave
rise to hydranths in his experiments remained alive.
METHODS AND TECHNIQUE.
The species used by Wilson at Beaufort N.C., U.S.A., were not avail--
able at Plymouth. The species on which most of our experiments were
carried out were Antennularia ramosa and Antennularia antennina.
Species of Tubularia, Plumularia, and Clava were also tried, but did not
give satisfactory results; though many of these produced restitution
masses from their dissociated cells, yet these masses did not remain alive
for more than a few days, and accordingly Antennularta ramosa or A.
antennina were used in all our later experiments.
All material was obtained from Plymouth Sound, inside the Break-
water.
The method of obtaining the isolated cells was the same as that em-
ployed by Wilson. Squares of bolting silk of 50, 75, and 180 meshes
to the inch were thoroughly washed and finally rinsed out in boiling
water. A good sized colony of Antennularia was then cut up into small
pieces about a quarter of an inch long and these pieces were laid in a
heap in the middle of a square of bolting silk, which was then folded over
so as to make a small bag containing the fragments of the Hydroid. This
bag was then squeezed with a pair of wooden forceps into a watch-
glass containing a little sea-water. With a quite moderate degree of
pressure the body cells of the Hydroid are forced out of the cut ends of
their protecting tubes of perisarc and then through the meshes of the
bolting silk, and by this process become separated into isolated cells
or small cell aggregates which collect as an even layer at the bottom of
the watch-glass. It is necessary that a sufficient amount of material
should be used to form a complete layer of isolated cells at the bottom
of the watch-glass about 1 mm. thick, if the formation of restitution
masses that will show any degree of subsequent development is required.
The watch-glasses containing the isolated cells were slightly shaken
and rotated so as to bring the cells together as much as possible, and then
when they had aggregated to some little degree the watch-glass was im-
mersed in a finger-bowl of sea-water. It was found advisable to place
444 W. DE MORGAN AND THE LATE G. HAROLD DREW.
the finger-bowls in troughs of running water in order to keep them cool
and at a more or less constant temperature ; before this was done a
very large mortality among the restitution masses occurred even under
the most favourable conditions, and it would seem that the temperature
of the laboratory, which is heated by hot water, was too high for these
unless some artificial method of cooling was employed.
Two kinds of water were used in the experiments: (1) that brought
from outside the Plymouth Breakwater, and (2) water circulating in
the Laboratory tanks, treated with animal charcoal and passed through
a Berkefeld filter as described by Alien and Nelson (see Journal of Marine
Biological Association, Vol. VIII, p. 432). It proved, however, immaterial
which kind of water was used. For the first day or two the water of the
cultures was changed frequently with a view to keep down the infusoria
and flagellates as much as possible ; but it is impossible to banish them
altogether, and as soon as a perisarc was well established round the
masses they were immune to attacks of protozoa. After this time the
culture water was not changed oftener than once a week. Possibly the
flagellates developed more quickly in the Berkefeld than in the outside
water,
It was found advisable to utilize the colonies of Antennularia im-
mediately after they were brought in, as by this means more vigorous
restitution masses were obtained. If the colonies were kept over night
in the ordinary tank water, in the filtered Berkefeld water, in water col-
lected from outside the Breakwater, satisfactory results were not ob-
‘tamed. In one experiment, however, excellent results were obtained
from a colony of A. antennina, which had lain for some weeks in a labora-
tory tank. The comparative greater longevity and vitality under
Laboratory conditions of the restitution masses compared to the original
colonies is very curious and difficult to explain. ;
The changes in shape and other general external developments of
the restitution masses were noted by frequently drawing under a camera
lucida : for this purpose the watch-glasses containing the cultures were
simply removed from the finger-bowls and placed on the stage of the
microscope ; after drawing they were returned to the finger-bowls with-
out disturbing the cultures.
When required for histological examination, the restitution masses
were fixed in Flemming’s fluid (strong formula). Ten minutes fixation
was found to be long enough for a moderate sized mass, say about the
size of a grain of barley ; if fixed for longer periods the cells showed a
tendency to become “ osmicated”’ and stained badly. After fixing they
A STUDY OF RESTITUTION MASSES. : 445
were washed for a few minutes in water, passed quickly up through the
alcohols to 70°%, and then washed for some hours in 70% alcohol, con-
taining a little hydrogen peroxide. After dehydration they were em-
bedded in paraffin and cut into sections 5u thick. Heidenheim’s Iron
Alum Hematoxylin, followed by Lichteriin F.S. in 70% alcohol proved
a satisfactory stain for general purposes.
Small restitution masses which were difficult to handle were sectionized
after previously mounting on a piece of amyloid liver, the mass being
made to adhere to the surface of the liver by means of a little albumen,
which was subsequently coagulated by alcohol.
THE NORMAL TISSUES WHICH, AFTER DISSOCIATION, GIVE
RISE TO THE RESTITUTION MASSES.
Antennularia ramosa is one of the Plumulariudez. It consists of shoots
which, springing from a single trunk at a certain height, divide and sub-
divide : the stems are thick and their branchlets are long and tapering,
having their internodes of equal length. The branchlets are closely set
and arranged in whorls where they come off the parent stem. The
Hydrothecze are small and campanulate in shape. Nematocysts are
present. The Gonothece are pear-shaped and single ; and have a sub-
terminal aperture facing towards the stem. In healthy specimens the
perisare is transparent and colourless, and the coenosare is of a light
yellowish green tinge.
Antennularia antennina consists of clustered stems, simple or slightly .
branched, springing from a sponge-like mass of interlacing fibres. The
branchlets are short, swollen at the base, arranged in a whorl on each
articulation of the stem. They are divided by oblique joints into inter-
nodes, which are alternately larger and smaller, the former bearing the
hydrothece. The hydrothece are small and campanulate in shape. The
Gonothece are produced singly in the axils of the branchlets ; they are
oval, with a subterminal aperture looking towards the main stem. The
perisare is transparent and colourless, and the ccenosare of a somewhat
brighter yellow colour than in the case of Antennularia ramosa.
The ccenosare of both species is hollow, and consists of a tube of
cellular tissue in the walls of which a number of smaller tubes run in the
direction of the long axis of the stem. These smaller tubes are the direct
continuations of the enteric cavities of the individual hydranths, and
are lined with cells of a type similar to those forming the hydranths.
The whole arrangement is suggestive of that in a young dicotyledonous
446 W. DE MORGAN AND THE LATE G. HAROLD DREW.
plant having a hollow stem, the enteric cavities lined with the endoderm
cells of the individual hydranths corresponding to the vascular bundles
of the plant.
A view of a cross section through a stem of Antennularia ramosa is
shown in Fig. 1. Externally it is limited by the structureless perisarc,
Fic. 1. 175.—Section of portion of normal ccenosare, showing ccenosarcal con-
tinuations of tubules continous with the enteron of individual polyps. End. tub.,
endoderm tubules; p., perisarc; ect., ectoderm cells.
within this is a somewhat indefinitely arranged mass of slightly elon-
gated cells with small but sharply staining nuclei; of these the cells in
immediate contact with the perisare are larger than the others, which
appear to be tightly packed together. At regular intervals within this
A STUDY OF RESTITUTION MASSES, 447
cell mass tubules lined with large columnar endoderm cells can be seen,
and these tubules are covered on the side where they project somewhat
into the hollow cavity of the stem with a single layer of small cubical
cells, which form a complete inner lining to the hollow stem. In longi-
tudinal sections the tubules can be traced up into the individual polyps,
and it can readily be seen that their cells are directly continuous with
the endotlerm cells lining the enteric cavity of the polyps. Similarly the
smaller cells in which these tubules are embedded in the ccenosare can
be seen to be directly continuous with the ectoderm cells of the polyps.
Neither in sections of the ccenosare nor of the polyps were we able to
distinguish any structure or structureless layer corresponding to the
mesoglea.
In Fig. 2 a tubule with surrounding ectoderm cells is shown under
a higher power of magnification. It will be noticed that the endoderm
Fic. 2. 500.—A normal tubule under higher power of magnification. Hcf., ectoderm
cells ; end. c., endoderm cells; end. tub., endoderm tubules; p., perisarc.
cells are distinctly columnar, with broad bases, and that they are con-
siderably larger than the ectoderm cells. Their nuclei are relatively
large, and usually situated near the base of the cell: the nuclear mem-
brane is sharp and well defined and the nucleoli are remarkably distinct ;
strands of chromatin are present, radiating from the nucleolus towards
the nuclear membrane. The cytoplasm is distinctly granular, and fre-
quently darkly staining vacuoles, presumably food vacuoles, were seen.
Flagella do not appear to be present on these cxnosarcal endoderm cells.
44% W. DE MORGAN AND THE LATE G. HAROLD DREW.
The smaller ectoderm cells are slightly elongated, often with pointed
ends, with the exception of those forming the layer lining the hollow of
the cxnosare, which are almost cubical in shape. The nuclei are small,
and the nucleoli relatively large and distinct.
Other structures such as the germ cells, nematocysts, etc., are not
described here as they appear to merely play the part of foreign bodies
in the restitution masses, and do not enter into their development.
THE PROCESS OF FORMATION OF RESTITUTION MASSES.
The cells that are obtained after squeezing through bolting silk of
50 meshes to the inch are, many of them, comparatively httle damaged ;
but if a finer silk is employed, such as that having 180 meshes to the inch,
the majority of the cells are crushed and broken. It would appear that
the injury caused by squeezing through a fine meshed silk is due rather
to the relatively greater pressure that must be applied to the bag con-
taining the pieces of Hydroids in order to drive the cells through the
fine meshes than to the actual size of the meshes themselves. Restitu-
tion masses that would live more than a few days, and which would show
any degree of subsequent development, were not obtained when a finer
mesh than 50 to the inch was employed, and accordingly this was most
generally employed.
An examination of the cells immediately after squeezing through a
50-mesh silk showed that the majority of them were single and isolated
from their neighbours ; small cell aggregates consisting at the most of
six or eight ectodermal cells were present, and aggregates consisting of
a smaller number of endodermal cells could be seen. These endodermal-
cell aggregates, as well as the isolated endodermal cells, were in active
motion caused by the action of their flagella : in the case of the isolated |
cells this motion consisted in progression in a number of small spirals
due to the fact that the flagella are only attached to one side of the cell.
In addition to the comparatively uninjured cells and cell aggregates,
a good deal of granular debris was present, and minute rounded bodies
which were presumably small protoplasmic masses produced by the dis-
integration of cells which had been actually crushed in the squeezing
process. Many nematocysts, some with their threads ejected, could also
be seen, and ova were often present. In some cases small pieces of the
tentacles accidentally were forced through the meshes of the silk intact ;
but these were usually visible to the naked eye, or under a low power of
magnification, and when seen were removed with fine-pointed forceps.
A STUDY OF RESTITUTION MASSES. 449
If such pieces of tentacle were not removed, and became included in
the restitution masses, it was noticed that they soon degenerate and
Fic. 3. X16.—A restitution mass 48 hours old, showing curling up of edges.
never show any sign of regeneration, and in this our observations agree
with Wilson’s.
Preparations of the freshly squeezed cells were made by fixing on a
@-- Se Pe ROe
4-@-- ee oem:
x 500.—Isolated cells, after squeezing through bolting silk of 50 mesh. Let.,
ectoderm cells ; end. c., endoderm cells ; nem., nematocyst.
Fig. 4.
slide with Acetic Sublimate Solution, and subsequent staining with
Heidenheim’s Iron Hematoxylin, followed by Lichtgriin F.S. (Fig. 4).
In such preparations both the ectodermal and endodermal cells were
easily recognizable, though the proportion of endodermal cells was
NEW SERIES.—VOL. X. NO. 3, OCTOBER, 1914, 2F
450 W. DE MORGAN AND THE LATE G. HAROLD DREW.
comparatively small compared to the number seen in unfixed prepara-
tions. This was probably due to the fact that the endodermal cells,
being kept in motion by their flagella, do not settle down on the surface
of the glass like the nonmotile ectoderm cells, and consequently do not
adhere to it on the addition of the fixative.
Examination of these preparations (Fig. 4) showed that the ectodermal
cells had mostly become rounded, their nuclei were somewhat indistinct,
and no nuclear membrane was distinguishable. The nucleoli in some
cases stained darkly, and from them a few short radiating strands of
chromatin could often be made out, but in other cases the whole nuclear
structure stained faintly and appeared as a roughly spherical mass of
indeterminate structure. The cytoplasm of these cells was clear, the
periphery often staining somewhat darker than the more central part.
Where occurring in small aggregates, the ectodermal cells appeared
comparatively uninjured, and closely resembled the normal. In the
case of the isolated cells it would seem as though the pressure to which
they had been exposed had burst the nuclear membrane and caused a
fusion of the nucleoplasm and cytoplasm.
The larger endodermal cells in these fixed preparations had lost their
columnar shape and become rounded, and their flagella were not seen.
The nuclei were indistinct and appeared as a light area in which a few
granules of chromatin could be distinguished, surrounded by the darker
cytoplasm. In most of the cells the cytoplasm had lost its granular and
vacuolated character, but in a few some darkly staining granules were
present. As might be expected from their larger size, the endoderm cells
appear to have suffered more from the squeezing process than the smaller
endoderm cells.
Interspersed between the cells all over the preparations were large
numbers of nematocysts, many of them apparently uninjured, and
sranules and globules derived from disintegrated cells and the contents
of the enteric cavities of the Hydroids.
After squeezing through bolting silk into a watch-glass containing
a little water, the isolated cells, small cell aggregates, and general debris,
which escape through the silk, soon settle down and form an even layer
of a greyish yellow colour over the bottom of the watch-glass. Within
two or three hours this layer shows a tendency to subdivide into a num-_
ber of small nodules, and after the lapse of another hour these nodules are
usually distinct elevated ageregations, often connected with one another
by fine strands which gradually become thinner and contract until they
are absorbed into the nodules from which they radiated. If left undis-
A STUDY OF RESTITUTION MASSES. 451
turbed, there seems to be no tendency for these nodules to change their
position, but if they are disturbed by shaking or rotating the watch-
glass so that they are brought into contact with one another they mutually
adhere, and in the course of some hours may give rise to one or more large
restitution masses in which no trace of the smaller nodules originally
formed can be distinguished.
Similarly if the watch-glass, immediately after the cells have been
squeezed into it, be rotated so that all the cells form a compact heap in
the centre, the restitution masses may be formed as one or more thick
flat cakes with rounded edges without the preliminary formation of the
smaller nodules described above.
THE MORPHOLOGY AND DURATION OF LIFE OF
THE RESTITUTION MASSES.
The after history of a restitution mass depends very much on its
original size when first formed, and this again depends on whether the
dissociated cells were shaken together or allowed to form the small
nodular masses already described.
When one of these larger masses of tissue is first formed it consists
res bd:
ing curling up and nodulation of edges. mass 34 days old, showing
well-marked shrinkage away
from the perisare and fe-
nestrated appearance of the
cell mass.
of a flat cake of tissue of irregular shape, sometimes adherent to the
glass. During the first 12 hours after its formation, a considerable amount
of alteration in shape occurs, the edges of the mass turn up away from the
glass, and a good deal of retraction takes place and consequently the
tissue becomes stronger and more compact. After from 12 to 18 hours
a delicate, transparent, colourless membrane is secreted round the mass,
completely enclosing it and forming a tough protecting layer: this layer
452 W. DE MORGAN AND THE LATE G. HAROLD DREW.
is evidently similar to the perisarc of the normal animal. Once this
perisarc has been secreted, the restitution mass appears to be immune
to the attacks of flagellates or bacteria, which are unable to penetrate it.
From this stage onwards the external changes that occur take place
slowly. The turned-up edges become thicker and more nodulated at the
expense of the central part, and sometimes may project in the form of
spherical or ovoid nodules connected at the base with the main mass
by a comparatively small isthmus of tissue. (In Fig. 3 a mass, 48 hours
old, is shown, and in Fig. 5 one of 8 days.) There is later a slow
but continuous shrinkage of the restitution mass away from its perisare,
leaving a clear space between the two (Fig. 6), after from three to four
weeks irregularly circular spaces begin to show in the cell mass, which
then presents a somewhat sponge-like fenestrated appearance (Fig. 6).
Later changes are extremely slow, and consist of a further slight shrink-
age, and increase in size of the spaces in the tissue. During all this time
the restitution mass retains its yellowish colour and definite outlines, and
sections show that the cells are healthy and undegenerated : in the case
of masses that die, the yellowish colour is rapidly lost, and they appear
as dirty white, soft, floccular bodies, which soon fall a prey to bacteria
and other parasites ; it is thus easy to distinguish the living from the dead
masses by the eye.
At the time of writing some of these masses have been kept alive for
a period of 60 days, and during this time none of them have shown any
tendency to regenerate a stem or hydranth.
In the case of the smaller nodular masses that had not been shaken
together so as to form larger aggregates, a perisarc was secreted in from
12 to 18 hours, and where several nodules were joined by their strands of
tissue a complete tube of perisarc was secreted around these connecting
strands. The appearance presented in such cases was often peculiar
and somewhat suggested an attempt at the formation of hydranths
which had aborted through not being able to burst the surrounding
perisarc ; but observations made from the earliest stages, when the
nodules arose from simple aggregations of the cells show that there is
no justification for such a view, and this was borne out by the internal
structure of these nodules as shown in sections of fixed preparations.
When the process of contraction of the restitution masses had proceeded
a little further, the connecting strands of tissue between individual
nodules were often completely retracted, thus leaving the nodules merely
connected by empty tubes of transparent perisarc.
A STUDY OF RESTITUTION MASSES. 453
THE HISTOLOGY OF THE RESTITUTION MASSES.
Our observations on the histology of the young restitution masses
agree closely with those of Wilson, so that it is not necessary for us to
describe the younger stages in great detail.
A section of a young restitution mass from 18 to 24 hours old shows
that a perisarc has been secreted, and that it is still in close contact with
the cell mass. The central cells are irregular, and show no trace of
stratification : the ectoderm and endoderm cells can be recognized, and
present a similar appearance to that described as seen in preparations
of the freshly squeezed cells, with the exception that the endoderm
elements were even less definite, contained no granules and were dis-
tinguishable in relatively small numbers: a few of the cells retained
their definite outlines, but others were less distinct and appeared to join
up with their neighbours by means of pseudopodia-lke processes. It
would seem probable, as Wilson suggests, that the structure throughout
is that of a cellular syncytium, and that even where the cells appear
distinct they are united by protoplasmic strands. He also remarks that
the endoderm cells form only a small fraction of the syncytium, though
they composed a very large part of the mass when fusion began. This
he explains by considering that the endoderm cells undergo a transforma-
tion which effectually precludes their recognition later, and we would
suggest that the majority of these cells take on a plasmodial character,
and so by forming a protoplasmic reticulum unite and draw together
the other elements of the mass.
The peripheral cells in contact with the perisare in these young restitu-
tion masses take on an epithelial character quite early, as might be
expected from the fact that they have secreted the perisarc. They are
distinguishable as a layer of cells resembling those forming the normal
ectoderm, with flattened bases im even contact with the perisarc, and
they are recognizable several days before any other rearrangement of the
cells is apparent in the mass.
A comparison between sections of early and later stages shows that
the nematocysts included in the masses gradually disappear and take
no part in the further development. A similar observation has been
made by Wilson.
Sections after 6 days (Fig. 7) show that the cells are much more
definite, the individual cell walls show clearly and the nuclei of the ecto-
derm cells stain distinctly ; the mass has largely lost its plasmodial indefinite
character, much of the cell debris has disappeared and the nematocysts
454 W. DE MORGAN AND THE LATE G. HAROLD DREW.
are not present or are not recognizable, and have probably been dis-
solved away. Some irregular darkly staining masses suggestive of
endodermal cells are present, but they are somewhat indefinite. The
more distinct ectoderm cells are often arranged in whorls or rows, and
Fie. 7. x 260.—Section’through part of a restitution mass 6 days old, showing indefinite
arrangement of cells. ‘The ectodermal cells are fairly well differentiated ; but
the endodermal elements, though showing a tendency towards tubule formation,
are not’well defined. The perisarc is not shown. Lct., ectoderm cells.
the external layer which secreted the perisarc is well defined. The im-
pression conveyed by examination of sections at this stage is that some
process of rearrangement has been initiated among the cells, but there
is little to show what may be expected to be the result of this rearrange-
ment. No mitoses were observed.
Seven days later development has proceeded much further, many cells
definitely of the endodermal type are present, and they contain numbers
of small granules in their cytoplasm. These cells are often arranged so
as to form distinct tubules, each having a definite lumen and closely re-
sembling in structure the ccenosarcal part of the enteron of an individual
polyp. In other places the endodermal cells are arranged in rows, in
irregular masses, or singly, embedded among the ectodermal cells. Where
formed, the tubules are always in any one section cut transversely, longi-
tudinally, and at intermediate angles, hence they must be irregularly
coiled and crossed within the mass. At this stage the ectodermal cells
A STUDY OF RESTITUTION MASSES. 455
are sharp and distinct, approximating the normal in size but slightly
larger; they have a tendency to be fusiform in shape with sharply
pointed extremities, and are often joined end to end. Spaces between the
cells are frequent, but they are occasionally found arranged in compact
whorls or masses. The outline of the cells is well defined, the cytoplasm
clear but slightly vacuolated, the nuclear membrane and nucleolus dis-
tinct.
Sections of restitution masses at the end of 3 weeks (Fig. 8)
showed a still more definite arrangement of convoluted endodermal
Fie. 8. x 260.—Section through part of a restitution mass 20 days old, showing forma-
tion of definite endodermal tubules; all the cells in the mass are sharp and well
defined, and the plasmodial character noticeable in earlier stages is lost. Lct.,
ectoderm cells ; end. tub., endoderm tubules; p., perisare.
tubules. The cells forming these tubules were regularly arranged and
closely resembled those lining the enteric cavity of the normal polyp
with the exception that no flagella were seen. The cytoplasm of
these cells was crowded with large granules, which were often so plentiful
as to partially obscure the nucleus. The ectoderm cells were present in
even smaller numbers than in earlier stages, but were very definite in
structure. Occasional large spaces, corresponding to the spaces producing
the fenestrated appearance described as occurring in older masses, were
seen among the cells, and other areas in which the cells had degenerated
and left merely some granular debris were observed.
At the end of 5 weeks (Fig. 9) the endodermal cells forming the
tubules had become crowded with darkly staining spherical granules of
456 W. DE MORGAN AND THE LATE G. HAROLD DREW.
varying size, often totally obscuring the nucleus, and the ectoderm cells
often partially or completely surrounded the tubules in the form of a
well-defined single cell layer. In some cases the cells of the tubules had
apparently undergone autolysis, and a space containing a little granular
cell debris was left surrounded by the ectodermal layer.
Later the stages show little change or further degeneration. Sections
after 50 days show that a large proportion of the endodermal cells are
crowded with granules, and many of the tubules have disappeared ; on
the other hand, the ectoderm cells are quite undegenerated. At the
time of writing such restitution masses have been kept alive and in
apparent health for 60 days.
Fic. 9. 260.—Section through a small restitution mass 35 days old, showing the
formation of many granules in the endoderm cells. Some of these cells are break-
ing down, so that the tubules are less distinct. The ectoderm cells remain healthy.
Eet., ectoderm cells ; end. tub., endoderm tubules; gr., cytoplasmic granules.
No signs of mitosis or any form of cell division was observed in any
stage.
We would suggest that the changes that take place may be explained
as follows :—
The endoderm cells are considerably more damaged in the process
of squeezing through the bolting silk than the smaller and tougher
ectoderm cells. They lose the majority of their cytoplasmic granules,
which are probably in the nature of a digestive ferment, and the nuclear
membrane is usually ruptured, causing certain changes in the nuclear
structure. As the cells begin to form aggregates the endoderm cells
become diffuse and join with each other by means of protoplasmic pro-
cesses to form a plasmodium, in the midst of which the comparatively
uninjured ectoderm cells are embedded. Certain ectoderm cells make
their way towards the periphery of the mass, or are left there by the
~
A STUDY OF RESTITUTION MASSES. 457
contraction of the plasmodium away from them, and secrete a perisarc
within 12 or 18 hours. This resumption of function in so short a time
and the localization of the secreting power so that secretion of perisarc
takes place only on the outside of the mass, is somewhat remarkable,
considering that all the normal relationships between the cells must have
been completely upset. Contraction of the plasmodium of endoderm cells
still continues, eventually causing the mass to contract away from the
perisare, and it is noteworthy that when this occurs no fresh perisare is
secreted by the peripheral cells. IH, however, a small piece of the perisare
is removed, it is rapidly re-secreted by the cells in the neighbourhood, and
the gap is healed. From this it would seem possible that the secretion
of perisare is a direct reaction of the ectoderm cells when in contact with
sea-water, and that it is not produced when they are in contact with the
fluid filling the space between the shrunken mass and the perisarc, and
that accordingly this fluid has a different constitution to sea-water.
During the retraction of the plasmodium, the endodermal cells gather
together their ramifying processes and again become differentiated, and
so very slowly resume their normal form. Of the manner in which many of
them become collected so as to form definite tubules, we are unable to
offer any explanation. The appearance of sections at a period when
the earliest stages of tubule formation are apparent suggests that the
plasmodial masses, which will later develop into endodermal tubules,
become arranged and segregated before they have differentiated into
recognizable endoderm cells, but this is the merest surmise. In cases like
this, where individual cells cannot be watched through their modifica-
tions and development, the value of the evidence of sections of different
masses is always doubtful. Considering that no sign of cell division was
ever seen in our experiments it would seem strongly probable that a
certain amount of actual migration and rearrangement of the cells
within the masses must occur, but no clue is given as to the form or
mode of action of the forces causing this rearrangement. As in the
case of Wilson’s experiments, however, it is difficult to imagine any
“ form regulation ” force coming into play after isolation and subsequent
agelomeration of the individual cells forming the original organism.
We consider that the granules found in the cytoplasm of the endodermal
cells in the older restitution masses are probably in the nature of the pro-
enzyme of the digestive ferment. Since the tubules are closed, and there is
no food stimulus, the granules are not discharged, but accumulate in the
cell up to a certain limit; when this is reached the cell ruptures and
autolysis ensues. From the fact that these granules are formed, It
458 W. DE MORGAN AND THE LATE G. HAROLD DREW.
follows that a certain amount of active metabolism is going on within the
mass, and from the disappearance of the cell debris, nematocysts, ova,
etc., which are included in the restitution masses when first formed, it
would seem at least possible that these may be absorbed and used up in
the metabolic processes of the living cells. Similarly the living cells may
feed on those which degenerate.
SYNOPSIS OF EXPERIMENTS.
Numbers omitted belong to experiments not dealt with in this paper.
Experiment 1.—A colony of Antennularia antennina dredged on
5th December, 1911, was allowed to stand through the night in “ out-
side ” water, and at 10 a.m. on 6th was squeezed into watch-glasses con-
taining a little Berkefeld water, through 50 mesh bolting silk.
Aggregation commenced about 12 noon, and the watch-glasses were
then placed in finger-bowls of Berkefeld water. Under the microscope
no direct motion of the cells towards one another was noticeable. The
cells gravitated downwards and adhered together to form small spherical
nodules. These were shaken towards the centre of the watch-glass and
left for the night.
On the morning of the 7th nearly all the stuff had united to form
irregularly shaped plates from 1 to 2 mm. in length connected by narrow
strands. In various spots there were club-headed vertical upgrowths
from the plates. The whole aggregate, which was greenish yellow in
colour, was surrounded with a tough perisarc, no space appearing between
it and the contents.
By the 8th considerable contraction of the interior mass was noticed.
There was a clear space between the perisare and the contained matter,
and clear spots were seen here and there in the plates. The contents of
the club-headed upgrowths also contracted.
On the 9th these cultures were found swarming with Infusoria and
Flagellates, and they were fixed in Corr. Sub. It was thought then that
Protozoa would injure the culture ; experience proved that they are not
harmful.
Experiment 3.—Colonies of Antennularia antennina collected on
12th December, 1911, and kept 24 hours in Berkefeld water. Squeezed
through 180 mesh bolting silk, 11 a.m., December. 13th. By 3 p.m.
small spherical masses had formed. On the 14th no change had occurred,
the small spheres forming a film over the bottom of the watch-glass.
Microscopical examination showed cells with a broken outline ; and small
A STUDY OF RESTITUTION MASSES. 459
fragments, which might be portions of larger cells. This may very
possibly result from pressure through such a small mesh as 180. This
experiment gave no further results.
Experiment 4.—14th December. Squeezed a colony of Antennularia
antennina that had lain for some weeks in a wooden tank in the Labora-
tory, through 50 mesh. No attempt at aggregation. Very probably
the material had deteriorated.
Experiment 5.—19th December, 1911. Colonies of Antennularia
antennina brought in from the Sound. Very dirty, and placed for the
night in Berkefeld water. On 20th noon squeezed through 50-mesh bolting
silk into watch-glasses. By 4.30 p.m. small masses had formed, mostly
vertical to the bottom of the glass, but so far the cells not very coherent.
By noon on the 21st numerous small masses surrounded with perisare
adherent to the glass.
Many of these masses gradually died off, without showing any marked
change in shape. The contents, however, gradually contracted away
from the perisarc, and finally died. Two small masses were alive on
20th January, 1912, 34 days from the commencement of the experiment.
These were fixed for sectioning.
Experiment 8.—28th December. Colony of Antennularia ramosa
squeezed through 50 mesh at 5 p.m. into outside water. By 11 a.m.,
29th, many large masses formed, and adhering to the glass. On 30th the
perisarc clearly defined, and the interior plasm slightly contracted away
from it. These masses lived until 5th January, 1912, when they died.
Experiment 10.—12th January, 1912, 4 p.m, A very fine colony of
Antennularia ramosa squeezed through 50 mesh into watch-glasses which
were placed in bowls of outside water. A larger amount of material was
used in this and subsequent cultures.
By 13th three large masses, between 3 and 4 mm. in length, had formed.
They had not adhered to the glass, and the edges were rounded and
turned over, somewhat resembling the helix of the human ear. The
surface smooth, showing that perisare had formed, and colour the charac-
teristic yellowish green.
As time went on there was considerable contraction, and the edges
became thicker. The cells appeared to migrate from the centre towards
the edges, so leaving a thin central nearly clear plate, surrounded by
thickened ridges. There was no sign of proliferation or budding of any
kind, and by the 24th all three had lost the yellow colour, and looked
grey and unhealthy. They were then fixed.
460 W. DE MORGAN AND THE LATE G. HAROLD DREW.
Experiment 13.—17th January, 1912, 4. p.m. Flourishing colony of
Antennularia ramosa squeezed through 50 mesh and 180 mesh into watch-
glasses. Allowed to settle for 3 hours, and then transferred to bowls of
Berkefeld water.
18th, 10 a.m. All the 50-mesh cultures show typical lobate masses,
but of smaller size than in Exp. 10. The masses from 180 mesh are
smaller and lighter coloured. Pieces of tentacle and theca were observed,
and removed. Small masses from each culture placed in finger-bowls
containing about 450 c.c. Berkefeld water.
19th. All masses from 50 mesh have contracted greatly, and in-
creased in length vertically. They are generally conical. In places
the perisarc not formed. Colour, a healthy yellow. All adhered to
the glass.
The culture from 180 mesh differs from above. Only small spherical
masses have resulted, generally adhering to the glass. Perisarc has not
yet been formed.
20th. Most of the masses have contracted further, but the majority
are grey and unhealthy looking.
It may be noted that the Laboratory was particularly warm at this
time, and the cultures were affected thereby.
24th. Most of the masses were dead, one or two remained alive until
31st. They showed no great change except contraction of the interior
protoplasm away from the perisare and slight attempts to form knobs
or proliferations. These did not advance far, and the plasm soon con-
tracted away from the surrounding perisarc. Certain of the masses were
fixed for examination.
Experiment 15.—25th January, 1912. Antennularia ramosa squeezed
through 50 mesh and Antennularia antennina through 180 mesh. Allowed
to settle-through the day. ;
26th. The 180-mesh culture has simply formed a film over the bottom
of the glass—no masses have formed.
Numerous yellowish masses in the 50-mesh culture. Certain of these
were transferred to finger-bowls of “ outside’ water. Generally they
were not healthy in appearance, and a good deal of foreign matter was
mixed with them.
28th. One mass remains healthy. Several lobes appear on it. The
perisare has formed, but is rougher than usual. A great many Infusoria
in the cultures.
29th. The lobes have contracted into the main mass, which has also
further contracted.
A STUDY OF RESTITUTION MASSES. 461
Ist February. Still healthy in appearance. The contents have
further contracted away from the perisarc. Fixed for examin-
ation.
Experiment 17.—31st January, 1912, noon. Squeezed colonies of
Antennularia ramosa through 50 mesh, and placed in finger-bowls of
Berkefeld water, 4p.m. The temperature of the Laboratory is so high that
these bowls were placed in a trough of running water.
lst February. Lobate masses, 1 to 2 mm. in length, surrounded by
perisare have formed.
2nd. The lobes have further contracted, and most of the masses are
attached to the glass.
2nd to 11th. Very little change observable except slight contraction
by which a space was left between the contents and the perisare. Clearer
spaces appeared also in the body of the mass.
20th. One mass now 20 days old and thoroughly healthy in appear-
ance fixed.
21st. Several small masses still alive. In the largest of them con-
traction of the contents at various points has resulted in a markedly
spongy appearance, as shown in the figure. This is observable in a less
degree in other smaller masses.
9th March. All remained alive up to this date, and without any
apparent change. From this date onward the contents appear to be
gradually degenerating—in one or two of the masses the enclosing perisare
is almost empty.
21st. The spongy appearance of the large mass is gradually changing,
and the contents appear to be concentrating in the centre. This culture is
now 51 days old, and has still a healthy yellow colour. Similar concen-
tration has taken place in one or two of the smaller masses which were
fixed for examination.
Experiment 23.—1st March, 1912, 11 a.m. Squeezed fine colonies of
Antennularia ramosa through 50 mesh. Aggregation of cells commenced
almost immediately.
