REPORT

TO THE GOVERNMENT OF CEYLON

ON THE

PEARL OYSTER FISHERIES

OF THE

GULF OF MANAAR.

BY

W. A. HERDMAN, D.Sc, F.R.S.,

Professor of Natural History in the University of Liverpool.

WITH SUPPLEMENTARY REPORTS

UPON THE

MARINE BIOLOGY OF CEYLON

BY OTHER NATURALISTS.

PUBLISHED AT THE REQUEST OF THE

COLONIAL GOVERNMENT

BY

THE ROYAL SOCIETY.

LONDON:

1903.

/ o 7 U

iii 1

CONTENTS OF PART I.

PEAKL OYSTER REPORT.

Page

Preface v

Introduction 1

Narrative, with Outline of the Investigations, and details of the Stations where

Observations were made 17

Description of the Pearl Banks of the Gulf of Manaar 99

Observations on the Sea around Ceylon 122

Observations and Experiments on the Life-History and Habits of the Pearl

Oyster 125

SUPPLEMENTARY REPORTS.

I. — On the Sea-Bottoms and Calcretes. By Joseph Lomas, F.G.S. (One Tlate) 147

II. — The Marine Alg.e, with a Note on the Fructification of Halimeda. By

Ethel Barton (Mrs. A. Gepp) 163

III.— On the Gephyrea. By A. E. Shipley, M.A. (One Plate) 169

IV.— On the Polyplacophora. By E. R. Sykes, B.A., F.L.S. (One Plate) ... 177

V.— On the Holothurioidea. By Joseph Pearson, B.Se. (Three riates) ... 181

VI.— On the Cephalochorda. By Walter M. Tattersall, B.Sc. (One Plate). . 209

VII.— On the Copepoda. By Isaac C. Thompson, F.L.S.,and Andrew Scott, A.L.S.

(Twentv Plates) 227

a z

r v ]

PREFACE.

The plan of this work is as follows : -

An Introduction explaining briefly the past history of the Pearl Banks in the
Gulf of Manaar and the circumstances which led to my Ceylon Expedition, and the
subsequent work to which it gave rise, is followed by a section, entitled Narrative,
which deals with the course of the investigations undertaken by Mr. Hornell and
myself, given in chronological order. The observing stations where the fauna was
investigated around the Coast of < 'eylon are described in detail in the Narrative ; but
those other investigations — such as the anatomy of the Pearl Oyster, a description of
its parasitic worms, and an account of its pearl-formation — which will be dealt with
separately in special articles later on, are not treated fully in this section. After the
Narrative comes a Description of the physical condition of the pearl-oyster banks or
"paars" of the Gulf of Manaar, followed by their classification from the fisheries point
of view, and by a short discussion as to the causes of certain paars being unreliable,
and of the serious mortality of the oysters. Then comes a section dealing with the
Observations and Experiments made by Mr. Hornell and myself on the life-history
and habits of the pearl oyster, which form the basis of some of our recommendations
as to the cultivation of the oyster banks.

This general part is then followed by the Supplementary or Special Reports, which
various scientific friends have kindly undertaken to write upon their special groups or
subjects. I feel that these articles by experts add very greatly to the completeness
and value of this Report, which without them could only have given a very
imperfect account of the fauna, and flora of the Gulf of Manaar and of the other
natural conditions of existence surrounding and influencing the pearl oyster on the
various " paars."

Of these special Reports, seven are published in the present Part I. The first
of these is on the Geology of the Sea-bottom, by Mr. Joseph Lomas, F.G.S. ; it
deals with the very fundamental question of what the " paar " is, how the hard,
cemented material usually known (and marked on the charts) as " rock," which by
its presence enables the pearl oysters to live, there, comes to be formed.

The next is by Mrs. Gepp on the Alg?e collected, and this contains an account of
the previously unknown fructification of a species of Halimeda, one of the commonest
and most characteristic forms of sea- weed on the pearl banks.

[ vi ]

The remaining Reports are Zoological. Mr. A. E. Shipley's on the Gephyrea,
Mr. E. R. Sykes' on the Chitons, and Mr. J. Pearson's on the Holothurians, all
contain descriptions of interesting new forms. Mr. W. M. Tattersall's Report on
the Cephalochorda adds no new species of Amphioxus, but performs the equally useful
function of showing that some of those previously described are so closely linked
by variations that they may safely be regarded as the same. It is interesting
to find that out of the dozen well-established species of Amphioxus, no less than
seven were found in two months work round the Coast of Ceylon.

The last Report in this present Part I. — that on the Copepoda, by Mr. Isaac
Thompson and Mr. Andrew Scott — is by far the largest, and deals with a great
number of species. It is certainly surprising that we should in such a short time,
without being able to pay any special attention to the group, have come across no less
than 283 species of Copepoda, of which 76 were new to science. Mr. Thompson has
acknowledged handsomely the large share which his colleague, Mr. A. Scott, has
taken in the more laborious parts of the preparation of the Report ; but I also must
draw attention to the combined industry and skill which Mr. Scott has exhibited in
the beautiful drawings for the numerous accurate plates illustrating the new species
of Copepoda.

The next Part will be ready early in 1904, and will contain Reports upon the
Sponges, by Professor A. Dendy ; the Hydroid Zoophytes, by Miss L. R. Thornely ;
the Medusae, by Mr. E. T. Browne; the Turbellaria, by Mr. F. F. Laidlaw ; the
Polychasta, by Mr. Hornell ; the Cephalopoda, by Dr. W. E. Hoyle ; the Cumacea,
by Dr. W. T. Calman ; the Fishes, by Mr. J. Johnstone ; and the Entozoa of the
Pearl Oyster, by Mr. A. E. Shipley and Mr. Hornell.

The remaining Parts, which it is hoped will be issued during the following year,
will deal with the other groups ot animals. The reports on the Amphipoda by
Mr. A. O. Walker, on the Caprellida by Dr. Paul Mayer, on the Isopoda by the
Rev. T. R R. Stebbing, on the Ostracoda by Mr. Andrew Scott, on Sarcophytuin
and its allies by Miss E. Pratt, on the Nudibranchiata by Mr. G. P. Farran, on
the Nullipores by Mr. J. Lomas, the Polyzoa by Miss L. R. Thornely, the Crinoidea
by Mr. H. C. Chadwick, and the Alcyonaria by Professor J. Arthur Thomson, are
in progress, and some of them are far advanced. My wife is helping me with the
identification of the remaining: Echinodermata, and Professor Jeffrey Bell has
kindly undertaken to examine and describe those that seem new. Mr. A. Leicester
and Mr. W. J. Halls are engaged in examining the Molluscan shells, and will draw
up a list of all the species collected. A few other groups are still unexamined.
The final Part will contain in addition the remainder of Mr. Hornell's and my
own observations and conclusions, including the results of our experiments now in
progress, and our final recommendations as to the future management of the pearl
oyster banks.

It is pleasant to be able gratefully to acknowledge much help, both administrative

[ vii ]

and scientific. To many in Ceylon — to their Excellencies the Governor Sir West
Ridgeway and the Lieutenant-Governor Mr. E. F. im Thurn and to others — I am
indebted for much kindness and consideration which smoothed away difficulties,
expedited my work, and rendered duty a pleasure. I desire also to record my
thanks to Captain J. Donnan, then Master Attendant at Colombo and Inspector
of the Pearl Banks, and to his successor, Captain J. LEGGE, who, during the time
which I spent with them on the inspection barque " Ptangasameeporawee," spared
no trouble in trying to let me examine as satisfactorily as possible the various
banks and the other localities and conditions which I desired to investigate. I had
also the advantage of spending some days on the pearl hanks with Sir William
Twynam, who has had a long extended experience of the fisheries as Superintendent
from t862 to f896, and as Government Agent of the Northern Province.

Several men of science in Ceylon were kindly in their welcome and practical in
their help. I would specially mention Dr. A. J. Chalmers, through whose good
offices the Medical College at Colombo placed accommodation in one of their labora-
tories at the disposal of Mr. Hornell and myself; Mr. J. C. Willis, Director of the
Botanic Gardens at Peradeniya, and the late Mr. Oliver Collett, of Roselle, who has
himself written on the pearl-oyster fisheries. I was fortunate in accidentally meeting
during my first few days in Ceylon Dr. Paul and Dr. Fritz Sarasin, who had made
important biological investigations at Trincomalee ; and also Professor Alexander
Agassiz, then returning from his expedition to the Maldives, who very kindly
allowed me to ship from his steamer to mine, as they lay together in Colombo
Harbour, a reel containing 600 fathoms of steel-wire dredging rope.

I desire to record my entire satisfaction with the work done by Mr. .James Hornell,
both while I was with him and also since. I was fortunate in having such a capable
and willing assistant, and such a helpful and pleasant companion. It would have
been quite impossible for me to have got through the work that had to he done in the
very limited time at my disposal had it not been for Mr. Hornell's skilled assistance.

I am much indebted to the Staft of the Colonial Office, and to Sir Michael
Foster, K.C.B., of the Royal Society, for their interest in this investigation, for their
advice from time to time, and for the trouble they have taken in facilitating the
arrangements by which this Report will be published by the Royal Society for the
Government of Ceylon. And I need hardly say how gratefully I acknowledge the
appreciation of my labours shown by the Royal Society in assisting, in the first
instance, towards my being requested to carry out the investigation and subsequently
in undertaking the publication of the Report.

W. A. HERDMAN.

The University, Liverpool,
August, 1903,

A?

REPORT ON THE PEARL OYSTER FISHERIES
OE THE GULE OE MANAAR.

INTRODUCTION.

The celebrated "Pearl oysters" of Ceylon are found mainly on certain parts of the
wide shallow plateau which occupies the upper end of the Gulf of Manaar, off the
North-west Coast of the Island and South of Adam's Bridge. Pearl banks also exist
on the opposite Coast of India, off Tuticorin. The animal (Margaritifera vulgaris,
Schum., = Avicula fucata, Gould) is not a true oyster, but belongs to the family
Aviculid.e, and is therefore more nearly related to the Mussels {Mytilus) than to the
Oysters (Ostrea) of our British seas. One very notable character of great practical
importance, in which it differs from Ostrea, is that the Pearl oyster, like our common
Mussels, has a " byssus " or bundle of tough threads by which it can attach itself to
rocks or other foreign objects.

The Pearl Fisheries of Ceylon, India, and the Persian Gulf, yielding the highly
prized " Oriental " pearl, are of very great antiquity. They are probably the most
ancient fisheries still in existence, and seem to be carried on at the present day under
very much the same conditions as 2000 or perhaps even 3000 years ago. These
fisheries are referred to by various classical writers, and Pliny, after saying how
highly valued the pearls are at Rome, refers to Taprobane [Ceylon] as " the most
productive of pearls of all parts of the world."* Pliny also describes the coral that
abounds in the Gulf of Manaar, and mentions pearls and precious stones as the
products of Ceylon. But the Singhalese records take us to still earlier times.
According to the " Mahawanso," pearls figure in the list of native products sent as a
present from King Vijaya of Ceylon to his Indian father-in-law in about 540-
550 B.C. ; and again when, in B.C. 306, King Devanampiyatissa sent an embassy to
India the presents are said to include eight kinds of Ceylon pearls. The King's Hall
in the Brazen Palace at Anuradhapura (b.c. 161) is said to have been decorated with
native pearls. The mortar in the ruins of Polonaruwa shows the remains of the
pearl-oyster shells which were used in its manufacture — no doubt the refuse of an

* 'Pun. Nat. Hist.,' Bk. IX., chap. 54, Lemaire's Edition. I am indebted to my colleague, Professor
H. A. Strong, for kindly giving me these and other references. Athen^US and ^Elian make similar
statements. The anonymous " Periplus " of the Erythraean Sea describes a great pearl fishery at Colchi,
near Comar, in Taprobane or Ceylon, which probably refers to some part of the Gulf of Manual-.

B

2 CEYLON PEARL OYSTER REPORT

early fishery. Many other references could be given. In the eighth to eleventh
centuries, trade in the East was in the hands of the Persians and Arabs, and we find
Arab writers alluding to the pearls. We know also that they enriched the kings of
Ceylon in the days of Marco Polo (1291). One record, given by Friar Joed anus,
says that in 1330 about 8000 boats were engaged in the pearl fisheries of the Gulf of
Manaar.

Cesar Frederick, a Venetian merchant (1563), crossed from India to Chilaw
(about the middle of the West Coast of Ceylon) to be present at a pearl fishery, the
methods of which were very much as they woidd be at the present day. We are told
that the Tamil name " Salubham" (Sea-of-Gain) given to the Gulf of Manaar because
of its pearl banks, was also applied to Chilaw, which in former times was the town
nearest to the fishery. The centre of the pearl fishery is now much further north,
but the oyster " paars" still exist off Chilaw, and were fished at least thrice during the
nineteenth century, in 1803, 1815, and 1884. And so we continue to have glimpses,*
through the centuries, of this ancient and highly prized industry being carried on
with little or no change, first under the Singhalese kings of Kandy and the Tamil
kings of Jaffna, and subsequently under the successive European rulers. At the time
when RiBEYRof wrote (1685), Aripu was, as it has been since, the centre of the
northern fisheries, and from the description given, it is evident that the method of
fishing in these Portuguese times was as we see it now, even to the manning of the
divers' boats and the cessation of diving at noon. As would be expected, we have
much more definite records of the details of the fisheries during the Dutch and British
occupations than in previous times. We have a vivid description, by Martin, of a
fishery which took place off Tuticorin in 1700. Percival (1803) and Cordiner (1807)
both give excellent accounts of the early British fisheries. The last Dutch fishery
took place in 1768, and the first under English control in 1796 — and for this fishery
the arrangements were made before the surrender of Colombo.

* Here is another glimpse of the early native fisheries which I have just (August 18th, 1903) received
from Sir William Twynam of Jaffna. He says : " It is an extract from the translation of an old Tamil
work called the ' Kalveddu,' given to me some time ago by a Mr. Tilleaxobelam, employed in the
Jaffna Kachcheri" — " Vidanarayanen Cheddi and the Puravu men who fished pearls by paying tribute to
Alliyarasani, daughter of Pandiya, king of Madura, who went on a voyage, experienced bad weather
in the sea, and were driven to the shores of Lanka, where they founded Karainerkai (Karativo) and
Kutiraimalai (Kodramallai). Vidaxarayaxex Cheddi had the treasures of his ship stored there by the
Puravus, and established pearl fisheries at Kadalihilapam (Chilavaturai) and Kallachihilapam (Chilaw),
and introduced the trees which change iron into gold," &c, &c.

Sir W. Twyxam adds : " The Puravu divers referred to were afterwards converted to Roman
Catholicism by St. Fraxcis Xavier, and their descendants are, I believe, the Roman Catholic Puravu
divers who now come to our fisheries from Tuticorin and other ports in Southern India ; " and " some
large mounds of old oyster shells were pointed out to me in the neighboiu'hood of Marichchukaddi as
having been the accumulations of Queen Alliyarasaxi's fisheries."

t My copy is Le Grand's translation, "Histoire de l'lsle de Ceylan," Amsterdam, 1701; I believe it
is doubtful whether the original Portuguese of Captain Ribeyro was ever published.

INTRODUCTION, 8

A notable feature of these fisheries, under all administrations, lias been their
uncertainty and intermittent character. The Dutch records show that there were no
fisheries between 1732 and 1746, and again between 17G8 and 1796. During our
own time the supply failed — to mention only the longer, intervals — in 1820 to 1828,
in 1837 to 1854, in 1864 to 1873, and finally after five very successful fisheries in
1887 and the succeeding years, culminating in the record fishery of 1891 (when the
Government proceeds reached close upon a million of rupees), there has been no return
for the last decade. In addition to the longer intervals given above, there were many
unproductive single years or groups of two and three ; in fact there were, in all, only
36 fisheries during the nineteenth century. It will be of interest to give here
the complete list in the following table (p. 4), compiled by Mr. Hornell at the
Government Record Office in Colombo. Besides showing the marked intervals, and
the general irregularity in results, it brings out the very considerable value of the
fisheries, and is a useful indication of the relative productiveness of the principal
paars.

The intermittent character of the fisheries has been recognised by various writers
both before and since 1740, when Baron von Imhoff, then Governor, wrote in a
memorandum for his successor : — " It is now several years since the pearl banks
have fallen into a very bad state both at Manaar and Tuticorin ; this is mere chance,
and experience has shown that, on former occasions, the banks have been unpro-
ductive even for a longer period than has yet occurred at present." What was
formerly put down to "chance" has in most lines of inquiry proved susceptible of
scientific analysis and explanation, and it is reasonable to expect that, in the case of
the pearl fisheries, investigation will lead to abetter understanding of the phenomena,
and a rational treatment based on such knowledge to a greater regularity in the
results.

Writing in 1697, for the instruction of the Political Council of Jaffnapatam, the
then Commandant of that town justly remarked that " the pearl fishery is an
extraordinary source of revenue on which no reliance can be placed, as it depends on
various contingencies which may ruin the banks or spoil the oysters." The above is
quoted by both Thurston and Collett in their recent papers. Mr. Thurston's
comment is : " And this remark holds good after the lapse of two centuries." The
late Mr. Oliver Collett adds : " This statement holds good after a lapse of more
than two centuries — indeed, the periodical disappearance of oysters from certain of
the banks, sometimes for many years at a time, may be said to form one of the
jjeculiar characteristics of the Ceylon fishery. Nevertheless, since the British
occupation of the island, a sum equal to more than one million sterling lias lieen
derived from the fishery ; and the matter is therefore one of immense importance to
the Government of the Colony."*

* "Pearl Oysters and Pearl Fisheries," by 0. Collett, F.E.M.S., ' Journ. K. Asiat. Soc.,' Ceylon
Branch, vol. XVI., No. 51, 1900.

B 2

CEYLON PEARL OYSTER REPORT.

Particulars of the Pearl Fisheries held during the Nineteenth Century.
(Compiled from the Government Records.)

Year

of

fishery.

Total number of
oysters fished.

Gross Govern-
ment proceeds in
rupees.

Name and region of bank fished.

[The notes within square brackets are milled by

Mr. Hornell]

1801

•^ r

150,227

Kondatchi Paar.

1803

163,154

Chilaw Paar.

1804

770,202

Aripu

1806

412,842

u

[Cheval and Modragam paars (fide

1808

842,577

3)

y Vane's " Report " to Governor, Sir H.
Ward, February, 1863).]

Paar.

1809
1814
1815

[Particulars

not available

► as to number -

of oysters

fished.]

272,463

1,051,876
5,842

„

Chilaw

1816

9,266

Aripu"! [Cheval and Modragam paars {fide
„ J Vane).]

1820

30,410

1828

305,234

South-East Modragam Paar.

1829

382,737

North-West Cheval Paar.*

1830

222,564

South-East ,, ,,

1831

293,366

North- West „ „

1832

45,810

Off Karativu (near the Isle of Cardieu).

1833

320,896

Periya Paar Kerrai.

1835

16,058,880

403,460

33 33 33

f 6,181,537

f 58,624

Modragam Paar.

1836

J 737,105

1 10,524

Cheval Paar [Central].

] 2,974,236

] 40,158

Periya Paar Kerrai.

L 6,117,750

I 145,629

Koddai Paar [South Cheval].

1837

2,538,307

106,312

North Cheval Paar.*

1855

6,743,762

109,220

South-West Cheval Paar.

1857

32,453,053

203,633

North- West „ ,,

1858

16,484,861

241,200

33 33 33

1859

/ 3,143,402
\ 6,391,549

194,481

33 33 33

287,678

North Modragam Paar.

1860

/ 791,226
\ 2,813,271

87,269

33 33 33

279,547

South-East Modragam.

1863

11,695,794

510,178

South-East Cheval Paar.

1874

1,699,669

101,199

North- West Cheval Paar.

1877

/ 6,685,001
\ 164,719

184,591

South-East and East Cheval Paar.

4,420

North Modragam Paar.

1879

7,645,901

95,694

Kottapakku Paar (3 miles West of Cheval Paar)
[Periya Paar].

1880

35,238,972

200,152

North-West Cheval Paar.

1881

27,338,596

599,533

33 33 33

1884

636,000

17,153

Off Chilaw.

1887

/ 8,834,330

103,664

North Modragam Paar.

t 22,513,575

292,430

North-East Cheval Paar.

1888

22,052,769

804,247

Cheval Paar (whole) and both Modragams (North
and South).

1889

38,995,447

498,377 1

Muttuvaratu Paar. [Included in these figures

1890

33,677,892

313,177 y

are the proceeds of 1 day's fishing each year

1891

44,311,441

963,748 J

on Karativu Paar (200,243 oysters in 1891).]

* [We cannot attach much importance to the topography of the Cheval Paar in these early records.
The nomenclature of the regions has varied much in the past. For example, Donnan's North-East Cheval
is not that of Steiakt.]

INTRODUCTION. 5

Many reasons, some fanciful, others with more or less basis of truth, have beeD
given from time to time for the recurring- failures of the fishery ; and several
investigations, such as that of Dr. Kelaart (who unfortunately died before his work
was completed) in 1857 to 1859, and that of Mr. Holdsworth in 1865 to 1869, have
been undertaken without much practical result so far. .

In September, 1900, after a continued failure of the fishery for ten years, I was asked
by the Colonial Office (acting on the advice of the Council of the Royal Society and of
Professor Ray Lankester) to examine the records and report upon the matter, and
in the following spring I was invited by the Government to go to Ceylon at the end of
the year, with a scientific assistant, and undertake such investigation into the condition
of the pearl banks as might appear necessary. I arrived at Colombo in January, 1902,
and, as soon as a steamer could be obtained, proceeded to the Gulf of Manaar.

In April it was necessary to return to my University duties in Liverpool, but I was
fortunate in having taken out with me as my assistant Mr. James Hornell, who, it
was arranged, would remain in Ceylon for at least a year longer in order to continue
the observations and experiments Ave had started and complete our work. This
programme has been carried out, and Mr. Hornell has kept me supplied with almost
weekly reports, and with specimens requiring detailed examination.

The s.s. " Lady Havelock " was placed by the Ceylon Government at my disposal
for the work of examining into the biological conditions surrounding the pearl-oyster
banks ; and this enabled me on two successive cruises of three or four weeks each to
examine all the principal banks, and run lines of dredging and trawling and other
observations across, around, and between them, in order to ascertain the conditions
that determine an oyster " paar." Towards the end of my stay I took part in the
annual inspection of the pearl banks, by means of divers, along with the retiring
Inspector, Captain J. Donnan, C.M.G., and his successor, Captain Legge. During
that period we lived and worked on the native barque " Rangasameeporawee," and
had daily opportunity of studying the methods of the native divers and the results
they obtained.

It is evident that there are two distinct questions that may be raised — -the first as
to the abundance of the adult " oysters," and the second as to the number of pearls
in the oysters, and it was the first of these rather than the frequency of the pearls
that seemed to call for investigation, since the complaint has not been as to the
number of pearls per adult oyster, but as to the complete disappearance of the shell-fish.

Most of the pearl-oyster banks or "paars" (meaning rock or any form of hard
bottom, in distinction to " manul," which indicates loose or soft sand) are in depths of
from 5 to 10 fathoms, and occupy the wide shallow area of nearly 50 miles in length,
and extending opposite Aripu to 20 miles in breadth, which lies to the south of
Adam's Bridge. On the western edge of this area there is a steep declivity, the sea
deepening within a few miles from under 10 to over 100 fathoms; while out in the
centre of the southern part of the Gulf of Manaar, to the west of the Chilaw pearl

6 CEYLON PEARL OYSTER REPORT.

banks, depths of between 1000 and 2000 fathoms are reached. On our two cruises in
the "Lady Havelock " we made a careful examination of the ground in several places
outside the banks, to the westward, on the chance of finding beds of adult oysters
from which possibly the spat deposited on the inshore banks might be derived. No
such beds, outside the known " paars," were found ; nor are they likely to exist. The
bottom deposits in the ocean abysses to the west of Ceylon are " globigerina ooze"
and "green mud," which are entirely different in nature and origin from the coarse
terrigenous sand, often cemented into masses, and the various calcareous neritic
deposits, such as Corals and Nullipores, found in the shallow water on the banks.
The steepest part of the slope, from 10 or 20 fathoms down to about 100 fathoms or
more all along the western coast, seems in most places to have a hard bottom covered
with Alcyonaria, Sponges, deep-sea Corals, and other large encrusting and dendritic
organisms. Neither on this slope, nor in the deep water beyond the cliff, did we find
any ground suitable for the pearl oyster to live upon.

It soon became clear to us that different paars were placed under very different
physical and biological conditions, and that the sudden disappearance, or the continued
absence, of pearl oysters in different localities and at different times might be and
probably was due to very different causes. The Periya Paar, about 20 miles from
land and close to the top of the steep slope (see p. 78), is very differently situated
from the East Cheval or the Modragam paars relatively near the shore, protected to
some extent from the ocean and with shallow water all around. The pearl oyster is
the same animal all over the district, and facts of anatomy and physiology once
ascertained will hold good ; but the paars are different, each presents its own problems,
and all must be studied. In reading the reports of former superintendents and
inspectors of the pearl banks, it is possible, after acquiring some knowledge of the
physical and biological conditions of the various paars, to account for some of the
apparently mysterious disappearances of oysters and catastrophic changes in the fauna.
It is unnecessary to go over all the cases that have been recorded, but the recent
history of the Periya Paar, and the more noteworthy disasters on the Cheval and other
important paars, will be found discussed below. For a knoAvledge of the past history
of the pearl banks we are indebted mainly to the official reports of the Ceylon
Government. I would mention especially as amongst the most important contributions
to our knowledge of the subject : the reports of Dr. E. F. Kelaart in 1857 to 1859; the
" Account of the Pearl Fisheries of Ceylon," by Captain James Steuart, Ceylon, 1843 ;
H. Sullivan Thomas' " Report on the Pearl Banks and Fisheries of Tuticorin " ;
"The Pearl and Chank Fisheries of the Gulf of Manaar," by E. Thurston (Bulletin
of the Madras Museum, No. 1, 1894) ; Mr. E. W. H. Holdsworth's "Report on the
Pearl Oyster Banks," 18G7; Captain J. Donnan's successive Reports on Inspections
and Fisheries ; and finally the comprehensive and most interesting " Report on tbe
Ceylon Pearl Fisheries," drawn up in 1899 by Sir William C. Twynam, K.C.M.G.
(Colombo, 1900).

INTRODUCTION 7

There is much that we agree with in all of these previous reports. There are some
points in each on which we differ from the author. We account for the occurrence in
another way, or draw a different conclusion from the observed facts. Several of these
writers, although not strictly speaking scientific men, were accurate observers and
acute investigators who have left valuable records. Others better equipped in
scientific training have been prevented from doing more by unfavourable circumstances.
Dr. Kelaart's short reports show that he was tackling the problems in a scientific
manner, and his researches were incomplete at the time of his sudden death.*
Mr. Holdsworth's visit to Ceylon (18G5-69) was apparently made at an unfortunate
time. Mr. Oliver Collett states (' Journ. II. Asiat. Soc.,' Ceylon, Br., 1900) that
Mr. Holdsworth never had an opportunity of seeing a fishery, and according to
Sir W. Twyxam, he " did not witness an inspection of a bank with a bed of oysters
on it, young or old." Mr. Hornell and I were more fortunate, as during our cruises
in the Gulf of Manaar we found pearl oysters in all stages of growth, from the
microscopic free-swimming larvae and newly-deposited "spat" to the pearl-bearing
adults, and we have also two consecutive inspections of banks well covered with
oysters, and the successful fishery of 1903, from which to draw conclusions.
Mr. Thurston, of Madras, has also had experience of fisheries and inspections with
Captain Donnan, and has written a most interesting and valuable record containing
a great deal of incidental information as to the fauna of the Gulf of Manaar, but had
apparently not the opportunity and the implements for a more detailed survey, nor
the time for a more thorough investigation of the ovster problems.

To all our predecessors, however, we are indebted for information and for sugges-
tions which have been of value to us in our work. That work has led us into various
different lines of inquiry. Outside the larger influences, cosmic in origin, uncontrol-
lable, and wide-spread in effect, such as oceanic currents, monsoon storms, depth of
water, configuration of bottom, and shifting sands which may devastate a bank and
cause the sudden disappearance of many millions of oysters, there are, in addition,
various minor causes of failure of the fisheries, some of which we were able to
investigate. The pearl oyster has many enemies, such as Star-fishes, boring Sponges
which destroy the shell, boring Molluscs which suck out the animal, internal Proto-
zoan and Vermean parasites, and carnivorous Fishes, all of which cause some destruc-
tion, and may on occasions conspire to ruin a bed and change the prospects of
a fishery. But, in connection with such animate foes, it is necessary to bear in
mind that, from the fisheries' point of view, their influence is not wholly evil, as some
of them are closely associated with pearl production in the oyster. One enemy (a
Plectognathid fish), which doubtless devours many of the oysters, at the same time

* Soon after the fishery of 1859, during which Dr. Kelaart worked with the Swiss Naturalist,
Humbert, at Chilavaturai, he was sent to England in medical charge of General Lockyer, who was very
ill and died in the Red Sea. Dr. KELAART, who was in constant attendance on the General, died suddenly
a day or two later.

8 CEYLON PEARL OYSTER REPORT.

receives and passes on the parasite which leads to the production of pearls in others.
The loss of some individuals is in that case a toll that we very willingly pay, and no
one would advocate the extermination of that particular enemy.

In fact, while wholly at the mercy of its inanimate surroundings, such as storms
and sand, the pearl oyster can probably cope under most circumstances with its
animate environment on the paars, if not too recklessly decimated at the fisheries,
and if not exposed to some exceptional combination of adverse influences. Man has
thus afforded to him the opportunity of intervening. Although he cannot control
the monsoon or build a sea-wall around the " paar," yet without any violent attempt
to disturb the balance of Nature, or remove wholly the influence of any particular
enemy, he can compensate to some extent for the damage he himself does, and he can
help the oyster population to withstand the attacks of normal enemies and prevent
complete destruction under abnormal combinations. This he can do by giving some
attention to the breeding stock, by having a more intimate knowledge of the exact
distribution of the oysters at all ages on the ground, by attending to the dissemina-
tion and location of " spat," by thinning out in parts where there is overcrowding, or
where young are mixed with old, and by transplanting, when required, the growing
young from unsuitable ground, where from experience it is known they cannot arrive
at maturity, to more sheltered and reliable " paars."

It is clear that, in considering the conditions of existence of the oyster and the
vicissitudes of the pearl banks, we have to deal with great natural influences which
cannot be wholly removed, though they may to some extent be avoided and compen-
sated for ; and that, consequently, it is necessary to introduce large measures of
regulation and cultivation in order to increase the adult population on the ground,
have the more reliable " paars" provided more fully with successive broods of young
oysters by transplantation, and so give greater constancy to the supply and remove
the disappointing fluctuations in the fishery.

We have shown conclusively in our work the ease with which young pearl oysters
can be dredged up in quantity and transported to considerable distances, and we can
also demonstrate by our figures the advantages derived by transplantation from
overcrowded and unhealthy localities to better conditions. The young are present in
abundance, and they are probably sacrificed in millions every year. When we
examined the Periya Paar in March, 1902, we estimated the number of young pearl
oysters on the ground at not less than a hundred thousand millions ; when
Mr. Hornell returned in November they were all gone. With such numbers the
inshore paars could be kept continuously supplied with young oysters transplanted
from their precarious position on the more exposed grounds out at sea.

There is no reason for any despondency in regard to the future of the pearl
fisheries, if they are treated scientifically. The adult oysters are plentiful on some
of the paars and seem for the most part healthy and vigorous ; while young oysters
in their first year, and masses of minute spat just deposited, are very abundant in
many places. The material exists, ready for man's operations.

INTRODUCTION. 9

To the biologist two dangers are, however, evident, and, paradoxical as it may
seem, these are overcrowding and overfishing. But the superabundance and the risk
of depletion are at the opposite ends of the life-cycle, and therefore both are possible
at once on the same ground — and either is sufficient to cause locally and temporarily
a failure of the pearl-oyster fishery. What is required to obviate these two dangers
ahead and ensure more constancy in the fisheries is careful supervision of the banks
by someone who has had sufficient biological training to understand the life-problems
of the animal, and who will therefore know when to carry out simple measures of
farming, such as thinning and transplanting, and when to advise as to the regulation
of the fisheries.

In connection with cultivation and transplantation there are various points as to
structure, reproduction, life-history, growth and habits of the oyster which we had
to deal with, some of which we were able to determine on the banks, while others
have been the subject of Mr. Hornell's work since, in the little marine laboratory we
established at Galle, in the south of Ceylon.

Although Galle is at the opposite end of the island from the pearl banks of Manaar,
it is clearly the best locality in Ceylon for a marine laboratory — both for general
zoology and also for working at pearl-oyster problems. Little can be done on the
sandy exposed shores of Manaar Island or the bight of Kondatchi — the coasts opposite
the pearl banks. The fisheries take place far out at sea, from 10 to 20 miles off
shore, and it is clear that any Natural History work on the pearl banks must be
done not from the shore, but, as we did, at sea from a ship during the inspections,
and cannot be done at all during the monsoons because of the heavy sea and useless
exposed shore. At such times, the necessary laboratory work supplementing the
previous observations at sea can be carried out much more satisfactorily at Galle than
anywhere in the Gulf of Manaar.

Turning now from the health of the oyster population on the " paars " to the
subject of pearl-formation, which is evidently an unhealthy and abnormal process, we
find that in the Ceylon oyster there are several distinct causes that lead to the
production of pearls. Some pearls or pearlv excrescences on the interior of the shell
are due to the irritation caused by boring sponges and burrowing worms. Minute
grains of sand and other foreign particles gaining access to the body inside the shell,
which are popularly supposed to form the nuclei of pearls, only do so, in our experience,
under exceptional circumstances. Out of the many pearls I have decalcified, only one
contained in its centre what was undoubtedly a grain of sand ; and from Mr. Hornell's
notes taken since I left Ceylon, I truote the following passage showing that he has
had a similar experience : — "February 16th, 1(J03. 'Ear-pearls,' of two decalcified,
one from the anterior ear (No. 148) proved to have a minute quartz grain (micro-
preparation 25) as nucleus." Since then he has found one more.

It seems probable that it is only when the shell is injured, as, for example, by the
breaking off or crushing of the projecting "ears," thereby enabling some fine sand to

10 CEYLON PEARL OYSTER REPORT.

gain access to the interior, that such inorganic particles supply the irritation which
gives rise to pearl formation.

Pearls of another class are found in the muscular tissue of the animal, usually in
the levators of the foot, and in the palpar region, hut also frequently in the pallial
insertions, rarely at the insertions of the retractor and adductor muscles. These
muscle-pearls have no organic nuclei. They seem to start as minute calcareous
concretions (" calcospherules ") in the tissue, and the centre is sometimes crystalline.
They may be extraordinarily abundant. At the insertion of one levator muscle,
23 small pearls were counted with the eye, while under the microscope 170 additional
tiny spherules were found to be present.

The best pearls, however, the " cyst " or " orient " pearls, lie in the thin muscular
margin of the mantle, or in the thick white lateral part over the stomach and liver,
or even, secondarily, free in a cavity of the bod v.

Consequently, as we shall show in the section of the Report dealing with pearl-
formation, Ave can classify these pearls from the biological point of view into three
sets : — (a.) " Ampullar-pearls " which are not formed within closed epithelial sacs
like the others, but lie in pockets or ampulla? of the epidermis. The nuclei may lie
sand-grains or any other foreign particles introduced through breaking or perforation
of the shell, (b.) "Muscle-pearls"' formed around calcospherules at or near the
insertions of the muscles, (c.) '"Cyst-pearls" where concentric layers of nacre are
deposited on cysts containing parasitic worms in the connective-tissue of the mantle.

The majority of the fine pearls found in the soft tissues of the body of the Ceylon
oyster contain, in our experience, the more or less easily recognisable remains of
Platyhelminthian parasites (especially the young larva of the Cestode Tetrarhynchus),
so that the stimulation which causes eventually the formation of an " orient " pearl
is, as has been suggested by various writers in the past, due to infection by a minute
worm, which becomes encased and dies, thus justifying, in a sense, Dubois' statement
that : — " La plus belle perle n'est done, en definitive, que le brillant sarcophage d'un
ver" (Comptes Rendus Acad. Sci. Paris, 14th Oct., 1901).

To Dr. Kelaart (1857-59) belongs the honour of having first connected the
formation of pearls in the Ceylon oyster with the presence of vermean parasites. It is
true that Filippi, seven years before, in 1852, showed that the Trematode Distomum
duplicatum was the cause of pearl formation in the fresh-water Mussel Anodonta, and
Kuchenmeister (1856), Mobius (1857), and others extended the discovery to other
pearl-producing oysters, and to other parasites ; but it is possible that Kelaart
knew nothing of these papers, and that he made his discovery in regard to the Ceylon
oyster quite independently. He (and the Swiss Zoologist, Humbert, who was with
him at a pearl fishery) found " in addition to the Filaria and Circaria, three other
parasitical worms infesting the viscera and other parts of the pearl oyster. We both
agree that these worms play an important part in the formation of pearls ; and it may
yet be found possible to infect oysters in other beds with these worms, and thus

INTRODUCTION. 1 I

increase the quantity of these gems." Thus we have Kelaart, in 1859, definitely
stating the possibility, in the case of the Ceylon pearl oyster, of infecting other heds
with the larvae of the pearl-producing Platyhehninthian parasites in order to increase
the quantity of pearls.

Thurston, in 1894, confirmed Kelaart's observation, finding in the tissues and
also in the alimentary canal of the Ceylon oyster, " larvae of some platyhelminthian
(flat worm)." He figures (' Madras Mus. Bull.,' I., Plate II., fig. 1) a section showing
two of the parasites encysted between the alimentary canal and generative tuhes.
Here the matter rested so far as the Ceylon pearl oyster was concerned.

Long before, however, Garner, in 1871, had associated the production of pearls in
our common English Mussel (Mytilus edulis) with the presence of Distomid parasites;
Giard (1897) and other French writers have made similar observations in the case of
Donax and other Lamellibranchs ; and Dubois (1901) has more recently ascribed the
production of pearls in Mussels on the French coast to the presence of the larva of
Distomum mavgaritantm. H L. Jameson (1902), then followed with a more
detailed account of the relations between the jjearls in Mytilus and the Distomid
larvae, which he identifies as belonging to Distomum (Brachycoelium) somateriw
(Levinsen). Jameson's observations were made on Mussels obtained partly at
Billiers (Morbihan), a locality at which Dubois had also worked, and partly at the
Lancashire Sea-Fisheries Marine Laboratory at Piel, in the Barrow Channel. Finally,
Dubois has just published a further note (Comptes Rendus Acad. Sci. Paris,
19th Jan., 1903) in which, referring to the causation of pearls in Mytilus, he says
(p. 178) : — " En somme ce que ce dernier [Garner] avait vu en Angleterre en 1871, je
l'ai retrouve en Bretagne en 1901. Quelques jours apres mon depart de Billiers,
M. Lyster Jameson, de Londres, est venu dans la merae localite et a confirme le fait
observe par Garner et par moi." But Jameson has done rather more than that.
He has shown that it is probable (his own words are " there is hardly any doubt ")
that the parasite causing the pearl-formation in our common Mussel (not in the
Ceylon pearl oyster) is the larva of Distomum somaterice, from the eider duck and
the scoter. He also believes that the larva inhabits Tapes or the cockle as a first
host before getting into the nmssel.

We have found, as Kelaart did, that in the Ceylon pearl oyster there are several
different kinds of worms commonly occurring as parasites, and we shall, I think, be
able to show in a later section of this report that Cestodes, Trematodes, and Nematodes
may all be concerned in pearl-formation. Unlike the case of the European mussels,
however, we find that in Ceylon the most important cause is a larval Cestode of the
Tetrarhynchus form. We first found this larva in pearl-like cysts outside the liver
of pearl oysters on the Cheval Paar during the second cruise of the " Lady Havelock"
in February and March, 1902. Since then Mr. Hornell has traced a considerable
part of the life-history of this parasite, from an early free-swimming stage to a late
larval condition in the File-fishes (Batistes mitis and B. stellatus) which frequent the

q 2

12 CEYLON PEARL OYSTER REPORT.

pearl banks and prey upon the oysters. We have not yet succeeded in finding the
adult worm, but it will probably prove to infest the Hays or other large Elasmobranchs
which may devour Batistes.

We have also found the pearl-provoking Cestode larva in Pinna — where pearls are
sometimes found — but we have no reason to suppose that Pinna finds a place in the
same life-cycle with the pearl oyster. Nor do Ave think that any other Mollusc or
Invertebrate is implicated. The stages in the life-cycle, as regards environment, are
probably as follows : —

1. Free embryos in the sea ;

2. Encapsuled in the pearl oyster ;

3. Later larval stage in the File-fishes ;

4. Adult in large Elasmobranchs.

We suppose, then, that the adult Worm from the body of the Shark or Ray sets
free its numerous young embryos into the sea ; and there we pick up the history, for
amongst our Vermean embryos in the tow-net we have some caught on the Muttu-
varatu Paar, in November, 1902, which we consider to be the younger stage of our
Tetra/rhynchus larva. Such free-swimming embryos on an oyster bank will readily
gain access to the body of the oysters. They will be carried in with the current of
water, and may either pass into the alimentary canal with the microscopic food
particles or get lodged in the gills. We have found these in the gills, and have also
found very young stages in the mantle ; while later stages of larger size are common
in the liver and in the connective-tissue of the body-wall generally. In some samples
of oysters examined scarcely any individuals are free from the encysted parasites,
and in one 45 cysts were counted. In the case of oysters so infested which are
eaten by the File-fishes — and from the frequency with which we, and others, have
found the broken-up shells in the stomach there can be no doubt that these fishes do
eat the oysters — the Cestode larva? are transferred to the body of the new host ;
and Mr. Hoknell has found them in quantity in the alimentary canal and peritoneum
of specimens belonging to the two common species Batistes rnitis and B. stettatus, from
several localities. The Cestodes are now in a later stage, and are clearly recognisable
as Tetrarhynclms ; but are not yet adult and have no reproductive organs. Whether
they become mature in time in the body of the File-fish or, as we think more probable,
in a larger animal winch feeds upon that fish, such as one of the large Elasmobranchs
common in these seas, we cannot yet say ; but possibly that point may be settled
before the Report is finished.

In those oysters, on the other hand, which do not become the prey of the File-fish
the larval Cestodes have no opportunity of fulfilling their destiny as parasites, but die
and become encapsuled in the layers of pearly nacre deposited by the living tissues of
the oyster upon the source of irritation. What proportion of the parasites become
the nuclei of pearls we are not able to say, but many, we feel sure, neither complete
their life-history nor yet remain long enough encapsuled in the bodies of adult oysters

INTRODUCTION'. 13

to become pearls of value. There are many potential and incipient pearls in young
oysters which, even if transferred to the body of a fish, contain only dead larvae, and
so are lost from the parasite population ; while the death of their host prevents them
from causing pearl-formation. It is not sufficient for the oyster to be infected by the
Tetrarhynchus, it must also live, retaining its parasite, until such time as it can
produce sufficient deposit of the calcareous secretion to form a true pearl. In the
case of the Ceylon pearl oyster very little increase in size of the shell by additions to
the ventral margin takes place after an age of three and a half or at most four years
has been reached. But the shell after this period thickens greatly by the deposit of
nacreous material in its interior and especially in the neighbourhood of the hinge at
the dorsal edge. This is the time of rapid pearl-formation. The oyster's tissues are
then in the condition which leads to the secretion and deposition of limy material
either externally by additions to the thickness of the shell, or internally as successive
coats deposited upon any particle — such as a dead parasite or, it may be, a sand-
grain, a Diatom frustule, a fragment of nacre, ova, or excreta — which has given rise
to the necessary stimulation.

There is general agreement amongst those who have seen most of the Ceylon
oyster on its native banks that the animal does not, as a rule, live beyond six or seven
years. Captain Donnan's opinion is that " the oysters may be profitably fished at
the age of four years, and that they are in their prime at five years, and may be kept
till that age if circumstances will permit of it ; but if they are kept till the sixth year
they are almost certain to be found dead." From the figures he gives in his reports
it seems that the age of the oysters at fisheries where we have reliable data has been
nearly always under five years. The pearl oyster should be fished when it measures
3£ inches in diameter at right angles to the hinge line, has no soft growing edge to
the shell, and shows a deep V-shaped groove between the valves at the hinge.

Although it is not correct to say that there are no pearls in young oysters, for we
have found some of moderate size in quite small oysters, still there is no doubt that
rapid and widespread pearl-formation begins only when the animal is about three and
a half years old and has ceased to grow a thin spreading ventral margin to the shell.
During the year or eighteen months following this is the time when it is most
profitable to fish the oysters up and open them for the sake of their pearls. Although
some oysters contain more pearls than others, and some paars have on occasions been
characterized by richness in pearl-production, the Cestode parasites are apparently
very widely spread and generally distributed. All oyster communities of the proper
age contain pearls, and it would probably be impossihle to transplant young oysters
to any ground in the Gulf of Manaar where they would not become to some extent
infected by the pearl Cestode. The frequent thinning out of young oysters, and the
transporting as required from one ground to another, which we shall recommend at
the conclusion of this Report, will, however, have the effect of causing a more even
distribution of the parasites, since some oysters will he taken from more highly

14 CEYLON PEARL OYSTER REPORT.

infected ground to less, carrying with them the larvae, either free or encapsuled, and
others, again, which may have escaped infection will go to areas where they run a
greater chance of encountering the parasite. It is important to note also, in view of
experiments in other parts of the Colony, that the Tetra/rhynchus parasites are not
only widely distributed over the hanks in the Gulf of Manaar, but also at other places
on the coast of Ceylon.

Mr. Hornell* lias found Balistes with its Cestode parasite both at Trincomalee
and at Galle, and the sharks and rays also occur all round the island ; so that, in
short, there can be no doubt as to the probable infection of pearl oysters grown at
these or any other suitable localities.

The details and illustrations of the parasitic life-history outlined above, and the
figures upon which our statements in regard to the oysters are based, will be given in
the special articles further on in this Report. But even when we have figured all our
specimens, have described all that we have seen, and have shown what conclusions
may safely be drawn, we feel sure that gaps will be left, and possibly doubts remain,
which can only be filled up and finally settled by patient work extending over years,
carried on by a competent observer resident in Ceylon, and having at his disposal a
laboratory and experimental tanks. A marine biologist working at the Galle Biological
Station can scarcely fail to add further details affecting the life-history of the oyster
and the prosperity of the pearl fisheries.

During the two cruises of the " Lady Havelock," in our work on the parasites,
commensals, enemies, food, and other organisms associated with the pearl oyster, we
were brought in contact with many forms requiring identification, and some apparently
new to science. It was clearly our duty to collect all such and have them worked up
with the view of elucidating the fauna of the Gulf of Manaar and also of making any
necessary comparisons with other parts of the coast. Consecpiently, I am now able
to supplement this Report by a series of papers, written by specialists upon the
various groups of animals, which not only adds to the completeness of the pearl-
oyster work, but will also, I hope, be recognised as a welcome contribution to the
marine biology of Ceylon.

The land fauna of Ceylon is very much better known than the marine. Dr. E. F.
Kelaart published in 1852 his important work, the ' Prodromus Faunae Zeylanicre,'
dealing with the mammalia, birds and reptiles. Mr. E. L. Layard has worked at
the ornithology and conchology, and we have his papers in the ' Annals and Magazine
of Natural History.' Harvey visited Ceylon in 1852 to collect the Ccelenterates
and Crustacea. Schmarda, a few years later, wrote on the worms. In Emerson

* It is only due to my excellent .assistant, Mr. James Hornell, to state that our observations on pearl-
formation are mainly clue to him. During the comparatively limited time (under three months) that I
had on the hanks, I was mainly occupied with what seemed the more important question of the life-
conditions of the oyster, in view of the frequent depletion of particular grounds,

INTRODUCTION. 15

Tennent's ' Ceylon ' (1 859) there is a good summary of the fauna as known up to
that time, with lists which were supplied, or supplemented, or revised by HUXLEY,
Gray, Hanley, Kelaart, and others. Further papers on new animals in various
groups (many of them collected by Dr. W. C. Ondaatje) have been published from time
to time by Bowerbank, Allman, Ridley, Dendy, Bell, Carter, Nevill, and the
Sarasins. But the most notable contribution to our knowledge of the marine fauna
is Thurston's ' Notes on the Pearl and Chank Fisheries and Marine. Fauna of the
Gulf of Manaar,' published from the Government Central Museum, Madras, in 1 8'JO.
In this interesting little work Mr. E. Thurston, with the help of Professor Dendy,
Professor Jeffrey Bell, Professor Henderson, and Mr. E. A. Smith, gives con-
siderable lists of the Porifera, Ccelenterata, Echinodermata, Crustacea, Mollusca and
Pisces which he had collected during visits to Tuticorin, Rameswaram, and some parts
of the Ceylon pearl banks.

Taking a somewhat wider area — the northern part of the Indian Ocean — there are
three recent series of faunistic explorations which have some bearing on oiir work,
viz., the reports upon Dr. Anderson's collections made in the Mergui Archipelago
('Journal Linnean Soc, Zool.,' vols. XXI. and XXII.), the great series of Memoirs,
Reports, and ' Illustrations ' issued by Major Alcock, of the Calcutta Museum, as
a result of the explorations of the surveying vessel " Investigator," and lastly,
Mr. Stanley Gardiner's series dealing with ' The Fauna and Geography of the
Maldive and Laccadive Ai'chipelagoes ' (Cambridge Press). The Ceylon marine fauna
resembles that of Mergui in some respects, but differs in detail ; Dr. Alcock's
" Investigator " work has been mainly — though not wholly — in the abyssal waters
of the Indian seas ; while the Maldives are an Oceanic group, in contrast to Ceylon
which is faunistically as well as geologically a part of India. Our dredgings were
nearly all within the 100-fathom line, and were mainly in the zone of 5 to 20 fathoms.
This account of a shallow- water Continental coast fauna may till a gap and be of use
for comparison with these other recent investigations in the Indian Ocean.

The faunistic reports which will appear along with this Introduction in Part I.
will tell their own story, but it may be well to give briefly what information I can in
regard to a few of the other groups, the reports upon which may not be ready for
some months.

Professor Dendy has sent me a preliminary report upon the Sponges as follows : —
" This collection of sponges appears to be by far the most extensive that has ever
been made in Ceylon waters, and contains many species of great interest. Amongst
the siliceous sponges, the Tetractinellida are represented by at least a dozen species,
including a new Stelletta, a new Plakinastrella, and a form which will be described
as the type of a new genus under the name Dercitopsis cingalmsis. There are also a
massive Lithistid, a Placospongia, and a curious Suberites-like species which is
anchored by silky tufts of spicules in soft mud. Amongst the Monaxonids, the
Chalinidse, Ectyoninaj, and Axinellidse are the most conspicuous groups ; while of

If, CEYLON PEAKL OYSTER REPORT.

special interest from the point of view of the pearl fishery is a Clionid which burrows
in the shells of the pearl oyster. Many of the Monaxonids are characterised by a
strong development of horny fibre, and from these we pass by a natural transition to
the true horny sponges, represented by the genera Euspongia, Phyllospongia,
Hircinia, Dysidea, Spongionella and Aplysina. The Euspongia is a fairly good,

compact, resilient bath sponge and the possibility of establishing a sponge

fishery is worth consideration." Professor DENDT then gives a list of his identifi-
cations, amounting to about 60 species.

Mr. Hornell, who is reporting upon the Polychaete worms, has sent in a pre-
liminary list of over 60 species, at least four of which are new to science and will
(Mr. Hornell states) be described under the names — " Hermione ridgewayi,
Thalenassa imihumi, Phyllodoce foliosopapillata and Spiochcetopt&rus herdmani."

Mr. Isaac Thompson and Mr. Andrew Scott, who are working up the Copepoda,
state that " The collection of Copepoda is the richest and most varied series of this
group that has ever been brought from tropical seas by any expedition. The group
is represented by over 200 known species and nearly 80 new species, now being
described. Of these new species only a small number are true pelagic forms, the
remainder being littoral and semi-parasitic species, mostly associated with the pearl
oysters on the paars. Some of the pearl-oyster washings were extremely rich in
minute Crustaceans, mainly Aniphipods and Copepods. The washings from the
Muttuvaratu oysters yielded 43 species belonging to the Harpacticidse alone, besides
several species of Lichomolgidse and Ascomyzontidse, many of which are new to
science."

Mr. A. 0. Walker, who is reporting upon the Amphipoda, writes to me that it is
" The most important collection of Amphipods which has yet been made known from

the tropics It contains over 70 species, and the report will describe a large

number of new species, some of which will require new genera Many of the

forms are closely allied to British and Mediterranean species, while others again have

been described from the Australasian seas The size of the individuals is small ;

compared with those from the Arctic and Antarctic areas they are pygmies."

Mr. James Johnstone, who is writing on the fishes, reports : — " The collection
consists of 116 species belonging to 73 genera. It is very representative and contains
species belonging to 37 families. About 6 forms are still undetermined, and most of
these are probably new to science. A number of the species obtained are apparently
new to the fauna of India and Ceylon."

In other groups also, Hydroids, Polyzoa, Turbellaria, Alcyonaria, Cumacea and
Cephalopoda novelties are turning up. but the examination of these is not yet far
enough advanced to warrant more detailed announcement. In the concluding article
of the Report I hope to submit such discussion as may seem necessary of the general
characteristics and affinities of the marine fauna of Ceylon.

[ 17 1

NARRATIVE

WITH

AN OUTLINE OF THE INVESTIGATION,

AND

DETAILS OF THE STATIONS WHERE OBSERVATIONS WERE MADE.

The greater part of our observations at sea (as distinguished from the laboratory
work which came later), both on the Pearl Oysters and on the animals that are
associated with them and the conditions that surround them on the banks in the
Gulf of Manaar, can be given most conveniently in the form of a narrative of our
cruises in the s.s. " Lady Havelock " and with Captain Donnan in the inspection
boats. This narrative is written out with as little change as possible from the
diary and other note-books in which each day's work was recorded at the time.
Consequently the names in the lists of species* although, with the help of my friends
who are kindly working up the groups, they have been corrected up to the time of
writing, will naturally in some few cases require alteration, and therefore it will be
understood that, in the event of any difference in nomenclature, the " Supplementary
Reports" that follow must supersede the lists in this " Narrative." On the other
hand, this section contains the authoritative statement as to the dates, localities,
depths, and other particulars of the observing stations, and therefore forms a necessary
introduction to the Special Reports. A station, in the later sections of the work, may
be referred to briefly by its roman numeral, and the details, both as to the locality
and conditions and also as to the other organisms obtained, may be found here.