3rd. Of the three cultures made on the Ist, two are not healthy.
Spherical masses have formed, but they look soft and flocculent, and the
perisarc is not clear and smooth.
The third culture, however, has resulted in a healthy lobed mass, not
attached to the glass—deep yellow in colour and with a smooth perisare.
The edges of this mass are folded over into knobbed ridges, round a
thinner central plate. There is a nearly vertical cylindrical mass at
one end.
462 W. DE MORGAN AND THE LATE G. HAROLD DREW,
13th. The edges have curled over more, and ten knobs on them are
more accentuated. The centre plate thinner, and at points clear spaces
appear.
15th. Cut off the end of the vertical projection.
16th. Perisarc had reformed round the cut end and the incised
piece.
SUMMARY AND CONCLUSION.
1. The Hydroids experimented on were Antennularia ramosa, and A.
antennina.
2. These were cut in pieces and pressed through bolting silk, with the
result that isolated cells and small cell aggregates were obtained,
which soon aggregated together to form compact masses.
3. These restitution masses secreted a perisare within from 12 to 18
hours.
4. Various changes in shape, and general retraction of the mass away
from the perisare occurred later, but even up to 60 days there was
no sign of the regeneration of the hydranths.
5. The restitution masses consisted of ectoderm and endoderm cells,
and in addition such structures as nematocysts, ova, and broken
down cells, all of which were subsequently absorbed and played no
part in the future development. The ectoderm cells were relatively
little damaged, and were embedded in a plasmodial mass formed
by the endoderm cells,
6. A definite layer of ectoderm cells is formed on the surface, and these
cells secrete the perisarc.
7. Gradual aggregation and segregation of the endoderm cells from the
plasmodial mass takes place ; and they form very definite tubules
similar in structure to the ccenosarcal tubules continuous with the
enteric cavities of the normal hydranths. These tubules are em-
bedded in a mass of ectoderm cells, they are convoluted and ramify
in all directions. Many granules develop in the cytoplasm of these
cells, and after about a month many of them have degenerated.
(o)
_ The ectodermal cells show no signs of degeneration, and the masses
containing them have been kept alive for 60 days at the time of
writing.
9. In none of the experiments was there any sign of the occurrence of
cell division.
A STUDY OF RESTITUTION MASSES. 463
In conclusion, we can say that, experimenting on different species of
Hydroids to those employed by Wilson, we have confirmed his results
up to the stage of development at which the restitution mass is formed
and the perisare secreted. Beyond that our results differ ; in the species
used by Wilson the restitution masses soon gave rise to hydranths, and
practically complete new Hydroids were regenerated ; in the species
of Antennularia used by us development of the restitution masses was
much slower ; they never regenerated hydranths, but gave rise to tumour-
like masses of convoluted tubules lined with endodermal cells embedded
in masses of irregularly arranged ectoderm cells. These masses remained
alive for at least 60 days.
Our experiments have resulted in the production of masses that are
certainly abnormal and pathological, but nevertheless we would submit
that the segregation and rearrangement of the cells after isolation, and
the comparatively long duration of life of the tumour-like masses to which
they give rise are facts of considerable theoretical interest.
PLYMOUTH,
March 28th, 1912.
[ 464 J
On F, Echinus Hybrids.
>
IV
J
H. M. Fuchs.
AN investigation on inheritance in hybrids between the three English
species of Hchinus was carried out in the Marine Biological Laboratory;
Plymouth, during 1909-1912 by C. Shearer, W. de Morgan, and H. M.
Fuchs. In a paper published in the Phil. Trans. Royal Soc., Ser. B,
Vol. CCIV., p. 255, the results of this work were described in detail. At
the time of publication, E. miliaris had been raised from the egg to
maturity in the laboratory, in the course of one year, and a second
generation had been obtained from these individuals, but none of the
hybrid urchins had as yet reached maturity. This year, however, some
of the hybrids have become sexually mature, and from them a second
hybrid generation has been raised.
The urchins which have formed ripe genital products are four in-
dividuals of the cross FH. esculentus 2 X E. acutus 3 (referred to below as
EA), derived from fertilizations made in 1912. The largest of these
urchins now measures 6 cm. in diameter, exclusive of the spines. On
May 11th, 1914, two of these hybrids laid eggs in the tank in which they
were kept. Naturally these eggs could not be used for experimental
purposes, since they were deposited in the sea-water of the aquarium
circulation, and therefore not under sterile conditions. On June 6th
I induced three of the four to deposit genital products without cutting them
open, under conditions which excluded the possible presence of foreign
eggs or spermatozoa. It is hardly necessary to mention here that, as in
all the previous work on Echinus hybrids, the fact of the comp!ete absence
of such sperm was made certain by controls of unfertilized eggs, none of
which segmented. Two of the three hybrids from which genital products
were obtained proved to be females and one a male. The sperm from the
latter gave 100° fertilizations with the eggs of the former, yielding
healthy larve.
From this it is seen that hybrids between the species EZ. esculentus and
FE. acutus are perfectly fertile and that a healthy F, generation can be
obtained from them. When a larger number of these F’, hybrids have been
ON F, ECHINUS HYBRIDS. 465
reared, an examination of the characters of the fully grown urchins
should decide whether the intermediate forms between the two species,
which are found in the sea and which are quite fertile, are to be con-
sidered as hybrids or as extreme variants of one of the two species.
Besides making the cultures described above, I fertilized E. miliaris
eggs with the sperm of the HA male, and used EH. miliaris sperm to
fertilize HA eggs. This was done in order to see whether the inheritance
of the late larval characters (posterior epaulettes and green pigment)
in these crosses would be the same as when pure F. esculentus or EH. acutus
was crossed with #. miliaris. Now, twenty-one cultures,* derived from
fifteen fertilizations, have shown that the inheritance of these larval
characters has this year been the same as it was in 1912: the H. escu-
lentus or E. acutus characters are developed in the hybrids in both
reciprocal crosses with H. miliaris. 1¢ was found that the two reciprocal
combinations of HA X miliaris likewise gave this result. From the cross
EA ? X miliaris 3 large numbers of vigorous fully formed plutei de-
veloped, and a number of these “ triple-hybrids ” have already passed
through metamorphosis.
Unfortunately the F, generation obtained from the £. esculentus X
E. acutus hybrids can give no information as to the inheritance of the
late larval characters, since the latter are alike in the two species. It is
the F, generation from hybrids between £. esculentus or HE. acutus and
E. miliaris that will give this valuable information, but none of these
hybrids have as yet reached maturity. A small number of E. miliaris 2
X E. acutus 3 hybrids (of which the largest measured 24 cm. in diameter,
exclusive of spines), from fertilizations made in May, 1912, were alive and
healthy this summer. After having tried unsuccessfully to mduce these
to deposit eggs or sperm, I cut them open on June 6th of this year. They
contained, however, only small and quite immature gonads.
As it must be some time before more FL. acutus (or FH. esculentus) X
E. miliaris hybrids will have grown large enough to be mature, I wish
to record these results up to date. The success in bringing the HA
hybrids to maturity has been largely due to the care taken by Mr. A. J.
Smith, head assistant at the Plymouth Laboratory, in attending to the
cultures after metamorphosis. The investigation was made with the
assistance of a grant from the Royal Society.
* Some of these cultures were reared at Plymouth, others were transported as blastule
to the Imperial College, London, and raised there in water which came from Lowestoft.
NEW SERIES.—VOL. x. NO. 3. OCTOBER, 1914. ; 2G
[ 466 }
The Trematode Parasites of Fishes from the
English Channel.
By
William Nicoll, M.A., D.Sc., M.D.
With Figures 1-6 in the Text.
In continuation of my researches on the entozoa of British marine fishes
I spent two months (August and September, 1909) at the Plymouth
Marine Biological Station. By the courtesy of the Government Grant
Committee of the Royal Society, a table was placed at my disposal and
all expenses in connection with the investigation were defrayed.
Hitherto few observations have been made upon entozoa from fishes
of the south coast. The area, however, is of considerable interest from
a faunistic point of view, for it contains several species of fish which
are uncommon or unknown on other parts of our coast. In addition it
is richer in species than either the east or the west coast. The influx
of Mediterranean forms adds further interest.
During the course of these two months 419 fish belonging to 70 species
were examined. Later, further consignments were sent to me in London.
These comprised an additional 56 fish with an additional 9 species. The
total number with which this investigation deals is therefore 475 fish
and 79 different species. Amongst these, Acanthopterygian fishes
figured most largely. The various groups were represented as follows :—
Species. Fishes.
Acanthopterygii ; : : Ray 213
Pharyngognathi : ; : Sy 50
Anacanthini. : : : 5.20 109
Physostomi 5 21
Lophobranchii . 4 31
Elasmobranchii 12 51
Total : : on) 475
Amongst these 79 species there were 37 which I had not previously had
an opportunity of examining, and the majority of them afforded interest-
ing new records.
THE TREMATODE PARASITES OF FISHES. 467
Judging by those figures this is probably the largest and most repre-
sentative investigation which has hitherto been made on this subject. A
comparison with the numbers dealt with in my previous reports will
perhaps be of interest. For St. Andrews, Millport, and Aberdeen the
corresponding figures are as follows :—
St. Andrews.* Millport. Aberdeen. Total.
Species. Fishes. Species. Fishes. Species. Fishes. Species. Fishes
Acanthopterygu. 16 74 #11 34 7 e308 2) 246 kas
Pharyngognathi. 0 0 2 a 0 0 2 fi
Anacanthini =f tae GD ie al 1S: 46.) P5235 45 tee
Physostom1 ac 50 3 8 3 4 8 62
Lophobranchi* . 2 2 2 2 0 0 3 t
Elasmobranchi . 3 5 2 2 0 0 5 C
Total Pee AGE ok OL te. SO bbeer ar0
From this it is evident that the material examined at Plymouth was
richer, not only in the gross total examined, but also in the variety of
specimens, than the corresponding material from the other three localities
combined. Of the individual groups only the Anacanthini and Physos-
tomi were not so well represented at Plymouth as in these other localities.
In these four series of investigations I have thus examined a total of
845 fish belonging to 102 different species, giving an average of a little
over 8 fish of every species. Some specimens have naturally received
more attention than others, and those most exhaustively dealt with
have been the sprat (Clupea sprattus), the common dab (Pleuronectes li-
manda), Lepadogaster gouann, Ammodytes tobvanus, the mackerel (Scom-
ber scombrus), and the butter fish (Centronotus gunnellus). Other fishes
which have received a large measure of attention have been the horse-
mackerel, the sea bream, the whiting, and the John Dory.
From these four localities the aggregate figures are :—
Species. Fishes.
Acanthopterygi. : : oO 351
Pharyngognathi_ . ; ; 2D 50
Anacanthini . : 4 : 2S 261
Physostomi . ; : : Zips 90
Lophobranchii* : ; oe 35
Elasmobranchii.. : 5 wale 58
Total. : . 102 845
* The Sun-fish (J/ola molw) is included here,
468 WILLIAM NICOLL.
These 102 species represent practically all the marine fishes commonly
occurring in British seas. Little more than 20 others have ever been re-
corded from the British coasts, and the majority of those only as isolated
individuals.
Apart from these investigations only four species have been recorded
in British waters as hosts of trematode parasites, namely, Brama rai,
Phycis blennoides, Rava radiata, and Trygon pastinacea.
In addition to the four above-mentioned localities, the trematode
parasites of marine fishes have been pretty exhaustively dealt with on
the Northumberland coast by Miss Lebour and on the Lancashire coast
by Johnstone and A. Scott. From these investigations a fairly compre-
hensive idea may be obtained of the trematode fauna inhabiting our
marine fishes. It seems desirable, however, that further investigations
should be made in such areas as the Bristol Channel, the north-west
coast of Scotland, or the Hebrides, and the southern part of the North
Sea (e.g. off Lowestoft). In particular it would be interesting to obtain
information as to the trematode fauna of fishes from the coast of Ireland,
a region still practically untouched.
Of the 475 fishes examined at Plymouth, 380 (80°) were infected with
parasitic worms: 56% were infected with Trematodes, 44% with Ces-
todes, 48°% with Nematodes, and 2°% with Echinorhynchs.
It is interesting to compare these figures with those obtained in other
areas. The comparison is shown in the following table :—
Trematodes. Cestodes. Nematodes. Echinorhynchs. Total.
St. Andrews . 75% 54% 67% 8% 83%
Millport 10, 46% 76% 138% 80%
Aberdeen Bei) ay 5T% 58% 4% ot,
Plymouth > 90%; 44% 48% 2% 80%
Total ..°. ~ 760%, 47% 56% 5% BLE
This table shows that although the percentage of infected fishes in
the Plymouth area is only slightly less than that in the other areas, yet
the variety of parasites in each fish is considerably less. It will be seen
that the Plymouth figures are less in every case than those of other
areas with the single exception of the incidence of Trematodes in the
Aberdeen fishes. A
In the present report only the trematode parasites are dealt with.
Over 50 different species were collected, and these represent about
three-fifths of the total number of Trematodes known to occur in British
THE TREMATODE PARASITES OF FISHES. 469.
marine fishes. The most interesting of these have already been described
in a previous paper (Nicoll, 1913a).
At the end of this report a list is given of the fishes examined at
Plymouth, with the trematode parasites which were obtained from
them.
I have to thank Dr. E. J. Allen, Director of the Plymouth Marine
Laboratory and his assistant, Mr. A. J. Smith, for their unfailing courtesy
and help.
LIST OF SPECIES DEALT WITH IN THIS REPORT.
DIGENEA.
DISTOMATA PROSOSTOMATA.
Family ALLOCREADITIDAE.
Sub-Family ALLOCREADIINAE.
Genus Podocotyle (Dujardin).
1. P. atomon (Rud.).
2. P. reflexa (Crepl.).
3. P. syngnathi Nicoll.
4. P. atherinae sp. nq.
Genus Lebouria Nicoll.
5. JL. varia Nicoll.
6. JL. alacris (Looss).
Genus Peracreadium Nicoll.
7. P. genu (Olsson).
8. P. commune (Olsson).
Genus Cainocreadium Nicoll,
9. C. labracis (Dujardin).
Genus Helicometra Odhner,
10. H. pulchella (Rud.).
Sub-Family STEPHANOCHASMINAE.
Genus Stephanochasmus Looss.
11. S. pristis (Deslongch).
12. SS. caducus Looss, var. lusct.
13. 8S. cesticillus (Molin).
470 WILLIAM NICOLL.
Sub-Family LEPOCREADIINAE.
Genus Lepidapedon Stafford.
14. ZL. rachion (Cobbold),
Genus Pharyngora Lebour.
15. P. bacillaris (Molin).
Genus Lepidauchen Nicoll.
16. L. stenostoma Nicoll.
Family FELLODISTOMIDAE.
Sub-Family FELLODISTOMINAE.
Genus Steringotrema Odhner.
17. 4S. cluthense (Nicoll).
18. 8S. divergens (Rud.).
19. 8S. pagelle (v. Ben.).
Genus Bacciger n.g.
20. B. bacciger (Rud.).
Sub-Family HapLocLaDINaeE.
Genus Tergestia Stossich.
21. T. laticollis (Rud.).
Family ZOOGONIDAE.
Sub-Family ZooGoniIna£.
Genus Zoogonoides Odhner.
22. Z. viviparus (Olsson).
Genus Zoonogenus Nicoll.
23. Z. vividus Nicoll.
Family MONORCHIDAE.
Sub-Family MoNnorcHINae.
Genus Monorchis (Monticelli).
24. M. monorchis (Stossich).
Family HAPLOPORIDAE.
Genus Haploporus Looss.
25. H. benedeni (Stossich).
THE TREMATODE PARASITES OF FISHES.
Genus Saccocoelium Looss.
26. S. obesum Looss.
Family AZYGIIDAE.
Genus Ptychogonimus Liihe.
27. P. megastomus (Rud.).
Family HEMIURIDAE.
Sub-Family HemrurrNae.
Genus Hemiurus Rud.
28. H. communis Odhner.
29. H. ocreatus (Rud.).
-Sub-Family Drnurinae.
Genus Lecithocladium Liihe.
30. L. excisum (Rud.).
Sub-Family STERRHURINAE.
Genus Lecithochirium Liihe,
31. L. rufoviride (Rud.).
Genus Synaptobothrium (v. Linstow).
32. S. caudiporum (Rud.).
Sub-Family LecirHasTERINAE.
Genus Lecithaster Luhe.
33. L. gibbosus (Rud.).
Sub-Family SyNCOELIINAE.
Genus Derogenes Liihe.
34. D. varicus (Miillez),
Genus Hemipera Nicoll.
35. H. ovocaudata Nicoll.
Genus Derogenoides Nicoll.
36. D. ovacutus Nicoll.
Family (BUNODERIDAE).
Genus Bunodera Railliet.
37. B. nodulosa (Zeder).
ATI
472 WILLIAM NICOLL.
Family (ACANTHOCHASMIDAE).
Genus Acanthochasmus Looss.
38. A. imbutiformis (Molin).
DISTOMATA GASTEROSTOMATA.
Family BUCEPHALIDAE.
Sub-Family BucEPHALINAE.
Genus Bucephalus Baer.
39. B. minimus (Stossich)
Genus Bucephalopsis (Diesing).
40. B. gracilescens (Rud.).
Genus Rhipidocotyle Diesing.
41, R. minima (Wagener)
42. R. viperae (v. Ben.).
Sub-Family PRosoRHYNCHINAE.
Genus Prosorhynchus (Odhner).
43. P. crucibulum (Rud.).
44. P. aculeatus Odhner.
45. P. triglae sp. inq.
46. P. squamatus Odhner.
MONOGENEA.
Genus Microcotyle v. Ben. & Hesse.
47. M. draconis Briot.
Genus Axine Abildgaard.
48. A. belones Abildg.
Genus Octobothrium F. S. Leuckart.
49. O. merlangi (Kuhn).
Genus Octocotyle Diesing.
50. O. scombri Kuhn.
THE TREMATODE PARASITES OF FISHES. 473
Genus Pseudocotyle v. Ben. & Hesse,
51. P. squatinae v. Ben. & Hesse.
Genus Calicotyle Diesing.
52. C. kroyert Diesing.
DIGENEA.
DISTOMATA PROSOSTOMATA.
Family ALLOCREADIIDAE.
Sub-Family ALLOCREADIINAE.
Genus PODOCOTYLE (Dujardin).
Podocotyle atomon (Rud.).
Odhner, 1905, pp. 320-6.
Lebour, 1908, pp. 26-27.
This parasite was obtained from ten species of fish, namely, Gobius
ruthensparri, Centronotus gunnellus, Cottus bubalis, Cyclogaster montagua,
Gastraea spinachia, Gadus merlangus, Pleuronectes flesus, Zeugopterus nor-
vegicus, Nerophis aequoreus, and Anguilla vulgaris. This is the first record
of its occurrence in the pipe-fish (Nerophis).
Podocotyle reflexa (Creplin).
Odhner, 1905, p. 326.
This species was obtained from the intestine of Gastraea spinachia and.
Onos mustela on several occasions. It is distinguished from the previous
species by its much longer cirrus-pouch and the interrupted arrangement
of its yolk glands. The limits fixed by Odhner for the size of this species
are too narrow, aS mature specimens little over 1 mm. in length were
found in Onos mustela. It is extremely difficult to differentiate such small
specimens from P. atomon. |
Podocotyle syngnathi Nicoll.
Nicoll, 1913a, pp. 238-40.
This species was frequently found in the pipe-fishes, Syngnathus acus,
Siphonostoma typhle and Nerophis aequoreus,
474 WILLIAM NICOLL.
(Podocotyle) atherinae sp. ing. (Fig. 1).
A single specimen of a species of “ Podocotyle ’’ was obtained from the
anterior part of the intestine of Atherina presbyter. J am unable to refer
it to any known species, and it is doubtful even if it can be included in
the genus Podocotyle. It is a small, somewhat flattened form measuring
1-1 mm. in length by -49 mm. in greatest breadth, and it is of a dark
orey colour in life. The outline is roughly oval with a slightly attenuated
neck.
The oral sucker is globular with a diameter of -13 mm. The ventral
sucker is transversely oval and measures :21-28 mm. The latter is
CB.--
KSt.:
ma, tnt FO* sere
~*~,
° eosin § ee
°
o%r 08
oe
Fic. 1.—(Podocotyle) atherinae. Ventral view x 50. C.B. Cirrus-pouch ; K.St. Ovary ;
P.G. Genital aperture; R.S. Receptaculum seminis; T. Testes. G. Hoberts del.
situated -46 mm. from the anterior end. The pharynx is contiguous with
the oral sucker and has a diameter of 07 mm. The cesophagus is -11 mm.
long, and the wide diverticula extend nearly to the posterior end of
the body.
The genital aperture is on the left side a little in front of the level of
the intestinal bifurcation. The cirrus-pouch is long and slender, and
reaches to the level of the ovary. It contains a long, convoluted vesicula
seminalis. The ductus is simple. The testes lie near the posterior end
of the body. The distance between the posterior testis and the tip of
the tail being -13 mm. They are contiguous and oblique, the anterior
being on the left. Their outline is irregularly globular, and their margins
are entire. The posterior testis lies closely apposed to the right intestinal
diverticulum, while the anterior one is apposed to the left diverticulum.
Their greatest diameter is about -17 mm.
THE TREMATODE PARASITES OF FISHES. 475
The ovary lies to the right of the anterior testis and a little in advance
of it, the two being almost contiguous. It is a distinctly trilobate body,
the lobes being directed backwards, and its greatest diameter is -13 mm.
It is separated from the ventral sucker by a space of -14 mm. The
medium-sized, pear-shaped receptaculum seminis lies immediately in
front of the anterior testis. The yolk glands are moderately developed.
They are almost entirely marginal, their anterior limit being the level of
the ventral sucker. They fill up a considerable part of the post-testicular
space, but do not unite. Behind the ovary a few follicles are found on
the inner side of the right intestinal diverticulum, while on the left a few
are found internal to the diverticulum on the level of the posterior testis.
The scanty ova measure -069—-072 x -036 mm., and are provided with a
minute knob-like process at their anopercular pole.
In referring this form to the genus Podocotyle rather than to any of
the other genera of the sub-family one is influenced by the characteristic
shape of the ovary, the position of the genital aperture and the length
of the cirrus-pouch. The position of the testes is the chief contradictory
feature, and in this respect the species bears a closer resemblance to
Lebouria. It might be suggested that it is an abnormal specimen of
P. atomon in which the testes have become displaced, but as I have no
previous experience of such an abnormality I am very doubtful if this
could be the case.
Genus LEBOURIA Nicoll.
Lebouria alacris (Looss),
Nicoll, 1910, pp. 332-4.
This species was frequently obtained from the smaller Labridae
(Ctenolabrus rupestrissCentrolabrus exoletus and Crenilabrus melops). A
single specimen was also found in the intestine of Labrus berggylta.
Lebouria varia Nicoll.
Nicoll, 1910, pp. 329-32.
This species was only met with in the dragonet (Callionymus lyra), in
which it is fairly common.
Genus PERACREADIUM Nicoll.
Peracreadium commune (Olsson).
Nicoll, 1910, pp. 328-9.
Only three specimens of this species were met with in Labrus berggylta
and Crenilabrus melops. They agree with my previous description, except
476 WILLIAM NICOLL.
that the ventral sucker is somewhat larger and more globular than in the
Clyde specimens. It is thus not a feature to distinguish this species from
P. genu.
Peracreadium genu (Itud.).
Nicoll, 1910, pp. 326-8.
This was obtained twice from the intestine of Labrus berggylta, but
never from any of the other Labridae (over 30 were examined). A
single immature specimen, however, occurred in the intestine of a shanny
(Blennius pholis). It was only -4 mm. long. The testes were oblique,
and the ovary on the right-side of the anterior testis. The cirrus-pouch
reached almost to the ovary. The yolk glands were not visible, and there
were no ova. It seemed impossible to determine whether this specimen
should be regarded as P. genu or P. commune, but in any case it must
be regarded as an adventitious parasite of the shanny.
Genus CAINOCREADIUM Nicoll.
Cainocreadium labracis (Dujardin).
Johnstone, 1908, pp. 44-53.
Half a dozen specimens of this species were taken from the intestine
of the only bass (Labrax lupus) examined.
Genus HELICOMETRA Odhner.
Helicometra pulchella (Rud.).
This was by far the commonest member of the Allocreadiidae met with.
As a parasite of littoral fishes it largely replaces Podocotyle atomon, which
is predominant on the east coast. At Plymouth it was met with in
twelve different hosts: Serranus cabrilla, Trigla pini, Gobius paganellus,
Blennius pholis, Blennius gattorugine, Lepadogaster gouani, Labrus miatus,
Labrus berggylta, Ctenolabrus rupestris, Zeugopterus punctatus, Anguilla
vulgarus and Conger conger. Ninety specimens of these fishes were ex-
amined, and the parasite was met with thirty-three times (i.e. 3 in 8). Its
chief hosts are the goby and the blennies. In these it occurred three
times in five.
A fairly full description, partly based on the material collected at
Plymouth, has already been given (Nicoll, 1910, pp. 335-40). The dis-
tribution of this species is rather noteworthy. It has been recorded from
the Mediterranean, from the English Channel and from the v est coast
of Scotland. It has never been recorded from the North Sea.
H. pulchella (Rud.) of Odhner (1902) from Northern fishes, is probably
a distinct species.
THE TREMATODE PARASITES OF FISHES. 477
Sub-Family STEPHANOCHASMINAE.
Genus STEPHANOCHASMUS Looss.
Stephanochasmus caducus Looss var. /wsct.
Numerous young specimens of a parasite which I can only with some
doubt identify as this species were taken on two occasions from the
duodenum and pylorie caeca of Gadus luscus. A single immature speci-
men was also found in the caeca of Gadus minutus.
They measure 1-5-3 mm. in length, and most of those over 2 mm.
contained ova. The cephalic spines are arranged in two rows of 25 each,
and those of the anterior row are shorter than those of the posterior row,
‘019 mm. and -021 mm. respectively. In a3 mm. species the oral sucker
has a diameter of -12 mm. and the ventral -14mm. The latter is situated
-63 mm. from the anterior end. The prepharynx is -21 mm. long, and
the pharynx measures -1 x -08 mm.
The cirrus-pouch extends -49 mm. behind the ventral sucker. The
vagina joins it behind the sucker, and the genital sinus is -2 mm. long.
The ovary, testes and yolk glands are situated as described by Looss, but
the yolk glands extend forward a short distance in front of the end of the
citrus-pouch. The few ova measure -066 x -036 mm.
The chief respects in which these specimens differ from Looss’s de-
scription (1901, p. 603) are the number and size of the cephalic spines,
the position of the ventral sucker, the inequality of the suckers and the
greater extent of the yolk glands. It seems possible to ascribe the first
two of these to difference in age and size of the specimens (Looss’s de-
scription was from specimens over 4 mm. long). The other two features,
together with the difference in number of the cephalic spines, do not
seem of sufficient importance to warrant establishing a new species, but
it seems advisable to regard this form as a distinct variety.
It is interesting to note that the specimen obtained by Miss Lebour
(1908, p. 36) from the whiting (Gadus merlanqus) does not entirely agree
with Looss’s description of S. caducus. The suckers are nearly twice as
great as those of Looss’s form. The yolk glands are more extensive and
the eggs are larger. It is possible that this may represent a third variety
of the same species.
Stephanochasmus cesticillus (Molin).
Looss, 1901, pp. 598-9.
Four specimens of this parasite were collected from the stomach and
intestine of Zeus faber. This is the first and only time this parasite has
478 WILLIAM NICOLL.
been recorded from British waters, and it is the only occasion on which
it has been met with in this host.
Sub-Family LepocrEADIrINak.
Genus LEPIDAPEDON Stafford.
Lepidapedon rachion (Cobbold).
Odhner, 1905, pp. 332-7 (Lepodora rachiaea).
Lebour, 1908, pp. 29-30.
This was found frequently in the intestine of the pollack (Gadus
pollachius) once in considerable numbers. It was not met with in any
of the other Gadoids, of which nearly 40 were examined.
Lepidauchen stenostoma Nicoll.
Nicoll, 1913a, pp. 240-1.
Two specimens were obtained from the intestine of Labrus berggylta.
This species has already been fully described. |
Genus PHARYNGORA Lebout.
Pharyngora bacillaris (Molin).
Nicoll, 1910, pp. 341-7.
This parasite was met with very frequently in the intestine of Scomber
scombrus, Gadus merlangus, Capros aper and Cyclopterus lumpus. Only
one specimen of the last-mentioned fish was examined (22nd April, 1910),
and it contained several thousand immature specimens ranging in length
from -6 mm. to 18mm. I have previously recorded the occurrence of
this parasite in the lumpsucker caught in St. Andrews Bay (1909, p. 22,
Distomum sp.). In that case, too, the parasites were all immature,
though very much fewer in number. In Capros aper, also, although I
have found the parasite in moderate numbers on four occasions, they
have always been immature. Only in the mackerel and whiting have
fully mature specimens been obtained. The mackerel is undoubtedly
the commonest host of this parasite.
Family FELLODISTOMIDAE.
Sub-Family FELLODISTOMINAE.
Genus STERINGOTREMA Odhner.
Steringotrema cluthense (Nicoll).
Nicoll, 1909, pp. 472-5.
This species was the commonest member of the family Fellodistomidae
THE TREMATODE PARASITES OF FISHES. 479
found on the south coast, and indeed the only one met with in Pleuronectid
fishes. It was found in five out of thirteen specimens of Pleuronectes
limanda and P. microcephalus. It has already been recorded in the
Fic. 2.—Steringotrema pagelli. Ventral view x33. C.B. Cirrus-pouch; K.St. Ovary ;
P.G, Genital aperture. Jf. Rhodes del.
latter host from the Firth of Clyde, but it is worthy of note that it has
not been met with in the North Sea, although over 100 specimens
of these two hosts have been examined. It has already been fully
described.
480 WILLIAM NICOLL.
Steringotrema divergens (Rud.).
Odhner, 1911, p. 103.
This species was met with in fairly large numbers on two occasions
(15th and 24th June, 1910) in Blennius ocellaris. It has hitherto
only been recorded from the Mediterranean Sea and only in this
host.
Compared with Odhner’s description the ventral sucker in my speci-
mens is less anisodiametric. The ratio of the two diameters being 6:7
instead of 6: 8. The cesophagus is more contracted and wider, while the
intestinal diverticula do not reach the middle of the testes. The ovary
shows slight indentation, giving it a somewhat indistinctly trilobate
appearance.
Steringotrema pagelli (van Beneden) (Fig. 2).
Odhner, 1911, p. 102.
A few specimens of this species were collected from the intestine of a
sea-bream (Sparus centrodontus) obtained from Billingsgate Market,
London (19th June, 1912). It was not possible to ascertain whether the
fish was captured in the North Sea or in the English Channel. When
collected the specimens were already dead and somewhat macerated.
They were of a dull grey colour and remarkable for their great
thickness and the unusual size and prominence of the ventral
sucker.
The specimens measure 3-6—4-1 mm. in length with a greatest breadth
of 1-6-1-8 mm. Both ends of the body are pointed. The oral sucker,
which in every case is elongated, measures about -48x-39 mm. in a
specimen 3-8 mm. long. The ventral sucker, circular or transversely
oval in outline, measures 1-05 1-16 mm., so that the ratio is not quite
as much as 3:1. The distance of the centre of the ventral sucker from
the anterior end is about 1-8 mm.; it thus lies a little in front of the
middle of the body.
The pharynx has a diameter of -17 mm., and the cesophagus is somewhat
longer. The intestinal diverticula diverge widely. Their ends are
obscured by the great mass of ova.
The ovary and testes are also almost completely hidden by the uterus.
The cirrus-pouch is a long bulbous structure lying immediately in front
of the ventral sucker, which it touches. The aperture is on the level of
the intestinal bifurcation and about midway between it and the left
margin of the body. The vesicula seminalis is of comparatively large
size.
THE TREMATODE PARASITES OF FISHES. 481
The yolk glands are situated at the sides of the ventral sucker and
extend a short distance both in front of and behind it. Their extent is
more limited than in S. cluthense. The uterus is very firmly packed and
fills almost the whole of the post-acetabular region. The ova have thick
brown shells and measure -057—-063 x -033--037 mm. Their measure-
ments are considerably larger than those found by Odhner for the same
species.
Genus BACCIGER n.g.
Bacciger bacciger (Rud., Stoss., 1889) (Fig. 3).
On two occasions a single specimen of a small distome was found
in the stomach of Atherina presbyter. The fish were received in London
Fic. 3.—Bacciger bacciger. Ventral view x100. C.B. Cirrus-pouch; K.St. Ovary ;
T. Testes. G. Roberts del.
from Plymouth, and on that account the viscera were somewhat decom-
posed and the parasites badly preserved. From what could be made out
of their anatomy, however, they appear to be either identical with or
very closely related to Distomum baccigerum (Rud.) Stossich from
Atherina hepsetus.
NEW SERIES.—VOL. X. NO. 3. OCTOBER, 1914. 2H
482 WILLIAM NICOLL.
The body is flat and of oval outline. The cuticule is unarmed. The
length of the body (slightly pressed) is -95 mm., and the maximum
breadth in the middle, -52 mm. The sub-terminal oral sucker has a
diameter of -105 mm., and the ventral sucker, situated a little in front
of the middle of the body, measures -15 mm. There is a small pharynx,
contiguous in the oral sucker. The cesophagus is two or three times as
long as the pharynx, the intestinal bifurcation taking place about midway
between the pharynx and the genital aperture. The intestinal diverticula
are very narrow, they extend into the posterior part of the body, but
their termination is obscured by the uterus.
The genital aperture is median, and lies about -15 mm. in front of the
ventral sucker. There is a small, stout cirrus-pouch lying entirely in
front of but almost touching the ventral sucker. At its posterior end it
contains a small, simple vesicula seminalis. This is followed by a short
inflated pars prostatica. The ductus ejaculatorius is short and wide and
its walls are thrown into irregular folds, resembling the condition in
Steringophorus. The testes are symmetrically situated, one on each side
of the body, immediately behind the ventral sucker. They are globular
or elongated oval bodies a little larger than the ventral sucker.
The ovary is situated between the testes, directly behind the ventral
sucker. It is globular and somewhat smaller than the testes. The yolk
glands occupy the sides of the body in front of the ventral sucker, and
they extend from the middle of the sucker to the level of the cesophacus.
The yolk ducts run backwards and unite behind the ovary. The uterus is
confined entirely behind the testes. It forms a large number of narrow
convolutions chiefly in a longitudinal direction. The initial convolutions
are on the left side of the body, where the eggs are almost colourless.
Towards the other side the colour gradually deepens. The vagina is
apparently simple. The numerous eggs measure -020—-024 x -014—
O17 mm.
In Stossich’s figure the intestinal bifurcation is much nearer the ventral
sucker than is the case in my specimens; the testes are much larger
and the cirrus-pouch is not shown. The genital aperture also is described
as being immediately behind the pharynx. How far these discrepancies
are due to errors of observation it is impossible to say, as I have had no
opportunity of examining Stossich’s original material.
This species undoubtedly represents the type of a distinct genus of
the family FELLODISTOMIDAE and the sub-family FELLODISTOMINAR.
Its general build rather suggests an affinity with the Monorchidae, but
the structure of the cirrus-pouch and vagina excludes it from that family.
THE TREMATODE PARASITES OF FISHES. 483
Sub-Family HaAPLOCLADINAE.
Genus TERGESTIA Stossich.
Tergestia laticollis (Molin).
Odhner, 1911, p. 111-13; Nicoll, 1913b, pp. 192-3.
This species was found frequently in the intestine of the horse-mackerel
(Trachurus trachurus). It occurs occasionally in fairly large numbers,
though as a rule only a few specimens are present in one host. It appears
to be an exclusive parasite of this host.
Family ZOOGONIDAE.
Sub-Family ZooGONINAE.
Genus ZOOGONOIDES Odhner.
Zoogonoides viviparus (Olsson).
Odhner, 1902a, p. 62; Nicoll, 1907, p. 83.
This very common parasite has already been recorded*from eight
species of British fishes. An additional five have here to be noted,
namely, Zeus faber, Blennius gattorugine, B. ocellaris, Solea vulgaris,
S. variegata. It was also found in Callionymus lyra, Pleuronectes limanda,
P. microcephalus and P. platessa.. The chief hosts of this parasite are
undoubtedly Callionymus lyra, Pleuronectes spp. and Solea spp. It 1s
rather curious that it has never once been recorded from Gadoid fishes
or from the Labridae. It is worth remarking that the specimens I
obtained from the cat-fish (Anarrhichas lupus) at St. Andrews belong to
this species and not to the more recently discovered Z. subaequiporus
Odhner, from the same host.
Genus ZOONOGENUS Nicoll.
Zoonogenus vividus Nicoll.
Nicoll, 1912, pp. 200-2,
A species which I have already described was met with frequently in
the intestine of Sparus centrodontus. As I have previously remarked, it
is an extremely delicate species and exceedingly difficult to preserve in a
satisfactory state. An additional six bream obtained from Billingsgate
Market were examined in June, 1912, but they were not infected with the
parasite.
484 WILLIAM NICOLL.
Family MONORCHIDAE.
Sub-Family MonorcuInae.
Genus MONORCHIS Monticelli.
Monorchis monorchis (Stossich).
Looss, 1902b, pp. 117-18.
A couple of specimens of this parasite were found in the intestine of
Blennius gattorugine.
Family HAPLOPORIDAE.
Genus SACCOCOELIUM Looss.
Saccocoelium obesum Looss.
Looss, 1902a, pp. 140-1.
A few specimens of this parasite were found in the intestine of a grey
mullet (Mugil chelo).
Genus HAPLOPORUS Looss.
Haploporus benedeni (Stossich).
Looss, 1902a, pp. 136-8.
A few specimens were obtained from the intestine of a grey mullet
(Mugil chelo) along with specimens of Saccocoelium obesum.
Family AZYGIIDAE.
Genus PTYCHOGONIMUS Lithe.
Ptychogonimus megastomus (Rud.).
Jacoby, 1899, pp. 16-24 ; Jagerskidld, 1900, pp. 68-74.
This"parasite was obtained from the stomach of four out of six speci-
mens of Mustelus vulgaris. It usually occurred in moderate numbers.
Family HEMIURIDAE.
Sub-Family Hemiurinae.
Genus HEMIURUS (Rud.).
Hemiurus communis Odhner.
Odhner, 1905, p. 351; Lebour, 1908, p. 46.
This exceedingly common and widespread fish parasite was met
with in”sixteen different species of fish, namely, Sparus centrodontus,
Capros aper, Lophius piscatorius, Cottus bubalis, Trigla pint, T. gurnardus,
Gobius paganellus, Lepadogaster gouanti, Gadus luscus, G. merlangus,
G. minutus, G. pollachius, Ammodytes lanceolatus, Molva molva, Zeugop-
THE TREMATODE PARASITES OF FISHES. 485
terus punctatus and Nerophis aequoreus. The species is now known to
occur in thirty species of British marine fishes, and it is, with the
exception of Derogenes varicus, the most widely distributed of all British
fish parasites. In the above list the bream (Sparus centrodontus) from
which the parasites were obtained were bought in the London market, so
that their actual origin is unknown. None of the bream examined at
Plymouth harboured the parasite.
Although so widely distributed, the parasite shows a distinct preference
for Gadoid fishes, of which eleven species have been found to harbour it.
I have myself examined over 120 Gadoids and found the parasite in
34% of them. Amongst the total number of other fishes which I have
examined it has been present in less than 59%. Next to the Gadoids,
Cottus bubalis and Hippoglossus vulgaris are probably the most frequent
hosts.
Hemiurus ocreatus (Rud.).
=H. LUHEI Odhner.
Odhner, 1905, p. 352 ; Nicoll, 1909, pp. 21-2.
By far the commonest host of this parasite was found to be the pilchard
(Clupea pilchardus). It was also met with on one occasion in each of the
following hosts: Trachurus trachurus, Capros aper, Scomber scombrus,
Gadus merlangus, and G. pollachius.
Sub-Family (DINuURINAE).
Genus LECITHOCLADIUM Liihe.
Lecithocladium excisum (L[ud.).
Looss, 1907, pp. 131-2.
This species was found only in the stomach of the mackerel (Scomber
scombrus). It occurred in three out of eight specimens examined.
Sub-Family STERRHURINAE.
Genus LECITHOCHIRIUM Liihe.
Lecithochirium rufoviride (Rud.).
Looss, 1907, p. 147.
This was found in the stomach of the common eel (Angqualla vulgaris),
the conger (Conger conger) and the angler (Lophius piscatorius). It is an
extremely common parasite of the first two fishes, but has not previously
been recorded from Lophius. Looss regards the conger as the only
authentic host of the parasite, but there is no doubt that the single
486 WILLIAM NICOLL.
specimen I have obtained from Lophius really belongs to this species. It
is about 5 mm. in length and has suckers measuring respectively -65 mm.
and -78 mm. in diameter.
The encysted stage of this parasite was met with frequently in the
shanny (Blennius pholis). It occurred in fairly large opaque brown cysts
measuring ‘7-1-4 mm. in diameter. They were attached to various
abdominal viscera, but chiefly the intestine and the liver. They were
commonest in the intestinal wall, either loosely attached or firmly
embedded, and in more than one case free larvee were found actually in
the intestine. The larve when freed from the cyst were about 2 mm. in
length (ecsoma retracted), and they had suckers measuring -28 mm. and
‘4 mm. respectively in diameter. The genital organs were well developed
and fairly numerous eggs were present in many. These measured
015 x -009 mm.
The occurrence of the larve of Lecithochirium gravidum encysted in
pipe-fishes has already been recorded by Looss (1907, p. 148).
Genus SYNAPTOBOTHRIUM von Linstow.
Synaptobothrium caudiporum (Rud.).
Looss, 1907, pp. 150-2.
This parasite has not hitherto been recorded from British waters. It
occurred in the stomach of three out of five specimens of Trigla hirundo
and once in Zeus faber and Lophius piscatorius. The specimens are
considerably larger than those examined by Looss, reaching a length of
4 mm. (unpressed specimens) or 5 mm. (pressed specimens). The vesicula
seminalis is confined entirely in front of the ventral sucker, while the
metraterm may reach the centre of the sucker. The eggs have the
characteristic shape described by Looss.
Encysted larve of this specimen were found along with those of
Lecithochirium rufoviride in the liver and intestinal wall of a small
specimen of Labrus berggylta, and two cysts were found in the intestinal
wall of Crenilabrus melops.
Sub-Family LEcIrHASTERINAE.
Genus LECITHASTER Liihe.
Lecithaster gibbosus (Rud.).
Looss, 1907, p. 164; Odhner, 1905, pp. 356-8 ; Nicoll, 1909, pp. 18-20.
This parasite occurred in seven different hosts, namely, Serranus
cabrilla, Trachurus trachurus, Zeus faber, Trachinus vipera, Trigla pum,
THE TREMATODE PARASITES OF FISHES, 487
Gadus merlangus, and Zeugopterus norvegicus. Though fairly widespread,
it is by no means a common parasite, and its numbers in any particular
host rarely exceed two or three.
Sub-Family SyNCOELIINAE,
Genus DEROGENES Lie.
Derogenes varicus (O. F. Miiller).
Odhner, 1905, pp. 360-4 ; Johnstone, 1907, pp. 188-92 ;
Lebour, 1908, pp. 45-6.
By far the commonest of marine fish parasites, this species was found
in the stomach of twenty-eight different hosts, namely, Mullus barbatus,
Sparus centrodontus, Trachurus trachurus, Capros aper, Zeus faber,
Trachinus vipera, T. draco, Lophius piscatorius, Cottus bubalis, Agonus
cataphractus, Callionymus lyra, Trigla pini, T. gurnardus, T. hirundo,
Cyclopterus lumpus, Blennius ocellaris, Gadus luscus, G. minutus, G.
merlangus, G. pollachius, Molva molva, Onos tricirratus, Bothus maximus,
Pleuronectes flesus, P. limanda, Solea vulgaris, Salmo trutta, and Conger
conger.
Genus HEMIPERA Nicoll.
Hemipera ovocaudata Nicoll.
Nicoll, 1913a, pp. 242-3.
This species was found a few times in the stomach of Lepadogaster
gouant.
Genus DEROGENOIDES Nicoll.
Derogenoides ovacutus Nicoll.
Nicoll, 1913a, pp. 243-6.
This parasite was met with only once in the stomach of a weever,
Trachinus draco.
Family BUNODERIDAE.
Genus BUNODERA Railliet.
Bunodera nodulosa (Zeder).
Looss, 1894, pp. 33-41.
A few specimens of this species were obtained from the intestine of a
trout (Salmo trutta) from the River Yealm.
488 WILLIAM. NICOLL.
Family ACANTHOCHASMIDAE.
Genus ACANTHOCHASMUS Looss.
Acanthochasmus imbutiformis (Molin).
Looss, 1901, pp. 632-3 ; Johnstone, 1906, pp. 177-9.
About thirty specimens of this parasite were found in the intestine of
Labrax lupus.
What appears to be the larval stage of this parasite was found encysted
in the gills of the pipe-fish, Szphonostoma typhle. A single cyst containing
a living larva was also found on one occasion amongst the stomach
contents of a whiting (Gadus merlanqus).
The cysts in the gills of Scphonostoma are oval and measure -3—-65 mm.
in length. The oral sucker is slightly larger than the ventral, and is
surrounded by eighteen cephalic spines. The cyst in the whiting had a
diameter of -38 mm. and the cercaria a length of 1-5 mm. The oral sucker
measured -15 mm. and the ventral-17 mm. The cephalic spines numbered
aighteen and measured -056 mm. in length.
GASTEROSTOMATA.
Of this sub-order eight different species were collected, only one of
which appears to be hitherto undescribed. A remarkable feature of this
group is the great variation in the anatomical topography which may
occur, even within specific limits. This variation affects chiefly the
position of the genital glands and of the mouth. The size of the excretory
vesicle also varies considerably. On the other hand, the position of the
yolk glands and the size of the cirrus-pouch are fairly constant.
The variation is particularly well illustrated in the case of Proso-
rhynchus crucibulum (Rud.), in which as regards the position of the
genital clands no two descriptions have yet agreed. It has been pointed
- out (Nicoll, 1910) that these discrepancies are due to the extreme varia-
tion in the position of the genital glands in this species. A similar, but
less extensive, variation is found in Prosorhynchus aculeatus Odhner.
Within generic limits a still wider variation may be observed. In
illustration it is sufficient to compare the condition in Prosorhynchus
squamatus Odhner with that in P. aculeatus. In the former the ovary and
testes lie almost directly one behind the other, along the right margin of
the middle part of the body. In P. aculeatus, on the other hand, they are
disposed in a triangle in the posterior part of the body, the ovary being
in front and the testes lying one on each side of the body.
THE TREMATODE PARASITES OF FISHES. 489
In the prosostomate distomes we are accustomed to regard the relative
position of the genital glands as constant within narrow limits for the
same species, and any such difference as exists between P. squamatus and
P. aculeatus would be sufficient to warrant generic separation. In the
-Gasterostomata, however, it is evident that one cannot regard this feature
as a satisfactory basis of classification, and recourse must be had to others
of a more constant nature. Odhner has already (1905) denoted the
chief of these, namely, the structure of the copulatory organs, the struc-
ture of the head and the disposition of the yolk glands.
Apart from the situation of the genital glands and the configuration
of the uterus, the species included in the genus Prosorhynchus appear to
form a homogeneous group. The same, however, cannot be said with
regard to the remaining species of Gasterostomes, cluded by Odhner
under the genus Gasterostomum (=Bucephalus).
They all agree in having the yolk glands arranged in two distinct
eroups, which are usually marginal in position, and, so far as is known,
the structure of the copulatory organs does not vary very much from the
type found in Bucephalus polymorphus (=Gasterostomum fimbriatum).
It is in the structure of the anterior end that we meet with the most
pronounced features of difference. Three main types may be recognised.
(1) The anterior end may be provided with a simple sucker as in Gastero-
stomum gracilescens and G. tergestinum. This sucker closely resembles
the ventral sucker of the prosostomate distomes, and is regarded by
Odhner as the primitive type of head structure in the Gasterostomes.
(2) From the sucker muscular prolongations may grow out in the form of
tentacles or fimbriae as in G. fimbriatum and G. minimum Stossich.
(5) The sucker may degenerate in musculature, become very shallow and
be surmounted by a contractile fan-shaped hood as in G. triglae and G.
viperae. It is apparent that some generic separation of these three
groups is desirable, and it is only on the structure of the anterior end that
this is practicable. Hach of these three groups has already, in earlier
literature, been regarded as of generic or at least subgeneric importance.
The synonymy is shghtly complicated.
The monotypical genus Gasterostomum was founded on G. fimbriatum,
and as this has been shown to be the adult of the earlier known Bucephalus
polymorphus the name Gasterostomum fimbriatum must be regarded as
nomen nudum and the genus Gasterostomum as a synonym of Bucephalus.
In 1855 Diesing erected the sub-genus Bucephalopsis for the larval
form B. haimeanus, and this has been shown to be the larva of Gastero-
stomum gracilescens (Rud.). This species is undoubtedly the type of a
490 WILLIAM NICOLL.
distinct genus, and on that account I propose to raise the sub-genus
Bucephalopsis to generic rank with B. gracilescens (Rud., 1819) as type.
A complication enters here, however, for in 1858 Diesing erected the
genus Rhipidocotyle for the reception of the two species G. gracilescens
and G. minimum Wagener (nec. Stossich) without designating the type.
Stiles & Hassall (1908) have tentatively taken G. gracilescens as the type
of this genus, but, as I shall show, G. minimum Wagener is undoubtedly
the real type of this genus.
I am, unfortunately, not personally familar with Wagener’s original
specimens, nor have I had an opportunity of examining any Gasterostomes
from the type host, T'rigla nucrolepidota, but a careful study of Wagener’s
original figure (1852) has suggested to me that G. minimum Wagener is
identified with G. triglae van Beneden, 1870, and with the form which I
have described under that name (1909). The most characteristic feature
of this species is the highly contractile fan-shaped structure which
surmounts the anterior sucker. To both Wagener and van Beneden this
structure must have appeared in a very contracted condition and so have
escaped observation. Diesing, however, must have been familiar with
it and have been influenced by it in his choice of a generic name, hence
the highly descriptive combination Rhipidocotyle (pimis, piwidos=a fan,
koTvAy=a cup). No more appropriate term could have been invented.
At the same time it is remarkable that Diesing should have included in
the same genus G. gracilescens, which possesses no such fan-shaped
structure.
There is nothing in the remaining anatomy of either of these species
which to my mind bears the slightest resemblance to a fan, and on that
account I am convinced that it was the fan-shaped cephalic hood which
Diesing regarded as the distinctive feature of this genus. It will thus be
necessary to revive the old generic term which Odhner (1905, p. 296,
note 3) somewhat cavalierly consigned to the “‘ lumber room of useless
names.”
As Gasterostomum has become a nomen nudum the family name
Gasterostomidae must be replaced by Bucephalidae, and this family will
now include the genera Bucephalus Baer, 1827, Bucephalopsis (Diesing,
1855), Rhipidocotyle Diesing, 1858, and Prosorhynchus Odhner, 1905.
As Odhner has already suggested, a further separation of these genera
appears advisable. I propose to separate them into two sub-families,
Bucephalinae, n. subfam. and Prosorhynchinae, n. subfam.
The definitions of these sub-families are identical with the definitions
given by Odhner (1905, pp. 296-7) for the genera Gasterostomum and
THE TREMATODE PARASITES OF FISHES. 491
Prosorhynchus respectively. Bucephalinae includes the genera Buce-
phalus, as type, Bucephalopsis and Rhipidocotyle.
The definition of these three genera may be summed up briefly as
follows :—
Bucephalus Baer, 1827.
Bucephalinae in which the anterior end is provided with a muscular
sucker around which are a number of muscular retractile tentacles or
fimbriae. Type: B. polymorphus Baer, 1827 (=Gasterostomum fimbria-
tum v. Siebold, 1848) B. minimus (Stossich) (Gasterostomum minimum
Stossich, 1887, nec. Wagener, 1852) may also be included in this genus.
Gasterostomum gorgon Linton, 1905, may be provisionally included
here, but will probably require to be regarded as the type of a distinct
genus. The “ Gasterostomum sp.” depicted by Linton (1910, Fig. 225)
from Sphyraena barracuda may possibly belong to this genus.
Bucephalopsis Diesing, 1855.
Bucephalinae in which the anterior end is provided with a simple
globular muscular sucker. Type: B. gracilescens (Rud., 1819). G.
tergestinum Stossich, 1883, should be included here, and probably a
number of American forms.
Rhipidocotyle Diesing, 1858.
Bucephalinae in which the anterior end is provided with a feebly
developed, shallow sucker surmounted by a fan-shaped hood. When this
is contracted the anterior end appears square. Type: R. minima
(Wagener, 1852), Nicoll, 1914 (=Gasterostomum triglae van Ben., 1870,
Nicoll, 1909), includes also R. viperae (van Ben., 1870), Nicoll, 1914, and
probably a number of species from American fishes (Linton, 1910,
Figs. 217, 222, 223).
Family BUCEPHALIDAE.
Sub-Family BucEPHALINAE.
Genus BUCEPHALOPSIS (Diesing).
Bucephalopsis gracilescens (Rud.).
Lebour, 1908, pp. 18-21.
This common parasite of Lophius piscatorius was found in four out of
five specimens of that fish. It occurred in the intestine and pyloric
caeca, usually in large numbers.
492 WILLIAM NICOLL.
Genus BUCEPHALUS Baer.
Bucephalus minimus (Stossich).
=Gasterostomum minimum Stossich, 1887, p. 96.
About two dozen specimens of a small Gasterostome were found in the
intestine of Labrax lupus. They correspond in most respects with
Stossich’s description of Gasterostomum minimum from the same host,
but the position of the testes and the extent of the uterus are different.
It is a small plump form reaching a length of a little over 1 mm. The
outline is oval and the maximum breadth is about half the length. The
anterior sucker is terminal and is surrounded by a circle of six highly
contractile tentacles. When extended these tentacles may be long and
almost filiform. When completely retracted they are almost impossible
to discern. In a semi-contracted state they appear as small, fleshy,
knob-like protuberances.
The ovary lies on the right side of the pharynx, which is situated
about the middle of the body. The testes lie directly behind the pharynx.
They are oblique and overlap each other considerably. The uterus fills
up a large part of the body, extending forward as far as the level of the
anterior sucker. The ova measure :022—-024 x -013--015 mm.
Genus RHIPIDOCOTYLE Diesing.
Rhipidocotyle minima (Wagener).
=CGasterotomum triglae (van Ben.), Nicoll.
This species was met with in the intestine of the gurnards, T’rigla pina,
T. gurnardus, and T. hirundo. In the last-named it occurred also in the
pyloric caeca. The parasite was not found in the half-dozen specimens
ot Trigla lyra which were examined.
The only note which may be added to my previous description (Nicoll,
1909, pp. 23-4) is that in this species the excretory vesicle is of great length
and extends a considerable distance in front of the ventral sucker. It
even reaches further forward than the fundus of the stomach.
Several specimens of what appeared to be this species were met with
in the intestine of Tvrachinus vipera. They agree in every particular
except that the pharynx is situated further back. It is constantly
behind the middle of the body, and may even be found as far back as the
anterior end of the cirrus-pouch. Its relation to the other organs is
consequently very variable. Sometimes it is on the level of the anterior
testis. The only other noticeable feature is that the anterior sucker and
the pharynx are less unequal in diameter than is the case in typical
THE TREMATODE PARASITES OF FISHES. 495
examples of G. triglae. In consequence of the great variation which
undoubtedly occurs it is not thought advisable to regard this as a distinct
species.
Rhipidocotyle viperae (van Ben.) (Fig. 4).
I am identifying as this species a few Gasterostomes which were
obtained from the intestine of Trachinus draco. It is a form which
resembles G. triglae in general appearance, but which differs from it in
ho
e »
5 ee ane
Kst-# S
as 4
Fic. 4.—Rhipidocotyle viperae. Ventral view x85. C.B. Cirrus-pouch; K.St. Ovary ;
Ph. Pharynx; T. Testes. G. Roberts del,
having the genital glands arranged differently and in having a long and
slender cirrus-pouch which extends forward to near the middle of the
body.
The length of mature specimens is -7-1-2 mm., and the maximum
breadth in the middle of the body is about -4 mm. The anterior end
is square-cut and the posterior end pointed. The whole surface of the
body is beset with minute spines.
At the anterior end there is a shallow sucker measuring, in the largest
specimen, -13 mm. in diameter. Its musculature is very feebly developed.
Surmounting the sucker is a five-rayed fan-shaped structure, closely
494 WILLIAM NICOLL.
resembling the corresponding structure in R. minimum. This is not
represented in van Beneden’s figure.
The pharynx (ventral sucker) is situated -8 mm. from the anterior
end of the body. Its diameter is about -055 mm. The short intestinal
sac is obscured by the uterus.
The genital glands lie close together on the right side a short distance
in front of the mouth. The ovary is about -6 mm. from the anterior end
of the body and lies close up against the side. It is globular and has a
‘diameter of -1 mm. The testes are contiguous to it and to each other,
the first testis lying alongside and a little in front of the ovary, the second
testis lying directly behind the ovary and first testis. Both testes are
globular and somewhat larger than the ovary, having a diameter of
-12mm. In van Beneden’s figure the testes are separated by the pharynx,
and what might be regarded as the ovary lies in front. It is possible,
however, that that problematic structure really EERE the intestinal
sac, in which case the ovary is not shown.
The yolk glands extend along the margins of the body from the level
of the ovary to a point about -25 mm. from the anterior end. The uterus
fills up the space between the yolk glands and passes backwards between
the testes and the pharynx. The ova measure -036—-037 x -018—-021 mm.
The cirrus-pouch is a long slender structure which extends forwards
to a short distance in front of the mouth. There is a fairly large simple
vesicula seminalis, a long pars prostatica and a short ductus.
Sub-Family PROSORHYNCHINAE.
Genus PROSORHYNCHUS Odhner.
Prosorhynchus squamatus Odhner.
Odhner, 1905, pp. 297-304 ; Lebour, 1908, pp. 21-3.
This was found on two occasions in the duodenum of Cottus bubalis,
the first time in large numbers, the second time as a single specimen.
Prosorhynchus aculeatus Odhuer.
Nicoll, 1910, pp. 350-2.
This common parasite of the conger was found in three out of four
specimens of the fish.
Prosorhynchus crucibulum (Molin).
Nicoll, 1910, pp. 352-4.
This was found in association with P. aculeatus and quite as frequently.
THE TREMATODE PARASITES OF FISHES.
495
Prosorhynchus triglae sp. ing. (Fig. 5).
Single specimens of this species were found on two occasions, once in
the intestine and once in the stomach of Trigla gurnardus. Both speci-
mens were quite immature, so that it is impossible to give a complete
description of the species, which appears to be hitherto unrecorded.
It measures 2-2—2-4 mm. in length and -75 mm. in maximum breadth.
At the anterior end there is a wedge-shaped rostellum resembling that in
& y7 7
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. % . -
cite 3
eae La sho ena
: IIPS S Sp og APP OP
ei
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Fic. 5.—Prosorhynchus triglae. Ventral view x 40.
vesicle; K.St. Ovary ; Ph. Pharynx; T. Testes.
P. crucibulum (diameter -3 mm.).
C.B. Cirrus-pouch ; Ex. Excretory
G. Roberts del.
The small ventral sucker (pharynx)
is situated nearly in the middle of the body (diameter -1 mm.).
The intestinal sac extends forwards and is not of very large size.
The excretory vesicle extends about one-half or two-thirds the distance
between the posterior end of the body and the pharynx.
The cirrus-pouch is about half the length of the excretory vesicle. The
the left in the other.
testes are fairly large, close together and nearly tandem. The posterior
(left) testis is contiguous with the cirrus-pouch in one and displaced to
496 WILLIAM NICOLL.
The small ovary lies immediately in front of the anterior testis on the
right side. The yolk glands were not distinct.
AS
ih
Nei. fey
MY ane
A
‘
.
s
OZ
ra) AO ag \ o*o =) a0g Detend.
O ; Qo a_g
ey (@) 2) O° Flows
ee 6 a @ ee:
en
[e 3
Fic. 12.—Anthopleura alfordi. Vertical section
through the peristome wall, showing a fold,
and the origin of a mesentery.
In a longitudinal section through a tentacle the ectodermal muscle can
be seen as a thin plate of tissue arising from the more deeply stained
mesogloea. Lobes and stunted irregular processes penetrate the endoderm.
Full-sized‘nematocysts are situated near the outer edge of the ectoderm,
COMPARATIVE ANATOMY OF SOME BRITISH ACTINIA. 543
while immature ones are embedded in the middle of the ectodermal
tissue and are deeply stained. The older ones are longer and more
transparent. The spiral thread could be faintly distinguished in one or
two cases ; it is very fine and has a large number of coils. The nemato-
cysts are more numerous at the tip, but they are well developed along the
stem.
A. alfordi and A. gelam are alike in the following respects : they have
more than six pairs of perfect mesenteries ; they possess a well-circum-
scribed endodermal muscle. I therefore suggest the following as an
amended definition of Anthopleura : Cribrinidee with the upper portion
of the column wall provided with longitudinal rows of verruce, the lower
portion being smooth. The margin forms a more or less distinct collar
and the tentacles are polycyclic and entacmeous. More than six pairs
of mesenteries of the first cycle are perfect.
Corynactis viridis (Allman, 1846).
Classification: The following is the classification adopted by Haddon :—
Tribe : Hexactinie (Hertwig, 1882).
Order : Stichodactyline (Andres).
Sub-order : Homodactyline (Duerden).
Family : Corallimorphide (Hertwig).
Genus : Corynactis (Allman).
Species : viridis.
Haddon gives the following definition of the Stichodactyline : “‘ Hex-
actinie in which more than one tentacle may communicate with a
mesenterial chamber. Usually a peripheral series of one or more cycles
can be distinguished from an inner accessory series, the members of which
are radially arranged or in groups, and are of different form. The sphincter
muscle may be endodermal or absent.’ Branched tentacles appear quite
often.
Duerden has divided the Stichodactyline into two sub-orders :—
(a) The Heterodactyline in which the tentacles are of two kinds,
usually marginal and accessory, and separated by a bare portion of the
disk, e.g. Actinotryx, Rhodactis, Heterodactyla.
(6) The Homodactyline in which the tentacles are of one kind, simple
or complex, and usually follow one another in continuous rows, e.g.
Richordea, Corynactis, Stoichactis.
Family : Corallimorphide. Stichodactyline with a marginal corona
of tentacles, and accessory tentacles, arranged in radial series each con-
544 OLWEN M. REES.
sisting of from one to many tentacles. The muscular system is weak
throughout the body.
Genus: Corynactis. Corallimorphide in which the body-wall is smooth.
The tentacles are all knobbed and are arranged in radial series so that
more than one communicates with each inter- or intra-mesenterial space.
Tentacles and mesenteries tetramerous. Gonidial groove present or
absent. Endodermal sphincter very weak. Mesenterial filaments devoid
of ciliated streak.
Mesogloea practically homogeneous.
Corynactis viridis (Allman, 1846).
The word Corynactis (Greek=club-stick) refers to the shape of the
tentacle.
The emerald-green ring round the capitulum was said to be character-
istic of C. viridis found in European seas; this green ring was also
found on C. carnea (Buenos Ayres) and on C. australis (Port Phillip,
Australia).
The specimens I examined were obtained from Plymouth, and were
collected on the Breakwater. Some were brightly coloured, green and
yellow, others were almost colourless. The following measurements were
taken from a preserved specimen from Plymouth :—
Diameter of pedal disk=5 mm.
2.
rs + column ~/=-2-5) mim.
- ,, Orel disk) —4 mm,
Length of column =): mm.
Be ,, wventacle —imm*;
The external appearance of C. viridis has been described by many of
the older writers. In 1884 Andres describes it in L’ Aitinie in page 266.
In the report on Actimiaria dredged by H.M.S. Challenger, 1873-76,
Hertwig gives the arrangement of the mesenteries. The first account
was written by Allman in the Annals and Magazine of Natural History
in 1846. Allman obtained his specimens near low-water mark in the
pools left by the retiring tide in Crook Haven, Co. Cork. One of his
specimens was a fairly large one measuring 5 inch across the tentacular
disk.
In Allman’s specimen the colour of the tentacular disk was bright
green, except for a circle of radiating brown striz which surrounded.
the mouth at a short distance from its margin. The stems of the tentacles
were of a sienna colour and their extremities were of a bright rose. He
found varieties which were not uncommon, in which the green colour
COMPARATIVE ANATOMY OF SOME BRITISH ACTINIA. 545
except in a narrow ring at the upper margin of the body was entirely
replaced by a light flesh colour. Andres’ specimen possessed a brilliant
metallic iridescence.
In all the paler varieties the animal becomes translucent when ex-
panded, so that the septa and vermiform filaments may be seen through
the body-wall. This is evidently an example of albinism. The animal
changes its form very often, at one time it will assume the appearance of
a slender cylindrical stem, fixed by one extremity and bearing on the
other extremity a flattened disk. Sometimes a contraction will take
place in the middle of the body so as to cause the animal to present some-
what the appearance of an hour-glass. In assuming its many different
forms the stomatodaeum is never everted.
Allman found two concentric rows of tentacles arising near the margin
of the disk, but the number and arrangement is variable. They are
tubular like the tentacles of other Actimize and communicate freely
with the interseptal spaces. They are imperforate at the apices, which
are very much swollen.
I have examined specimens of C. viridis chiefly with the aim of com-
paring it anatomically with the Australian specimens, which are the only
Corynactids well known in this respect.
Anatomy and Histology :—
The ectoderm of the column wall is fairly spongy in places, in other
places it is like that of C. myrcia, described by Duerden, and consists of
large unicellular gland cells mingled with narrow supporting cells. The
gland cells become swollen near the free surface, where in places they give
rise to a clear zone. The contents of these cells are usually clear, and then
they do not take stain easily but stand out as highly refractive bodies.
In other cases they become deeply stained because the contents are
granular.
The nuclei of the ectoderm cells are deeply stained, and as in C. hoplites
and C’. myrcia they are arranged in a zone a little within the middle of
the ectoderm layer.
The interior part of the layer forms a clear zone, this marks the posi-
tion of part of the nervous system. The ectodermal muscle can be dis-
tinguished at the base of the ectoderm. The body-wall of the pedal disk
is fully expanded, and therefore appears very narrow as compared with
that of the column. The ectoderm of the base appears to be one-fourth
of the thickness of that of the column wall. In this region the ectodermal
muscle is very strong and thick processes of mesogloea can be seen
546 OLWEN M. REES.
projecting into the ectoderm. A layer of foreign material is attached to
the outer region of the ectoderm. The mesogloea is a very thin layer,
being only one-quarter the thickness of the ectoderm. It becomes deeply
stained, is homogeneous, showing no fibrillar structure ; and is thicker
in places owing to the contraction of the body-wall. In structure it
appears to resemble C. hoplites and C. myrcia, but mm C. hoplites it is
about the same average thickness as the ectoderm. The mesogloea of
C. australis is also of considerable thickness.
The endoderm of the column is much narrower than the ectoderm.
In this C. viridis differs from C. myrcia, where endoderm and ectoderm
are of about the same thickness. In C. viridis the endoderm becomes
thicker near the base. It consists of a spongy mass, and is not so deeply
stained on the whole as the ectoderm. In some places there are large
oval gland cells which contain a granular substance, these seem to be
more numerous in the endoderm than in the ectoderm. The endodermal
muscle is very feebly developed, but appears stronger in the base.