I may add, in conclusion, that my view in regard to these present lists is that
although by no means complete, they are substantially correct as far as they go, and
will serve a useful purpose in giving a general impression of the most abundant and
conspicuous, or in other ways noteworthy, organisms at each observing station. They
will also enable conclusions to be drawn as to the fauna of the " paars," and as to the
enemies and other competing organisms which may affect the life and prosperity of
the pearl oyster.

* As all these species will be treated more fully in the Special or Supplementary Reports, I have not
considered it necessary to give in these provisional lists the authorities and references. To have done so
would have added greatly to the length of the lists, with little or no compensating advantage.

D

18 CEYLON PEARL OYSTER REPORT.

Mr. Hornell and I arrived iu Ceylon on January 20th, 1902, so as to leave some
weeks free before the end of February, when we proposed to join Captain Donnan in
his annual inspection of the pearl banks. This interval I had thought essential in
order that we might perfect and test our apparatus, find out the necessary methods of
investigation, and make ourselves acquainted with the biological conditions in the
Gulf of Manaar, and with any special features in which that region differs from the
other seas around Ceylon. For the purpose of this preliminary biological survey
the Government of Ceylon placed the s.s. " Lady Havelock"* at my disposal, in the
first instance for a period not to exceed three weeks. This first cruise lasted for
twenty days (January 30th to February 19th), and was followed, for reasons given
below, by a second cruise of about four weeks in the same vessel. After that we
joined Captain Donnan on his inspection barque.

In the first cruise of the " Ladv Havelock " my objects were : —

(1.) To investigate the general biology of the seas around Ceylon, and especially

of those places where pearl oysters were said to exist.
(2.) To examine more carefully any localities that seemed to be likely spots for

uncharted pearl oyster banks.
(3.) To investigate the fauna, the bottom deposits, and the characters of the

water in the Gulf of Manaar for comparison with the conditions at

Trincomalee, Galle, and other parts of the coast.
(4.) To make experimental hauls of the fish- and the shrimp-trawls round the

coast, so as to obtain information as to the prospects of fish-trawling as

an industry in Ceylon waters.
(5.) To look into any other departments of marine biology which might be

prosecuted as useful industries.

We joined the s.s. " Lady Havelock" on the evening of Thursday, January 30th,
1902 ; and started from Colombo harbour early the following morning. The course
during this cruise is shown by the strong dotted line on the map (p. 19), and the
observing stations are marked by a cross within a circle (see also more detailed map
on p. 82). After steaming northwards for some hours the dredge was put overboard
for the first haul about 11 a.m., at 5 miles S.W. of Negombo in 12^ fathoms of water.
The rest of the day was occupied in dredging and trawling along an area about 5 miles
in length extending opposite Negombo Lake from Pamunogan at the south to
Negombo, keeping from 4| to 5^ miles off shore, in from 12 to 20 fathoms. A little
further out the sea deepens very rapidly, 50 fathoms being reached 10 miles from
land, 70 fathoms a mile further out, over 700 fathoms at about 18 miles west of
Colombo and 1000 fathoms at about 20 miles from land. My object in working along

* I ought to state that on the whole the " Lady Havelock " proved a very suitable vessel for the
purpose, and I desire to record also my sincere thanks to Captain Campbell and the officers and others
on board for the pains they took to carry out my wishes. The steamer is shown on p. 54.

NARRATIVE.

19

l-SF

fiVls^uiAE.tt JCwwa. ™ ,-..., Br

Fig. 1. Sketch-plan of route in first cruise of "Lady Havelock," January-February, 1902,

D 2

20 CEYLON PEARL OYSTER REPORT.

the shelf within the 20-fathom line oft* Negombo was (1) to get a fair sample of the
conditions and the fauna for comparison with the pearl bank region off Aripu further
north and (2) to explore the ground and the water, as we did wherever possible, for
any stages young or old of the pearl oyster.

There is a record of an old pearl oyster bed, the " Muttu-Parawuttu Paar" lying
about 4 miles W. of Negombo in 9 fathoms. No oysters have, however, been found
there I believe for many years. We did not find any trace of this paar, but may have
been just outside it ; next day however we came upon large quantities of young pearl
oysters about 7 miles further to the north. Half-a-dozen hauls of the dredge, two
hauls of the 25-foot beam- trawl, with a 7-inch fish-net, and four surface gatherings
with the silk tow-net were taken on this first day, off Negombo ; and these, although
recorded separately at the time, may now be united as one locality : —

STATION I. — Five miles west and south-west of Negombo; 12 to 20 fathoms;
bottom coarse yellow sand with a few dead shells; temperature of sea, 77 '5° F. ;
dredged and trawled. Amongst the animals were : —

Various sponges ;

Diphasia mutulata, Lytocarpus (? n. sp.), Campanidaria juncea, and some
Plumularian Zoophytes, Caryophyllia sp. and Heteropsammia michelini (with
commensal Gephyrea), Gorgonacea (Spongodes, &c.) ;

Leptoplana sp. and another Turbellarian, and Aspidosiphon corallicola, Filograna sp.,
Hyalincecia sp., Terebella sp., Acholoe sp. (commensal with Astvopecten), Hesione sp.,
Ophelia sp. and other Annelids ;

Crisia sp. and other Polyzoa ;

Echinus and Temnopleurids (sev. spp.), Salmacis bicolor and S. sulcata, Lovenia
elongata, Clypeaster humilis, Echinodiscus auritxis;

Thyone sacellus, Holothuria atra, H. tenuissima and allied species of "trepang"
(up to 16 inches long), Pectinura intermedia and other Ophiuroids, Astvopecten
hemprichii, Luidia maculata, Antedon sp. ;

Lepas sp., Hippolyte sp. (with Bopyrid) and other Macrura, Neptunus sp., Calappa
sp., Elxdia sp., and other Brachyura ;

Acanthochitest penicillatus, Styliola acicula, Teredo sp. (in wood), Area (sev. spp.),
Venus lamarcki, Cardium rugosum, Pinna bicolor, Pectunculus sp., Dentalium
octagonum, Murex tenuispina and M. haustellum, Oliva Candida, Turbo margari-
taeeus, Conus marmot at us, Natica sp., Harpa conoidalis, Umbrella sp., Pleuro-
phyllidia sp., Melibe fimbriata and Sepia sp.

Molgula sp., and some colonies of a snowy white Leptoclinum which grows over the
coarse quartz sand and cements the grains together.

The Tow-net gatherings contained : —

Trichodesmium erythrmim (in quantity), Diatoms, Ceratium tripos and some
Foraminifera ; Sagitta sp., Salpa demoeratica-mucronata , and Oikopleura sp. ;

NARRATIVE. 21

Copepoda — many, including a conspicuous blue form Centropages violaceus, and
also Oithona siinihs, Euterpe gracilis, Ectinosoma atlanticum, Temora discaudata
and T. stylifera, Eucalanus subtenuis, Calanus vulgaris, Calanopia elliptien,
CoryccBits speciosus and C. venustus.

[Note. — In coming across the Indian Ocean to Ceylon we used silk tow-nets day and night to strain
the organisms from the sea-water running from the tap in one of the bath rooms. In two of these
gatherings I obtained the pelagic Amphioxus (Branchiostoma pelagicum, Giinther). One specimen was
taken in a coarse net on January 16th, to the south-east of Sokotra, about halfway between Perim and
the Maldives ; and five others were found in a finer net on January 20th, after passing Minikoi Atoll,
and therefore between the Maldives (where this species was found by Stanley Gardiner) and Ceylon.

Amongst other interesting or novel forms found on the way to Ceylon were : — a new species of
Centropages (rather widely distributed), Miracia minor (taken near Sokotra, previously known from
Gulf of Guinea), Mecynocera claim (common), Scolecithrix chelifer (Red Sea, the only known locality),
Pseudodiaptomus salinus (Suez Canal and Red Sea, males found for the first time), Anymone spherica (in
Suez Canal), Acartia dubia (Suez Canal, only known previously from Gulf of Guinea), Pseudocyclops
oblusalus and Canuella perplexa (both European forms, now found in Suez Canal). These will be discussed
fully by Mr. Isaac Thompson and Mr. Andrew Scott in their Report on the Copepoda — see below, p. 227.]

On Saturday, February 1st, we dredged and trawled at various localities between
Negombo and Chilaw, covering an extent of about 23 miles. The distance was
generally from 4 to 5 miles off land, and the depth varied from 8 to 14 fathoms.

This day's hauls can be grouped into two localities; the first (Station II.) from
opposite Ooluwitti to oft" Mararilla, half-way from Negombo to Chilaw, and the second
(Station III.) off Chilaw ; we dredged and trawled at both, as follows : —

STATION II. — From 7 to 14 miles north of Negombo, 5 miles offshore ; 8 to 9 fathoms ;
bottom coarse yellow sand, shells, stones, and small coral ; temperature of sea,
77"5° F., specific gravity, T023. Two hauls of fish -trawl and several of dredge.

Pachychalina sp., Acanthella carteri, Hircinia sp., and Siphonochalina sp. (pale
lilac, with large oscula occupied by small colourless Alpheus) ;

Masses of living corals (up to 20 X 14 X 6 inches), many solitary corals, mainly
Stephanoseris rousseaui and Heteropsammia michelini, small scarlet Actinians ;

Linens sp., Aspidosiphon corallicola (in the solitary corals), Lumbrinereids,
Hesione sp., Axiothea tubes (in masses), Serpula actinoceros, S. quadricomis,
Sabellaria bicornis, and many Polyzoa ;

Antedon variipinna and another species (many), Luidea rnacidata, Clypeaster
humilis, Laganum depression and Echinodiscus auritus, Salmacis dussumieri, scarlet
Ophiuroids, and Phyllophorus cebuensis ;

Leucothoe spinicarpa and other small Amphipods and Isopods not yet determined,
some Macrura, Galathea sp. (black and white), and Pilnmnus vespertilio ;

Young pearl oysters (in quantity), Avicula vexillum, Conns marmoreus and a few
other common shells, Philine sp., Aplysia sp. ;

22 CEYLON PEARL OYSTER REPORT.

Pseudorhombus arsms, and some sea-snakes (see p. 65).

On the second haul, which was 5 miles off Ooluwitti, at a depth of 8j fathoms,
the trawl came up with the heam broken, but contained some large masses of coral
and great quantities of young pearl oysters, measuring from \ to 1^ (mostly 1) inch
across. There is evidently at this point some hard bottom with coral growing on it,
and with many broken lumps of coral and rounded masses of nullipore, from the size
of a walnut to that of an orange — constituting in fact a " paar " upon which young-
pearl oysters are living. The oysters we got are in their first season, and probably
ranged from one to three months in age. On the sand outside this hard patch we
brought up quantities of the filamentous green weed (Hypnea, Cladopliora, and
Gracilaria spp.), which we found afterwards on the south part of the Cheval Paar,
covered with the newly deposited "spat" of the pearl oyster.

STATION III.— Off Chilaw, 2j to 4 miles off shore; 9 to 14 fathoms; bottom coarse
sand and small corals; temperature of sea, 7775° F. ; specific gravity, r023 ;
one haul of fish-trawl and several of dredge.

Large numbers of Heteropsammia michelini (with Gephyreans).

Antedon sp., Pentaceros lincki and P. nodosus, Echinanthus rosacea*;

Aspidosiphon corallicola, Pagurids and other crabs, Neptunus pelagicus ;

Mitra militaris, Turbinella rapa (the sacred chank), Philine sp. ;

Leptoelinum (2 species).

We were now in the region of the Chilaw Paars, which consist of (1) one large
bank running north and south for about 9 miles, at a distance of from 7 to 8 miles
from shore, with a depth of 8 to 10 fathoms; (2) a group of two small paars lying
north-east of the large Chilaw Paar, at from 5 to 6 miles off-shore ; and (3) four
small paars nearer the shore opposite Karkopani, about 4 miles north of Chilaw.
These small paars are little hard patches, so-called " rock," on the general sandy
expanse. The rough bottom varies greatly in depth, the extremes on these inner
paars off Karkopani being 6 to 16 fathoms. Outside the outer large Chilaw Paar
the depth increases rapidly, and at one place, in less than a mile, we pass from 10 to
over 100 fathoms, at about 10 miles off shore.

On February 2nd we first had several hauls of the dredge (the trawl could not
be used because of the very irregular hard bottom) amongst the inner paars off
Karkopani, then trawled in the more even sandy ground (9 to 11 fathoms) between
the inner and the outer paars, and finally had a couple of hauls of the dredge along
the outer edge of the outer paar at depths of from 10 fathoms outwards to about 30
(the dredge dropped off the bottom finally on the steep slope about the 100-fathom
line). I bave placed the dredging off Karkopani as Station IV., and have united
the trawling and dred<nne; further out as Station V. ; but Stations III., IV., and V.,
explored on the two days spent off Chilaw, do not differ much and may be regarded
as one region. (Also Station LXIX., see chart of route and stations on p. 82.)

NARRATIVE. 23

STATION IV. — Opposite Karkopani, from 1 to 3 miles off-shore; depth 6 to 9
fathoms; bottom coarse yellow saud with dead shells, nullipores and corals;
temperature of sea (7 a.m.), 77 "8° F. ; specific gravity, 1'023. Several hauls of
dredge.

Orbit olites complanata and Tlcterosicijina depressa (forming a good deal of the
sand) ;

Axinella donnani, Acanthella carteri, and a black leathery sponge ;

Solenocaulon sp., Sarcoph ytum ehrenbergi, Goniastrcea sp. (green), Turbinaria
cinerascens, Heteropsammia michelini (with Gephyreans) ;

Luidea maculata, Asterina cepheus, Astropecten hemprichii, Echinus sp. (small,
flat), Echinolampas oviformis, Maretia planulata, C/ypeaster humilis, Love n ia
elongata, Thymic fusus, var. papuensis (two), Holothuria atra;

Gephyreans (yellowish, burrowing in pearl oyster shell), Cirratulids (deep red),
Sabellaria bicornis, Serpulids (on pearl oysters), Trophonia sp. (?), and Polyzoa ;

Caprellids, Pagurids, Portunids, Galappa sp. and other crabs ;

Acanthochites penicillatus, and, in addition to pearl oysters, molluscs belonging to
the following genera : — Avicula, Solen, Pecten, Mactra, Cardium, Area, Pectunculus,
Strombus (S. succinctus), CyprcBa, Conus, Terebra;

Branchiostoma belcheri, Asymmetron cingalense, and a Solenette (Cynoglossus sp. ?).

STATION V. — On both edges of upper end of Chilaw Paar, from 5 to 10 miles oft*
shore; depth, 9 to 11 fathoms and upwards; bottom coarse yellow sand, with
many Orbitolites and Heterostegina inside the paar, outside broken coral,
Halimeda and Nullipores ; temperature of sea (2 p.m.), 79° F. ; specific gravity
1*023. One haul of trawl and several of dredge.

Tetractinellid sponges, Siphonochalina sp., Acanthella carteri, Dictyocylindrus
(scarlet, massive), Pachychalina multiformis var. manaarensis, Madrepora (two
species), Pocillopora sp., Turbinaria cinerascens, Plexaura indica;

Pentaceros lincki and a white Spatangoid ;

Pectinaria sp., Euphrosyne sp., Polynoe (spiny) ; Polyzoa (various) ;

Melita, obtusata, Elasmopus subcarinatus, Leucothoe spinicarpa and another (? n.
sp.), some interesting new Caprellids, Galathea elegans and some other Decapods ;

Pectunculus sp., Pinna bicolor, and many young pearl oysters; Leptoclinum sp.

The Tow-net gatherings during the day (February 2) contained Sagitta, Appen-
dicularia, Nauplei, Plutei, Larval Polychaetes, the veliger stage of Mollusca, eighteen
species of Copepoda and the conspicuous blue Centropages violaceus.

Having now obtained what we considered fair samples of the bottom, and of the
animals associated with the pearl oysters, on the paars off Chilaw, and of the ground
between the paars, we steamed for some distance north along the shores of Kalpentyn
Island, and anchored for the night about 1 mile off " St. Anna's Church," near the
Etaly ferry across Putlam Lake (one of the succession of great inland seas, " gobbs"

24 CEYLON PEARL OYSTER REPORT.

or lagoons, that extend up this coast of Ceylon) to Putlani Fort. The tow-net was
left out all night, and on being hauled at 5 A.M. was found to contain many large
Stomatopod larvas in various Erichthus stages, and some Lucifers, various other larvae
as on the previous day and a few Copepods (Labidocera acuta, L. kroyeri, and
Calanus vulgaris). Another haul taken at the same spot from 8 to 9.30 a.m. contained
a mass of minute plant-life. Navicula and other diatoms, Pediastnim, and many
small larvse of worms and Copepod nauplei ; also small adult Copepods (Ectinosoma
rosea and E. atlanticuni and Oithona similis).

A third haul at 11.30 a.m. had swarms of crab zoea and some Foraminifera
(Plauorbidina), also the blue Copepoda (Centre-pages violaeeus), Pontella securifer,
several species of Labidocera, including a large new species, also a greenish-blue
larval Squilla. This last haul was taken further north, over Muttuvaratu Paar,
but the difference in these successive gatherings is probably due to some extent to
the time of day and to tidal currents carrying streams of plankton past the ship.

My intention was now to examine the neighbourhood of the celebrated Muttu-
varatu Paar lying off the middle of Karativo Island, and perhaps one of the most
important of the pearl oyster grounds after the Cheval and Modragam paars. It
afforded profitable fisheries in 1889, 1890, and 1891.

We commenced dredging at 11.30 a.m. and spent the rest of the day in making a
traverse from east to west across the paar and into the deep water lying outside
it. The first five hauls were all in the neighbourhood of the paar and may be
considered as one locality (Station VI.), and several hauls were then taken at two
spots (Stations VII. and VIII.) further out, the first at 45 to 50 fathoms and the
second at 90 to 100 fathoms. This was one of the localities where we examined the
ground outside the known paars, down to the 100-fathom line, with the view of
ascertaining whether there was any evidence in support of the statement which had
sometimes been made in the past, that there were probably unknown beds of pearl
oysters further out and in deeper water from which spat was produced for the supply
of the inshore paars. No evidence was found.

STATION VI. — Across Muttuvaratu Paar, 4 to 6 miles west of the centre of
Karativo Island ; depth 6 to 9 fathoms ; bottom sand with hard patches of
"rock" at intervals; temperature of sea at noon 78° F., at 4 p.m. 79° F. ;
specific gravity 1'023. Five hauls of dredge.
Spongionella nigra, I'hyllospongia holdsworthi, Axinella doyinaia ;
Zoanthns sp. and lilac Actinians, Madrepora cytharea, Montipora sp., Porites sp.,
Astrseids (two species), Turbinaria cinerascens, Sctrcophytum ehrenbergi, Plexaura
indica (with Cirripede galls), and other Alcyonaria ;
Sabettaria bicornis and Serpula sp. ;

Echinaster purpureus, Opliiocnemis marmorata, Cucumaria turbinata ;
Pearl oysters, Modiolaria sp., Modiola sp., Doris sp. ;

_.)

NARRATIVE.

Botryllus sp. and Leptoclinunt sp. ;

Small olive-green Wrasse with white tail (Pomacenirus bankanensis).

STATION VII.— Further out, from G to 7 miles off shore; depth 45-50 fathoms;
dredged.

Large masses of coral overgrown with Chama foliata ; Chromodoms sp. ;

Squilla (small — many — in cavities of the coral) ;

Sabella sp., Eunice sp., Lepidonotus acantholepis and HarmotJioc imbricata, all
evidently associated with the coral.

STATION VIII— Still further out. 71 to Si miles off shore : depth 90-100 fathoms ;
dredged.

Gorgonia miniacea, Juncella juncea, Antipctthes sp. (black, fan-shaped), Cyatho-
helia (!) and another allied form ;

Galaihea sp. (scarlet), Lambrus sp., Arcania sp. and other crabs ;

Some species of Nassa and Murex and some small Octopods.

We now steamed further north to the region of the great Cheval paars, lying off
the bight of Kondatchy, and started dredging at 8 A.M. on Tuesday, February 4th,
along the southern edge of the West Cheval Paar. My object was, after seeing the
condition of the ground on the Cheval Paar, to make a line of dredgings across the
Cheval and the region outside it to the Periya Paar.

STATION IX.— On south-west corner of West Cheval Paar, about 12 miles from
land ; depth 7 fathoms ; bottom fine quartz gravel, nullipore concretions, and
many dead young pearl oyster shells ; temperature of sea, 78° F., specific
gravity, 1'023 ; dredged.

Axinella lubulata, Clathria indica (on oyster shells);

ftertularia distans and other Hydroids ;

Actinometra jmrvicirra and another species, Pentaceros linchi, Clypeasler humilis,
Iloloth uria tenuissima ;

Physcosoma scolops (in Axinella tubulata, with commensal tubicolous Oligochastes),
Serpida actinoceros, Armandia sp. ;

Pearl oysters, along with " Suran" and " Oorie " ;

Branehiostoma belcheri (several).

In this haul young pearl oysters about ^ inch to 1 inch in size were obtained
in quantity, but the majority were dead ; of 200 picked up at random only 20 were
living. A large number of small boring Gastropods (belonging to the genera
Purpura, Nassa, Sistrum, &c, and known collectively to the natives as "Oorie")
were present. They ranged from § inch to J inch long and were very active, and
no doubt contribute to the mortality of the oysters. There were also present
considerable numbers of the small mussel, Modioli barbata, known to the natives as

E

•2<; CEYLOX PEAEL OYSTER REPORT.

" Suran," which form irregular nodular masses of gravel and oysters hound together
hy a network of byssal threads spun hy the mussel. A number of the shells of the
Suran as well as of the pearl oysters were perforated by the boring Gastropods.

The next eight hauls (Stations X. to XVII., some of them really representing
more than one descent of the dredge) form a series taken from east to west from
inside the Cheval to outside the Periya Paar.

STATION X. — One mile to east of East Cheval Paar ; depth 5f fathoms ; bottom
quartz sand and dead shells ; no oysters ; dredged.
Sclerophytum polydactylum, Suberogorgia suberosa, and other Alcyonaria ;
Luidea macidata, Astropecten hemprichii, Pectinura gorgonia ;
Cirratulus sp., Acholoe sp. (on Astropecten), Lumbrinereids ;
Caprellids (many), Hyastenus sp. (covered with Hydrnids) ;
Eburria sp., Turrit dla sp., Philine sp. ;

Sty da sp. (with red apertures), Molgula (many), Leptoclinum sp. ;
Dragonet (Platycephalus punctatus).

STATION XI. — On East Cheval Paar ; depth 6 fathoms ; bottom, sand ; dredged.

Hircinia dathrata (with Acasta spongitis) ;

Camjjanidaria juncea, Plumularia setacea (? n. sp.), Idia pristina and MonoMachys
didi otoma ;

Centrosiphon herdmani, n. gen. and sp. (Shipley), Physcosoma asser ;

Clypeaster humilis and Ediinodiscus auritus, Lovenia eloagata and Echinolampas
oviformis, Synapta sp. (?) ;

Lepidonotus carinidatus, Harmothoe imbricata, Filograna sp., Retepora sp.

Species of Conus, Cyprcea, and Oliva ;

Branchiostoma calif or niense, Asymmetron (Heteropleuron) cultellum.

STATION XII. — Between East and West Chevals ; 6 fathoms ; bottom fine sand and
much green Algse (Hypnea, Cbidophora, Gracilaria spp.), no oysters ; dredged.

Laganum depressum, Clypeaster humilis, and Ediinodiscus auritus;

Sphmroma sp., Mcera rubromaculatct, Elasmopus subcarinatus, Caprellids and other
Amphipods ; Philine sp.

STATION XIII.— On West Cheval Paar ; depth 6 fathoms ; bottom old worn coral
fragments and dead shells.
The haul contained nothing conspicuous except a number of large pearl oysters and
a few small ones. The larger ones measured 2|- to 3j inches across. There were also
a few dead oysters, four of which had the valves honeycombed by the boring sponge
Clione ', and some of the coral fragments contained the Gephyrean Aspidosiphoit
steenstrupia. The corals were mainly Porites and Astrreids.

NARRATIVE. 27

STATION XIV.— About 2 miles west of West Cheval Paar; depth 8 fathoms;
bottom sand with many young and a few old pearl oysters; dredged.

Astropecten hemprichii, Linckia laevigata, Echinaster purpureus, Clypeaster humilis;

CJdceia ceylonica, Serpula actinoceros, S. quadricornis, Ophelia sp. ;

Margaritifera vulgaris (in quantity) and Natica sp.

Leptoclinum sp. (green).

In this haul three dozen large and about 15,000 healthy young pearl oysters were
taken. The young were placed in batches in our deck tanks and kept under
observation.

STATION XV.— On Periya Paar, 18 miles off shore ; depth 9 fathoms ; bottom sand ;
many young oysters ; dredged.

Petrosia testudinaria and other large sponges, Reniera sp. (green, with oysters
attached), Axinella tuhulata (with commensal worm) and A. donnani, Phyllospongia
holdsworthi;

Favia sp. (large, green), Adamsia sp. (small, grey, proliferating) ;

Echinostrephus molare, Ophioinaza cacaotica, Peciinura intermedia;

Eunice cirrobranchiata (?), Armandia sp., Sabella phatotamia, Serpula quadricornis,
Leucodora sp., Pagurids (brilliant orange) ;

Pearl oysters, " Suran," " Oorie," Murex anguliferus (the elephant chank), and
species of Conns.

The small oysters of this haul were many of them dead. They measured from ^ to
over |- inch in size, and quite a number of the dead valves were perforated by boring
Gastropods. Out of a small handful taken at random, 17 oysters were living and
45 were dead, 7 of which were perforated, and along with them were 3 " Suran " and
2 " Oorie" (§ inch long).

STATION XVI.— On Periya Paar, about a mile further north ; depth 9 fathoms ;
bottom sand, with nullipores, dead coral and shells, with great quantities of
young living pearl oysters ; dredged.

Orbitolites (very large), Heterostegina depressa, Amphistegina lessonii ;

Isodictya sp. (green) ;

Paraplanocera aurora ;

Pearl oysters and Solarium sp., Turbo sp., and young Octopods (a new species
with branched processes on the body) ;

A ntennarius mummifer.

The numerous pearl oysters in this haul were nearly all young ones, from § inch to
yf inch in size, and apparently in a healthy condition.

STATION XVII. — Outside western edge of Periya Paar; 11 fathoms; bottom same as
last haul ; small pearl oysters very abundant ; dredged.
Ciocalypta sp., and other sponges ;

28 CEYLON PEARL OYSTER REPORT.

Holothuria atra, Ophiocnemis marmorata ;

Phyllodocc foliosopapillata n. sp. (Horxell), Lepidonotus trissochcetus, L. carinu-
lalus, Panthalis mdanonotus (in sandy gelatinous tubes) ;

"Suran," Avicula sp. ;

Asymmetron (lletcropleuron) cingalense (12 specimens).

Of the numerous small pearl oysters in this haul rather more than half (on the
average 11 to 9) were dead, many of them entangled with " Suran."

Several hauls of the tow-net were made during the day (February 4), and amongst
the most abundant organisms noticed were : — -

Diatoms (vast quantities), Ceratium, Peridinium, and spherical gelatinous Alga?.

Mitraria, Nauplei, and other larvae ;

Copepods (29 species), Oiihona similis, Calanus minor, Pseudodiaptomus aurivillit,
Pontellopsis strenua and P. perspicax, Calanopia elliptica, Labidocera acuta, Tortanus
forcipatus, Centropagcs sp. (new to science) ;

Sal pa democratica-mucronata.

The blue Copepods and Salpa were mainly in the later more westerly hauls
(18 miles from shore), and the Diatoms and Alga? in the earlier hauls on the Cheval
paars. A gathering taken during "the night gave some large Sagitta, a few small
Medusa?, some Amphipods and Nebalia.

Having now made a preliminary examination of the pearl-hank regions in the Gulf
of Manaar and obtained some samples, I decided to visit various other localities round
the island to which attention has been directed either by the literature of the
subject or by information obtained since landing in Ceylon. We therefore made
our way next through the Pamban Pass, between Rameswaram Island and the
mainland of India, into Palk Bay, which lies north of Adam's Bridge (see map of
route, p. 19).

On February 5th, while lying at the southern end of the passage, waiting for the
pilot, the sea-temperature at 10.30 a.m. was 77 "5° F.. and the specific gravity was
T0205. A tow-net gathering taken here contained a new species of Centropages,
with a remarkable dorsal spine, and a new species of Labidocera.

On February 6th, at the north end of the pass, opposite the village of Pamban, at
7 a.m., the sea-temperature was 76° F. and the specific gravity only 1 "0 1 'J ; at 7 p.m.
in the middle of Palk Bay the sea-temperature was 78° F. and the specific gravity
I '021. This day was spent trawling and dredging in Palk Bay, a wide shallow area
lying between Adam's Bridge and the northern end of Ceylon, and partly enclosed by
the chain of islands extending southwards from Jaffna, with, for the most part, a
muddy bottom at a depth of from 6 to 8 fathoms. Parts of it near the islands are much-
blocked, as we found later, by luxuriant coral growths, but the centre presents a large
open expanse with a uniform soft bottom suitable for trawling. Pearl oysters are said
to bs found in a few feet of water in some places round the shore, but there are no
fisheries, and our object here was not to look for "paars" but i'or fish, as I had under-

NAKEATIVE. 29

taken to report upon any grounds suitable for the use of the European fish- or
shrimp-trawls if occasion presented itself.

We first took a haul of the dredge to ascertain the bottom and, finding it soft and
muddy, put over the large fish-trawl about 7 miles north-east of Rameswaram, at a
depth of 7 fathoms, and towed for G or 7 miles in a south-easterly direction parallel
with the length of the island. A second haul of the trawl was made from the point
reached onwards in the same direction to a point due north of about the centre of
Adam's Bridge and distant about 9 miles. The third haul was from that point
onwards in a more easterly direction towards the Island of Manaar. The beam of the
trawl came up damaged on this occasion and had to be shortened by about a foot.
The fourth and last haul of the day was taken rather further out than the last and
further east, off the western end of Manaar Island, and about !) miles off shore. Here
the beam again broke and required to be repaired, but the contents of the net were
saved. The hauls varied from 4 to 7 miles in length and the trawl was generally
down nearly two hours. The bottom remained the same and the depth was very
uniform. In the middle of the stretch it deepened to 8 fathoms, but towards the end
we ran into 7 again. As these hauls were practically continuous, and as the
conditions and the results were so much alike in ail cases, I think it best to consider
the whole day's work as one locality (Station XVIII.), lying to the north of Adam's
Bridge and contrasting markedly with the much more irregular bottoms and hard
ground lying to the south in the Gulf of Manaar.

STATION XVIII. — South-west part of Palk Bay, off Rameswaram Island and Adam's
Bridge, from 7 to 9 miles off shore ; depth 7 to 8 fathoms ; bottom fine soft
bluish-grey mud containing casts of various Molluscan shells ; four hauls of
fish -trawl and one haul of dredge : —

Holothurian (white and minutely spinous, apparently a new species of Synapta),
Salmacis bicolor ;

Nemertine (large red, like Valencia splendida, and also two slender white ones),
(?) Terebella tubes, (?) Sabella tubes, Chlceia ceylonica, Gastrolepidia clavigera, other
Polychaetes ;

Anilocra sp., Squilla sp., Macrurids (sev.), Portunids and other crabs :

Eburna sp., Turbinetta rapa, Fusus turriada, Nassaria acuminata, Mitra
pyvamidalis, Cerithium citrinum, Murex tenuispina (many), Natica (with egg-coil),
Mya sp., Pinna fumata, Lithodomus sp., Dentalium (up t<> 3^ inches long),
Cephalopod eggs ;

Balanoglossus (probably Glandiceps Jutekii).

The Fish* caught on this occasion were : —

" Cat-fish" (Arius venosus, Cuv. and Val.) ;

" John Dory" {Gazza equal oaf ovmis, Riujp., and Equala splendens, Cuv.). Up to

* I give the English rough equivalent as entered at the time in the diary, followed by the scientific
name as determined since by Mr. J. JOHNSTONE, who will report upon the fishes in detail.

30 CEYLON PEARL OYSTER REPORT.

6 inches long. Even those of 3 inches long showed the ovaries mature. Intestine
dark green in colour and contents consisted entirely of a large Navicula-like Diatom ;

" Arnoglossus" (Psettodus erumei, Bl.) ;

" Sand-eels" (several small Tccaiolabrus sp. and another) ;

" Bass" (Scicena maculata, Bl. Schn.) ;

" Soles" (Cynoglossus spp.) ;

" Pomfret" or " Pamplette" (Stromateus sinensis, Euphr.) ;

" Plaice" (Pseudo rhombus arsius) ;

" Mackerel" (Caranx hippos, Linn., probably = Scomber heberi, Bennett).

During the day (February 6) several tow-net gatherings were taken. In the
morning (8 A.M.) there was a large amount of material, chiefly Alima and other
Crustacean larvae, also some large Sagitta, a few Mysids and large Copepoda
(Labidocera acuta and Pontella tenuiremis). In the afternoon there were fewer
animals, but an enormous amount of Trichodesmium erythrceum, which in places
formed a dirty reddish scum on the surface.

This same locality (Station XVIII.) was also visited later on (March 14th) and
trawled over again with much the same results. [Station XIX. is in the northern
part of Pal k Bay, and was worked on March 16th — see below, p. 83, and map, p. 82.]

Palk Bay measures about 34 miles from north to south (roughly from off Jaffna to
the middle of Manaar Island) and 40 miles from east to west along the south (say
from Manaar to Rameswaram), and is 20 miles across further up between Delft
Island and Devil's Point. It is about 1 00 miles round the coast from Rameswaram
to Punkudutiva, and another 30 across the entrance ; and must contain over 900
square miles. Of this area probably two-thirds is trawlable ground, with an even
muddy bottom at a depth of 7 fathoms nearly all over, while outside is the still
wider area of similar character known as Palk Strait, between Ceylon and the
Tanjore Coast. Our hauls in both the north and the south parts of Palk Bay
showed that there are plenty of fish, and apparently this shallow area serves as a very
valuable " nursery" for young fishes.

A great part of the Ceylon coast would certainly be very difficult to fish according
to European methods, and in some cases it is practically impossible to trawl because
of the coral reefs and other obstacles ; but Palk Bay is one of a few areas where
there is a considerable extent of ground suitable for trawling, and containing an
abundant fish fauna.

The " Lady Havelock" now steamed round the north end of the island from Palk
Bay to Trincomalee. After the Gulf of Manaar 1 regarded Trincomalee as the most
important place 1 had to visit and report upon — in the first place, because of
Dr. Kelaart's experiments and observations in regard to pearl oyster cultivation
there some fifty years ago, and secondly, because pearl oysters are known still to
live in some parts of the inner bay, where they are collected and eaten by the natives
and where pearls are occasionally found. About the time we arrived in Ceylon

NARRATIVE.

31

some letters appeared in the Colombo newspapers on the matter, and a Mr. J. B.
Colomb, resident in Trincomalee, sent to me one or more specimens of oysters from
which pearls had been obtained.

On February 7th, at 7 a.m.. we were off Muletivo Shoals, on the north-east coast,
and the sea-temperature was 77° F. and the specific gravity 1'021 ; at 7.30 p.m. that
night in Trincomalee inner bay the temperature of the sea was 78 "3° F. and the
specific gravity 1*022. About 2 p.m. we reached Back Bay (fig. 2), outside Trin-
comalee, and took a haul of the dredge (Station XX.) in order to see whether the

qttia Sand

Fig. 2. Sketch-plan of the bays round Trincomalee, showing Stations XX. to XXXI.

ground was suitable for pearl oysters. The bottom was hard and bore a mixed fauna,
but no oysters were found. The tow-net contained a number of Copepoda, including
Oithona minuta and a new Labidocera, close to L. kroyeri.

STATION XX.— North part of Back Bay, Trincomalee; depth 11-13 fathoms;
bottom hard ; dredged. Amongst the animals obtained were : —
Anemones attached to Ftisus tuberculatus, Heterocyathus aequicostatus, and
Heteropsammia michelini (with Gephyreans) ;

32 CEYLON PEARL oYKTEK REPORT.

Stellaster sp. (many), Astropecten liempricliii and A. eury acanthus, Ophiocnemis
marmorata and other Oplhnroids, Cucumaria imbvicata (several) ;

Aspidosiphon corallicola, &c. ;

Cardium rugoaum, Fusus tuberculatus, Cerithium citrinum, Tudicla spirillus,
Philine sp.

We divided up the days devoted to work in the neighbourhood of Trincomalee so
as to examine as much as possible of the fauna of this extensive and complicated
region (see fig. 2). About twelve bays were explored either with the steamer or the
small boats, and we also managed to do some collecting along the shore. The general
arrangement was : —

( hi February 7th, Back Bay :
,, ,, 8th, Back Bay, Dutch Bay, and off Foul Point;

,, ,, 9th, at anchor, shore-collecting, and investigating the pearl oysters ;

,, ,, LOth, dredging from the boats in the creeks of the inner bay ;

,, ,, 11th, Tamblegam Bay.

On February 8th, at 7 a.m., the sea-temperature in the inner bay was 77'5° F., and
at 8 a.m., in Back Bay, was 78° F., the specific gravity at both localities being 1'021.
We started dredging at 8 A.M., in the southern part of Back Bay (Station XXL), one
of the localities where Dr. Kelaart is said to have deposited pearl oysters in 1857,
and where we were told the native fishermen occasionally found them.

STATION XXI.— In Back Bay, North of Fort Frederick; depth 8-12 fathoms;
bottom firm sand, in places some mud; several hauls of dredge, but no traces
of pearl oysters. Amongst the animals obtained were : —

Adamsia ? (on Chank shell), Virgularia juncea, Pteroeides esperi;

Laganumdeprcssum, Thyone fusca, n. sp. (Pearson), Cucumaria imbricata, various
Ophiuroids and small Asterids (mainly young StclJasters) ;

Carinella sp., Terebella and other worm tubes ;

Portunids (small), Ebalia sp. and other crabs ;

Turbinella rapa, Strombus succinctus. and species of Comix, Cerithium, Dentalium,
and Cardium ;

Psammaplidium sp. and Lcptoclinum (sev. spp.).

We then tried Dutch Bay (Station XXII. ), to the South of Fort Frederick, with
similar results, a hard bottom with an abundant general fauna, but no pearl oysters.

STATION XXII. — Across mouth of Dutch Bay from Fort Frederick to Dutch Point ;
depth 13 fathoms; bottom dead coral, shells, and Nullipores ; dredged.
Fungia sp, , Dendrophyllia sp., Heteropsammia michdini (with Gephyrea), Sarco-
phytum sp., and other Alcyonaria ;

NARRATIVE. 33

Linckia diplax, Astropecten zebra (?), and various Ophiuroids ;

Halsydna sp., Serpula actinoceros ;

Pontonia sp., Lambrus sp., and other Decapods ;

Molgula sp., and a few common Molluscs.

As we had heard that pearl oysters had been found " off the Suami Hock," Fort
Frederick, between Dutch Bay and Back Bay, I considered it necessary to examine
the ground further in close to the rocks where the steamer could not be taken. So
we engaged a pilot's large boat with a native Tindal and crew and took with us
Mr. J. B. Colomb, from Trincomalee, who professed to know where specimens had
been obtained by native fishermen. We took haul after haul of the dredge close in
along the northern edge of the Suami Bock (Station XXIII. ), beginning abreast of
the detached rock oft1 the point of Fort Frederick peninsula and working along
parallel with the shore past the old Dutch boat-jetty. We were all the time on the
ground indicated by Mr. Colomb and the native pilot, and obtained good hauls, but
nowhere was there any trace of pearl oysters — not even fragments of dead shells.

STATION XXIII.— Close to Suami Bock, Back Bay ; depth 4£ to 8 fathoms, mostly
between 5 and 6 fathoms; bottom sand, shells, and in places stones and corals.
Half-a-dozen hauls of the dredge.

Caryopliyllia sp. and other small corals, Rhipitlogorgia sp. and other Alcyonaria ;

Spatangoid, Antedon sp., Ophiuroids, Holothuria atra, Linckia multiforis ;

Melita obtusata, Ebalia, and other small crabs ;

Malleus vulgaris, Octopus sp.

We then steamed across the mouth of " Great Bay," in order to try a haul of the
trawl in the open off Foul Point. Unfortunately the bottom proved unsuitable, the
trawl eventually caught fast, and, before the strain could be relieved, the bridle
parted and the wire rope came in, bringing with it the ring of the bridle (in which
was entangled a beautiful dendritic Antipatharian colony) and leaving the trawl at
the bottom. We then dredged over the same ground in the hope of entangling the
dredge in some part of the trawl, but in vain. We may unite these hauls as :—

STATION XXIV.— Two and a-half to three miles north of Foul Point; depth
ranging from 46 to 24 fathoms ; bottom hard and rough — probably rock.

Sponges (many), various corals ;

Various Gorgonacea, including Juncella juncea and Solcuocaulou tortuoswm ;
Aiitipatlics sp., and Cirrliipathcs spiralis;

Antedon rcynaudi (on Gorgonids), various Ophrarids (on Gorgonids) ;

Bonellia pumicea (in Coral) ;

Melita obtusata and other Amphipods ;

Ischnochiton ferreus, n. sp. (Sykes).

We landed with a party of our Maldivian lascars at Shell Bay, near Foul Point, to

F

Si CEYLON PEARL OYSTER REPORT.

examine and collect on the beach. Many "calling-crabs" (Gelasimus) were seen,
and a large quantity of molluscan shells was obtained — a species of Bulla was
especially common. Only one specimen of pearl oyster (dead, but having the valves
still attached) was found, and a closely allied species of Avicula with a longer wing
was also taken. Amongst the other shells obtained here, and at other places round
Trincomalee, were such typical Indian forms as : —

Pecten plica, Pinna bicolor, P. fumata, P. chemnitzii, and P. zebuensis, Modiola
tulipa, Psammobia amethystus, Cardium asiaticum, Ostrea hyotis, Vulsella rugosa,
Avicida vexiUum, Area decussate/,, Chama foliata, Malleus vulgaris, Placuna placenta ,
Ricinula arachnoides, Rotella vestiaria, Trochus niloticus, Margarita acuminata,
Phasianella lineolata, Fasciolaria trapezium, Pyrula Jicus, Fusus tuberculatum,
Murex haustellum, M. tenuispina, Eburna zeylanica, Triton lotorium, T. pilearis,
T. galliuago, T. tripus, Xenopltora calculifera, Solarium perspectivum, Strombus
succinctus, S. sibbaldii and S. canarium, Cassis glauca, C. canaliculata, Dolium
maculatum, D. olearium, Conus tessellatus, C. terminus, C. miles, C. betulinus,
C striatus, Oliva maura, 0. gibbosa, O. ispidula, 0. elegans, O. torsans, O. Candida,
Cyprcea arabica, C. lynx, C. moneta, C. ocellata, C. errones, C. caput- serpentis,
C. coffea, C. tigris, C. mauritiana, C asellus, Natica mammillata, Pterocera scorpius,
Harpa conoidalis, II. ventricosa, Eburna ceylonica, Pyrazus palustris, Turritella
duplicata, T. attenuata, Telcscopnum fuscum, Terebra tigrina, Turbinella spirillus,
Bulla ampulla and Spirula peronii.

Two hauls of the dredge were now taken nearer Foul Point (Station XXV.) in
much shallower water and on smoother but less interesting ground.

STATION XXV. — Three-quarters of a mile to a mile west-north-west of Foul Point ;
depth 8 fathoms ; bottom firm, Orbitolites sand and Nullipores ; dredged.

Orbitolites complanata, Heterostegina dep)ressa and other Foraminifera ;

Fungia dental" ; Antedon sp. ;

Hyalinacia sp. (numerous), Sigalion sp. ; various crabs ; Molgula sp. ;

Ampliio£Us'i:~ (two, young), Saurida nebulosco, Leptocephalus and a small Sole.

Several tow-xet gatherings had been taken during the day (February 8th), but
they contained comparatively little except Trichodcsmium crythreeum, which was
present in great abundance, some Euclavta sp., Labidocera hroyeri, Euterpe acutifrons,
and many young Copepods.

The following day (Sunday) we lay at anchor in Trincomalee harbour, and employed
the time in very necessary examination, jjreservation, and packing of specimens, and
unpacking of stores, and writing up of notes. We also did some shore-collecting and
obtained local evidence in regard to the occurrence of the pearl oysters at Trincomalee.
Mr. Colomb had brought on board, for our inspection, a number of the empty shells
of oysters which had been picked up by the natives in shallow water between Powder

* Specimens apparently nut kept, so species not certain.

NARRATIVE. 35

Island and Victoria Wharf. They had been gathered alive in January and used for
food. We measured 240 valves, which ranged in size from 2'2 to 5 centims. in
diameter. The average size was 4 centims. So these, as well as all we collected
ourselves, were of small size.

Trincomalee is an admirable collecting ground for molluscan shells; some of the
numerous beaches in the neighbourhood have fine specimens cast up — for which natives
are constantly on the look out — and there are Moormen in the town who are expert
dealers, and have large stocks. I examined several of these collections, with the
object of looking for large specimens of the pearl oyster ; but although nearly every
little box or basket of shells, made up for sale to passengers on the steamers, contains
a couple of valves of pearl oysters, these are all of small size, and none were seen
comparable with those from the Gulf of Manaar.

Some detached valves, about 1^ inches long, were found on the shore close to the
Cutch Company's bungalow. Near the same spot were some heaps of a large
Mytilus, having masses of quartz gravel entangled in the byssus, and also quantities
of Pinna — evidently all used for food. Many small rock oysters were seen adherent
to boulders and masonry at various points round the bay (see fig. :i).

The sea-temperature this day (February 9th) in the harbour was 78'2° F. at 8 a.m.,
and 78° F. at 7 p.m. The specific gravity at both times was 11)2 1.

Next day (February 10th) at the same place, at 7 a.m., the temperature was 78° F.,
and at 7 p.m. was 78 '8° F. At both times the specific gravity was 1*020. There had
been some rain in the night. The temperature in our various tanks in the ship, in
which we kept animals under observation, now began to vary considerably. In the
ship's baths the water was 80° F., while some of our wooden tanks were only at
75'5° F. February 10th was devoted to dredging in the various smaller bays or coves
which open off the so-called " harbour " (fig. 2) or inner bay of Trincomalee. We may
regard each bay as one station, although several hauls of the dredge may have been
taken in it.

STATION XXVI— Outer part of Yard Cove, between Plantain Point and Middle
Point and inwards to the "narrows"; depth 2 to 8 fathoms; bottom coarse
sand and gravel with thin layer of mud on surface. Several hauls of dredge.

Much black branched and pale lilac Renierid sponges ;

Astropecten sp. ; Synapta striata (lilac and white, in branches of sponge masses) ;

Sipunculids, Lumbrinereids ;

Various Ebalid, Portunid and Eurynomid crabs ;

Strombus succinctus (many), Neritina sp. (common) ; Molgula sp.

STATION XXVII.— Entrance and middle of ( !od Bay ; depth 4 to 6^ fathoms ; bottom
muddy sand ; several hauls of dredge.
Gelliodes carnosa, Halichondria sp., Clathria sp. ;

Thyone calcarea, n. sp., Holothuria temiissima, H. atra, and H. marmorata;

F 2

36 CEYLON PEAEL OYSTER REPORT.

Polynoe sp., Ghjcera decipiens ;
Strombus sp. and other common Molluscs ;
Amphioxus (ajjparently undetermined).

STATION XXVIII.— Middle, of China Bay; depth 7 to 14 fathoms; bottom black
sandy mud ; several hauls of dredge.
Holothuria gallensis, n. sp. (Pearson), Astropecten hemprichii, A. polyaoanthus ;
Ghjcera (small pink), and some long calcareous worm tubes, &c.

STATION XXIX. — French Pass ; depth 4 to 7 fathoms ; bottom mud with a few
stones ; several hauls of dredge.
Holothuria marmorata (the large yellow, spotted brown trepang) ;
Some Molluscs, Annelids and Polyzoa (including Adeonct sp.).

STATION XXX.— Nicholson's Cove; depth 4|~10 fathoms; bottom muddy sand;
dredged.

Euspongia officinalis ; and a Cubomedusa ;

Holothuria atra (the large black and pink trepang) ;

Hyalincecia sp. ;

Strombus succinctus, S. sibbaldii, and a few other common Molluscs.

The shoal at the inner end of Nicholson's Cove has a hard bottom with occasional
boulders, which are covered with small rock oysters up to 3j inches long (average
size 2 inches). It is one of the few spots at Trincomalee which would probably do
well for the pearl oyster.

Mr. Hornell and I managed to land also during this day at various points to
examine the shore and the shallow-water fauna — which was very important here
because of the remarkable fact that the pearl oyster is found living naturally between
tide-marks.

At the far end of Nicholson's Cove we found one or two dead sjjecimens of the
commercial sponge, and we also dredged a piece which proved to be Euspongia
officinalis. This showed that it evidently grows in the neighbourhood, and we have
since found it in quantity. In the mangrove swamps which fringe the ends of this
and some other coves there are great numbers of small land crabs (Ocypoda
macrocera) and also of the semi-terrestrial fish Periophthahnus, some of which we
caught, with some difficulty. We tried to keep the Periophthahnus alive in our
tanks on the ship, but the little fish persisted in coining out of the water and getting
on deck. They scrambled up the vertical wooden sides by taking advantage of the
angles at the corners of the tanks.

We waded over all the shallower parts of the harbour where Dr. Kelaart
had investigated the pearl oysters in 1857, and where Mr. Colomb reported
that oysters are now found by the natives. The chief place is between Powder
Island and the shore near the wharf (fig. 2). Here the bottom is hard gravel with

NARRATIVE.

37

some rock in situ and large boulders. Rock oysters and a species of Area are
abundant on tbe rock and boulders (fig. 3) and on pieces of* wreck, also quantities oi

Fig. 3. Rock oysters (Osbrea sp.) i;i Trincomalee harbour at low tide.

Mytilus of good size were living on and in the gravel anchored by the byssus.
Attached to these and to other objects were many pearl oysters of smallish size.
Samples of these were taken alive to our laboratory on board ship. In the sand around
the island Pinna bicolor lives in abundance, of large size, almost wholly buried, the tips
of the valves just projecting beyond the level of the sand, and the byssus deep below,
generally having some larger objects such as small stones and dead shells attached to it.
On the shores of Powder Island we also found Periophthalmus kohlrcuteri and thick-
bodied land-crabs, and also a shore-crab with a long crenated front margin between
the eyes ; a Nentina and a Littorina were common, and we found a large rough
Nudibranch, yellow and grey speckled, under a stone.

I obtained a native dug-out canoe and went across the bay towards Orr's Hill to
see some natives diving for trepang in a few fathoms of water. The species were
Holothuria marmorata (spotted yellow and brown forms) and H. atra (black, with
a lighter pinkish under-surface). The divers were said to obtain 75 cents (one shilling)
per 100 for these.

We next examined a reef of rock and coral lying off the Cutcb Co.'s bungalow.
Here by wading, or by using the water-glass in the deeper parts, we saw living
coral in quantity (chiefly Porites and Astrseids), much sponge, and many fair-sized
pearl oysters attached either to mussels as before or to the rock by their byssus,
They appear to extend sporadically across the sand from Powder Island to Orr's Hill.
Pinna bicolor and P. fumata were present in the sand and gravel around, and an
Ostrea on the rocks. We caught a small yellow Ostro.cion amongst the pearl oysters.
Undoubtedly this spot, and the ground round Powder Island and the shoal at end
of Nicholson's Cove are the best spots in Trincomalee for the cultivation of the pearl

38 CEYLON PEARL OYSTER REPORT.

oyster. The bottom is suitable, and apparently the animals live naturally and grow
fairly well there. Most of the other bays and creeks we examined are useless because
of the large amount of mud present. We deposited in the harbour a number of living-
pearl oysters brought round from the Gulf of Manaar. They were enclosed in a wire
cage anchored and buoyed at a spot duly recorded outside Little Powder Island.
Mr. Hornell will examine these on his next visit to Trincomalee.

Of the pearl oysters collected at Powder Island and on the reef oft* the ditch Co.'s
bungalow, 33 were at once examined as to the sexual condition — 18 were males,
11 females, and 4 quite immature. The males ranged in size from 1-^ inch to
2\ inches, and the females from 1^ inch to 2^ inches. Some of these were ripe,
and we fertilised some ova with the spermatozoa.

On the following afternoon we examined the shore in the other direction (south),
between the wharf and York Island, by means of small boat and wading. Here we
came again upon rock oysters, small land crabs and a large Ligia, also living corals
and Pinna. The bottom round York Island and towards the rocks near the Admiral's
house is hard and seems suitable for pearl oyster cultivation ; we found several dead
pearl oyster valves on the shores of the island.

On the whole Trincomalee presents several distinct advantages as a locality in
which experiments in pearl oyster cultivation might be carried on : but on the other
hand it has several disadvantageous characters. As to the first, the pearl oyster
already lives there in a healthy state, and sometimes, at least, produces pearls.
Secondly, the locality is protected from the monsoons and sheltered in all weathers, so
that work and observations could lie carried on at all times of the year. Thirdly,
there are several places in the bay where the bottom is hard and seems suitable for
the attachment of pearl oysters. The greater part of the area is, however, very
muddy ; it is said that large quantities of clay are washed down by the rains, the
specific gravity of the water is rather lower than that usually found in the Gulf of
Manaar, and, so far as our observations show, the plankton or microscopic life floating
in the water is relatively small in amount and that will probably mean poor feeding
for the larger animals. The pearl oysters we found at Trincomalee struck us as looking
rather dwarfed or poorly nourished, and they were found to be sexually mature at a
much smaller size than was the case with those of the Gulf of Manaar. Hence while
experiments might be carried out at Trincomalee when impossible elsewhere because
of weather, the conditions of water and food are probably not so favourable as in the
Gulf of Manaar and would probably not lead to such active growth and shell
(including pearl) formation.

The greater part of our last day (February 11th) at Trincomalee was devoted to
the examination of Lake Tamblegam, an enormous shallow sea-water area opening by
a narrow entrance from Great Bay. The sea-temperature at 7.20 a.m. in Great Bay,
oft' the entrance to Tamblegam, was 78° F. and the specific gravity 1*0160; at 9 A.M.
in Lake Tamblegam the temperature was 80° F. and the specific gravity 1*0145; at

NARRATIVE.

39

7 P.M. in Trincomalee harbour the temperature was 78° F. and the specific gravity
L-0202. The entrance to Tamblegam is obstructed by a long curved sand-spit on the
south and a number of scattered rocks and reefs on the north, so the steamer was
unable to get within a mile or more of the channel. From there we sailed in the
ship's gig with a strong easterly wind which carried us into the lake in fine style,
lint gave considerable trouble when we tried to return in the afternoon. The passage
was found to be too narrow and too much obstructed to beat out against the wind,
and when we lowered the sails and started to row out through the breakers now
coining in from Great Bay, first one and then a second of the six oars broke, followed
by the snapping off of one of the brass rowlocks at a critical moment. The boat then
made way very slowly, dodging where possible behind the rocks at Noddi Tevu, and
so eventually got through the worst of the sea and out of the narrow channels into
the open bay.