There are no zooxanthellze present in this anemone, nor has their
presence been indicated in any of the other members of this genus.
The sphincter muscle (Fig. 13) is endodermal, intermediate between a
diffuse and a restricted form, and is stronger than that of either C. australis
or C. myrcia. The mesogloeal processes are longer than those of C. myrcva
and are slightly branched. The muscle becomes much stronger towards
the upper part of the body. I have failed to recognise the simple cir-
cumscribed endodermal portion of the upper part of the sphincter as
described and figured by Haddon.
The tentacles were described by Allman in 1846, and he was able
to recognise two kinds of nematocysts, the small oval nematocysts
which are very numerous and the large stinging cysts. Both kinds
have also been found in C. myrcia. The structure of the tentacle
(Fig. 15) is very much like that of C. myreia ; the knobs consist
almost wholly of deep ectoderm; the mesogloea and endoderm are
very thin, and the ectoderm consists of a mass of nematocysts, which
are long oval cells with the internal spiral coil showing perfectly. These
nematocysts did not stain, but appeared as highly refractive bodies
and are also present along the stems of the tentacles and in the ecto-
derm around the mouth. In C. myrcia the stems of the tentacles are
devoid of nematocysts, but they are found in the endoderm near the
tip of the tentacles in C. viridis ; they have not been mentioned as
occurring in the endoderm of any of the other members of this genus.
There is a distinct nerve layer at the base of the ectoderm, and that
COMPARATIVE ANATOMY OF SOME BRITISH ACTINIA. 547
of the stem contains nematocysts, but they are not so numerous as on
the tip. The nematocysts in the endoderm are not so numerous as those
in the ectoderm, and none are present in the endoderm near the base
of the tentacle. They are also present in the oval swelling at the tip of
the mesenterial filaments. The stomatodaeum is oval in section and the
wall is thrown into numerous deep and regular longitudinal folds. As
in C. myrcia, these folds show a rough approximation to the points of
attachment of the complete mesenteries. The ectoderm contains a large
Fic. 13.—Corynactis viridis. Vertical section through the
body-wall, showing the sphincter muscle.
number of gland cells, and near the base of this layer there is a quantity
of granular material. The mesogloea is thin except at the summit of
the folds, where it is thick and gives off small branches which form a
strong ectodermal muscle. The endoderm is spongy as in the column
wall, it is thicker than the mesogloea and contains large gland cells.
One gonidial groove is present, which is not very deep.
The number and. arrangement of the mesenteries vary in different
specimens. Transverse sections of three different specimens were cut.
In one there are 48 mesenteries, some complete and some incomplete,
548 OLWEN M. REES.
including two pairs of directives; in another there are 36 mesenteries,
including one pair of directives ; and ina third there are 46 mesenteries,
including two pairs of directives.
There are two cycles of mesenteries (Fig. 14), a primary series, consist-
ing of complete ones, and a secondary series in which they are incomplete.
The incomplete mesenteries project for some distance into the ccelen-
teron ; in section they are nearly as broad as the primary mesenteries.
The parieto-basilar muscle is stronger than that. represented in the
figure of C. myrcia and passes gradually into the retractor muscles. There
is a constriction of the mesogloea at the point where it passes from the
mesentery into the body-wall. The folds of the retractor muscles are
more numerous than those of C. myrcia, and consist of a number of un-
branched club-shaped processes which project into the endoderm.
A serial summary is appended showing anatomical characters of the
various species of Corynactis in so far as these data have been obtainable.
The ordering of tentacles and mesenteries, though frequently tetramerous,
appears to be highly variable, and, pending further study, these features are
omitted from the present summary.
Corynactis viridis, Allman, 1846 (British).
Sphincter (endodermal in all species) feeble and diffuse in the lower
part, stronger above, mesogloeal processes branched.
Mesogloea thin.
One cesophageal groove.
C. myrcia, Duchassaing et Michelotti, 1866 (Jamaica). Anatomical data
from Duerden.
Sphincter as in C. viridis, but weaker, mesogloeal processes unbranched.
Mesogloea thicker than the ectoderm. Endoderm thicker than in
C. viridis.
No cesophageal groove.
C. carnea, Studer, 1878 (Buenos Ayres). Anatomical data from Kwietniewski
[23]. Sphincter strong, fibres long and branching; mesogloeal pro-
cesses branched. Mesogloea about as thick as ectoderm, sometimes
thicker.
Two pairs of directives, grooves weak.
C. hoplites, Haddon and Shackleton, 1896 (Torres Straits). Anatomical data
from Haddon.
Sphincter strong but diffuse. Mesogloeal processes slightly branched.
Mesogloea about as thick as the ectoderm.
Two pairs of directives and one groove.
COMPARATIVE ANATOMY OF SOME BRITISH ACTINIA.
peal
ANT ap aga
Cust
Fic. 14.—Corynactis viridis. Portion of a transverse section
of the column in the region of the stomatodaeum,
showing one pair of directives and one pair of in-
complete mesenteries,
Fic. 15.—Corynactis viridis. Portion of
a transverse section of a tentacle,
showing the spiral coil in the nemato-
cysts.
549
550 OLWEN M. REES,
C. australis, Haddon and Duerden, 1896 (Australia). Anatomical data from
Haddon and Duerden.
Sphincter weak ; mesogloeal processes barely branched.
Parieto-basilar muscle very strong.
Mesogloea thicker than ectoderm above, thins downwards.
No distinct grooves.
C. Haddon, Farquhar, 1898.
C. gracilis, Farquhar, 1898.
C. mollis, Farquhar, 1898.
C. albida, Stuckey, 1909. Stuckey thinks all four may be varieties of one
species. Occur in New Zealand. The sphincter is practically absent.
These species do not appear to have been.
C. globulifera, Ehrenberg, 1834.
: Aas:
Oo Bodh gs EDs eum soe studied anatomically.
C. annulata, Verril, 1869.
Aureliania regalis (Andres).
Sub-Family. AURELIANID.
The following is the definition adopted by Dr. F. Pax in Kiikenthal,
Handbuch der Zoologve :-—
‘‘ Basilar muscle, ciliated bands, one siphonoglyphe, very strong cir-
cumscribed sphincter, longitudinal muscle of septa also very strong.
Simple and branched tentacles, in some cases placed on projections of
the surface of the mouth disk. Two or more tentacles communicate
with each exocoel.”’
Andres’ definition is formed from external characters. “ Base adher-
ing, column obconical, not tuberculate, imperforate. Tentacles arranged
in radial series, numerous and detached, not simple, but swollen at the
apices; the knobs usually spherical, sometimes giving rise to buds.
Colour yellowish red. Found in sand and on rocks.”
The Genus, AURELIANIA.
“Form: Base adhering, wide. Column abconical with minute
suckers secreting a membranous investment. Tentacles numerous,
arranged in radial series of two tentacles each, and at the same
time forming four circular cycles. Each of the cycles has a different
number of tentacles. The form of the tentacle is tubercular, swollen at
the apex, bilobed. Peristome convex, radially grooved. Colours yellow-
ish orange, tinged with vermilion.” The above is a translation of the
description of the genus Aureliania given by Andres in L’Attime. He
COMPARATIVE ANATOMY OF SOME BRITISH ACTINIA. 5d1
regards two species as belonging to this genus, namely A. heterocera and
A. regalis. A. regalis and A. augusta, Gosse 1860 and Andres 1880, are
given as synonyms. Andres in a note states that he found the number
of tentacles to agree with that in Gosse’s specimen. Since colour is too
unreliable a character on which to base species and since the comparative
anatomy of A. augusta, A. regalis, and A. heterocera still remains ap-
parently unknown, it seems necessary to retain the name regalis (Andres)
for the present, at the same time keeping in mind the possibility of
this name being merely a synonym of A. augusta (Gosse). The name
regalis is used in France, from which coast the specimen referred to
here was obtained. Figs. 4, 5 and 6, in Plate X in L’Attime, give
an exact reproduction of the form and colour of the specimen when
alive.
The following is a translation of Andres’ description :—
“ Form: Base adhering ; spreading, irregular. Column conical below,
cylindrical above, smooth, fleshy, not greatly extensible, secreting
abundant mucus to form a sheath. Margin turning upwards, minutely
crenate, collar deeply grooved. Disk small,smooth. Tentacles retractile,
numerous (144) in four cycles (36+36+36+36). [The tentacles may
be more than 144 in number ; in one specimen I found 168 (42+42-+-
424-42) as in A. augusta (Gosse).| Each tentacle is short, moniliform
and directed outwards. They occupy more than half the periphery of
the disk. The form, ‘ monile” (resembling a necklace), is modified in
the tentacles of the two external cycles, the swellings are unequal, the
proximal is rounded and the apical is prolonged to a point. The peristome
is smooth, scarcely striated at the radii. Mouth round, small, not
prominent.
“Colour pale rose. Column orange-vermilion with whitish specks.
Tentacles of indefinite yellowish colour, transparent with opaque stains
and spots. Peristome reddish vermilion. Of the gonidial radu only
one is indicated, and this has a whitish line where the radius touches the
periphery. Situation in the sand usually covered as far as the disk, but
sometimes protruding with part of the column.”
Andres examined three individuals, two coincided with the above
description, but the third had the peristome spotted.
I took the following measurements from the preserved specimen :—
Diameter of base=17 mm.
Height of column=18 mm.
Diameter of oval disk greatly contracted=9 mm.
552 OLWEN M. REES.-
The specimen contained a large amount of mucus, this caused the
tissues to contract and become very hard in xylol. The specimen had
become very much contracted ; for these reasons I am unable to give a
full description of the species. The mesenteries are arranged in two
cycles, 36-++-36=72. The incomplete mesenteries are unevenly developed,
some appear as slight projections into the ccelenteron, others are larger
and have produced many muscle folds.
The mesenteries (Fig. 16) possess a very long retractor muscle with a
large number of short folds. The curious fact about this muscle is that it
faces the intramesenterial space or exocoele instead of the intermesenterial
space or endocoele, as is commonly found in Actinians. The longitudinal
muscle of the directives faces the intermesenterial space. Near the
proximial end of the mesentery lies the parieto-basilar muscle, which arises
as a stout projection on the side away from the retractor muscle. It gives
off a large number of folds which are longer than those of the retractor
muscle, they have a somewhat reticulate appearance when examined
under the high power of the microscope. The mesogloea is fibrous and
has a number of cavities of irregular shapes. The wall of the cesophagus
is raised into a number of lobes. There is one cesophageal groove corre-
sponding to the pair of directive mesenteries present.
The body-wall is strong, the mesogloea forming a thicker layer than
the ectoderm. The latter is raised into a large number of folds, each
being supported by a process of mesogloea.
This species is extremely rare, and British specimens were not available.
One specimen of Aureliania regalis was, however, most kindly sent by
Monsieur Louis Fage from the laboratory at Banyuls-sur-Mer, and it is
this specimen which has been anatomised and is described above.
INDEX TO LETTERING.
ect., ectoderm. | mes., mesogloea.
ect. m., ectodermal muscle. mu., mucus.
end., endoderm. | n.J., nerve layer.
end. m., endodermal muscle. nem., nematocyst.
end. sp. m., endodermal sphincter pb. m., parieto-basilar muscle.
muscle. r.m., retractor muscle.
g., granules. sph., sphincter.
gl. c., gland cell. zoox., zooxanthellie.
COMPARATIVE ANATOMY OF SOME BRITISH ACTINL“. 553
Fic. 16.—Aureliania regalis. Transverse section
of the column, showing a portion of one of
the mesenteries.
NEW SERIES.—VOL. X. NO. 4, MAY, 1915. 2N
554 5. OLWEN M. REES.,
BIBLIOGRAPHY.
[1] 1846. Atuman, G. J. Biological Contributions. Corynactis. Ann. and
Mag. of Nat. Hist. Vol. XVII.
[2] 1865. Gossz, P. H. On Aigeon alfordi, a new British Sea-Anemone,
Ann. and Mag. of Nat. Hist. Vol. XVI. 3rd Series. No. XCI.
[5] 1875. Hertwig, R. Report on Actiniaria dredged by H.M.S. Challenger.
[4] 1883. Anpres, A. L’Attinie, Fauna et Flora Golf Neapel.
[5] 1887. McMourricu, J.P. Report on Actiniaria collected by the Albatross.
Smithsonian Institute, U.S. Nat. Mus.
[6] 1888. Drxon, G. Y. 1. Remarks on S. venusta and S. nivea.
[7] 2. On the Arrangement of the mesenteries in the
genus Sagartia.
Proc. R. Dublin Soc. Vol. VI.
[8] 1889. Happon, A. C. Revision of the British Actinie. Part I.
Proc. R. Dublin Soc.
[9] 1893. Carlgren, O. Studien tiber Nordische Actinien. Svenska. Ak.
Handl.
[10] 1896. Happon, A. C. and J. E. DueRpEN. Actiniaria from Australia
and other districts.
Proc. R. Dublin Soc. Vol. VI. Series II. No. 6.
[11] 1898. Happon, A.C. Actiniaria of Torres Straits.
Trans. RK: Dublm-Soc> Vol--Vik Ser: Ti? SNov iG:
[12] 1898. Farquhar, H. Preliminary Account of some New Zealand
Actiniaria.
[13] 1900. DurErpen, J. E. Jamaican Actiniaria. Part II. Stichodactyline
and Zoanthee.
Vol. VIL. Ser Al. Nos6;
[14] 1901. Deuace, Y. et E. Hérouard. Zoologie Concrete. Tome II.
[15] 1908. Sruckry, F. G. A. 1. Review of New Zealand Actiniaria.
[16] 2. Anemones found in the neighbourhood
of Wellington.
Trans. N.Z. Institute. Vol. XLI.
[17] 1908. Watton, C. L. 1. Notes on Sagartide and Zoanthide from
Plymouth.
[18] 2. Actiniz collected by 8.8. Hualey.
Journ. Mar. Biol. Assoc. Vol. VIII. No. 2.
[19] 1909. Kirx,-H. B. and F. G. A. Sruckry. Two species of Actiniaria
from Campbell Island.
Sub-Antarctic Islands of New Zealand. Article XVIII.
[20] 1910. Pax, F. 1. Studien an westindischen Actinien. Zool. Jahrb. 1910.
[21] 2. ** Hexacorallia,’ in Kiikenthal, Handbuch der
Zoologie.
[22] 1912. Pax, F. Les Actinies de la céte du Pérou (Breslau).
Mission de l’Equateur, t. 9, fasc.4. Paris, Gauthier Villars.
[23] 1896. Kwrernrewsxr, C. R. Revisicn der von Studer gesammelten
Actinien. Jenaische Zeitschrift XXX, p. 599.
[ 555 ]
Notes on Experiments in the Keeping of Plankton
Animals under Artificial Conditions.
By
L. R. Crawshay, M.A.
TABLE OF CONTENTS.
Introduction . ; : : 3 F : : é : - - - 555
The experiments. : : ‘ : ‘ 5 . 559
Results obtained in Boseione A and Ber. 5 5 - 6 5 - 6 8
Zoaeae . : : : - : - 5 - 5 ss
Calanus pemaechicas 3 Ay a isn ee é : : ¢ 0 Sa)
Temora longicornis . : : : . : : - < - . 560
Anomalocera Patersoni . ‘ 5 ; : : : 5 A . O61
Acartia sp. : é Wl ee : : : 3 6 4 - ty aoe:
Young Calanoids . : F : : ; : . : c les
General . i ? ‘ : : ; : : - 962
Special experiment in Position A : . : - : anes
Results obtained in Position C : : : : : : : < . 563:
Pseudocalanus elongatus . : : c - - - - . . 564
Calanus finmarchicus F ; 3 : : : é < 0 . 565.
Acartia sp. . : : ; : : ‘ . 566
A comparison of C seals with is pad B aa
Generalremarks . ; : : - é 2 . a . 568.
On Diatom growth in the Seer niont: ae : eon
The influence of some Bacteria on the eeanents oad whee despruchion : - O72)
Introduction.
THE experiments referred to in the following pages were carried out by
the wish of the Director at the Plymouth Laboratory, between June,
1912, and February, 1913. They were undertaken with a view to keep-
ing under observation some of the smaller zooplankton, and particularly
the Copepoda, in order that they might be followed through the
different stages of their life cycle. After a long series of disappointing
results, the experiments were unavoidably interrupted at a time when
apparently the chief obstacles to success had been located and largely
overcome.
Continued observation of these small animals has only in the last few
years been rendered certainly possible by the work of Dr. Allen on the
culture of the marine Diatoms, which form the chief food supply of the
great majority of them, and it is not surprising that until the problem of
obtaining and keeping a suitable food culture was settled, attempts to keep
556 L. R. CRAWSHAY.
Copepoda alive in the Laboratory met with little success. Mention may
here be made of one important result obtained by Dr. Allen himself,
in the course of his Diatom experiments. Ina flask of 1000 c.c. in capacity
he kept, between August and September, 1905, some specimens of
Calanus finmarchicus alive on a mixed Diatom culture for a period of
about seven weeks, and obtained from them many nauplii, two of which
developed into young Calanus, of which the exact life period was not
recorded.* It was uncertain how far the exact conditions under which
this experiment was carried out had been essential to its success, and
with a view to locating harmful influences and removing them as they
became apparent, the experiments came to be conducted under many
different conditions in regard to position in the Laboratory, the kind
of vessel employed and its capacity, the water used, the intensity of the
light, the food culture, and the presence or absence of an air supply.
Attention was also given to the question of the influence of some of the
Bacteria and their destruction. Only after a large number of experi-
ments had been made was it ascertained that due consideration had
not been given to a factor, the importance of which cannot be over-
estimated, namely, temperature, and that to irregularities of temperature
the repeated failure of the earlier experiments was without doubt to be
attributed in a very large degree. The work which has since been re-
sumed still needs careful attention to details of method before satis-
factory results can be obtained, and in the meantime a short account
of the experiments is given as a preliminary contribution to the subject.
The experiments will be considered, as far as may be, in the order
in which they were carried out, while grouping them together according
to different conditions, some reference to which is first necessary.
Position.
(A) In this room, where most of the earlier experiments were
made, the aspect is north and the light moderate. The window was
at all times kept partly open, and no artificial heating was used ; conse-
quently the experiments were very susceptible to outside changes of
temperature that occurred from one day to another. Records of the
temperature of the water of the experiments were not made till the
latter part of November, but twenty-five observations made between
November 26th and January 13th showed a varying range of 6° or more,t
a maximum daily variation of 3-8°, and a maximum change over two
* Journ. Mar, Biol. Assoc., N.S., Vol. VIIL., p. 470.
+ All temperatures are recorded in degrees Centigrade.
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. Ba.
days of 5-8°, the average temperature being 10-8°. During the summer
months, the changes must have been very much greater.
(B) Here the vessels rested on a table close to a large double
window, with a western aspect, partly lighted also from the northern
side, and the light was consequently good. The position in the building
being more central than Position A, the changes in temperature were
probably, on the whole, less in extent and less sudden than in the latter.
At times, however, they were greater, as, for example, in the month of
July, when on four successive days the following temperatures of water
in the bell-jars were recorded : July 17th, 25°; July 18th, 20°; July 19th,
163°; July 20th, 17°.
(C) In this part of the building, the General Laboratory, well lighted
with large windows, both on the southern and on the northern sides,
the light obtained was always good, and often so strong as to need
screening. In the colder weather the air temperature is kept by hot-
water pipes between 13° and 18°, and in general it is subject to
very much less change than in either of the other two positions. As,
however, in all experiments here carried out, the vessels were kept sub-
merged, either in the sea-water of the general circulation or in water
artificially adjusted to a nearly constant temperature, the changes in
air temperature were of minor importance and, as affecting the experi-
ments, almost negligible. The water of the experiments, which was
necessarily regulated by the temperature of the tank water, showed
over a number of observations made between November 26th and
February 7th a varying range of no more than 1-6°, a maximum daily
variation of 1°, and an average temperature of 12:3°.
Vessels,
These consisted chiefly of the following :-—
Glass Finger-bowls. Capacity, 350 c.c.
iilasks: se. land 1-o: litres:
7 ars: 5» 2 litres.
», Beakers. ee eee,
», Bell-jars. at (8 lea
The vessels were covered with squares of glass or with watch glasses,
as a provision against dust. Except in one special experiment (p. 562),
there was no circulation of water through the vessels, the water being
left standing, subject only to stirring by aeration or otherwise, and
being only changed in certain occasional instances.
558 L. R. CRAWSHAY.
Water.
(A) Tank Water.—Water circulated through the tanks of the Labora-
tory from the supply stored in the reservoirs. This water is pumped up
into the reservoirs from the sea below the Laboratory at high water
spring tides. In consequence of the large number of animals living in the
tanks it contains a considerable amount of excretory products.
(B) Berkefeld Water.—Tank water treated with animal charcoal, and
filtered through a Berkefeld candle. In many experiments, owing to the
high salinity of the tank water, this was diluted with 5% distilled water.
(C) “ Outside’? Water.—Water brought in from outside the Plymouth
Breakwater, and largely free from the contamination of the imshore
grounds. This was used sometimes untreated, sometimes sterilised, and
sometimes filtered through a Berkefeld candle.
(D) Miquel Sea-Water.—Occasionally Berkefeld, usually “ outside ”
water, treated with the modified Miquel solution employed by Allen and
Nelson,* but chiefly used in considerably less strength, generally one-
third, in experiments here to be considered.
Light.
Additional illumination was obtained when necessary by placing sheets
of white paper or card, or of opal glass, under the vessels, and in
many cases behind them also. In some experiments the hght was
partially or wholly cut off by screening the vessels with black paper.
Food.
In most of the experiments a culture of the Diatom Netzschia clostervwm |
was used as food for the animals. In some, the Alga Chlorodendron
subsalsum was used. |
Air-supply.
Artificial aeration of the water was employed at intervals in many of
the experiments for varying periods, and sometimes continuously, by
means of drawn-out glass tubes led into the vessels, and connected with
the general air-pressure system of the Laboratory. It may be said at once
that no definite advantage seemed to be gained by its use, assuming the
water to be naturally aerated at the outset.
* Journ. Mar. Biol. Assoc., N.S., Vol. VIII., p. 428.
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 5
Ou
le)
The Experiments.
For brevity, the results of the experiments will be considered in a
summarised form, the experiments being grouped together according to
the vessels in which they were carried out. The recorded averages and
maxima refer to the life period in days occurring among animals of the
several experiments in each group. The experiments carried out in
Positions A and B, in all of which the vessels were exposed to the in-
fluence of air temperature changes, will first be dealt with. Later, the
experiments in Position C, in all of which the vessels were submerged,
will be treated in the same manner, and the results of these will then be
compared with those in Positions A and B. The dates given are those
on which the different experiments were started.
Positions A AND B.
In the experiments to be referred to, all but those made in 11-litre bell-
jars were carried out in Position A. The results are marked with great
irregularity. In certain exceptional cases, specimens lived for a con-
siderable period, but the averages are almost consistently low, and it is
evident that some factor entered into all the experiments which rendered
the conditions unsuitable and in most cases quite intolerable. In some
preliminary experiments in tank water, to which no Nitzschia or other
food was added, rather lower averages occurred, but in other respects
no distinct advantage was traceable to the kind of water used, which
included Berkefeld, Berkefeld diluted, the same with Miquel-Allen
solution in full proportions, “ outside ” water untreated, and the same
sterilised. Some species appear to be more delicate than others, and
among naupli the mortality was exceptionally high. The different forms
will, therefore, be considered separately.
Zoaeae. These should perhaps be viewed in a different category from
the rest, since it is doubtful whether a suitable food was found for them,
though Nitzschia, Chlorodendron, and Cilate cultures were tried. In a
total number of 18 experiments with from 4 to 11 specimens, in finger-
bowls (June 11th to July 30th), the average time of survival was from
5 to 7 days, the maximum ranging from 11 to 16 days.
Calanus finmarchicus. In finger-bowls, 5 experiments comprising
from 5 to 12 specimens (June 19th to August 7th) showed in Berkefeld,
Berkefeld diluted, and Berkefeld diluted plus Miquel-Allen solution,
comparatively little difference of average, 11 to 14 days, from that of
3 experiments in tank water (10 days), to which no Nitzschia or other
560 L. R. CRAWSHAY.
food was added. Apart from one exceptional example in which a speci-
men, infected with the parasite Microniscus, lived for 40 days, the
maximum was no higher than 23 days, which was 4 days in excess of the
next highest period.
In 1-litre flasks, 5 experiments in “ outside” water, containing from
3 to 5 specimens (September 27th to October 23rd) showed a higher
average, of about 22 days, than was obtained in the finger-bowls, and
a much higher maximum of 84 days. In the experiment in which this
high maximum occurred (October 21st) the shortest life period was
23 days, and the average for the three individuals was about 44 days.
No clear explanation was found for the fact that in three other Calanus
experiments, started two days later under almost identically similar con-
ditions, the maximum was no higher than 27 days, and the average
about 16 days.
Temora longicornis. In finger-bowls, 9 experiments with from 6 to
12 specimens (June 19th to August 8th) were far less successful than
in the case of Calanus, and.a maximum of 23 days, which was obtained
in one case in Berkefeld water, was far in excess of the life period
that was usually sustained. The data for averages are incomplete, but
with the exception mentioned the longest life did not exceed 11
days, and the average for all the experiments was probably not above
5 days.
In 1-litre flasks, 2 experiments, with 7 and 10 specimens, in sterilised
“ outside ” water (September 18th and 27th), were little more successful
than those in the finger-bowls, the maximum being about 17 days, and
the average life probably not exceeding 5 or 6 days. In connection
with the mortality of this species, it is very remarkable that in the first
of these two experiments, 6 Acartia which were included in the same vessel
at the same time subsequently reached the high average of about 60
days.
In 11-litre bell-jars (Position B), an experiment with 70 specimens,
in Berkefeld water (July 17th) failed completely, all dying within two days.
Of a similar number, placed in the same bell-jar with the same water
(July 19th), none lived for more than about a fortnight. In an experi-
ment with 50 specimens in “ outside’ water (July 17th), a few only
survived the first fortnight, though a single specimen lived for 48 days.
Mention has already been made (p. 557) of the irregular and high
temperatures that were recorded for the water in bell-jars in this position
at this period, showing over four successive days a range of nearly 9°,
with a maximum daily variation of 5°, and these irregularities were
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 561
with little doubt accountable for the mortality of specimens, even in
so large a volume of water.
Anomalocera Patersoni. In finger-bowls, 2 experiments with 6 and
3 specimens, were made in tank water only, to which no Netzschia or
other food was added (June 10th). These 9 specimens showed an aver-
age of 2 days only, the maximum being 4 days.
Acartia sp. In a I-litre flask, a single experiment with 6 specimens
in sterilised ‘ outside ” water (September 18th) showed the high maxi-
mum of 100 days, the average being about 60 days. This was the only
experiment carried out in Position A in which nauplii were certainly
produced, a few of these being observed continuously from the 30th
to the 73rd days. The number of nauplii produced, and their individual
life periods are uncertain. No more than four were recorded at any one
time. Some showed distinct growth, but none reached an advanced
stage. As it has been stated, 7 Temora which were included with these
Acartia, all died within about 17 days, and it would seem on the evidence
of this single experiment that the species (probably A. Claust) is more
hardy than Calanus or Temora. The experiment lasted till December
27th.
Nauplii (chiefly Balanus, Temora, and Calanus). In finger-bowls,
3 experiments with from 15 to 20 specimens in Berkefeld water (July
11th) showed a maximum of 4 days ; in 3 experiments, with from 20 to
100 specimens, in Berkefeld diluted (July 19th to 30th), the maximum
was about 15 days ; in 2 experiments, each with 20 specimens, in Berke-
feld diluted, plus Miquel-Allen solution (August 8th), the maximum was
about 12 days. The average for all these experiments probably did
not exceed 2 days. On the other hand, as it has been shown, among the
Acartia nauplii hatched from eggs laid in the vessel, some appear to have
lived for a considerable time though the individual hfe periods were
not known.
Young Calanoids. In 1-litre flasks with several young forms naturally
contained in this bulk of “ outside ’
food included, 2 experiments (September 24th) showed a maximum
>
water, and with no additional
life period of 18 days only.
In a bell-jar (Position B) an experiment in Berkefeld water with
mixed plankton including many young forms, and with some fine tow-
netting added as food (June 10th), showed several young forms, including
nauplii, alive and healthy on the 33rd day, and a few continued till the
42nd day. Soon after this all disappeared, the specimens apparently
562 L. R. CRAWSHAY.
failing, hke others previously referred to, in consequence of high and
irregular temperatures at the time in this position.
General. As bearing on the sensitiveness of some Calanoids to sudden
changes in the water conditions, the following example is important.
On June 15th, two Calanus finmarchicus were given to me by Mr. Fuchs in
a large jar (breffit) of 2000 c.c. m capacity, in “ outside ” water contain-
ing a growth of Netzschia, in which he had reared some Hchinoplutei.
The culture had been started by him on April 19th, and kept from that
date on one of the slate slabs in the General Laboratory. In the water
that was used the two Calanus had been introduced unobserved, evidently
as young forms, possibly as naupli, and these, feeding on the Netzschia
culture, had grown to nearly full size. On June 15th the jar was taken
over by me and placed in Position A, where the Calanus continued
healthy until July 9th. The Netzschia having then grown too thick the
Calanus were transferred to a new culture in Berkefeld water, in a clean
jar. One specimen was stunned by the change, and fell to the bottom,
remaining almost motionless afterwards, and both died within two days.
The temperatures had been taken, and Mr. Matthews having kindly
analysed samples of the water and ascertained the densities, the change
of conditions from one jar to the other proved to have been as follows :—
T. 8.7 &
Jar A. “ Outside’? water 16:5 35-22 25-82
Jar B. Berkefeld ra 17-5 31°94 27-68
The temperature change being one of only 1°, it seemed evident that
the death of these Calanus was to be attributed to a sudden change of
2-72 in salinity, and owing to this the Berkefeld water subsequently
used in the experiments was diluted with 5°% distilled water. It was
thought that by thus obviating such sudden changes in salinity, much
of the difficulty previously encountered in the experiments might be
overcome. It was not realised till later that repeated changes in the
air temperature communicating themselves less suddenly to the water in
the exposed vessels might be equally harmful in their effects. .
Special Experiment in Position A.
In the latter part of the year, it became increasingly evident that some
factor which had escaped observation was a constant source of harm to
the animals. In view of the possibility that this might be the presence
of Bacteria, several experiments, which will be referred to in detail
later, had been made in keeping Copepoda in the presence of strong cul-
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 563
tures of Bacteria raised on peptone. But the results of these experiments
showed that species were capable of tolerating such conditions to a much
greater degree than was expected, and did not bear out the supposition
that bacterial infection had been the primary cause of failure. Experi-
ments also made with and without an air-supply gave no definite evidence
of the value of an air-supply as improving the conditions in water that
was naturally aerated at the outset.
There remained a possibility that harmful conditions might be pro-
duced through the accumulation of excretory products in the vessels,
and to test this a special experiment in Position A was arranged, by
which a constantly chatiging supply of water and food was passed
through the vessel in which the animals were contained. For this pur-
pose a large bottle, of 10 litres in capacity, was filled with sterilised
“ outside” water, with Miquel-Allen solution in proportions one-third
of those used by Allen and Nelson, and this water was infected with a
culture of Nitzschia. The vessel of the experiment, in which 5 Calanus
were placed, was a 1-5-litre flask, and into this the supply was led by a
glass tube from the large bottle, the apparatus being arranged in the
form of a self-regulating siphon, by which the water in the flask was
kept at a constant level. From close against the bottom of the flask,
a siphon tube was led out from the flask to the exterior, to serve as a
waste pipe, and this, drawing on the contents of the flask, was so ad-
justed by a screw clip that the water and food-supply was made to pass
through the flask at the rate of 1 litre per diem, nearly. An air-supply
was also provided at a slow rate in the flask by connection with the air-
pressure system of the Laboratory. A good light was ensured and, the
food growth being strong, the conditions were such as appeared to
meet all requirements. But little improvement was shown in the result
of this experiment which, though more successful than most of the
previous ones, produced only a maximum life of 28 days, and an average
of about 21 days, the shortest life being 14 days. This experiment was
started on October 16th, 5 days prior to the commencement of an ex-
periment made in the same position, in a 1-litre flask under the ordinary
conditions, in which 3 Calanus subsequently showed a maximum of 84
days, and an average of 44 days (p. 560).
Posrrion C.
It had in the meantime been observed that a Calanus which had
been left in a 2000 ¢.c. jar, partly submerged in one of the tanks in the
General Laboratory on August 28th, was still alive on October 18th,
564 L. R. CRAWSHAY.
51 days later, and, soon after the close of the special experiment just
described, a new series was started with the vessels submerged up to the
neck in the same manner. An improvement in the results soon became
apparent, and from this time the experiments were continued under
these altered conditions, either in one of the tanks or in a small extem-
porised reservoir of water.
In the first experiment, with 6 Temora, in a 2-litre jar of water, with
Chlorodendron as food, one specimen only was alive on the 19th day, and
this did not live for more than a few days afterwards. These Temora,
however, had been left standing for 7 days previously, in a beaker in
Position A before the experiment was started; and the result was there-
fore of doubtful value.
The other experiments related chiefly to Pseudocalanus elongatus and
Calanus finmarchicus. The water used was in all cases “ outside ”
water, treated with one-third Miquel-Allen solution and filtered through
a Berkefeld filter. In the majority of the experiments the food was
Nitzschia ; in a few cases Chlorodendron was used. Exact data for
averages are wanting, and the results can only be considered in their
main details. In many cases the observations were unfortunately inter-
rupted before the complete records had been obtained. The results may
be summarised as follows :—
Pseudocalanus elongatus. In 2-litre beakers, 3 experiments, each
with 15 specimens (November 11th to 28th), showed on the 44th, 50th,
and 5lst days, severally, about 23 survivors. In one of these experi-
ments, the water having been changed on the 44th day, four were still
living on the 72nd day. In another a change of water on the 51st day
led to bacterial infection, with fatal results to all the specimens very
soon afterwards. In the third, one specimen was still living on the
121st day.
In an uncompleted experiment with 20 specimens (December 20th)
a few were still living on the 50th day.
Two experiments (Nos. 174 and 175), which failed through injury caused
in connection with an air-supply, are referred to below.
Naupliw were obtained in all the experiments with Pseudocalanus, their
presence and growth being observed over periods which varied from
40 to 63 days in the different experiments, omitting the two experiments
last referred to. Data concerning individual life periods are not avail-
able, but several were recorded as reaching the adult form and, in a few
cases, apparently the full growth, the age at which the adult stage was
reached being approximately between 35 and 40 days.
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 565
In the experiment in which the loss of the specimens was attributed
to bacterial infection, bright carmine patches appeared colouring the
dead bodies of the specimens, other objects at the bottom of the vessel
being suffused with the same colour. Mr. Harold Drew kindly tried to
cultivate the Bacteria on peptone agar, but no growth was obtained.
The circumstances of the failure of the two experiments (November
30th) in connection with the use of an air-supply are as follows :—
Each experiment concerned 20 specimens.
(No. 174.) Till the 14th day, several were seen very active, and on
this day from 20 to 30 nauplii were observed. On the 15th day, all the
nauplii and nearly all the adults were dead. On the 19th day, only one
of the adults remained alive, showing little movement, on the bottom of
the vessel.
(No. 175.) On the 14th day, about a dozen adults and a few nauplii
were seen. No subsequent records were made till the 19th day, when
nearly all were dead. On the following day a few nauplii still survived,
but these died soon afterwards.
In these two experiments the vessels had been provided with an air jet,
forced through the water by connection with the air-pressure system of
the Laboratory, during the 24 hours between the 13th and 14th days.
When on the 14th day the air-supply was taken off, and the vessels
removed from the tank for examination, they remained exposed for
about half an hour to the much higher air temperature of the Labora-
tory. The rise in the temperature of the water thus caused was not
observed, but it seems possible that the air-saturated water of the
vessels thus parting rapidly with air in solution, injury was caused
to the blood system of the animals.
Calanus finmarchicus. In 2-litre beakers, submerged in the tank,
5 experiments (November 30th to January 13th) resulted, as far as the
observations were carried, as follows :— |
Max. Period of Life Average,
Experiments, Specimens, Recorded, days. days.
1 Ae 2 Se 48 ane 35 (completed)
1 aes 5 see 27 aoe 19 9
1 ee 3 dee 64 ob: 41 (uncompleted)
2 re ... About 6 living on 45th day -
Ova were obtained in the last two experiments, but were lost through
an accident.
In 1-litre flasks submerged in a bath heated over a small bunsen flame
to 16°-18°, and kept by a regulating thermometer at this approximate
566 L. R. CRAWSHAY.
temperature, five experiments (January 13th to 29th) showed the following
results up to the time when the observations were interrupted :—
No. Date. Specimens, Adults. Remarks.
195 Jan. 13th 3 All living on 12th day ( Many Nauplii seen be-
(and apparently on tween 6th and 26th
26th day). days.
One Nauplius on 4th
198 sy) Roth 3 All living on 20th day. day. None seen on
20th day.
200 » 24th 3 Iwo’, a; |lGthiday | Oye oe Seon DR bh
Water infected by Bac-
201 i Batis 4 All dead on 5th day. teria forming long
white strands.
ano : Reiaot ; f About 7 ova seen on
202 » 29th 3 Two living on 30th day. 1 1ith day.
Omitting the experiment which failed through bacterial infection, the
mortality was small at the time when the observations were interrupted,
two deaths only having been recorded among the twelve specimens over
a period averaging at least 20 days and probably 23 days, in the different
experiments.
Ova were obtained in all these experiments, and nauplii were recorded
in two of them, many occurring in one over a period of 20 days.
Acartia sp.* In a 1-litre flask, submerged in the artificially heated
bath, a single experiment was made (December 20th) with 5 specimens.
On the 40th day three of these were living. Nauplii were first observed
on the 23rd day, about a dozen were seen on the 25th and 32nd days,
and a few only on the 40th day.
A Comparison of the Results obtained in Position C with those obtained
in Positions A and B.
The experiments with Pseudocalanus having all been made in Posi-
tion C, the results obtained with this species must be treated with some
reserve when comparing them with those obtained for other species in
Positions A and B, and it is better to consider them only as confirming
the evidence of the experiments with Calanus and the single experiment
with Acartia.
For Acartia, the only experiment in Position A gave the high maxi-
mum of 100 days, and an average of 60 days for the 6 specimens. In
the uncompleted experiment in Position C, 3 out of the 5 specimens
were still living on the 40th day. The combined life period of the young
* Probably A. Clausi. The species was not certainly determined.
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 567
was in the former case 43 days, and in the latter 17 days when the last
record was made. It is only noticeable that in Position C the fertility
of the parents was distinctly higher than in Position A. It seems
probable that the species is hardy as compared with others and less
susceptible to injury from changeable conditions (cf. p. 561),
For Calanus, the comparative results are as follows :—
Posrrion A.
(1) Finger-bowls. Max, for 5 experiments (34 specimens), 40 days. Avg. 12 days.
(2) 1-litre flasks. Ee ienaat ee (19 ee by Oe as ey i:
(3) Special expt. bs 1 Fa (5 a Perc mats Se
Average for 11 experiments, 17
”
Position C.
(1) 2-litre beakers. Max. for 2 completed exps. (7 specimens), 48 days. Avg. 27 days.
Of 3 uncompleted experiments, one with 3 specimens showed at the time of
the last record an average of 41 days; the other two, with 8 specimens,
showed on the 45th day an average of 40 days.
The average for these 5 experiments then exceeded 35 days.
(2) 1-litre flasks. The 4 experiments (12 specimens) were very incomplete at the
time of their interruption, only one death having occurred in each of two
of them, on the 16th and 30th days respectively, or over a period averaging
in the 4 experiments not less than 20 (or 23) days.
The 5th flask experiment is omitted from consideration here. The
Bacteria by which the water became infected appear to be comparatively
uncommon, and, if the general form of the strands produced by them can
be relied on as characteristic, they were only twice observed, each time
with fatal results to the animals.
Disregarding the last experiment, it may reasonably be estimated that
the average for the 4 experiments with Calanus in 1-litre flasks would
not have been less than that shown by the 5 others in Position C at the
close of the observations, viz., 35 days,
In regard to experiments in Positions A and B generally, the early
falling off of specimens is noticeable in nearly all the results, thus :—
For Temora, the average of 9 experiments in finger-bowls was not
more than about 5 days ; that of 2 experiments in 1-litre flasks was about
the same ; in 2 experiments in 11-litre bell-jars, few survived the first
fortnight.
With Anomalocera, the 2 experiments with 9 specimens in finger-bowls
showed an average of 2 days only, with a maximum of 4 days.
With Nauplii, especially those of Balanus, Temora, and Calanus,
introduced direct from the townettings into finger-bowls, the mortality
568 L. R. CRAWSHAY.
was very high, none living for more than about 15 days, and the
average for 8 experiments probably not exceeding 2 days. The few, on
the other hand, obtained in the course of the experiment with
Acartia, lived for a considerable time. In a few experiments in
Position A with mixed plankton kept in its natural proportions, in the
water that contained it, from 1 to 3 nauplii were observed alive in 3
different experiments in 1-litre flasks, after 11, 11, and 17 days severally ;
their continuance in these cases being possibly due to the absence of the
initial change of water that was made in the ordinary experiments. On
more than one occasion, when nauplii were transferred from townettings
to water of a different (higher) temperature, they were seen to be tem-
porarily stunned by the change, and to fall to the bottom of the vessel,
though usually recovering within some 5 or 10 minutes afterwards.
Young Calanoids generally, included with some mixed plankton m an
11-litre bell-jar of Berkefeld water in Position B, showed a comparatively
high maximum in this larger volume of water, several, including nauphi,
surviving on the 33rd and a few on the 42nd day.
There remain for consideration the experiments in Position C with
the species Pseudocalanus elongatus, for which unfortunately there are
no comparative data in the other positions. Of the 6 experiments which
have been referred to, 2 may be omitted in which a sudden failure was
attributable to the use of an air-supply. In 3 of the remaining 4 ex-
periments, about 50°% of the total number of specimens were alive on
the 50th day, some being afterwards recorded considerably later ; in the
4th probably 30° were alive on the 50th day. Young, which were
obtained in all the experiments, were recorded in these four over periods
ranging from 40 to 63 days in duration, one or more in each case reaching
the adult stage.
General Remarks.
While it is not improbable that other adverse causes, in addition to
that of changeable temperature, contributed in some measure to the
generally unsuccessful results of experiments in Positions A and B, it
is difficult to trace them with any consistency, or to attribute the failure
of the animals to any single chief cause other than the fluctuations of
temperature occurring in vessels which were directly exposed to air
changes.
Experiments with some of the common putrefactive Bacteria, culti-
vated on peptone, in no way bore out a supposition that the presence
of such Bacteria, and their fouling effects on the water, had exercised any
important influence on the progress of the experiments. The possibility
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 569
of infection by Bacteria of a different nature, such, for example, as the
two forms referred to (pp. 565, 5€6), must of course be considered. But
such forms as these were rarely observed, nor did the very irregular rate
of mortality among individuals in an experiment, or in different experi-
ments, suggest that bacterial action was primarily accountable for the
death of the specimens.
Food-growth again, was in many cases poor and uncertain in experi-
ments in Position A, but as the food-supply was with few exceptions
renewed at frequent intervals, it seems unlikely that the animals were
much affected by any such deficiency. It was often observed, too, that
when food-growth was vigorous the animals died off independently of
this, or even earlier than in experiments in which the growth was poor
or stationary.
A noticeable feature occurs in connection with the special experi-
ment in Position A (p. 562), in which, apart from temperature, apparently
ideal conditions were provided, and a healthy growing food culture was
carried in the changing water-supply through the vessel in which the
animals were contained. This vessel was a 1-5-litre flask, and it is remark-
able that the average life of the 5 Calanus it contained was very nearly the
same, 21 days, as that for the 19 specimens of the 5 experiments with this
species in 1-litre flasks in the same room, 22 days. In the 5 experi-
ments with 34 specimens in finger-bowls, in which the volume of water
was no more than 300-350 ¢.c., the low average of 12 days is presum-
ably attributable to the changes communicated by the air temperature
being more rapid than in the case of the larger vessels. If an instan-
taneous change of temperature, probably of 4° or 5° (p. 568), can so
affect nauplii as to stun them for 5 or 10 minutes, or if one, apparently
of salinity only, can be fatal, as in the case of the 2 Calanus referred to
(p. 562), it is reasonable to suppose that the daily fluctuations of air
temperature to which uncovered vessels are exposed are lable to produce
conditions that must sooner or later prove fatal to animals so sensitive
to such changes.
The removal of the experiments to Position C was especially prompted,
as it was observed, by the survival of a Calanus for 51 days in a 2-litre
jar submerged in one of the tanks. This specimen was then found to have
the hairs of the antenne and caudal rami much encrusted with fixed
Diatoms and other accretion, and probably succumbed owing to these
causes about a week later. This jar contained a sample of water only,
with the plankton naturally present in it, and therefore very few indi-
viduals at the outset, nor was any addition made to the food. Yet on
NEW SERIES.—VOL. X NO. 4. MAY, 1915. 20
570 : L. 'R. CRAWSHAY.
‘the 29th day there were seen alive in it, besides the adult Calanus, a
few small ones, and one or two Temora, the latter being a species for
which very low averages had been obtained elsewhere.
In the experiment carried out by Dr. Allen (p. 556), in which some
Calanus were kept alive for not less than about 50 days, and in which
two of the nauplii reached the adult stage, the flask used was kept standing
in the water of one of the tanks. In the case of the 2 Calanus that
were raised by Mr. Fuchs in an Echinopluteus culture, the jar containing
these was not submerged, but was kept standing on one of the slate
slabs under the tanks in the same room. Here these two specimens lived
for 57 days, and subsequently in Position A for another 24 days, making
a total period of 81 days. It is not known how far this result may
have been exceptional, like such examples as that in which a specimen
lived for 84 days in a 1-litre flask in Position A, but probably, under such
conditions, the temperature changes in the water of a jar of 2000 c.c.
would at most times be slight and gradual, and not such as seriously to
affect the animals.
For the 5 experiments with Calanus in vessels submerged in the tanks
the average, 35 days, 1s very incomplete, three of the experiments
being uncompleted. For the 4 experiments in vessels submerged in
the artificially heated bath, the low mortality at the time of their
interruption suggested an average not lower than was indicated in the
others, which at the close of the observations stood at rather more
than double the average (17 days) obtained for the 11 experiments with
this species in Position A.
As a series of preliminary experiments, the results with Pseudocalanus
may, on the whole, be regarded as fairly satisfactory, the small propor-
tion of naupli which were brought through to the adult form being
probably due to minor imperfections only in the conditions, possibly
in the food-supply which it should not be difficult to adjust.
The results of the experiments in Position C are not as conclusive
as might be wished, but their difference as a whole and in detail from
the others is so marked as to leave little doubt that the preservation of
an even temperature is of the first importance in experiments with
pelagic Copepoda, and probably indispensable to success with the
majority of pelagic plankton species.
On Diatom Growth in the Experiments.
In nearly all the experiments in Position C with Calanus finmarchicus
considerable difficulty was encountered in controlling the growth of the
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 571
food-supply (Nitzschia). Notes as to exact dates are incomplete, but the
rapidity of growth seems to have become especially apparent during the
second week, the Nitzschia then becoming so thick as soon afterwards
to necessitate the pouring off and renewal of the water. This was very
pronounced in the flasks submerged in the bath heated to about 18°.
Under the latter conditions, a flask containing only Nitzschia was re-
corded on the 12th day merely as “ growing well,” and another which
was taken over for use in an experiment on the 15th day without com-
ment was presumably in the same condition. In all of 4 flasks, how-
ever, which contained Calanus at this time—3 specimens in each—
the growth became very thick on the 11th or 12th day, and soon after-
wards so dense that it was very difficult to discern the specimens. In
the same bath with these flasks was the one containing 5 Acartia,
in which the specimens did well and produced several naupli, yet in
this case the growth was on the 40th day so slight that the Nitzschia was
then renewed. Similarly, in all the experiments with Pseudocalanus (4
with Nitzschia) no pronounced growth of the Diatom occurred during
the long period for which this species was kept.
While this overgrowth of food in experiments with Calanus was a
serious hindrance and probably interfered considerably with the
preservation of healthy conditions, the fact has a greater importance
in its bearig on Diatom growth. Further investigations are needed
before any very definite conclusions can be drawn from these limited
data, but the facts suggest the presence of a strong fertilising
action directly or indirectly traceable to the excretory products of
Calanus finmarchicus, which, though probably occurring also in other
species, seems not to occur in Pseudocalanus, or, judging from one
experiment, in Acartia.
The water used in all these experiments was “ outside ” water, some-
times sterilised, always with the addition of one-third Miquel-Allen
solution, that is to say, in the proportions of 2 ¢.c. of Solution A and 1 c.c.
of Solution B to 3 litres of sea-water, the water being then filtered through
a Berkefeld filter. How far the action arises independently of Miquel
is not yet clear. In two later experiments, each with 5 specimens, in 2
litres of unfiltered sterilised “ outside ’
growth was obtained. In consequence of this, it was decided to suspend
>
water only, a similar intense
the use of Miquel, and using only filtered unsterilised “ outside” water,
to reduce the number of specimens. In experiments made under these
latter conditions, with 1 or 2 Calanus in 2 litres of water, the growth has
been more often slight or moderate, though sometimes so- strong,
572 L. R. CRAWSHAY.
as to necessitate partial screening from the light. The intense
growth obtained in one-third Miquel water occurred in experiments
either with 3 Calanus per litre, or with from 2 to 5 Calanus per 2 litres.
During the transition, which was a gradual one, from one-fourth Miquel
to pure “ outside ” water, a thick growth was still obtained in an experi-
ment with 1 Calanus in 2 litres, when it was estimated that a trace only
of Miquel remained in the water.
The exact bearing which these facts may have on the problems of
Diatom growth which are under investigation by Dr. Allen* will, it is
hoped, become more apparent as the experiments are continued. That
the action of the Calanus excreta is such as greatly to intensify the
growth in the presence of the Miquel salts, even when the latter are
used in much reduced proportions, there seems to be no doubt. Whether
it is quite an independent one is at present somewhat uncertain.
The Influence of some Bacteria on the Experiments, and their Destruction.
In order to ascertain the possible influence of some of the common
Bacteria as contributing to the unsuccessful results of the earlier ex-
periments, some special experiments were carried out in which Bacteria
were encouraged to grow in large numbers in the water. As a food
basis a stock solution of peptone, of 5 grams per litre in strength, was
prepared in diluted Berkefeld water, and this was used in very small
quantities.
In some peptone-agar cultures which Mr. Drew kindly made for
me, from some infected water, two forms of Bacteria were obtained: one
producing large spreading, roughly circular, white colonies, from 1 to
5 millimetres in diameter; the other forming small compact, often
almond-shaped, yellowish-white colonies, usually about half a millimetre
in greatest measurement.
Three 1-litre flasks of diluted Berkefeld water were infected with both
of these forms, peptone being added in the percentages of -O01, -002,
and -O1, severally. On the following day the water in all the flasks
was Clouded with Bacteria.
In the first of these experiments (-001°% solution) the cloudiness con-
tinued unchanged on the 58th day. On the 68th day, it had nearly dis-
appeared, and the peptone being then renewed in the same proportions,
the bacterial growth was restored, and continued on the 90th day subse-
quently.
* Cf. Journ. Mar. Biol. Assoc., N.S., Vol. VIIL, p. 421; Vol. X., p. 417.
+ The most recent experiments support the view that the action is an independent
one.—L. R. C.
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 573
In the second experiment (-002°% solution) the cloudiness still con-
tinued on the 68th day, and the peptone being then renewed, there was
no falling off in the Bacteria on the 90th day afterwards.
In the third experiment (-01°% solution) the cloudiness was un-
changed on the 47th day, and the water was then inoculated with 20 c.c.
of a culture of a Ciliate, Huplotes sp. On the 9th day subsequently the
water was found to be cleared of Bacteria, the Huplotes being
present in very large numbers, but owing to my temporary absence
in the interval it was not known at what period exactly the
water became cleared. This experiment is of interest as exemplifying
the destructive action of a Ciliate on a Bacteria culture of long
standing.
In all experiments in which Bacteria were grown on peptone, or on
the macerating remains of dead plankton, the same action occurred
on the part of Infusoria, either naturally present or introduced into the
water. Those purposely introduced were from mixed cultures only, in
which one or more species were especially prominent. Such a culture
was that of Huplotes, which was kept for a long period in a flask in Posi-
tion A. Another large species, apparently a Strombidium, was usually
obtained in large numbers in “ outside ” water in which Bacteria were
grown, but some difficulty was encountered in retaining this indefinitely
as an active culture and often, after a varying period of multiplication,
it was lost sight of or died, being then usually superseded by a culture
of smaller forms.
Experiments were made partly in sterilised, partly in unsterilised
water. Of those here to be considered, 12 were made in 1-litre flasks
in Position A, and 2 were made in 11-litre bell-jars in Position B. Pep-
tone was used in proportions varying from -001% to -0001%, usually
in the former percentage, the Bacteria growth being induced by it
in some cases once only, in others as many as six times in the same
experiment.
The period occupied by Infusoria in clearing the water varied some-
what in the different experiments, apparently also in proportion to the
streneth of the peptone. Not always exactly observed, the period
ranged in 15 exact records, from 3 to 8 days, the average being 6 days,
from the time when the peptone was added, the Bacteria usually as-
suming a very strong growth within 24 hours later.
In some experiments in which this cycle of events was repeated a
few times, a point was reached when the culture became “sick” and
stagnant, the Bacteria growth being feeble, and the Infusoria falling off.
574 L. R. CRAWSHAY.
But in most cases the same process was repeated as far as the experi-
ments were carried.
In experiments with sterilised water, the Infusorian mostly employed
for inoculation was of the form which was referred to Strombidium, in-
cluding probably two, if not three, distinct species. This Ciliate, though
often lost sight of and superseded by smaller forms, was retained in some
experiments for a long period. In one case it continued fairly numerous
as late as the 67th day, after having cleared the water of four successive
cultures of Bacteria which were grown on peptone introduced on the
Ist, 13th, 39th, and 49th days, severally.
Following the destruction of a strong Bacteria culture by Infusoria,
there arises commonly, if not invariably, a more or less heavy deposit
of flocculent white patches in the water. The nature of this deposit,
possibly the excretory product of the Infusoria, was not ascertamed.
In one experiment which had been five times impregnated with peptone
within a period of 29 days, a sixth impregnation of the water decanted
off to a clean flask on the 34th day did not produce any distinct Bacteria
erowth, or any recurrence of the Infusoria, the water remaining sickly in
appearance. But a similar addition of peptone to the original flask with
its deposit, which had been refilled with clean sterilised “ outside ”
water, produced a strong Bacteria growth, the Infusoria continuing
fairly numerous for some 3 weeks later. In the former case conditions
had apparently arisen in the water, such as to resist further Bacteria
growth, the Infusoria being consequently deprived of their food-supply.
These observations, though passing beyond the range of the subject
of this paper, seem to deserve notice, as emphasizing the intimate rela-
tionship existing. between Infusoria and Bacteria in the sea, and the
destructive action of the former on the latter im experiments. This
bactericidal action may be peculiar to certain species, or again may not
in these be an essential feature of their natural existence : Huplotes, for
example, which is rapidly destructive of Bacteria, and will apparently
thrive on them alone indefinitely, was at first found to be feeding largely
on the spores of Chlorodendron. One point seems certain, that in so far
as such Infusoria may occur in experiments, their presence is not in itself
to be regarded as nocuous, but rather, on the contrary, as an indication
of the presence of unhealthy conditions which they are directly engaged
in counteracting.
As regards the influence of these common forms of Bacteria on the
experiments with the zooplankton, specimens of Calanoida and other
species, more especially small or young forms, were kept alive on several
EXPERIMENTS IN THE KEEPING OF PLANKTON ANIMALS. 575
occasions In the presence of these cultures for a considerable period, in
one case through 4 successive growths of Bacteria, extending over
some 6 weeks, the maximum life recorded—strangely, in this last-
mentioned experiment—being 48 days. Some notes concerning a few of
these experiments are appended :—
1-litre Flasks.
(No. 141.) In sterilised “ outside”? water, impregnated once with
peptone, on the Ist day, and cleared of Bacteria on the 9th day by
Euplotes.
Of about 6 Calanoids which were introduced on the 13th day, 3
(Acartia) were alive and active 34 days later. The maximum life period
was not recorded.
(No. 140.) In sterilised “ outside ” water, similarly impregnated once
with peptone, and cleared of Bacteria on the 8th day by a mixed culture
of Infusoria.
Of about 12 Calanoids introduced on the 14th day, about 6 were alive
after 7 days, 2 after 10 days, 1 after 20 days. The last was not alive on
the 31st day.
(No. 122.) In unsterilised “ outside ” water, impregnated twice with
peptone, on the Ist and 21st days, and cleared by contained Infusoria
on the 5th and sometime prior to the 30th day, respectively.
Of the Calanoids contained in the water at the outset, 2 or 3 adult
Temora were alive on the 30th day, and 1 on the 33rd day.
The water was aerated for a time on the 21st and 23rd days.
(No. 121.) In unsterilised “ outside ” water, impregnated four times
with peptone, on the Ist, 28th, 33rd, and 38th days, severally, and
cleared by contained Infusoria about 5 days later in each case.
Of several small forms in the contained zooplankton, 1 Balanus
nauplius was recorded alive as late as the 21st day; a few Calanoids
were alive on the 28th day ; and 2 Calanoids were alive on the 48th day.
The water was decanted off into a clean flask on the 8th day.
11-litre Bell-jars.
(No. 145.) In unsterilised “ outside” water, impregnated with
peptone on the Ist day only, and cleared by the contained Infusoria on
the 7th day.
20 or 30 small Calanoids were alive on the 10th day, about 4 on the
29th day. None were observed on the 42nd day.
(No. 144.) In unsterilised “outside” water, impregnated with
576 L. R. CRAWSHAY.
peptone on the Ist day, and again in smaller quantities on 5 days succes-
sively, from the 8th to the 12th day.
5 small Calanoids were observed alive on the 42nd day.
In both of these last-mentioned experiments the water became ex-
tremely foul on the 3rd day especially. In the second it was siphoned off
and back into the bell-jar on that day, for aeration. In the first, it was
not disturbed.
In these extreme cases, in which the Bacteria were grown, sometimes
repeatedly, in enormous numbers, the specimens were directly exposed
to the chemical changes produced in the water, apart from the intervals
when it was cleared, for about 4 or 5 days or longer as often as the Bac-
teria growth was renewed. In No. 121, for example, at least 2 Calanoids
survived, after nearly 7 weeks, an aggregate period of intense Bacteria
growth amounting to about 16 days. And in most cases the water
was not aerated or disturbed. From those results and from others
obtained in similar experiments, it seems evident that the influence of
common Bacteria of this character, occurring in comparatively small
numbers in the ordinary experiments, must be so slight as to be almost
negligible ; while the occurrence of Infusoria in the water can only be
regarded as counteractive to them, and probably as beneficial in the
presence of any unhealthy conditions that arise.
In all of these experiments no food was given other than was already
present in those in which the water was unsterilised. Apparently the
specimens were feeding on the Infusoria, and judging from the appear-
ance of the excreta this seemed to be the case.
So far as they have been observed, the Bacteria which can be of
serious harm to Copepoda in such experiments seem to be of infrequent
occurrence in the water employed. Two forms only have been definitely
recorded, to both of which allusion has already been made: the one
forming irregular white slimy strands through the water (p. 566) ;
the other giving a carmine-coloured tinge to objects attacked or
invested (p. 565). Each of these has been twice observed, and both
have proved in each case quickly fatal to all specimens that were con-
tained in the infected vessel, though an endeavour to cultivate the
second form has twice failed.
rte!
Twin Gastrule and Bipinnarize of Luidia sarsi, Duben,
and Koren.
By
James F. Gemmill, M.A., M.D., D.Sc.
With Figures Pls. I-III (Figs. 1-21).
Harty in June of this year (1914) I received from the Plymouth Marine
Laboratory through the kindness of Dr. E. J. Allen, F.R.s., several
Thermos flasks containing quantities of a culture of Luidia in the early
blastula stage. This culture was made for me by Mr. James Gray, King’s
College, Cambridge, to whom, and to Dr. Allen, I desire herewith to
express my indebtedness. The larve were little the worse of the journey
to Glasgow, but it seemed to me that they showed even greater irregu-
larities of form than might have been expected from Mortensen’s (13)
description of blastula formation in our species. However, in the end,
abundance of perfectly typical young bipinnarize* were secured from the
contents of the various flasks. The abnormal larve became gradually
fewer through death, and those which survived could be isolated without
much trouble, since they exhibited less capacity for keeping near the
surface of the water than their healthier brethren. A great many of the
early malformations were of the nature of double or twin formation,
and it soon became evident that the teratological type in question,
namely, double monstrosity, was about to receive a more varied expres-
sion, and to attain a more advanced stage in development, than it had
ever before been my good fortune to find in any starfish culture.
In the accompanying illustrations two series of abnormal larve are
figured, one at the gastrula stage (Figs. 1-11), and the other at that of
the early bipinnaria (13-21). As a description is appended to each
figure, only questions of general interest need be dealt with here.
Classification. In the systematic teratology of vertebrates, Double
* Two points in normal development may be noted here. (1) There does not appear to
be an auricularia stage in the formation of the bipinnaria, the preoral and postoral bands
being separated from one another antero-dorsally by a distinct interval at the time when
they are first recognisably differentiated in this field (see 7, p. 232). Indeed, the rela-
tively great width of the interval in question would by itself enable us to distinguish the
larva of Luidia from those of Asterias rubens, A. glacialis, and Porania pulvillus during
the first fortnight of bipinnarial life. (2) The small structure arising posteriorly from
endoderm and interpreted by me as a rudimentary posterior enterocoelic growth in Asterias
rubens, A. glacialis, aud Porania pulvillus does not appear to be formed in Luidia (see 7,
p. 233). ‘
578 JAMES F. GEMMILL.
Monstrosities are conveniently divided up into Anadidymi, Katadidymi,
Anakatadidymi, Mesodidymi (5; 14; 6, p. 3). To these a small group
falls to be added containing the few recorded examples of simple longi-
tudinal or parallel union (6, pp. 4, 29), which I venture to suggest may
suitably be termed Paradidymi. The Anadidymi are, of course, forms
with the anterior end more or less double, and the posterior end single ; in
the Katadidymi these conditions are reversed. The Anakatadidymi
show anterior and posterior doubling, but are single in their middle
regions, while the converse relations are characteristic of the Mesodidymi.
In the Paradidymi doubling occurs in an equal or sub-equal degree
throughout the whole of the longitudinal axis of the twins.
In fishes and other vertebrates, the notochord, the vertebral column,
the central nervous system and the alimentary canal, serve as our prin-
cipal guides in judging to which group a particular double monster should
be assigned. In double bipinnariz, on the other hand, we have to
depend entirely on the alimentary canal, inasmuch as the only other
easily recognisable longitudinal structure, namely, the posterior ciliated
band, owing to its superficial position, im most cases shows a greatly
lessened amount of doubling through the working of “ regulation ”
processes. Nevertheless, if the alimentary canal be taken as a guide, it
is remarkable how readily the various types of duplex bipinnarie fall
into the same kinds of groups as double-monster fishes. Thus Figs. 13
and 14 illustrate longitudinal or parallel union and are therefore Para-
didymi; Figs. 16 and 17 belong to the Anadidymi; Figs. 18 and 19 to
the Katadidymi; Fig. 20 is Anakatadidymous, and Fig. 21 Mesodidy-
mous in type. Probably, further search among the abnormal bipinnariz
would have revealed a still fuller and more representative series. There
remains to make mention of Fig. 15, which illustrates what may be
called tangential union, and would no doubt have included the bipin-
naria from the larva shown in Fig. 7 had survival been allowed. The
twin embryonic axes, as represented here by the alimentary canals,
are independent of, and widely divergent from, one another, but there
is superficial union of the lateral or frontal body-walls. Among monster
fishes we have no exact counterpart of this type, since, owing to the
manner in which the twin embryonic axes develop, practically the only
alternative to axial union is an Anakatadidymus effected through the
intermediary of the yolk-sac. However, in the amniotic vertebrates,
and particularly in the mammals, numerous instances occur in which,
without axial union being present, the twin organisms are united to
one another by paraxial or superficial structures.
TWIN GASTRULZ AND BIPINNARI®, D8)
The twin bipinnarie of Luidia are not directly comparable with
the double Echinus-rudiments noted by Metschnikoff (11) and
described in detail by MacBride (10), since the latter appear late
in development, and their formation is a consequence of the abnormal
persistence and differentiation of one particular organ, viz. a right
hydrocoele. The same thing is true of the changes characteristic of
double hydrocoele in the developing Asterias larva (7, p. 275). As
regards structure, suggestive analogies can be drawn between our
bipinnariz and the abnormal medusz described by Allmann (1) and
Browne (2). In normal embryology perhaps the most interesting
parallel is to be found in the development of the Annelid Lumbricus
trapezoides Dugés, in which a double gastrula, giving rise to two complete
earthworms, is produced by fission of the segmenting cell-mass (9). The
converse process, namely, fusion of two ova, has been shown to be
possible before (16 Ascaris) and after (16 Ascaris, 3 Spherechinus)
fertilisation, and also during the blastula stage (12 Spherechinus). In
general, such fusion tends to produce double monstrosities resembling
our bipinnarie, but sometimes a perfectly single organism of larger than
normal size is the result (16 ; 3).
Causation. HE. Haeckel (8, 1869) discovered that the segmented egg of
a Siphonophore (Crystallodes), if artificially divided, could give rise to
several partial embryos, and E. B. Wilson (15, 1893) found that during
the early stages of segmentation in Amphioxus each of the component
cells, if separated from the rest, could develop into a perfect gastrula,
while imperfectly double gastrule occurred abundantly in cultures
which had been subjected to shaking during the two-celled stage. A
series of such gastrule is shown in 15, Pl. XXXIV, Figs. 66-73, while in
Pl. XXXVII, some of the partially double stages which led up to them
(four-celled, eight-celled, blastulz) are also illustrated. As is well known,
similar or allied phenomena have been demonstrated to occur in the
development of many other ova, and there is now an extensive body of
literature dealing with experiments on the subject. Without going into
details for other groups, we may note that the ova of Asteroids were
early found to react to experiment in much the same way as those of
Amphioxus, and, what is more remarkable, it was ascertained by Driesch
(3) that as late as the blastula stage either half of a developing ovum
(Asterias glacialis, Astropecten) bisected transversely or longitudinally
could give rise to a bipinnaria. Thus in Asteroids it appears that single
cells in the earliest stages or cell masses at a later stage can, if isolated,
produce whole larve. On the other hand, if the cells or cell masses in
580 JAMES F. GEMMILL.
question are incompletely separated from one another, partial doubling.
or twin formation may result.
Usually in starfish ova, doubling of this kind is associated with dis-
turbances so profound that differentiation ceases in the gastrula stage.
In my own experience great numbers of partially double blastule have
appeared in different cultures of Asterias rubens, A. glacialis, and Porania
pulvillus, but none of these was observed to reach even the early bipin-
narial stages, and so far as I know such stages have not been figured or
described. Possibly the ova of Luidia possess unusually great potenti-
alities of duplex development, but we may, perhaps, conjecture that the
long-continued shaking which the cultures would suffer during their
journey (the Thermos flasks were left only three-quarters full for reasons
connected with aeration) effected a physiological separation of masses of
cells during the formation of the blastula, and at the same time diminished
their vitality less than do the more abrupt experimental methods
commonly employed in laboratory work.