Lake Tamblegam has long been known as the scene of a fishery of the flat thin
"window-shell" oyster, Placuna placenta, a remarkable form (see fig. 4) in which

Fig. 4. Placuna placenta, from Lake TamMegam; half natural size. A, outside of shell; B, inside;

C, edge view.

an exceedingly thin body is contained — or compressed — between two almost flat
discoidal valves of considerable size (up to (J inches across) which can easily by scraping
off the outside be rendered at least translucent to light, and are said to be used as
window-panes in Chinese huts and at Goa. Pearls are not unfrequently found in
these window-shell oysters and profitable fisheries have been held in the past at
Tamblegam. The pearls are mostly small and these are said to be exported to India
to be calcined to make chunam for betel-chewing. We did not on this visit see any
living specimens of Placuna, although Mr. Hornell has seen them since ; but the
great gleaming piles of dead shells seen at various points along the shore (fig. 5)
were evidence of the enormous numbers that had been taken in the former fisheries,
and especially at the last fishery fifteen years ago, when the stock in the lake seems
to have been nearly cleared out. There were also in places heaps of piled up rock-

40

CEYLON PEARL OYSTER REPORT.

oysters (Ostrea sp.), some of very large size. These, as well as a large species
of Venus and a mauve Psammobia, are used as food by the natives. The whole lake,
measuring more than 20 miles round, is very shallow, most of it being under a fathom
in depth. On the southern coast we found there was not enough water to row round
near the shore in the ship's boat, so we crossed to near Corrinjahvat in the north

Fig. 5. Heaps of window-shell oysters (Placuna placenta) on the shores of Lake Tamblegam, from

the last fishery.

where great piles of Placuna valves line the shore. We took a few hauls of the
dredge here in about 1 fathom of water, and also dredged across the mouth of the
inlet known as Narche Coudar (fig. 2, p. 31). In both spots (the whole of Lake
Tamblegam may be regarded as Station XXXI.) the bottom was mud with a little
sand, and there were few animals : — some worm tubes, a few small Medusae, a flat
Clypeastroid and some Pagurids in Gastropod shells.

The bad weather, and a knowledge that the difficulty we should have in getting
out would be increased with delay, prevented our spending longer time in Tamblegam
Lake, and unfortunately fully as many days as could be spared had now been given
to the Trincomalee district. But I arranged with Mr. Horxell that after my
departure from Ceylon he should take an early opportunity of visiting Trincomalee
and Tamblegam by land, and by making use of native fishermen and divers from the
shore, satisfy himself as to any of the matters which we had left undecided.

The main points on which I wished him to get further evidence were : —

(1.) Whether the water of the harbour differed much in muddiness and salinity
at other seasons ;

NARRATIVE. 1 I

(2.) Whether the commercial sponge which we had found lived in any easily
accessible spot in sufficient quantity to constitute a fishery :

(3.) Whether the window-shell oyster was still present in abundance in any part
of Lake Tamblegam.

Mr. Horxell carried out tbese instructions in October. L902, when lie spent a
week at Trincomalee and made a thorough examination of Tamblegam Lake. He
was successful in settling, I think, all the points referred to him. He found that the
specific gravity of the water varied about TO 19, at a temperature of 84° F. to 'J0° F.
But he was told this had been an unusually dry season at Trincomalee.

With the help of native divers he found the bath sponge living in quantity, of good
size and suitable form, in a few feet of wrater along the shores of Plantain Point and in
Yard Cove. I have examined the specimens he sent to Liverpool and have shown them
to Professor Arthur Dexdy, our leading specialist on the subject. Professor Dendy
determines them as Euspongia officinalis, the common bath sponge, and describes the
samples we had before us as being a fairly good, compact, resilient bath sponge, but
containing a certain amount of grit in the form of broken foreign spicules in the
primary fibres. He adds : " The possibility of establishing a sponge-fishery is worth
consideration.''

Mr. Horxell examined a number of pearl oysters from round Powder Island and
elsewhere in the harbour. They had increased in size since our visit in Februarv
but were not so numerous.

In his visit to Tamblegam (Station XXXI.) he found the temperature of the water
varied from 87° F. to 90° F. and the specific gravity from I/O 16 to TO 19. Amongst
the animals he obtained were : —

Tetractinellid sponge (a curious Suberitid species which lives anchored in the soft
mud by silky tufts of spicules, and the presence of which is regarded by the divers as
an indication of Placuna) ;

Sagartia sp. (on Cassis) and a (?) Cerianthid (in tube) ;

Various crabs, including a burrowing form with scarlet antennae :

Venus sp. (collected as food by natives near mouth of Kinnia River), Psammobia sp.
(mauve, eaten by natives), Placuna placenta, Trochoid shell (abundant). Ostrea sp.
(rock oyster).

We left Trincomalee on the night of February 11th, for Galle, and the following
morning at 10 a.m., when 30 miles south of Batticalloa, found the sea-temperature
to be 78° F. and the specific gravity T0215. We took a haul of the dredge
(Station XXXII.) some distance further on, off the south-east of the island.

STATION XXXII.— Five miles East of Arugam Bay; depth 17 fathoms; bottom fine
sand.
Solenocaulon tortuosum and other Alcyonaria ;
Astropecten (two species);

G

42 CEYLON PEARL OYSTER REPORT.

Serpula actinoceros ;
Ampelisca macrocephala, Pagurids ;
Cassis glauca and a few other Molluscan shells.

A tow-net gathering taken at the same time yielded 26 species of Copepoda along
with Trichodcsmium erythrceum.

Another haul of the dredge was taken further on at

STATION XXXIII. — Halfway from Arugam to Little Basses, about 4 miles from
land ; depth 18 fathoms ; bottom dead shells and Nullipore.

Axinellid sponge (large, orange, branching, gorgonid-like form, which is probably a
new genus) ;

Solitary corals, Plexaura indica and some other Gorgonacea ;

Rhinobrissus pyramidalis (?), various Ophiuroids ;

Ampelisca macrocephala, and other Amphipoda.

We reached Welligam (or Belligama) Bay, near to Dondra Head, the most
southerly point of the island, in the early morning of February 13th. One of the
points I had to determine during this preliminary survey of the marine biology of the
Ceylon coast was the most suitable spot for a small marine laboratory in which
Mr. Hornell could continue our work at the pearl oysters during the monsoon after
I left. All naturalists know of Professor Haeckel' s visit to Ceylon in the winter of
1881-2, and of how he carried on shore and pelagic work for some months at the
southern end of the island, and especially at Welligam (the " Bella-Gemma"' of the
enthusiastic German professor), where he found congenial quarters, ideal natives and
an interesting fauna. His happiness in his general surroundings is reflected in his
glowing description of the bay as a zoological paradise. Hearing that I was going to
Ceylon, Haeckel kindly wrote pressing " Bella-Gemma " upon my attention as an
ideal spot for a biological station. He also very fairly mentioned Trincomalee as a
place where his friends Dr. Paul and Dr. Fritz Sarasin had worked but which he
did not himself know. Welligam looked charming on land, but seemed to us to have
a poor bottom fauna compared with either Galle or Trincomalee. Haeckel however
worked mainly, if not wholly, on the surface animals collected witli the tow-net ; and
these no doubt, so far as the oceanic forms are concerned, are much the same as at
Galle.

While the " Lady Havelock" lay at anchor in Welligam, we went off in the boat
and had seven hauls of the dredge scattered fairly over the bay so as to adequately
sample the ground. As all parts seemed alike in character and fauna I propose to
unite them as —

STATION XXXIV. — Welligam Bay, various parts; depths 2 to 7 fathoms; bottom
shell-sand and a little mud ; sea-temperature at 7 a.m. 7 7 "8° F., specific gravity
1-0225 ; dredged.
Orbitolites complanata, Polytremu miniaceiim, and small sponges;

NARRATIVE. 4::

Hydractinia sp., small Gorgonids ;

Echinodiscus auritus, Lovenia dongata, Antedon sp. ;

Glycera lancadivce, Serpula sp., and some other small worms, Lepralid Polyzoa ;

Ampelisca brevicomis, some Pagurids and small crabs ;
Turritetta duplicate/,, Philine sp. and many dead mollnscan shells ;

Molgula sp. (small), Amaroucium sp. and Amphioxus* (2).

We landed at the south-eastern corner of the bay, near the fishing village of
Mirissa, which seemed the most promising part — zoologically — as it may possibly be
a little sheltered from the south-west monsoon, and examined a good deal of the beach
and of the shallow water near from the boat. There are red cliffs of coarse gneiss at
the extremities of the bay, which no doubt give it its chart name " Red Bay."
Pagurids of several species, some inhabiting the shells of Helix and other land
Molluscs, were very common on the upper part of the beach and in the cocoa-nut
plantations beyond. A crowd of several dozen were found congregated upon a small
heap of dung evidently feeding. Others were sheltering in numbers about the
roots of the trees. A Pterocera shell (Ft. lambis) was found on the beach, small
Limpets were abundant on the red rocks at the point, and many long-spined purple
Echinids (Stomopneustes variolaris) were in hollows in the rock pools, and also under
the sea in cavities and crevices of the rock. Living Corals were seen from the boat
in the shallow water just inside the point.

On the whole this was a disappointing bay. There is no place where experiments
in the cultivation of the pearl oyster could be carried on. There is no ground where
we could expect to find the animal, or where it would probably be able to live. The
bay is open to the full force of the south-west monsoon, and this would introduce
difficulties in collecting and other biological work during a great part of the year.
It is unsuitable both for the general work of a biological station and also for the
special purposes of the pearl oyster investigation.

We went on the same night to Galle — the last of the localities round the coast
which I had noted for comparison with the Gulf of Manaar.

Altogether five days were spent on this occasion investigating Galle and its
surroundings, and another visit of several days was paid later on, in March.

February 14th was spent in dredging in the bay, and shore-collecting;

February 1 5th in dredging near Watering Point, and shore-work ;

February 16th in examining the Coral reef and the lagoon (see fig. 6) ;

February 17th in dredging off entrance to Galle Bay and neighbourhood ;

February 18th in dredging and trawling in deeper water outside Galle and
onwards.

On February 14th we had several hauls of the dredge in the entrance to the bay,
between the points, which may be united as —

Probably BranrMosfnma lanrtolafum, but the specimens have apparently not been preserved.

G 2

44

CEYLON PEARL OYSTER REPORI'.

STATION XXXV. — Entrance to Galle Harbour, near the black buoys and Mata-Mada
Rocks ; depth 4^ to 7 fathoms ; bottom coarse sand ; sea-temperature, at
G.30 a.m. 78'5C F., at 9.30 a.m. 79° F. ; specific gravity 1*023 ; dredged.
Calcareous sponge (Clathrina sp.), Hymeniacidon sp. ;
Diphasia mutulata;
Glycerol sp., Leanira sp. ;

Ampelisca brevicornis, Hippa asiatica, and several Brachyura ;
Pteropods, and some shells of the genera Cucullcea, Qstrea, Anomia, Tumtdla :
Branchiostoma lanceolatum.

Fig. G. Sketch chart of Galle Bay, showing Stations XXXV. to XLL, the Coral reef. Lagoon,
position of the Biological Station (B.S.), &e.

Four hauls of the dredge taken in the afternoon and evening near Gihbet Island
and the Kata Rocks may be united as —

STATION XXXVI— Galle Harbour, off Gibbet Island and Glosenburg from Kata
Rocks inwards: depth 2 to 4f fathoms; bottom tine sand and mud ; dredged.
Some sponges, and Hydractinia sp. ;

NARRATIVE. 45

Nereis foliosa, Glycera sp., Sevpula quadricornis ;

Ebalia sp. and other small crabs ;

Shells of Dentalium octagonum, Eburna canaliculata, and other Molluscs;

Leptoclinum sp., and Branchiostoma {Dolichorliynchus) indicus.

Halobates was seen on the surface in quantities during the afternoon, and a tow-
net gathering taken in the evening, after dark (about '.» p.m.), contained Corycceus
obtusus, Labidocera puvo and L. hroyeri, Pseudodiaptomus serricaudatus, and a new
species of Centropages. On the following evening, after dark, we again got very
much the same series of Copepoda.*

In the little bay between Gibbet Island and Glosenburg (tig. 7) the bottom is fine
sand, ripple-marked, and with occasional boulders. The entrance is bounded by a
chain of submerged rocks covered with Alga; and Corals. The bottom and sides art'
not unsuitable as a locality for biological experiments when in the condition in which
we saw them, but the situation is exposed, and there is probably a heavy surf rolling
into the little bay during the south-west monsoon. We examined this bay and
also the creek behind Gibbet Island with some care, as the locality had occurred to
us as a possible position for the biological laboratory, and moreover Haeckel in his
book on Ceylon had strongly recommended it for the purpose (see below, pp. 4G, 47).

On February 15th we examined the south-eastern corner of the bay inside
Watering Point, both by dredging and on shore. The hauls are united as —

STATION XXXVII.— North-west to north-east of Watering Point, about 200 yards
off shore ; depth 7 fathoms ; bottom fine dark sand with some broken coral in
places. Nearer the shore, inside Watering Point, are small coral reefs.

Various Alcyonaria and living Corals, chiefly Madrepores ;

Synapta sp. (?) and Holothuria atra :

Filograna sp. and Leucodore sp. ;

Ccdappa sp. and some Ebalid Crabs, Hippa asiatica, and some Pagurids ;

Margaritifera vulgaris (dead shells).

We then landed at Watering Point to examine the shore, and were struck by the
filthy and insanitary condition of the water which was then being pumped into
water-boats to supply ships, from the old Portuguese tank. We explored the beach
in both directions, and also the cliffs above, and, from the boat, the shallow water
lying off the beach, with a view to reporting on this corner of the bay as a possible
site for our marine laboratory. The advantages are the shelter and protection from the
monsoon afforded by the headland, purity of the sea-water, and the presence of hard
patches at the bottom in places where there is a fringe of living coral, and where we
had found evidence of a few pearl oysters living naturally. The disadvantages are
however very serious, viz., the complete isolation and the comparative inaccessibility.

v Me. Hornell, tow-netting at Galle since, lias obtained these same Copepoda with the addition of
Calanopia ellipHra, Acartia centrum, LaMdoeera clchiincata and a new species of Lichomolgiis.

46

CEYLON PEARL OYSTEE REPORT.

During the monsoon it might often be difficult to reach this spot by boat across the
bay, and the distance round from the town of Galle by land is considerable (see
tig. 6), and the latter part of it steep and with no proper road.
The possible sites at Galle had seemed to be : —

(1.) In the Fort, where the Government offices and European quarters are

situated (fig. 6).
(2.) On Gibbet Island or Glosenburg, in or about Bayley's Villa or the

neighbouring native village (tig. 7).
(3.) At Watering Point (fig. 6).

We now ruled out the last ; and made a further examination of Gibbet Island.
This is much nearer the town, and has a good road leading to it. Some of tin-

~

*l ~^L

3i

3j '

3*.

31

' 4 4 *

Fig. 7. Gibbet Island, Glosenburg and neighbouring creeks, in Galle Bay, showing the position of
Bayley's Villa, recommended by Professor E. Haeckel, in 1881, as the site of a Biological Station.

old P. and O. Co.'s quays and walls would no doubt lend themselves well for
adaptation as tanks ; but, as I have shown above, it is quite a question whether
work would be possible in either of the adjoining creeks during the height of the
monsoon, and whether therefore this locality presents any advantage over the Fort,
which would be more convenient and satisfactory in many ways for European
workers.

Professor Haeckel writing, in 1881, his opinion of Galle as the site for a Marine
Biological Station says* : " But more attractive to me . . . were the magnificent corals,

* English translation — ' A Visit to Ceylon.' Kegan Paul. &c, London. 1883, p. 181.

NARRATIVE. 47

which grew in extraordinary abundance on the surrounding rocks ; even the little
inlet used by Captain Bayley as a dock for his boat, and the stone mole where we
disembarked, were closely gemmed with them, and in a few hours I had added
considerably to my collection of corals. A very large proportion of the multifarious
forms of animal life, which are distributed over the coral reefs near Galle, were to be
seen crowded together in this narrow space — huge black sea-urchins and red starfish
numbers of crustaceans and fishes, brightly coloured mollusca, strange worms of
various classes, and all the rest of the gaudy population that swarms on coral reefs
and lurks between the branches. For this reason, Captain Bayley's bungalow . . .
is particularly well-fitted to be a zoological station, and is only half an hour's distance
from the conveniences of the town."

However, after full consideration, we differed from our German friend and decided
to recommend a site in the Fort as the best position at Galle (see below, p. 92).

On two of these days we landed with a party of our Maldivians carrying ship's
buckets, and, crossing the town, descended the ramparts of the Fort between
"Triton" and "Neptune" Bastions (see fig. 6), in order to collect on the coral reef
which fringes the shore along this side of the town, and in order to examine the
possibilities of the lagoon inside the reef for purposes of pearl oyster work. The reef
there runs at an average distance of about 500 feet from the shore, and the lagoon
varies in depth at low tide from 1 to 6 feet. It is possible to wade over the greater
part of it at a depth of 18 inches or 2 feet. The collecting is very rich, and the
colouring gorgeous. Many common genera of Corals, such as Madrepora, Montipora,
Pocilopora, and Galaxea, greenish-brown Meandrina, vivid grass-green Astrcea or
Favia, and others abound, but even more conspicuous in many parts of the lagoon
are huge colonies of the massive leathery or slimy Alcyonaria belonging to the genus
Sarcophytum and its allies Sclerophytum, Lobophytum, Sinularia and Alcyonium.
We obtained about twelve species of the fleshy Alcyonaria in the lagoon, including
Sarcophytum ehrenbergi, Sclerophytum polydactylum, Scl. durum, Scl. densum,
Lobophytum kedleyi, L. pauciflorum, L. densum, Alcyonium pachycladis, and about
four other species some of which are probably new to science. Amongst the other
fixed forms Nullipores and incrusting Polyzoa are much in evidence forming smooth
layers, filling up crevices and cementing together the separate coral colonies, branches
and broken masses. (Stanley Gardiner has shown the importance of Nullipores in
the formation of reefs. I am inclined to think from what I saw at Galle and also on
the coral formations in the Gulf of Manaar that incrusting calcareous Polyzoa plav
at least as important a part in covering and consolidating the fragile, broken, or
decaying coral colonies. The more abundant and characteristic Algae (other than
Nullipores) growing over the dead corals on this reef are : A small Corallina, three
species of Caulerpa (probably C. racemosa, C. plumaris, and C. sedoides), Halimeda
tuna., Padma commerssonii, Peysonnelia rubra, and the lace-like Vovnvoorstia
spectabilis. Bright green Zoanthids, one a long cylindrical form with two rows of

48 CEYLON PEARL OYSTER REPORT.

tentacles, and compact masses of Palythoa caribboea are also conspicuous. Even the
compound Ascidians (Botryllids and Leptoclinids) are of a brilliant green colour. The
Tunicate fauna of Galle includes a common Ascidia allied to A. depressa of European
seas, a small red Cynthia, a dark brown Ascidia like A. fumigata of the Mediterranean,
a dull-grey Polyclinid (? Arnaroucium), and about half-a-dozen species of Leptoclinids,
one of a lilac colour, one of a rich green, one of a very dark brown, several white and
grey forms, and a large handsome new species with pinnacled upgrowths mottled
black and white, which I propose to describe under the name of Leptoclinam im-thurni.
Turning to non-colonial and more or less wandering animals, a feature of the lagoon
is the huge black, brown and mottled Holothurians, which lie about on the coral
sand and the commoner forms of which (Holothuria atra, II. marmorata, II. vagabunda
and H. tenuissima) are fished as "trepang." Some others (Actinopyga mauritiana)
have a flattened under-side and are coloured conspicuously black and white ; and we
were fortunate in finding three species which have been described as new by
Mr. Pearson, viz., Thyone homelli, Actinopyga serratidens and Holothuria gallensis,
Long-spined purple Echinids, large Ophiuroids, star-fishes, and other Echinoderms
are found. There are Turbellaria, including a beautiful white species with black
mottling which, Mr. Laidlaw tells me, will require a new genus near to Discocelis.
The Polychaete worms include spinous Polynoids, a large olive-green Loimia, Eurythoe
latissima, Onuphis niacula.ta, Notocirrus trigonocephalus, Cirratulus sp., a small
speckled Polymnia, a huge Sabellaria (S. bicornis), Spiochaiopterus herdmani, n. sp.,
Hornell (under stones), species of Am phinome, Nereis, Syllis (with buds), Sabella
fusca, Lepidonotus crispatus, Ophryotrocha, Amplntrite, Pista, and others. We got
an orange-red Nemertine, and a white species with red lines ; also a pale yellow
Bcdanoglossus in the calcareous sand under stones. There were many Pagurids — one
a brilliant species with scarlet facings, and having the chelse and other limbs barred
with light blue and black alternately. The Amphipods we collected in the lagoon
include, Mr. Walker reports. Hyperia galba, Hyperoche cryptodactylus, Leptophoxus
uncirostratus, Stenothoe monoculoides, Erichthonius abditus, Platophium sp., Mara
rabromaculata. and a new species of Ampelisca. Amongst the numerous Molluscs
are Cyprosa rnoneta, C. mauritiana, a Plcurobranchus, an orange Dons, an Aplysia,
an Octopjtis, Ilaipa conoidalis, Pleurotoma nodifera, Nerita sp., Terebra sp., several
other Cowries and Cones, Callochiton platessa, and a new species of Chiton which
Mr. Sykes has described as Ischnochiton herdmani. There were numerous brilliantly
coloured fishes, including the curious little Antennarius marmoratus, Less.

This, of course, does not attempt to be a complete list, but merely to give some
idea of the variety and abundance of the shore fauna at the spot which we eventually
selected as the best in Ceylon for a Marine Biological Station.

On February 16th, at 8 a.m., in Galle harbour, the sea-tempei-ature was 79° F.,
and the specific gravity T023. On February 17th, at 7 a.m., off Watering Point, the
sea-temperature was 78"8° F., and at 6 p.m., at the same place, it was 80° F. At both

NARRATIVE. 49

times the specific gravity was T023. On this latter day we dredged and trawled
outside Galle Bay, beginning at the south-east off Watering and Unawatti Points
and working westward to the Gallehogalle Bank. The first three hauls of the dredge
may be considered as Station XXXVIII. , on the eastern side of the entrance to the
bay, while the remaining three hauls along with three hauls of the trawl form
Station XXXIX., to the westward, up to Gallehogalle Bank.

STATION XXX VIII.— Outside Watering Point and Unawatti Point, from \ a mile
to \\ miles off land ; depth 9 to 22 fathoms ; bottom sand and mud with many
shell fragments ; dredged.

Hnlicornaria saccaria, Gorgonia sp., Spongodes sp. ;

Spatangoid, Clypeaster humilis, and Echinodiscus auritus, Astropccten poly-
acanthus (?), Ophidiaster cylindricus ;

ThaJenessa im-thurni, n. sp., Glycera sp., Hyalincecia sp., and Worm-tubes;

Portunids and other Crabs, some Macrura ;

Strombus sibbaldii, Eburna canaliculata, Oliva gibbosa, Philine sp., and Area
compact a ;

Molgula (small species) ;

Branehiostoma lanceolatum (at 9 fathoms, several), B. (Dolichorhynchus) indicus
(at 9 fathoms).

STATION XXXIX.— From 2 miles south of Point de Galle westwards to Gallehogalle
Bank; depths 16 to 30 fathoms; bottom fine sand; stones and Nullipore on the
bank ; dredged and trawled.

Polytrema miniaceum and other Foraminifera ;

Stephanoseris rousseaui, Spongodes, Eunephthya and Gorgonids (sev. spp.) ;

Astropecten hemprichii, Stellaster sp., Salmacis bicolor, Lovenia elongata, Echino-
discus auritus, Clypeaster sp., and Antedon sp. ;

Serpula actinoceras, Polyzoa (many) ;

Squilla, Gonodactylus, Alphens, Amphipods and Isopods, Pontonia, various
Pagurids and Grabs (one infested by Sacculina) ;

Philine sp., Strombus sibbaldii, Sepia sp., Scpiola sp. ;

About 1350 Fish — of which 500 were small flat fish belonging to about 5 species
and ranging from h inch to 4 inches in length, most being from 2 to 3 inches : —

Cynoglossus sp., Rhomboidichthys (2 spp.), Arnoglossus (?), Pleuronectida? (very
many), Gobiidge (768, from 2 to 5 inches long), Callionymus candicaudatus (30, from
2 to 3£ inches long), and C. sagitta (50, from If to 3 inches long).

This sandy area lying to the east of Gallehogalle Bank and giving a uniform
stretch for some miles at a depth of 25 to 30 fathoms is evidently a fish " nursery," or
region where young fishes, both fiat and round, belonging to 8 or 9 species and
including such valuable forms as "Soles," "Turbot" and ■•Plaice," congregate in

H

50 CEYLON PEARL OYSTER REPORT.

great numbers. In one haul of short duration we obtained about 1350 young fish,
including 5 kinds of flat fish.

The Tow-nettings this day (February 17th) were very rich and included : —

Trichodesmium erythrceum, Ceratium, Radiolaria ;

Various Siphonophora and Ctenophora ;

Sagitta (large), Larval Annelides, and some Syllids ;

Copepoda — Many beautiful species, including Calocalanus pavo, Metacalanus
aurivillii, Labidocera pavo and L. acutum, Centwpages gracilis, Candaci<< catula, and
C. truncata, Oithona plumifera (colourless with little plumes of scarlet, and having
pale lilac egg masses), and a new species of Euchceta — 36 species of Copepoda in all ;

Also many larvae — Nauplei, Zoea, Phyllosoma (many), Erichthus and Alima, larval
molluscs and worms ;

Appendicularia, Doliolum and Salpa democratica-mucronata (large).

On Februaiy 18th we left Galle, and spent the day in dredging in the deep water
further out than on the previous day, and onwards up the west coast on our way to
Colombo. A considerable part of the time was spent on and off the 100-fathom line
south of Galle.

At 6.30 a.m. at about 3 miles south of Point de Galle the sea- temperature was
79-5° F., and at 6.30 p.m. when we anchored for the night at 3^ miles south of
Barberyn Lighthouse it was 80° F. ; at both times the specific gravity was 1 "023.

The day's dredging may be divided into 3 stations —

STATION XL.— About 10 miles oft' Watering Point, direction south by west; depth
34 fathoms ; bottom coarse sand, shells, coral fragments, Nullipores and
JSalimeda ; dredged.

Polytrema miniaceum, Alveolina boscii, Orbitolites eomplanata, Heterostegina
depressa, and Amphistegina lessonii ;

Tcthya sp., some Tetractinellids, Bhizochalina Jistulosa, and Horny sponges;

Chironephthya variabilis, Plexaura indica, Briareum sp., Solenocaidon sp.,
Gorgonids (many), Cavernularia obesa, Lituaria phalloides and several species of
Pennatulids, Flabellum sp., Caryophyllia sp., Stephanoseris rmisseaui ;

Hydroids — Sertularia distans, S. (? n. sp.), Antennella allmani, Zygophylax
tizardensis, Idia pristina, Lytocarpus (? n. sp.);

Clypeaster scutiforrnis (?); Lovenia elongala, Phyllacanthus baculosa and Cidaris
metularia, Echinothrix calamaria ;

Species of Protula, Glycera, and Hyalincecia ;

Polyzoa — a large number of species, of which Miss Thornely has already identified
the following, Cellepora cidaris, C. boryi, C tritubercidata, Flustra spoliata,
Chorizopora brongniartii, Cribrilina radiata, Micropora coriacea, Smittipora
abyssicola, Membranipora cornigera, and also species of the genera Lepralia,

NARRATIVE. 5 ]

Stomatopora, Idmonea, Cellar in, Schizoporella, Membranipora, Steganoporella,
Smittia and Adeoita ;

Galathea sp., Dromia sp., and several other small Crabs ;

Tonicia pectinoides n. sp. (Sykes), Turritella sp., Ceratosoma, and other Molluscs;

A red species of Cynthia and Ascidia sp. (probably both new).

STATION XLL— South of Galle, about L2 miles off land; depth, along the
100-fathom line; bottom composed oi masses of calcareous blanched and
ramifying Foraminiferal tubes (Ramulina sp.) ; dredged.

Tetractinellid sjjonges ;

Dendrophyllia sp., Caryophyllia sp., Oirrhipathes spiralis, Antipathes sp.,
Gorgonacea (many— half a dozen species) ;

Actinocucumis donvani, n. sp. (Pearson), Phyllacanthus baculosa, various
Ophiuroids, Asterina cepheus, Stellaster sp., Actinometra sp., Echinanihus rosaceus;

Pagurids and small Crabs ;

Avicula radiata (living on Gorgonids), Pleurotoma nodi/era, Coitus sp., and a few
other shells.

STATION XLIL— Off the Coast, about 4 miles south of Barhervn ; depth 40 fathoms ;
bottom muddy ; dredged.

Stephanoseris rousseaui (many, with Gephyrea), Caryophyllia sp., Para-
cyathus sp. (?) ;

Echinids (small), Pentaceros nodosus, Astropecten hemprichii, Pteraster sp. ;

Aspidosiphon sp., Pectinaria sp., and some muddy worm tubes;

Dentalium sp.

On February 19th, at 6.30 A.M., G miles west of Kaltura, the sea-temperature was
79-3° F. and the specific gravity T023. At 1 p.m. this afternoon we lowered a white
enamelled dish measuring 9 inches by 12 inches on the sounding line and found that
it was distinctly visible to a depth of at least 17 fathoms — the sky being cloudy and
the sea calm.

A good deal of ground was covered during the day (the last of our present cruise),
and nine hauls of the dredge were taken between Kaltura and Colombo, at depths ot
from 20 to 30 fathoms. These may be divided into four stations : —

STATION XLIII. — Six miles due west of Kaltura, (or Kalutara); depth 22 fathoms;
bottom hard sand with Nullipores ; dredged.
Axinella donnani ;

Juncella juncca and Scirpearella sp., Epizoanthus sp. (on Murex), Stephanoseris
rousseaui, and Heterupsammia rnichelini (with Gephyrea), Flahellum sp., Caryo-
phyllia sp., and other small solitary Corals ;

Cucumaria imbricata, Clypeaster scutiformis, Lovenia elongata ;
Aspidosiphon coral,licola. Hyalinoscia sp., Pectinaria sp. ;

H 2

52 CEYLON PEARL OYSTER REPORT.

Melita obtusata, Mmra rubromaculata, and other Amphipods, some Pagurids, and
some Peneids ;

Murex tenuispina, Terebra sp., and some Lamellibranchs.

STATION XLIV.— Five miles north-west of last station ; depth 30 fathoms ;
bottom fine sand and worn fragments of Coral ; dredged.

Hydroids — Halicomaria setosa, and H. saccaria, Lytocarpus (? n. sp.), Monostachys
dichotoma, Idia pristina, Sertularia distans, Sertularella sp. , Halecium sp., and
others ;

Stellaster sp., Linckia diplax, small Temnopleurids, Clypeaster humilis;

Clceosiphon aspergillnm, Peetinaria sp., Sabellaria bicornis, and some worm tubes ;

Caprellids, CaJappa sp., Portunids and other Crabs;

Philine sp., Murex tenuispina and many other Gastropods ;

Molgula sp.

STATION XLV.— Four miles West of Pantura (or Panadure) ; depth -J5 fathoms ;
bottom sand, shells and dead Corals ; dredged.

Various Corals ; Gorgonia, and Melitodes ;

Astropecten sp., Ophiothrix aspidota and other Ophiuroids ;

Hyalinceeia sp. (many), Thalenessa im-thurni, n. sp. (Hornell), Iphione muricata,
Lepidasthenia Julvovittata, Eunice sp., Stylarioides iris, Cirratulus sp., Serpula
nctinoceros, and some worm-tubes ;

Various Crabs (not yet determined) ;

Strombus succinctus, Mullens vulgaris, and a few other Molluscs :

Molgula sp.

STATION XLVL— From oft' Mount Lavinia northwards to off Colombo, from 7 to 12
miles oft' shore ; depth 25 to 30 fathoms ; bottom Nullipore balls (Lithothamnion
fruticulosum), Coral fragments, and some Orbitolites sand ; five hauls of the
dredge.

Orbitolites eomplanata, Alveolina boscii ;

Rhizoehalina Jistulosa, Tethya sp., and other sponges ;

Hydroids — Sertularia distans, Sertularella, sp., Halecium sp., Monostachys
dichotoma, Idia pristina, Halicomaria setosa, Lytocarpus (? n. sp.) ;

Chondractinia sp., and some sand-encrusted Anemones, Chironephthya variabilis
(splendid arborescent colony having the axis and main branches white, and the twigs
crimson lake), Solenocaulon tortuosum, Juneella juncea, Scirpearclla sp., and other
Gorgonacea (many), small species of Fungia, and other solitary Corals ;

Actinometra sp. (dark coloured, on the dark twigs of Chironephthya) , Actinometra
sp. (large, orange coloured), Antedon sp. (small), Phyllaeanthus baculosa (many
large), various Ophiuroids, Laganum depressum, Clypeaster humilis ;

Nemertine (red), Trophonia sp., Polynoids, Serpula actinoceros, Eunice sp. ;

Polyzoa — (many, including Retepora sp., Cellepora, Schizopvrella. Adeona, Gemelli-

NARRATIVE. 53

pora, and Cribrilina). Most of the Polyzoa are strongly calcareous and brightly
coloured (scarlet) forms ;

Crabs (porcelain white, two species (i) on the white branches of Chironvphthya),
and other small Crabs ;

A new species of Chiton. (Tonicia pectinoides, Sykes), Harpa conoidalis, Strombus
succinctus, Murex tenuispinus, Murex haustellum, Conus betulinua, Natica mammilla,
Malleus vulgaris, Philine aperta (?) ;

LeptocUnum sp., Rhodosoma sp., Styela sp., Molgula sp., Cynthia ('. n. sp.) ;

A small banded Sole (Synaptura cornuta).

Tow-net gatherings taken during the day were notable for the abundance of
Radiolaria, colonial as well as solitary — Collozoum and others, also Trichodesmium
erythrceum, some pelagic planarians, Syllids, Halobates, Tornaria, and the Copepoda-
Centropages furcatus, C. gracilis and C. tenuiremis, n. sp., Calocalanus plvmosus,
Mecynocera clausi, Oithona plumifera, and about 20 others.

Although the depths were greater than that of the paars further north, it is
important to note that the bottoms at several of these localities off Mount Lavinia
and elsewhere south of Colombo were hard, clean, and apparently very suitable for
the attachment of pearl oysters, being largely formed of the same balls of Nullipore
(IAthoihamnion fruticulosum) which characterise the paars in the Gulf of Manaar.
It is very probable that this bottom extends into shallower water, and that suitable
spots may be found nearer shore upon which the pearl oyster might be cultivated.
It is said that a pearl oyster bank once existed off Mount Lavinia.

On the evening of February 19th we arrived at Colombo. In this first cruise in
the s.s. " Lady Havelock," in addition to making a preliminary survey of the more
important pearl oyster banks, we had sampled the bottom conditions and the fauna at
various points round the island, and had made a special examination of the several
localities (Palk Bay, Trincomalee and Galle) to which our attention had become
directed. We had also considered these last and other localities very carefully with
the view of choosing the best site for a small marine laboratory in which to carry on
investigations and experiments with the pearl oyster. Our conclusion at the end of
the cruise was that of all the places seen in coasting round the island only two would
be at all suitable for this purpose, viz., Trincomalee and Galle.

Of these, Trincomalee has the distinct advantages of (1) complete shelter from the
monsoons, and (2) natural beds of pearl oysters living in the harbour; but on the
other hand the following may be noted as more or less serious objections :—

(1.) The specific gravity of the water is low, between 1"019 and I "021 as compared

with T023, the usual reading in the Gulf of Manaar ;
(2.) The plankton at the time of our observations seemed sparse compared with

that at Galle and in the Gulf of Manaar ;
(3.) The distance, and therefore the time necessary in taking live oysters round,

from the Gulf of Manaar is much greater. In the case of Trincomalee a

54

CEYLON PEARL OYSTER REPORT.

steamer such as the " Lady Havelock" would take about 30 hours from the

Cheval Paar, while Galle could be reached in about 18 hours;
(4.) The bottom is muddy and is, in most parts, unsuitable for oyster culture, and

the water is not comjjarable in purity with that in the Gulf of Manaar.

Consequently it is probable that although some oysters may live at

Trincomalee, they will not grow so rapidly and healthily as on the pearl

banks ;
(5.) The difficulty of access from Colombo and the distance from the scientific

libraries and museum would be a real disadvantage to naturalists working

continuously at Trincomalee ;
(6.) Finally, for a Marine Station where ordinary biological investigations would be

conducted, Galle presents a richer general fauna than Trincomalee, and has

the additional special advantage of a coral reef and lagoon where collecting

and observation can be easily carried on.

Galle as a locality no doubt also presents some disadvantages, the worst of which is
that the bay lies open to the south-west monsoon ; still there is the lagoon, parts of
which could no doubt be made use of. The other advantages, the purity of the
water, the richness of the plankton, the shortness of the journey from the Gulf of
Manaar and the convenience of proximity to Colombo, render Galle, in my opinion,
much the best site in ( 'evlon for a Marine Biological Station, and these eventually
caused us to fix there our temporary laboratory, in which Mr. Hornell was to carry
on his work after I left the island.

I was asked, however, before deciding finally, to consider various spots in the Gulf
of Manaar, such as Aripu, Chilavaturai, Kodramallai and Manaar, all on the shores of
the pearl oyster region, and these I visited during our second cruise in the " Lady
Havelock."

$

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The s s. " Lady Havelock,'' employed by the Ceylon Government for the pearl oyster investigation,

February and March, 1902.

NARRATIVE. 55

SECOND CRUISE.

On returning to Colombo, from this first cruise, for the purpose of joining Captain
Donnan, the Master Attendant of Colombo, in his inspection of the pearl oyster
banks, I saw for the first time the native barque " Rangasameeporawee " and the
steam-launch " Serendib," and on examining them critically it was obvious, both to
myself and to the ship's officers who were with me, that neither vessel would be able,
without considerable changes, which could not be effected in time, to carry on the
work which 1 still bad to do. < >n pointing this out to Captain Donnan, he agreed
with me, and when we waited upon the Lieutenant-Governor and represented the
matter to him, he promptly authorized us to arrange for the engagement of the
" Lady Havelock " for a further period of three or four weeks, as might be necessary,
from 24th February. Thus it resulted that the " Lady Havelock " accompanied the
two native barques "Rangasameeporawee" and "Sultan Iskander" and the
s.s. " Serendib" to the Gulf of Manaar, where, in addition to carrying on my special
work, she was on occasions of service in towing Captain Donnan's barque and so
saving some valuable time.

This second cruise of the "Lady Havelock" lasted from 24th February to 20th
March, inclusive, three weeks and four days. During the greater part of that time
our steamer kept near to Captain Donnan's barque, and we accompanied him in his
inspection of the banks. Not only had we thus the full advantage of the various
vessels and their crews by means of which to obtain specimens and information, but
Mr. Hornell and I were also able to talk over the work daily with Captain Donnan
and his successor, Captain Legge. Later on we were joined by Sir William Twynam
from Jaffna. That gave a unique opportunity of hearing from these two veteran
inspectors and investigators about former conditions of the various banks and details
of the past history of the pearl fisheries.

During this cruise the early morning and forenoon were usually occupied in
following the operations of the divers, and in examining and recording the material
brought up from different parts of the various "paars." About midday, when the
divers ceased work, Ave started off in the " Lady Havelock " to dredge the neighbouring
grounds between the oyster banks, or on parts of the paar in regard to which we
wanted further information. In this way, beginning in the north of the district of
Aripu, we examined the large and important East and West Cheval banks and the
Periya Paar and several smaller banks lying some to the north and some to the south.
We also, when in that neighbourhood, landed at various parts of the coast in the
endeavour to find a suitable spot for a small Marine Laboratory, from which oyster

56 CEYLON PEAUL OYSTER REPORT.

culture and experiments could be conducted close to the 1 tanks. We tried Manaar,
Aripu, Chilavaturai, Kodramallai, and later on the shores of Portugal and Dutch
Bays, but without success. We could find no spot on the shores of the Gulf of
Manaar that seemed suitable for the purpose, and none certainly with the natural
advantages of Galle. On several occasions we, in the " Lady Havelock," left Captain
Donnan and the barques for a coujde of days in order to run lines of dredgings
across some of the deeper or more remote parts of the region, especiallv to the north
and west.

Our journal of this cruise is as follows : —

We left Colombo on the afternoon of February 24th, having the barque " Ranga-
sameeporawee " in tow. At 7 p.m., when off Negombo, the sea-temperature was
79"8° F. and the specific gravity T0235. The following morning, at 7 A.M., off
Kalpentyn Island, the temperature was 79° F. and specific gravity 1'023; while at
7 p.m., when we anchored at 2f- miles south-south-west of Chilavaturai, the
tennperature was 80"8° F. and the specific gravity 1"022 — these temperatures being
about 2° F. higher than we had found in the same sea three weeks before.

A tow-net gathering was taken at 5 miles north-north-west of Kodramallai
Point. It contained a great quantity of the zoeas of Crabs, some new green
Copepods (Pontella dance, n. var., Labidocera, n. sp., and Pontellopsis, n. sp.),
Sagitta, Lucifer, larvae of Gastropods and Lamellibranchs. There were also many
green filamentous Algae, about 20 other Copepoda (Eucalanus subcrassus, Rhin-
calanus cornutus, llyopsyllus affinis, and Centropages, n. sp.) and many diatoms.
One large bluish-green Copepod (the new Pontellopsis) had a plate-like radially
marked mass of spermatophores on its hinder end (genital segment) which was so
conspicuous as to be visible to the naked eye as a yellowish patch.

We went ashore at Chilavaturai, running in as far as we could in the " Serendib "
and then in the ship's boat. Where the "Serendib" stopped, in 13 feet of water,
the screw stirred up quantities of delicate red Algae (Hypnea muscifonnis and Poly-
siphonia sp.) and very fine filamentous green stuff (Cladophora sp.) such as we also
found growing in some parts of the Cheval Paar, and to which the minute oyster
spat commonly becomes attached. These Algae apparently grow on a coarse sandy
bottom in various parts of the district.

Chilavaturai is famous in the annals of the Ceylon pearl fisheries as having always
been the site of the fisheries camp during British times, except in the case of the
small fishery of 1832 and the three fisheries of the Muttuvaratu Paar in 1889, 1890
and 1891. Sir W. Twynam and Captain Donnan have shown however that there
are reasons why Marichchukaddi, about 10 miles further down the coast, would he, in
some respects, a better site for the camp in future fisheries of these northern paars.

Chilavaturai was one of the spots to which attention had been directed as a
possible locality for the marine laboratory, and we consequently examined some
empty rooms which adjoin the Rest-house ; but found them inconvenient and in poor

NARRATIVE.

57

repair. They might no doubt be adapted to the purposes of a scientific workshop if
the locality were suitable in other respects ; hut the shore is an impossible one.

We then steamed along the coast to Aripu, about 4 miles further north, where I
had been asked to examine an empty government bungalow. This had four large,
lofty rooms, a tine broad verandah and a large walled compound. Beside it were still
to be seen fragments of the ruins of the old Dutch fort, to which our countryman
Robert Knox made his way in 1G79, when he escaped from Anuradhapura, after 20
years' captivity in the hands of the King of Kandy. This bungalow, so far as the
house goes, could be made a perfectly siiitable residence and workshop for the marine
biologist were the locality suitable in other respects — but it is not.

At Aripu we visited the ruins of the " Doric," a classic structure often referred to
in the reports of the pearl fisheries, and which we had been using as a landmark. It
was built by Lord Guildford a century ago, as the official residence of the Governor
when he attended a fishery, but being unused it later on fell into ruins. It has
always served however as a useful and conspicuous object from which to take

f v *

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fl^^H St

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Fie. 8. The "Dori

as it was at the beginning of last

century — from Cokdinku's plate.

Fig. 9. The " Done " as it now is — from a photograph
taken in February, 190:2.

bearings on the pearl banks. The figures given here show (tig. 8) its original
appearance, from the plate in Cordiner's "Ceylon," 1807, and (fig. 9) its present
condition from a photograph I took in February, 1902, with Captain J. Donnan, C.M.G.,
late Inspector of the Pearl Banks, in the foreground.

In the evening (February 25) we put two tow-nets out, one near the bottom and
the other at the surface. The deeper net contained a large amount of the filamentous
red Alga? (Hypnea musciformis, Polysiphonia, &c), along with Molluscan and Annelid
larvae, Coscinodiscus, &c.

The surface net had Coscinodiscus and 14 species of Copepods, including Calanopia
aurivillii, Metacalanus aurivillii, Ilyopsyllus affinis, and a new species of Peltidium.

On February 26th, at 7 A.M., 2f miles south-south-west of Chilavaturai, the sea-

i

58 CEYLON PEARL OYSTER REPORT.

temperature was 78*1° F., and at 7 P.M., on the south central part of the Cheval
Paar, the temperature was 79'5° F. At both times the specific gravity was 1"023.

A bottom tow-net which had been down all night was found on the morning of
February 26th to contain great quantities of small Copepoda with very long caudal
setaa (Ectinosoma roseum and E. atlanticum), also Euterpe acutifrons and a dozen
other species, along with some Medusoids and Ctenophores.

About mid-day, when going under easy steam, we put out a tow-net which we had
contrived with a canvas funnel in front of the mouth and having the narrow end
forwards, so as to reduce the volume of water entering and so the pressure on the
net. It worked well and gave us good hauls containing chiefly Nauplei, Zoeae, 41
species of Copepoda, including the large blue PontelJa securifer and the small long-
tailed Ectinosoma atlanticum, Centropagcs violaceus, Metacalanus auriviUii (common),
Pseudodiaptomus auriviUii (male previously unknown), and also Ceratium (two
species), Peridinium, some Trochospheres, Radiolaria, many Diatoms, especially
Coscinodiscus and long rod-like forms, Sagitta, Salpa, Appendicularians, Pteropods,
and some Lamellibranch fry. It was evident from this and many other hauls that
the microscopic plankton of the sea, both at surface and bottom, was very abundant
in the Gulf of Manaar, and this must be of very great importance in feeding the pearl
oysters.

We boarded the barque " Rangasameepoiawee " later in the morning, and found
that she was anchored on the position of the " shoal-buoy," a mark that Captain
Donnan has been in the habit of bringing with him on each inspection in order to
indicate the north end of the long shoal which runs northwards from Karativo
Island to the southern part of the Cheval Paar. The buoy (a large structure of
casks and planks bearing a mast) is anchored over a sunken tank, and serves as a
useful mark to take bearings from during the inspection of the banks.

"We now set the divers to work to bring us up samples of the bottom, a rather
coarse white quartz sand upon which great masses of fine green and red filamentous
Algas grow. These contained Hypnea musciformis, and undetermined species of the
genera Cladophora, Ceraraium, and Cluetomorpha.

The divers brought up quantities of this weed, upon which, when put in our small
glass aquaria, we soon found great numbers of very young pearl oysters — the spat
being densely crowded in some places on the filaments of Algas. The smallest size,
of which there were very many, was about 0-5 millim. in diameter, but other samples
measured up to 4 millims. This spat was evidently very young and the smallest
had probably just become attached during the last few days. A quantity was kept
alive under observation, some in wooden tanks on the barque and some in our glass
aquaria on the "Lady Havelock." It was found to be restless and active, and to
leave its attachment and crawl freely about on the Algas or on the glass sides of the
aquaria. For example, one specimen (a) crawled 5 inches up the glass within
18 minutes, the last 2f inches in 12 minutes: another (h) crawled •'> inches in

NARRATIVE. 59

12 minutes ; while a third (c) did Ly- inch in the same time. Both a and b travelled
at a greater rate at the beginning than towards the end of the time.

In the green weed were also large numbers of a white Leucothoid Amphipod
(which Mr. Walker considers to be a new genus), some interesting new Caprellids,
and a good many llissoadike Gastropods about 7'5 millims. in length. Some specimens
of a small white Synapta were also brought up in the sand.

In the afternoon we dredged and trawled from the "Lady Havelock " in the area
lying south-west of the Cheval Paar. All these hauls may be united as—

STATION XLVIL— About 4 miles south of the West Cheval Paar; depth 8| to
9 fathoms ; bottom sand overgrown with green Alga; ; dredged.

Phyllospongia holdsworthi, Axinella donnani ;

Astropecten hemprichii, Amphiura sp. ;

Sabetta phwotcenia, Serpula sp. ; various Crabs ;

Pearl oysters (a few large and many very small), ApJysia pulmonica (!) ;

Molgula sp. ;

Fish — both round and flat — including Pegasus draeonis, Upeneoides tragula,
Gobius biocellatus, G. masoni, Teuthis oramin, Percis pulcheUa.

On February 27th we joined Captain Donnan in the morning on board the barque
in order to see the work of the divers. During this and some following days two
sets of diving operations were carried on simultaneously. Four large whale boats,
each containing 10 or 12 natives under the charge of a tindal or boatswain, were
engaged in making a survey by means of concentric equidistant circles — the boats
circling first within a distance of \ mile, then between \ and ^ mile, and finally
between ^ and f mile from the barque, which was anchored in the centre — and
keeping their distances approximately by means of radially placed buoys bearing
flags. From these boats the divers went down at frequent intervals, and the result of
each dive was recorded by the tindal on a plan. At the same time we had a set of
two or three divers in the " Serendib" (fig. 10), and with these we took samples from
between the paars or in any other localities where we wanted further information to
supplement the results of the inspection boats.

The ground we worked over this morning was mostly formed of dead coral and
Nullipore with some Sargassum and other Algse, the depth being 6 to 6|- fathoms.
Pearl oysters of two ages were found ; the larger being estimated at 3 years old and
the smaller size at 6 months (see fig. LI). The oysters were accompanied by great
quantities of small boring Gastropods (the " Oorie" of the divers) belonging to the
genei'a Purpura, Nassa, Sislrum, Pinaxia, Natica, Muvex and Turbinella (mostly
Sistrum spectrum and Pinaxia coronata), and in places were entangled in the byssus
nests of masses of "Suran" (Modiola barbata). A deep purple spreading sponge
(? Pachychalina multiformis), upon which were opisthobranchs of the same colour
(Aplysia sp.) was common.

I 2

60

CEYLON PEARL OYSTER REPORT.

Around such hard patches the bottom is all sand, in some parts coarse, in others
finer, and varying in constitution from almost pure quartz to a neritic deposit formed
mainly of the shells of Foraminifera {OvUtolites, Heterostegina, Alveolina, &c). On
the sand fewer oysters are found, but they cannot be said to be absent, especially in
the neighbourhood of a "paar" (or hard patch). When present they are generally

^ «_asafc^ ..» S ■ . , _„^2t

•

sGhBSk *? 7 "

Fig. 10. Our two divers on the
" Serendib."

Fig. 11. Young pearl oysters, about six months old,
attached to a dead Madrepore Coral.

united in clumps of several fastened together by their byssus threads or attached by
si niie hard object such as a Nullipore nodule, a dead shell or a fragment of coral.
In some cases two or three large oysters (about 3 years old) will form a centre upon
which a great many young ones (about 6 months old) are fastened (fig. 12). In
some places there is undoubtedly overcrowding, the larger oysters being completely
surrounded with masses of young piled so closely as to smother some and probably
interfere with the growth of all. This is a precisely similar case to that of the
overcrowding found in European mussel beds, where the advantage of thinning out
and transplanting is well known.

We got the divers to construct for us, after several dives to verify the details, a
model on the deck of the " Serendib" showing the distribution of oysters on the rock
and sand at the bottom. Fig. 12 is from a diagrammatic drawing (in bird's-eye-view)
showing what they produced.*

Although oysters lying on the sand may manage to survive for a time, especially if

* These and our other conclusions in regard to the configuration and constitution of the paars and the
distribution of the pearl oysters were verified later on by Mr. Hornell when, at the fishery in the
spring of 1903, a European diving costume being available, he was enabled to make a personal inspection
of the bottom.

NARRATIVE.

r>i

united in clumps, it is evident that they are in a dangerous position and are liable to
be overwhelmed and smothered at any time by a shifting of the loose bottom.

There is apparently plenty of available hard ground with a dead coral, or
consolidated sand, or Nullipore bottom round about the known paars to which young
oysters from unsuitable sandy grounds or from overcrowded spots could be easily

Fig. 12. Diagram showing the arrangement of pearl oysters (large and small) in clumps on the sand

and singly attached to flat ledges of rock.

moved. We accumulated many observations bearing on this question during the next
few weeks and also during Mr. Hornell's inspection visit to the banks in November,
1902, and during the fishery of March and April, 1903. It will be further discussed
in our Recommendations at the end of this report.

In order to trace the extension of the pearl oysters beyond the limits of the
recognised paars, we took a number of hauls of the dredge, in the afternoon, from
south to north in the middle between the East and West Cheval paars on, in the
main, a sandy bottom. These may be joined as —

STATION XLVIIL— Between East and West Cheval paars ; depth 6|- to 7^ fathoms ;
bottom sand, fragments of dead Coral, shells and Nullipore ; dredged.

Some solitary Corals, Haliconiaria saccaria ;

Sal/mads sulcata and S. dussumieri, Laganum depressum, Locenia elongata, many
Clypeaster humilis, Eehinolampas oviformis ;

Polyzoa — 13 species, amongst which are Lepralia dorsiporosa, Micropora coriacea,
Scrupocellaria scrupea, Schizoporella lineata, Cellepora avicularia, Idmonea serpens,
Smittia reticulata and Brettia sp. ;

Stenothoe marina (variety) and other Amphipods ; pearl oysters (very many, mostly
young), T'urbinella rapa and a few common Molluscs ;

Asymmetron (Heteropleurou) cingalense. A new species of Emmelichihys was also
obtained here at a later date.

62

CEYLON PEARL OYSTER REPORT.

A single haul (the second) in the middle of the area in question gave us nearly
2 cwt. of pearl oysters, large (3 years old) and small (6 months). Most of them were
attached to fragments of worn coral or to one another.

Two hauls of the dredge upon the northern end of the Cheval region, depth
63- fathoms, gave much the same hottom and result, but with fewer living pearl
oysters. The sea-temperature this day was, at 7 a.m., 78*3° F., and at 9 p.m., 79'5° F.,
and the specific gravity on both occasions 1"023, at anchor on the South Cheval. The
following day (28th) the temperature, at 7 A.M., was 78° F., and at 6 p.m. it was
79 "3° F. on the South-east Cheval. The specific gravity was still 1'023.

We now had various sets of pearl oysters under close observation in our wooden
tanks, glass aquaria, and sea- water baths, on both the barque and the " Lady
Havelock," in order to test powers of detaching and travelling and re-attaching,
regeneration of the byssus when cut and when torn out, and similar matters; but
the results of these experiments will lie given separately further on in the report.