Mode of Formation. Among Fishes the first noticeable feature in the
genesis of double monstrosities is that two centres of gastrulation arise
on the margin of the blastoderm. Next, the resulting embryonic axes
are either brought together so as to unite posteriorly, producing the
anadidymous type, or else remaining separate they give rise to anakata-
didymous union of the embryos by means of the yolk-sac. The kata-
didymous condition is extremely rare, and, indeed, probably never
occurs in perfect form. In the birds and mammals the larger proportion
of double monsters arises in connection with two centres of embryo
formation, but Katadidymus is not uncommon, being caused in most
cases by fission of the posterior end of a developing embryonic axis.
In fishes, birds, and mammals, since growth of the axis takes place
almost entirely from before backwards, true anterior fission either
does not occur or is extremely limited in extent. On the whole,
we see that throughout the vertebrates the important feature in the
production of double monstrosities is the presence of two foci of embryo
formation, and that in the simplest group, the fishes, these foci are, to
begin with, centres of gastrulation. As regards the Asteroids, a glance at
the series of illustrations to this paper will show that here also the
formation of two centres of gastrulation precedes _ bipinnarial
twinning. Two more or less separate archentera are produced, and
various other structures are partially or completely doubled. In the
end the two archentera may remain separate from one another (Figs. 1-4,
gastrule ; Figs. 13-15, bipinnarie), but if the foci of gastrulation are
TWIN GASTRULZ AND BIPINNARLE. 581
very close together, the infolding process may amalgamate them, giving
rise to an archenteron bifid in front and single behind (Fig. 5, gastrula ;
Fig. 16, bipinnaria). Again, in the case of a markedly bi-lobed blastula
an originally single invagination may, during inward growth, divide
into two branches (Fig. 6, gastrula; Fig. 17, bipinnaria), but we must
often leave the question open whether there has been anterior fission or
posterior fusion of archentera (Figs. 7, 8, gastrule). It is evident,
further, that anterior fusion of the archentera can take place (Figs 9-11,
gastrule ; Fig. 19, bipinnaria). In Fig. 20 fusion of the expanded
stomachal regions of the archentera is exhibited by a specimen with
“ back-to-back ” union. Fig. 18, on the other hand, illustrates a case of
** face-to-face ”
archentera share a common buccal cavity. In Fig. 21 (Mesodidymus)
the buccal cavity and rectum are single, while the cesophagus and
stomach are doubled and there is a composite enterocoelic cavity between
union in which the derivatives of two entirely separate
them. Fig. 7 shows triplicity in a modified form—the only instance of
triplicity observed.
An examination of the various abnormal bipinnarie figured will show
that each archenteron tends to produce a pair of enterocoeles. In most
cases all four persist (Figs. 13-15, 17, 18, 20). Sometimes two from
different pairs (right of left pair and left of right pair) are united together
(Figs. 19, 21). More rarely these two have either never been formed or
have disappeared at a very early stage (Fig. 16).
As regards the ciliated bands we note that their preoral and
postoral portions never become mixed—that is to say, the preoral
portion of one “twin” always unites with the preoral of the other,
and the postoral with the postoral. The general arrangement of
these bands, and of the larval fields they enclose, makes it patent that
quite remarkable powers of developmental “regulation” or “ making
the best of things ” must in many cases have been at work.
SUMMARY.
The various types of twin Luidia larve may be classified according
to the same system as Double Monstrosities among vertebrates, the
alimentary canal of the larve being taken as their representative axial
structure.
The causation depends on early partial separation of cells or of cell
masses, accompanied by a minimal interference with the vitality of the
whole.
582 JAMES F. GEMMILL.
Doubling (partial or complete) of the gastrula invagination is the
great step on which the differentiation of twin bipmnarie depends.
This differentiation shows very markedly the working of “ regu-
lation” processes in the course of which, when union of structures
occurs, the union is always between structures of homologous origin.
Thus preoral and postoral bands, enterocoeles, and particular regions
of the alimentary canal, unite each with its own counterpart.
REFERENCES.
1, Allmann, G. W. A Monograph of the Gymnoblastic or Tubularian
Hydroids. Part I, pp. 202-3, Fig. 76.
2. Browne, E. T. A Report on Meduse found in the Firth of Clyde.
Proc. Roy. Soc. Edinb., Vol. 25, Pt. IX, p. 753.
3. Driesch, H. Studien tiber Regulationsvermégen. IV. Die Verschmel-
zung der Individualitit bei Echinidenkeimen. Arch. f. Entw. M.,
Vol. 10, pp. 411-34.
4. Do., do., Altes u. Neues zur Entwickelungsphysiologie des
jungen Asteridenkeimes. Arch. f. Entw. Mech., Vol. 20, pp.
1-20.
. Forster. Missbildungen des Menschen, Jena, 1861, pp. 22,
29, 34.
6. Gemmill, J. F. The Teratology of Fishes, Glasgow, 1912.
7. Do., do., The Development and Certain Points in the Adult Structure
of the Starfish Asterias rubens. Phil. Trans. Roy. Soc.
London, 1914, B., pp. 213-94.
8. Haeckel, E. Zur Entwickelungsgeschichte der Siphonophoren.
Utrecht, 1869, pp. 73-9.
9. Kleinenberg, N. The Development of the Earthworm Lumbricus
trapezoides, Dugés. Quart. Journ. Micr. Sci., Vol. 19, 1879,
pp. 206-44.
10. MacBride, E. W. Two Abnormal Plutei of Echinus. London,
Q.J.M.S., Vol. 57, pp. 235-50.
11. Metschnikoff, E. Embryologische Mittheilungen tiber Echinodermen.
III. Zur Kenntniss der Wassergefissanlage bei Asteriden u.
Kchinoiden. Zool. Anz., Vol. 7, 1884, pp. 62-5.
12. Morgan, T. H. The Formation of one Embryo from two Blastule.
Arch. f. Entw. M., Vol. 2, pp. 65-71.
13. Mortensen, Th. On the Development of some British Echinoderms.
Journ. Mar. Biol. Ass: U.K., Vol. 10, No. 1, pp. 1-18, 1913.
Or
TWIN GASTRULA AND BIPINNARIZE. 583°
14. llacher, J. Terata mesodidyma von Salmo salvelinus. Wiener
Sitzber. Ak. Wiss. Naturw., Vol. 68, 1873, pp. 299-324.
15. Wilson, E. B. Amphioxus and the Mosaic Theory of Development.
Journal of Morphology, Vol. 8, 1893, pp. 579-615.
16. Zur Strassen, O. Ueber die Riesenbildung bei Ascariseiern. Arch.
f. Entw. M., Vol. 7, 1898, pp. 642-76.
584 JAMES F. GEMMILL.
DESCRIPTION OF FIGURES.
LETTERING EMPLOYED.
b.cav. Buccal cavity.
bl. Blastopore (anus of larva).
entc. Enterocoele.
entc’. Region of archenteron which produces the enterocoele.
ente.1. Left enterocoele.
entc.r. Right enterocoele.
m.o. Mouth opening.
oes. (Esophagus.
oes’. Region of archenteron which produces the cesophagus.
po.cil.bd. Postoral ciliated band.
pr.cil.bd. Preoral ciliated band.
rect. Rectum.
stom. Stomach.
stom’. Region of archenteron which gives rise to the stomach.
PLATE I.
Fies, 1-4.—Examples in which the archentera from two foci of gastrulation have
remained separate. In Fig. 1 the blastopores are near one another and the archentera
are parallel and equally developed. Compare the bipinnarial stage shown in Fig. 13.
In Fig. 2 the blastopores are again near one another, the archentera being unequal ;
compare the bipinnarial stage shown in Fig. 14, though in the latter the inequality
has manifested itself later and been less pronounced. In Fig. 3 the blastopores are a
considerable distance away from one another and the archentera are markedly unequal ;
compare also Fig. 7. In Fig. 4 the foci of gastrulation have appeared on opposite sides
of the larva.
Fics. 5-8.—Examples in which the blastopore being single, the archentera are bifid
anteriorly. In Fig. 5 the doubling only affects the anterior or enterocoelic-cesophageal
part of the archenteron; cf. the bipinnariz shown in Figs. 16 and 17. In Fig. 6 the
doubling reaches as far back as the commencement of the stomach ; ef. anterior portion
of the bipinnaria shown in Fig. 20. In Fig. 7 there is doubling to a like degree and in
addition there is a small, entirely independent archenteron with its own blastoporic
opening on one side; the larva thus exhibits a modified form of triplicity and is the only
triple monster obtained. For parallel instances in Fishes see 6, pp. 33, 35. In Fig. 8
the doubling extends as far back as the stomachal region; cf. posterior half of the
bipinnaria shown in Fig. 20.
Fries. 9-11.—Examples in which there are two separate blastopores, but the archen-
tera are united in front to a greater or less degree. In Fig. 9 the archentera are equal
and fused only at their extreme anterior ends; cf. the bipinnaria shown in Fig. 19.
In Fig. 10 there is the same condition, but the archentera are unequal. In Fig. 11 the union
reaches back to the stomachal region.
GEMMILL. TWIN GASTRULA PLATE I.
AND BIPINNARLEH OF LUIDIA.
Fic. 10. Fie. 11.
[ 585 ]
NEW SERIES.—VOL, X. NO, 4. MAY, 1915. Zaz
586 JAMES F, GEMMILI.
PLATE II.
(For lettering see p. 584.)
Fie. 12.—Normal bipinnaria of Luidia of same age as the twin bipinnarie described.
It will be noted that the preoral and postoral ciliated bands are completely developed
and that in the alimentary canal, buccal cavity, cesophagus, stomach, and rectum can
all be made out. There is a pair of enterocoeles, the left one being provided with a
hydropore. .
Fies. 13-21.—A series of double monster bipinnariz about six days old, showing
different kinds and degrees of duplicity. Here we must pay attention to a number of
details, e.g. the preoral and postoral bands and the surface areas which they mark out,
also the mouth and buccal cavity, the cesophagus, stomach, and rectum, the right and left
enterocoelic cavities and the hydropore and hydroporic canal. In general the doubling
is greater internally than externally, the enterocoeles and various parts of the food-canal
being sometimes in two sets without a corresponding degree of division being exhibited
on the surface of the body.
Fre. 13 is an example of parallel lateral union, as seen from the dorsal aspect. The
whole of the food-canal is doubled, the mouth and anus in both cases looking in the
same direction. Each food-canal has its own pair of enterocoeles, the left one in both
instances developing a hydropore and hydroporic canal. The whole bipinnaria is broader
than normal; there is a single preoral ciliated band enclosing the widened frontal field ;
the postoral ciliated band is also single, but shows a deep backwardly directed sinus on
the ventral side marking off the twin anal fields from one another.
In Fic. 14 one set of structures is much better developed than its neighbour, the
latter not showing mouth or anus, though provided with cesophagus, stomach, intestine,
and a pair of enterocoeles. Only one of the preoral ciliated bands is properly differen-
tiated, viz. that in connection with the frontal end of the better developed twin. The
view is from the ventral aspect.
Fic. 15.—A double monster bipinnaria in which one of the twins is smaller than, and
set at right angles to, the other. The smaller has no mouth and its frontal field is deficient
in size. The postoral ciliated bands run into one another.
GEMMILL. TWIN GASTRULA PLATE II
AND BIPINNARIA OF LUIDIA.
588 JAMES F. GEMMILL.
PLATE III.
(For lettering see p. 584.)
Fre. 16.—A bipinnaria in which there is doubling of the mouth, buccal cavity, and
first portion of cesophagus. The anterior end of the archenteron at the end of gastrulation
must have exhibited a very slight degree of doubling. The frontal extremity of the larva
is broadened, but in other respects the bipinnaria looks normal; cf. Fig. 5.
Fic. 17.—A bipinnaria with anterior doubling and posterior union. The two frontal
fields and buccal cavities face one another and lead into a single cesophagus which is
continued backwards into a single stomach, intestine, and rectum, the anus being in the
middle of the posterior surface. There are two pairs of enterocoeles, the left enterocoele
of the right twin and the right enterocoele of the left twin being shown in the drawing,
and the first-named has a hydroporic opening. The two preoral ciliated bands are
distinct from one another, but the postoral bands are continuous on opposite sides. The
circumoral food-collecting areas are also united.
Fie. 18—A double monster bipinnaria showing symmetrical ventral union of the
twin components, the fusion being somewhat greater at the anterior than at the posterior
end of the composite larva. There are two frontal areas bounded by preoral ciliated
bands on opposite sides of the bipinnaria, but each frontal area and ciliated band is to be
looked upon as composite, that is, derived in part from one and in part from the other of
the twin components. The buccal cavity is single, but also composite, and it communi-
cates with the surface by two mouth openings on opposite sides of the larva. The two
postoral ciliated bands are ununited though they approach one another posteriorly.
(Esophagus, stomach, etc. are separate and there are two pairs of enterocoelic pouches.
The circumoral food-collecting areas merge into one another.
Fic. 19.—A bipinnaria showing posterior doubling of the principal internal structures.
The view is from the dorsal aspect. The preoral ciliated band, the buccal cavity, and the
first part of the cesophagus are single, while the rest of the cesophagus, the stomach, and
the rectum are doubled. Note as regards the enterocoeles that the left one of the right
twin and the right one of the left twin have fused together to form a single composite
sac provided with a hydropore. The circumoral fields run freely into one another on the
ventral aspect of the larva.
Fic. 20.—A double monster bipinnaria with the components united back-to-back by
their dorsal body-walls. Internally there is a composite stomach, but otherwise the
food-canals are separate. The rectum and anus of the twin to the left of the drawing
were lost. The two preoral and postoral bands and the two circumoral areas have
remained separate on either side, and there are two pairs of enterocoelic pouches. As
regards internal structure we may describe this specimen as anakatadidymous, that is,
showing duplicity both anteriorly and posteriorly.
Fie. 21.—A double monster bipinnaria in which although the buccal cavity and the
rectum are single, there is doubling of the intervening regions, namely, the cesophagus and
stomach. The view is from the dorsal aspect, and the duplex structures lie side by side,
and look in the same direction. Three enterocoelic sacs are present. The middle one
possesses a hydropore and has evidently arisen by the fusion of a right sac belonging to a
left twin with a left sac belonging to the right twin. Compare with Fig. 19. In other
respects the bipinnaria, though slightly broader than usual in its middle region, is super-
ficially almost normal. As far as internal structure is concerned we may describe this
bipinnaria as exhibiting the mesodidymous condition.
GEMMILL. TWIN GASTRULZ PLATE III.
AND BIPINNARL# OF LUIDIA.
[ 590 ]
A Method of Separating Sponge Spicules by Filtration.
By
L. R, Crawshay, M.A.
THE separation of sponge spicules by the method here described has
been employed by me from time to time, for some years past, with such
satisfactory results that it may be recommended with confidence as a
useful and time-saving metlfod of preparing these or other minute hard
structures for microscopic examination.
For the suggestion of gun cotton as a filtering medium I am indebted to
Mr. D. J. Matthews, the simple apparatus adopted for its use being as
follows :—
A piece of glass tubing, about half an inch in inside diameter and eight
inches in length, is drawn out at one end rather abruptly to an opening
of about one-eighth of an inch or less, and this tube is passed through
a cork which serves to support it while resting loosely in the neck of a
flask or other waste receptacle. A very small piece of gun cotton, first
teased out evenly, is then pressed lightly with a glass rod into the lower
drawn-out end of the tube. This plug should be of the smallest possible
bulk sufficient to ensure easy filtration, and need not be more than about
one-eighth of an inch in depth.
The spicules having first been cleaned in a test tube by boiling in
nitric acid or Eau de Javelle, and the test tube having been filled up
with distilled water in the ordinary manner, the contents are poured
into the tube and, the liquid passing through the filter, the tube is refilled
with distilled water and afterwards twice with 90% alcohol. The
filter carrying the spicules is then pressed backwards into the tube and
shaken out through the broad end into a small test tube in which the
filter is thoroughly dissolved by shaking it up in equal parts of pure
ether and absolute alcohol, the tube being fitted with a cork to prevent
evaporation of the ether. When the spicules have settled the liquid is
pipetted off and the test tube is refilled with ether and alcohol and shaken
up as before. After pipetting off for the second time the tube is then
filled with 90 °%%, alcohol, from which after being allowed to settle
again, the spicules may be removed for mounting on the slide. In this
way the eun cotton is removed in solution. If it is not, a deposit will be
left on the slide when the liquid is burnt off which will more often spoil
SEPARATING SPONGE SPICULES. 591
the preparation, and there is a danger too of the spicules being partly
fused by the high burning temperature of the gun cotton.
The method has the advantage of much saving of time over that of
allowing the spicules to settle naturally in a test tube through the process
of cleaning and dehydration, and ensures a degree of completeness which
is greater perhaps than either this or the centrifuge method. When a
very small fragment only of a sponge is available, or where spicules are
of very small size or scarce in the specimen, it is especially serviceable
as retaining the whole of the spicules within a narrow compass, thus
obviating loss of material. Filtration may be accelerated by means of a
pressure pump if necessary, though it is better as far as possible to avoid
this owing to any additional pressure tending to pack the spicules too
closely on the filter or to break them. If through the filter being too
lightly adjusted too rapid filtration should occur, any spicules that may
have passed through can of course be recovered by refiltering the waste
hquid, and in view of this it is best to observe always the same
precaution in regard to cleanness for the flask as for any tubes or pipettes
that are used. Any of the latter that have been used in contact with the
dissolved gun cotton should be washed in the first instance in ether
and alcohol to ensure thorough cleaning and the removal of spicules
clinging to traces of the residue.
Though the method has been employed almost solely for the separa-
tion of sponge spicules, there seems no reason why it should not be found
of equal service in the treatment of Diatom tests, the shields of Coccoli-
thophoride, or any other minute structures which are uninjured by
ether or alcohol.
[ 592 ]
Polycheta of Plymouth and the South Devon Goat
including a list of the Archiannelida.
By
E. J. Allen, D.Sc., F.R.S.,
Director of the Plymouth Laboratory.
INTRODUCTION.
Tue present list of Polychetes is a revision of the list published in 1904,
as part of the general list of the Plymouth Marine Invertebrate Fauna
(Journ. Mar. Bool. Assoc., vol. vii., 1904, p. 219). It is the result of work
carried on in the intervals of other researches, as opportunity offered,
and there are in all probability a good many gaps still to be filled.
To the Plymouth records I have added those obtained at Salcombe
(Journ. Mar. Bool. Assoc., vol. vi., 1900, p. 151) and at Exmouth (ditto,
vol. vi., 1902, p. 295), a few records from the Teignmouth estuary, and
Major Elwes’ records from Torquay (Journ. Mar. Biol. Assoc., vol. viii.,
1908, p. 197, and 1909, p. 347; vol. ix., 1910, p. 59), the latter dealing
only with Polychetes found on the shore. Mr. Crawshay’s records,
from the valuable series of dredgings 8.8.W. of the Eddystone to fifty
fathoms, have also been included (Journ. Mar. Biol. Assoc., vol. 1x.,
1912, p. 339).
Apart from the Archiannelids there are comparatively few species in
the list which I have not been able to examine myself. In all cases
where no initials appear at the end of a paragraph the responsibility for
the record is my own.
My thanks are due to Major Elwes for a number of mounted specimens
of the Torquay species, which have been of great help, especially with
the Sylhide.
As regards nomenclature, after the name of each species, one or more
references have been given to papers where a detailed description of the
species intended is given. Whilst endeavouring as far as possible to
make use of that name which will probably stand, elaborate discussions
of nomenclature and synonymy have been in general avoided. The
main object has been to make quite clear which form is intended. Con-
siderable changes in the names used in the former list have been neces-
sary, since our knowledge of the British Polychete fauna has been
ereatly extended by the publication of several parts of Prof. McIntosh’s
POLYCH ETA OF PLYMOUTH. 593
Monograph, and of important papers on Irish Polychetes by Mr. R.
Southern. The character of the various dredging and trawling grounds
in the Plymouth neighbourhood is fully described in the general account
of the Plymouth Fauna (Journ. Mar. Biol. Assoc., vol. vui., 1904, p. 159),
where a chart of the area will also be found. Similar accounts of the
Saleombe and Exmouth areas will be found in the respective reports.
The following list of the Plymouth grounds, with depth and general
nature of the bottom, etc., may be useful for reference.
LIST OF PLYMOUTH COLLECTING GROUNDS.
Shore.
Rum Bay. This term is used to include the shore from Batten
Breakwater to Jennyclifi Bay. Shale rocks, with patches of gravel and
sand. Some stony ground.
Drake’s Island. Stony and rocky shore. Some patches of sand
and a zostera-bed.
Mount Edgcumbe. At the mouth of the Hamoaze. Very similar
to the rocky and stony ground on Drake’s Island.
Rocks below Laboratory. Rocks of hard Plymouth limestone,
with good rock-pools.
Dredging Grounds of Plymouth Sound.
Millbay Channel. 14-23 fms. Stones and mud. Free from growth
of seaweeds.
Asia Shoal. 5-7 fms. Stony ground with some growth of red sea-
weeds.
Queen’s Ground. 5-6 fms. The term is used to include the area
from Queen’s Ground Buoy to New Grounds Buoy and the ground
around the latter, all situated at the western entrance to Plymouth
Sound. The soil is shell gravel, with stones and shells. It is very free
from mud and there is some growth of red seaweeds.
Duke Rock. 4—5 fms. Near the eastern entrance to Plymouth
Sound. The bottom is rocky, with intervals of ground occupied by
stones and shells.
The Cattewater. The inner Plymouth harbour, where the bottom is
soft mud, which can be worked with-a shrimp trawl. The trawlers often
throw their refuse overboard here, and many of the outside species can
survive for a time.
594 E. J. ALLEN,
THE YEALM ESTUARY.
A sheltered estuary to the east of Plymouth, where a large body of
pure sea-water extends for a considerable distance from the mouth, and
the fauna is essentially marine.
OUTSIDE GROUNDS.
Shores.
Wembury Bay. A rocky shore, with intervals of sand. Some of the
reefs give considerable shelter from the breakers, especially at the
western side of the bay.
Reny Rocks. A reef of exposed, weed-covered rocks running from
the Shagstone to the mainland.
Whitsand Bay. An exposed shore which consists chiefly of fine,
shifting sand, with occasional rocky patches.
Dredging and Trawling Grounds.
Cawsand Bay. Depth 3-5 fms. An inshore, shallow, sheltered bay
with a bottom of fine sand.
Whitsand Bay. Depth4-8fms. A shallow sandy bay, more exposed
than Cawsand Bay.
Mewstone Ledge. Depth 10-15 fms. A ridge of soft red, con-
glomerate rock, free from growth of seaweed. The dredge breaks off
portions of the rock.
Mewstone Shell Gravel and ‘“Amphioxus” Ground. Depth
10-12 fms. Bottom of clean shell gravel.
Stoke Point Grounds. Depth 10-22 fms. Reefs of red conglomerate
alternating with patches of gravel and sand.
Rame-Eddystone Grounds. Depth 25-30 fms. Trawling ground
between Rame Head and the Eddystone. Bottom muddy gravel, with
clean sand in places.
Looe-Eddystone Grounds. Depth 25-30 fms. An extension west-
wards towards Looe of the Rame-Eddystone Grounds. Bottom similar
to that of the latter, but rougher.
Eddystone Grounds. Depth 28-35 fms. Bottom varied. They are
fully described in this Journal, vol. v., p. 365.
POLYCHETA OF PLYMOUTH. 595
EXPLANATION OF INITIALS.
The authorities for various records are indicated by their initials, a list of which
is given below. Initials have reference only to the paragraph in which they stand.
Where no initials are given at the end of any paragraph the records are by
E. J. Allen :—
A.J.8.—A. J. Smith, Assistant at the Laboratory since 1895.
c.8.—Creswell Shearer.
E.J.A.—E. J. Allen.
E.J.B.—E. J. Bles.
F.w.g.—F. W. Gamble.
J.?.c.—J. T. Cunningham.
R.A.T.—R, A. Todd.
s.P.—S. Pace.
T.v.H.—T. V. Hodgson.
w.B.B.—W. B. Benham.
w.a.— Walter Garstang.
ARCHIANNELIDA.
TURBANELLA HYALINA Max Schultze: Muller’s Archiv., 1853, p. 241.
PrymoutH. Found by Dr. C. Shearer on the glass of one of the
Laboratory tanks, July 26th, 1909. Dr. Shearer states :—“ This
form is apparently most rare, having never been described since
1853. Apparently an Archiannelid with parapodia of a primitive
kind. Usually placed in the Gastrotrichia.”
DINOPHILUS THNIATUS Harmer: Journ. Mar. Biol. Assoc. N.S. vol. 1,
Lg:
PriymoutH. In rock-pools in the Sound far above low water, in
March and April, not found in June (Harmer, loc. cit.). Found often
in immense numbers in pools high up on the limestone rocks below
the Laboratory and in front of West Hoe Terrace. Records of the
occurrence of the species below the Laboratory were kept by Mr.
A. J. Smith between 1906 and 1910. From these it appears that it
was abundant from November to April, but absent or very scarce
between May and October.
DINOPHILUS GYROCILIATUS Schmidt: Shearer, Quart. Journ. Mier. Sci.
vol. 57, 1912, p. 337.
PiymoutH. From sandy -dredgings from Cawsand Bay. Can
also be obtained in scrapings from the piles in Millbay Docks.
Lived well in small aquaria and became established in the Labor-
atory tanks (Shearer, loc. cit., p- 342).
Breeds all the year round in the Laboratory Tanks (c.s.).
PROTODRILUS FLAVOCAPITATUS Uljanin: Pierantoni, Protodrilus. Fauna
Flora Golf. Neapel. Mon. 31, 1908, p. 167.
Piymoutu. The first record of Protodrilus at Plymouth is by
596 Ee. AGEN
Bles (Jour. M.B.A., vol. 2, 1892, p. 343) who reared it from townettings
taken in September. He considers the species to be P. Leuckartii
Hatschek (Arbeit. Zool. Inst. Wien., vol. 3, 1880, p. 79).
Adults have since been found on the shore in numbers by Orton
(Nature, vol. 91, 1913, pp. 85 and 348) at eleven different points between
Salcombe and Looe, under stones and gravel near high-water mark,
where small fresh-water streams join the sea. Orton records this
species as P. flavocapitatus Uljanin.
CTENODRILUS PARDALIS Claparéde : Beobactungen iiber Anat. u. Entw.
wirbellos. Thiere a. d. K. von Normandie, 1863, p. 25.
PrymoutH. Found in the Laboratory tanks and also in pools at
high-tide level below the Laboratory by Dr. C. Shearer. Some
years it is very abundant in the tanks, in other years it is absent
(C.8.). '
NERILLA ANTENNATA Schmidt: Goodrich, Quart. Journ. Micr. Sci.
voll, Lol2 ont.
PrymoutH. First recorded by Miss F. Buchanan (Rep. Brit. Assoc.
1892, p. 358). It has since been found to occur frequently in the
Laboratory tanks, and also in scrapings from piles in the Catte-
water.
Breeds from February to June in the Laboratory Tanks (c.s.).
SaccocrrRgus sp.: Goodrich, Quart. Journ. Micr. Sci. vol. 44, 1901,
p. 413 ; and Prerantoni, Ann. Mus. Zool. Napoli, vol. 2, no. 18, 1907.
PrymoutH. Found by Orton in Cawsand Bay together with
Protodrilus, amongst stones and gravel just below high-water mark
where a small fresh-water stream joims the sea. He thinks the
species different from S. papillocercus Bobretzky (Nature, vol. 91, 1913,
p. 348).
PoLtyGorDIUS LAcTEUS Schneider: Hempelman, Zeitsch. wiss. Zool.
vol. 84, 1906, p. 527.
Piymoutu. Dredged in clean shell gravel off the Mewstone and
near the west end of the Breakwater. In clean shell gravel near the
Eddystone and off Bolt Head.
HisTRIOBDELLA HOMARI van Beneden: Foettinger, Archiv. Biologie, V.
1884, p. 435. Shearer, Quart. Journ. Micr. Sci. vol. 55, 1910, p. 287.
Prymouts. Usually found on the eggs of lobsters taken by
fishermen, but normally an inhabitant of the branchial chamber (C.s.).
Breeding during the summer months.
Breeding in September (C.s.).
POLYCHETA OF PLYMOUTH. 597-
POLYCH ATA.
SYLLID As.
EXOGONE GEMMIFERA Pagenstecher: McIntosh, Mon. Brit. Ann. I. 1,
1908, p. 151.
Prymouts. Common on the shore amongst the roots of Laminaria
and other weeds, in the Sound and on the coast outside. Frequent
in dredgings from the Sound. It also occurs in dredgings from
deeper water, e.g. 2 miles off Yealm Point in 15 fms. and off the
Eddystone in 30-35 fms.
Breeding: A number of specimens found amongst Ascidians
from the piles in Millbay Dock in June carried eggs and embryos
in different stages of development.
Toreuay. Not uncommon amongst sea-weeds from half-tide
mark downwards (Elwes, Journ. M.B.A., vol. 8, 1908, p. 197).
SPHEROSYLLIS HYSTRIX Claparéde: McIntosh, Mon. Brit. Ann. he
1908, p. 157.
PrymoutH. Frequent in dredgings from the Sound ; occasional
specimens amongst roots of weeds from the shore.
SPH#ROSYLLIS OVIGERA Langerhans: Wurmfauna v. Madeira, Zeitschr.
Wiss. Zool. XXXII. 1879, p. 567.
Piymoutu. In the Sound near New Grounds Buoy. Several
specimens have been taken.
The species seems to be quite distinct from S. hystrix as well as
from S. pirifera, Claparéde. The palps are very broad and the
median tentacle is in a line with or more generally in front of the
anterior eyes, as figured and described by Langerhans. The body
is always coated thickly with sand and mud, which enables the
specimens to be separated at once from the S. hystrix found in
the same material. The body is covered with papill.
SPH#ROSYLLIS ERINACEUS Claparéde, var.: de St. Joseph, Ann. Polych.
Dinard ; Ann. Sci. Nat. Zool. 1886, p. 207.
Prymoutu. Common amongst roots of Laminaria from Rum
Bay.
The specimens differ from the descriptions and figures of Claparéde
and de St. Joseph in having the two anal cirri large and much
swollen at the base.
Breeding: A specimen obtained in June had four large eggs on
each segment from Segt. 9 backwards. The eggs were carried on
the dorsal side of the segment. On the segments anterior to Segt. 9,
four round tubercles were present on each, in positions corre-
sponding to those occupied by the eggs.
598 E. J. ALLEN.
GRUBEA CLAVATA, Claparéde: Beobactungen, p. 41. Pl. XIII. Figs.
28-29. de St. Joseph, Ann. Sci. Nat. Zool. I. 1886, p. 200.
PiymoutTH. From Laminaria roots, Rum Bay shore.
Torquay. One example from Laminaria root, Oddicombe
Beach (Elwes, Journ. M.B.A., vol. 8, 1908, p. 197).
GRUBEA LIMBATA Claparéde: Ann. Chétop. Naples, p. 208. Vzaguweer -
Arch. Zool. Exp. II. 1884, p. 103.
PrymoutH. From Laminaria roots from the Breakwater and
Reny Rocks. Dredged near the east end of the Breakwater in
4 to 5 fms.
Four specimens have been obtained altogether, one in June
with long swimming bristles. The specimens agree in all respects
with the descriptions of Claparéde and Langerhans. The buccal
segment is hidden by a raised collar similar to that seen in Eusyllis.
GRUBEA PUSILLA Dujardin: Langerhans, Zeitschr. Wiss. Zool. XXXII.
1879, p. 565. de St. Joseph, Ann. Sci. Nat. Zool. 1. 1886, p. 203.
PrymoutH. Amongst the roots of Laminaria from Rum Bay.
Breeding: Two females with embryos on the parapodia were
seen in March.
PIONOSYLLIS LAMELLIGERA de St. Joseph: Ann. Sci. Nat. Zool. I.
1886, p. 163.
PrymoutH. In dredgings from Duke Rock, New Grounds,
between Knap and Panther Buoys, and Mewstone Ledge. Amongst
Laminaria roots from Reny Rocks.
Torquay. Very common in Laminaria roots (Elwes, Journ. M.B.A.
vol. 8, 1908, p. 198).
PIONOSYLLIS DIVARICATA Keferstein: McIntosh, Mon. Brit. Ann. II.
1, 1908, p. 164. de St. Joseph, Ann. Sci. Nat. Zool. I. 1886, p. 160
as P. longocirrata.
PiymoutH. One specimen from dredgings from New Grounds.
Torquay. Three or four specimens from Corbyn’s Head (Hlwes,
Journ. M.B.A., vol. 8, 1908, p. 198).
KUSYLLIS TUBIFEX (Gosse): McIntosh, Mon. Brit. Ann. II. 1, 1908,
p. 173. (Probably the same as #£. Blomstrandi, Malmgren as de-
scribed by de St. Joseph, Ann. Sci. Nat. Zool. I. 1886, p. 171.
Cf. Southern, Clare Island Survey, Pt. 47, Proceed. Roy. Inish Acad.
XXXI. 1914, p. 32.)
PiymoutH. Very common in the Sound from the shore and in
dredgings. Often met with in dredgings from outside, e.g. Mewstone
Ledge and Eddystone Grounds.
Breeding: Females with ova and swimming bristles recorded
in February and March.
Torquay. Fairly common amongst weeds covered with Polyzoa
and Sertularia (Zlwes, Journ. M.B.A., vol. 8, 1908, p. 198).
POLYCHATA OF PLYMOUTH. 599
Breeding: Females with ova, some with well developed swim-
ming bristles, in April.
EUSYLLIS MONILICORNIS Malmgren: de St. Joseph, Ann. Sci. Nat. Zool.
I. 1886, p. 169 (cf. Langerhans, Wurmfauna von Madeira, Zeits.
Wiss. Zool. XXXII. 1879, p. 551).
PiymoutH. Single specimens have been taken on a number of
occasions from dredgings in the Sound, at Duke Rock and Asia
Shoal. One from Mewstone Ledge.
The species is clearly distinguished from E. tubifex (Gosse) by its
more robust form, and by the character of the sete, the end pieces
of which are of two kinds in each typical foot, the one short and
stout, the other long and slender. The hinder part of the head
generally carries a conspicuous patch of dark brown or black pig-
ment.
KUSYLLIS LAMELLIGERA Marion and Bobretzky: Annélides du Golfe
de Marseille, Ann. Sci. Nat. 6° sér. II. p. 33. Pl. III. Fig. 9. de Sé.
Joseph, Ann. Sci. Nat. Zool. I. 1886, p. 169.
PiymoutH. Two or three specimens have been obtained from
dredgings from Mewstone Ledge and Eddystone Grounds.
Breeding: A female with nearly ripe eggs was taken in July.
A well defined species, which can easily be recognised by the
enlarged leaf-like shape of the first pair of ventral cirri. It is well
described by Marion and Bobretzky.
ODONTOSYLLIS CTENOSTOMA Claparéde: McIntosh, Mon. Brit. Ann. IT.
1, 1908, p. 182.
PiymoutH. Very abundant on the shores of the Sound and
frequent in dredgings from the Sound.
Breeding: A specimen in the swimming stage, with long sete,
was recorded in May.
Torquay. The most abundant of all the species of Syllids
(Elwes, Journ. M.B.A., vol. 8, 1908, p. 199).
ODONTOSYLLIS FULGURANS Audouin and Edwards: McIntosh, Mon.
Bee Ann, Le 1908, p. 1719:
PiymoutH. Dredged at Queen’s Ground (New Grounds), Mew-
stone Ledge, off Stoke Point and on Rame Eddystone Grounds.
Usually not more than one specimen on each occasion.
ODONTOSYLLIS GIBBA Claparéde: McIntosh, Mon. Brit. Ann. II. 1,
1908, p. 183.
PiymouTH. Common in dredgings from Asia Shoal, Duke Rock,
Queen’s Ground and Millbay Channel.
Torquay. Several examples were found at Corbyn’s Head
(Elwes, Journ. M.B.A., vol. 8, 1908, p. 199).
TRYPANOSYLLIS ZEBRA (Grube): McIntosh, Mon. Brit. Ann. II. 1,
1908, p. 169.
600 Bi) J. ALLEN:
PrymoutH. Frequent in dredgings from Millbay Channel and
Asia Shoal. Occasionally from other parts of the Sound. Yealm
dredging. On the shore at Wembury Bay in a mass of yellow
sponge.
Torquay. Fairly numerous among Laminaria roots from the
rocks between Babbacombe and Oddicombe beaches (Elwes, Journ.
M.B.A., vol. 8, 1908, p. 200).
TRYPANOSYLLIS CAELIACA Claparéde: McIntosh, Mon. Brit. Ann. II.
2, 1910, p. 240.
Torquay. Four or five specimens from Oddicombe Rocks (Elwes,
Journ. M.B.A., vol. 8, 1908, p. 201).
EURYSYLLIS PARADOXA (Claparéde): McIntosh, Mon. Brit. Ann. II. 2,
1910, p. 241.
PiymMouTH. Occasional specimens from Asia Shoal dredgings
and from dredgings on the rocky ground south of the Break-
water. One or two from Laminaria roots from the shore at Reny
Rocks.
Breeding : A specimen with hinder segments swollen with genital
products from Reny Rocks in July.
Toreuay. From Oddicombe, Corbyn’s Head and Livermead
(Elwes, Journ. M.B.A., vol. 8, 1908, p. 201).
SYLLIS (TYPOSYLLIS) ARMILLARIS (Miiller): McIntosh, Ann. Mag. Nat.
Hist. Ser. 8. vol. xi, 1913, p. 83. McIntosh, Mon. Brit. Ann. II. 1,
1908, p. 188; ditto II. 2, 1910, p. 238.
PrymoutH. Eddystone Grounds (Weldon, Journ. M.B.A., vol. 5,
1899, p. 481). A number of specimens from 20 to 50 miles 8.S.W.
of Eddystone in 42-49 fms. (L.R.c.), Frequent on all dredging grounds
in and around Plymouth Sound. Amongst Ascidians from Millbay
Dock. Occasional specimens from the shore.
The species was included in former lists (Journ. M.B.A., vol. 7, 1904,
p. 219) as Typosyllis alternosetosa, de St. Joseph.
Torquay. Fairly common. Recorded as Typosyllis alternosetosa
(Elwes, Journ. M.B.A., vol. 8, 1908, p. 199).
SYLLIS (TYPOSYLLIS) PROLIFERA Krohn: Langerhans, Zeit. wiss. Zool.
XXXII, 1879, p. 530. Claparéde, Glanures Zoot. parmi les Annél.
de Port-Vendres. 1864, p. 70 (530) as Syllis Armandi. McIntosh,
Mon. Brit. Ann. II. 1, 1908, p. 167 as Pronosyllis hyalina Grube
and possibly in part, p. 161 as Pionosyllis prolifera Krohn.
PiymoutH. Common everywhere amongst weeds, etc., on the
shore, as well as in dredgings from shallow water especially in
Plymouth Sound. :
Toreuay. One of the most numerous of the Torquay Syllids.
A very variable species (Elwes, Journ. M.B.A., vol. 8, 1908, p. 199).
There is some difficulty in deciding the correct nomenclature and
POLYCHZTA OF PLYMOUTH. 601
synonymy of the three forms of Syllis which have been described
by different authors under the names, Syllis prolifera Krohn,
S. variegata Grube and S. hyalina Grube. After examining a con-
siderable number of living specimens my own view is that two
distinct species have been referred to under these names, which
would most conveniently and probably according to the law of
priority most correctly bear the names S. prolifera Krohn and
S. variegata Grube. The name S. hyalina Grube has I think most
frequently been applied to examples of S. prolifera (and possibly
other species) which were not yet fully grown.* In S. prolifera
Krohn the pharynx is comparatively short and stout, the single dor-
sal tooth is large and is usually situated at the hinder end of the
first third of the pharynx. There is a considerable distance between
the point of the tooth and the anterior edge of the pharynx.
The proventriculus is comparatively short and stout, being
about the same length as the pharynx.
The end pieces of the bristles have very boldly bifid tips, the
bifid character becoming more and more marked in the posterior
seoments, where the end pieces also become much shorter.
In the last few parapodia there is in each a single straight simple
bristle dorsally, the tip of which is often with some difficulty seen
to be bifid, and ventrally a single curved simple bristle with a boldly
bifid tip exactly resembling the tip of the compound bristles.
The anterior segments contain a quantity of brown pigment on
the dorsal surface. This pigment is in many specimens distributed
fairly uniformly over the surface, but more generally it tends to
accumulate along the posterior border of the segment forming a
transverse brown bar. In other specimens again in addition to this
posterior bar there is an accumulation of the pigment in the centre
of the dorsal surface of the segment, a brown patch above each of
the dorsal cirri, and a bar along the anterior border of the segment.
The pattern thus formed tends to resemble that of S. variegata,
but this pattern is not often found in S. prolifera, in which the
uniform distribution of pigment on the dorsal surface with a pos-
terior brown bar is the more characteristic condition.
The dorsal cirri are moniliform. They are distinctly long, as
compared for example with S. armillaris or S. gracilis, and in well-
grown worms have from 25 to 30 or even 40 articulations. They
differ in length, being alternately long and short throughout the
greater part of the body.
The Pionosyllis hyalina Grube described by McIntosh (Mon.
Brit. Ann. II. 1, 1908, p. 166) is almost certainly this form in an
immature condition, with the cirri not yet fully grown and thus
having fewer articulations.
* It should be noted that the S. hyalina of Malaquin is the S. alternosetosa de St. Joseph,
recorded in the present list as 8. armillaris (Miiller) (Rech. sur les Syllidiens, 1893, p. 96).
NEW SERIES.—VOL. X. NO. 4. MAY, 1915. 2Q
602 E. J. ALLEN.
The corresponding characters of S. variegata are described below
under that species.
SYLLIS (TYPOSYLLIS) VARIEGATA Grube: Langerhans, Zeit. wiss. Zool.
XXXII, 1879, p. 532, Marenzeller, Sitzb. mathem.-naturw. Cl.
LXIX. Bd. I. 1874, p. 441. McIntosh, Mon. Brit. Ann. II. 1, 1908,
p. 161 as Pronosyllis prolifera (Krohn).
PrymoutH. Not uncommon in dredgings from Millbay Channel
and Asia Shoal. Off Yealm Head. One large specimen from the
shore at Wembury Bay amongst Laminaria roots.
South by west of Eddystone in 44-49 fms. (Crawshay, Journ. M.B.A.,
vol. 9, 1912, p. 340).
The distinction between S. variegata and S. prolifera will be seen
on comparing the following characters. In S. variegata Grube the
pharynx is long and slender, extending through as many as ten
segments when a fully grown worm is alive and crawling. The single
dorsal tooth is relatively smaller than in S. prolifera and lies close to
the anterior margin of the pharynx.
The proventriculus is long and relatively narrower than in S.
prolifera.
The end-pieces of the bristles are on the whole longer than those
of S. prolifera and are much less boldly bifid at the tip. The long
end-pieces are continued back to the posterior segments to a much
greater degree than in S. prolifera and the bifid character does not
to the same extent become more marked.
Simple bristles occur in the posterior parapodia as in the former
species. Their bifid character is not easy to make out, but some
of the bristles seem to show it under a high power of the micro-
scope.
The pigment is brown and the transverse figure of eight pattern
described by Grube and subsequent authors is very characteristic
on the anterior segments. This pattern is able to considerable
modification, one extreme form of which is described and figured
by McIntosh (p. 162, fig. 53). It will be seen that merely by thicken-
ing the different bars and dots figured by McIntosh until their ends
touch the characteristic variegata pattern is produced. The largest
specimen of S. variegata which I have examined resembles McIntosh’s
description in colour pattern as well as in all other respects.
The dorsal cirri are moniliform and long, in most cases longer
than in S. prolifera. In a large specimen the median tentacle con-
tained about 42 articulations, whilst the lateral contained 20. The
dorsal cirri along most of the length of the body are alternately long
and short ; in the specimen referred to there were 43 articulations in
the long cirri and 20 in the short ones. The short cirri are carried
by the worm horizontally, whilst the long ones rise vertically and
arch over the back, the ends being frequently coiled. The long and
short cirri are of nearly uniform diameter throughout, thus differing
from Syllis Krohnii Ehlers.
POLYCHZTA OF PLYMOUTH. 603
SYLLIS (TYPOSYLLIS) KROHNII Ehlers: McIntosh, Mon. Brit. Ann. Il. 1,
1908, p. 192.
Prymours. Amongst Corallina from Rum Bay, and from under
a stone at Wembury Bay.
Breeding : A specimen from Wembury Bay in March had a well-
developed stolon with four red eyes.
Torquay. Amongst Corallina from Corbyn’s Head (Elwes, Journ.
M.B.A., vol. 8, 1908, p. 200).
SYLLIS (EHLERSIA) corNUTA Rathke: McIntosh, Mon. Brit. Ann. IT. 1,
1908, p. 200.
PrymoutH. Eddystone Grounds (Weldon, Journ. M.B.A., vol. 5, 1899,
p. 481). Occasional specimens which I believe belong to this species
have been obtained from dredgings from Duke Rock, Queen’s
Ground and Asia Shoal, but the identification is not quite certain,
SYLLIs GRACILIS Grube: McIntosh, Mon. Brit. Ann. II. 1, 1908, p. 203,
PrymoutH. Dredgings from Millbay Channel, Asia Shoal and
Queen’s Ground. Single specimens frequently met with. Rum
Bay shore, from crevices of shale.
SYLLIS (HAPLOSYLLIS) SPONGICOLA Grube: McIntosh, Mon. Brit. Ann. II.
1, 1908, p. 197.
PrymoutH. Occasional specimens have been found in dredgings
from Plymouth Sound (Millbay Channel, Winter Shoal, Cawsand
Bay). A considerable number of specimens were obtained from
a mass of slimy sponge dredged on the Mewstone Ledge.
SaLcoMBE. In dredgings from the channel between Salstone
and Snape’s Point (Journ. M.B.A., vol. 6, 1900, p. 190).
Torquay. Fairly abundant (Zlwes, Journ. M.B.A., vol. 8, 1908, p. 199).
- AMBLYOSYLLIS LINEATA Grube: McIntosh, Mon. Brit. Ann. II. 1, 1908,
p- 225. de St. Joseph, Ann. Sci. Nat. Zool. I. 1886, p. 187 as Ptero-
syllis (Gattiola) spectabilis Johnston.
PiymoutH. Common in dredgings from Millbay Channel: less
numerous Queen’s Ground, Mallard and Asia Shoal (£.9.4., R.A.T.,
T.V.H.): sometimes in large numbers in sponges from Millbay
Ch. (w.G.). Occurs also amongst Laminaria roots from the shores.
of the Sound, in dredgings from outside the Breakwater, off Yealm
Head and occasionally on Eddystone Grounds.
SaLcomBE. Dredged in the channel west of Salstone (Journ.
M.B.A., vol. 6, 1900, p. 190).
Torquay. In weeds from rocks between Oddicombe and Babba-
combe (Elwes, Journ. M.B.A., vol. 8, 1908, p. 199).
It seems probable that Claparéde’s Pterosyllis formosa is the
species under consideration. Both McIntosh and de St. Joseph
appear to take this view though neither adopts Claparéde’s name,,
which has priority.
604 - EJ) ARLEN
AUTOLYTUS LONGIFERIENS de St. Joseph: Ann. Sci. Nat. Zool. vol. 1,
1886, p. 217. McIntosh, Mon. Brit. Ann. II. 2, 1910, p. 245. Southern,
Proceed. R. Irish Acad. XX XI]. 47, p. 39.
PiymoutH. Two specimens were dredged on rocky ground
immediately south of the Breakwater in May, one from Duke Rock
in June and one was found amongst roots of Laminaria from Rum
Bay in June.
The male (Polybostricus) and female (Sacconereis) forms of this
species were obtained in townets near the Eddystone in February.
From one Sacconereis kept in the Laboratory the young hatched
two weeks after the specimen was procured.
Torquay. Five or six specimens were obtained on the shore
(Elwes, Journ. M.B.A., vol. 8, 1908, p. 202).
AUTOLYTUS RUBROPUNCTATUS (Grube): Marion and Bobretzky, Ann.
Golfe Marseille, 1875, p. 44 as Autolytus (Procerea) ornatus. Southern,
Proceed. R. Irish Acad. XXXI. 47, 1914, p. 40.
PrymoutH. Frequent in dredgings from the Sound, Asia Shoal,
Queen’s Ground and Duke Rock. Frequent also on all the dredging
and trawling grounds between Plymouth and the Eddystone and
westwards to Looe.
Breeding: No specimens with stolons were found amongst a
large number examined between January and June. At the be-
ginning of July, one specimen was seen with a stolon just beginning
to form. The observations were interrupted after that month.
Southern has pointed out that the description given by McIntosh
(Mon. Brit. Ann. II. 1, p. 186) does not agree with that of other
observers. The Plymouth specimens have no ventral cirrus and
the sete have the typical bifid end-pieces of the genus Autolytus.
McIntosh’s coloured figure is stated to be from a Plymouth example.
Avutotytus pictus (Ehlers): McIntosh, Mon. Brit. Ann. II. 1, 1908,
Pagel.
PiymoutH. Frequently met with in dredgings from all grounds
in Plymouth Sound ; especially common amongst Aleyonidiwm and
sponges from Asia Shoal. Occasional specimens on all grounds
between Plymouth and the Eddystone, especially on rough ground.
Breeding: Three specimens with the Polybostricus head just com-
mencing to form were found in dredgings from Asia Shoal in April.
Torquay. Rather common on the shore (Elwes, Journ. M.B.A., vol. 8,
1908, p. 201).
AUTOLYTUS MACROPHTHALMA (Marenzeller): de St. Joseph, Ann. Sci.
Nat. Zool. I. 1886, p. 226. Southern, Proc. R. Inish Acad. XXXI.
47, 1914, p. 41.
PiymMoutH. Specimens have been obtained in dredgings from
Millbay Pit, Asia Shoal, New Grounds, Tinker Buoy, and 1 mile
off Rame Head.
POLYCHETA OF PLYMOUTH. 605
Toreuay. Two examples from the shore at Babbacombe (wes,
Journ. M.B.A., vol. 8, 1908, p. 201).
AUTOLYTUS EHBIENSIS de St. Joseph: McIntosh, Mon. Brit. Ann. LH.
2, 1910, p. 243. de St. Joseph, Ann. Sci. Nat. Zool. I. 1886, p. 228.
PrymoutH. From Laminaria roots and sea-weeds from the
shore at Rum Bay, and amongst Ascidians, ete., from Millbay Dock.
Dredged off Yealm Head and near the Eddystone.
Breeding: Specimens with chains of buds in January, in
February and in April.
Torquay. Found in great abundance on Fucus, which was
covered with Sertularia pumila, on the Breakwater at Babbacombe
(Elwes, Journ. M.B.A., vol. 8, 1908, p. 201).
AUTOLYTUS PUNCTATUS de St. Joseph: Ann. Sci. Nat. Zool. I. 1886,
p. 233.
Piymouru. Not uncommon on Queen’s Ground and on the
Rame-Eddystone and Looe-Eddystone trawling grounds.
Breeding: Specimens with stolons were taken from May to
July. The breeding season probably extends considerably beyond
these months.
This species has only been recorded from Dinard by de St. Joseph,
from Boulogne by Malaquin (Syllidiens, Lille, 1893, p. so), and from
the west of Ireland by Southern (Proceed. R. Irish Acad. XX XI. 47, 1914,
p. 42). It is easily recognised from de St. Joseph’s description.
Autotytus Epwarst de St. Joseph: Ann. Sci. Nat. Zool. I. 1886,
p. 235.
PrymoutH. This species is common in dredgings from Duke
Rock and the rocky ground immediately south of the Breakwater.
It appears to often live in tubes attached to the fronds and roots of
Laminaria.
Breeding: Specimens with stolons were found from March to
June and the breeding season probably extends beyond these
months.
The species, which is well defined, has only been recorded by
de St. Joseph from Dinard, by Malaquin (Syllidiens, Lille, 1893, p. 80)
from Boulogne, and by Southern (Proceed. R. Irish Acad. XXXI. 47, 1914,
p. 43) from the west of Ireland.
AUTOLYTUS PROLIFER (O. F. Miiller): de St. Joseph, Ann. Sci. Nat.
Zool. I. 1886, p. 238. Langerhans, Zeits. Wiss. Zool. XXXII. 1879,
p- 575.
Piymoutu. ‘Two specimens from Millbay Pit dredgings and one
from dredgings from the rocky ground south of the Breakwater.
Breeding: Specimen in May had one stolon. In July a female
had many eggs in the body segments.
The pharynx has ten large equal teeth, which according to Langer-
hans and de St. Joseph is characteristic of this species. The body
606 BK. 63, AEN:
is more robust than that of A. Edwarsi or A. punctatus and the
living worms were picked out as distinct from the other species
found here, on account of their form and movements, before the
pharynx was examined. I agree with Southern that many of the
records of this species in the literature are unreliable.
AUTOLYTUS LUGENS de St. Joseph: Ann. Sci. Nat. Zool. I. 1886,
p. 234.
PitymoutH. Three or four specimens in dredgings from Queen’s
Ground and Millbay Pit.
Breeding: In January and February the stolon was just begin-
ning to form ; in July a large stolon was well developed.
The specimens agreed with de St. Joseph’s description. The
massive black tentacles and dorsal cirri of the first segment were
very conspicuous. The anal cirri had the same form, and the
pharynx has 16 equal teeth. I have found no other record of the
species except that by de St. Joseph, who took it at Dinard.
AUTOLYTUS INERMIS de St. Joseph: Ann. Sci. Nat. Zool. I. 1886,
p.. 237.
PiymoutH. Occasional specimens have been taken on the
principal dredging grounds in the Sound, as well as on the trawling
grounds between Plymouth and the Eddystone and Eddystone and
Looe. The specimens all had the characteristic colour.
Breeding: With stolons in December, January, April, May and
June. One specimen in August had no stolon.
Torquay. One specimen (Elwes, Journ. M.B.A., vol. 8, 1908, p. 202).
Malaquin (Syllidiens, Lille, 1893, p. 76) makes a new genus, Avutoly-
tades for this species, in which the pharynx has a plain border,
without teeth of any kind.
MYRIANIDA PINNIGERA (Montagu): McIntosh, Mon. Brit. Ann. II. 1,
1908, p. 229. Malaquin, Syllidiens, Lille, 1893, Plate I, etc., as
M. fasciata Milne-EKdwards.
PiymoutH. Frequently met with in Plymouth Sound (w.é.) ;
dredgings from Millbay Channel, Asia and Queen’s Ground (T.V.H.,
R.A.T., E.J.A.); amongst Ascidians and sponges from the piles at
Millbay Dock (R.4.T., E.J.A.).
SALCOMBE. On the shore at the Salstone and dredged in the
channel to the west of the Salstone (Journ. M.B.A., vol. 6, 1900, p. 190).
PROCERASTEA HALLEZIANA Malaquin: Recherches sur les Syllidiens,
Lille, 1893, p. 81, Pl. XI. Figs. 1-14, Pl. VIII. Fig. 26.
PLyMouTH. Six specimens were obtained from amongst Ascidians
from a raft moored in Cawsand Bay, September 30th, 1914.
Breeding: The specimens bore no stolons, but in one specimen
three of the middle segments were considerably enlarged.
POLYCHETA OF PLYMOUTH. 507
HESIONID/.
MAGALIA PERARMATA Marion and Bobretzky: Annél. Golfe Marseille,
1875, p. 54. McIntosh, Mon. Brit. Ann. IT. 1, 1908, p. 136.
Piymouts. Not uncommon in dredgings from Millbay Channel,
Asia Shoal, Queen’s Ground and Duke Rock. From trawl material,
Rame-Eddystone ground. From scrapings from piles at Millbay
Dock.
Torquay. Common among Laminaria roots (Zlwes, Journ. M.B.A.,
vol. 8, 1908, p. 350).
OXYDROMUS PROPINQUUS Marion and Bobretzky : Annél. Golfe Marseille,
1875, p. 51, as Gyptis propinqua. de St. Joseph, Ann. Sci. Nat.
Zool. V. 1887, p. 321.
PrymoutH. Not uncommon in dredgings from near New Grounds
Buoy from January to April.
Breeding: Females with well-developed eggs, January to April.
OpHIoDROMUS FLEXUOSUS Delle Chiaje: McIntosh, Mon. Brit. Ann. I.
1, 1908, p. 117.
PiymoutH. Three or four specimens have been obtained from
the Looe-Eddystone trawling grounds.
CasTALiA PuNCTATA (QO. F. Miller): McIntosh, Mon. Brit. Ann. II. 1,
1908, p. 121.
PrymoutTH. Common in dredgings from Millbay Channel and
Asia Shoal; occasionally from Duke Rock and Queen’s Ground.
A few specimens from rough grounds outside the Sound, e.g. 2
miles off Yealm Head and 2 miles 8.W. by W. of Eddystone.
It was taken by Crawshay 17-5 miles 8. 25° W. of the Eddystone
in 42 fathoms (Journ. M.B.A., vol. 9, 1912, p. 340).
CASTALIA FUSCA (Johnston): McIntosh, Mon. Brit. Ann. I. 1, 1908,
prelate
PiymoutH. On the shore under stones and amongst the roots
of weeds from Drake’s Island, Rum Bay and Mount Edgcumbe ;
from the piles at Millbay Dock. Amongst dredgings from Millbay
Channel and Asia Shoal. Recorded in the previous list as Kefer-
steinia cirrata (Keferstein).
Torguay. Common under stones, especially at Meadfoot ;
also in Laminaria roots (Elwes, Journ. M.B.A., vol. 8, 1909, p. 350).
AMPHINOMIDE.
SPINTHER MINIACEUS Grube: McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 232.
PrymoutH. Half a dozen specimens living on a sponge dredged
at Duke Rock, February 6th, 1906.
Breeding : Ripe females, depositing eggs.
608 E. J. ALLEN.
EUPHROSYNE FOLIOSA Audouin and Edwards: McIntosh, Mon. Brit.
Ann. I. 2, 1900, p. 234.
PiymoutTH. Occasional specimens in dredgings from Queen’s
Ground, Asia Shoal and Millbay Channel (T.v.H., R.A.T., E.J.A.).
Kddystone Grounds.
One specimen 40 miles 8. 24° W. of Eddystone in 49 fms. (Craw-
shay, Journ. M.B.A., vol. 9, 1912, p. 341).
HxmoutuH. One specimen dredged amongst sponges (Journ. M.B.A.,
vol. 6, 1902, p. 318).
APHRODITIDE.
APHRODITA ACULEATA Linn. : McIntosh, Mon. Brit. Ann. I. 2, 1900, p. 247.
PiymoutH. On most of the fine-sand grounds off Plymouth,
between 20 and 30 fms, (T.V.H., R.A.T., E.J.A.) 8.8.W. of the Eddy-
stone to 42 fms. (Crawshay, Journ. M.B.A., vol. 9, 1912, p. 340).
SALCOMBE. One small specimen from Millbay Sands (Journ. M.B.A.,
vol. 6, 1900, p. 190).
Torquay. Thrown up on shore after heavy weather, especially
at Anstey Cove and Tor Abbey Sands (Hiwes, Journ. M.B.A., vol. 9, 1910,
p. 59).
HERMIONE HYSTRIX (Savigny): McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 264.
PitymoutH. Most frequently on gravel grounds in the neigh-
bourhood of the Eddystone (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 240) :
occasionally on similar ground in about 20 fms. (R.A.T., E.J.A.).
8.8.W. of the Eddystone to 50 fms. on rough ground (Crawshay,
Journ. M.B.A., vol. 9, 1912, p. 340).
LEPIDONOTUS sQUAMATUS (Linn.): McIntosh, Mon. Brit. Ann. I. 2,
1900, p. 274.
PrymoutH. Under stones and amongst weeds, Hydroids,
Polyzoa, etc.: from low-tide mark to 30 fms. and over, common
and widely distributed (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 240).
S.S.W. of the Eddystone to 42 fms. (Crawshay, Journ. M.B.A., vol. 9,
1912, p. 340).
SALCOMBE. Dredged in the channel between the Salstone and
Snape’s Point, as well as in the channel in Saleombe Harbour. It
was also obtained under the Marine Hotel (Hodgson, Journ. M.B.A., vol. 6,
1900, p. 190). .
Torquay. Two or three under stones on Babbacombe Beach
(Elwes, Journ. M.B.A., vol. 9, 1910, p. 59).
LEpiponotus cLAVA (Montagu): McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 280.
Pitymoutu, Everywhere on the shore under stones, especially
POLYCHATA OF PLYMOUTH. 609
at extreme low water (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 241):
less frequently in dredgings from the Sound.
Exmouta. Not uncommon on the shore at Orcombe Rocks
(Journ. M.B.A., vol. 6, 1902, p. 318).
Torquay. Occasionally found on all the beaches. Numerous
specimens on a large buoy in Torquay Harbour (Zlwes, Journ. M.B.A.,
vol. 9, 1910, p. 59).
GATTYANA CIRROSA (Pallas): McIntosh, Mon. Brit. Ann. I. 2, 1900,
p- 285.
PriymoutH. In dredgings from the neighbourhood of the Eddy-
stone (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 242). Yealm Sand Bank
and east shore, commensal in tubes of Amphitrite Johnstons.
SALCOMBE. Found on the shore living in the tubes of Amphitrite
Johnstoni on the Salstone, south of Halwell Point and near the
mouth of Salcombe Harbour (under Marine Hotel) (Hodgson, Journ.
M.B.A., vol. 6, 1900, p. 190).
Kunoa noposa (M. Sars): McIntosh, Mon. Brit. Ann. I. 2, 1900,
pa 2g
One specimen from the stony ground off Prawle Point, in 30 fms.
(Weldon, Journ. M.B.A., vol. 5, 1899, p. 478).
LAGISCA EXTENUATA (Grube): Fauwvel, Résult. Camp. Sci. Monaco.
Fas. XLVI. Annél. Polych. 1914, p. 62. McIntosh, Mon. Brit.
Ann. I. 2, 1900, p. 298 as ZL. floccosa (Savigny)=L. propinqua
Malmeren.
PiymoutH. Between tide-marks and in dredgings throughout
the whole area to 30 fms. (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 247 as
L. floccosa. At many stations 8.S.W. of the Eddystone to about
50 fms. (Crawshay, Journ. M.B.A., vol. 9, 1912, p. 340, as L. floccosa).
Torquay. Fairly common under stones (Ziwes, Journ. M.B.A., vol. 9,
1910, p. 59).
Note. Two varieties of this species occur in the Plymouth
district. (1) A littoral and inshore variety, in which the elytron
bears on its edge a few minute scattered cilia only, whilst the sur-
face is covered with small tubercles slightly conical in shape and of
fairly uniform size (a few being slightly larger than the rest) and has
a number of large, brown, globular papille near the posterior border.
(2) A deeper water variety found on the dredging and trawling
grounds from 20 to 50 fms., in which the elytra bear on their edges
a continuous row of minute cilia, almost spherical in shape. The
surface of the elytron is covered with small tubercles as in the
littoral variety, but scattered over the surface both towards the
centre and especially towards the exterior and posterior borders
a number of the tubercles are greatly enlarged, so that they stand
out as strong conical spines. Those near the posterior border are
the largest and their ends may appear rounded and swollen, but
610 By (ADLEN:
they do not attain the size of the large globular papille oi the
httoral form. This deeper water form approaches the L. rarispina
of Malmgren, and was so entered in our previous lists. The spines
do not, however, attain the length indicated in Malmeren’s figures
(Nordiska Hafs-Annulater, 1865. Tafl. VIII. figs. 2 and 2c).
With regard to the name of the species, Fauvel (loc. cit.) pomts
out that Savigny’s L. floccosa is described by its author as having
sixteen pairs of elytra, and his description is too incomplete to
fix even the genus to which it belongs. The first recognisable deserip-
tion of the present form is by Grube with the specific name extenuata.
By this name it has been generally referred to in the literature or
by its later synonym L. propinqua Malmeren.
The species referred to in previous lists by Hodgson and Elwes
from Plymouth and Torquay (loc. cit.) as L: extenuata Grube, is I
believe L. Elisabethe McIntosh.
LAGISCA ELISABETH McIntosh: Mon. Brit. Ann. I. 2, 1900, p. 303.
PrymoutH. On the shore at Wembury Bay and Rum Bay, not
uncommon. Probably the form referred to by Hodgson (Journ. M.B.A.,
vol. 6, 1900, p. 247) as L. extenuata Grube.
Torquay. Very common in roots of Laminaria and under
stones (Elwes, Journ. M.B.A., vol. 9, 1910, p. 59). Southern has
examined specimens from Torquay sent by Major Elwes and states
that they are certainly this form (Proceed. R. Irish Acad. XX XI, 47, 1914,
p. 51).
HARMOTHOE ImBrRicaTA (Linn.): McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 314.
PrymoutH. Between tide-marks amongst Laminaria roots on
the Breakwater : amongst Hydroids, Polyzoa, etc., on Hddystone
Grounds (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 245).
This form seems to be rare at Plymouth, and I have not suc-
ceeded in re-finding it.
HARMOTHOE SPINIFERA (Ehlers): McIntosh, Mon. Brit. Ann. I. 2,
1900, p. 327.
PiymoutH. Amongst dredgings from Millbay Channel, Queen’s
Ground, Asia Shoal, ete., and Yealm River: common (T.v.H.,
RATE cose)
SALCOMBE. Dredged in the channel west of the Salstone, and
between the Salstone and Snape’s Point (Hodgson, Journ. M.B.A., vol. 6,
1900, p. 190).
Torquay. One specimen only found (Elwes, Journ. M.B.A., vol. 9,
1910, p. 59).
HARMOTHOE LUNULATA (Delle Chiaje): McJntosh, Mon. Brit. Ann. I.
2, 1900, p. 342.
Piymouts. A not uncommon tidal form. Found among roots
of Laminaria on the Breakwater, and occasionally under stones
POLYCHETA OF PLYMOUTH. 611
near low water (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 243). One
specimen 8.8.W. of Eddystone in 49 fms. (Crawshay, Journ. M.B.A.,
vol. 9, 1912, p. 341).
SatcomMBE. On the shore of the bay north of Pilworthy Point
(Hodgson, Journ. M.B.A., vol. 6, 1900, p. 190).
HARMOTHOE SETOSISSIMA (Savigny): McIntosh, Mon. Brit. Ann. I. 2,
1900, p. 345.
PiymoutH. Occasionally found among Polyzoa (Cellaria) and
Chetopterus tubes from the Eddystone Grounds (Hodgson, Journ. M.B.A.,
vol. 6, 1900, p. 244). S.S.W. of the Eddystone in 43-49 fms. (Crawshay,
Journ. M.B.A., vol. 9, 1912, p. 341).
SALcoMBE. On the eastern shore of Salcombe Harbour (Hodgson,
Journ. M.B.A., vol. 6, 1900, p. 190).
HARMOTHOE AREOLATA (Grube): McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 349.
PrymoutH. Not uncommon on the Eddystone Grounds, where
the dredge or trawl brings up masses of Polyzoa, Hydroids and
Chetopterus tubes (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 244).
HARMOTHOE FRASER-THOMSONI McIntosh: Mon. Brit. Ann. I. 2, 1900,
p. 337.
PiymoutH. Two specimens §.8.W. of the Eddystone in 49-
51 fms. (Crawshay, Journ. M.B.A., vol. 9, 1912, p. 341).