On the morning of February 28th we (in the "Serendib") traversed from south to
north the inspection circle (l|- miles in diameter) which covered the southern end of
the East Cheval, 18 dives being taken at about equidistant points with the following-
results. This will serve as an example of the many lines of dives we traversed during
the next few weeks.

Dives.

Bottom.

Pearl oysters.

Any other animals.

1

Sand

Few, large and small

Malleus vulgaris.

2

Rock

Large oysters

Modiolar" suran."

3

Sand

Few large, many small

4

Rock

Many large, few small

5

Sand

Many small, some large

"Oorie."

6
7

Rock

Large and small

8
9

Sand

Few clumps, large and small

10

Rock

Clumps of large

Green corals (Fariu), dark green Antedon, and

Alphceus of same colour.

11

Sand

Few clumps, mostly small

Pinna bicolor.

12

Rock

Clumps of large and small

Campanvlaria juncea (" Heather").

13

Sand

None

14

Rock

)>

jj »

15

>j

Small, few

„ ,, and sponges.

16

Sand

None

17

Rock

One large

», I)

18

)»

None

The large Hydroid Zoophyte Campanvlaria juncea, which grows in tufts a foot in
height and looks somewhat like old withered masses of heather, is very characteristic
of this East Cheval paar. The beautiful large pinnate Halicornaria insignis is also
found here, and usually bears the protectively-striped Avicula zebra which is almost

NARRATIVE. M

invisible on the Zoophyte. We also found Meleagrina margaritifera, the large
mother-of-pearl oyster on the south part of East Cheval Paar.

In the afternoon we dredged over the ground lying between the shoal buoy and the
south end of the Periya Paar.

STATION XLIX.— South-west of Cheval to oft' south end of Periya Paar; depth 8£
to 13 fathoms; bottom sand, Nullipores, and dead shells; 6 hauls of dredge.

Lovenia elongata, Echinolampas oviformis, Maretia planulata, Clypeaster humilis,
Echinodiscus auritus, and Echinanthus rosaceus, Holothuria atra ;

Worm-tubes (Sabellaria, Serpula, Filograna);

Tritceta tenuipes, Leucoihoc spinicarpa and other Amphipods, Calappa sp., and some
other Crabs, and Peneids ;

Mollusca [Turritella maculata, Cassis glauca, Strombus sucdnctus, Pinaxia
coronata, &c.), also pearl oysters, Dolabella sp., and a few small Octopods;

Cynthia sp. ;

B ranch iostoma lanceolatum, var. belcheri (14 specimens), Asymmetron (Hetero-
plcuron) cingalense (2 specimens).

When in one of the hauls Ave touched the south end of the Periya Paar we
obtained a great number of young pearl oysters, just as we had found before, and
were to find again in our later examination of this bank.

On March 1st Ave moved our centre southwards on to the Modragam paars. At
7 a.m., on the south end of East Cheval, the sea-temperature was 787° F., and at
7 p.m., on the North Modragam, it was 79"7° F. ; in both cases the specific gravity
was l-023. In the morning we made a diving traverse from south to north through
the Modragams to the Cheval. The pearl oysters were not very numerous, but were
exceptionally large, although probably not older than those on the Cheval Paar.
Captain Donna N, from his close observation of the oysters on these paars extending
over many years, feels confident that the shells grow more rapidly, and to a larger
size, on the Modragam than on the Cheval paars, and on the East Cheval than on the
West. Our own measurements made later on bear this out. It is very possible that
these differences may be due to feeding, and that the explanation is that the
conditions become less favourable further from the shore and towards the north-west.
The Modragams are also sheltered by the shoal running up from Karativo Island to
the Cheval.

The details of these dives need not be given. On the whole they show much the
same distribution as those given above. Between the North Modragam and the
South Cheval, in 6|- fathoms, along with abundance of young pearl oysters a few
months old, we found quantities of red Algre (Polysiphonia, &c.) covered with minute
"spat" evidently quite recently deposited.

In the afternoon we dredged again over Station XLIX., from the south-west corner
of the West Cheval to the south of Periya Paar ; the depths found varied from

64

CEYLON PEARL OYSTER REPORT.

8 to 13|- fathoms and the hottoms and animals were much the same as hefore
(including two species of Amphioxus). We found quantities of young oysters in our
last haul, about 5 miles south of Periya Paar, 12 to 13J fathoms, on a firm bottom
of Nullipores and Orbitolites sand, showing that there are outlying patches beyond
the limits of the known paars where oysters may be found. This particular spot
would, however, even if the oysters attained maturity, be too deep for most of the
native divers to work. Their usual limit is about 9 fathoms. We had them a few
weeks later making a few descents for us in 11 fathoms on the Periya Paar, but
they had just time to get a sample of the oysters or whatever lay before them on
arriving at the bottom. Captain Donnan has had exceptional divers who have made
descents for him in 15 fathoms, but they had barely time to secure a single handful
of the bottom before having to come up in an exhausted condition. I timed many
dives and none reached two minutes, very few were over a minute and a half.

Samples from all the pearl oysters we obtained on the different paars from the
clivers or by dredging were examined as to their food, their reproductive condition,
their general condition of body and parasites and as to any stages in pearl-formation.
All these matters will however be dealt with separately further on in the report.

On March 2nd, being now in the neighbourhood of Kodramallai Point and
Marichchukaddi, which was the site of the Camp during the three last pearl fisheries
(1889 to 1891), and also during the recent fishery of 1903, we took the opportunity
to go ashore and inspect, as Captain Donnan thought that possibly we might find a
sheltered corner of the bay suitable for the marine laboratory.

We landed at Kodramallai Point, and examined the coast (fig. 13) tor a little way

Fig. 13. Part of the'pearl-divers' fleet at Marichchukaddi — from a photograph by J Hornell.

northwards towards the Modragam River, but found it quite hopeless for our purpose.
The rock at the point forms a moderate, headland and runs out seawards as a little
reef. It is apparently all sandstone ; there is no coral, and it gives practically no

xai;i;ativf,

65

protection from the south-west monsoon. The si lore of t lie bay is muddy and tin'
water shallow for a long way off. There is much Zostera, but every living thing
seems covered with a tine deposit of mud.

In the afternoon we sailed for Manaar, which I had been asked to examine and
report upon. The sea-temperature at 7 A.M. on North Modragam was 7t)° F. and at
7 P.M. on the south bar at Manaar it was 81° F., the specific gravity as usual was
1"023 at both times.

We had caught a number of Sea-snakes (Hydrophidse) during the last few days,
and the stomachs of all these were examined to see whether any foundation in fact
existed for the belief that they feed upon the pearl oysters. We found no evidence
of that. Without exception the stomach contents in the snakes we caught were the
more or less digested but still recognisable remains of various kinds of fish. Such
examinations, and the recording of our pearl-oyster
experiments and statistics, went on during the time
spent in getting from one spot to another, and when
lying at anchor. Dr. W. Haxxa, of Liverpool, has
kindly examined the Hydrophidse I brought back
and finds that three species are represented, vi/..,
Enhydris curt us, Hydrus platurus and Hydrophis
fascialus.

On arriving off the south bar at Manaar we took
a tow-net gathering which contained, amongst other
Copepoda, Oitkona rigida, Euterpe acutifrons and
Labidocera acuta. We also caught a large Remora
(EcJieneis naucrates) measuring fully "J4 inches in
length and having a sucker (3 inches long. It was
slate-blue dorsally and of a lighter colour ventrally.
On laving it with the sucker against the upright
bare back of a diver, in the air, it at once adhered so
firmly that one could grasp it by the tail and pull
with some force without detaching the fish (fig. 14).

March 3rd was occupied in enquiring into the
marine biological possibilities of Manaar. The sea-
temperature at 7 a.m. was 7i)°"o F. and at 7 P.M. on the north end of the East (Jheval
was 80° F., the specific gravity being 1"023.

We crossed the south bar in the ship's boat with some difficulty, and went aground
several times in the long shallow muddy passage leading up to the town of Manaar.
The Assistant Government Agent sent for Mr. Y. Vkaspillai, the respected and
experienced Adigar of Musali, who took us round to the various bays and creeks,
showed us the different kinds of shore, and gave us full information as to the fishing
and the shell-fish found locally, and the influence of the tides and winds. The Adigar

D

K

Fig. 1 i. Remora attached to the
back of a diver.

06 CEYLON PEARL OYSTER REPORT.

entirely confirmed our own opinion, formed from what we saw, that there is no spot
in the neighbourhood of Manaar suitable for pearl-oyster work. The North channel
we found is as unsatisfactory as the South, and the great creek immediately to the
north-east of the Fort is quite shallow and muddy. Not even cockle-like shell-fish
can be got to live there, and in fact dead shells have to be imported from Aripu for
calcining to make the " chunam " for betel-chewing. Pyrazus palustris is most
abundant in these muddy shallows. Turtle are also plentiful round Manaar and are
caught by the harpoon, which is a short four-sided iron spike sharpened at one end
and having a ring on one side to which a long cord is attached. The spike is loosely
" fastened to the end of a pole, from which it readily becomes detached when implanted
in the plates of a turtle's back, leaving the animal anchored by the long cord.
Dugong are also taken here, they feed upon the Zostera which is plentiful all around.

On March 4th we were back again with Captain Donnan and his inspection boats
on the north end of the East Cheval, where at 7 a.m. the sea-temperature was 79° F.
and specific gravity 1 "023. The forenoon was spent examining with the divers, in
the " Serendib," the middle part of the East Cheval and the area to the west of it,
on which we found more oysters both large and small than within the usually
recognised limits of the paar itself. In three dives on this western part the oysters
came up attached to coral blocks, in the fourth they were in clumps lying on sand ;
they averaged 15 oysters to a dive.

In the afternoon we dredged from the " Lady Havelock " in the same region and
northwards to the Periya Paar Kerrai and Vankali Paar ; and obtained striking
proof, as on many other occasions, of the superiority of dredging over diving as a
method of obtaining the pearl oysters. The first haul, during which the dredge was
only off the deck 10 minutes, brought up 65 large oysters along with other organisms.
The first few hauls were practically upon Station XLVIIL, dredged on February 27th,
and the more abundant animals obtained* were the same as before (see p. 61) ; while
the remaining hauls further north may be divided into two sets, those about Periya
Paar Kerrai (Station L.) and those of Vankali Paar (Station LI.).

STATION L. — On Periya Paar Kerrai and to the north ; depth 7\ fathoms ; bottom
sand and dead shells ; dredged.
Various common Corals ;
Serpula actinoceros ;

Mara rubromaculata and other Amphipods ;
Pearl oysters, mainly small, Oscanius sp. ;
Branchiostoma lanceolatum and variety belcheri (large and plentiful).

* It will of course be recognised by naturalists that many other minute or obscure forms (Amphipods,
Hydroids, Polyzoa, &c.) were obtained at nearly all these hauls; and these will be treated of in the
special reports that follow.

NARRATIVE.

07

STATION LI. — West of the last Station, on Vankali Paar and southwards ; depth
7\ to 8 fathoms ; bottom sand, dead shells and Coral fragments ; dredged.

Some common Corals {Madrepora and Turbinaria), and Heterocyaihus cequicostatu§
(witli Gephyreans), several Gorgonids (large colonies) ;

Clypeaster humilis and Echinodiscus auritus;

Aspidosiphon sp. ;

Lilljeborgia pallida (a British species !) ;

Pearl oysters, plentiful — both large and small (GO large in a haul).

The Tow-Nets on March 4th gave us : — -Medusae, Sagitta, Alciopa, Appendicu-
larians and about 35 species of Copepoda — some of them in great abundance —
amongst which may be mentioned Mcta-
calanus aurivillii, Centropages, n. sp., and
Calanopia minor.

Some experiments were made during
this and succeeding days in towing pearl
oysters of different sizes, under various
conditions, and at different rates up to
8 knots an hour, which showed us that it
would be easier to transport young than
old oysters in bags, nets or crates hung
over the ship's side (see fig. 15), and also
that old oysters are apparently less able to
withstand the action of a strong current
than younger forms. From the cages and
baskets (generally made of the coir fibre
of the cocoanut) used on these and subse-
quent occasions when pearl oysters were
hung out over the side of the ship we
obtained various small animals, especially
Hydroids, amongst which were a Clara, two
species of Sertularia, a scarlet Eudendrium,
a BougainviUea, and several Plumularians.

On March 5th the sea-temperature was
slightly over 79° F. both morning and
evening, on the north end of the Cheval, with a specific gravity of 1/023. In the
morning as usual we were with the divers (who work from 6 a.m. till noon) working
over the northern end of the East Cheval and outside the paar to the north and east.
Practically no oysters were found. Some fine colonies of the hydroid Zoophyte
Halicornaria insignis, with Avicula zebra attached, were found here (off north end of
Cheval, 6 fathoms). On moving south-east along the edge of the paar to its middle
portion we came upon quantities of a fine brown fucoid Alga smothered in young

K 2

I<^-*1' ' ^ T|

bL_; £** 46? ^^W**t

'"''/ I

■A 1 ^gi

Efl

HI**- .'V' oBSE

Ws&k

gjlfr ,<-4J£

■0

Fig. 15. Two of the clivers on the " Rangasamee-
porawee " with the wire-net and coir cages in
which our experimental pearl oysters were
suspended over the ship's side for two months.

fiS

CEYLON PEARL OYSTER REPORT.

oyster "spat." The Alga was growing on what the divers call "flat rock" — a
calcrete formed by the- cementing together of the sand and shell fragments in situ.
We also obtained at the same spot a fine tnberenlated dark green Holothnrian
(Stichopus chloronotus).

In the afternoon we dredged to the north of the East Ctaeval Paar, running a line
of hauls to the Vankali reef lying about 6 miles to the north and then north-west
alone- the outer face of the reef and so back. Six hauls were taken which may be
united as —

STATION LIL— Between north of Cheval Paar and Vankali reef; depth 3 to 6
fathoms ; bottom sand ; no pearl oysters ; dredged.

Ilalicornaria setosa and 77. saccarla, Lytocarpus (( n. sp.) and Sertularia tenuis,
Cavernularia obesa (many), Virgularia juncea ;

Hermadion sp., Panthalis melanonotus, Psammolycc sp., Onuphis sp. ;

Ostracod (very large, possibly Cypridina forrnosa, or a new form) ; Modiula sp. (in
gelatinous nests), and other Lamellibranchs, Turbinella pyrum, Strombus succinctus,
Pinaxia coronata, Pyrazus palustris, Persona ridens and Bucdnum melanostoma, ;

A sum met ran (Heteropleuron) cultellum.

The Tow-Nets at this locality gave us about 28 species of Copepoda, representing
12 genera. These like the other tow-net results will be given in detail in the report
on the Copepoda, but Messrs. Thompson and Scott give the following as noteworthy
from this haul: — Mecynocera clausi, Paracalanus parvus, Acrocalanus longicornis,
Centroparjes furcatus and a new species, Pseudodiaptomus aurivittii, Labidocera
pavo, L. kroyeri and a new species.

During parts of this day we had living pearl-oyster spat under observation in fiat
wooden tanks and in our narrow vertical " window" aquaria. In the latter, numbers

S>

V

B.

Fig. 10. Arrangement of spat on glass of aquarium 7 minutes after all started from bottom.
B, one individual enlarged, showing the extended foot.

of individuals placed at the bottom started at once to climb up the glass sides and
travelled on the average at the rate of about an inch per minute. At the end of the

NARRATIVE.

(i'.l

first minute 65 individuals were crawling up the glass. At the end of seven minutes
six had reached the surface of the water, a distance of 3% inches. Most of the rest
had attached themselves at various points lower down. The actual disposition on
the glass side of the small aquarium at the end of seven minutes, and an enlarged
figure of an individual when climbing, to show the expanded foot, are given in tig. 16.
The object of tin's record is to emphasize the great activity and the locomotory powers
of the spat at this stage, when it is usually regarded as a sedentary and in tad a
fixed animal. In cliuibinp;, attachmenl

^?.

S&tf

m&z*

'ig,

Sketch of young pearl-oyster spat
attached to Sargassum.

is made hv the base b of the foot, the
distal portion being elongated. Then
the tip a fixes and b at the same time
is freed and the animal is drawn upwards
hv the contraction and shortening of the
muscular foot. Then b fixes once more,
a is extended to a new position and the
process is repeated.

We frequently observed that spat
collected on weed (such as Sargassum,
fig. 17, and Hypnea or Cladophora) very
readily detached itself and wandered
on to other objects or became trans-
ferred to the walls of the vessel, or even adhered together in balls of from 4 to 10
individuals.

We now moved to the north end of the West Gheval Paar, where on March 6th,
at 7 a.m., the sea-temperature was 79-3n and at 7 p.m. 79"5° F. ; the specific gravity
as usual being l-023. In the morning we ran 2 lines of dives, from the " Serendib "
north -eastwards from the northern end of the West to the northern end of the East
Cheval, getting a small number of large oysters (with some dead shells) and consider-
able quantities of young. We also brought up a very fine specimen of Toxopneustes
pileolus with very beautiful and conspicuous pedicellarire, in which the 3 valves are
united by a discoid reddish membrane bordered by a conspicuous white line.

The rest of the day was spent in dredging at a point about 10 miles north of the
morning position. Here 5 hauls were taken which may be regarded as—

STATION LIU. Ten to twelve miles north of Cheval Paar and about VI miles
west of Vankali (or Bangalli) Church ; depth 7h to 'J fathoms; bottom muddy
sand with some dead shells ; no large pearl oysters, only a few small : dredged.
Halimeda and some Nullipores, green Algae and Halophila ovata ;
Axinella dormant, and other sponges;

Lytocarpus spcctabilis, Campanularia juncea, and species (which may be new) of
Haledum, Obelia, and Campamdaria ; Pennatulids and various living Corals;

70 CEYLON PEARL OYSTER REPORT.

Clypeaster humilis, Laganum depressum, Antedon sp. (sev.), and Actinometra sp. ;

Psammolyce sp. and other worms ;

Polyzoa belonging to the genera Lepralia, Adeona, Crisia, and Scrupocettaria ;

Melita obtusata, Erichthonius sp., Siphoncecetes sp. and other Amphipods, Elsia
indica and Lysianassa (? n. sp.), Lamhrus, Pleurophyllidia sp., and Kalinga ornata;

Branchiostoma lanceolatum, and variety belcheri.

The bottom Tow-net at 7 p.m. contained, amongst other Copepoda, Pontella
securifer, Ectinosoma atiantieum and E. roseum, Metacalanus aurivillii and Pseudo-
diaptomus aurivillii — 22 species in all.

At the end of the dav's work we anchored about 15 miles to the north of our
morning position on the Cheval with the view of spending the following two days in
working this northern end of the Gulf of Manaar, above the recognised paars.

In the intervals of dredging and when moving from place to place, we were now
continuously engaged in examining the parasites of the pearl oysters and their
influence upon pearl formation. We also decalcified such small pearls as were found.
This work was continued as time permitted during the next few weeks, and also by
Mr. Hornell after I left. We found various parasites, in the liver especially, some of
which were Platyhelminthian and others Sporozoan in their nature, and some of which
were enclosed in calcareous capsides. Mr. Hornell afterwards determined that
these were Tetrarhynchus larvae of Cestodes, and we have no doubt that they are in
many cases the nucleus of the pearl, and the irritating cause of its formation.

On March 7th, at 7 a.m., the sea-temperature was 79-5° F. and at G r.M. it was
80° F., about 10 miles south of Adam's Bridge. This day and the following one were
spent in continuous dredging in the northern end of the Gulf of Manaar, south of
Adam's Bridge, from south of Thanni-Kodi on Bameswaram Island to south of
Talamanaar on Manaar Island. Eight hauls were taken on the first day and 13
on the second, but although a wide extent of ground, about 18 miles from west to
east, was worked over no natural limits present themselves, and I consider it best
to unite the 21 hauls as a single locality (Station LIV.). We started at about
15 miles south of Thanni-Kodi and worked westwards into shallower water for two
hauls and then southwards into much deeper water (30 fathoms), the dredge eventually
falling "out of soundings." The 5th haul was in 40 fathoms at about 1G miles
south of Thanni-Kodi. Here we obtained Panthalis melanonotus, in a muddy
mucous tube very like the condition in which we find the same genus in water of the
same depth in the Irish Sea. We then ran north into 15 fathoms (6th haul) and
dredged eastward for the two remaining hauls in depths of 10 to 8^- fathoms, at
about 10 miles south of Adam's Bridge. We anchored for the night with Thanni-
Kodi bearing north, 18° W., and distant 10 miles.

The following morning we began dredging at the same spot and worked eastwards
and then south-east through depths averaging 8 or 9 fathoms. In the 8th haul,
south of Talamanaar, we came upon a rough bottom of living coral at 4 to 5 fathoms.

NAUR ATI VE. 71

The 11th haul was upon the Anaivelundan Paar where some of the elephant's-ear
coral {Turbinaria dnerascens and T. crater) from which the paar gets its name was
brought up. The two final hauls were a little south of this on sand and dead shells,
and then we ran for the south end of the Cheval Paar where the barques were
then at anchor.

STATION LIV. — In northern part of Gulf of Manaar, south of Adam's Bridge;
depths from 4 to 40 fathoms ; bottom varied, from sand to living Coral — over
20 hauls of the dredge during two days.

Nullipores, Halimeda, Corallina and other Algfe ;

Orbitolites comp)lanatus, Heterostegina depressa, Ampliistegina lessonii and other
Foraminifera ;

Petrosia testudinaria, Hcdisarca sp. (black), and other Sponges ;

Pennatulids, various dendritic Alcyonaria, Sclerophytum gardineri, and Lobophytum
hcdleyi (?), Sphenopus marsupialis, Fungia crassitentaculata, Goniopora sp.,
Pachyseris sp., Pocillopora grandis, Turbinaria cinerascens and T. crater, Porites
arenosa, Cceloria sinensis, and other Corals ;

Hydroids — Plumidaria setacea, Monostachys dichotoma, Pasithea hexodon, Sertu-
laria (? n. sjj.);

Phyllacanthus bactdosa, Linckia biforis, Astropecten hemprichii, Pentaccros lincJci
and P. nodosus, Actinometra parvicirra, and Antedon palmata, Holothuria atra,
IT. kurti, II. monacaria, Colochirus doliolum, Col. quadrangularis and the new variety
mollis, Havelockia hcrdmani, n. gen. et sp. (Pearson) and many Ophiuroids ;

Worm tubes (Serpula, Sabella, Sec), Physcosoma asser, Panthalis melanonotus,
Tlwlepus sp., Terebella sp., Nothria sp., Lingula;

Polyzoa — many, belonging to the genera Crisia, Buskia, Amathia, ^Etea,
Alcyonidium, Cellepora, Cellaria, and Porella;

Lambrus sp., Dromia sp., Pinnotheres sp., Leucosia urania, and other Crabs ;

Pearl oysters (very few — scattered), and Modiola (in gelatinous nests), Nudi-
branchs, Ranella albivaricosa, Triton sp., Pleurotoma crispa, Turritella mactdata,
2\ Candida and another sp., Nassa rufula, N. micans and Dolabella sp. ;

Leptoelinum (several spp.); Asymmetron cingalense ; Syngnathid with dendritic
filaments.

Tow-Net gatherings taken both on the surface and at 12 fathoms, on March 7th,
showed vast quantities of diatoms — chiefly Biddulphia with some Ceratium tripos
and some small Radiolaria ; also Irichodesmium erythrceum, Sagitta and over
20 species of Copepoda, including : —

Paracalanus crassirostris, Centropages furcatus, Calanopia elliptica, Labidocera
minuta, Ectiaosoma atlanticum and E. roseum, Oithona similis, O. plumifera and
0. rigida, Corycaus obtnsus and Euterpe gracilis.

72 CEYLON PEARL OYSTER REPORT.

( )n March 8th we obtained, hi addition to most of the above:—

Calanus vulgaris, Centropages oi-snu and C. kr^yeri, Labidocera acuta, Pseudo-
diaptomus serricaudata, Acartia erythrcea, Calanopia elliptica and C minor.

On March 9th the sea-temperature at 7 A.M. was 7'J'8 F. and at 5 P.M. was
80"1° F., and the specific gravity was a shade under I "023.

In the morning we worked with the divers over the south part of the region
between the East and West Chevals. The oysters found here were mostly small
((i months old), growing in clumps or attached to the large valves of Pinna
bicolov, which is very abundant here partly imbedded in the sand (tig. 18) there
are probably about 3 or 4 to the square yard. A shoal extends from this point
(about the shoal buoy or south centre of Cheval Paar) southwards to the northern
end of Karativo Island some 10 miles awav. There is a tradition amoner the divers

X

/

, 1

//

1 /

\
I

i 1

-y

Fig. 18. Large specimen of Pinna covered in
its upper part with young pearl oysters and
in the lower part with tags of byssus, indi-
cating where oysters had been attached.

. . ■ ■ y

Fig. lit. Sketch-chart showing the shoal extending
northwards from Karativo Island to the Cheval
Paar.

that in former days Queen x\lliyaka.sam, an Amazonian princess who ruled the Tamils
in the northern part of Ceylon and personally superintended her pearl fisheries, used
to sit on the north end of the long island of Karativo and watch the divers at work
on the Cheval Paar. Karativo is now out of sight of the Cheval and there is no

NARRATIVE.

73

reason to think that the paar ever extended further south ; but the soundings along
the shoal (see fig. 19), taken along with the evidences of coast erosion that we found
at Kodramallai Point and along the shores of the Bight of Kondatcbi (see fig. 20,
showing an old cannon near the Doric, at Aripu, nearly toppled over through the

-.

X^'kH

HHHE

r

• iJMJitf ,r -

^P^^l

■

*Ife2F

^^-''.iSB

m m

Ik-' 1

. .JflHk' -'. '.-lSWEBM

i*r&&?m

Fig. 20. Captain J. Donnan, late Inspector, and Captain J. Legge, present Inspector of the Pearl
Banks, on an old cannon near the ruins of the Doric : to show the erosion of the coast in the
bight of Kondatcbi — from a photograph taken February, 1902.

washing away of the land by the sea), render it highly probable that Karativo in
former times extended northwards along the line of the shoal ; and so, possibly, the
tradition of Queen Alliyarasani is a record of the time when Karativo reached the
Cheval Paar.

On March 9th we dredged about the southern part of the Periya Paar. The first
haul was taken across the paar, and immense quantities of small oysters (about
G months old) and a bucketful of large ones (3 years old) were obtained.

The remaining three hauls (Station LV.) were outside the paar, and to the south,
and extended westwards to " out of soundings."

STATION LV. — To the west and south-west of southern end of Periya Paar ; depth
11 to 24 fathoms ; bottom sand, Nullipores and dead Corals ; dredged.

Codium bursarium, Bryopsis;

Orbitolites complanatus, Heterostegina depressa, &c. ;

Axinella tubulata, Suberites inconstans, var. digitata;

Some Corals, Antipatharia, Juncella juncea ;

Nemertine, Physcosoma agassizii, Clceia ceylonica ;

Toxopneustes pileolus, Cidaris metularia, Echinolampas oviformis, Lovenia elongata,
Maretia plamdata, Schizaster sp. ; Stichopms variegatus ;

Balanus sp., various Macrura, Lambrus sp., and other Crabs ;

L

74 CEYLON PEARL OYSTER REPORT.

Pearl oysters (both large and small), Modiola sp. (in gelatinous nests), Murex
tenuispina, Melibe sp., Doridium sp., Hexabranchus sp., and small Octopods.

On March 10th we had a long day of dredging (17 successful hauls) on and outside
Dutch Modragam, Karativo, and Col. Hamilton's Alentura paars, all lying outside
the northern part of Karativo Island.

The hauls may be grouped into three stations (LVI. to LVIIL).

STATION LVI. — West of Kodramallai Point, about 10 miles off shore, on and around
Dutch Modragam Paar ; depth 8 to 9 fathoms ; bottom coarse quartz sand,
with red weed {Hypnea musciformis, &c.) in places on which were immense
quantities of pearl-oyster spat ; 4 hauls of dredge.

Virgularia sp. (several) ;

Laganum depressum, Echinodiscus auritus ;

Sipunculus sp., Hermione ridgewayi, n. sp., Lepidonotus carinulatus, Ghlosia
ceylonica, Sabella plueotccnia, Sigalion mathildce ;

Leucosia sp. , and other small Crabs ;

Pearl oysters (young, 6 months old), Aplysia sp. ; Asymmetron cingalense.

STATION LVII. — To the west of last station, outside Dutch Modragam Paar;
11^ to 36 fathoms; bottom Orbitolites sand, Nullipores and dead Corals;
5 hauls of dredge.

Orbitolites complanatus, Heterostegina depressa ;

Petrosia testudinaria and other sponges ;

Stephanoseris rousseaui (with Gephyreans), Pennatulids, Gorgonids, and Reef
Corals ;

Phyllacanthus imperialis, Laganum depressum, Clypeaster humilis, Fibtdaria volva,
Actinometra parvicirra, Antedon bella and A. milberti;

Nemertines, Aspidosiphon sp., Sigalion mathildce (in Coral), Elasmopus sub-
carinatus, and other Amphipods ; Isocardia sp. and Dorioi^sis sp.

STATION LVIIL — Further south than last Station, on and outside Karativo Paar
and the adjacent Colonel Hamilton's Alentura Paar ; depths mainly 9 to 26
fathoms, but once or twice the dredge may have slipped into deeper water— we
were close to "out of soundings" ; bottom Orbitolites sand, and some Nullipore
and Coral fragments ; 8 hauls of the dredge.

Orbitolites complanatus, Heterostegina depressa, Rotalia ealcar, Alveolina boscii;

Various sponges ;

Gorgonia sp., Juncella juncea, Sphenopus marsupialis, Corals (from living reef);

Antedon sp., Holothuria atra, Stichopus chloronotus, var. fuscus ;

HyalincBcia sp., Distomum sp. (on gills of pearl oyster), Stylochus sp. ;

Lysianassa (? n. sp.), Lcptophoxus uncirostratus, Elasmopus subcarinatus, and a
new species of Lambos ;

NAREATIVE. 75

Pearl oysters (a few old and young), and Avicula vexillum ;

Ascidia-like Clavelinid, Branchiostoma lanceolatum, var. belcheri (several).

A tow-netting taken below the surface, at 6 to 10 fathoms, gave amongst other
things a large new Ostracod, a new species of Centropages, Mecynocera clausi,
Metacalanus aurivillii, Oithona plumifera, Clausocalanus furcatus, and Pseudo-
diaptomus serricaudatus — over 20 species of Copepoda.

On March 10th, at 7 a.m., south of Cheval, the sea-temperature was 79'8° F. ; on
the 11th, at 6.30 a.m., off north end of Karativo Island, it was 80° F., and at 6 p.m.,
on Periya Paar, it was 81'1° F., the specific gravity as usual being about 1'023.

On March 11th, we continued dredging amongst the smaller paars to the south ot
the Cheval district and lying outside Karativo Island. The 9 hauls may be grouped
in two sets, as follows : —

STATION LIX. — On and around Donnan's Muttuvaratu Paar ; in shallow water,
6^ to 9 fathoms ; bottom Nullipore and dead Coral fragments ; 5 hauls of dredge.

Tetractinellids, and other sponges ;

Madrepora (spp.) and other living Corals, Sarcophytum sp. and Sclerophytum
densum ;

Clypeaster (young), Culdta schmideliana ;

Palmyra aurifera, Stylarioides parmatus, Lepidonotus carinulatus, Eunice
teretiuscula, Ammochares sp., Sabella pJueotcenia, Elsia indica ;

An Ascomyzontid Copepod which will require a new genus ;

Pearl oysters, Doris sp. , Casella sp. , and a number of small Octopods.

STATION LX. — Outside Donnan's Paar ; in deeper water, 20 to 30 fathoms ; bottom
Orbitolites sand, a little Nullipore and dead Coral ; 4 hauls of dredge.

Orbitolites compkmatus, and other Foraminifera ;

Raspailia thurstoni, and other sponges ;

Pennatulids, Umbellula and other Alcyonaria, Sphenopus marsupialis, and some
living Corals, Antipatharia ;

Phyllacanthus baculosa, Astropecten poly acanthus, Culcita schmideliana, Nardoa
tuberculata, Ophiocoma scolopendrina, Cucumaria tricolor ;

Various Molluscan shells (undetermined) and some Nudibranchs (Doriojisis).

A Tow-netting taken at the same time gave : — Amongst 28 species of Copepoda,
Pontella securifer, Calocalanus pavo, Oithona plumifera and Candacia ethiopica.

We now returned, northwards, to the Periya Paar in order to investigate its
condition more thoroughly, as it was evidently the deepest and furthest seawards of
the paars where oysters in any quantity were to be found. It was also by far the
most extensive area covered with young oysters, and yet its past history has shown
that it cannot be relied upon to yield fisheries. Again and again it has been reported
as covered with young oysters, again and again they have all disappeared.

L 2

76 CEYLON PEARL OYSTER REPORT.

Captain Donnan in his forty years' experience has only had one fishery on the
Periya Paar — the only one to his knowledge (he told us) that had ever occurred. It
lias frequently, at an inspection, been found to have abundance of newly deposited
small oysters, while at the next inspection these oysters have gone and a fresh deposit
of younger ones may be in their place. Occasionally a few may have remained for
a second year, but they have always disappeared before becoming large enough to fish,
except in the one case of the fishery in 1879 — and even that was of limited extent
and only involved a small part of the bank.

The shallow-water plateau round the coast in the northern part of the Gulf of
Manaar, upon which the pearl-oyster paars are placed, can usually be distinguished
very clearly by the navigator on account of the difference in the tint of water. Even
20 miles from shore, in fine weather, the yellow sandy bottom shows up through the
clear water, and the slope is so steep that there is an abrupt change from the dark blue
of the deep ocean " out of soundings " to the lighter tint of the plateau. I am told that
captains who know the district, making for the Pamban Pass, know it is useless to take
soundings for the banks until the lighter coloured water is reached ; and the line of
junction is usually sharply marked.

Now the Periya Paar is close to the edge of the plateau, about 18 miles from land
and at a depth of 8 to 10 fathoms (fig. 21). It runs for about 11 nautical miles north
and south, and varies from 1 to 2 miles in breadth, and this — for a paar — large extent of
ground has been called by the natives the " mother-paar " under the impression that
the young oysters, that come and go in fabulous numbers, arise there and migrate or
are carried inwards to supply the inshore paars with their populations. During a
careful investigation of the Periya Paar and its surroundings we satisfied ourselves
that there is no basis of fact for this belief, and it became clear to us that the
successive broods on the Periya Paar, amounting probably within the last quarter
century alone to many millions of millions of pearl oysters, which if they had been
saved would have constituted enormous fisheries, have all been overwhelmed by
natural causes, due mainly to the configuration of the ground and its exposure to the
south-west monsoon.

The following table shows in brief the history of the Periya Paar for the last
twenty-four years : —

February, 1880. .

Abundance of young oysters.

March, 1882. . .

No oysters on the bank

March, 1883. . .

Abundance of young oysters, 6 to 9 months old.

March, 1884. . .

Oysters still on bank, mixed with others 3 months old.

NAREATIVE.

77

March, 1885. . .

i

Older oysters gone and very few of the younger remaining.

March, 1886. . .

No oysters on bank.

November, 1887 .

Abundance of young oysters, 2 to 3 months old.

November, 1888 .

Oysters of last year gone and new lot come, 3 to 6 months old.

November, 1889 .

Oysters of last year gone ; a few patches present of 3 months old.

March, 1892. . .

No oysters on the bank.

March, 1893. . .

Abundance of oysters of 6 months old.

March, 1894. . .

No oysters on the bank.

March, 1895. . .

No oysters on the bank.

March, 1896. . .

Abundance of young oysters, 3 to 6 months old.

March, 1897. . .

No oysters present.

March, 1898. . .

No oysters present.

March, 1899. . .

Abundance of oysters, 3 to 6 months old.

March, 1900. . .

Abundance of oysters, 3 to 6 months old ; none of last year's remaining.

March, 1901. . .

Oysters present of 12 to 18 months of age, but not so numerous as in preceding
year.

March, 1902. . .

Young oysters abundant, 2 to 3 months old. Only a few small patches of older
oysters (2 to 2| years) remaining.

November, 1902 .

All the oysters gone.

It is shown by the above that since 1880 the bank has been naturally re-stocked
with young oysters at least 11 times without yielding a fishery.

The 10-fathom line skirts the western edge of the paar and the 100-fathom line is
not far outside it (fig. 21). An examination of the great slope beyond is sufficient to

78 CEYLON PEARL OYSTER REPORT.

show that the south-west monsoon running up towards the Bay of Bengal for
6 months in the year must produce a current which will beat with full force on the

Sea.

Level ' ' ' ' ■ — ' i , F=-*-

S Periva. Pc

'2.0

Doric

Periyl FW C>\e»al P»*r

We it East

/i3^ -fa-CWi.

Fig. 21. Section across the sea from the Doric at Aripu westwards through the Cheval and Periya
paars into deep water. Horizontal scale, \ inch = 1 mile; vertical scale, \ inch = 10 fathoms.

exposed seaward edge of the bank and cause great disturbance of the bottom.
Figure 21 shows diagrammatical!}' the sudden change in slope outside the paar.

In our previous hauls on the Periya Paar we had found very large numbers of
young oysters, and wishing to ascertain how extensive the bed was, on March 12th
we steamed in the " Serendib" to the northern extremity of the paar and then south
for over 6 miles along its length, diving at intervals. We have the details of
18 dives recorded, and all of them except two give "small pearl oysters in abundance."
We were convinced both from this day's work and our previous experiences when
dredging that the Periya Paar was covered in March 1902 over the greater part of
its extent with enormous quantities of young oysters. Now the area of the paar we
take to be, from Captain Donnan's charts and our own observations, about 16 square
miles, and we estimated at the time that the oysters were so closely placed that the
bank must have held not less than about a hundred thousand millions. In the
preliminary Report to the Colonial Government, written in July, 1902, I gave this
rough estimate and stated my belief that these young oysters were doomed to
destruction and ought to be removed at the earliest opportunity to a safer locality
further inshore. Mr. Hornell was authorised by the Government of Ceylon to carry

NARRATIVE. 79

out this recommendation, and went to the Periya Paar early in November with boats
and appliances suitable for the work, but found that he had arrived too late. The
south-west monsoon had intervened, the bed had apparently been swept clean, and
the enormous population of young oysters which we had seen in March, and which
might have been used to stock many of the smaller inshore paars, was now in all
probability either buried in sand or carried down the steep declivity into the deep
water outside. This experience, taken along with what we know of the past history
of the bank as revealed by the Inspectors' reports, shows that whenever young
oysters are found on the Periya Paar, they ought without delay to be dredged up in
bulk and transplanted to suitable ground in the Cheval district — the region where the
most reliable paars are placed.

From this example of the Periya Paar it is clear that in considering the vicissitudes
of the pearl-oyster banks we have to deal with great natural influences which cannot
be removed, but which may to some extent be avoided, and that consequently it is
necessary to introduce large measures of cultivation and regulation in order to
increase the adult population on the grounds, give greater constancy to the supply,
and remove the disappointing fluctuations in the fishery. The depth of water at the
spots where our divers went down on the Periya Paar varied from 9 to 12 fathoms,
the bottom is hard, so-called "rock," in most parts; in some places the flat "rock" is
covered by a thin layer of coarse quartz sand. A certain amount of dead shells,
bored by Gastropods, occurred, and a good many "Oorie" were brought up. Some
coral fragments were found in places, and a few other animals, Terebellids in sandy
tubes, and small fish (Gymnapistus niger), &c, were obtained.

The sea-temperature on the Periya Paar at 7 a.m. was 80-3° F., and in the evening
(6 p.m.) on the Periya Paar Kerrai, much further inshore and north of the Cheval, it
was 82° F., the specific gravity on both being 1"023.

We then, on March 12th, had 4 hauls of the dredge off the northern end of the
Periya Paar to the west and south-west. These may be united as —

STATION LXI. — To the west and south-west of northern end of Periya Paar; 12 to
14 fathoms ; bottom sand, Nullipore and Coral, with Sargasso weed.

AxineUa tubulata and A. donnani, Petrosia testudinaria ;

Heterocyathus aequicostatus (with Gephyrea) and other Corals ;

Physcosoma scolop>s (in AxineUa tubulata), Nicomache sp., Gastrolepidia clavigera;

Phyllidiella sp. ; Asymmetron (Heteroplewon) cingalense.

The Tow-Net at the same time gave some Copepoda, including PonieUopsis strenua
and Corycaus gracilicaudatus.

On March 13th the day was spent in dredging from Periya Paar Kerrai westwards,
across Periya Paar and outwards to the west and south into deep water. Thirteen
hauls were taken, which may be grouped as two Stations —

80 CEYLON PEARL OYSTER REPORT.

STATION LXII. — Between Periya Paar Kerrai and Periya Paar, working westward ;
depth 7 to 13 fathoms ; bottom coarse quartz sand, some Orbitolites sand and
Nullipores. Three hauls of dredge.

Orbitolites complanatus, and other large Foraminifera ;

Choetopterus appendiculatus, Sabellaria bicornis, Filograna sp., a tube-building
Amphipod {Cera/pus sp.) ;

Echinostrephus molare, Echinodiscus auritus, Stichopus chloronotus ;

Craspedochiton laqueatus (several), Pearl Oysters (small very abundant), " Suran,"
Ostrea sp. , Venus sp. , Murex sp. , Ficus ficoides ;

Molgulids, flat Polystyelid colony (on oyster shell) ;

Branchiostoma belcheri (11 specimens), " Sand-eels" (Trichonotus sp.).

STATION LXIII. — To the west of Periya Paar, going south ; depths 17 to 55 fathoms
(we sounded in 80 fathoms when the dredge was put over for one haul, but it
is doubtful whether the dredge touched the bottom before we drifted in to about
40 fathoms) ; bottom Orbitolites sand, some dead Coral, shells and pieces of
Nullipore. Amongst the animals were : —

Orbitolites complanatus, Heterostegina depressa ;

Ciocalypta tyleri, var. manaarensis, Spirastrella sp., and other sponges ;

Heteropsammia michelini (orange), with Gephyreans, Flabellum rubrum*
Dendrophyllia sp., Juncella (? n. sp.), Pteroeides sp. ;

Actinometra parvicirra, and another species, Salmacis dussumieri, Clypeaster
scutiformis, Lovenia elongata, Echinolampas oviformis, Fibularia volva, Echi-
noneus cyclostomus, Pectinura gorgonia, Op/dopteron elegans, Astropecten poly-
acanthus ;

Chlceia sp. , Serpida sp. ; Hippa, Thia, and other Crabs ;

Polyzoa — Lepralia edax, and L. robusta, and species of the genera Scrupocellaria,
Adeona, Gemellipora, Schizoporella, Membranipora, Microporella, Boiverbankia and
Ascopodaria ;

Mollusca — including, Mitra crebulirata, M. militaris, Cerithium armatum,
C. citrinum, Strombus pidchellus, Natica albiimen, Pleurotoma tigrina, Nassa sp.,
and Dentalium sp. ; Molgulids.

The sea-temperature at 7 a.m. on the west of the Periya Paar Kerrai was 81° F.,
and at 6 p.m. on the Vankali Paar was 82°-l F., the specific gravity as usual
being 1-023.

We tow-netted during the day, and obtained on the surface numerous deep blue
Copepoda (Labidocera acuta) a deep blue Porpita and colonies of Compound Radiolaria
(Collozoum sp.) with black pigmented individuals, also Erich thus and other larval

* Mr. SrANLEY Gardiner informs me that this belongs to the " facies " or variety which has the form
known formerly under the name F. stokesi (Ed. and H.). See Gardiner ' Mar. Invests, in S. Africa,'
p. 117, 1902.

NARRATIVE. 81

Crustacea and much Trichodesmium erythrceum. Twenty-four species of < lopepoda
have already been identified by Mr. Andrew Scott from this hauL

The deep Tow-net brought up Sagitta, a violet Appendicularian, filamentous Algse
forming balls, a large new Ostracod, and 15 species of Copepoda including Clauso-
calanus furcatus and Ectinosoma atlanticum.

In the evening, at 9 P.M., the sea was dotted with bright phosphorescent lights of
considerable size singly placed at some distance apart. These for over an hour
continued to glow with a pulsating appearance in harmony — all shining brightly at
the same moment, and then all flickering out together, to re-appear simultaneously a
few seconds later. We went out at once with a net and obtained a sample of the
plankton, but could not be sure that we had caught any of the pulsating forms. The
gathering contained Sagitta (very many), Appendictdaria, Copepoda— half-a-dozen
common species and Sapphirkina sinuicauda, Pontella fera, Calocalaniis pavo and
some smaller forms, along with half a-dozen one-inch-long Heteronereids of a reddish-
brown colour. We suspected the light to be due to the last-named, and if that is so,
possibly the periodicity was a result of the epitocous condition and was accompanied
by a simultaneous discharge of genital products.

On March 14th, at 7 AM., at the southern end of Pamban Pass, the sea-temperature
was 820,5 F. (5 degrees higher than it was at the same spot on February 5th) ami
the specific gravity was 1"022. At 6 p.m. in Palk Bay, the sea-temperature was
again 82°'5 F. (4^- degrees higher than on February 6th) and the specific gravity
was 1 '02 1. We anchored for a couple of hours one mile off the village of Rameswaram
and lauded in the boat, examining the beach, the coral shoals on the way in, and the
raised coral platform along the shore alluded to by Thurston ('Notes on the Pearl
and Chank Fisheries, &c.,' Madras Museum, 1890).

Two long hauls of the large shrimp-trawl were now taken in Palk Bay on the way
across to Jaffna. The first was over the same region trawled on February 6th
(Station XVIII.), but at right angles to our former course (see fig. 22). Starting due
east of Rameswaram, about 4|- miles off shore at a depth of 5 fathoms, we towed for
about 10 miles to the north-east, towards the island of Catchetivo, the water deepening
gradually to 7 fathoms. The bottom was soft grey-blue mud, containing small
concretionary nodules and many casts of the interior of Gastropod shells. The
animals obtained were mostly the same fish and invertebrates as on February 6th, a
few small Crabs, Molluscs and Echinids ; also a species of Arcania with large lateral
projections of a deep violet colour on the carapace. Several pearl ovsters were
obtained in this haul, and a sea-snake.

The second haul was taken to the south-east of Catchetivo Island, in a depth of
7 fathoms. The trawl was worked rather more rapidly with the result that it did
not hug the bottom so closely, and brought up no mud and very few invertebrates,
but a large haul of small Scopelid fishes which filled half-a-dozen ship's buckets and
numbered over 2500 specimens. They apparently belonged to only 3 or 4 species

M

Fig. 22. Sketch-map of Gulf of Manaar and Palk Bay, showing Stations I. to XIX. and XLVII. to
LXIX. The course of the first cruise is shown by the dotted lines with arrows. The stations
of the second cruise arc surrounded by dot-and-dash lines.

NARRATIVE. 83

(Saurus indicus, S. myops and Saurida tumbil), all of silvery aspect. The trawl also
contained 6 sea-snakes, 2 small Octopods [Polypus granulatus and another species),
and 6 or 7 very fine prawns (Penmis sp. ).

On March 15th we lay at anchor off Jaffna, taking in supplies and arranging for
Sir William Twynam to join our party. At 8 a.m. the sea-temperature was 82°-8 F.
and the specific gravity 1'021 ; at 8 p.m. hoth readings were the same.

On March 16th we trawled in the northern part of Palk Bay, down the broad
passage between the islands from Mandativo to Delft Island at depths increasing
gradually from 4^ fathoms outwards to 8. About 12 miles were covered in 3 hauls,
the first southwards from off Mandativo towards Kakerativo ; the second frorn east to
west about 2 miles north of Kakerativo, depth 7 fathoms ; and the third half-way
between Kakerativo and Delft Island, depth 8 fathoms. The last haul was on the
mud with concretions, as at Station XVIII. (March 14th), but the two previous ones
were on sand and shells with some living Coral. I consider all this day's work as
being one locality (see fig. 22).

STATION XIX.— In north part of Palk Bay, east of Delft Island ; depth 4| to
8 fathoms ; bottom sand and shells to mud ; sea-temperature, 7 A.M. off Mandativo
Island 82-8° F., 5 p.m. off Jaffna 84° F., specific gravity in both localities 1-020 ;
3 hauls of the large shrimp-trawl.

Various sponges ;

Medusa? [Nausithoe, &c), Turbinaria cinerascens and other Corals;

Some Amphipods, Erichthus, Phyllosoma, Prawns and Crabs ;

Area tortuosa, A. compacta, A. tetragona (?), A. virescens (?), Mytilus barbatus,
Cerithkim citrinum, Mitra pyramid alis (?) and other shells, and Octopods [Polypus) ;

A number of Polyzoa belonging to the genera, Bugula, Cellepora, Lepvalia,
Schizoporella, Smittia and Crisia ;

Leptoclinum (2 species), Khabdocynthia sp., Rhodosoma sp., Polycarpa sp., and
Salpa runcinata-fusifurmis (large, many) ;

Small Sole (Solea ocidus).

On the way back to Jaffna to pick up Sir William Twynam, we anchored for a
couple of hours on the edge of the large shoal lying south and east of the Island of
Punkudutivo (marked on the chart " Pearl beds ") and went off in the boat to examine
the coral reef and see if any trace could be found of the pearl-oysters said to have
formerly existed there. We expected from the chart to have to row for at least a
mile before coming to the reef, but in a couple of hundred yards progress was
stopped by coral growing to within a foot or so of the surface, and on trying
several other passages inwards to the land all were found blocked by luxuriant coral
growth. We had then to leave the boat and wade over the coral plateau on
the tops of enormous branched Madrepores and other flattened expanded colonies (the
largest I saw anywhere round Ceylon) which crushed and snapped under one's weight

M 2

84 CEYLON PEARL OYSTER REPORT.

and occasionally gave way altogether, letting one down into a hole with much
laceration of skin on legs and arms. No traces of pearl oysters were seen, but possibly
we were not able to get far enough inshore. On returning to the ship we found she
had shifted her position, as on swinging round to her anchor in what according to the
chart was 3 fathoms of water, she hit the rudder against the edge of a mass of
growing coral reaching to within a couple of feet of the surface. The officers, from
the deck, had fished up several large pieces of colonies for me with boat-hooks.
It is evident that the coral reef is extending rapidly at this spot. It must not be
supposed that a coral reef once it is surveyed remains stationary. Under some
conditions it may become reduced in size, and under others it may show rapid
growth both horizontally and vertically. The most abundant forms we obtained
were : — Madrepora cervicorms and several other allied species, PociIlopor<t grandis
and P. ccBspitosa, Pontes pcdmata, several species of Montipora, and various
Astrreids.

On March 17th in Pamban Pass at 7 a.m., the sea-temperature was 82° F., and
the specific gravity 1'020G ; at G P.M., on Kallatidel Paar, the temperature was
827° F. aad the specific gravity V023. After rejoining Captain Donnan and the
inspection boats in the South Cheval district, we took 4 hauls of the dredge between
the South Modragam Paar and Kodramallai Point. These may be united as : —

STATION LXIV. — From between South Modragam and Jaggerboom paars along a
line south-east towards Kodramallai Point ; depth Ah to 5^ fathoms ; bottom
coarse sand, with much fine green-weed and small pearl oysters.

Some Renierid sponges ;

Lytu.carpus (( n. sp.), Carnpanularia juncea, Fungia dentata (many), large
solitary Corals, and some Pennatulids ;

Echinasier purpureus, Pentaceros lincki and P. nodosus, and many Ophiuroids ;

Chloda sp., Ilarmothoe imbiicata ;

Many Amphipoda including a new species of Lambos, Lysianassa (? n. sp.) and a
remarkable new species of Leptochelia with immense chelas considerably longer than
the body ;

Craspedochiton laqueafois, Margaritifera vulgaris (many small), Turbinella rapa
(large), Pleurotoma cremdata, Nassa reticosa, Pteroccras sp., Vertagus uluco,
Vermctus sp., Lamellctria sp., TJolabcUa sp., Aplustrum (hahtssiarc/ti.

The fine green-weed from the bottom had very young spat of pearl oysters on it.
The small oysters dredged were about 8 or 9 months old, and were in quantity at
about 3^ miles off Kodramallai Point. A tow-netting on March 17th gave us a new
species of Centropages with a prominent dorsal spine.

On March 18th the sea-temperature on Kallatidel Paar, at 7 A.M., was 82-2° F.,
and on Cheval Paar, at 6 P.M., was 827° F.

In the morning I visited Aripu Coral Peef in one of the boats, and waded over

x.\i;i; ativjv s:.

parts of it. It was very rich zoologically, the eoral growth being exceedingly luxuriant.
The most prevalent forms were : — several species of Mddrcpora, Mohtipord,
Turbinaria, Goniastrakt, Favia and Poritks. Large Cyprcea tigris, large Ascidia sp.,
a pinkish Rhabdocynthia , Cynthia sp., Euryfhoe latissim'a, E. hngicirra, Notodirus

triyonoccphalus, and some Holothurians (including Holothuria moiuu-ariu) were
amongst the other conspicuous forms collected.

Tn the afternoon we dredged round the shoal buoy at the south end of the
Cheval Paar, and in a north -westerly direction.

STATION LXV— From shoal buoy up West Cheval Paar; depth 1\ to 8 fathoms ;
bottom white quartz sand ; 4 hauls of di'edge.

Campanula-rid- juncea ; Pseudoboletia sp. ;

Hi/ale nilssoni (variety), Pisa sp. (many) and other Crabs ;

A few adult and very many young Pearl Oysters, Doris sp., Aplysia (green coloured) ;

Branchiostoma lanceolata, var. belchen ((.) specimens), and the long worm-like
fish Opichthys timorensis.

On March 19th, at 6.30 a.m., on the south-east of Cheval the sea-temperature was
82'5° F., and at 7 p.m. it was 83'5° F. The day was spent in dredging down the
coast from Donnan's Muttuvaratu Paar (Station LXVI.) through Mudalaikuli Paar
and Talaivillu Paar (Station LXVII.) to Coppeluddi and Navakaddu Paar (Station
LXVIIL). Eight hauls were taken, grouped in three stations.

STATION LXVL— From south of Donnan's Muttuvaratu Paar along the west of
the northern part of Mutwal Island as far as off Mudalaikuli Paar; depths 10
to 35 fathoms; bottom Nullipore and < )rl)itolites sand, some red Algae and dead
Coral ; three hauls of dredge.
Orbital ites complanata, Alveolina boseii ;

Tetilla poculifera, n. sp. (Dendy), Stelletta sp., a Calcisponge and others.
Halicornaria setosa, Sarcophytum, Pennatulids and other Alcyonaria, Flabellum sp.,
Heteracyathus wquicostatus (with Gephyreans), and living Madrepores ;

Phyllodoce foliosopapillata and Mystides sp. (afterwards found in our pearl-oyster
cages at Galle, and may have come from this paar), Aspidosiphon corallicokt ;
Anfedon palmata (?), Holothuria atra and //. kurti, Cucumaria imbricata ;
Mcera rubromdeulata ;

Terebra sp., Pteroceras sp., Phyllidia nigra and small Octopods (Polypus sp.) ;
Cynthia dura (?), C. sp.. Pulycarpa sp., Leptoclinum sp.

STATION LXVII.— On and off Talaivillu Paar, off south end of Mutwal Island;
depth 10 to 14 fathoms; bottom dead Coral and Nullipore; 2 hauls of dredge;
Halimeda tuna, Padina commerssonii. No Pearl Oysters.
Various sponges, chiefly Tetractinellids ; Stephanoseris rousscnui and Het&ro-

8fi CEYLON PEARL OYSTER REPORT.

psammia michelini (with Gephyreans), Ckvryophyllia sp., Lobophytum pauciflorum,
Sclerophytum (? n. sp.), and Alcyonium pachycladis ;

Hermione sp. and other Annelids ; Asterina cepheus and Echinanthus sp. ;

Dexamine sp. and other Amphipods ;

Vertagos pharos, and various undetermined Molluscs ;

Branchiostoma lanceolatum, var. belcheri (several) and Rhodosoma (? papillosum).

STATION LXVIIL— From off Coppeluddi southwards to Navakaddu Paar ; depth 8
to 18-g- fathoms; bottom Nullipores (Lithothamnion fruticuloswni), Coral and
muddy Orbitolites sand ; three hauls of dredge.

Orbitolites complanatus and other Foraminifera ;

Aidetta aurantiaca, Axinella tubulata;

Various living Corals — Cceloria sp., Madrepora (sev. spp.), Fungia crassitentaculata,
Flabellum sp. ;

Colochirus sp. (?) ;

Pagurids and various small Crabs ;

Molluscan shells (undetermined), Doris sp. (with black branchiae).

A Tow-net gathering yielded many Copepoda of a bluish colour, including
Pontellopsis armatus, Pontellina plumata, Labidocera kroyeri and L. acuta.

On March 20th Mr. Hornell and I were on our way back to Colombo, on the
" Lady Havelock," with a cargo of oysters for Galle. We dredged at two points, (l)
on the north end of Chilaw Paar, just north of Station V., and (2) off Negombo. At
the latter spot we were again on the bed of oysters we had found on January 31st
(Station I.) and obtained some young (about 6 months) on a bottom of coarse yellow
sand containing Cavlerpa plumaris and Halophila ovata. At the Chilaw Paar
locality we had three hauls which are united as —

STATION LXIX.— On and to the east of the north end of Chilaw Paar ; depth 8 to
1 1 fathoms ; bottom yellow quartz sand, with some Coral fragments. Yellow
Algfe with Oyster-spat ; dredged.

Heterocyathus cequicostatus (with Gephyreans) ;

Echinodiscus auritus, Clypeaster humilis, Actinometra sp. (deep olive-brown with
yellow tips to pinnae, harbouring an olive-brown Alpheus striped with grey) ;

Aspidosiphon corallicola, Lumbriconereids and other Worms ;

Balanus sp. , Amphipods and some Decapoda ;

Large and small Pearl Oysters and some other common Lamellibranchs, gelatinous
Nudibranchs {Melibe fimhriatd) ;

Large colony of a reddish Polystyelid, many Leptoclinids (white and drab),
Branchiostoma lanceolatum, var. belcheri (numerous).

A Tow-netting at the same locality gave us, amongst other Copepoda, the large

NARRATIVE. 87

blue Pontella princeps and P. securifer, Pontellopsis armatus and Labidocera
kroy&ri.

We reached Colombo at 4.30 p.m., and this brought to an end the second cruise of
the " Lady Havelock," which had lasted for three weeks and four days. We had
left Captain Donnan before the end of his inspection of the banks, because now that
I had seen all possible spots on the coast which might serve for a biological
laboratory and had selected Galle as being unquestionably the best, it seemed
desirable — as the result of correspondence with the Lieutenant-Governor — that I
should see for myself the several quarters at Galle that had been proposed and plan
out with Mr. Hornell the necessary alterations and fittings. We took with us
various samples of living oysters, both large (3 years old) and small (about 6 months)
which were conveyed safely from the pearl banks to Colombo in our steamer tanks
and from Colombo to Galle by train in large earthenware "chatties" of sea- water.
The journey occupied, with our necessary stoppages, four complete days at a very hot
time of year. We were, however, able at the end of it to deposit most of these
oysters in a living condition in the sea at Galle on the evening of March 22nd. They
soon recovered activity, and were found next morning to be climbing up the chatties
and on the netting in which we had enclosed them. The next three days were spent
at Galle in examining, along with Mr. H. W. F. C. Brodhurst, the Government Agent,
and Mr. T. Twynam, the Master Attendant, certain offices and bungalows in the Fort,
in the native Bazaar and near Bayley's Villa on Glosenburg (see fig. 7, p. 46). Not-
withstanding Professor Haeckel's favourable opinion of the last named as a site,
given 20 years ago, we found it necessary to reject that end of the bay in favour of
the Fort ; and in the end for several reasons, which I reported to the Lieutenant-
Governor, a portion of the former Military Hospital conveniently situated on the
ramparts at Akersloot or Sailors' Bastion, close to a good supply of clean sea-water,
was selected as being the locality best fitted for adaptation as a marine laboratory
(fig. 25). This report was acted on soon after I left Ceylon, with the result
that Mr. Hornell, upon his return from the pearl-banks in April with a further
supply of oysters, was very soon established in a simple but efficient laboratory at
Galle — carrying on the work I had left in his hands. Since then Mr. Hornell has,
by fortnightly letters, and frequent longer reports, drawings and specimens, kept me
in close touch with all the details of his work ; and I have sent him what information
and instructions were necessary from time to time. The results of these observations
at the Galle Laboratory will be given in the later parts of this report.

After having settled matters at Galle so far as was then possible, and having
deposited our pearl oysters in bags and baskets suspended from buoys and spars anchored
out in the bay (fig. 23), Mr. Hornell and I returned to Colombo late on March 25th.
The following day was occupied in seeing the Lieutenant-Governor in regard to the
laboratory at Galle, and other business, and in packing and despatching some of the
collections. Early in the morning of the 27th we started by coach to Chilaw, whence

88

CEYLON PEARL OYKTKK REPORT.

we went on by small boat next day to join the "Serendib," which was sent down the
coast by Captain Donna N to meet us. I had now only about ten days left in Ceylon
and was anxious to spend most of that time on board the inspection barque seeing

Fig. 23. Experimental oyster cages moored in Galle Bay.

the divers at work and following their results day by day. We reached the
" Kangasameeporawee " on the Muttuvaratu Paar in the evening of the 28th, and
rejoined Captains Donnan and Legge and Sir W. Twynam. On the 29th March
we were working on Donnan's Muttuvaratu Paar all day. There were plenty of
oysters, and the divers brought us up samples and other specimens enough to keep
all hands busy. Amongst other interesting forms found here was a new species of
Chitonidse, Ischnochiton ravance, n. sp. We had now re-started all the tanks and
tubs and had many experiments under observation. The paar was estimated to have
about 277,000,000 of oysters between \l and 2i years old, but cpiite a number of
them, in the samples we examined, were found to have a dwarfed or ill-grown
appearance, accompanied by a yellow discoloration of the mantle and other tissues..
We carefully examined this yellow and stunted condition of these oysters both at the
time and since, and shall discuss it later on in the report. A good deal of our time
was now occupied in examining the food in the stomachs and the sexual condition of
the oysters (fig. 24 shows our work place on the barque). We also took tow-net
gatherings and obtained samples of the bottom and the bottom fauna by means of
the divers, but we had no further dredging or trawling.

The Tow-NET on March 2'Jth, over Donnan's Paar, yielded Trichoi/esmium, Sagitta.

XAKKATIYK.

89

Pteropods, and 35 species of Copepoda including — Corycceus venvstus and C. speciosus,
Qlytemnesfra Scutellaria, Kctiuosoma roseitm, Acdrtia erytlrrcta, Onccect mediterranean

Fig. 24. The deck laboratory on the " Rangasameeporawee," from a photograph hy J. HOENEI.L.

Rhincalanus comutus, Euchceta marina, Eucalanus stibtenuis, Setella gracilis,
Tortanus forcipatus, Calocalanus pavo and C. plumosits. We also obtained from tins
paar a remarkable Copepod, described below (see p. 245) as the type of a new genus
Ridgeivayia, in honour of His Excellency Sir J. Wkst Rtdgeway, Governor of Ceylon
at the time of these investigations.

The sea-temperature on March 29th at 5.30 p.m. was 84° F., and specific gravity
was 1*023. The temperature in our wooden tanks on board at the same time was
83° F., and we generally managed, by covering the tanks with moist canvas, to keep
the temperature of their contents a degree or two below that of the sea.

The weather was now very hot. On March 30th, the sea-temperature at 7 a.m.
was 84° F., and at 5 P.M. was 85° F. We now moved to the southern part of the
paar, and in the afternoon rowed to the coial reef lying off Dutch Bay, where Captain
Legoe and I waded over the reef and collected various samples of the fauna.

On March 31st the weather was still warmer. The sea-temperature was 85° F.
in the morning and 88° F. in the afternoon, but we managed to keep that in our
tanks on board down to 83°'5 F. to 84° F., and the oysters remained very healthy.
We moved this morning to the Mudalaikuli Paar, which we found to be practically a
living coral reef with no oysters. Fine coral colonies (Coeloria sinensis, Prionastrcea
sp., Pachyseris sp., Goniopora sp., Hydnophord microcoria, Galaxea sp., and Fungia
patella) and sponges (Axinella earteri, PJujllospongia holdsworthi, Spongionella
nigra) were brought up by the divers, but not a single oyster. In the afternoon we
took boat and landed at Kattanattu Point, where a long sandy spit runs out to the
north-west with a coral reef continuing onward in the same direction and others
parallel outside it, so as to give some shelter to a little bay inside the point. We

N

90 CEYLON PEARL OYSTER REPORT.

found however that the locality was quite unsuitable for oyster cultivation. In the
south-west monsoon the surf evidently breaks over the spit and without doubt
churns up the water and the bottom of the bay. This opinion was entirely corroborated
by what we heard from the natives on shore.

The Tow-netting on March 30th over the Mudalaikuli Paar gave very much the
same results as on the previous day. As additional forms obtained may be noted —

Calanopia ettiptica, Centropages orsini and a new species of Centropages, Pseudo-
diaptomus serrieaudalus, and Eucalanus monachus.

On April 1st we moved the barque to Talaivillu Paar, where again we found no
oysters, the bottom being practically a living coral reef. At 8 a.m. the sea-tempera-
ture was 86° F., and at 5.30 p.m. 87° F., and the water in our tanks 84° F. The
specific gravity was 1/0229. On Talaivillu Paar we obtained, on a brown (largely
calcareous) sand with much Halimeda (II. gracilis and H. tuna) —

Axinella donnani, various incrusting and some Tetractinellid sponges ;

Cceloria sinensis, Porites arenosa, Fungia crassitentaculata, F. patella, Madrepora
(sev. spp.), Montipora sp., Favia and other Astrseids, Flabellwn sp., Sarcophytum
roseum, and other Alcyonaria ;

Cheosiphon aspergillvm, Sabellaria bicornis;

Dexamine sp. and other Amphipods ;

Phyllidia varieosa and P. ccratosoma ; Leptoclinum sp.

The Tow-nets gave 22 species of Copepoda, amongst which may be mentioned :—

Setella gracilis, Oncoea medkerranea, Corycceus lemgistylis, Aeartia erythreea,
Pseudodiaptomus aurivillii, P. serricaudatus, and Tortanus forcipatus.

On April 2nd, at G.40 a.m., the sea-temperature was 85° F. and at 6 p.m. it was
86-5° F., the specific gravity being 1/0228. We had moved to the Navakaddu Paar,
where the usual diving operations were continued all forenoon. The bottom here
consists largely of great blocks of dead Coral much encrusted with Polyzoa, Nulli-
pores, compound Ascidians, &c, together with a certain amount of living Coral, such
as Astrseids and Porites.

Amongst other organisms brought up on Navakaddu were : — Halimeda gracilis
and various red Algse (Hypnea musciformis, Polysiphonia, &c).

Asterina eepheus and Antedon sp. (? A. palmata) ;

Chcetoptenis append iculatus, Trophonia sp.

Amphipods, Compound Ascidians, and a new species of Chitonidse, Callochiton sub-
Icevis, n. sp. (Sykes). There were no pearl oysters.

The Tow-nets this day, in addition to Triehodesmium (very abundant) and Ceratium,
contained a number of Copepoda, including Setella gracilis, Corycceus venustus,
Calanus minor, Ectinosoma atlanticum and OitJtona plmnifcra.

In the afternoon, still continuing south, we moved down upon the Udupankarai
Paar. We found that there were no oysters on the ground, and not likely to be, as
this paar, like several of the smaller ones in this neighbourhood, is now practically a

NARRATIVE.

living and growing coral reef; but from the older records it seems probable that in
Dutch or Portuguese times these ranked amongst the productive oyster banks.

On April 3rd we moved down south to the Jokkenpiddi Paar, the last I was able
to examine personally. The sea-temperature at 7 a.m. was 8 5 "5° F. We anchored
the barque on the north end, and in the " Serendib" ran south for about 7 miles and
then steamed slowly back, sending the divers down every \ mile. Most of the dives
gave a " rock " bottom with dead, and occasionally living, coral, and in several places
young oysters (3 to 6 months) in quantity; depth 8| to 10 fathoms. Amongst the
animals brought up were : —

Axinella clonnani, an abundant lilac Chalina and other sponges ;

Various Gorgonoids and common living corals ;

Echinostrephus molare (in deep burrows in coral blocks), Antedon sp. (with
commensal Alpheus comatulonun) ;

SabeUaria bicomis and other Worms ; Dromiad and other small Crabs ;

Chama foliata, and some coral-boring Lamellibranchs, Pearl Oysters, "Suran"
(Modiola) and "Oorie" (Sistrum) ; Leptoclinum sp.

At 10 p.m., on April 3rd, I had to leave the barque " Rangasameeporawee," and
was conveyed by the " Serendib" down to Colombo — as I was booked to leave Ceylon
on April 7th, and had still to discuss various matters with the Lieutenant-Governor,
transact business at the Master- Attendant's and other Government Offices in Colombo
and see to the preservation and packing of many specimens. Mr. Hornell remained
with Captain Donnan for a few days longer to complete the inspection of the southern
paars, and obtain a supply of pearl oysters of various ages to take with him to the
marine laboratory at Galle. He examined the Jokkenpiddi, Karkapanni, Chilaw,
Oolawitti and Negombo paars, and brought
a quantity of young oysters from these
banks to Colombo, where they were sus-
pended in coir baskets from the stern of
the barque lying in the harbour. He then
took the "Serendib" north to the Muttu-
varatu Paar, obtained a supply of large
oysters (3 years old), returned to Colombo,
picked up the young oysters and conveyed
the whole cargo round to Galle, where they
arrived in splendid condition, not one oyster
having died on the way. This shows the
practicability of conveying the pearl oysters,
both old and young, from place to place in a
healthy condition by the means we adopted.
Great care is, however, necessary if the temperature be high (the sea averaged
about 85° F. during our operations) and if the run be more than 3G hours without

N 2

:o--vl ■ A

MUX fift^ Foot
- S.OtKS k Coral

RAMPAgT WALL

Fig. 25. Galle Marine Biological Station, at
former Military Hospital on Akersloot or
Sailors' Bastion.

A, semi-rotary hand pump; B, aquarium shed;
C, inlet pipe from — D, coral pool ; E, suriya
tree ; F, entrance steps from Dutch gateway
dated 1759; G, overflow pipe.

02

CEYLON PEAEL OYSTER EEPORT.

a stop. On that account the November inspection would probably be a better
time for transporting, as tbe temperature is lower then than in March and April.

Fur some time alter this Mr. HoRNELL was fully occupied in looking after his
oysters sunk or suspended in bags and baskets and " chatties" from boats, and buoys
and booms in various parts of Galle Bay ; and in superintending the fitting up of the
marine laboratory at Akersloot Bastion. In addition to the large rooms (fig. 25)
obtained from the old Military Hospital, on the ramparts of the Dutch Fort, which
had to be sub-divided and furnished with work-tables, shelving and cupboards, an
outside shed formed of " cadjan" (the large leaves of the talipot palm) was erected as
a tank-house (fig. 136) to accommodate the wooden tanks and glass aquaria containing

Fii;. 26. Aquarium shed with wooden tanks at tliu Gallu Marine Biological Station.

the oysters under experiment and observation. Care was taken in the site and
construction of tliis tank-shed to make it as cool as possible, and the sides were closed
in with "tat "-blinds (split bamboos tied together), as being airier and lighter than
cadjan ilaps. The tanks were connected with the sea by a semi-rotary pump and
water pipes which were carried about 20 feet outwards from the base of the rampart
in order that the intake might be placed in a deep clear pool lined with living coral.
The reservoir into which the pump discharges and from which the sea-water runs
through the tanks is formed of two large iron tanks such as are used for citronella oil,
with their upper ends cut out, and joined by a pipe at the base. The various
observational tanks and aquaria (which had been brought out from Liverpool) were
joined up by means of glass and rubber tubing, and were provided with arrangements
devised by Mr. Hornell for distributing air in finely sub-divided bubbles throughout
the water. This marine laboratory has proved in every way satisfactory aud suitable

NARRATIVE. 93

for our work during the last year. Mr. Hornell — as the later parts of bhis report
will show — has heen able to investigate there the greater part of the matters 1 left in
his hands ; but there is still much useful work connected both with the Pearl Fisheries
and with other marine industries that he could continue to carry on in this scientific
workshop. Moreover, with a little extension of accommodation and permanent
equipment it would he an eminently desirable and well-fitted establishment for general
marine biological investigation, and would add to the scientific resources and
attractions of the Colony. As examples of this it may lie mentioned that during the
past year (I) Mr. Hornell has been able to supply specimens of marine alga? to
workers at the Peradeniya Botanical Gardens, and types of marine animals to the
Medical College at Colombo; (2) a Swedish Botanist, Dr. Nils Svedelius. from
Upsala University, has already made use of the laboratory as a place of research,
and has expressed the opinion that it is very favourably situated for a tropical
Marine Biological .Station ; and (3) it would naturally afford accommodation and
material to the other scientific men of Ceylon. It is conveniently and centrally
situated in the Fort, easy of access from the railway station and near the boat
jetty, close to pure sea-water, opposite the Vellikoko Beef, adjoining good collecting
grounds and with a living coral reef fringing the base of its walls — it seems
in short an ideal spot for the purpose. Dr. ARTHUE WlLLEY, F. U.S., Director
of the Museum at Colombo, writes to me in regard to this Galle Marine Station
(May Sth, 1903) — "I shall certainly hope to see the Laboratory which you
established at Galle made a permanent institution after the publication of your
report. ... I have been twice to Galle and have seen Hornell there hard at
work, and he has shown me the admirable though simple appliances which render
so much service."

Mr. Horxell's work at the Galle Laboratory since April, 190:!, has been chiefly on
the following points — all of importance in connection with our understanding of the
mode of life, the prosperity and the reproduction of the pearl oyster: —

1. ByssuS formation, attachment, detachment, casting off the byssus and re-attach-

ment.

2. Locomotion, both in old and young, crawling by means of the foot, and move-

ment of the shells.

3. Effect of being partially or completely buried in sand. A healthy oyster can

free itself from a thin layer of sand, and usually does so ; but it cannot get out
of 3 inches of sand and soon dies when buried.

4. The sexual condition of the oyster, the production of eggs and spermatozoa,

their emission, the fertilisation and the early stages of development.

5. The "spat" — its characters and stages, and comparison with small species of

Avicula.

94 CEYLON PEARL OYSTER REPORT.

6. Food and feeding, and the respiratory and nutritive currents of water. Varying

" condition " of different oysters.

7. Growth, increase of the shell and repair of injury.

8. Parasites — Sporozoa, Cestodes, Trematodes, Nematodes, &c, and Commensals:

their effect upon the oyster.

9. Other diseased and abnormal conditions of the oyster.
10. Pearl-production, both artificial and natural.

Some of these inquiries were merely the continuation of observations and experi-
ments we had made during our work in the " Lady Havelock," others were under-
taken with the object of settling definitely doubts that had been expressed or
difficulties that had been raised in the Inspectors' reports and other previous writings,
such as Sir W. C. Twynam's " Report on the Ceylon Pearl Fisheries," Colombo, 1900
— a most useful summary of many previous documents, illuminated by a personal
experience of nearly half a century. Our results, although no doubt they could be
added to by further work, are I believe conclusive so far as they go ; and
consequently must be recorded even when, as in some cases, they merely corroborate
or extend what was observed by Kelaart, Thomas, Holdsworth, Thurston or
others.

The powers of locomotion we found to be unexpectedly great, especially in the case
of young oysters (see some instances we gave on p. 58) ; and the capability of
detachment and re-attachment, and of renewed byssus-formation, is considerable.
These are clearly points of great practical importance in connection with our recom-
mendations as to the thinning out and transplanting of young pearl oysters. Such
transplantation could only be successfully undertaken in the case of oysters able to
find suitable stations in their new environment and to re-attach themselves securely.
The effect of burying in sand throws light upon some of the catastrophes that have
affected promising beds of oysters in the past, and the knowledge will be useful in
leading us to remove the stock in dangerous positions from such risks in the future.
The sexes are separate, and, as our experiments show, remain the same from
season to season : each individual is permanently either male or female. The natural
emission of both ova and spermatozoa has taken place in our tanks at the Galle
Laboratory, and we have reared the young pearl-oyster from the egg to a shelled
larval stage similar to one obtained in the tow-nets. On all the other points we have
I believe made some additions to knowledge which will be discussed below in the
special articles.

In October, 1902, Mr. Hornell carried out my suggestion of a further examination
of Trincomalee Harbour and Tamblegam Lake. He gave ten days to the work and
got satisfactory results which I have already noted (see p. 41).

Early in November he joined Captain Legue in the inspection of the pearl banks

NARRATIVE.

95

for the purpose of obtaining a sample of oysters to be valued by the pearl experts at
Colombo in view of the proposed fishery. The following paars were inspected : —
South, East and West Cheval, and Periya Paar Kerrai in considerable detail, and from
these samples were lifted (fig. 27) ; while the following were less fully examined : —
Kondatchi Paar, Dutch Modragam Paar, Muttuvaratu Paar, Chilaw Paar, and
the ground off Negombo. Mr. HoKNELL examined large numbers of oysters from the

Fig. 27. Valuation sample of pearl oysters from the Cheval Paar, being brought on board the
" Rangasameeporawee " from the inspection boats — from a photograph by J. Hornell.

various paars as regards their sexual condition, parasites and the occurrence of pearls.
He also investigated the plankton as fully as possible, and found, on Muttuvaratu
Paar, the youngest stages of the larval Cestode which we regard as the chief cause of
pearl-formation free-swimming in the water.

Mr. Hornell also took a considerable number of living oysters round with him
from Muttuvaratu and Chilaw paars to Galle, where he placed them at various chosen
spots in the lagoon for observation and experiment.

The official samples of pearl oysters taken from the Cheval Paars and Periya Paar
Kerrai in November were valued in Negombo by five expert native merchants and
Captain Legge, the Inspector of Pearl Banks, with the following results :—

12,000 oysters from the South-East part of the Cheval Paar, at Rs. 10 25 c. per 1 000
1,000 „ „ East Cheval Paar, at Rs. 1 8 1 7£ c.

2,000 „ „ North-East part of the Cheval Paar, at Rs. 23 12£ c.

2,000 ,, „ Periya Paar Kerrai at Rs. 13 25 c.

9G CEYLON PEARL OYSTER REPORT.

As a result of this valuation it was decided to hold a pearl-fishery in the spring of
1903 ; and it was announced in the Ceylon Government Gazette Extraordinary
No. 5896, of Decemher 22, 1902, that the fishery would take place at Marichchukaddi,
which is ahout 8 miles south of Chilavaturai, on or about 22nd February, 1903.

The paars announced for fishing were :—

South-East Cheval Paar, with 49 million oysters sufficient for 120 boats for 40 days
East Cheval Paar, „ 11 „ „ „ 28 „ 40 „

North-East Cheval Paar, ,, 13 „ „ „ 32 „ 40 „

Periya Paar Kerrai, „ 8 „ „ „ 20 „ 40 „

Making in all 8 1 millions of pearl oysters estimated as fishable.

Mr. Hornell left Galle on January 27th and arrived off Marichchukaddi, the head-
quarters of the fishery, on January 31st, and in this neighbourhood he remained for
the next three months, leaving on April 23rd and arriving back at the Galle
Laboratory on 4th of May.

The fishery did not commence until March 3rd and it ended on April 15th, having
lasted for 38 days and resulted in a revenue of Its. 830,151 93 c. Thirty-nine
millions of oysters are estimated to have been obtained from the eastern Cheval
paars, and an inspection made by Captain Legge at the conclusion resulted in the
estimate that 22 millions of adult oysters were still left on these paars alone. This
demonstrates one of the obvious imperfections of the method of fishing by means of
native divers. When the divers have made enough money, or are wearied of the work,
or find that the scattered condition of the oysters makes it more difficult to fill their
baskets, they can declare that the bank is exhausted and so cause a premature
stoppage of the fishery. Under such circumstances most of the oysters left at the
bottom might still be recovered by dredging.

In addition to the paars fished, a number of the neighbouring smaller paars were
inspected, and Mr. Hornell was able, by means of the European diving suit which
was now available, to make a personal examination of the bottom and acquire a
fuller knowledge of the conditions than had before been possible. He made ahout
40 descents in all — upon the Cheval, North and South Modragam, Periya Paar
Kerrai, Kondatchy, Aripu, Periya, Dutch Modragam, Naddakudda, Vankali, Anaivel-
unden, Karativo, Alentura and Muttuvaratu paars. On the larger paars several
descents were made, eleven upon the Cheval as the one deserving most attention.
One important result of this personal inspection of the bottom was to establish — if
that was necessary — the correctness of the conclusion we had arrived at during our
work on the " Lady Havelock," that the greater part of the bottom on the pearl-
banks is suitable for dredging, and that the oysters could be obtained from the paars
during a fishery much more effectively and speedily by dredging from one or more
small steamers than by diving. On the Muttuvaratu Paar Mr. Hornell reports

NARRATIVE.

'.17

that three dives showed a dredgable bottom, while the fourth dive was on a spot where
the dredge could not be worked as the " rock rose from the bottom in great plateau-
like ledges." A similar condition was found at one spot on the Dutch Modragam
Paar, but otherwise the bottom all over the productive paars is perfectly suitable for
dredging. The Cheval paars and the North and South Modragams present ideal
bottoms for dredging, or even for working a small trawl upon, being level and
consisting mainly of a thin layer of sand covering a firmer substratum of the cemented
material known as " rock." I shall return to this matter of dredging for the pearl
oysters, in place of diving, in my Recommendations at the end of the Report.

During this period Mr. Hornell also examined large numbers of pearl oysters of
various ages and from different paars and so was able to confirm and extend our
previous observations. He was esj:>ecially successful in obtaining stages in the
formation of pearls, and in the life-history of the pearl-causing parasites. The details
obtained during this three months' work on the pearl-banks have been incorporated
with our other investigations (l) on the condition of the ground (see p. 99); and
(2) on the parasites and pearl-formation, in the parts that follow.

For some weeks after this Mr. Hornell was engaged at Galle in completing his
notes and records of observations and in packing off to me the specimens which had
to be examined in Liverpool, and so finished his work as my Assistant in this
investigation. If he is enabled to continue his observations as a Marine Biologist at
the Galle Laboratory, judging from the industry, energy and ability he displayed
during the time we were associated in work, I can confidently predict that he will
render signal service to the pearl, sponge, trepang and other marine fisheries of the
colony.

The inspection barque " Rangasameepor

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Fig. 28. Chart of the Northern Paars.

[ 99

DESCRIPTION OF THE PEARL-OYSTER BANKS
OF THE GULF OF MANAAR.

The following account of the physical and biological characteristics of the various
"paars" on the Ceylon side of the Gulf of Manaar is drawn up partly from the
information obtained by dredging over the ground from the ss. "Lady Havelock,"
partly from our lines of dives from the " Serendib " during the inspection of March,
1902, and partly from the additional information which Mr. Hornell obtained during
the fishery of 1903. On this last occasion a European diving dress was available for
use — which we had not had in 1902 — and consequently Mr. Hornell was enabled to
descend himself, and so corroborate, correct, and supplement the information derived
from the natives* by many further details. The lists of animals found on the
" paars " given here are not intended to be exhaustive, or even full. The object is
merely to mention a few of the more characteristic organisms in each case.

The paars may be arranged in two groups, the Northern from Adam's Bridge down
to Kodramallai, and the Southern from that point onwards ; we give a chart (tig. 28
and fig. 37) of each group. The Northern is by far the more important; it contains
more paars, they are of larger extent, and have produced most of the recorded
fisheries. The pearl-bank plateau, bounded for the most part by the 10 or 12-fathom
line, widens greatly in the northern part of the Gulf of Manaar as it approaches
Adam's Bridge (see fig. 1, p. 19); for whereas off Negombo and Chilaw it is only
3 to 6 miles from shore, off Aripu and Kondatchi it is from 16 to 20 miles.

This widening of the plateau north of Kodramallai allows the northern paars to
form several series, one outside another, and roughly parallel with the coast, the inner
series being about 4 and the outer 18 miles from land. Outside the paars the
ground shelves away rapidly to 20 or 30 fathoms, which marks the top of the steep
slope down to the mud-floored abyss forming the central portion of the Gulf. Along
the line of this slope soundings in some places jump in very short distances from
20 fathoms to anything between 100 and 1000, with, of course, interesting differences
in the fauna. Within the 10 or 12-fathom line, on the other hand, the ground is for
the most part very level, especially on the wider northern part of the plateau. At
the Cheval Paar a distance of 12 miles is run from shore before a depth of 7 fathoms
is reached — a gradient of 1 in 1700. The surface of this plateau is for the most part

* Mr. Hornei.l, writing to me of the results of his inspection, says that he finds the diagrams compiled
from the divers' reports erroneous, and adds, " On the other hand, the results obtained by dredging —
which sometimes clashed with the divers' reports — were proved to be reliable, and indeed wholly
accurate. The conclusions based upon this source of information require no emendation — merely
amplification."

O 2

100 CEYLON PEARL OYSTER REPORT.

sand, diversified here and there by cmtcrops of so-called " rock," generally in the form
of flat or slightly-inclined ledges, sometimes stepped to form low terraces, sometimes
level with the surface, and sometimes even a few inches under it, the rock being then
covered by a thin layer of sand, which shifts from time to time with the currents.

Some of the paars, such as the Muttuvaratu, Karativo, Dutch Modragam, and
parts of the Western Cheval, are formed almost entirely of rock, and the small amount
of sand found in crevices and sprinkled over parts is mostly of organic origin —
He'erostegina, Alveolina, Orbitolites, and other large Foraminifera and fragments of
shells. On other paars, such as the East and South Cheval, angular quartz sand
predominates, sometimes underlaid by flat rock which crops out at intervals. Mr. J.
Lomas, F.G.S., who has examined the samples of " rock " we obtained from the
paars, is of opinion that they are all of recent origin, and are in fact merely a
consolidation or cementing of the sand in situ. Further details of the nature of these
modern calcareous rocks or " Calcretes," and of their mode of formation on the paars,
will be given in Mr. Lomas' report which follows.

The calcretes naturally vary considerably from place to place, being in some cases
mainly composed of terrigenous materials and in others being mainly neritic or
formed of organic remains. The rock may be a grit stone formed of the yellow-tinted
quartz sand, which is so abundant, cemented by carbonate of lime, or it may be largely
dead worn and altered coral, or it may be a shelly mass, an agglomerate of the dead
valves of pearl-oysters, cockles, and Pectunculids with Nullipores (Lithotha/mnion)
and Polyzoa (Lepralids) intermingled.

In addition to the paars described below, there are a few others, marked on the
chart as " Old " or "Old Dutch" (see figs. 28 and ?>7), which are either erroneous
positions of other paars now more accurately determined or are patches which formerly
bore oysters and have since changed their character.

We must not, however, try to be too precise in regard to the positions, sizes, and
outlines of the paars. Our work in the "Lady Havelock " showed us that some
spots around and between them are more or less hard-bottomed, and even in some
cases bore oysters and are capable of becoming paars. On the other hand, it is
known from the inspections that many parts of the known jsaars are temporarily, and
possibly some parts even permanently, unsuitable for the attachment or rearing of
oysters. We may consider, then, the whole plateau as potentially " paar " ground —
some parts of it better suited for one purpose and some for another, some parts more
constantly covered by the shifting sands, others more regularly bare and hard. This
renders possible the farming operations, such as " culching " and transplanting, which
we discuss in our " Recommendations."

Cheval Paar.

This is the most important and the largest of the paars, and is the central member
of the northern set, most of the other paars being grouped around it (see fig. 28).

DESCRIPTION OF THE FEARE-OYSTER BANKS OF THE GULF OF MAXAAl;. 101

It lies from 9 to L3 miles off the coast, opposite the bight of Kondatchi, the northern
point being due west of Aripu and tbe southern of Kallar tower. The paar extends
for about Gi miles from north to south, and A\ miles from east to west, but is not all
occupied by pearl oysters. The depths vary from 5 to 8^ fathoms. The paar is
usually divided into an eastern, a western, and a connecting southern portion, and in
most of the fishery charts since the time of Steuaft (1843), these have been combined
to form a conventional horse-shoe shape, which, however, does not now correspond at
all accurately with the area covered, or likely to be covered, by pearl oysters.

The parts of the paar differ considerably in character, the east and south being
more or less sandy, and the west, and especially north-west, more rocky ; and the
effect of this difference can be traced in the condition and history of the pearl oysters
from these parts.

The Cheval Paar has yielded many important fisheries. During the nineteenth
century we find that the whole or parts of it were fished in 1804, 180(5, 1808, 1809,
1814 (the largest fishery recorded), 1816, 1820, 1829, 1830, 1831, 183G, 1837, 1855,
1857, 1858, 1859, 1863, 1874, 1877, 1880, 1881, 1887, and 1888. In the earliest
records the Cheval and Modragam paars are united as the Aripu banks.

West Cheval. — Here the bottom, especially towards the north, is very rocky, with
little sand. The depth is mostly about 7 to 8 fathoms. The rock is a compact shelly
limestone with some quartz sand cemented to it by carbonate of lime. It is much
overgrown by Algae and Sponges, and the Sargassum weed is especially abundant.
Bare parts of the rock are of a reddish-yellow colour from ferruginous staining, and it
is all much tunnelled by Clione and boring Molluscs. Between the long level stretches
of rock are smaller sandy tracts, especially towards the south, where the sand is
irregular, rising up into little hillocks, amongst which are scattered Nullipore balls and
hemispherical Astraeid corals. This large extent of rock, some hundreds of acres of
continuous hard bottom, offers favourable conditions for the attachment of spat, and
the area is notably prolific. During our inspection in March, 1902, Captain Donnax
estimated that there were, on the West Cheval, 123 millions of oysters as against
74 millions on the eastern side of the paar. This abundance carries with it, however,
the attendant danger of overcrowding as the oysters grow older, and appears to result
in a stunted condition and, it may be, disease and wide-spread mortality. The dwarfed
state of the oysters on both the North-west Cheval and the Muttuvaratu Paar has
been recognised by the divers, and by the Inspectors in their reports, as the
" Koddaipakku " variety (see, for example, Sir W. Twynam's " Keport "). Captain
Donnan remarks, under date 18th March, 1901, '"I have noticed on previous
occasions that young oysters on the East Cheval grow much larger and quicker
than oysters on the West side of the Cheval." We found the average size of a
fair sample of oysters from the North-west Cheval to lie (March 27th, 1903) :
61 -50 X 58'33 X 2684 millims., while the average size from North-east < 'heval
was 76*05 X 71 '45 X 3T45 millims., and the average from Muttuvaratu was

L02 CEYLON PEARL OYSTER REPORT,

57 '54 x 54 "00 X 24 -42 millims., all being of the same season, from 3J to 3f years old.
The stunting, although less marked than in the case of the Muttuvaratu Paar, is
apparently a permanent characteristic of the North-west Cheval, and is flue, we
consider, to the conditions which favour an abundant deposit of spat leading afterwards
to overcrowding and insufficient food.

The characteristic organisms on the bottom are : —

Saiyassiini and other Algae (Padina and small Floridese) in profusion ;

Spongionella nigra, and a few Corals such as Turbinaria cinerascens and some
Astrasids ; the large red starfish Pentaceros lincki, a fine species of Cidaris and
Antedon. Quantities of Aplysia were seen, also LameJlaria, Chromodoris, Scyllcea
and Eolids ; Pinna lay flat on the rock in place of being partially buried in sand.
The large pinkish Ascidian Rhabdocynthia rosea was also present.

East Cheval. — The bottom here consists of fragments of rock embedded in or covered
with a few inches of sand. One piece brought up by the divers from the North-East
Cheval (6^ fathoms) was a tabular calcareous mass, 4 feet by 2 feet by 4 or 5 inches
thick, upon which about a dozen pearl oysters were attached, distributed as
follows : — One end of the block projected above the sand and bore most of the
oysters and some small Alga?, &c. ; the other end was covered with a thin layer of
sand, but had 5 oysters attached, the byssus passing through the sand to join the
rock below — several other byssus tufts were also present ; finally the middle, lowest,
part was more deeply buried in sand and showed no trace of oysters. This case was
typical of many '" rocks" examined. The block was composed mainly of dead coral,
upon which old worn shells and quartz grains had become cemented; partly by
deposition of carbonate of lime and partly by incrusting calcareous Algae, Polyzoa.
and Serpulid tubes. The deeper parts showed ferruginous staining, and the cavernous
condition of the interior in this and other blocks was due partly to the irregular
disposition of the original components now cemented, and partly to boring by Clione
and Molluscs. While at the north end of the paar the rock seems to be mainly dead
coral, a little further south it becomes a grey-green compact grit stone cemented by
carbonate of lime and incrusted with Nullipores and Polyzoa.

Over much of the East Cheval sand predominates on the surface, underlaid by
rock, at a depth of 6 inches to 2 feet, from which in places corals and other colonies
project above the sand. The pearl oysters, in our experience, were fairly evenly
distributed, and in quality they proved to be the best of all those examined or fished.
They were well-grown and vigorous (fig. 29), and richer in good pearls than any
others.

In the sandy parts the pearl oysters are attached through the sand to buried
fragments of rock, coral, or any firm substance. Sometimes one oyster is attached to
a piece the size of a walnut, and two or three others are fixed to the shell of the first.

On this part of the paar large Algae are scarce, but there were plenty of small
Floridese, Padina, Laurencia (boiled into jelly and eaten by the natives), Poly-

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 103

sipkonia, Corallina; and a Cauleipa straggles through the sand. Amongst the
commoner animals were hemispherical Astrseid Corals, a small Fitngia (F. dent"!",

Fig. 29. Pearl-oysters from East Chev.il Paar showing growing edges.

young, see fig. 30), a few Holothurians (//. atra), and the red Pentaceros and very
many young Aplysia. But the most characteristic animal of this part of the Cheval
Paar is the large Hydroid Zoophyte Campanularia ju?icea, which comes up in great
hunches not unlike cut " heather," the name by which it has been sometimes indicated
in the Inspectors' reports. The sand is largely composed of shell fragments, Nullipores

Fig. 30. Fungia dentata, living and expanded specimens from the East Cheval Paar, natural size. —

From a photograph by J. HoRNEt.i,.

and Foraminifera. Other animals found here were Spongionella nigra, fjiiu-ki". sp..
orange Gorgonids, and species of Haliotis, Area, Cardium, and Turbinella.

At the south-east corner of the Cheval we found that out of 307 dives I I brought
up adult oysters (7 from rock and 4 from sand), 2 IG brought up young oysters, (it
were on bare sand and 16 on rock without oysters.

About the middle of the East Cheval there are rocky patches of (puutzose
gritstone, which are too rugged to he fished by dredging, and yet are crowded with
oysters. The few such areas on the pearl-banks might be cleared by divers, or if left
unfished would no doubt form valuable breeding reserves.

104

CEYLON PEARL OYSTER REPORT.

South Cheval. — Unlike the eastern and western regions to the north, a remarkable
uniformity characterises the whole of the southern part. The bottom is very level
and is composed of sand and shell gravel, the latter chiefly the broken and worn
fragments of pearl-oysters, Pectunculids, and Cockles. Scattered about in great
profusion lie also fragments of dead coral, calcareous rock, shell-conglomerate, balls uf
Lithothamnion (fig. 31), from the size of a hazel nut to that of a cricket ball, and dead

J ,vv ■-- ■^•rfflft" ^^^^ <^^m^

*

3?M

s^ffcj

PwSr

Fig. 31. Nullipore ball (Lithotluimnion fruticulosum) with tags of byssus where pearl-oysters have
been attached (to the right), and similar ball still covered with young pearl-oysters (to the left);
natural size.

shells. These fragments rarely exceed G inches in diameter, but some larger blocks ot
rock lie buried under the sand. Very rarely, however, is there any sign of extensive
rock, such as is seen in the more northern parts of the paar, and none rises above the
surface. This, like so much of the ground on the pearl-banks, is excellently suited
for dredging over.

The pearl oysters lie for the most part loose on the sand in bunches, each bunch
having in its centre one of the fragments of coral, rock, or nullipore. Often one
oyster has three or four small stones and shell fragments entangled together m its
byssus, while other individuals, usually younger, cling to its valves. There may be
any number from 3 or 4 up to 15 or 16 oysters in a bunch. Some of the bunches
(fig. 32) are formed of young and old individuals, ranging from I month up to nearly
4 years of age, joined together.

Non-calcareous Algas are scarce here, Pentaceivs and Holothurians are fairly
common, and the Hydroid Zoophyte Campamdaria junaea is characteristic of the
eastern end and extends north along the East Cheval. SpongioneUa nigra, Famjiu
dentata, and Astrseid Corals are also common, and a large mass of the delicate
Annelid tubes, Filograna, was obtained near the shoal buoy. Dead oyster shells are
very abundant at the eastern end, and it is here that we find the occasional lumps of
shell-conglomerate formed of pearl oyster valves up to 4 years old, shells and casts of

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 105

Pectunculids, Cardium, Macro,, Venus, &c, cemented together by mere films of
carbonate of lime, supplemented in places by patches of Litkothamnion and Lepralid
Polyzoa. This shell-conglomerate may be ferruginous like the Red Crag Deposits.

Fig. 32. Four generations of pearl-oysters from the Cheval Paar. The largest is 3f years old, the
next is 18 months, two (above) are 8 months, and one (on the large shell) is about a month old.
— From a photograph, March, 1903.

The cup-shaped horny sponge Phyllospongia holdsworthi is abundant at the
western end, and, though not confined to this region, as has been supposed, is so
characteristic that the native divers have named the western
part of the bank the Koddai (or " Umbrella ") Paar.

A comparison of these different parts of the Cheval
Paar shows the great importance of scattered " culch " such
as dead coral fragments, Nullipores, and old shells as a
basis of attachment for the pearl oysters. The large embay -
ment (fig. 32a) between the East and West Cheval has a
bottom of sand, much of which could be made available
for oyster cultivation by a system of "culching" with
material brought from the beach or from any of the coral
patches (Aripu, Kodramallai, &c.) in the neighbourhood.
The limits of the paar might also, by the same process, be
extended at least half-a-mile further to the east.

g. 32a. Proposed cul-
ture areas recommended
for the Cheval Paar and
Peiiya Paar Kerrai.

Modragam Paar, North.

This paar lies south-east of the central part of the Cheval Paar, at from \ mile
to 1 mile distant, and is nearly 1 mile in diameter. It is about %\ miles west of Kallar
tower. The depth is from b\ to 6f fathoms.

The bottom is sandy, ridged and furrowed ; no rock is to be found.

The pearl-oysters are in bunches lying on the sand, chiefly in furrows, each bunch
having in its centre some fragment of dead coral, nulhpore, calcrete, or other hard
substance, to which most of the oysters are attached. In the first four bunches

106 CEYLON PEARL OYSTER REPORT.

examined the numbers were 10, 8, 21 and 11 respectively. A characteristic feature
is the number of barnacles and small rock oysters incrusting the valves.

Caulerpa (? C. scalpelliformis) is common here, growing in the sand along with the
Phanerogam, Halophila ovata, of similar habit.

Amongst the animals noticed were : — Clypeaster humilis, Salmacis bicolor, Luidea
maculata and Pentaceros hncki.

Captain Donnan reported that the pearl oysters on this paar were " in great
abundance in large clusters" in 1856 and again in 1857. These were fished in 1859
and in 1860. The paar yielded a small fishery in 1877 and a larger one in 1887, and
again in 1888, when both Modragams were fished along with the whole of the Cheval
Paar. The oysters on this paar are well grown, but seem limited in number for want
of a hard bottom for attachment. The benefit of " culching " such a locality as this
must be obvious.

Modragam Paar, South.

This lies 1 mile south-south-east of the North Modragam, and is about |- to f mile
in diameter. It is about 7 miles north-north-west of Kodramallai Point, and has a
depth of 5^ to 6 fathoms. The bottom is rocky but very level, and appears to be
covered in its entire extent with a thin layer of sand, in which there are many broken
shell fragments, especially pearl oysters, Cardii.ua and Pectunculus. There are some
Alga?, but when we examined the paar, very few pearl oysters.

Amongst the characteristic animals are : — the sponges Axinella donnanl and
Spongionella nigra, and many Astrseid corals — small hemispherical colonies projecting
through the sand and apparently attached to underlying rock.

This paar, along with the North Modragam, has usually been fished at the same
time as the Cheval, but it apparently yielded important fisheries alone in 1828 and
in 1860.

Kondatchi Paar.

This lies closer in-shore than the Cheval Paar, and about 1 mile due east of its
southern end. It is about 1 mile in diameter, 7 miles off-shore, and has depths ot
4 to 5 fathoms.

The greater part of the area is sand. Out of 171 dives 14 only were on rock,
157 on sand. There are occasional little patches of partly buried rock jjrojecting from
the smooth sandy surface. This paar is recorded to have only once yielded a fishery —
that of 1801. There are now only a few pearl oysters, of mixed sizes, along
with Pinna bicolor, Luidea maculata, and several kinds of Pentaceros — one very
common species (?) is nearly black in colour, with red tops to the rounded tubercles,
another form is grey, and another shows orange blotches and tubercles. Pennatulids,
spinous and purple coloured, which had obviously been embedded in the sand, were
also brought up. The shells of the pearl oysters were incrusted with small rock
oysters (Ostrcea sp.).

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 107

When we saw this hank in March, 1902, it had a crop of pearl oysters estimated
at 5| millions. These had nearly all gone by March, 1903, and it is probable that
their disappearance may be accounted for by the very large numbers of starfishes
present, especially Pentaceros lincki (fig. 33).

Fig. 33. Pentaceros lincki, de Bl., lying on a large pearl-oyster, half natural size. — From a

photograph by J. Horneli..

Jagerboom Paar.

This lies 2 miles south of Kondatchi Paar and about 6j miles off-shore, opposite
Kallar. It is about 1^ miles across and has depths of 4 to 5j fathoms. The divers
brought up pieces of the " rock " bottom, which consisted of rough quartz sand
cemented by carbonate of lime, together with fragments of shell.

There are many starfishes (Pentaceros lincki) on this paar, as on Kondatchi Paar,
and these probably contribute to the mortality of oysters.

An old Dutch " Jagerboom " bank is also marked on the charts about 2 miles
south of the West Cheval and outside the Modragams — it is now covered with sand.

Kallatidel Paar.

This little paar lies 1^ miles to the east of the Cheval Paar and is about 7 miles

off Aripu. It is nearly 1 mile in diameter and the depth is 5^ fathoms. It is, in its

present condition, unimportant.

Aripu Paar.

This lies 6 miles due west of Aripu, and 4 miles north-east of the north of the
Cheval Paar. It is 1 mile in diameter, and the depth is 4 to 5 fathoms. Some old
Dutch paars, marked on the charts as " Aripu," lie close to and outside. They are
now covered with sand and are unimportant. About 1 mile further inshore lies Aripu

P 2

108

CEYLON PEARL OYSTER REPORT.

Coral Reef, round which is a hard patch of nearly 1 mile across, with depths of 2-^ to
4^ fathoms. This, although itself unsuitable for oysters, is of value in supplying dead
coral fragments, &c, as " culch " to neighbouring grounds. The bottom is level,
consisting of sand and shingle lying on a foundation of flat rock. The sand varies
from a mere sprinkling to a good depth. There are also some Nullipore balls, coral
and shell fragments, and masses of cemented sand. Living corals are more abundant
than on any part of East Cheval, no doubt owing to the proximity of the reef.
Amongst the more abundant organisms were : —

CD O

Various Algae (including a Galaxaura, a fleshy Laurencia and Halimeda tuna),
Spongionclla nigra, Axinella donnani, Phyllospongia holdsivorthi, Turbinaria
cinerascens and T. crater, Sarcophytum sp., Pentaceros sp., Linckia sp., and other
starfishes, Holothuria atra and other species, Ophiuroids and Palinurus sp.

The records of important fisheries early in the Nineteenth Century (between 1804
and 1820) on Aripu Paar do not refer to this little patch alone but to the great banks
lying "off Aripu," viz., the Cheval and Modragam paars.

When we examined this paar there were comparatively few pearl oysters, but they
were of various ages.

Challai Paar.

This little paar lies 5 miles to the east of the Cheval Paar, and about 4 miles
south-west of Aripu. It is the nearest paar to land in this region, is about 1 mile in
diameter, and 2\ to 4^ fathoms in depth. It does not now support any oysters, and
is unimportant.

Periya Paar Kerrai.

This lies about 1 mile north-west of the most northerly point of the East Cheval
Paar, and is about 12 miles west of Aripu. It varies from \ mile to l\ miles across,

Fig. 34. Plan of the Periya, Paar Kerrai. The whole line surrounding A shows the area as inspected in
1882, the dashed line round B shows the paar in 1884, the dotted line round C shows the condition in
1886, while the two black patches indicate the parts fished in 1835 and 1836.

and has depths of from 7 to 9 fathoms. The diagram (fig. 34) shows how the hard
area forming the paar has varied in extent and shape from time to time.

The bottom is flat, being a continuous stretch of " rock" overlaid by a thin layer ol

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 109

sand. The samples we obtained were calcretes, largely encrusted with Polyzoa and
Nullipores, and some shell conglomerates (fig. 35) formed of casts of the valves of
pearl oysters, Cardium, Pectunculus, Murex,
and Cerithium. Here and there the sur-
face of the rock is exposed and coated by
Nullipores and other encrusting organisms,
and there pearl oysters (fig. 36, o.), or the
marks of their byssus (b.), are found in
quantity. Many crushed valves and broken
fragments were also seen, showing that
many more pearl oysters had been present
lately. We attribute the destruction in
this case to the carnivorous fish Trygon
uarnak browsing over the bottom.

Very little coral is present here — a few Astrseids only were found. There is some
Sargassum and a few other Algse (Acetabularia, Laurencia, and Lithothamnion balls),

Fig. 35.

Shell conglomerate from Periya
Paar Kerrai.

• ***i

-U.j)1

Fig. 36. Diagram illustrating the distribution of pearl-oysters and old byssus on " rock " and sand.

some black sponge (Spongiondla nigra), a few trepang (Holothuria atra), and some
starfishes (Pentaceros linchi). This paar yielded important fisheries in 1833, 1835,
1836, and then was not fished until 1903.

Outer or True Vankali Paar.

This lies 2 miles north-west of Periya Paar Kerrai, and about 14 miles due west
of Aripu. It is 1|- miles in diameter and the depth is 6^ to 8h fathoms.

The bottom is flat " rock" covered with very many dead shells of pearl oysters, and
other Mollusca, with comparatively little sand.

Amongst the other animals noticed were : —

Spongionella nigra, Astrseids (small colonies), Juncdla juncea, Antedon — black and
grey on the Gorgonids, Psoitis sp., Balanus sp. (large), Galathea comatulorum (this
and a similarly coloured Myzostomum were attached to the Antedon), Turbinella rapa,
Murex regius and some fishes (Labridse and species of Balistes).

110 CEYLON PEARL OYSTER REPORT.

Inner Vankali Paar.

This lies f> miles further east and is about 7 miles west of Aripu. It is about
\h miles in diameter, and the depth varies from 3 to 6 fathoms. This is a patch of
rocky bottom, but close outside it are several old paars, named Vankali on the charts,
which are now covered with sand.

Young oysters have been found on various occasions on the Vankali paars, but there
has never been a fishery. In April, 18G2, Mr. Vane reported a large bed of young
oysters in this region, covering an extent of 3 miles, but they did not remain.

Anaivelundan Paar.

This is the most northerly paar, and lies 4^ to 5 miles south of Adam's Bridge and
nearly 8 miles south-south-west of Talamanaar. It is about lj miles in diameter and
has depths of 4 to 6 fathoms.

The bottom is composed of level "rock" overlaid with a thin sprinkling of sand.
Attached to the rock is found much broad-jointed Halimeda (H. tuna var. platydisca),
and also other Algae, including Chrysymenia uvaria, Udotea fabellata, Dictyurus
purpurascens, Kallymenia perforata and species of Laurencia, Polysiphonia,
CoraUina, Acetabularia, and quantities of Sargassum.

The most characteristic animals of this paar are the corals Turbinaria cinerascens
and T. crater, the so-called elephant's-ear corals, from which the paar takes its native
name.

Naddakadda Paar.

This lies 2% miles east of Anaivelundan Paar and 7 miles south of Talamanaar in
Adam's Bridge. It is LJ miles in diameter, and the depth is 4^ to 5^ fathoms.

The bottom is formed of ridged sand, the underlying rock only showing in a few
places. There are some Algae (Kallymenia perforata, &c.) on the bottom, and some
Axinella donnani, but no coral was found, and no pearl oysters.

The pearl oysters which have sometimes been found on this paar, and are sometimes
washed up on the south of Manaar Island, are said to be of a flat shape and to have
very few pearls.

To the south of this, and near the north end of the Periya Paar, two old Dutch
paars are marked on the charts, which may he either erroneous positions of the
Anaivelundan and Naddakadda or may be former paars now covered with sand.

Periya Paar.

This is a very long bank running north-north-west and south-south-east about
16 to 18 miles from land. It is about 11 miles in length and averages 1|- miles in
width. It is the paar that lies furthest from the shore, and has only been fished once,
and then only the south-eastern part, in 1879. The depth varies over the different

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. Ill

parts of the area from 1\ to 13 fathoms, hut the greater part of it is ahout 9|- to 10
fathoms.