HARMOTHOE MARPHYSZ McIntosh: Mon. Brit. Ann. I. 2, 1900, p. 339.
PrymoutH. Prof. McIntosh records this species from the
galleries of Marphysa sanguinea from chinks in the rocks, Polperre
(British Museum). It was found at Plymouth by Mr. R. A. Todd
commensal with Marphysa sanguinea on the shore at Mount Edg-
cumbe.
A form which seems to resemble H. marphyse nore closely than
any other described species has been met with in fine sand in the
Yealm Estuary. In one case the sand contained Amphitrite John-
ston, in another Synapta inherens, and a definite association of
the Harmothoé with the Synapta was actually observed in one
instance.
ERARNE IMPAR (Johnston) : McIntosh, Mon. Brit. Ann. I. 2, 1900, p. 353.
PrymovutTH. Common between tide-marks and amongst dredg-
ings throughout the Plymouth area (T.v.H., E.J.A.): Hddystone
Grounds (T.v.H.). 8.S.W. of Eddystone in 40-42 fms. (Crawshay, Journ.
M.B.A., vol. 9, 1912, p. 341).
SALcoMBE. Dredged in the channel between the Salstone and
the mouth of Salcombe Harbour (Hodgson, Journ. M.B.A., vol. 6, 1900,
p. 190).
ExmovutH. On the shore west of the mouth of Salthouse Lake
(Journ. M.B.A., vol. 6, 1902, p. 318).
612 E, J. ALLEN,
Torquay. Rare. Recorded by Gosse from Anstey’s Cove (Elwes,
Journ. M.B.A., vol. 9, 1910, p. 59).
SCALISETOSUS COMMUNIS (Delle Chiaje): McIntosh, Mon. Brit. Ann. I.
2. 19005 70: ai.
PiymoutH. On the shore at Mount Edgcumbe: amongst
dredgings Millbay Channel and Asia Shoal (R.A.7., E.J.A.).
Fauvel considers that the name S. pellucidus (Ehlers) should be
maintained for this species, as there is great doubt as to Delle
Chiaje’s species (Camp. Sci. Monaco, XLVI. 1914, p. 47).
SCALISETOSUS ASSIMILIS (McIntosh): McIntosh, Mon. Brit. Ann. I. 2,
19005p. 377.
PiymoutH. Among spines of Hchinus esculentus from Mewstone
and Kddystone Grounds (T.v.H., R.A.T., E.J.A.).
MALMGRENIA CASTANEA, McIntosh: Mon. Brit. Ann. I. 2, 1900, p. 379.
PiymMoutH. Commensal on the surface of Spatangus purpureus,
near the mouth of the Echinoderm : not uncommon (T.V.H., E.J.A.).
HALOSYDNA GELATINOSA (M. Sars): McIntosh, Mon. Brit. Ann. I. 2,
1900, p. 384.
PiymoutH. Frequently met with on the shore under stones
and amongst dredging and trawling material throughout the area,
including the Eddystone Grounds.
One specimen taken by Crawshay 8.8.W. of the Eddystone in
49 fms. (Journ. M.B.A., vol. 9, 1912, p. 341).
Torquay. One specimen under a stone at Babbacombe Beach
(Elwes, Journ. M.B.A., vol. 9, 1910, p. 60).
POLYNOE SCOLOPENDRINA Savigny Auct.: McIntosh, Mon. Brit. Ann.
I. 2, 1900, p. 389. Marenzeller, Zur Kenntniss der adriatischen
Anneliden. Sitzb. math-nat. Cl. Wien. 69, 1874, p. 420 as P.
Johnston.
PiymoutH. Commensal in tubes of Polymnia nebulosa on the
shore at Mount Edgcumbe. In dredgings from Asia Shoal.
Kddystone Grounds (Hodgson, Journ. M.B.A., vol. 6, 1900, p. 249).
The specimens commensal with Polymnia nebulosa are large
(6 to 7 centimetres long) and the colour tends, especially in spirit,
to dark olive green. Those from dredgings in the Sound are smaller
(2-3 cm.) and the colour is ight brown. The elytra of the two
sides nearly or even quite meet in the middle line in both cases.
The dorsal bristle bundles are well developed. Three rows of dorsal
tubercles on the posterior segments are very marked.
POLYNOE CRASSIPALPA Marenzeller: Zur Kenntniss der adriatischen
Anneliden. Sitzb. math-nat. Cl. Wien. 69, 1874, p. 412.
PiymoutH. Occasional specimens are met with in dredgings
from Plymouth Sound.
When the two are seen side by side there can be no doubt that
POLYCHATA OF PLYMOUTH. 613
Marenzeller was right in separating this form from the P. scolo-
pendrina Savigny of Johnston and other authors. In P. crassipalpa
the body is much more slender and the dorsum is more strongly
pigmented, the dark brown colour being arranged in a characteristic
pattern. The posterior part of the ventral surface is also strongly
pigmented. The elytra are small, to quote Savigny “ separated by
an interval equal to their breadth, the two rows thus leaving all
the middle of the back uncovered; but the elytra of each row
mutually overlap a little ” (Syst. des Annélides, p. 25). This character
and the complete absence of tubercles on the uncovered, posterior
part of the dorsum give the species a quite characteristic appearance
to the naked eye or under a low power lens. The bristles of the
dorsal bundle in the typical foot are few, two or three only in one
specimen examined by me, six in Marenzeller’s specimens, and
spinous rows are little developed on them. The ventral bristles as
well as other details of the worm are well described by Marenzeller.
The latter author, however, in my opinion, attaches undue import-
ance in distinguishing the species of this genus to the relative lengths
of the median tentacle, palps and tentacular cirri, especially as these
have apparently been noted both by himself and by other authors
only on preserved specimens. The palps especially seem to be
subject to considerable and very variable degrees of contraction
under the influence of preservatives. In a well preserved specimen
which shows little sign of contraction I find the median tentacle
just a little longer than the palps, and the dorsal tentacular cirri about
the same length as the median tentacle. The palps taper gradually
to a point and are not shaped as in Marenzeller’s figure, which seems
to have been drawn from a specimen in which they were much
contracted.
Although I have not much doubt that Savigny’s description
applies to the present species it is impossible to be quite certain
on the point, and it therefore seems better to use P. scolopendrina
for the other form, which has been known under that name for half
a century, and to call the present one P. crassipalpa, the name
under which it was first clearly described by Marenzeller.
LEPIDASTHENIA ARGUS Hodgson: Journ. M.B.A., vol. 6, 1900, p. 250.
SatcomBe. Found in the tubes of Amphitrite Edwardsi, on the
shore between Salcombe town and Sandhill Pomt (under Marine
Hotel) (T.v.H.).
The species has since been taken on many occasions in the same
locality and under the same conditions as originally described by
Hodgson. It has never been found elsewhere.
ACHOLOE ASTERICOLA (Delle Chiaje): McIntosh, Mon. Brit. Ann. I. 2,
1900, p. 397.
In the ambulacral groove of Astropecten irreqularis : common
(rye) RUACT HJ),
614 E. J. ALLEN,
STHENELAIS BOA (Johnston): McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 408.
PriymoutH. Common in sand between tide-marks, Rum Bay,
Drake’s Island, Mount Edgcumbe, Wembury Bay, Yealm River
(T.V.H., R.A.T., E.J.A.): occasionally amongst dredgings from Mill-
bay Channel and Asia Shoal (t.v.H., £.3.A.): Mewstone Grounds
(T.V.H.).
SaLcoMBE. On the Salstone and near the mouth of the harbour,
between the Ferry House and Millbay ; never numerous. Dredged
in the channel between Salstone and Snape’s Point (Journ. M.B.A.,
vol. 6, 1900, p. 191).
ExmoutTH. One specimen in the channel; never met with on
the shore (Journ. M.B.A., vol. 6, 1902, p. 318).
Torquay. Not uncommon in the sand at Tor Abbey Sands
(Elwes, Journ. M.B.A., vol. 9, 1900, p. 60).
STHENELAIS LIMICOLA, Ehlers: McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 417.
PiymMoutH. One specimen in a coarse townet attached to the
Otter-trawl, 5 miles W.S.W. of Rame Head. One specimen dug
in the sand bank in the upper part of the Yealm River.
SIGALION MATHILD# Audouin and Edwards: McIntosh, Mon. Brit.
Ann. I. 2, 1900, p. 427.
TEIGNMOUTH. One specimen obtained in the sand below Shaldon
Bridge.
PHOLOE miINUTA (Fabricius): McIntosh, Mon. Brit. Ann. I. 2, 1900,
p. 437.
PLymMouTH. Common amongst dredging and trawling material
over the whole Plymouth area, including Eddystone Grounds.
Especially abundant in Millbay Channel and on Asia Shoal.
Torquay. The most numerous of all the Torquay Aphroditide,
inhabiting especially the Laminarian zone (Elwes, Journ. M.B.A., vol. 9,
1910, p. 60).
PHYLLODOCIDA:.
NoOTOPHYLLUM FOLIOSUM (Sars): McIntosh, Mon. Brit. Ann. II. 1,
1908, p. 46.
PiymoutH. Frequent in dredgings from all the grounds in the
Sound, and often met with on all the dredging and trawling grounds
outside, including the Eddystone Grounds.
In the previous list this species was wrongly named Eulalia obtecta
Ehlers.
Torquay. One from Livermead (Hlwes, Journ. M.B.A., vol. 8, 1909,
p. 349). :
POLYCHATA OF PLYMOUTH. aes
EULALIA BILINEATA (Johnston) : McIntosh, Mon. Brit. Ann. II. 1, 1908,
peo.
PiymoutH. Frequent amongst dredgings from the Sound,
especially from Millbay Channel and Asia Shoal. Dredged off
Yealm Head. Amongst roots of Laminaria from Cawsand Bay.
EULALIA AUREA Gravier: Recherches sur les Phyllodociens, Bull. Sci.
France et Belg. XXIX. 1896, p. 309.
PLtymMoutTH. Common on all the dredging grounds in Plymouth
Sound. Occasional specimens are met with on most of the grounds
near shore, e.g. off Yealm Head.
McIntosh (Mon. Brit. Ann. II. 1, 1908, p. 60) regards E. aurea
as a variety of EH. viridis. The general shape of the animal, the
character of its movements, its size when mature and its usual
habitat seem to mark it clearly from that form. The most striking
difference is, however, the distinctive colour and colour pattern of
each of the forms, which is very constant. In most respects
E. aurea seems nearer to F. bilineata than to EF. viridis.
Breeding : With eggs January to July (R.4.7., E.J.A.).
Torquay. On the shore, but not above the Laminarian zone
(Zlwes, Journ. M.B.A., vol. 8, 1909, p. 348).
KULALIA oRNATA de St. Joseph: Ann. Sci. Nat. Zool. V. 1888, p. 291.
PiymoutH. In dredgings from the Sound, especially Millbay
Channel and Asia Shoal. Much less frequent than FH. aurea.
McIntosh (Mon. Brit. Ann. IL 1, 1908, p. 59) regards this form also
as a variety of H. viridis. The well-marked colour pattern, its general
shape and the character of its movements appear to me to justify
doubts as to this conclusion.
Torquay. Fairly common, but not above the Laminarian zone
(Elwes, Journ. M.B.A., vol. 8, 1909, p. 347).
Kuba. viripis (O. F. Miller): McZntosh, Mon. Brit. Ann. II. 1, 1908,
p- 59.
PiymMoutTH. Common on rocky shores in the Sound and on the
coast. Its usual home seems to be amongst shore sea-weeds, to
which the large gelatinous masses of green eggs are attached. It
is, however, occasionally taken in dredgings from the Sound, es-
pecially in an immature state, and specimens have even been taken
on the Eddystone Grounds.
Breeding: Eggs in January and February; abundant in May
and June. None found at end of July or in August (A.J.s.).
SaLcoMBE. From dredgings between Salstone and Snape’s Point
(Journ. M.B.A., vol. 6, 1900, p. 193).
ExmoutH. ‘Two specimens were obtained from Orcombe Rocks,
at the mouth of the estuary (Journ. M.B.A., vol. 6, 1902, p. 320).
Torquay. Particularly abundant where the limestone rocks
616 Eg. ALLEN,
have been much eaten away from about half-tide mark downwards.
It appears to like crawling about the damp rocks out of the water
when the tide is low (Elwes, Journ. M.B.A., vol. 8, 1909, p. 347).
EULALIA TRIPUNCTATA McIntosh: Mon. Brit. Ann. II. 1, 1908, p. 63.
de St. Joseph, Ann. Sci. Nat. Zool. V. 1888, p. 285, as #. Claparedit.
PrymoutH. Not infrequent in dredgings from Millbay Channel,
Asia Shoal and occasionally Queen’s Ground and Duke Rock.
Found also on the outer grounds, e.g. off Yealm Head. Cawsand
Bay, among Laminaria roots from the shore. Recorded in the
former list as #. Claparedt.
Breeding: May, eggs brick-red.
KULALIA PUNCTIFERA (Grube): McIntosh, Mon. Brit. Ann. II. 1, 1908,
p. 53 as Bulalia nebulosa, Montagu.
PrymoutH. In dredgings from Millbay Channel, Asia Shoal and
Yealm ; on the shore at Mount Edgcumbe and in the Yealm Estuary.
SALCOMBE. Dredged in the channel between the Salstone and
Snape’s Point (Journ. M.B.A., vol. 6, 1900, p. 193).
Torquay. One specimen from Corbyn’s Head (Elwes, Journ. M.B.A.,
vol. 8, 1909, p. 348).
KULALIA (PTEROCIRRUS) MACROCEROS (Grube): McIntosh, Mon. Brit.
Ann. IT. 1, 1908, p. 60.
PrymoutH. Occasional specimens from dredging grounds in
the Sound. A number also taken in dredging from 2 miles off Yealm
Head.
EuLaALiA (KUMIDA) SANGUINEA Oersted: McIntosh, Mon. Brit. Ann.
Tet 1908366:
PiymoutH. Common and generally distributed in dredging
material throughout the area, especially in inshore waters. Frequent
amongst Laminaria roots from the shore.
Breeding: May to July; eggs green, occasionally reddish.
The species shows considerable variety both of form and colour,
and it seems probable that McIntosh has included under this name
several forms which may prove to be distinct species.
One variety with alternate green and white bands on the dorsum
(Eulalia Sp. B. McIntosh, l.c., p. 68), When seen alive appears to be
specially distinct. Southern (Proceed. R. Irish Acad. XX XI. 47, 1914, p. 66)
has also found this variety on the west coast of Ireland.
In the former list the present species was entered under the name
of Eulalia pallida Claparéde, with a reference to de St. Joseph’s
description.
Torquay. Common among Laminaria roots (Hiwes, Journ. M.B.A.,
vol. 8, 1909, p. 348).
PHYLLODOCE LAMELLIGERA (Gmelin): McIntosh, Mon. Brit. Ann. I.
1, 1908, p. 76.
POLYCHETA OF PLYMOUTH. 617
Between tide-marks Drake’s Island: Breakwater: in dredgings
from Millbay Channel, Asia Shoal, Duke Rock (T.v.H., E.J.A.).
Recorded in the former list as P. laminosa, Savigny.
Torauay. One light coloured individual under a stone at
Hope’s Nose, and another of normal colouring at Meadfoot (Elwes,
Journ. M.B.A., vol. 8, 1909, p. 349).
PHYLLODOCE PARETTI (Blainville): McIntosh, Mon. Brit. Ann. I. 1,
1908, p. 82.
PiymoutH. Occasional specimens in dredgings from the Mew-
stone Ledge (£.5.4.): off Stoke Point (s.P.).
Torquay. The head and about twenty segments of one from
Corbyn’s Head (Elwes, Journ. M.B.A., vol. 8, 1909, p. 349).
PHYLLODOCE MACULATA (Linn.): McIntosh, Mon. Brit. Ann. II. 1,
1908, p. 89.
PrymoutH. Common in dredgings from the Sound and inshore
waters, being sometimes present in very large numbers. It seems
to be much more abundant during the summer months than in
winter. Large specimens which seem to be the same species were
found in fine clean sand at Wembury Bay.
Breeding. January, February (w.c.): April to July. Eggs
orange-brown or green (E.J.A.).
Exmoutu. ya saccew.sumessscesch cect eeasseswaneaceen soe
eee eee eee ey
720 14
13 10 1
3
1
Gr.
1,772
64
81
$9
183
19
29
734
Sods
3 8
0
13h)
5 8
On
011
ies:
2
Examined and found correct,
21st January, 1915.
£2,983 5 1
(Signed) N. E. WATERHOUSE.
J. O. BoRLEY.
Epwarp T. BrowNe.
P. CHALMERS MITCHELL.
[ 656 ]
Marine Biological Association of the United Kingdom.
Lise
OF
Governors, Founders, and Fembers.
Isr May A915.
* Member of Council. + Vice-President. + President.
Ann. signifies that the Member is liable to an Annual Subscription of One Guinea.
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Subscription.
I.— Governors,
The British Association for the Advancement of Science, Ls gton
TOW ees ccs uta date oto weed Uk Sea eee Re ee ee ee ee £500
The Universityot @xdord’ 30.0 0..Gce cacts sects eect ee eee eee £500
The Umiversitysof @amibrideer...7 cat otucaecceccsec ete ae nee eee £500
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Bayly; Robert:(the late) “2.0. ..20 scat arsuan ea aeeetes eke eae tee eer £1000
Bayly, :Johm: (tre 1ate) ss ccccccsestonaseeaicstebe che tee ace teeee ee eee £600
Mhomasson, J: P\(thetlate) src. access veeeeaseeatanc tees ootec te eee nee £970
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1884 The Royal Society, Burlington House, Piccadilly, W. ...ccccccscccseeenees £350
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[334 ‘Bulteel) Whos<(the late) f.cfestcecctessncss-pecesee sees tea oon eee meee £100
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{1884 Lankester, Sir E. Ray, K.C.B., F.R.S., 29, Thurloe Place, South
Kensington (SW. c voeaswobinncoersgis Ann.
658 LIST OF GOVERNORS, FOUNDERS, AND MEMBERS.
1898 Bowles,iCol. Heury, Morty Hall, Hafield 0s. ..onsstee asd eee ee eee Ann
1910 Bradford, Sir J. Rose, K.C.M.G., M.D., D.Sc., F.R.S., 8, Manchester
Square, London, Wiis cieceksne sodsaachososesaessa tones eee Ann.
1902 Brighton Public Library (Henry D. Roberts, Chief Librarian) ......... Ann.
1886 Brooksbank, Mrs. M., Letg i Place Godstone, Surrey s.cec.rsesseeeseeades uae C.
1884 Brown, Arthur W. W. ,62, Carlisle Mansions, Carlisle Place, London, S.W. C.
*1893 Browne, Edward T., Ba, Anglefield, Berkhamsted .......cecscscscserscees Ann
1892 Browne, Mrs. E..T., Anglefield, Berkhamsted 0. ..ccs00cessccennsesecuceoeenet Ann.
*1897 Byrne, L. W., B.A., 7, New Square, Lincoln’s Inn, London, W.C......44. Ann.
1908 Calman, Dr. W. T., British Museum (Natwral History), Cromwell
COO WOW ws erictticlat Ae Nee amas eet aukatme oe rae ee Lee. See SAE E RET nee Ann.
1912 Cavers, Dr. F., Goldsmiths’ College, New Cross, London, S.H.......0cc000008 Ann.
1913°Childs, Christopher, M.D.; Boscarne, Looe’. .s..0.cs.c.ssse- acer os eeeee etme Ann.
IV.— Associate Members.
Caux, J. W. de, Great Yarmouth.
Dunn, Howard, Mevagissey, Cornwall.
Dunn, Matthias, J.P., Newlyn, Cornwall.
Edwards, W. C., Mercantile Marine Office, St. Andrew’s Dock, Hull.
Freeth, A. J., Fish Quay, North Shields.
Hurrell, H. E., 25, Regent Street, Yarmouth.
Inskip, H. E., Capt., R.N., Harbour Masters Office, Ramsgate.
Johnson, A., Fishmongers’ Company, Billingsgate Market, London, E.C.
Olsen, O. T., F.L.S., F.R.G.S., Fish Dock Road, Great Grimsby.
Patterson, Arthur, [bis House, Great Yarmouth.
Ridge, B. J., Newlyn, Penzance.
Sanders, W. J., Rockvall, Brixham.
Sinel, Joseph, 8, Springfield Cottages, Springfield Road, Jersey, CI.
Wells, W., The Aquarium, Brighton.
[ 663
|
INDEX.
x
Abstracts of Memoirs recording work
done at the Plymouth Laboratory,
513
Acanthochasmus tmbutiformis, 472, 488,
497, 503
Acanthocites fascicularis, 108
Acanthodoris pilosa, 110
Acartia, experiments in keeping, 561,
566
Acholoé astericola, 613
Acmaea virginea, 109
Actinia equina, 106
Actiniae, Comparative Anatomy of
some British, 521
Holidia pupillosa, 110
Aolidiella angulata, 110
— glauca, 110
Agonus cataphractus, host of Derogenes,
487
Ahnfeldtia plicata, 105
Alcyonidium hirsutum, 108
Alcyonium ficus, synonymy of, 264
— pulmonis instar lobatum, 262
Algae of Cardigan Bay, 105
Allen, E. J., On the Culture of the
Plankton Diatom Thalassiosira gra-
vida Cleve, in Artificial Sea-water,
417
— Polychaeta of Plymouth and the
South Devon Coast, including a list
of the Archiannelida, 592
Amathia lendigera, 108
Amathilla homari, 111
Amblyosyllis lineata, 603
Ammodytes lanceolatus, 340; host of
Hemiurus, 484
— tobianus, 340, 467
NEW SERIES.—VOL. X,
Ammotrypane aulogaster, 638
Amphicteis curvipalea, 637
— Gunneri, 637
Amphiglena mediterranea, 643
Amphioxus, ciliary mechanisms on the
gill of, 22, 297 ; mode of feeding in,
20, 35, 298 ; hermaphrodite specimen
of, 506 ; experiments in rearing, 510
Amphiporus lactifloreus, 107
Amplitrite Edwardsi, 633
— gracilis, 633
— Johnstont, 633
Amphiura, 107
Ancula cristata, 110
Anemones, Some Plymouth, 60
Anemonia sulcata, 106
Anguilla vulgaris, host of Podocotyle,
473, Helicometra, 476, Lecithochirium,
485
Annelida, rate of growth in, 316
Anodonta cygnea, 323
Anomalocera Patersoni, experiments 112
keeping, 561
Anomia aculeata, rate of growth, 320
— ephippiwn, 110
Antenella secundaria, 260
— stliquosa, 261
Antennularia antennina, 440, 445
— ramos, 440, 445
Anthopleura alfordi, 536
Anthura gracilis, 236
Aonides oxycephala, 629
Aphroceras (Leucandra) cliarensts, found
near Plymouth, 258
Aphrodite aculeata, 608
Aphya pellucida, 372
Arabella (Maclovia) tricolor, 623
Archiannelida of Plymouth, 595
664 INDEX.
Archidoris tuberculata, 110
Arenicola branchialis, 640
— ecaudata, 640
— Grubet, 640
— marina, 108, 639
Aricia Cuviert, 627
— Latreilli, 627
Arnoglossus imperialis, 356
— laterna, 356
— thori, 356
Artificial sea-water, 421, 434
Ascidia conchilega, 324
Ascidians, ciliary mechanisms of, 33,
287 ; mode of feeding in, 30, 35
Ascidiella aspersa, life history, 324
Ascophyllum nodosum, 105
Asperococcus echinatus, 105
Asterias glacialis, development of, 2;
experiments with, 56; larva of, 4
— rubens, larva of, 4; in Cardigan
Bay, 107
— vulgaris, larva of, 4
Athanas mitescens, 112
Atherina presbyter, host of Podocotyle,
474 ; of Bacciger, 481
Aulactinia gelam, 536
Aureliania regalis, 550
Autolytus Edwarsi, 605
— ehbtensis, 605
— imermis, 606
— longtferiens, 604
— lugens, 606
— macrophthalma, 604
— pictus, 604
— prolifer, 605
— punctatus, 605
— rubropunctatus, 604
Aine belones, 472, 496, 502
Axius stirhynchus, 112
B
Bacciger bacciger, 470, 481, 500
Bacteria, influence of, in plankton ex-
periments, 572
Balance Sheet, 1912, 134; 1913, 414;
1914, 654
Balanoglossus, ciliation of the gill of,
37
Balanus balanoides, 111, 257; rate of
growth, 317
— perforatus, 111
Bangia fuscopurpurea, 105
Belone vulgaris, host of Axine, 496
Bipinnaria laevis, 5
— Russoi, 2
Bispira volutacornis, 642
Blennius gattorugine, 113 ; host of Helz-
cometra, 476, Zoogonoides, 483, Mon-
orchis, 484
— ocellaris, 379 ; host of Steringotrema,
480, Zoogonoides, 483, Derogenes, 487
— pholis, 113, 379; host of Peracrea-
dium, 476, Helicometra, 476, Lect-
thochirium, 485
Bothus maximus, host of Derogenes, 487
Botryllovdes sp., 112
Botryllus violaceus, 112 ; rate of growth,
325
Bougainvillea ramosa, 313
Bouvier, E. L. Recherches sur le
Développement post -embryonnaire ~
de la Langouste commune (Palinurus
vulgaris), 179
— Observations nouvelles sur les tra-
chelifer, larves luciferiformes de Jaxea
nocturna, 194
— Quelques mots sur la variabilité du
Pycnogonum littorale, Strom., 207
Bowerbankia imbricata, 108
— sp., rate of growth in, 317
Brachiopods, ciliary mechanisms in,
283 ; mode of feeding, 294
Branchiommea vesiculosum, 641
Bryopsis plumosa, 105
Bucephalopsis gracilescens, 472, 491
Bucephalus minimus, 472, 492, 497
— polymorphus, 489
Bugula flabellata, rate of growth in, 316
Bunodera nodulosa, 471, 487, 502
C
Caesicirrus neglectus, 639
Cainocreadium labracis, 469, 476, 497
Calanus finmarchicus, experiments in
keeping, 556, 559, 562, 565
Calicotyle kroyert, 473, 497, 503
Calliobdella lophaz, 81
INDEX. 665
Callionymus lyra, 378 ; host of Lebouria,
475, Zoogonoides, 483, Derogenes, 487
Calliopius laeviusculus, 111
Calliostoma zizyphinus, 109, 114, 115
Callithamnion hookeri, 105
Calyptraea, endostyle of, 303
Cancer pagurus, 112
Canthocamptus palustris, 111
Capitella capitata, 639
Caprella linearis, 111
Capres aper, 353 ; host of Pharyngora,
478, Hemiurus, 484, 485, Derogenes,
487
Caranz trachurus, 348
Carcinus maenas, 112; rate of growth,
318
Cardigan Bay, Fauna of, 102
Cardium edule, 111; rate of growth,
323
Castagnea griffithsiana, 105
— virescens, 105
Castalia fusca, 107, 607
— punctata, 607
Catanella spuntia, 105
Cellularia neritina, rate of growth in,
317
Centrolabrus exoletus, host of Lebouria,
475
Centronotus gunnellus, 113, 467 ; host
of Podocotyle, 473
Ceramium acanthonotum, 105
— ciliatum, 105
— diaphanum, 105
— rubrum, var. proliferwm, 105
— strictum, var. divaricata, 105
Ceratiwm arcticum, distribution of, 519
— longipes, distribution of, 519
Chaetomorpha melagoniwm, 105
— tortuosa, 105
Chaetopterus, rate of growth in, 316;
tubes containing Crystallogobius
eggs, 373
Chaetopterus variopedatus, 631
Chantransia virgatula, 105
Chondrus crispus, 105
Chorda filum, 105
Chlorodendron subsalsum, as food for
Plankton animals, 558, 574
Chordaria flagelliformis, 105
Chthamalus stellatus, 111
Ciliary mechanisms, 19, 283
Ciona intestinalis, life history, 324
Cirratulus (Audouinia) tentaculatus, 632
— cirratus, 108, 632
— norvegicus, 632
Cladophora albida, 105
— pellucida, 105
— sericea, 105
Cladostephus spongiosus, 105
— verticillatus, 105
Clark, R. S. General Report on the
Larval and Post-Larval Teleosteans
in Plymouth Waters, 327
Clavellina lepadiformis, 324
Clupea pilchardus, host of Hemiwrus,
485
— sprattus, 467
Clupeidae, larval and post-larval, 338
Clytia Johnstoni, 313
Coelenterata, of Cardigan Bay, 106;
rate of growth, 313
Colochirus lacazei, 226, 229
Conchidiwm Knighti, 295
Conchoderma aurita, rate of growth, 317
— virgata, rate of growth, 317
Conger conger, host of Helicometra, 476,
Lecithochirium, 485, Derogenes, 487,
Prosorhynchus, 494
Corallina officinalis, 105
Corynactis albida, 550
— annulata, 550
— australis, 544, 550
— corned, 544, 548
— globulvfera, 550
— gracilis, 550
— Haddoni, 559
— Hertwigi, 550
— hoplites, 545, 548
— mollis, 550
— myrcid, 545, 548
— viridis, 543, 548
Coryne vaginata, 106
Cottus bubalis, 118, 375 ; host of Podo-
cotyle, 473, Hermiurus, 484, Dero-
genes, 487, Prosorhynchus, 494
Crangon vulgaris, 111
Crania, mode of feeding in, 284
Crawshay, L. R. Report on the Dis-
tribution of the Microplankton
[Abstract], 518
666 INDEX.
Crawshay, L. R. Notes on Experi-
ments in the Keeping of Plankton
Animals under Artificial Conditions,
555 :
—A Method of Separating Sponge
Spicules by Filtration, 590
Crenilabrus melops, 113; host of Le-
bowria, 475, Peracreadiwm, 475,
Synaptobothrium, 486
— rupestris, 113
Crepidula, endostyle of, 303; rate of
growth, 320, 323 ; age of sex-change,
322
Crisia cornuta, L108
— denticulata, 108
Crustacea, rate of growth in, 317
Crystallogobius nilssoni, 372
Ctenodrilus pardalis, 596
Ctenolabrus rupestris, 347, 392 ; host of
Lebouria, 475, Helicometra, 476
Cucumaria elongata, 227, 229
— frondosa, 223
— hyndmanni, 223
—- lefevret, 226
— montagur, 222, 225
— normani, specific characters, 211 ;
synonymy of, 228, 225
— pentactes, 223, 231
— planct, 223
— saxicola, specific characters of, 211 ;
synonymy of, 223, 225
Cyathura carinata, 239
Cyclogaster montagui, 376; host of
Podocotyle atomon, 473
Cyclopterus lumpus, 118, 376; host of
Pharyngora, 478, Derogenes, 487
D
Dasychone, growth rate in, 316
Dasychone bombyz, 642
De Morgan, W., and Drew, G. H. A
Study of the Restitution Masses
formed by the Dissociated Cells of
the Hydroids Antennularta ramosa
and A. antennina, 440
Dendy, A. On the Occurrence of
Aphroceras (Leucandra) cliarensis
Stephens near Plymouth, 258
Derogenes varicus, 471, 487, 497, 498,
499, 501, 502, 508
Derogenoides ovacutus, 471, 487, 498
Desmarestia aculeata, 105
Dexamine spinosa, 111
Diatom cultures in artificial sea-water,
417, 425, 570
Dictyosiphon foeniculaceus, 105
Dictyota dichotoma, 105
Dinophilus gyrociliatus, 595
— taeniatus, at Cardigan Bay, 107;
rate of growth, 316; at Plymouth,
595
Dodecaceria concharum, 632
Donaz vittatus, 111
Doto coronata, 110, 323
Dromia vulgaris, 112
E
Echinodermata of Cardigan Bay, 106
Echinoderms, Development of, 1
Echinus acutus, experiments with, 55,
57, 256, 464
— esculentus, experiments with, 56 ;
256, 464
— miliaris, experiments with, 55, 57,
465 ; breeding habits, 254
Ectocarpus confervoides, var. siliculosa,
105
— tomentosus, 105
Edwardsia claparedi, 61
— timida, 60
Elachista fuctcola, 105
Eloactis mazeli, 68, 70
Enteromorpha compressa, 105
— intestinalis, 105
— linza, 105
Ephesia gracilis, 625
— peripatus, 626
Eteone picta, 616
— pusilla, 618
Eulalia wurea, 615
— bilineata, 615
— Claparedir, 616
— (Eumida) sanguinea, 616
— nebulosa, 616
—- obtecta, 614
— ornata, 615
— pallida, 616
INDEX. 667
Eulalia (Pterocirrus) macroceros, 616
— puncetifera, 616
— tripunctata, 616
— viridis, 107, 615
Eunice fasciata, 624
— Harasii, 624
— vittata, 624
KHunoa nodosa, 609
Eupagurus bernhardus, 112
Euphrosyne foliosa, 608
Euplotes, action on Bacteria, 573
Eurysyllis paradoxa, 600
Eusyllis lamelligera, 599
— monilicornis, 599
— tubifex, 599
Evaluation of the Sea, 312
Evarne impar, 611
Exogone gemmifera, 597
Experiments in the keeping of Plank-
ton animals, 555
F
Fabricia sabella, 643
Facelina coronata, 110
— drummondi, 110, 323
Fauna of Cardigan Bay, 102
Filograna, rate of growth in, 316
Filograna implexa, 644
Fishes, trematode parasites of, 466 ;
list of species examined, 497
Fissurella graeca, 109
Flabelligera (Siphonostoma), affinis, 641
Fovia affinis, 107
Fuchs, H. M. On F,, Echinus Hybrids,
464
Fucus cerenoides, 105
— serratus, 105
— vesiculosus, 105
Furcellaria fastigiata, 105
G
Gadus luscus, 340; host of Stephano-
chasmus, 477, Hemiurus, 484, Dero-
genes, 487
— merlangus, 340; host of Podocotyle,
473, Pharyngora, 478, Hemiurus,
484, 485, Lecithaster, 486, Derogenes,
487, t
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