The bottom is a few inches ol coarse quartz sand covering flat rock. The sand has
ridges ahout 2 feet apart, and has plenty of small " culch," chiefly shells, lying in the
hollows. In other parts the rock is exposed and covered with abundance of Padina
and other Algae, also Nullipore balls (Lithothamuion fruticulosum). The rock is, in
the northern part, a fine grained calcareous sandstone much incrusted with Polyzoa,
while further south it is a looser, more porous calcrete of a whiter colour.

Amonost the common animals found were : —

Axinetta donnani, Spongionella nigra, Petrosia testudinaria, pink and white
mottled Pennatulids, Heteropsammia, Astrseids and Turhinaria, Eunicid worms,
Linckia sp., Cassis, Pectunculus, Area, Chama, Venus and other shells, Labrus,
Batistes, Gobies and other fishes.

Even where the rock is exposed on this paar it would be suitable for dredging over
— a matter of great importance, as this is the ground from which the largest supplies
of young oysters can be obtained for transplanting to more reliable paars. Some
further particulars in regard to this paar will be found in the " Narrative" (p. 76).

The Southern Paars form for the most part a single series running north and
south parallel with the coast from Negombo to Kodramallai. Off Chilaw, however,
they become more extensive and allow of division into an outer paar and several
inside it. At the northern end, also, off Karativo Island, the plateau widens, and is
occupied by the large and important Muttuvaratu and several smaller paars. The
chart of the Southern group (fig. 37) shows the paars from Kodramallai Point down to
Navakaddua. The few banks remaining to the south of this (Jokkenpiddi, Oolawitti,
and those off Chilaw and Negombo) are too distant to be included in the same figure,
and scarcely require separate illustration. Their general position can be seen from
fig. 1 and fig. 22, in the " Narrative."

These more southerly paars resemble closely in character the Periya Paar on the
outside of the northern group. They are stretches of sea-bottom wherethe under-
lying calcrete or modern rock comes to the surface at intervals, or where loose
fragments — lumps of calcrete, Nullipore balls, and dead shells — lie upon the surface,
forming natural " culch " to which oyster spat can become attached. The exact con-
ditions vary at different points along the coast, and, as might be expected, there are
local differences noticeable in the fauna of the paars, which is affected by such factors
as differences in depth, degree of exposure, and proximity to inlets of fresh water.

Dutch Mo drag am Paar.

This lies 10 miles due west of Kodramallai Point and about 10 miles south-west
of the North and South Modragams, and due north from Karativo Paar. It is
1^ miles in diameter, and varies in depth from 8 to 14 fathoms.

„;■' &£?"'. ;s

Fig. 37 Chart showing most of the Southern Paars.

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 113

The bottom is rocky — a very coarse quartz grit cemented by lime, and with dead
coral imbedded in places (Madrepora, Monlipora, &c). Foraminiferal sand (Hetero-
stegina, Orhitolites, &c.) is present between the harder parts.

Out of 260 dives, 144 brought up adult pearl oysters, in 7 cases on sand and in
137 on " rock." The remaining dives were 83 on sand and 33 on rock not occupied
by oysters. The pearl oysters are not very abundant and look rather stunted, and
are overgrown with Leptoclinids, Sponges, small Algae, and Serpulids ; they are very
similar to those on the Muttuvaratu Paar. Living Fungia, Manicina, and a few
other corals are found, also Culcita schmideliana, Linckia laevigata, Margaritifera
margaritifera (the " black-lip " pearl shell), many fishes, such as Batistes rnitis,
B. stellatus, and some Gobies.

This is one of the few paars on which it would be difficult to fish the pearl oyster
by means of dredging. The bottom is so uneven and so rough with corals that the
nets would be torn to pieces and the frames be broken, unless great care and skill
were employed.

This paar is placed a couple of miles further to the north-east in an old Dutch
chart. That may either be an erroneous position or may indicate a former patch of
hard bottom.

Kaeativo Paar.

This lies 5 miles due west of the northern end of Karativo Island and 1 mile south
of the Dutch Modragam. It is about 1 mile in diameter, and has depths of 8 to 10
fathoms. The bottom is very rocky and uneven, and it is one of the few spots that
would be impossible for dredging. The rock is in the form of ledges, steps, or
escarpments, with sometimes fully two feet of rise.

Scarcely any pearl oysters were seen, but amongt the few there was a living
" black-lip " pearl oyster [Margaritifera margaritifera, Linn.). We also noted: —
Madrepores, abundant, Tridacna sp., Psolus sp., Asterias sp., and shoals of Plecto-
gnathid fishes.

This paar was fished in 1832, and then again in 1890 and 1891, one day in each
during the fishing of the Muttuvaratu Paar.

Alantura Paar (Hamilton's).

The paar lies about 1 mile to the south of Karativo Paar and 4j to 5 miles off
Karativo Island. It is nearly 1 mile in average diameter, and the depth is 8 to 11
fathoms.

The bottom is very even — strewn with quantities of Nullipore fragments and other
pieces of " culch," under which is Heterostegina and Orhitolites sand covering the flat

114

CEYLON PEARL OYSTER REPORT.

" rock." There are few attached coral colonies, but very many of a thin brown species
of Flabellum lying on the sand.

This paar presents an excellent bottom both for the deposit of spat and also for
dredging.

MlJTTUVARATU PaAR (DoNNAN's).

This lies 5 miles west of Karativo Island and 3 to 4 miles south of Hamilton's
Alantura Paar. It is 2j miles long (north to south) and 1^ miles wide (east to west).
The depth is 5 to 10, mostly 7 to 8 fathoms. On the whole it has a level hard
bottom, and any little sand present is Foraminiferal. Of 289 dives, all were upon
" rock," and 238 yielded adult oysters. Only the dives to the west part, in deeper
water (fig. 39, A), were unproductive. This paar was covered, when we examined it,
with plenty of pearl oysters, which are small for their presumed age, but thick, and
with little or no signs of rapid or recent growth on the margins.

Oysters on this paar are rather characteristically associated with corals of the
genera Madrepora, Porites, Pocillop07-a, Montipora, Favia and Goniastrea, growing
upon the left valves which always lie uppermost in the usual position of the oyster
(fig. 38). Some specimens are much overgrown with Polyzoa, sponges, &c. The

Fig. 38. Old pearl-oysters from the Muttuvaratu Paar, with large Madrepore Corals growing on the

shell — half natural size.

oysters are also notably stunted in appearance, and their small size, compared with
oysters of the same age from Cheval Paar, is well known, and has been recognised by
various writers.

We found the specific gravity of the sea to be unusually low in this neighbourhood
(r0208, at a temperature of 85° F.). This may be due to proximity to the mouth
of Putlam Lake, which probably discharges a considerable amount of fresh water
derived from the Kala Oya and the Mi Oya "Rivers. The bottom on this paar is flat
" rock " with many small colonies of Astrcea, Cceloria, and allied low-growing
corals, with occasional bushes of large branched Madrepores, such as M. cervicomis
and M. cytherea, rising to 18 inches or 2 feet in height. The pearl oysters on this

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 1 1 5

paar in March, 1903, were "incredibly numerous, thousands in sight, crowding and
even hiding the rock to which they anchor. One had to trample on them as one
walked — no vacant spots to put the feet." Mr. Hornell estimated them at about
125 adult oysters to the square yard. Captain Donnan's estimate in March, 1902,
was 277 millions for the whole paar. This number has probably been greatly reduced
since by disease. Fig. 39 gives some idea of the number and distribution of oysters
in November, 1902.

Batistes stellatus, the file fish, seemed, during the inspection, to be very abundant
on this paar, much more so than in the Cheval district. Many were seen in the water,
and the boat's crew caught six in a quarter of an hour. It is interesting to note, in

Fig. 39. Inspection charts of (A) northern and (B) southern parts of Muttuvaratu Paar in November,
1902. There are four concentric circles made by the divers' boats between the centre and the
{-mile buoy, four between that and the J-mile buoy, and four from that to the f-mile. Each
complete area is therefore 1-| mile in diameter. The numbers enclosed in rings indicate depths
in fathoms. The numbers on the concentric circles give the quantities of oysters brought up at
a dive on that spot. The cones indicate dives on a rocky bottom with no oysters. The dotted
line therefore surrounds the oyster-bearing area.

connection with this abundance of Batistes, that the oysters examined here are infested
with Tetrarhynchus cysts to a much greater degree than those from any other bank.

This paar is essentially a rocky bank, well adapted for the deposit of spat, but less
suitable than the Cheval Paar for rearing adult well-grown healthy oysters. It is the
same type of paar as the Dutch Modragam and the Karativo. Amongst the other
animals seen were the sponge Phyllosjwngia holdsworthi, the starfishes Pentaceros
lincki, Narcloa tuberculata, Ophiocoma scolopencbrina and Linckia Icevigata, various

Q 2

116 CEYLON PEARL OYSTER REPORT.

living corals ( Turbinaria, Montipora), Sarcophytum, Socarnes sehmardcs, Tridacna sp.,
and Area sp.

This paar yielded important fisheries in 1889, 1890, and 1891, the last being one oi
the most valuable fisheries that has ever been held, over 44 million oysters being
fished at a return to Government of over 963,000 rupees. The bank had never been
recorded as fished before 1889, and it is said that it was unknown to the Dutch in
1757, although we believe we have evidence that it was the source of fisheries in
earlier Portuguese times. Captain Donnan says that a bed of oysters died on this
paar unfished in 1860 ; another bed disappeared in 1899.

To the north and east of the paar proper, in 7 to 8 fathoms, we found a hard and
in some places rough bottom with plenty of " rock " and other hard fragments
which would serve as " culch " for oysters. In places there are large branching
Madrepores and great vase-like elephants-ear corals (Turbinaria) ; also Phyllo-
spongia holdsworthi and other sponges. While the greater part of the ground, like
the Cheval, the Modragams and the Periya Paar could be readily worked with
the dredge, there are certain parts of this paar and the neighbouring ground which
are unsuitable for dredging, and would, if that method of obtaining the pearl oysters
were adopted to the exclusion of diving, form valuable preserves where the necessary
stock of breeding oysters might remain undisturbed.

There is a diseased condition that the Muttuvaratu pearl oysters seem liable to, in
which the body is stunted and shrunken, and the mantle and other tissues become of
a markedly opaque yellow colour. This yellow condition has been noticed in the past
by Sir W. Twynam and by Captain Donnan. We found some affected specimens
during our first cruise in the "Lady Havelock" in February, 1902, and others on
every occasion when the bank has been visited since. On 14th April, 1903, out of
227 oysters examined, 25 were affected with the yellow disease, over 11 per cent.
This condition, which seems to cause considerable mortality amongst adult oysters,
will be discussed in the account of our laboratory work later on in the Report.

Hamilton's Muttuvaratu Paar.

This bank lies 2 miles south-east of Hamilton's Alantura Paar and 2^ miles oft
Karativo Island. It is 1 mile in diameter, and the depth is from 4^ to 6^ fathoms.
The bottom is irregular, partly rock and partly sand.

There were no oysters, and this paar is unimportant.

MUDALAIKULI PAAR.

This lies 3 to 4 miles south of Muttuvaratu Paar and 1 to 2 miles off Mutwal
Island. It consists of two areas, an outer rocky part 1^ mile in diameter and 4 J to
8 fathoms in depth, and an inner more sandy part 1 mile in diameter and from 2| to
5 fathoms in depth.

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 117

This and a few small neighbouring paars are comparatively unimportant. They
have not, so far as is known, yielded fisheries, but may bear crops of young oysters
and so be of use under a system of cultivation.

Talaivillu Paar.

This lies 1 mile off Talaivillu on Kalpentyn Island, and is 2|- miles from north to
south, and 1 mile wide. The depth is from 4 to 9 fathoms, and there is much deeper
water just over the outer edge. The bottom of the paar is irregular and rocky.

Navakaddu Paar.

This lies about 9 miles south of Talaivillu, less than 2 miles off shore, and 8 miles
due west of Putlam Fort. It is over 2 miles from north to south and 1 mile from
east to west. The depth is 4 to 14 fathoms, and the bottom irregular and rocky.

Jokkenpiddi Paar.

Jokkenpiddi Paar is one of the paars lying oft Chilaw. In this region there are
many little hard patches known as paars, although they rarely bear oysters. Their
exact positions are unimportant, as the whole area is potentially paar-ground.

On the bottom patches of "rock" alternate with sandy areas. Out of 312 dives
on the southern part of the paar, 236 were on " rock," and 76 on sand. The samples
of hard bottom we obtained consist of coarse quartz sand cemented into masses
evidently of recent origin, which may be described as a coarse calcrete (fig. 40),

Fig. 40. Lump of calcrete showing large quartz grains and felspars with fragments of coral, shells
and worm tubes, along with many Polyzoa colonies. From Jokkenpiddi Paar.

together with blocks of dead and some living coral. All the materials are largely
cemented together by colonies of Polyzoa. There are also dark brown ferruginous
nodides of phosphates.

We found a plentiful supply of small oysters (1 to 3 months) on some parts of the

118 CEYLON PEARL OYSTER REPORT.

paar, along with very many dead shells. The living Coral consists of Madrepores and
two species of Turbinaria. We also noticed : — Axinella donnani, Echinostrephus
molare, Ophiothrix sp., Asterina cepheus, Pentaceros lincki, Nardoa tuber -culata,
Filigrana sp., Trophonia sp., Serpulids, Sabellaria, Pagurid (scarlet-maroon, hairy) in
chank shell, and Murex regius, Pearl Oysters, Avicula, Chama, Modiola (suran), and
Vermetus.

Captain Donnan reports that a million and a half of large oysters which he found
on this paar in April, 1878, had disappeared in the November following. This may
become a valuable ground for obtaining a stock for other paars.

Chilaw Paars.

The outer, largest paar lies about 7 miles off the mouth of the Dedera-oya River,
near Chilaw, and is over 8 miles in length and about 2 miles in average breadth. It
has a depth of 8 to 9^ fathoms.

The bottom is sand and masses of calcareous sandstone, which may be described as
a medium-grained calcrete, with a few larger quartz grains up to f inch diameter.

We found considerable quantities of small pearl oysters (6 months old) in large
clusters, attached to one another by byssus and lying on sand, when not attached to
the cemented masses. Amongst other animals found were : — Branched Gorgonids,
with specimens of Avicula radiata, Salmacis dussumieri, and a species of Hesione.

A large supply of young oysters found here by Captain Donnan in April, 1875,
gradually disappeared during the next three years. Although there have been no
fisheries on the Chilaw Paars during recent years, they yielded important fisheries in
the past (1803, 1815, and 1884), and there seems no reason why a crop of pearl
oysters should not mature upon them at any time. We have evidence* that the
Pearl Fisheries controlled by the Singhalese Kings of Kandy were those lying off
Negombo and Chilaw, while those of Manaar and Aripu were in the hands of the
Tamil Kings of Jaffnapatam.

There are also several smaller paars off Chilaw lying nearer the shore, about 3 or 4
miles off land, and averaging about 1 mile each in diameter ; and two further out
north-east of the large paar and about 5 miles off-shore ; in addition, many other
hard patches in this neighbourhood are named as paars by the natives. In fact, there
is a good deal of ground here that might at any time become a " paar" and bear crops
of pearl oysters.

Karkopanni Paae.

This paar lies off Karkopanni, to the North of Chilaw, about 3 miles off-shore, and
at a depth of 7g fathoms. The bottom is rock and sand intermingled, the latter

* From the Singhalese poem, ' Kovul Sandesaya' (about 1460), and Ibu Batuta's 'Travels' (1344),
and also various Dutch records of the eighteenth century. These have been searched by Mr. HoRNEtX,
who expresses his indebtedness to Mr. P. E. Pieris, C.C.S., for translations from the Singhalese.

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAR. 119

greatly predominating. Only a few pearl oysters were found, on the small patches of
rock, when we examined the ground.

The sand here is a coarse, yellow quartz sand, and the " rock " is a coarse, calcareous
sandstone — or calcrete — the large quartz grains, up to an inch in length, heing
apparently embedded in a matrix of carbonate of lime. There are dark, ochreous
patches in places. Out of 187 dives, 140 were on sand and 47 on rock.

Scarcely any living Coral was seen, and no Algse ; amongst the commoner animals
were : — Branched Gorgonids and Hydroids, Terebellids (many, large), Area sp.,
Avicula radiata (on Gorgonids), and Leptoclinum sp.

OOLAWITTI PAAR.

This lies about 8 miles north of Negombo, at a depth of 7|- to 8|- fathoms. On the
bottom coarse, yellow quartz sand predominates; but there is "rock" in patches,
and there some small (6 months) pearl oysters were found.

The " rock " is consolidated sand, of a dark brown colour, as if iron were present in
the cementing material. Mr. Lomas describes it as a " reddish-brown calcrete with
the sand rather loosely united."

On these masses, and penetrating them, are found upright, branched, tough leathery
tubes in abundance. Professor M'Lntosh, in the "Challenger" Report on the
Polychaeta, figures a similar tube from the Gulf of Manaar, and states his belief that
it will prove to be the home of a Eunicid. Mr. Hornell has been able to establish
the correctness of this suggestion, as he has removed two fine Eunicids* from these
tubes.

Negombo Paar.

This lies off Negombo, about 3 miles off-shore, at a depth of 8 to 9 fathoms. The
bottom is sand and patches of "rock" (reddish-brown blocks of calcrete), exactly
similar to that of the Oolawitti Paar. The oysters present when we examined the
paar were probably from 2 to 6 months old, and were mostly attached to the rock,
some in clusters on the sand. They were in considerable abundance.

There is another small paar, south of Negombo, which was found by Captain
Donnan in 1901. It is similar in character to the Oolawitti Paar. Neither of these
Negombo Paars, however, corresponds to the spot off Negombo where we dredged up
young pearl oysters from the " Lady Havelock " in February, 1902. Mr. Hornell, who
has been examining the early charts, is of opinion that the " Lady Havelock " paar
is the original Oolawitti Paar. That does not matter much. What is of real
importance, is to recognise that there are a number of small, more or less hard areas
in the shifting sand, on which from time to time " strikes " of young oysters may
make their appearance, and may possibly grow to maturity, but more usually become
thinned out by their natural enemies or overwhelmed by sand. These small paars
* To be described in Mr. Hornell's Report on the Polychieta, in a later Part.

120 CEYLON PEARL OYSTER REPORT.

close to the deep water are evidently unreliable, and yet may be made use of in
cultivation, and have probably in the past, on occasions, borne a crop of mature
oysters.

The history of the Pearl Fisheries in the past, especially during the nineteenth
century, has shown that : —

(1.) Some of these paars, such as Jagerboom, Kallatidal, Aripu, Anaivelundan,
and others, are practically worthless from an economic point of view.

(2.) Some, such as the Periya Paar, might be used as most valuable sources of
supply of young brood oysters for transplantation ; but cannot be relied upon
to produce an adult stock suitable for fishing.

(3.) Some, such as the great Cheval Paar, with its various sub-divisions, and the
North and South Modragams, the Periya Paar Kerrai, and the Muttuvaratu
Paar, are very valuable and reliable grounds upon which most of the
successful fisheries of the past century have taken place. Others, such as
those off Chilaw and Karativo, are less reliable, but may be valuable on
occasions.

It became clear to us during our work on the " Lady Havelock," when we began to
understand why it is that the Periya Paar is unreliable and the Cheval so much more
satisfactory, that the main hope of introducing constancy of result and a regular
succession of fisheries must rest upon a system of transplanting young strikes or
broods of oysters when they make their appearance upon useless or unreliable paars, to
wherever there is room for them at the time upon ground where we know they will
have a better chance of living and growing to maturity.

This raises the whole question of the causes of death of the Pearl Oyster, the
reasons of the intermittence in the history of the fisheries, and the conditions which
render some paars more reliable than others. As we propose to have a section later
on dealing with our observations and experiments on the Pearl Oyster and ending
with our Recommendations, into which these matters will naturally fall, it will be
sufficient here to give the following summary of our results : —

(1.) The most important agent in causing wide-spread death of Pearl Oysters, both
young and old, in the Gulf of Manaar, is the shifting of sand due to the strong
currents, to the south-west monsoon, and no doubt occasionally to exceptional storms.
We obtained a good deal of evidence as to the manner in which the sand is carried
about and piled up by the currents, and is churned up in places by the heavy seas at
the time of the south-west monsoon, and we made observations as to the effect of
burying oysters of different sizes in various amounts of sand. The successive broods
which have appeared and as regularly disappeared upon the Periya Paar during the
last quarter-century have, there can be no doubt, been overwhelmed by the bottom
currents caused by the monsoon upon the bank which faces the deep water of the
Indian Ocean.

DESCRIPTION OF THE PEARL-OYSTER BANKS OF THE GULF OF MANAAE. 121

(2.) Next in importance come, we consider, the ravages of natural enemies — the
most destructive of which are : —

(a.) Voracious fishes — chiefly Rays (Trygon uarnak) and File-fishes (Batistes

mitis and B. .stcllatus) ;
(b.) Boring Molluscs — chiefly Sistrum spectrum and Binaxia coronata, along

with sjiecies of Nassa, Murex, Purpura and Turbinella ;
(c.) The boring sponge Ctione inclica;
(d.) Boring worms (Leucodore) ;
(<'.) Star-fishes — chiefly Bentaceros and Luidea ;
( f.) Smothering Mollusca — such as Modiola barbata, the " Suran," which weaves

nests and other entanglements around masses of young oysters, and may,

when present in quantity, cause serious mortality.

(3.) There are still three other causes of death that require mention, and may on
occasions be serious, perhaps disastrous, viz. : —

(a.) Overcrowding. — The older are sometimes buried in masses of younger ones.
The young are often piled together in such profusion as to interfere with
each other's nutrition and growth. Thinning out must and does take place.
If it were done artificially all or nearly all might be preserved ; if we leave
it to be effected naturally by survival of the fittest the survivors may be
very few indeed ;

(b.) Disease due to the invasion of parasites — either (1) worm parasites, which
are moderately large and usually not very numerous, and which, unless
abnormally abundant, do little harm ; or (2) the more minute Protozoon
parasites, which may be present in enormous quantities and probably cause
epidemic diseases ;

(c.) Overfishing. — That is, the exhaustion of the breeding stock of the district at
a time when no further supplies of young in the larval stages were being
brought by currents from neighbouring grounds. This will comparatively
rarely happen, and is only likely to be serious during the last year of a
series of fisheries. So long as there are three and four-year old oysters on
adjoining paars which will be fished in the two succeeding years, it is safe to
take every older oyster that can be got off the ground, as those coming on,
although not yet ready to fish, are sexually mature and may be relied upon
to supply spat ; but in the final year of a series, when no further mature
oysters remain for future years, it is important to leave a sufficient stock for
breeding purposes.

In the future, however, if transplanting is adopted, it may be expected
that such a state of affairs as the last fishery of a series with no younger
oysters growing up in the neighbourhood will be very unlikely to recur.

R

122 CEYLON PEAKL OYSTER REPORT.

OBSERVATIONS ON THE SEA AROUND CEYLON, AND ESPECIALLY

IN THE GULF OF MANAAR.

Although we were not prepared to make detailed physical observations on the sea-
water, as I had not considered that necessary for our purpose, we kept a daily record
of such approximate temperatures and densities as we could obtain with ordinary
laboratory thermometers and hydrometers, sufficient to enable us to compare localities
and seasons. During the cruises of the " Lady Havelock" the temperature and specific
gravity were taken twice daily, in the morning after we had started the dredging
operations — generally at 7 a.m. — and in the evening when work was finished, about
7 p.m. After I left, Mr. Hornell continued the records at Galle, and on occasions
at Trincomalee and in the Gulf of Manaar, and took the observations once daily,
between 8 and 10 in the morning, generally at 8.30. We also took all opportunities
of making such observations as were possible on the surface drift of the sea, and
obtained such information as we could as to prevailing currents at different seasons,
as these movements of the water must be of great importance in connection with the
distribution of the young pearl oysters.

During the period (January to April, 1902) of the two cruises in the "Lady
Havelock " and our first inspection of the pearl banks, the sea temperature was
steadily rising. At the beginning of the time, in the Gulf of Manaar, it was about
77° F, in February it averaged 79° F., in March 84° F, and in April 86° F. The
specific gravity was nearly constant at l-0230 in the Gulf of Manaar, while at
Trincomalee, in February, it was lower — varying from 1*017 to l-020.

In July, 1902, the sea temperature at Galle ran up to 86° F., and the specific
gravity was constant at l-0236. Mr. Hornell found that the temperature of the
water in our shaded aquarium tanks was considerably lower (say 3° F.) than that of
the sea outside.

In August the temperature of the water in our aquarium reservoir, taken at 8 a.m.,
ranged from 78° F. to 82° F., the average being 80-37° F

In September the temperatures were taken in the open water at the jetty and
ranged from 81-5° F to 85° F., and the specific gravity from 1-0216 to 1'0220.

In October the temperature at Galle jetty fell from 86° F. to 82 -5° F. ; at Trin-
comalee the range was 84° F. to 89-5° F, and in Tamblegam Lake 87° F. to 90° F.

In November Mr. Hornell was again on the pearl banks and found that the sea
temperatures ranged from 83° F. to 85° F., and the specific gravity from T0200 to
T0227. At Galle jetty at the end of the month the sea temperature was 85° F.

In December, at Galle jetty, the sea temperature was nearly always at 84-5° F.,
the extremes in range being only 8 3 "5° F. and 85° F.

In January, 1903, at Galle jetty, the range was from 82° F. to 84^° F., and the

ON THE SEA AROUND CEYLON, ESPECIALLY IN THE GULF OP MANAAR. 123

specific gravity was close on l-022. At the end of the month, in the Gulf of Manaar,
the sea temperature was 82° F., and the specific gravity slightly above T023.

In February, on the pearl banks, the sea temperatures ranged from 80f° F. to
84f° F, and the specific gravities from 1-0229 to T0239.

In March, in the same locality, the temperature rose from 83° F. to 8G^° F., while
the specific gravities lay between 1'0228 and 1'0234.

Finally, in April, in the same locality, the temperature rose from 86° F. to 88° F.,
while the specific gravity was very constant at l-0228.

These observations, extending over 15 months, show a range of only 13° F. in the
year, 77° F. to 90° F., for the seas around Ceylon ; while in the Gulf of Manaar the
lowest and highest recorded temperatures are 77° F. and 88° F. Thurston found
the temperature at Rameswaram in July, 1888. to vary from 79° F. to 91° F.

The specific gravity in the Gulf of Manaar is fairly constant at about l-023, except
at occasional spots; off Chilaw, on 22nd November, 1903, it was T0194, and on the
Muttuvaratu Paar in the same month it varied about T0200; while at Galle it is
rather lower than the Gulf of Manaar, averaging 1"022, and at Trincomalee it is lower
still, 1"019, and at Tamblegam goes down to 1-015.

Further exact knowledge as to the movements of the water over the pearl banks in
the Gulf of Manaar is urgently needed. On the " Lady Havelock " we had neither
the means nor the time necessary for undertaking this investigation. It is probably
the most important matter still requiring settlement, involving as it does the normal
distribution of pearl-oyster spat. Till we know more accurately how the surface-drift
acts at the chief spatting seasons, we cannot be certain of the source of supply to
particular beds, or of the destiny of the larva? produced from our adult oysters. We
have not yet the means of arriving at conclusions as to the conditions of wind and
weather which are required in order to constitute a favourable spatting season for the
replenishment of say the Periya Paar or the Inner Vankali Paar, where young oysters
frequently appear. Nor are we able to say with certainty whether the Gheval Paar
supplies the Muttuvaratu, or the southern paars replenish the northern, or whether
there is any definite relation as to spat-supply between the Ceylon pearl banks as a
whole and those off Tuticorin on the Indian Coast.

We know that there is a general drift of the water over the banks from south to
north from about the end of April to the end of September, and from north to south
during the height of the north-east monsoon, with intermediate periods of calms and
variable winds from February to April and usually again in November. Now it is
essential that we should have more definite knowledge as to the resulting surface-
drifts in these periods of variable winds between the monsoons, for it is during
November and in March and April that the chief spatting seasons of the pearl oyster
occur. Information in regard to the stronger and more constant currents which may
be sufficient for the purposes of navigation will not suffice for fisheries purposes.
We require to know where floating bodies, liberated at certain spots under known

R 2

124

CEYLON PEARL OYSTER REPORT.

conditions, will drift to during given periods of days at different seasons ; and this
can only be ascertained by systematic " drift -bottle " experiments such as have
recently been made for fisheries purposes in several European seas (see, e.g., 'Fishes
and Fisheries of the Irish Sea,' by Herdman and Dawson, London, 1902, p. 7).
Moreover, it is only after such work has been carried on systematically for two or
three years at least, that it will be possible to determine the course taken by the larval
pearl oysters between the time of hatching and the deposit of spat, and again between
the attachment to floating Algse and the appearance as young oysters on a paar. These
are details which it was impossible for us to settle in the time at our disposal in 1902,
but which will naturally, in the future, form an important part of the work of a
marine biologist resident in Ceylon.

Our inspection barque " Sultan Iskander " towing the divers' boats to a new position.

[ 125 ]

OBSERVATIONS AND EXPERIMENTS ON THE

LIFE-HISTORY AND HABITS OE THE

PEARL OYSTER.

I. Determination op Sex.

At an early date in the investigation it became clear that the pearl oyster is dioecious
or of one sex only — whether permanently so or only temporarily was a matter that
could not be settled in one season, but which Mr. Hornell determined later on in the
Galle laboratory. The dissections made during the cruises of the " Lady Havelock" in
the Gulf of Manaar and in Trincomalee showed that each mature individual functions
as male or female only. In no cases were even stray ova found in the gonads that
were determined as male, nor any spermatozoa in the females — although such traces
of hermaphroditism were carefully looked for.

In the Gulf of Manaar, during February and March, 1902, our dissections showed
a considerable preponderance of males over females, and further work by Mr. Hornell
at Galle showed the same disproportion, to the extent of about 10 per cent, of the
total number examined, during other parts of the year. We have several lists, of
which the following may be taken as a sample. Here out of 210 oysters from four
distinct localities the sex of 158 was determined, 87 being male and 71 female — the
remainder were indeterminable owing either to immaturity or their spent condition.

Date.

Males.

Females.

Spent or
immature.

Locality.

16 October, 1902

5 November, ,,

6 „ „
6 ,, „
' i) »)
9

11
12
14
15
18 ,, „

13
13
9
5
6
5
4
7
4
18
3

9

13
4
3
9
3
6
6
4
9
5

4

4
2

1
2

10
7
8
4

10

Trincomalee.

Cheval Paar.

i) >)

j> it
Periya Paar Kerrai.
Cheval Paar.

>> ))
11 l»
J> »)

Dutch Modragam.

Totals . .

87

71 52

The further question — the permanence of the sexual condition — was one of those
points which could only be settled in a marine laboratory, where the animals could be

126 CEYLON PEARL OYSTER REPORT.

kept under observation from season to season, and formed a part of the work which I
left Mr. Hornell to settle at Galle.

On May 17th, 1902, four of the pearl oysters in our aquarium were found to be
emitting sexual elements, three being determined as males and one as female. They
were marked individually and put in a separate tank, and later in a cage suspended
from a buoy in the bay. On September 23rd two of these verified males were
brought into the laboratory and both proved, on dissection (October 1st), to be still
in the male condition. Over four months had elapsed since the end of the observed
emission of sperms, and the gonads had filled up again for the next breeding season.
The larger individual especially showed vigorous growth in all parts, the shell had
increased from £ to -fa inch, in addition to a great development of marginal processes.
The gonad was fully developed, creamy yellow in colour, and swollen with active
spermatozoa. The two remaining verified individuals were brought in and dissected
on October 3rd, and were found after the 4|- months' interval to be still of their
respective sexes. The male contained ripe spermatozoa, and the female had the
gonad large and swollen with ova in exactly the same condition as those emitted in
May. Spawning might have taken place within a day or two had they lived.

Mr. Hornell has observed the natural emission of the eggs in a 2^- years old pearl
oyster living healthily in the aquarium tanks of the Galle Laboratory. He was also
able, by pouring some of the sea-water charged with freshly laid ova into a tank
containing other pearl oysters, to stimulate three ripe males to discharge spermatozoa.
The first male commenced within two minutes of the addition of the ova to the tank,
and while the stream issued as a milky cloud from the exhalent orifice the animal
at intervals snapped its valves together several times, thus effectively dispersing the
spermatozoa through the water. One minute after the first a second male commenced
to spout and continued to pour out a stream for six minutes. After an hour's interval
it re-commenced for four minutes, followed by occasional puffs for nearly half an hour,
when the emission ceased finally. The third male became active some hours later,
but all proceeded in a similar manner.

These observations show that the ova are extruded direct from the oviducts, by
means of the supra-branchial passage, to the sea. They do not pass any time within
or upon the gills — and do not undergo fertilization within the parent. The develop-
ment of the larva takes place entirely in the sea.

II. Embryology and Early Life-History.

We tried artificial fertilization on several occasions, and although we have not yet
reared the pearl oyster from the egg to a young shelled Mollusc that would be
recognised by the divers, still we have had, in our tanks and under our microscopes,
all stages from the fertilized ovum to free-swimming larvse, similar to those we caught
in the tow-net on the pearl banks, and which again we traced into the attached spat

THE LIFE-HISTORY AND HABITS OF THE PEARL OYSTER, 127

on the Algse. So that we have seen, either in our experimental tanks or in collections
from the sea, every stage from the egg to the adult pearl oyster. Mr. Hornell has
made a careful study of the young stages as observed by him at Galle in May, 1902,
but as we hope to get still further details, the full account of the embryology will be
given later on in this report. It will suffice to state now that the ovum when extruded
is pyriform and floats, after fertilization it becomes spherical. The segmentation is
complete but unequal, and within 2 hours results in an embryo of one large
macromere and six micromeres. After 4 hours, segmentation was completed and
the embryos were swimming freely by means of cilia, while about 20 hours after
fertilization they were in the trochosphere stage, with a well-marked pre-equatorial
band of long cilia, an apical pre-oral tuft and a patch or circlet of cilia at the opposite
pole. As the body elongates, the equatorial band moves further and further forwards
and becomes a pre-oral circlet, most strongly marked along the anterior margin which
becomes the velum. Towards the end of the second day the larva is a veliger, and
the shell has commenced to form posteriorly. On the third day the velum was
considerably reduced in size and the bipartite shell increased, and this brought the
larva to a stage corresponding with the forms we caught in our tow-nets, which
bridged over the gap between the latest stage reared from the egg in the tanks and
the earliest attached stage or " spat."

From a consideration of the sizes of the free-swimming larvae and the youngest spat,
and knowing the age at which the veliger obtains a shell, we are of opinion that
attachment may be made within five days of fertilization. At the same time, from the
large size of some of the free-swimming larvse, it is probable that under certain
circumstances, such as the absence of suitable areas for attachment, the period of
free-swimming existence may be considerably extended.

One of the earliest free-swimming stages was taken in the tow-net on February 2nd,
1903, on Modragam Paar. It shows some slight advance upon the oldest stage reared
in the Galle Laboratory, as rudiments of three branchial filaments and of the otocysts
are present. Otherwise, in the form of the shell, the large size of the velum and the
sub-central position of the digestive gland the two agree. The digestive £>land is
yellowish and granular, the cells being filled with large oil-globules.

In the same haul numbers of an older stage (fig. 41,1.), nearly twice the diameter of
the last, were also present. In these the shell had developed prominent umbones
placed equidistant from the two ends. A few more branchial filaments had appeared
and the velum was relatively smaller. The digestive gland is now conspicuously two-
lobed, and by great increase in size has come to occupy the interior of the umbones
dorsally as well as extending ventrally beyond the plane of the otocysts. The
rudiment of the adductor muscle at the anterior end was also visible.

A fortnight later (16th February), while on the Cheval Paar, in plankton taken
between 8 a.m. and noon, we obtained a great multitude of shelled larva?, many of
which were in a later stage. The shell-valves showed for the first time a slio-ht

128

CEYLON PEARL OYSTER REPORT.

asymmetry, the anterior end being now rather sharper than the posterior (fig. 41, II.).
The velum was greatly reduced, occupying only a comparatively small space between
the anterior adductor muscle and the anterior margin of the gills. The gill filaments
were 6 to 7 in number and of larger size. A posterior adductor muscle was also
present, and the digestive gland, still markedly two-lobed, had increased in size. In

Fig. 41. Free-swimming larval stages of pearl-oyster caught in
the tow-net. I. has the ciliated velum retracted. II. and III.
show the stage at which the larva becomes attached to Alga?.
III. has the mobile foot extended.

Fig. 42. Stages in the growth of the shell after
the attachment of the larva. I. is identical
with the latest free-swimming stage ; o,
anterior, p, posterior end. II. shows the
first formation of prismatic shell (pr.). III.
and IV. show the change in shape and the
byssal sinus (hi/, s.).

several of these larvse the foot was prominent and active, being frequently protruded
and moved about in a tactile manner ; a distinct prominence (the byssal gland) is seen
about the middle of the posterior edge (fig. 41, III.). The otocysts lie close to the base of
the foot, and each is a large clear sac containing 6 to 9 tiny otoliths which were in
constant vibratory motion. The shell is still clear and transparent, with no pigment
and no sign as yet of prismatic structure.

From this stage, ready to make attachment, we pass to the earliest attached stage
("spat"), where the little Mollusc begins to form shell layers of a different character.

Our youngest spat was found clinging to the Hydroid Zoophyte Ca/mpanula/ria
juncea, in November, and later stages, still very young, on the Algae Hypnea
musciformis and species of Sargassum, Cladophora and Polysiphonia on the Cheval
Paar in February and March, 1902. The smallest stage, O'l millim. in antero-posterior
extent, is identical with the oldest free stage referred to above, and is presumably just
attached. From this to a shell length of O'l 75, increase is effected by marginal
additions which are clear and transparent like the larval shell. These additions show,
however, faint circumferential lines, but no prismatic appearance (fig. 42, 1.). The
dark digestive gland shows conspicuously in the umbonal region, and the rows of
branchial filaments are also visible through the thin shell.

THE LIFE-HISTORY AND HABITS OF THE PEARL OYSTER. 129

After a .size of about 0-175 is reached, prismatic shell substance begins to be
deposited marginally, as seen in fig. 42, II., III., IV. The embryonic shell persists, but
the shape of the valve changes to one which is recognisable as the adult type. The
umbones become less prominent, and, as a result of the asymmetrical marginal growth,
become more anterior in position. Even at this early period the byssal sinus (by.*.,
fig. 42) is recognisable, and a verv delicate byssus can be seen anchoring the little
Mollusc. If the spat be attached, as the young stages, in our experience, generally
are, to floating — or for a time rooted — Algae, they seek the under, shady, side of the
branches, and sooner or later drop off and sink to the bottom, being dislodged either
by shaking or by the disintegration of the floating weed The further history will
then depend upon whether they fall upon ground where there is suitable " culch " for
attachment, or upon sandv areas where they probably get buried, scoured out, or
rasped to pieces In- the constant movements of the sand grains. The enormous
number of minute shells of the fry or spat of pearl oysters which we found in some
sandy deposits indicates the extent of the destruction which is going on, and which
might, in part at least, be prevented by artificially increasing the area covered bv
-culch."

We have also evidence that the ground may vary from year to year in the covering
of fine Algse which it affords for the attachment of the young spat. This is shown bv
the following observations : —

On the south end of the Cheval Paar, not far from the Shoal buoy, on February 26th,
1902, we hauled up great masses of mostly green delicate Algre thickly covered with
oyster spat. The Algse proved to be Hypnea musciformis, along with a Chidophora,
a Ceramium, and some Cluetomorplia and Polysip>honia, mostly infested with
Cyanophyceai and various microscopic animals. Much the same assemblage of plants,
but of a redder colour, was found on the Modragam paars on March 10th, and we
also obtained them in smaller amount elsewhere on the pearl banks. In all cases
these weeds supported vast quantities of spat. Later on in the season we found
masses of the weed detached and floating on the surface. This season, however (1903),
Mr. Hoknell finds, after a careful examination of the same grounds in a diving suit,
that the weed is entirely absent, and that the sand in these localities is bare and
shows no spat. This marked difference in the condition of the bottom on two
consecutive years throws an interesting light on the factors which may determine on
occasions the productivity of a bed, and lends support to our contention that putting
" culch " on the bottom at selected spots would lead to an increase in the amount of
spat deposited.

III. The Byssus and Locomotion.

Although the formation of the byssus threads comes more appropriately in the
section on the Structure of the Pearl Ovster, still the connection of the byssus with

s

130 CEYLON PEARL OYSTER REPORT.

fixation, locomotion, and possible migration or transplantation is so close and so
important that we shall give here the results of our experiments on the matter.

Kelaart showed, in 1858, that the young pearl oyster can move from place to
place, can detach its byssus and can re-attach in a new spot. Sullivan Thomas, in
1886, added some fresh observations on young oysters, about |- inch in diameter,
which he found moved up the smooth side of a glass 4 inches in 8 or 9 minutes.
He also made some observations on the byssus, and found that a young oyster,
measuring 1^ inches in diameter, withstood steady tension measured with a spring-
balance till it reached 2f lbs., when the byssus came away at the root. He adds : —
" I conclude that a pearl oyster is not likely to be dislodged by the force of wave
action or current, and that, if it moves, it moves voluntarily."*

Some of our observations on the rapid movements of very young pearl oysters —
much younger than those dealt with by Kelaart and Thomas — and on the readiness
with which they detach and re-attach, were given in the "Narrative" (p. 68), and we
have many others, which, however, it is unnecessary to give in detail. But although
the very young are thus actively locomotive, it has been doubted, and may still be
doubted by some, whether the adult oyster is capable of movement, or even of
re-attaching, if the byssus be torn. Our observations settle this point definitely, as
the following examples show : —

A 2J years old pearl oyster, obtained from the Muttuvaratu Paar on April 11th, 1902,
had the byssus broken by being torn from its attachment to rock. Two days later it
was marked and suspended in a wire-net cage in Galle Harbour under observation.
After 3 days it was found to have re-attached to another oyster in the same cage.
On May 9th it was removed to a tank in the Biological Station, and the new byssus
was then found to be normal, stout-fibred, and of a bronze-green colour. It was then
torn across by force, thus breaking the byssal strands, and was placed in a small glass
dish sunk in the tank. On May 10th an inch and a half of sand was put over the
top of the oyster. On May 1 1th it had freed the ventral margin of the valves from the
sand, and appeared healthy. On May 12th the shells were half uncovered, and the
animal was breathing and feeding normally. On May 13th and 14th the animal still
lay unattached. On May 15th, at 8 a.m., the old byssus was still present; at 9 a.m.
the foot was protruded, and shortly after a new byssal strand had been formed attaching
the oyster to the side of the glass. The old byssus was still retained, but was ejected
during the night, as at 8 a.m., on May 16th, it lay just beyond the byssal sinus of
the shell, and two additional strands had been added to the new cable. The rest may
be quoted from the laboratory diary kept by Mr. Hornell : —

May 17 th, 8.10 a.m. — The oyster had travelled 3^ inches during the night, sloughing
the 3 byssal strands, formed the night before, together with the common root.
The thrown-off byssus remained attached to the glass. At the place of second
re-attachment, 5 pale-coloured strands connected the oyster with the glass.
* ' Madras Journ, of Literature and Science ' for Session 1886-87.

THE LIFE-HLSTORY AND HABITS OF THE PEARL OYSTER.

131

At 7 p.m. — Watching the same individual hy candle light, as it showed signs of
unrest, frequently protruding the tip of the foot, I at length saw the foot thrust out
to the utmost extent (about 1 inch from the tip to the opening of the byssal gland)

"!», fS

~i "3

Fig. 43. Diagram showing the eight successive positions in which a pearl oyster formed new byssus

strands in a fortnight. One-half natural size.

straight in front of the byssal sinus. A strong contraction then shortened the foot,
pulling the animal forwards. For a few seconds it rested, then repeated the operation,
during which the base of the last-formed byssus slipped out from within the shell and
was cast off. The pearl oyster was now free of its mooring, and in the course of the
next hour and a half, after several rests, it travelled l\ inches. It then settled down ;
the foot, after feeling about tentatively, remained quiescent at its fullest extent
(1 inch) for about 5 minutes, then retracted within the shell, revealing a newly formed
byssal thread, clear and almost colourless, attached at the distal end to the glass by
an elliptical disc. After an interval of 7 minutes the foot was again protruded, and
another strand was added in the same way as the first.

May 18th, 8 a.m. — -Two additional strands had been formed during the night,
making 4 in all (rig. 43, III.).

May 23rd, 8 a.m. — During the preceding night this oyster travelled l£ inches
further, re-attaching by 5 new strands, and sloughing the old byssus.

May 2bth, 8 a.m. — Four additional strands have been formed since 23rd inst.
This last move was the fourth re-attachment since brought ashore, and the fifth since
removal from the " paar." At sunset, signs of restlessness were again apparent, the
foot being occasionally extended in a tentative way. At 6.45 p.m. it began crawling
in a definite direction, returning upon its previous course. At the second " step " the
byssal root came away. At 7.15, it was still progressing, and had covered 2 inches
within 30 minutes.

May 26th, 8 a.m. — It had come to anchor 2k inches from the preceding day's
position, with 3 new strands formed (fig. 43, V.).

May 27th. — -Another nocturnal move of 3 inches — 5 new strands.

May 28th. — The longest single journey yet made had taken place during the night,
to position VII. (fig. 43, where the distances are half actual size).

s 2

132 CEYLON PEAKL OYSTER REPORT.

May 20th. — Another of the usual nightly moves. This time a distance of 3f inches
had been covered, 4 strands being formed at the new anchorage — this was the
seventh journey within 14 days. From this date to the time when replaced in the
cage at the harbour buoy, 10 days later, no further movements took place — the animal
at last appearing contented with its position.

Individual No. 2 was of the same age as No. 1, and had a similar history. On
May 9th it was placed in No. 1 tank, and 5-J- days later was found anchored by a
stout, pale-yellow tinted byssal strand to the outside of a glass vessel, against which
it rested. Close by lay its old byssal bundle, with white sloughed-off root. The
attachment had been made (as usual) during the night. Pearl oysters are always
most active after sunset.

May 16th, 8 a.m. — Three new byssal strands were formed during the night. The
older one had now assumed a dark-green colour.

May 17th, 8.30 a.m. — Five new strands have been made since the preceding sunset.

May 18th. — This morning this oyster was removed to another tank, and the byssal
attachment was forcibly torn. It was laid under the inflow-pipe, and within
5 minutes thereafter the foot was protruded, feeling slowly all around. Then, after
one or two momentary withdrawals into the shell, the foot was placed in position,
the anterior part being pressed sucker-like against the tank side. In 4i minutes the
foot withdrew, showing a new byssal thread anchoring the oyster to the tank. The
old byssus was thrown out in the course of the next hour. During the rest of the
day 4 other strands were formed, and 16 more in the course of the ensuing two days.

May 21.vf, 8 A.M. — During the night this oyster had cast off the byssus, travelled
2 inches, and then made a re-attachment by 14 new byssal strands.

May 2ith showed another night march to have taken place. The distance travelled
was 1 inch. The new byssus, the fourth since being brought into the aquarium,
consisted of 3 strands. The next night again showed another move of 2\ inches,
with re-attachment by 9 new stout silvery fibres. After this it made no further
change, remaining affixed to the bottom of the tank till July 3rd, when it was
removed. The length of its fully extended foot was 1{ inches from the tip to the
centre of the mouth of the byssal gland.

The other oysters of this batch took from 5 to 7 days to form their first re-attach-
ment after being brought in from the cages in the harbour. Subsecpiently, when the
water-circulation in the aquarium was improved, re-attachment of freshly introduced
individuals took place much more quickly. Thus, of a number placed in the tanks
on June 1st, at 12.30 p.m., one threw off the old byssus, crawled 2 inches, and
re-attached, all within 2 hours after being brought in. At 6.30 p.m. (sunset) the
same day all the remainder became active — the first sign in nearly every case being
the casting away of the old byssal root. A few crawled a short distance, but the
majority merely protruded the foot, feeling round, and then at once began the work
of forming new cables. At 8.30 p.m., the greater number had made new attachments,.

THE LIFE-HISTORY AND HABITS OF THE PEAK!- OYSTER. 133

and the remainder had thrown ott' their old hvssus and were preparing to attach.
probably waiting for the observers candle to be extinguished.

The next morning all had attached. Several had crawled very long distances; one
had gone nearly to the opposite side of the tank, l'7 inches (the greatest distance
we have seen covered in the J "J hours), another had travelled 8 inches, and a third.
L3 inches. This rapidity of re-attachment under healthy conditions (one within
- hours, the majority within 8, and all within 20 hours) has obviously an important
hearing upon the proposed transplantation operations on the pearl hanks.

Pearl oysters are extremely sensitive to light when preparing to attach, and there
is always difficulty in seeing the actual operation of byssal fixation. While watching
the oysters in one tank, those in another will he fixing, and when the light is brought
to bear upon these last, they will withdraw the foot as soon as the strand they are
engaged upon is finished, and refuse to again protrude until the light is removed.

When the pearl oyster is crawling, while advancing the foot the valves are widely
open. When fully protruded the animal contracts the toot to the utmost, thus
dragging forward the body. At the same time the valves are usually brought
together with a snap, whereby the advance is materially aided.

Our observations show that the disc of attachment of a byssal thread is not formed,
as Kelaart supposed, by a fosset-like expansion of the pedal groove at the tip of the
foot. In reality the pedal groove subserves two distinct functions, the anterior or
distal part being used wholly for locomotion and having nothing to do with hvssus
formation, which is effected by the hinder region of the groove alone. The front end
of this hinder section, at its junction with the locomotor surface and about midway
between the pedal tip and the anterior margin of the byssal pouch, expands to form
an oblong cup-shaped pit or sucker. Behind this again the margins of the groove are
usually curved inwards, meeting medianly, to form an extemporised laterally compressed
cavity, the pedo-byssal tube : anteriorly this communicates with the median sucker-pit
and posteriorly with the byssal pouch.

When the foot is protruded for the purpose of forming a byssal thread, the fore part
of the pedal groove is flattened out to act as a sucker, holding the loot in position.
The lips of the median pit also expand, forming an oval sucker attachment, while the
edges of the hinder part of the pedal surface remain approximated, and may not even
touch the surface to which attachment is to be made. For about 4 to 6 minutes, the
oyster remains at rest in this position, while a secretion is flowing actively from the
byssogenic glands into the extemporised tube along the hinder part of the foot, and so
into the median sucker-pit. The latter is the only spot at which the secretion is in
contact with the exterior. At the end of the time mentioned the distal part of the
pedal surface frees itself, the margins of the proximal tubular region open, and the
foot as a whole is gently withdrawn within the shell, leaving behind a pale, glassy-
looking, laterally compressed thread attached distallv to the extraneous body by an
oval disc, ami at the inner end t<> the base of the byssal pouch. The oval attachment-

134 CEYLON PEAKL OYSTER REPOliT.

disc is the internal mould of the median pit, and the body of the thread that of the
laterally compressed tube formed by the approximation of the margins of the proximal
part of the pedal groove. The secretion forming the byssus hardens upon contact
with sea water. At first it is pale yellowish in colour and almost transparent ; in the
course of 48 hours it becomes opaque and of a deep bronze-green with extremely
lustrous surface. The sensitiveness to bright light of pearl oysters on the move after
sunset, when crawling or when forming new byssal threads, has been noted above.
When visiting the tanks it was noticed that no sooner did the candle flash upon them
than they either withdrew the foot instantly or did so the moment the thread they
were secreting was finished. Locomotion during daylight is very seldom seen, the
habit is undoubtedly to travel after darkness sets in — a time when danger from
predaceous animals is no doubt reduced.

Pearl oysters are equally sensitive to passing shadows during daylight. In the
aquarium tanks the hand passed slowly between them and the sun will cause them to
snap-to their valves ; and on the sea bottom , at a depth of 6 to 9 fathoms, the same
result of a passing shadow can be seen. It must be remembered that on the pearl
banks of the Gulf of Manaar the water is so clear that at the depths named the sea
bottom is brilliantly illuminated when a bright sun is shining.

To some extent the habits of very young spat are exceptional. Thus when the
spat that adhere to floating weed are shaken off into an aquarium tank, they do not,
as older individuals would, lie quiescent on the bottom till after sunset, but at once,
whatever the condition of the light, start crawling up the sides of the tank, and fix
themselves on any objects well above the bottom. Probably an instinctive impulse
makes them endeavour to attain a higher level in order to avoid the risk of being
buried in the sand on the sea bottom. And it is remarkable what comparatively long
distances they cover within a few minutes. We have already shown (" Narrative,"
p. 68) that minute spat from floating weeds can crawl at the rate of 1 inch a minute.

IV. Food and Feeding Habits.

The food of the pearl oyster is microscopic and of similar character to that of allied
Molluscs ; it consists largely of unicellular organisms — spores of Algae, Diatoms,
lnfusorians, and Foraminifera in the main, with smaller numbers of Eadiolarians, the
minute embryos and larvse of various animals, and occasional considerable quantities
of delicate algal filaments (chiefly RhodophyceaB). Non-nutritious particles are also
met with in fair amount, such as the spicules of Alcyonarians and of sponges, with
small numbers of minute sand grains. On the whole, Diatoms, spores, and embryos
are the most important sources of food supply.

Under natural conditions the pearl oyster lies with the right or less convex valve
beneath, and with the posterior edge of the shell elevated at an angle of about 20
degrees. If a detached oyster be placed on the bottom on its left or deeply convex

THE LIFE-HISTORY AND HABITS OF THE PEARL OYSTER. 135

valve, its first movement before making a byssal re-attachment is to protrude the foot
to the utmost extent, and give a violent contraction so as to cant the shell over on to
the right side. When lying undisturbed the pearl oyster separates the ventral edges of
the shell to the extent of about g- inch. This aperture is, however, reduced to a mere
slit by the inwardly directed edges of the pallial lobes from either side which nearly
meet, and interlock by means of the marginal digitate tentacles.

Through this sieve-like slit, guarded by these sensitive branched processes, an
indraught of water is carried by the constant lashing of the cilia covering the gill
surfaces. Any large particle unsuitable for food, or any intruding animal touching the
pallial tentacles, causes the valves to close with a snap. Otherwise a constant stream
of small particles, diatoms, spores, protozoa, and other microscopic organisms, is carried
in with the water flowing towards the branchiae, which function as very fine
strainers, able to sift out and arrest every particle from the incoming current. The
food particles so arrested are carried by the cilia along the furrows to the crest of the
branchial lamella. There the band of specialised cilia forms a path from end to end,
along which the particles pass forwards at a rapid rate to the anterior branchial apex,
where they are carried into the palpar gutter of that side. In all, four ciliated
pathways lead along the branchial crests to the palpar gutters, two on each side.

Occasionally, too, particles find their way into one of the six ciliated paths at the
base of the branchial lamellae. In this case they may either be propelled forward along
this basal pathway, or, as usually happens, be drawn away, after travelling a short
distance, by the ciliary current of the branchial furrows, and so be transferred to the
crest and follow the normal course.

Observations show that the palps can exercise a power of rejection. Thus if there
be sediment in the water, the particles of mud after being sifted out by the gills and
passed to the palps are retained by the latter until enough accumulate to form a tiny
pellet. This is rotated slowly just within the truncated ends of the palps for a tune,
and is then suddenly ejected by a slight movement of the palps on to the surface of
the broad ciliated band that runs outwards to the pallial edge from the base of the
palps. Along this the rejected pellet is carried, round the inside of the pallial edge,
till, arriving opposite the posterior tips of the branchiae, it is thrust out. The
ciliated path there terminates at the distal end of the lip-like twist of the pallial
margin on the ventral border of the exhalent orifice. As the pellet leaves the pallial
edge it comes under the influence of the excurrent stream from the gills, and thus is
carried some little distance away from the oyster.

On the other hand, nutritious particles received on the palpar surfaces from the
branchial ciliated paths are passed on at once to the mouth.

V. Shell-Growth and Repair.

Such subjects as rate of normal shell-growth, power and extent of shell-reparation,
and cases of arrest of growth, are all closely related, and may be considered together.

l 3G

CEYLON PEARL OYSTER REPORT.

1. Size and Growth.

There are two ways of assessing the rate of shell-growth, first the direct one of
keeping marked individuals under observation and noting accurately the dimensions
from time to time, and second the indirect method of visiting certain hanks periodically
and, by taking the average measurements of a number of individuals at each visit,
deducing the average growth from period to period. Both these plans were adopted
during the present investigation, and the following may be stated as a summary of
the conclusions arrived at.

Growth during the first two years of life is very vigorous under healthy conditions
and in the presence of an abundant food supply. During the third year the rate of
increase is reduced, and in the fourth still further so. After that there is little or
no increase superficially, although the shell may grow greatly in thickness.

During the first tbree years the marginal outgrowths or "fintrers" show great
development under healthy conditions. Thereafter there is less and less tendency to
produce these processes, the activity of the oyster's shell-growth in later years being
concentrated upon thickening the nacreous internal layer, largely to counteract the
ravages of boring enemies such as sponges and annelids. With variation in the food
supply, consequent upon the more or less overcrowded condition seen on several of
the " paars," there is marked variation in the rate of growth of the shell (fig. 44).

Fig. 44. Pearl oysters of the same age from the Muttnvaratu and East Cheval paars. to show
difference in size. Traced from a photograph.

Large numbers of measurements of oyster samples from different paars have been
made in the course of this enquiry. It is unnecessary to publish these in full,* so
we give here the results of our tables and such comparisons and conclusions as it
seems possible to draw. It must be stated that in computing the ages of the oldest
oysters now on the pearl banks, we have relied upon the accuracy of Captain Donnan's

* I have in my hands considerable lists, tabulated by Mr. Horneu., which may possibly be inserted a^s
an appendix at the end of the report if it seems desirable.

THE LIFE-HISTORY AND HABITS OF THE PEARL OYSTER. 137

estimate in March, L900. In his report on the inspection of that date he announced
the discovery of two wide-spread falls of spat over the Cheval and Muttuvaratu paars,
which must have taken place about June and December, 1899, respectively, as he
gave the ages, when found in March, 1900, as from 3 to 9 mouths. Consequently
the oysters fished from the East Cheval Paar in the spring of 1903 cannot have been
older than 3 to 3f years, a conclusion Avhich makes the yield of pearls in this last
fishery an eminently satisfactory one considering the comparative immaturity of the
oysters. We must also conclude that, notwithstanding differences in size and
appearance, the oldest oysters on the Muttuvaratu Paar and on the Cheval Paar are
of the same age, as they are grown from the spat which Donnan found in March,
1 900.

A sample of 50 adult oysters from the Muttuvaratu Paar, measured in April, 1902,
gave as the average 2^- X 2^j inches, or 55-50 X 511) millims.* A sample of
38 oysters from the same bank, measured in November, 1902, gave an average of
58"84 X 54-32 millims., by 22-07 millims. in thickness. Twelve oysters from the same
locality, measured in March, 1903, gave an average of 57 "54 X 54'0 millims., by
24"42 millims. in thickness.

These, figures show an increase during 7 months (April to November, 1902) ot
3"34 millims. X 3"32 millims., with a slight decrease during the ensuing 4 months. The
very slight increase during the former period, and the arrest of growth after that, agrees
well with the impression we formed as to this bank from the oysters we have seen.
Coral growths are very rich on the valves along with other incrusting organisms —
Polyzoa, Sponges, Tunicates, and Algse chiefly. The oysters are small but thick,
with no marginal processes or " fingers." If they have ceased to grow superficially,
they are adding to the thickness of the shell. Our field notes say (November, 1902) :
" The pearl oysters on this bank are more thickly crowded than on any other ; their
size is the most stunted of any yet seen, and they are thin and miserable within,
with little food in the alimentary canal in most cases." In March, 1903, when
Mr. Hornell inspected the bank with the diving apparatus, he found that the
oysters were densely crowded together, approximately 125 to the square yard, along
with various other animals, chiefly corals, which were both on and around the oysters.
He noted " The oysters were all small and stunted and unhealthy looking, showing
no vigorous shell growth and no marginal processes. On dissection, it was found that
all those collected had internally the same stunted appearance. The bodies of all were
equally shrunken and thin, the gonads spent or not seasonably developed, and at the
best, extremely small ; indeed all tissues were equally meagre, even the byssus weak
and of few strands." We have other observations, and extracts might be multiplied,
all tending to show that the poorly nourished and diseased condition of the oysters on
the Muttuvaratu Paar is due to overcrowding.

* The first measurement given is always the depth (dorso-ventrally. at right angles to the hinge), and
the second the length (antero-posteriorly).

T

138

CEYLON PEARL OYSTER RETORT.

In marked contrast to the poor growth seen on this bank was the rapid rate of
increase shown on transplantation to a locality under better conditions. Two of our
experiments may be cited to show tin's : —

(1.) A number of oysters collected on April 11th, 1002, from the Muttuvaratu
Paar, were suspended 5 days later in wire-net cages, at a depth (if 3| fathoms, from
the outrigger of a native boat moored in Galle Bay (see fig. 23). By May 9th a
marginal increase varying from 1*20 millim. to 1"50 millim. had been effected, and,
in addition, numbers of long finger-like processes had appeared, an evidence of very
vigorous growth — due, no doubt, to the abundance of food with which the stomach
and intestine of specimens examined were found to be crammed. The internal parts
had undergone a corresponding increase, and the tissues from being thin and shrunken
had now become plump and healthy in appearance. We have the detailed measure-
ments of a number of transplanted individuals, from which we may select three as
samples : —

Specimen B, on April 13th, measured 58"50 X 54-50 millims., and by Mav 9th it
had reached GL60 X 56'70 millims., an increase of 3'10 millims. X 2'20 millims.
during 26 days, and not including the finger processes which had begun to form along
the margin.

Specimen 0 (omitting details), from April 1 5th to May 9th, showed an increase

Fig. 45. Three transplanted pearl-oysters showing rapid growth. I. The dotted line shows the new
shell formed in 23 days. II. The dotted line shows the new shell formed in 21 days.
III. Oyster taken from Muttuvaratu to Cheval, showing a month's growth. All natural size.

varying round the margin from 0'75 millim. to 3'80 millims. ; while if the fingers be
included, the growth during these 23 days was 9 "50 millims. (see fig. 45, I.).

Specimen D was younger, 6 months old, brought from Chilaw Paar. From
April 15th to May 7th the increase was 1 "85 millim. on the average, not including
" fingers." The latter were present when put out at the buoy in Galle Bay. but a

THE LIFE-HISTORY AND HABITS OF THE PEARL OYSTER.

L39

new set, enormously larger, were formed under the more favourable conditions, and
some of these were 10 millims. to II millims. long (fig. 45, II.).

(2.) A number of the same pearl oysters were transplanted the following year,
during the fishery, from the Muttuvaratu Paar, on March 14th, 1903, to the Cheval
Paar, where they were kept under observation until April 19th. The great
improvement both in external size and internal appearance was especially interesting,
since we had an excellent control experiment in the similar oysters left on the
Muttuvaratu, which were examined on April 14th and found to be practically
unchanged. Those taken to the Cheval Paar had the margin thick and entire, with
no new growth and no fingers. After 3G days 4 of them showed the following
increase of size (one of these is shown in fig. 45, III.) : —

A added to margin 7 millims.. and fingers 9 millims. in length.

B

C
D

(i
0
5

K)
12A

A very striking result, due in part possibly to suspension above the bottom ; but
the point is that the animal even when adult will re-act rapidly to improved
conditions.

Some additional records from our lists of the average sizes of oysters from
different localities and of different ages may be of use. They may be conveniently
given in tabular form as follows : —

Locality.

Date.

Number.

Age.

Average of measurements.

South-east Cheval .
North-west Cheval .
South-oast Cheval . .
North Modragam .

November, 1902
March, 1903

5) >>

21
14
34
12

months

11 to 14
11 „ 14
15 „ 18
15 „ 18

millims.

50-57x47-52.
47-64x44-36.
54-41 x 49-75x20-38.
61-17 x54-50x24-28.

These, then, are young oysters in the beginning of their second year, and it will be
seen, comparing those of like age, that the North Modragam are larger than the
South-east Cheval, and the latter are larger than the North-west Cheval.

Those given below are older oysters, mostly in their fourth year (see next page).

T 2

140

CEYLON PEARL OYSTER KEPORT.

Locality.

Date.

Age.

Number.

Average of measurements.

Periya Paar Kerrai .

November, 1902

years

2\ito 3,\-

22

nitllims.

74-36x68-59.

11 1!

March, 1903

•31 orj

33

74-76x67-15x31-25.

North-east Cheval . .

November, 1902

Oil 3 5

* 1 3 11 J 1 3

16

80-25x74-06.

ii ii •

March, 1903

"£ 1) Of

20

76 -05x71 -45x31 -45.

Mid-east Cheval .

November, 1902

21? 3 •"'-

"13 11 "13

8

74-12x67-5.

ii ii ...

March, 1903

qi 03

'i 'i °i

31

75- 15x68-55x31-10.

South-east Cheval . . .

November, 1902

•)ii o .-.

"13 11 "13

36

69-81 x64-44.

ii ii

March, 1903

Ol Q3
"4 11 °4

35

75-77x69-57x31-00.

North-west Cheval . .

November, 1902

911 3 J_
"l2 » J13

6

7 1 • 33 x 67 • 83 (sandy ground).

ii ii •

March, 1903

•31 '3:;
"4 11 °4

3

61-5 x 58 -33x26 -83 (rocky).

South-west Cheval

November, 1902

911 3-3-

"13 l> J13

36

71-25x65-39.

Mid-west Cheval . . .

i» >J

oil 3 ■■

"13 » "13

31

65-68x60-39.

Dutch Modragam .

'1 ))

911 3 *

"13 >1 "13

18

64-0 x61-0.

Muttuvaratu ....

J) ))

211 3 "•

"13 11 °13

—

58-84x54-32.

ii ....

March, 1903

•31 •?:;

°Z ii <>x

57-54x54-00x24- 42.

Taking now the average for all the banks at the November, 1902, and March,
1903, inspections separately, we find that the (say) 3-year-old oysters average
69"9G X 6479 millims. for all localities, and the (say) 3^-year-old oysters average
70/18 X 64 '84 X 29 '33 millims. It is, however, probably not instructive to take an
average for all of the banks, since two distinct types of oyster occur — those
exemplified by the Eastern Cheval and the Muttuvaratu respectively. It is, there-
fore, better to group the Periya Paar Kerrai with the East Cheval in order to
ascertain the normal rate of increase under favourable conditions, at the age
considered : —

Locality.

Average size in millimetres.
November, 1902,
2\l to 3jV years.

Average size in millimetres.

March, 1903,

3] to 3f years.

Periya Paar Kerrai ...

North-east Cheval

The averages at the two dates being

74-36x68-59
80-25x74-06
74-12x67-05
69-81 x64-44

74-76x67-15
76-05x71-45

75-45x68-55
75-77x69-57

74-63x68-53

75-51 x69-18

THE LIFE-HISTORY AND HABITS OF THE PEARL OYSTER.

141

This gives an increase of only 0'8S X 0"65 millim. for the 4 months ending March,
1903, which bears out the statement made above that growth after the third year is
very slow. Comparison with the growth of the much younger (second year)
oysters on the South-west Cheval, from 50'57 X 47 '52 millinis. in November, 1902,
to 54-41 X 4975 millims. in March, 1903, shows how very rapid the increase is at
this age, 3"84 X 2-23 nhllims. in 4 months.

As, however, the shell can grow in thickness of valve as well as in superficial
extent, it is of some importance to consider the weight in relation to age. We are
able to give a table of the weights of shells of one generation of pearl oysters as
determined by Captain Donnan annually from the first year to the time when fished
at 4 and 5 years of age. As after the third year there is but little increase in size,
the figures for the later years may be taken as indicating the additions to the
thickness of the shell.

Weight of Cleaned Pearl-oyster Shells.

Locality and date.

Age.

Number weighed.

Average weight per
pair of valves.

North-west Cheval —

March, 1871

„ 1872

„ 1873

November, 1873 . . . .
March, 1874

„ 1875

year

1
2

3

4 (fished)
5 (fished)

pairs

13

13

50

100

45
47

drams

4
12
19

20.',
24|
30

South-east Cheval —

March, 1874

„ 1875

1876 ....
„ 1877

1

2
3
4 (fished)

33

60

150

51

3.-
13 •

30

The stunted condition of the oysters on the Western Cheval which we saw on the
ground, and have noted elsewhere in this report, is shown by these figures to have
been as marked a quarter of a century ago. While the South-east Cheval produced
shells which at 3 years of age weighed 21 J drams each and at 4 years 30 drams,
those of the same ages from the North-west Cheval weighed only 19 drams and 24|-
drams respectively.

All the above figures, as well as the non-numerical observations which we made
upon the banks during two inspections and a fishery, tend to show that, of the
reliable paars, the Southern and Eastern parts of the Cheval, the Periya Paar Kerrai
and the North Modragam are, at present, those that produce the most rapid growth
and healthy development of the pearl oysters. The conditions at these paars which
seem to determine the good results are :—

142 CEYLON PEARL OYSTER REPORT.

(1.) The local abundance of microscopic food. This was shown by the richness

of the plankton in our tow-net gatherings.
(2.) The absence of competing organisms, such us those that are present in

quantity on coral ground.
(3.) The impossibility of overcrowding, as there are no extensive sheets ot rock

emerging from the sand, and therefore the pearl oysters cannot, at these

localities, form a continuous layer almost hiding the underlying rock, as they

do in some places.

These are all important points, especially perhaps the last. The oysters on these
more favoured grounds, although abundant enough, are not overcrowded, but lie in
separate bunches or little isolated groups. Sometimes, as on the Periya Paar Kerrai,
the foothold consists of little patches of flat rock (see fig. 36, p. 109), 3 or 4 feet in
extent and separated by sandy tracts 2 or 3 yards in width. At other places, as on
the South Cheval, little or no rock appears on the bottom, and the oysters are
attached in bunches to the scattered natural " culch," fragments of dead coral and of
calcretes, broken shells and Lithothamnion masses, lying on the sand. A certain
amount of sandy bottom, interspersed with harder tracts, and with plenty of " culch''
— natural or artificial — scattered over the sand, is probably the most favourable
ground for the Ceylon pearl oyster from the point of view of those interested in the
fisheries. The presence of more culch in many places would, however, be an
improvement. It would give more foothold for new broods of oysters, and at the
same time woidd probably help to stiffen the shifting sand and prevent, in some
degree, the wash-out and turn-over of the surface which is caused by a heavy swell.

The reliable paars which produce less rapid growth and are characterised by their
stunted oysters (the " Koddaipakku " variety of the divers and the Inspectors'
reports) are the Muttuvaratu, much of the West Cheval and the Dutch Modragam.
These are all localities with great stretches of continuous rocky bottom which may be
covered, during favourable seasons, by myriads of pearl oysters closely crowded
together. Thus Captain Donnan estimated, in 1902, that on the sandy East Cheval
(11,804,676 acres) there were 74,41 3, 000 pearl oysters, while on the rocky West
Cheval (10,500,000 acres) there were 123,357,600, showing a much denser population
per acre in the latter case, but not equalling the density on the Muttuvaratu Paar,
where an area of rather less extent (10,206,725 acres) supported in March, 1902, the
enormous total of 277,000,000 pearl oysters — which have since suffered great losses,
due no doubt to their overcrowded condition.

2. Shell- Repair.

Pearl oysters have considerable recuperative power after injury, and can usually
repair damage done to the shell. This is of importance from two points of view, first
in connection with the ravages of some of their natural enemies, and secondly, because

THE LIFE-HISTORY AND HABITS OF THE PEARL OYSTER. 148

of its bearing upon occasional pearl-formation. Many cases were noticed in our field
work where injuries had been effectively repaired, and it is significant that a number
of these were found on the Periya Paar Kerrai during March, 1903, immediately after
the time when we have evidence that Rays {Trygon uarnah) were feeding on the
bank and had crunched up many shells. Some of the oysters we found showed that
fragments of the ventral margin had been broken oft" others that the anterior or the
posterior " ear" had been smashed — all had been repaired more or less perfectlv so as
to enclose the animal and enable the valves to function.

To ascertain the extent and rapidity of the process of repair, a number of
experiments were made both on the pearl banks and at Galle. The following give
the details of a few typical cases : —

(a.) During the removal of oysters from the " Serendib " at Galle in April, 1902, a
2^-year old oyster had a large semi-circular fragment broken from the right valve.
The oyster remained for the next 26 days suspended in a wire-net cage from one of
the buoys in the bay. On May 9th, when brought into the laboratory, the gap was
mended completely and an additional marginal growth of 1 "4 to 2 millims. had formed.
The only departure noticeable from the original condition was that neither of the two
involved radial bands of colour had been continued in the repaired area, the pigment
being spread out instead in a diffused manner.

(b.) In February, 1903, a number of oysters from the Cheval Paar were purposelv
damaged in various ways. When examined on the 23rd, 8 days later, they all showed
extensive repair. In one case 5f millims. of new shell had been added at the damaged
spot, and in two others 3^ millims.

(c.) This was another oyster which had a piece fully 15 millims. in vertical depth
removed from the right valve on February 1 5th. In 9 days a fresh growth, measuring
7 millims. in depth, had formed, while by March 8th the whole of the damage was
made good by a further growth of 8 millims., so that within 21 days a total growth
of 15 millims. depth of new shell had taken place.

(d.) Even more rapid repair was shown by some oysters damaged on February 27th,
due possibly to the fact that they were suspended in the purest sea-water on the
banks for the whole period of the experiment, whereas (b.) and (c.) above were kept
in muddy water off Chilavaturai for several days. The growth shown in (r>.) was
very uniform, and the damage was completely repaired in all cases. Of three
photographed on March 8th (two are shown in fig. 46) : —

No. 1 showed 9 millims. of new solid shell, 12 millims. including the "fingers,"
9 7 1 '3

1 > " ) > ' 11 1 ) 1 1 L " 11 11 11 11

3 7 A 1 2

>s . ii '2 " " >> " " >> u

a surprising growth for 9 days. The colours of the new shell were very brilliant in
these cases, rich brown-red and bright yellow.

144

CEYLON PEARL OYSTER REPORT.

Fig. 46. Two pearl-oysters showing damaged shells repaired in 9 days (February 27th
to March 8th). — Copied from the photograph.

Two other oysters of this same series (d.) were photographed on March 10th.
Within the 10 days, one had formed 6 millims. of new solid shell and 15 millims. in

;

t

m

....
■■?■*":

1^3

i ■ ■■■. ■ ■

rn^st

ijmT-^'i 3

j^:A

JSPJKggp^

■"'-^■1

1

„_

M

jy?&

If?

w*

m 1

JmM *' IPS

■ ■

.

ifflef

"*"»*•*- 3

Fig. 47. Pearl-oyster damaged on February 27th and photographed on March 10th to
show complete repair. The arrows point to the new growth.

all including the "fingers," the other (fig. 47) had formed Hi millims. of shell and
10^- millims. to the end of the " fingers."

(e.) In the case of a number of oysters damaged on April 21st, new growth varying
from 2 to 5 millims. in extent was seen in 2 days.

Many other instances might he given from our note-hooks, but the above will

THE LIFE-HISTORY AND HABITS <>F THE PEAK! OYSTEK. 1.45

suffice to show the rapidity and thoroughness with which the pearl oyster makes
good injury to its shell, and to effectually dispose of any objections that might he
raised to extensive transplantation on the score that the oysters might be damaged
and would not survive the operation.

Observations on the damaged oysters kept in our aquarium tanks at Galle throw
light upon the methods of repair. Damage may either be marginal or superficial. If
the latter, the cause is usually a blow fracturing one of the valves through both
nacreous and prismatic layers and depressing the shell on the distal side of the
break. In a specimen purposely so injured, the mantle-lobe separated from the
proximal part of the shell for some \ inch, leaving a wedge-shaped recess under the
shell-margin at the fracture. In this new position the external pallial epithelium
secreted a fresh deposit of nacre, thus perpetuating permanently the crevice under the
proximal fractured edge.

Cases where the mantle is extensively pierced or lacerated by the injury may be
fatal, not apparently because the animal is unable to make good the damage, but
rather because of the difficulty of keeping out small carnivorous animals such as
worms and molluscs. In several cases, however, we have seen complete recovery from
extensive laceration, the margins of the wound gradually approximating and finally
uniting. While the temporary aperture exists, water may be drawn in through it,
and the tip of the foot is sometimes protruded through the hole in the mantle and
moved round the rough edge of the broken shell, with the result that loose fragments
and dirt particles that accumulate between the mantle and the nacre, and which
probably cause irritation, are removed. No repair-nacre is secreted until the damage
to the mantle is made good.

When a fragment of the shell-margin is broken away, the mantle within is retracted
in proportion to the extent of the damage, not only at the place of injury but for
some distance on either side. Consequently, when the pallial edge begins to form
a new shell-margin, it starts in the uninjured part from a point about -J- to yor mcn
behind (internal to) the former edge. Along the line of fracture the pallial edge
is advanced much closer, or quite up to the margin, beyond which the pallial tentacles
can be seen projecting. This method of starting the new growth behind the existing
edge in the case of injuries is also the normal method of adding to the margin
f the valves in growth. Under normal conditions growth is discontinuous, periods
of activity alternating with what appear to he periods of rest. Each fresh layer
begins from a line about yV inch inside the edge; which process results in the
formation of a number of successive layers of shell with projecting margins outside.
the older overlapping the younger in imbricate fashion. Young rapidly growing
pearl oysters show this imbrication most markedly, especially during the first two
years. As they get older, attrition and the ravages of attacking and incrusting
animals tend to remove the thin projecting margins and .their delicate processes, and
new ones are less frequently formed as the shell ceases to grow in extent hut becomes

U

o

146 CEYLON PEARL OYSTER REPORT.

thicker by deposits of nacre on the inside. The distance apart of the successive
marginal ridges is a good guide to the vigour of the oysters, healthy conditions being
indicated when the distances are considerable, and overcrowding or scarcity of food
when they are massed thickly together, especially at the margin. Many of the
Muttuvaratu oysters show this latter appearance to a marked degree, the edges of
the shell, instead of being thin and delicate as they are on the South-east Cheval,
being comparatively thick and formed of a number of very slight layers of growth,
which do not imbricate, but are massed at the same level, so as to show like the edges
of a pack of cards.

The connection of shell-repair with occasional pearl formation depends upon the
fact that the pearl oyster has to withstand the attacks of various animals — sponges,
worms, molluscs — which bore into the shell. In attempting to repair such lavages
the oyster thickens the nacreous layer, and in some cases piles up pearly excrescences
on the interior of the shell which may be separated as pearls of an inferior quality.
It is probable, also, that when the shell is damaged fine particles, either splinters of
nacre or foreign bodies, gaining access to the interior, may serve as the nuclei of free
pearls. Finally, it must be remembered that shell-growth and pearl-growth are
similar and comparable processes. In both cases limy salts in an organic matrix are
deposited by the living tissues — in the one process on the outside of the body, and in
the other around some internal particle, which in the case of the finest pearls is the
Cestode larval Tetrarhynchus. I shall return to these matters in the later section of
this Iteport, which will treat of pearl formation.

[CEYLON PEARL OYSTER FISHERIES 1903— SUPPLEMENTARY REPORTS, No. LI

REPOIiT

ON

SEA-BOTTOMS AND CALCRETES

COLLECTED BY

Professor HEKDMAN, at CEYLON, m 1902.

BY
J. LOMAS, A.R.C.S., F.G.S.,

LECTURER IN PHYSIOGRAPHY IN THE UNIVERSITY OF LIVERPOOL.

[With ONE PLATE and TEXT FIGURES.]

The samples of sea-bottom, about thirty in number, were dredged mainly from four
districts round the coasts of Ceylon : — (l) About Point de Galle, (2) Trincomalee Bay,
(3) Palk Bay, and (4) the Gulf of Manaar — and most of them were from the last
locality (see map, p. 161).

In addition to the material brought up by the dredge, about twenty specimens of
rock were broken off from the bottom by divers, chiefly from the paars in the Gulf of
Manaar and along the west coast of Ceylon.

The majority of the deposits were obtained from shallow water, 4 to 10 fathoms,
but a few from the Gulf of Manaar and off Galle are from a greater depth.

Point de Galle and Neighbourhood.

In Galle Bay, from depths of 6 to 8 fathoms, shells with sand were dredged. Large
drifted shells, such as Area, Anomia, Ostrea, Cucullcea, and Turritella, mostly in a
rotten condition, made up the bulk of the coarse material, along with large barnacle
valves and a few shark's teeth. The shells were worn, many brown in colour and
polished, indicating a partial conversion into a phosphatic condition. Encrustations
of Nullipores, Serpuloe, and Polyzoa covered the shells, and Clione borings were
common in those shells composed of calcite, while aragonite shells were often not
affected.

r 2

148 CEYLON PEARL OYSTER KEPORT.

The finer material, obtained by sifting through a sieve with a mesh of 1 millim.,
contained from 6T41 to 62 '52 per cent, of carbonate of lime, and included small
Molluscs, Echinoid spines, plates and anchors of Holothurids, spicules of Alcyonium
and Leptoclinum, as well as numerous Foraminifera, siich as Heterostegina, Glolri-
gerina, Textularia, and Spiroloculina, Nullipores and Crista. While the smaller
organisms have a fresh appearance, and are indicative of the life at present in the
district, the larger organisms are mostly dead, and evidently very old.

The inorganic constituents were quartz grains, clear and well rounded, not very
plentiful, kyanite, corundum, zircon, rutile, tourmaline, and mica, A considerable
amount of coal, well rolled, in pieces ranging up to f inch in diameter, is no doubt
due to the proximity of a coaling station.

At Welligain, to the east of Galle Bay, two samples were dredged. ( )ne, a fine
calcareous mud with shells, yielded 76*50 per cent, of carbonate of lime; and another,
obtained from a depth of 4 to 6 fathoms, contained many rotten shells, brown in
colour and bored by Clione, barnacle valves and Halimeda in a fresh condition ; a few
quartz fragments. lingular, ranged up to I- inch in diameter. The fine material in
both hauls consists of a smooth mud which cakes on drying, and contains a few small
quartz grains, tourmaline, zircon, spicules of sponges and Leptoclinum, Holothurian
plates, and diatoms, especially ( 'oscinodiscus. Foraminifera are not common.

Teincomalee Bay.

Off the mouth of Trincomalee Bay. at a depth of 12 fathoms. Foraminiferal sand
was dredged, containing (>7'7 percent, of one form, Heterostegina depressa. Mollusca,
including Area, Troclius and Patella, mostly rolled and encrusted, made up 4"8 per
cent., Corals and Polyzoa (Retepora and Cellepora) 0'2 per cent., Nullipores 8"0 per
cent.. Alveolina (two species) 0'9 per cent., and a few specimens of Echinocyamus.
The material which passed through the Hue sieve, L6;5 per cent,, consisted almost
entirely of small Foraminifera, including Pulvimdina, Textularia, Discorbina,
Miliolina, Cristellaria, Nonionina, Polytrema, and Nummulites. Pteropods and
Alcyonium, Holothurid and Sponge spicules were fairly abundant.

The inorganic constituents include quartz grains, well rounded and ranging up to
3 millims. in diameter, and a black powder, much of which could be removed by a
magnet. The non-magnetic portion Mas fractionated by means of the double iodides
of mercury and barium, and showed a great number of small garnets, corundum,
tourmaline, and kyanite in the heavier fractions, while a little sub-angular quartz and
a few grains of mica made up the lighter portions.

Palk Bay.

North of Rameswaram, in Palk Bay, where shallow water (6 to 7 fathoms) conditions
extend over a great area, and where there is an almost complete absence of currents,

SEA-BOTTOMS AND CALCRETES.

140

a very extraordinary deposit occurs : it consists mainly of concretions, .irregular in
form, with here and there a cast of shell and a few large shells in a fairly fresh hut
broken condition. The shells include Area, Cardium, Chama, Pecten, Murex, Nassa,
and the pearl oyster. No double valves are found and the calcite shells are sometimes
bored by Clione. The concretions on treatment with a weak acid effervesce strongly
and yield a large percentage of fairly coarse sand. Plate 1., tig. 1. shows shells, casts
and concretions from this deposit.

The casts, which contain 64 '80 per cent, of carbonate of lime and 2"2 per cent, of
phosphate of lime, fall to mud when placed in water, and it was necessary to soak in
thin balsam and harden before a section could be obtained. Round the periphery of
the casts is a thin layer of calcite, which moulds itself into the inequalities of the
shell's interior surface ; this is succeeded by
a darker layer, and then the whole interior is
seen to consist of sand grains, quartz, tour-
maline, felspar, and zircon embedded in a
mass of secondary calcite. The sand grains
increase in size <>n proceeding from the
exterior inwards (tig. I), and remind one of
the well-known fact that when grains of
different dimensions are shaken in a basin,
the finer material sinks to the bottom and
the coarser rises to the surface. It is
probable, then, that the grains were rocked
to and fro when in a loose condition inside
the shell, and the cementing took place
subsequently. Afterwards, owing to altered
conditions, the outer shell was dissolved and
the cast left. It is impossible, owing to the
rolled and imperfect condition of the casts, to

tell what shells formerly held the casts, but most of them have a form not unlike
Natica. It is noteworthy that felspars are found in these casts, while they are
absent, as a rule, from sea sands. They were probably embedded soon after breaking
away from the parent rocks and before kaolinisation could reduce them to clay.

The inoreanic material dissolved out from the concretions by acids and fractionated
showed a great preponderance of garnets. The heavier portions were pink in colour
on this account. Other minerals found were corundum, tourmaline, zircon (enclosed
in garnet and free), kyanite, quartz, mica (biotite), and felspar. A number of black
grains were composed of ibnenite.

Further East and North of Adam's Bridge, at a depth of 7 fathoms, a tine Mack mud
occurs which, on analysis, gives: — ■

Fig. 1. Section of internal cast of shell from
Palk Lay : showing the part in contact with
the shell, and sand grains cemented by car-

bonate of lime in the interior.

x 2D.

150

CEYLON PEARL OYSTER REPORT.

Silica 55 '00 per cent.

Carbonate of lime . 3 '50 „

Phosphate of lime. 2-25 ,,

Ferric oxide. . . 4-10

Alumina 15-80 per cent.

Magnesia 275 „

Water and organic matter 16-G0

A few heavy minerals, zircon, tourmaline, and kyanite, occur ; but the bulk is made
up of a fine impalpable mud, smooth to the feel, with minute grains of quartz. Only
a few organisms, one Foraminifer and a small shell fragment, were found in the sample
examined.

Gulp of Manaak.

South of Palk Bay, and separating it from the Gulf of Manaar, is Adam's Bridge.
Rameswaram Island and Manaar Island, which form the two chief links in the chain
of islands almost joining Ceylon with Southern India, consist, according to Foote* and
Walther,1" of calcareous sandstone. This is continued across the Pamban Strait and
forms the "sandstone quay" of the Tonitoray spit on the west and the coastal part
of North Ceylon on the east. The smaller islands between Rameswaram and Manaar
also show a similar rock, while through the passages separating them are loose
drifting sands. The north coast of Rameswaram is fringed by an ancient coral reef,
while living reefs are found in shallow water immediately to the north and to the
south.

South of Adam's Bridge, the Gulf of Manaar stretches as a low sloping beach,
deepening fairly evenly at the rate of about 1 fathom in two miles to 20 fathoms,
where it sinks more rapidly to great depths. Along the west coast the slope of the
shore is more rapid, and deep water is reached sooner. At places along the west
coast, and also south of Manaar Island, spits of sand stretch across the platform,
mainly near the mouths of rivers. They probably result from the detritus brought
down by the rivers, and their general trend towards the north-west may be due to
the combined flow of the streams and the prevailing inshore currents.

On the western shores of the Gulf, and in Palk Bay, the rivers form deltas of large
size, and similar spits of sand extend near the river mouths towards the north-east.
The coasts of India and Ceylon are swept by great marine currents running up or
down the coast according to the monsoons, but owing to the longer duration of the
south-west monsoon it produces greater effects, and all rivers flowing into the Gulf
have a tendency to extend their deltas towards the north.J The sands covering the
floor of the- Gulf become coarser on approaching the west, and there can be no doubt
that the material has been carried down from the high grounds by rivers and then
distributed by currents on the ocean floor. The granulitic rocks of central Ceylon

* ' Memoirs of Geol. Survey of India ' — Geology of the Madura and Tinnevelly Districts,
t Petermann's ' Mittheilungen,' Erganzungslieft No. 102, 1891,
| Foote, <>p. at,

SEA-BOTTOMS AND CALCRETES. 151

are usually fouud in a friable sandy condition,* and thus provide material already
disintegrated which can easily be transported by rivers to the sea. The sand forming
the floor of the Gulf has, in many places, been cemented in situ into calcareous
sandstones or "calcretes," locally known as "paars." In the north part the paars
arrange themselves roughly into three groups, running parallel with Adam's Bridge,
north-north-west to south-south-east. The first line is found at a depth of
3^- to 4|- fathoms, the second at 6 to 8 fathoms, and the third at 9 to 10 fathoms.
Further south, on the West Coast, they have a north and south alignment, here again
following the outline of the coast.

It would appear that the calcretes have grown out radially from centres, the
smaller ones are mainly circular in outline, while the larger ones seem to have been
formed by the growth and fusion of a number of smaller ones. Outliers exist in many
cases near the larger paars, which seem to suggest that they too will eventually
become fused with the main paars. Dredging and diving operations were mainly
conducted in the neighbourhood of the paars, and most of the samples handed to me
for examination were obtained from these localities. Hence the descriptions which
follow readily group themselves round the most important paars.

Periya Paar. — This is the most westerly of the paars, and lies about 20 miles south-
west of Manaar Island. It extends 1 1 miles north-west — south-east, and averages
about 1^ miles in width. Smaller paars exist as outliers at the northern and southern
extremities. The rocky bottom has a depth varying from 8\ to 10 fathoms, with a
thin layer of sand covering the flat surface of the calcrete.

Outside the paar, to the west, the bottom rapidly sinks to 20 fathoms, and further
out 80 fathoms and over are reached. Five specimens of the bottom were dredged in
the neighbourhood of the paar and calcretes from three localities were broken off by
hammers and brought to the surface by divers.

West and South-west of the North end of Periya Paar, at a
depth of 10 fathoms, the contents of the dredge showed many shells in a fresh
condition, Polyzoa, such as Cellaria and Scrupocellaria, Halimeda, and numerous
Nullipores. These were accompanied by a fairly coarse angular quartz sand. The
fine material yielded 27 '64 per cent, of carbonate of lime, and under the microscope
was seen to consist of quartz, sometimes stained with iron, many black grains of
ilmenite and magnetite, tourmaline and zircon, and, as organic constituents, numerous
Foraminifera, Crisia, and sponge spicules.

North-west of the Paar, at 12 fathoms, Foraminiferal sand with shells was
dredged. The shells included Pcctunculus, Area, Chavia, Venus, pearl oyster, and
with these, forming the coarse material, were Heteropsammia, Echinoderms and
a brown Alga. The smaller forms were Foraminifera — Heterostegina in great pro-
fusion— Nullipores, Polyzoa and Serpula;. Only a few clear quartz grains were
present.

* A. K. Coumakaswamy, ' Geol. Mag.,' August, 1903, p. 348.

152 CEYLON PEARL OYSTER REPORT.

F v o m the s u r f a c e of the actual Bank, at 9 fathoms, a quartz sand was
obtained. It contained, in addition, numerous shells, not overgrown with encrusting
organisms, Litlwthammon , brown Algae and horny worm tubes. The tine material —
24 '20 per cent, of carbonate of lime — was principally clear quartz sand well
rounded, and as rarer constituents, tourmaline, garnets, zircon, kyanite, rutile, and
ilmenite.

Comminuted shell fragments, Echinoid spines, and Foraminifera — Heterostegina
principally — made up the bulk of the calcareous portion.

Outside the Paar, to the West, at 20 fathoms, a Foraminiferal sand
containing very little inorganic matter was obtained. The tine stuff yielded 85'8G
per cent, of carbonate of lime. Heterostegina depressa and Alveolina were the
principal constituents, and there were also included Polyzoa — Crista and Scrupo-
cellaria — Alcyoniurn spicules, Holothurian plates, and the spat of young bivalves.

Another haul. Outside, on the West, from 80 fathoms, brought up Foramini-
feral sand with no large forms except a few broken shells. It contained 7G'50 per
cent, of carbonate of lime. Unlike the Foraminiferal sand from shallower depths.
Heterostegina was not abundant, giving place in this group to small Nummulites,
Globigemna, and Textularia ; while Pteropods, the fry of Molluscs, Echinoid spines,
nodes of Crisia, Nullipores, Halimeda, Alcyoniurn and Leptoclinum spicules, and a
simple Coral were the other notable contents.

Turning now to the rocks occurring on this paar, we find : —

The North Part is composed of a fine-grained calcareous sandstone or calcrete.
grey in colour, and containing a considerable number of black grains in patches.'""
The block brought up is thickly encrusted with Polyzoa, both adnate and erect, and
Nullipores, green and white. Shells, such as Chama, are attached to the stone, and
these in turn are covered with encrusting organisms. On the fractured surface, the
centre is seen to be compact, but a thin band of less compact texture separates the
interior from the organisms on the surface. Sometimes the Polyzoa lie directly on
the sandstone, at other times a thin layer of Nullipore intervenes.

The quartz is clear and of fairly even grain, and between the particles the calcite
is seen filling up spaces or lying as thin rods across the grains. A few shell fragments
and Foraminifera occur along with the quartz.

A thin slice examined under the microscope shows quartz, mostly angular, and
averaging about t millim. in diameter, with inclusions of apatite, zircon and
tourmaline, felspars, both orthoclase and plagioclase, showing no signs of kaolinisation,
green tourmaline, shell fragments, and sections of Nummulites.

Calcite occurs as a granular mass filling up spaces between the grains, and often as
curved rods. The rods, as a rule, enclose sand grains ; they are sometimes pitted
transversely, and a dark line in some cases runs down the length of the rod. Brown

* Fooi'E, op. tit., mentions a sandstone containing magnetic iron sand as occurring in Valimukkam
L'litis, un the coast of India.

SEA-BOTTOMS AND CALCKETKS.

15M

origin

chitinous patches are often associated with the calcite rods. Their nature am
will he discussed in the next example from the middle portion of the Paar.

Middle Par t. — Nine specimens, labelled " half way up Periya Paar," consisted
of loose porous calcretes, white in colour and heavily encrusted, and a large Chank
shell rilled with calcareous sand and coated with Polyzoa, Nullipore, calcareous worm
tubes, byssus of pearl oysters, and sponges. Sections of the calcretes were obtained
showing the encrusting organisms in situ. This was a matter of some difficulty,
owing to the friable nature of the material, but on soaking in thin balsam and
hardening, slices were cut and rubbed down on carborundum blocks.

On examining a thin slice with recent colonies on the outside, the surface layers
showed Polyzoan cells arranged in parallel rows, two or three deep, with the avicularia,
vibracula, and opercula in position. The irregular surfaces served to entrap and
retain sand grains and Foraminifera drifting over them. Naturally, only those were
held which fitted closely into the spaces provided, and thus a sifting action took place.
Occasionally two small grains would fill the space in place of one of larger dimensions.
Below the surface layer other cells were seen, nearly all of which contained a grain.
The base and side walls were perfect, but the
top wall had broken down to admit the sand
grain, carrying with it the chitinous oper-
culum. Proceeding towards the centre, suc-
ceeding layers have less prominent walls,
owing to secondary calcite growing from
them in tiny scalenohedra towards the interior
of the cell, and finally we reach a stage when
a thin dark line marking the junction of
adjacent walls, the roughly linear arrange-
ment of uniform grains, and the occasional
remains of chitinous opercula are all that
remain to indicate the former presence of
Polyzoa. Cells which escape being occupied
by sand grains become filled with secondary
calcite showing a radial structure (see fig. 2).

Nullipores sometimes alternate with Poly-
zoa and enclose grains, but it is not difficult
to distinguish between the two even when
structure has been lost. The grains cemented
by Nullipore are sporadic in their distri-
bution, there is no sifting into grains of uniform size, and when they appear in
linear series they are mostly radial, not concentric. The action can be seen in masses
of Lithothamnion, which send out club-shaped extensions from their surfaces. The
spaces between the branches are often filled with loosely-held sand grains, and

x

Fig. 2. Section of C'alcrete with recent Polyzoa
on surface, from Periya Paar Kerrai. The
two upper layers represent sections of
Polyzoon cells, and the lower part shows
sand grains (shaded) in a calcareous matrix
and fragments of the walls and opercula of
the Polyzoa. x 25.

154 CEYLON PEARL OYSTER REPORT.

subsequent growth may enclose them. IAihodomus crypts and worm tubes, when
deserted by their occupants, may also be rilled with sand and become incorporated in
the substances of the Nullipore. We shall return to this subject when discussing a
Nullipore deposit from Chilaw. It is sufficient for the present to point out the
importance of Polyzoa as cementing organisms, and indicate the criteria by which we
can recognise their action.

South end of Periya Pa ar.— Here four pieces were obtained. Three <>f
these were calcretes cemented mainly by Polyzoa, exactly similar to the one
described, and containing grains of quartz, rutile, tourmaline, felspar, corundum and
ilmenite, with shell fragments, Foraminifera, and sponge spicules ; while the fourth
was a piece of dead Coral, very rotten, covered with encrusting organisms, and bored
bv Saxicava.

Cheval Paar. — This paar lies to the south-east of Periya Paar. It is U-shaped,
consisting of east and west arms with a connecting bar at the south.

The east arm is G miles long by L mile broad, and the depth averages GV fathoms.
Outliers to the north are seen at Periya Paar Iverrai, and Vankali Paar, and to the
south lie Kondatchi and Jaggerboom paars.

The west arm measures 4 miles long by \\ to 2 miles broad, the depth is 7 to
8 fathoms. The connecting piece at the south end is 5 miles broad, runs north-east to
south-west with a prolongation at the middle towards the south-east. Two small
isolated paars, North Modragam and South Modragam, extend south-east from the
prolongation.

Seven samples of the dredged material were kept from the parts surrounding the
Paar, and 10 specimens of rock were obtained from the Paar itself and Periya Paar
Kerrai.

Pearl Banks off Ghilavaturai, Q>\ fathoms. — The coarser part of this haul
consisted mainly of drifted shells, including Pearl Oysteij Mactra, Pectunculus, Venus,
Nassa, and Trochus. They were nearly all broken, rotten, and some were bored
by Clione and encrusted with Nullipore, Polyzoa. and Serpuke. Echinids and Starfish
also contributed to the contents of the sample as dredged. The only living organisms
were Polyzoa.

The portion of medium size consisted of clear and milky quartz grains, well rounded
and polished, averaging 5 millims. in diameter, echinoid spines and a few shell
fragments.

The part which passed through a sieve of 1 millim. mesh was mostly quartz sand
with 7 '04 per cent, of carbonate of lime. On concentrating the heavy minerals by a
high-density fluid magnetite, ilmenite and leucoxene, garnets, kyanite, tourmaline,
rutile, corundum, and zircon were found : while in the lighter fractions were
comminuted shells, Nullipores, Foraminifera, Echinoid spines, and spicules of
IlulotJtiiria, Alcyonium, and sponges.

The material has all the appearances of a drifted shell bank swept by strong
currents.

SEA-BOTTtiMS AND CALCRETES. [55

North of Oheval Paar, 7 fathoms. This consisted of a fine quartz sand
with black grains, contained 28'36 per cent, of carbonate of lime, and included a few
encrusted shells and Echinoeyamus.

Son t h-w e s t C orne r o f Che v a 1 P a a r, 8 fathoms. — A fairly coarse shelly
sand, with uniform grains about 5 millims. diameter, made up the bulk of the material.
Natica, Pearl Oysters, Starfish arms, large Heterostegina , Nullipores and spines of
Echinoderms also occurred in the coarser part.

The finer portion contained very little quartz, a little ilmenite and kyanite, sponge
spicules, and the 34 "32 per cent, of carbonate of lime was made up principally of
Foraminifera and young Molluscs.

Middle of South End of Cheval Paar, 7 fathoms, immediately North
of Shoal Buoy. This was nearly all tine sand of a light grey colour.

Pearl < )yster, Pectuncuhis, Lima, Natica, Modiola, and Chank shells were common,
not very fresh and thickly encrusted. Barnacle valves, Sabellaria tubes and
Echinoderms also occurred. Several pieces, about 1 inch long, of a chalky white stone
on cutting proved to be decomposed Nullipore on the outside, and dark brown
compact limestone with quartz and garnets in the interior.

The tine material yielded 22 '20 per cent, of carbonate of lime, and contained quartz,
zircon, kyanite, garnets, tourmaline, corundum, rutile, and mica with shell fragments,
Foraminifera, and sponge spicules.

Shoal Buoy, 3f fathoms, is near the north-west termination of a spit of sand
which extends from Karativo to Cheval Paar.

The bottom consisted of clean white sand with shells, 3 '09 per cent, of carbmiate of
lime, and included a number of small black grains. The largest sand grain was
7 millims. in diameter. The shells were fresh, and some had the two valves in
position.

In addition to quartz, garnets, kyanite, corundum, tourmaline, rutile, and ilmenite.
were a few Foraminifera.

Sou tli Cheval Paar, 5-^ fathoms. — This was made up of a coarse sand with
shells, some of the latter very fresh, with valves in apposition and retaining the
epidermis.

The sand cakes on drying, owing to the presence of a considerable amount of mud.
Pearl Oysters, Modiola, Area, Pectuncuhis, Nassa, Murex, Lithothamnion, and a
shark's tooth, occurred in the coarser stuff, and quartz well rounded, ilmenite,
magnetite, garnet; tourmaline, zircon, and sillimanite were contained in the finer.
No sponge spicules and very few Foraminifera were found.

S o u t h o f Cheval P a a r a coarse quartz sand occurs.

Dealing now with the rocks brought up from the Cheval Paar we find : —

Norther n m o s t end o f E a s t C h e v a 1 is a mass of broken down coral. It
is white in colour, with black grains filling in the pores. There is a slight iron stain
round each grain. Only a few pieces of quartz are found adhering The mass is

x 2

L56 CEYLON PEARL OYSTER REPORT.

bored with Lithodomus, and worm tubes are seen in section on the bottom surface.
Some of these have a few grains of sand attached to the interior of the tul >e.

A few Nullipore patches of a white colour, scarcely distinguishable from the coral,
are attached to the surface, but no Polyzoa.

A thin slice examined under the microscope shows that one or two pieces of shell
and quartz have been enclosed in the walls of the coral, and towards the margin the
thecas have been filled with secondary calcite and numerous Foraminifera.

North Central part of East Cheval and the Middle of West
C h e v a 1 have calcretes exactly like those described from Periya Paar. They are
thickly encrusted with Polyzoa, Nullipore, and worm tubes, and in section evidence of
Polyzoa structure can be seen even in the middle parts of the blocks. The masses
are cavernous, especially near the surface, and large worm tubes adhere to one side
only of the cavities. The cavities have not been formed by boring animals, but are
probably due to influences proceeding from the movements of the worm itself in
setting up ciirrents and thus preventing the growth of cementing organisms in the
immediate neighbourhood. One block which has no worm tubes attached is not
cavernous.

In the S o u t h Central part of E a s t C h e v a 1 , the Central p a r t o f
the Southern portion, North end of West Arm, and in the South -
w est part of the Paar a brown compact limestone occurs. It is usually encrusted
with Polyzoa, Nullipores, and worm tubes, affords attachment to the byssus of the
pearl oyster, and shells, especially Chama, are frequently adherent. In all cases the
limestone is bored by Molluscs and Clione, but only for a short distance from the
margin. It is slightly phosphatic, two specimens examined contained 0'21 and 0"3G
per cent, respectively of phosphate of lime. In section we find a fine granular, light
brown matrix with spots and streaks of reddish material at intervals. Traversing
the matrix are zig-zag and branching lines of clear calcite, evidently filled-in
cracks. Patches of Coral are seen showing clear calcite outlines with dark granular
infilling. Quartz grains, mostly angular, occur, sometimes in patches, at other times
in lines. Zircon, apatite, and garnet accompany the quartz, and magnetite occurs
sporadically, usually showing a reddish border, which is, no doubt, due to the
alteration of this mineral. The ground mass is mostly composed of shell fragments,
Foraminifera, and small broken pieces of Nullipore. Incipient oolitic structure occurs
round some of the grains. I should regard this limestone as the ultimate stage in the
alteration of a coral reef. Coral structure is still to be seen in j>laces, and we can
trace the changes, step by step, by which a coral rock like that occurring at the
north end of East Cheval is converted into compact limestone.

Periya Paar Kerrai. — Samples were obtained from three localities. Two of them
were calcretes, showing Polyzoa and Nullipore structure among the grains, the third
consisted of casts of drifted shells (Plate I., fig. 2).

Casts of pearl oysters were most frequent. All the valves were turned in one

SEA-BOTTOMS AND CALCEETES. 157

direction and overlapping. Lying on the sea floor with their concave surfaces facing
upwards, they have heen filled with sand. This has afterwards been cemented, and
the shells subsequently dissolved. Thus viewing the specimen from one side we see
the smooth cast of the interior of the shells, and on turning over only sand is visible.
Other shells attached to the mass and still retaining their tests are Cardiwm, Pecten,
Mitrex, and Cerithium. Colonies of Polyzoa and worm tubes have attached them-
selves to the smooth surfaces of the casts since the shells were removed.

Dutch Modragam Paar, to the southwards, lies 10 miles due west of Kodramallai
Point. It is 1^- miles in diameter and has a depth of 8 to 14 fathoms.

From this paar two specimens were obtained, one a piece of Madrepore coral about
2 inches thick, with numerous borings of Molluscs proceeding downwards and obliquely
from the upper surface. White Nullipore covered parts of the upper surface, and the
byssus of pearl oysters occurred attached to both the top and bottom.

The other sample was a coarse calcrete, consisting of sand grains very uniform in
size, each measuring 3 to 4 millims. in diameter. The grains were clear, well rounded
quartz and felspar, loosely cemented by carbonate of lime and thickly encrusted by
Nullipore and Polyzoa.

Muttuvaratu Paar lies 5 miles west of Karativo, and has a depth of 5 to 10 fathoms.
Here dead coral, bored in all directions by Molluscs, was brought up. It was covered
by green Nullipore, a few colonies of Polyzoa and worm tubes, and much byssus of
pearl oysters was adherent to both upper and lower surfaces.

Dredging in the neighbourhood, at a depth of 7 fathoms, showed the bottom to
consist of calcareous sand containing 7 8 '36 per cent, of carbonate of lime. Hetero-
stegina depressa was the chief constituent, and some of the larger forms were covered
with green Nullipore. Other organisms present were Alveolina, small univalves,
Diatoms, and spicules of Leptocliiium, Holothurian plates and shell fragments.

Chilaw Paar, the largest paar on this southern part of the west coast, lies 7 miles
west of Chilaw. It is 8 miles in length and averages 2 miles in width. The depth
varies from 9^ to 10 fathoms.

North of the Paar, at 10 fathoms, a calcareous sand was obtained, the finer
material of which on analysis gave 95 '5 per cent, of carbonate of lime. The small
amount of inorganic matter present consisted of quartz grains, '5 milliin. in diameter,
plagioclase felspar, zircon, garnet, tourmaline, kyanite and rutile.

Among the larger organisms present were shells and Nullipores in about equal
proportions, containing such forms as Pecten, Area, Pectuncuhis, Astarte, Turbinella,
Capulus, Nassa, Turritella and Echinoci/amus. Most of these were rotten and
covered with Nullipores, Polyzoa and Serpulse.

The finer material comprised many Foraminifera, including Heterostegina, Polytrema,
Alveolina and Globigarina, Echinoid spines, young Molluscs, Crista, Pteropods, and
spicules of sponges, Holothuria, Alcyonium and Leptoclinum.

South of Chilaw, at 8A fathoms, the bottom was mostly composed of Nnlli-

L58 CEYLON PEAEL OYSTER REPORT.

pores, corals and Sabellaria. Lithotfiamnion fruticulosum was the commonest species
among the Nullipores, and many of the balls were overgrown with Polyzoa and worm
t iihes, and fine sand frequently adhered in the spaces between the branches.

On breaking, the exterior was seen to he white and compact (Plate I., fig. 4), while
the interior consisted of a brick-red spongy mass, almost of a powdery consistency and
containing grains of sand. A thin slice examined under the microscope showed the
white margin to be composed of fresh Nullipore with clusters of quartz grains and
magnetite enclosed and irregularly disposed. Nearer the interior the plant structure
became less distinct, and no trace of structure could be distinguished at the centre.
The spongy core evidently has resulted from the breaking down of the Nullipore and
the staining is due to the hydration of the magnetite. The sand can be accounted for
by irregular growth of the Nullipore enclosing grains attached to the surface.

Two pieces of calcrete from C h i 1 a w P a a r were very like those obtained from
Dutch Modragam, except that the grains were larger and less uniform in size.

Jokenpiddi Paar. — The floor is found to be composed of a very coarse calcareous
conglomerate. It contains large well-rounded clear quartz, felspars, and rounded
pieces of a brown limestone resembling that described from Cheval Paar. Simple
Corals, Clinmn, and tangled masses of calcareous worm tubes cover the block, and
colonies of Polyzoa find lodgment in sheltered cavities. A delicate tracery of Polyzoa
can be seen among the sand grains on a freshly fractured surface (Plate I., fig. 3).

Karkopany Paar, lying off Chilaw at 7 \ fathoms, consists of a medium grained
calcrete with a few large well-rolled pebbles of quartz of larger size. Dark brown
ochreous patches occur in places. Some parts are compact, others loosely cemented.
Polyzoan walls can be seen with the naked eye all through the mass cementing and
covering the grains. Large shells, corals, and worm tubes cover the exterior.

Oolawittee Paar lies north of Negombo, at %\ fathoms. Here two samples were
obtained. Thev consist of a loose sandy reddish-brown material, with a white coating
of Polyzoa completely covering the exterior. Simple Corals, Chama and worm tubes
are attached to the surface, the latter being mostly found lining the walls of cavities.

The rock from Negombo Paar is exactly like that obtained from Oolawittee.
In a thin section we see clear quartz and felspar embedded in a dark brown opaque
matrix. Polyzoa structure is visible, and can readily be traced out from among the
sand grains.

General Remarks.

Li considering the deposits as a whole, one cannot help commenting on the fact
that nothing has been found in them which gives the slightest clue to the character
of the solid rocks forming the bottom of the sea. All are of recent origin and can he
accounted for by the action of causes now at work. Rivers bring down large
quantities of disintegrated material from the interior of the land, particularly in the
season of the south-Avest monsoon ; this is spread over the sea floor by the combined

.SEA-BOTTOMS AND CALCRETES. 159

action of the rivers and ocean currents, and organisms living in the surrounding
.seas are responsible for the calcareous material which forms a considerable proportion
of the deposits laid down in places distant from the shore.

As no rocks of undoubted Tertiary age are found on the adjacent coasts, it would
appear that all through that period the district lias been in a state of equilibrium.
SuBSS* has remarked on the tact that no distinct line can he drawn between the
Miocene and succeeding formations in the east, no break is seen in the deposition,
and newer beds have quietly overlapped those of earlier date. In the absence of any
signs of tectonic movements during the Tertiary period, which, if they had existed,
would certainly have left some traces in the rocks of Ceylon and India, we are driven
to the conclusion that the shallow platform surrounding Ceylon and connecting it
with India on the north is due to the filling up of the sea by detritus derived from
the land (see map, p. 161).

On the west coast of Ceylon, near the mouths ot rivers, spits of sand stretch
across the submerged platform, towards the north-west, while across the Gulf of
Manaar from the opposing shores of .Southern India similar hanks of sand extend to
the north-east. Near the coasts the spits consist of coarse fragments, while further
out the sands become successively of finer grain. Long continued growth of these
spits would result in the formation of a platform arching to the north and produce
exactly the conditions Ave find in the Gulf of Manaar and Palk Bay. Waltheki
records that to the north of Palk Bay, between Calimene Point and Jaffnapatam.
there extends a string of shoals less than 3 fathoms under the surface, and these may
represent a bank in the act of forming.

In describing the deposits it has been shown that in the Gulf of Manaar the loose
material is at the present day being cemented, into calcareous sandstones or calcretes
at the " paars," chiefly through the agency of Polyzoa and Nullipores.

The important part played by Polyzoa in this connection has not hitherto been
recognised. 1 am convinced that many square miles of the rocky paars are due to
this cause alone. < 'oral reefs in all stages of decay, from living reefs to compact lime-
stones showing hut few traces of coral structure, are associated with the calcretes.

If an area of this character were raised above the sea level and acted upon by the
waves of the sea, we should expect the harder paars and limestones to exist as islands,
between which would be areas of loose drifting sand. Such is exactly the structure
of Adam's Bridge — a remarkable chain of islands and shoals which stretches across the
platform from Ceylon to India, According to Foote| and WALTHER§ one of these
islands, Rameswaram, has an ancient coral reef along its northern border, and a

* ' Das Antlitz der Erde,' vol. 2, p. G4*.

t "Die Adamsbrucke uiid die Korallenriffe der Palk-Strasse." Erganzungsheft No. 102 zu Petek-
mann's ' Mittheilungen,' 1891.

I 'Memoirs of the Geological Survey of India.' "On the Geology of the Madura and Tinnevelly
Districts."

8 Op. cit.

160 CEYLON PEARL OYSTER REPORT.

further exposure of coral rock, which has been described as a fossil atoll, lies in the
interior immediately to the North of the Temple of Rameswaram. A large part of
the island is covered by sand dunes which extend as a long spit as far as Thanni-
Kodi on the south-east. These dunes hide the solid rocks of which the island is
built, but a series of trial borings made across the island from north to south, two
miles east of Pamban Town, did not show any southward extension of the coral reef,
but a coarse calcareous sandstone — very modern looking and imperfectly consolidated.
It is unfortunate that a piece of this rock was not available for comparison with the
calcretes found on the paars, but from the detailed descriptions of Foote and Walther,
it corresponds exactly with those found in the Periya and Cheval paar areas.

The chain of small islands east of Thanni-Kodi, and Manaar Island itself, also
consist of similar calcareous sandstones. They are continued to the west across
Pamban Strait and are seen bordering the coasts of Tonitoray Spit. On the east,
according to Richthoven, the low lying plain forming the northern extremity of
Ceylon has a coralline formation for its substratum. Similar rocks can be seen at
intervals all along the East Coast of India, and have been described under the name
of Cuddalore Sandstone. Again, along the West Coast of India, occurs the " littoral
concrete," described by Oldham* as " an agglutinated calcareous shelly grit raised a
little above sea level in several places." " It consists of shells, corals, pebbles, and
sand cemented more or less thoroughly by carbonate of lime.'' " The beds may have
originally been sand spits or beach deposits." All these deposits contain none but
recent shells, exactly like those now living in the neighbouring seas.

SuESst attributes the emergence of Adam's Bridge and the " littoral concrete" to a
negative eustatic movement of the sea level in post-Tertiary times, and brings
together a mass of evidence to show that the negative movement was widespread,
embracing a large portion of the northern hemisphere. He surmises that the
emergence may have been so recent that the great Hindu epic, the Ramayana, which
treats of the building of Adam's Bridge, may be a poetical rendering of events
witnessed by man. Although we have no certain evidence that the Bridge was at
any time continuous, we have historic data to prove that the Island of Rameswaram
was once united with Tonitoray Spit. If, as 1 suggest, the various links in the chain
of islands represent emerged " paars," we have no reason to suppose, judging from the
distribution of those now forming, that they were ever united.

In any case, the barrier, whether continuous or broken, would profoundly influence
the deposits laid down in Palk Bay. Cut off from the currents sweeping up the
coasts from the south, the conditions would be favourable to the deposition of mud,
such as we find covering the floor of the bay, and sand would be confined to the
shores. It will be noticed, however (p. 149), that casts of shells occur in the mud,
and these are composed of sand. The shells have been completely removed, and the

* ' Manual of the Geology of India,' 1893.
t ' Das Antlitz der Erde,' vol. 2, p. 647.

SEA-BOTTOMS AND CALCRETES.

l(il

162 CEYLON PEARL OYSTER REPORT.

casts themselves, in many instances, have been reduced to shapeless spongy masses of
cemented sand. It is not improbable that these shells were filled with sand previous
to the building of the Bridge, when the currents were sufficiently powerful to carry
coarser material.

Some of the deposits, as at Galle Bay and Palk Bay, are evidently very old. They
represent the remains of a fauna where solution and chemical changes have been at
work. The shells left are mostly composed of calcite, not aragonite, and many of
them have become partially converted into phosphate of lime.

Stable minerals such as quartz, garnet, kyanite, tourmaline, and zircon are found
everywhere, whereas the less resistent felspars only occur near the coasts in the Gulf
of Manaar in places where material has been recently deposited, or in calcretes, or in
the interior of shells where they have been preserved from kaolinisation.

My thanks are due to Professor Herdman for much kindly help, and to Mr. C. C.
Moore, F.I.C., of Liverpool, for the care he has taken in analysing some of the
deposits for the purpose of this report.

EXPLANATION OE TLATE I.

Fig. 1. Concretions, shells and casts from Palk Bay.

Fig. 2. Casts of Pearl Oyster and other shells cemented together — from Periya Paar Kerrai.
Fig. 3. Coarse calcrete from Jokenpiddi Paar.

Fig. 4. Nullipore balls, some broken to show red spongy interior. A fragment of Sabellaria is shown
at the extreme right of the middle line — from South of Chilaw Paar.

CEYLON PEARL OYSTER REPORT.

SKA-BOTTOMS & CALCRETES. PLATE I.

Fig. i .

Fk;. 2.

Fig. 3.

Fig. 4.

[CEYLON PEARL OYSTER FISHERIES- 1903- SUPPLEMENTARY REPORTS, No. II.]

LIST

OF

MARINE ALGiE

COLLECTED BY

Professor HERDMAN, at CEYLON, in 1902,

WITH

A NOTE ON THE FRUCTIFICATION OF HALIMEDA.

BY
ETHEL S. BARTON (Mrs. A. GE1T).

[With TEXT FIGURES.]

The list of species represented in the small collection of Algje from the Gulf of
Manaar sent to me by Professor Herdman is as follows : —

CHLOROPHYCE;E.

Codium temie, Kutz.

Geogr. distr. :— Indian Ocean, Red Sea, West Indies.
C. ovale, Zan.

Geogr. distr. : — New Guinea.
C. sp. (? elongatum, Aa).
Valonia, sp. ; a fragment only.
Caulerpa fergusonii, G. Murr.

Geogr. distr. : — Ceylon.
C. plumaris, Ag.

Geogr. distr. : — All tropical seas;
AvrainviUea papuana, Murr. et Boodle.

Geogr. distr. : — Indian and Pacific Oceans.
llalimeda tuna, Lam., forma platjjdisca, Bart.

Geogr. distr. :— Mediterranean Sea, Atlantic, Indian and Pacific Oceans.

y 2

164 CEYLON PEARL OYSTER REPORT.

H. gracilis, Harv., with sporangia (see below, p. 165).

Geogr. distr. : — Indian and Pacific Oceans.
H. opuntia, Lam.

Geogr. distr. : — Tropical zone.

PH,EOPHYCE;E.
Padina commersonii, Bory.

Geogr. distr. : — Indian, N. and S. Pacific and tropical Atlantic Oceans.

Dictyota, sp.

Sargassum ; a fragment only, but Professor Herdman's notes show that a species
is present in great profusion on some parts of the pearl banks, and is of importance in
connection with the attachment of the young pearl oysters.

FLOPJDEiE.
Galaxaura obtusata, Lam.

Geogr. distr. : — Warm Atlantic and N.W. Pacific Oceans.

G, rugosa, Lam.

Geoor. distr. : — Warm Atlantic, Indian and Pacific Oceans.

Aclinotrichia rigida, Decne.

Geogr. distr. : — Red Sea, Indian and N. and tropical Pacific Oceans.

Brachydadia marginata, Schmitz.

Geogr. distr. : — Indian, Pacific and tropical Atlantic Oceans.

Gastroclonium opuntia, Kutz.

Geocx. distr. : — Indian Ocean.

Hypnea musciformis, Lam.

Geogr. distr. : — Mediterranean Sea, tropical and sub-tropical oceans.

Dr. Herdman informs me that this species is of a green colour when alive, and that,

along with a species of Cladophora, a Ceramium, Chcetomorpha and Polysiphonia,

all infested with Cyanophycese, it forms great masses, mostly of a green colour, on

parts of the Cheval and Modragam banks, where it has many young pearl oysters

attached to it.

Laurencia sp. ; young plants.

Neurymenia fraxini folia, J. Ag.

Geogr. distr. : — Indian Ocean.

Polysiphonia sp. ; sterile.

Dasya sp. ; fragment with tetraspores.

Ptilota- fergusoni, Grun.

Geogr. distr. : — Ceylon.

Haloplegma preissii, Sond., var. Jlabelliformis, Harv.

Geogr. distr. : — Australia, Tasmania.

MARINE ALGyE, WITH A NOTE ON THE FRUCTIFICATION OF HALIMEDA. 165

Dr. Herdman noted the presence of a few Algae on the Coral reef at Galle, but
was unable to bring any specimens. From what he says of them, and the rough
sketches, I should suggest that they might be the following species, but it must be
understood that this is mere suggestion : —

Caulerpa racemosa, var. uvifera, J. Ag., or C. sedoides, Aa.

Halimeda tuna, Lam.

Padina commersonii, Hat; v.

Peyssonelia rubra, J. Ag.

Caulerpa plumaris, Ac.

Vanvoorstia spectabilis, Harv.

Corallina sp.

A characteristic of the above is that they were all observed on dead corals.

A Caulerpa, which he noted as occurring on the Pearl banks, in the Gulf of
Manaar, but of which he has no specimen, would appear from his sketch to be
C. scalpel) 'iformis, Ag. Associated with it in quantity was a plant with ovate glossy
dark green leaves, which from the sketch appears to be Haloplula ovata, Gaudich.
They were growing through coarse quartz sand at a depth of 5 or G fathoms, about
10 miles from land.

The field diaries kept by Professor Herdman and Mr. Hornell also contain
records of the following Algae from the Pearl banks : —

Halimeda, tuna, f. platydisca, ( 'hrysymenia uvaria, Udotea flabellata, Dictyurus
purpurascens, Zonaria lobata (?), Rally merda perforata, Laurcncia sp., Polysiphonia
sp., Corallina sp., Acetabularia sp., and "great quantities of Sargassum sp. both on
the bottom and floating on the surface." These are all forms which are quite likely
to have occurred.

Dr. Herdman has asked me whether any comparison can be drawn between the
Algae of the Maldive and Laccadive Islands and those of Ceylon. The only collection
known from the former groups of islands was made by Mr. J. Stanley Gardiner,
and gathered on the coral reefs. It contained 23 species, chiefly of the Indian Ocean
type, more than half of which had previously been recorded from Ceylon. The actual
number of species common to that collection and Dr. Herdman's is only two :
Halimeda tuna, f. platydisca, and Galaxaura rugosa.

Note on the Fructification of Halimeda.

Many of the specimens of Halimeda gracilis, Harv., are in fruit, a condition of
this species which has never been noted or described. The only species of Halimeda
of which the sporangia have hitherto been observed, are H. tuna, Lam., H platydisca,
Decne, and H. macroloba, Decne. In a paper published in December, 1901 ('The
genus Halimeda, Siboga-Expeditie, Monographe LX.,' Leiden) 1 showed that
H. platydisca should be regarded as a form of H, tuna, although Professor Schmitz

L66 CEYLON PEAKL OYSTEE RETORT.

(' Sitzungsber. d. Nied.-rhem. Gesellsch., Bonn, 14. Juni 1880,' p. 14G) maintains that
there are differences between H. tuna and //. platydisca, as regards the position of
the sporangia on the sporangiophores, but he does not give any figures.

As to H. macroloba, the sporangia are mentioned by Zanarejixi (' Icon. Pliyc.
Adriat. et. Medit.,' vol. 3, p. 131) as having been seen by him, and they are stated
to lie similar to those of H. tuna. This remark on the fruits of II. macroloba, Decne,
is inserted by ZANARDINI in his description of Plate CXIL, which represents a
fruiting specimen of II tuna. Hence the reader might be led to imagine that the
fructification figured was that of //. macroloba and not that of H. tuna ; Zanardini,
however, merely emphasizes the point that he had not himself personally collected
the fruiting specimens of//, tuna which he figures, and that he had in his possession
fruiting plants of II. -macroloba, from the Red Sea, a district which was outside the
scope of his memoir. There is, therefore, no figure extant of the fruits of either
II. platydisca or //. macroloba.

The fruits of H. gracilis grow out in small, short tufts from the margin of a joint
(see text-figures), but these tufts are confined to those jooints on the margin at which
the branches of the central strand emerge; and these branches, instead of continuing
their course so as to form a new side-joint, grow out into tufts of fruiting filaments
(figs. 1 and 2). In appearance, the fruiting joints of II. gracilis differ from those of
%H. tuna, which, according to the figures, bear a fringe of fruiting filaments along the
upper margin, and in some cases even in an isolated tuft from the flattened surface of
the joint. It is not quite easy to understand how this Aside, marginal fringe in
77. tuna can arise, since the strand of central filaments, from which the sporangiophores
spring directly, runs up through the centre of the plant and branches inside a joint
to form the side joints. If, as is always stated, the fruiting filaments of Halimcda
arise only from the filaments of the central strand and its branches, then the points
on the margin (or rarely surface) of a joint, where these strands emerge from the
tliallus. are clearly the only points at which fruiting filaments can be borne.

An examination of the fruiting material of //. gracilis shows that the sporangia are
borne, as in II. tuna, on sporangiophores, which form a continuation of the filaments
of the branches of the central strand. According to the system of classification of
species followed in my paper referred to above, the distinguishing feature of
77. gracilis lies in the complete fusion of the filaments of the central strand in pairs
at the apex of a joint, the fused portion branching later trichotomously in the next
joint. When the fused portion is destined, however, to bear sporangiophores instead,
it branches dichotomously to form two sporangiophores, from which the sporangia
emerge all round and form a kind of loose raceme (fig. 3). In the material from the
Pearl banks of the Gulf of Manaar, most of the sporangia are empty, but it has been
possible to find specimens in which the protoplasm still fills the sporangia and the
apex of the sporangiophore. The protoplasm is studded with small, black dots, and
the condition is probably one shortly preceding the ejection of the zoospores.

MAKINE ALGM, WITH A NOTE ON THE FRUCTIFICATION OP HALIMEDA. 167

MM. Derbes and Solier ("Mem. Physiol, d. Algues," ' Compt. Rend.,' Suppl., vol. L,
185G, Plate XII., fig. 3) have figured a condition of the fruits of H. tuna, showing
the sporangiophores and sporangia filled, all hut the actual apex, with a dense, dark

Halimeda gracilis.

Fig. 1. Joints with fructification. Nat. size.
Fig. 2. One joint with fructification, x i.

Fig. 3. Sporangiophores bearing sporangia in a condition shortly preceding the ejection of the zoospores.
The point of fusion of the two filaments of the central strand is shown at the base, x 41.

green protoplasm. In the condition figured in this note, the development has advanced
a stage further, and the dense protoplasm has hecome almost entirely concentrated in
the sporangia and the apex of the sporangiophore.

Of the subsequent escape of the zoospores I can say nothing.

[CEYLON PEARL OYSTER FISHERIES— 1903— SUPPLEMENTARY REPORTS, No. III.]

REPORT

ON THE

GEPHYREA

COLLECTED BY

Professor HEPDMAN, at CEYLON, in 1902.

BY
ARTHUR E. SHIPLEY",

FELLOW AND TUTOR OF CHRIST'S COLLEGE, CAMBRIDGE, AND UNIVERSITY LECTURER ON
THE ADVANCED MORPHOLOGY OF THE INVERTEBRATA.

[With ONE PLATE.]

The collection of Gephyrea, made in Ceylon by Professor Herdman during his
Expedition to inquire into the Pearl Fisheries of that Island, was small, but it contained
at least two specimens of great morphological and systematic interest. These two
specimens, obviously belonging to the same species, I have placed in a new genus
which I have called Centrosvphon, their nearest allies amongst the Sipunculoids being
Aspidosiphon and Cloeosiphon, and I have dedicated the species to its discoverer. The
collection also included many specimens of the coral Heteropsammia michelini, Ed.
and H., with its associated commensal Aspidosiphon corallicola, Sluit. There were
also specimens of the corals Heterocyathus aquicostatus, Ed. and H., and Stephanoseris
rousseaui, Ed. and H., which no doubt contain also their appropriate species of
Aspidosiphon. Further, there were three specimens of As. spiralis, Sluit., a single
specimen of As. steenstrupii, Dies., a single specimen of Cloeosiphon asperg ilium,
Qiiatr., a few specimens of three species of Physcosoma, and a fragment of a
Sipunculus. The Echiuroids were represented by a single specimen of Bonellia
pumicea, Sluit.

SIPUNCULOIDEA.

Aspidosiphon corallicola, Sluiter, Plate I., figs. 1, 2, 3, 11 and 12.

A few specimens of this species, recently described by Sluiter,* were found
living in coiled tubes which penetrate the calcareous skeleton of the solitary coral

* C. Ph. Sluiter, 'Pie Sipuneuliden and Echiuriden der Siboga-Expedition,' Leiden, 1902.

17(1 CEYLON PEAEL OYSTER REPORT.

Heteropsammia michclini, Ed. and H., kindly identified for me by Mr. J. Stanley
Gardiner, The specimens were all in a highly contracted condition, and most of
them showed hardly any portion at all of the introvert, but Mr. Gardiner was able
to place at my disposal a collection of the same species, made off Madras by
Ramunni K. Menon, a former pupil of mine. The external appearance of one or
two of these is shown in Plate I., figs. 1 and 2.

Sluiter's material enabled him to confirm Bouvier's view that the original home
of the Aspidosiphon is a Gasteropod shell on which the young coral comes to rest.
This shell becomes gradually embedded in the stony framework of the Heteropsammia.
The smallest of Sluiter's examples showed the small Gasteropod shell, belonging to
the genera Cerithium, Natica, and others, only partly overgrown and the young
Gephyrean living wholly Avithin the shell. In older stages the corallum spreads until
it reaches and finally grows past the mouth of the shell, but the shell, according to
Sluiter, is not absorbed, but can still be detected if carefully sought for.

On the body, mostly towards the posterior end and therefore, as the animal lies
most remote from the opening, of several of Professor Herdman's examples, were a
number of minute molluscs which Mr. Edgar A. Smith has kindly examined, and he
is of the opinion that they might range with the genus Mysella of Angas. The
animals are, however, so minute, that their exact determination is a matter of great
difficulty.

These were so closely adpressed to the skin of the Aspidosiphon as to indent it,
appearing as little pearls set in a matrix. The advantage they obtained by taking up
such a position is not very evident, but there they were, and as far as one could judge
they were, until Professor Herdman dropped them into his collecting jar, nourishing.

The whole question of such commensalism as exists between the Aspidosiphon and
the coral is an interesting one. Commensalism is usually looked upon as conferring
some mutual advantage on the contracting parties, and one or the other of these
usually seeks the other out. But in the case in question the mutual advantage is far
to seek. It can hardly help the coral to have a large portion of its base burrowed by
a spacious canal, but the fact that the Gephyrean pulls the otherwise immovable
coral about may be, and probably is, an advantage to the Coelenterate. On the other
hand, the Gephyrean gains protection and a home more spacious than the Gasteropod
shell affords. The Aspidosiphon can hardly find, or attract the larval coral to come
to rest on its burrowed shell, and it is unlikely that the larva is especially on the
outlook for such shells as are inhabited by Gephyrea, It seems more probable that
the Aspidosiphon may select for its home a Mollusc shell which already bears a young
coral, but the whole matter seems to demand more careful study. It is certainly
remarkable that three distinct genera of coral, each with but one species, should be
inhabited by three distinct species of Aspidosiphon, and that neither commensal has
hitherto been found apart from the other.

The specimens were obtained at various localities in the Gulf of Manaar (Stns. I.,

CKL'HViJKA. 171

II., IV., &c), and also off Trincomalee (Stns. XX., XXII), and off GaUe (Stns. XXXIX.,
XLIL, and XLIIL).

The Ceylon collection also contains specimens of the corals Heterocyathus mquicostatus,
Ed. and H., and Stephanoseris rousseaul, Ed. and H., showing perforations obviously
made by burrowing Gephyrea.

Aspidosiphon spiralis, Sluiter.

Three specimens of this interesting species described by Sluiter, from the Siboga
Expedition were found living in the shell of three species of Murex, M. fuse*1*,
M. haustellum, and M. tenuispina. The species is interesting because it resembles
Phascolion in" living in Mollusc shells, and because in the slight development of the
posterior shield, and in the absence of a sharp line of division between the shields and
the general surface of the body, it resembles Physcosoma.

The body is highly adapted to its home. Coiled spirally, it closely follows the
contours of the Murex shell. The stout, tough circular anterior shield, on which the
introvert opens excentrically but not quite at the edge, forms an effective guard to the
entrance of the shell. This shield is supported by a stout, very muscular part of the
body-wall which extends for some tenth or twelfth of the total body-length ; after this
the skin becomes extremely thin and transparent. In two of the specimens collected
by Professor Herdman the anterior shields were deep black, in the third it had a
pinkish hue.

Between the Gephyrean and the Mollusc shell was a packing of sand held together
by some secretion. This had a permanent opening at the mouth of the shell through
which the introvert could be protruded.

Aspidosiphon steenstrupii, Diesing.

A single specimen, probably a young one, as the calcareous deposit was not visible.
The musculature agreed, however, with that of this species, and differed clearly from
that of A. truncatus. A. steenstrupii is the commonest Aspidosiphon in the Indian
Ocean. The specimen in question was taken at East Cheval Paar, in the Gulf of
Manaar, from a cavity in a block of coral.

Centrosiphon herdmani, n. g. et sp. — Plate 1., figs. 4-10.

The length of the two specimens, taken at Cheval Paar, Gulf of Manaar, from the
oral shield to the posterior end was 3 centims. The diameter of the oral shield was
3 rnillims., of the posterior shield 2"5 millims. The body between these shields was
of rather smaller diameter, and from each shield the skin seemed gradually to grow
thinner as it passed towards the centre of the body.

The colour in the spirit specimens was in the main a yellowish-gray; with tinges of

z 2

172 CEYLON PEARL OYSTER REPORT.

a chestnut-brown. In one specimen this colour was very marked around the edge oi
the oval shield and extended a little way down the body, further on one side than on
the other, and then gradually faded out to reappear in a slighter degree on the
posterior shield. The same specimen also showed a few irregularly placed and ill-
defined blotches of chestnut colour near the centre of the body.

The proboscis was not fully extended in either specimen. It was protruded from
the centre of the oral shield and extended in one specimen some 3 millims., in the
other somewhat less. The proboscis bears anteriorly several rows of chitinized
processes obviously homologous with the hooks of other forms. Further back it
bears prominent rounded papillae, which are continuous with those on the anterior
shield (fig. 5). This shield, like the posterior one, is separated from the sides of the
body by a well marked rim. The papillae on the anterior shield are uniformly
scattered, but on the posterior shield they run in radiating lines from the rim to the
thickened and somewhat indented centre. The walls of the body are comparatively
smooth, with at best a few low papillae, and these mostly at the two ends.

I opened one specimen with a longitiidinal incision, and the following is an account
of the arrangement of the internal organs. Unfortunately the specimen had had its
alimentary canal broken, and the contents, consisting of sand and fragments of shell,
were all over the place, and much impeded observation.

The longitudinal muscles of the skin are continuous, as in some of the species of
A*pidosiplion, and the interior of that covering presents a smooth glistening gray
surface. The alimentary canal seemed slightly coiled, but it was impossible to
determine if there was a spindle muscle or not.

There are four retractor muscles, two ventral and two dorsal ; only two, and these
are often fused, occur in Aspidosiphon (fig. 8). The ventral are far stouter than the
dorsal, and arise further back at about the level of the junction of the anterior quarter
with the posterior three-quarters of the animal. The dorsal muscles are hardly half so
thick as the ventral. They have their origin a little to right and left of the anus
and at about the same level, which is some 2 or 3 millims. behind the edge of the
oral shield.

At the base of the attachment of the large ventral muscles is a well marked fringe
which obviously gives rise to the reproductive cells.

A single pair of nephridia lie one on each side of the anus. Their external openings
lie close to the edge of the dorsal shield, and probably just behind it.

The introvert of both specimens was half everted, and I cut sections of one of them.
Unfortunately there was a little sand in the interior of the introvert, and some of the
sections were much broken. I was, however, able to make out that the number oi
tentacles is somewhere about twelve to fifteen. Each tentacle is triangular in section,
with a well marked ciliated groove continued down into one of the grooves which line
the beginning of the oesophagus. The transverse section also shows the three spaces
continuous with the body cavity which communicate at the tip, and which by

GEPHYREA. 1 73

allowing the entrance of the ccelomic fluid extend the tentacle. A.s far as I could
make out, the tentacles arise from a ring and not from a horseshoe, and the mouth is
in the centre of the ring.

Behind the bases of the tentacles were little projections of the epidermis hearing
thickened, cuticular projections (fig. 10). These morphologically resemble hooks, but
no part of the tip is bent over, and the whole structure is something like a blunt
speardiead. They are undoubtedly the homologues of the hooks in other unarmed
Gephyrea, and in structure they fairly closely resemble the processes called " hooks"
in Sipunculus amtralis, the only member of the genus Sipunculus which has "hooks."
The spear-head projections were apparently arranged in rings, but with the some-
what broken sections, obliquely cut, it was not possible to definitely make out how
many rings there were. Figure fO also shows the very prominent papillae of the
posterior part of the introvert — the outer layer in the figure — the continuous layer of
muscles, the nervous system cut twice, and the almost completed fusion of the
retractor muscles around the base of the head.

Part of the brain is shown in section in figure 9, which has been cut through the
pigmented, concave layer of cells which forms the eye.

Genus : Centrosiphon, n. g.

The new genus may be characterized as follows : — Sipunculoids with circular
anterior and circular posterior thickened, chitinoid shields; the introvert emerges
from the anterior shield in the centre, and is not inclined to one side more than to
any other, it is quite central ; both shields are separated from the side walls of the
cylindrical animal by a prominent ridge ; the papillse are very prominent on the
introvert, and on it and the anterior shield they are uniformly scattered, on the
posterior shield they are in radiating hues ; anteriorly and just behind the mouth are
rows of spear-head-shaped chitinized projections obviously homologous with the hooks
of other species.

Species: Centrosiphon herdmani, u. g. et sp., Plate I., figs. 4, 5, 6, 7, 8, i) and 10.

With only two specimens at one's disposal, and those of the same species, to
attempt to pick out the specific characters partakes of the nature of prophecy, but,
judging by other and allied Gephyrea, the following, or some of them, will probably
rank as specific characters : — Longitudinal muscles in a continuous sheath ; four
retractor muscles, of these the ventral are very thick and inserted about a quarter of
the animal's length behind the anterior shield, and the dorsal are very slim and
inserted one on either side of the anus, a very little way behind the anterior shield ;
the nephridia are rather dorsal in position and open close to the edge of the dorsal
shield; the tentacles are few in number, some twelve or fifteen, and probablv
surround the mouth as a simple ring; eyes well developed ; no calcareous deposits on
either shield.

174 CEYLON PEARL OYSTER REPORT.

Systematic Position.

Centrosiphon belongs to the same group of Sipunculoids as Aspidosiphon. and
Cloeosiphon. All three genera possess a posterior and an anterior shield, the latter
being placed but slightly in front of the anus and at the base of the introvert.
Centrosiphon differs from Aspidogaster in that its introvert emerges from the centre
of a round shield, quite symmetrically, and in a line corresponding with the long
axis of the body. In Aspidosiphon the anterior shield is shaped something like a
cockle-shell, and the introvert emerges at or near the narrow end and is at an anj-le
with the main axis of the body. Centrosiphon differs from Cloeosiphon in the absence of
the very characteristic calcareous ring round the base of the siphon, with its lozenge-
shaped areas, and in the absence of true hooks, though the latter are represented
by chitinized prominences. It resembles Cloeosiphon in its central proboscis and in
its continuous sheath of longitudinal muscles. In Aspidosiphon the sheath may or
may not be continuous. It differs from both genera in possessing four retractor
muscles, and in the fact that its anterior shield forms a flat platform and not a
radially or bilaterally symmetrical cone.

Cloeosiphon aspergillum, Quatr.

A single specimen, from Stn. XLIV., West of Pantura, 30 fathoms. This species
is common in the Indian Ocean and parts of the Pacific. The " Siboga " took this
form at thirteen stations, and in his account of the Gephyrea collected by the
Expedition on that vessel, Sluiter records his view that the variety javanicum
should be dropped.

Physcosoma agassizii, Sel. and de Man.

A single specimen was taken at Stn. LV., South-west ot Periya Paar, in the Gull
of Manaar ; depth, 11-14 fathoms.

Physcosoma asser, Sel. and de Man.

Three specimens ; one from the Pearl Banks off Aripu (Stn. LIV.), and another
from the Lagoon, Galle. Since my paper in the ' Fauna and Geography of the
Maldive and Laccadive Islands,' this form has been recorded by Sluiter from four oi
the "Siboga" stations.

Physcosoma scolops, Sel. and de Man.

Three specimens of this genus are described as coming "out of a scarlet-ball
sponge (Axinella tubulata), (Jheval Paar (Stn. IX.. 7 fathoms)," and also West of
Periya Paar, 12-14 fathoms, in the same sponge. The species is very common all
over the Indian Ocean from the Red Sea and the East Ooast of Africa to the East
Indies.

GEPHYREA. 175

Sipuuculus, sp.

A fragment of a Sipuuculus, which was insufficient to allow of identification, was
taken at Stn. LVL, south of Dutch Modragam Paar; depth, 8-9 fathoms,

ECHIUKOIDEA.

Bonellia pumicea, Sltjit.

The only Echiuroid in the collection was a Bonellia, from Galle, which I rather
douhtfully identify with Sluiter's Bonellia pumicea (' Natuurk. Tijdschr. v. Nederl.
Ind.,' vol. 50, 1890, p. 111).

EXPLANATION OF PLATE I.

Figs. 1, 2, 3, 11, and 12 are of Aspridosiphon corallicola; figs. 4-10, inclusive, are of

Centrosiphon herdmani.

Fig. 1. .Side view of Aspidosiphon corallicola, Shut, x 10. The introvert is extended, but not quite to

its full extent.
View of anus of the same species, with the thickenings of the anterior shield sloping away

from it.
View of head of the same species showing the ring of tentacles.
Side view of Centrosiphon herdmani, n. g. et sp., with the introvert slightly extended from the

anterior shield, x 8. The chestnut-coloured patches seen on one of the specimens are

well shown here.
A view of the anterior plate and introvert of the same specimen seen from above, x 8.
A view of the posterior plate of the same specimen seen from below, x 8.
A transverse section through one of the papilla? around the base of the head of the same species

showing the chitinous thickening. Highly magnified.
Fig. 8. View of the anterior end of the same species, cut open so as to expose the viscera, x 1C

a., position of anus; d.r., the short, slender dorsal retractor muscles; o\, oesophagus ;

;/./■., genital ridge at the base of the ventral retractor muscles; «., nephridia ; n.c, ventral

nerve cord ; ?■., rectum ; vs., ventral retractor muscles.

Fig.

2.

Fig.

3.

Fig-

4.

Fig.

5,

Fig-

6.

Fig.

7

176 CEYLON PEARL OYSTER REPORT.

Fig. 1). View of a section through the supra-oesophageal ganglion of the same showing e., the eye.
Highly magnified.

Fig. 10. Transverse section through the introvert partly retracted, showing the small group of grooved
tentacles and the rows of chitinized spines. Highly magnified, r., body-cavity, the
isolated portion of this space runs up between the ventral retractors and soon disappears, as
the four retractors fuse to form the muscular sheath in. round the head ; n.r. nerve cord,
which, owing to the retraction of the introvert, is bent, and thus cut across twice; p., papillae
on the lower part of introvert ; s.p., chitinized spines round the base of the head ;
/., transverse sections of tentacles.

Fig. 11. A Hrteropsarninia michelini, Ed. and EL, broken across transversely, showing the head end to the
left, and the tail end to the right of an Aspidosiphon corallicola, Shut, x 2.

Fig. 12. Another specimen of the same, fractured longitudinally. The head end of the Aspidosiphon is
above. The coral shows three pores on its side which communicate with the coiled tube in
which the Gephyrean lives.

CEYLON PEARL OYSTER REPORT

f.LPHYREA PLAI1.

Edwin Wilson Cambridge.

Slli m i LIDS FROM CEM ON

[CEYLON PEARL OYSTER FISHERIES— 1903— SUPPLEMENTARY REPORTS, No. IV.]

REPORT

ON THE

POLYPLACOPHORA

COLLECTED BY

Professor HERDMAN, at CEYLON, in 1902.

BY
E. E. SYKES, B.A., F.L.S.

[With ONE PLATE.]

The large proportion of species described as new in the following pages is not so
surprising as it might appear, since we know but little of the fauna of Ceylon, so far
as the Chitons are concerned.

The collection includes nine species. Of these, three are identified (one doubtfully)
with known forms ; five are described as new ; and, in one case, that of a single
specimen of an Ischnochiton, I have thought it wiser to give no specific name.

Callochiton sublsevis, n. sp. — Plate I., fig. 3.

Shell in shape, sculpture and girdle pattern similar to C. Icevis (Mont.). Colour a
uniform dark red, the interior of the valves being the same colour. The valves
slightly concave in front of the line dividing the lateral and central areas. Valve
slits: anterior 14, median 1, posterior 15.

Length, when alive, about 12 millims.

Hah. : — Navakaddua Paar, 7 fathoms, on Coral (one specimen).

The only salient features that I can trace to sever this form from the European
C. Icevis are the median valves having only one slit, the dark red colour inside the
valves, and the slight concavity before the line dividing the lateral and central
areas.

There is, in the British Museum, a single specimen from the Philippines, bearing
the manuscript name of sublcevis, Carpenter, which probably belongs to the present
species.

2 A

178 CEYLON PEARL OYSTER REPORT.

Callochiton platessa (Gould) ?

A single specimen, not in very good condition, from the lagoon inside the coral reef
at Galle.

Ischnochiton ravanae, n. sp. — Plate I., tig. 4.

Shell elongate, well elevated. Ground colour white, blotched and marbled with
varying colours, black and purple predominating. Sculpture on the lateral areas,
well-marked riblets, generally with an angle in the centre of the ribs, pointing
towards the girdle ; median areas smooth to the eye, but microscopically punctate.
Sculpture of the posterior portion of the posterior valve similar to the lateral areas.
The anterior valve is marked by slight depressed distant riblets, similar to lines of
growth. Interior white, slightly tinted with yellow. Anterior valve with 8, median
1, posterior 15 slits.

Girdle scales broad, flat, thick, strongly striated.

Length, when alive, about 25 millims.

Hab. : — Donnan's Muttuvaratu Paar, 8 fathoms (one specimen).

Ischnochiton herdmani, n. sp. — Plate I., fig. 6.

Shell much elongated, narrow, moderately elevated. Ground colour a greenish-
grey with delicate marking of brown, green, yellow, &c.

The sculpture is difficult to describe ; the anterior valve and posterior area of the
posterior valve are marked by a number of concentric ridges, the edges of these ridges
being broken and roughened ; the lateral areas of the median valves are similarly
sculptured ; the anterior portion of the posterior valve and the median areas are
marked by a number of crossing lines, which give the appearance of the shell having
been stabbed with a broad, blunt dagger ; on the jugal tract these lines lengthen out
and the stab-marks become finer and much more elongate. Interior white, tinged
with pink. Anterior and posterior valves with 9, median with 1 slit.

Girdle wide, with squarish flat, well striated, scales.

Length, when alive, about 40 millims.

Hab. : — The lagoon inside the coral reef at Galle (three specimens).

Related to /. alatus, Sby, but more depressed and differing in sculpture.

Ischnochiton ferreus, n. sp. — Plate I., fig. 5.

Shell ovate, eroded and covered with a brown rusty staining, but apparently
whitish below. Sculptured on the median valves with about ten radiating riblets on
the lateral areas and distant longitudinal riblets on the median areas. The anterior
valve and posterior valve (behind the mucro) appear to be sculptured as the lateral
areas.

POLYPLACOPHORA. 179

Interior white, stained with brown. Anterior valve with 13, median 1, posterior
13 slits.

Girdle with broad, flat, finely striated scales ; some scales do not show the sculpture,
but this is, I think, due to erosion.

Length, when alive, about 15 millims.

Hab. : — Trincomalee (one specimen).

Ischnochiton, sp.
A single specimen, from the Gulf of Manaar.

Craspedochitou laqueatus (Sby). — Plate I., fig. 7.

Chiton laqueatus, Sby : 'P. Zool. Soc.,' 1841, p. 104.

: Reeve, 'Conch. Icon.,' Plate XX., fig. 135.

Craspedochitou laqueatus, Sby : Shuttlewoeth, 'Bern. Mittheil.,' 1853, p. 67;
Pilsbry, ' Man. Conch.,' vol. 14, p. 285,

Angasia tetrica, Carpenter: Pilsbry, 'Man. Conch.,' vol. 14, p. 287.

Hab. : — South of Modragam Paar (Stn. LXIV.), 5 fathoms ; and North of the Gulf
of Manaar (Stn. LXIX), 7-13 fathoms (several specimens).

I am unable to sever the Philippine shell from the Ceylon form described as
A. tetrica. The species has a varied generic history, as it forms the type of Craspedo-
chiton, Shuttlew., Angasia, Carpenter, nee White, and Phacellozona, Pilsbry.

A single specimen from " Palk Bay, Februaxy, 1902," I refer here with some
doubt, as it is slightly more elevate, the posterior valve shows no trace of the
radiating lines, and there are other minor differences.

Acanthochites penicillatus (Desh.) — Plate I., fig. 2.

Chiton penicillatus, Deshayes: 'Moll. Reunion,' p. 41, Plate VI., figs. 8-10.

Chiton (Acanthochites) penicillatus, Desh. : Martens in Mobius' ' Reise Mauritius,' p. 300.

Acanthochites penicillatus, Desh. : Pilsbry, 'Man. Conch.,' vol. 15, p. 15, Plate IV, fig. 84,

Plate VIII., figs. 29, 30.

Hab. : — Gulf' of Manaar (two specimens).

I identify the Ceylon with the Mauritian shell with a little doubt, as I know the
latter only from figures and descriptions.

Tonicia pectinoides, n. sp. — Plate I., fig. 1.

Shell ovate, broad, elevated. Colour, reddish to yellowish-green. Lateral areas
well raised. The central areas and anterior portion of the posterior valve are
sculptured with longitudinal, broad, flattened riblets, the interstices marked by

2 A 2

180 CEYLON PEAEL OYSTER REPORT.

minute, crossing riblets, somewhat as is frequently seen in the Pectinidte. Anterior
valve, posterior portion of posterior valve, and lateral areas marked with flattened
nodules, those on the median valves being fewer in number, irregular in size, and
more Avidely separated. Mucro posterior and much elevated.

Interior white. Median valves with 1, anterior with 8, posterior valve with
numerous small slits.

Girdle microscopically setose.

Length, when alive, about 18 millims.

Hab. : — Pearl-banks in the Gulf of Manaar and deep water off Galle (Stn. XL.),
34 fathoms (two specimens).

EXPLANATION OF PLATE I.

Fig. 1. Tonicia pectinoides, n. sp.

Fig. 2. Acanthochites penicillatus (Desh).

Fig. 3. Calldchitoti siibkevis, n. sp.

Fig. 4. ' Ischnochiton rammce, n. sp.

Fig. 5. Ischnochiton ferreus, n. sp.

Fig. 6. Ischnochiton herdmani, n. sp.

Fig. 7. Craspedochiton lagueatus (Sby).

CEYLON PEARL OYSTER REPORT.

POL.YPLACOPHORA. PLATE I.

«.

""m^

■

J Green, del. etlitk

.

Species 01 Pui vplacophora.

[CEYLON PEARL OYSTER FISHERIES— 1903— SUPPLEMENTARY REPORTS, No. V.]

REPORT

ON THE

HOLOTHURIOIDEA

COLLECTED BY

Professor HERDMAN, at CEYLON, in 1902.

BY-
JOSEPH PEARSON, B.Sa,

SCHOLAR IN ZOOLOGY IN THE VICTORIA UNIVERSITY, AND NATURALIST TO THE
ULSTER FISHERIES AND BIOLOGY ASSOCIATION.

[With PLATES I. to III.]

The Holothcjrians obtained by Professor Herdman during his expedition to
Ceylon have proved to be a very interesting and extensive series.

The collection consists of 70 specimens, which are distributed amongst 10 genera
and about 30 species. Of these I find that seven are new to science and there are
also at least two new varieties. One of the new species requires the formation of a
new genus, Havelockia, near to Colocldrus in the Dendrochirotse.

In the main I have followed the classification and nomenclature adopted by
Ludwig (12).* I have, however, taken Jeffrey Bell's (16, 17) suggestion with
regard to the generic name Actinopyga.

The following is a list of the species in the collection : —

Synapta striata, Sluiter. Thyone sacellus (Selenka).

Synapta beselii, Jager. Thyone (?) fusca, n. sp.

Synapta, sp. (?). Thyone (?) hornelli, n. sp.

Synapta, sp. (?). Thyone (?) calcarea, n. sp.

Cucmnaria tricolor, Sluiter. Phyllophorus cebuensis (Semper).

C. furbimta (Hutton). Actinocucumis donnani, n. sp.

C. imbricata (Semper). Oolochirus quadrangularis, Lesson.

C. conjwigens, Semper. Col. quadrangularis, var. mollis, nov.

Thyone fusus, var. papaensi*, ThtSel, Col. doliolum (Pallas).

* The numbers in brackets refer to the List of Literature on p. liOG.

182

CEYLON PEARL OYSTER REPORT.

Colochirus, sp. (?).

Havelockia herdmani, n. gen. & sp.

Adinopyga mauritiana (Quoy and Gaimard).

Actinopijga serratidens, n. sp.

Holothwia ku/rti, Ludwig.

H. monncaria (Lesson).

H. vagabunda, Selenka.

H. tenuissima, Semper.
H. marmorata (Jiiger),
H. aim, Jiiger.
H. gallensis, n. sp.
Stichopus chloronotus, Brandt.
St. chloronotus, var. fusms, nov.
St. variegatus, Semper.

In addition to these, the field notes made by Professor Herdman and Mr. Hornell
show that they observed two species (or varieties) of Psoitis, the one black and the
other grey, on the East Cheval Paar.

So far as I am aware, this is much the largest collection of Holothurians that has
been yet obtained from the seas of Ceylon. Until about twenty years ago no
Holothurians had been definitely recorded from that coast. Owing mainly to the
work of Drs. Paul and Fritz Sarasin, of Mr. Edgar Thurston, of Madras, and
others, the number on record had lately reached the total of 37 species. Professor
Herdman's Holothurian collection, in addition to a number of the forms previously
known, contains at least 20 species and distinct varieties which are now recorded
from Ceylon for the first time, thus bringing the total number of known species and
varieties up to 57, as shown in the following list. The first column gives those
species reported by Mr. Thurston (19) from the Gulf of Manaar, the second those
described by Professor Jeffrey Bell (8), the third shows those collected by
Drs. P. and F. Sarasin, chiefly at Trincomalee, and described by Professor Ludwig (9),
the fourth those few collected by Professor Haeckel, and described by Dr. Walter
(18), and the fifth column gives those collected by Professor Herdman in 1902, and
described in the present report.

List of Ceylon Holothurians.

Name of Species.

Synapta beselii, Jiiger

S. grisea, Semper

S. recta, Semper

S. striata, Sluiter

& sp. (? n. sp.)

S. sp. (? n. sp.)

Chirodota rufescens, Brandt . . .

C'h. duhia, Semper

Haphdactyla molpadioides, Semper
Hap. australis, Semper . . . .

Thubston.

Bell.

Sakasin.

Haeckel.

Herhman.

X

X

X

X

X

X

X

XXX

X

X

HOLOTHUEIOIDEA.

List of Ceylon Holothurians— continued.

183

Name of Species.

Thurston.

Bell.

Sabasin.

Haeckel. Hebdiian.

X

X

C. tricolor, Sluiter

X

X

X

ft conjungens, Semper

X

'Tlii/onc sacellus (Selenka)

X

X

Th. fusus, var. papiiensis, Theel ....

y

Th. (?) fusca, n. sp

X

Th. (1) horndli, n. sp

X

TA. (1) calcarea, n. sp

X

Phyllophorus abuensis (Semper) ....

X

X

Artinomcumis donnani, n. sp

X

Colochirus quadra/ngularis, Lesson ....

X

X

Col. quadrangularis, var. mollis, nov. . . .

X

X

X

( 'ol. sp. (?)

X

Havelockia hcrdmani, n. gen. et sp.

X

Actinopyga mauritiana (Q. and G.)

X

X

.-W. in Hid ris, Q. and G

X

X

Act. echinites, Jager

X

X

. let. seiratidens, n. sp. . . ....

X

Act. sp. (Walter)

X

Holothuria argus, Jager

X

X

X

X

X

X

H. impatieus, Forskaal

X

X

//. midaatjei, Bell

X

X

X

//. iiunitiairiit, Lesson

X

X

X

H. vagabunda, Selenka

X

X

H. scabra, Jager

X

X

184

CEYLON PEARL OYSTER REPORT.
List of Ceylon Holothurians — continued.

Name of Species.

Thurston.

Bell.

Sabasin.

II A ECKEL.

Herdman.

H. pardalis, Selenka

H. fusco-cinerea, Jiiger

H. edulis, Lesson

H. imitans, Ludwig

H. marenzelleri, Ludwig .... . .

H. kurti, Ludwig

H. tenuissima, Semper

Stichopus variegatus, Semper

St. chloranotus, var. fuscus, nov. . .

X
X
X
X
X

/

X

X

X

y

X
X

y

X

Geographical Distribution.

An examination of the geographical distribution of the Ceylon Holothurians shows
clearly that they are typically Indo-Pacihc forms ; and that their recorded
occurrences form an etjuatorial belt, ranging from the east coast of Africa to the
South Pacific.

It will be seen from the following table that only four of the 53 named species
have been found in the North Pacific, namely, Holothuria fusco-cinerea, Colochirus
armatirs, Thyone sacellus and Actinocucumis 1}ii>ioi ; while the Atlantic fauna is only
rejtresented by three species, which occur, two in the Caribbean Sea {Holothuria atra
and II. impatiens) and one at the Cape of Good Hope {Colochirus doholum).

The table shows the recorded distribution of Ceylon Holothurians in the yreat
oceans of the world. The concentration in the right-hand columns, which indicate
the Indo-Pacific region, is most marked.

Name of Species.

Si/impta beselii, Jiiger
S. grisea, Semper .
S. recta, Semper.
iS. striata, Sluiter .

c
c

5

<

c

a
«a

-t-3

<

CO

o
'o

X

Ph

CJ

eg
'u

K

Ph
GO

E
CJ
01

u

o

C

.5

M

E. Indies
(Malay Seas).

Australasia.

X

X
X

X
X
X
X

X

HOLOTHURIOIPEA.

185

Name of Species.

Chirodota rufescens, Brandt . . .

Chit: dubia, Semper

Haplodaetyla molpadioides, Semper .

Hap. australis, Semper

Cuewmaria semperi, Bell ....

C. twbinata (Hutton)

ft tricolor, Sluiter

ft imlmcata (Semper)

ft conjimgens, Semper

Thyme sacellus (Selenka) ....
Th. fusns, var. papumsis, Theel . .

Th. (?) fusca, n. sp

Th. (?) hornelli, n. sp

Th. (V) calcarea, n. sp

Phyllophorus cebuensis (Semper) . .
Actinocucwnis typica, Ludwig . .
Adinocucumis donnani, n. sp. . .
Colochirus qiiadrangvlaris, Lesson .
Col. quadra ngularis, var. mollis, nov
Colochirus doliolwm (Pallas) . . .
Col. armatvs, Marenzeller. . . .
Havelockia herdmani, n. gen. & sp. .
Actinopyga mavrUiana (Q. and G.).
Act. miliaris (Q. and G.) . . . .

Act. echinites, Jiiger

Act. lecanora, Jiiger

Act. serratidens, n. sp

Ilulothuria argns, Jiiger . . . .

//. atra, Jiiger

II. cmswrea, Ludwig

//. impatiens, Forskaal . . . .

H. ondaafjei, Bell

H. marmorata, Jiiger

//. monacaria, Lesson

■4

«4

Ph

&

G

a -a

I— I e3

2 B

18G

CEYLON PEARL OYSTER REPORT.

Name of Species.

N. Atlantic.

i S. Atlantic.

N. Pacilie.

, S. Pacific.

Indian Ocean.

E. Indies
(Malay Seas).

1

Australasia.

H. vagabunda, Selenka

X

X

X

H. scabm, Jager. .

X

X

H. pulchella, Selenka

X

X

X

//. spinifera, Theel .

X

//. partialis, Selenka .

X

*

H. fusco-cinerea, .Tiiger .

X

X

X

//. edulis, Lesson .

X

X

II. imitans, Ludwig

X

//. marenzelleri, Ludwig

X

//. lturti, Ludwig .

X

X

II. gallensis, n. sp. .

X

//. tenuissima, Semper .

X

X

X

Sticlwpus variegatux, Semper

X

X

St. chloronotus, Brandt.

X

X

X

St. chloronotus, var. fuscus, nov. .

X

f wi^li finallv +n f

ll'PSS

m

V

t.L a n I

-.« in V

S'AfPttQr

IV IT PR

n\i A XT

Yr\r n 1

niviii < r

inn +*\

examine this most interesting collection, as well as for the advice and assistance which
he was always willing to give in the solution of points of difficulty.

HOLOTHURIOIDEA

Order : PAIIACTINOPODA.

Family: SYXA 1TI I>.E.

Synapta striata, Sltjitek (10) — Plate I., fig. I.

Eight specimens from the outei part of Yard Cave, Trincomalee (Stn. XXVI.),
2-8 fathoms.

Lengths range from 15 millims. to 85 milium The smaller specimens are evidently
in a contracted condition.

The following is Professor Hebpman's description taken from the living animal ; —

IIOLOTHUKIOIDEA. 187

"Living amid sponge branches. Colour, striped lilac on a white ground. The five
rays of the body are marked by five narrow white bands. The region between these
rays is marked with numerous delicate lilac stripes forming a pattern which is
variable in different individuals. The tentacles are used for progression and are
flattened for two-thirds of the way from the apex."

There are 13 tentacles present, each having f 9 digits. Plate I., fig. 1, shows the
flattened extremity of a tentacle, as drawn from the living animal in Professor
Herdman's note-book.

There are about 1 8 Polian vesicles in the specimen dissected, (J being large and
the rest smaller. There is one madreporic canal. The alimentary canal is looped.

The deposits agree with Sluiter's figures. I have found, however, that some of
the anchor plates differ from the usual form in having smooth holes. There are also
present in the skin numerous miliary granules which are arranged in groups of six or
seven, having typically one central granule surrounded by numerous granules in a
circle. This species appears to be very closely allied to S. racta and & ivrfivisa.

This species is now recorded from Ceylon for the first time.

Distribution : — Java and Ceylon.

[Synapta beselii, Jager.

A large Synapta, measuring G feet in length, was found by Mr. Hoexele at Galle.
The specimen has not reached me, but the size and description agreed so well with
.$'. beselii, already known from Ceylon, that there can be little doubt as to the species.

Distribution : — Indian Ocean, Philippines, South Pacific and East Indies.]

Synapta, sp. (? n. sp.).

This is a fragment from the south west of Palk Bay (Stn. XVIII.), 7 fathoms, in
mud. Only the posterior portion of the body remains.

The fragment is 50 millims. long, and the body is evidently in a very contracted
condition. All the internal organs are torn away. Still the specimen clearly belongs
to a species of Synapta.

Deposits : — The anchor plates are in all cases imperfect. The plates are covered
with short spines and are perforated by a large number of small holes of various
sizes. The anchors are large, and the handle is serrated. So far as I am able to
determine, these spicules do not resemble those of any known species, but the
incomplete state of the specimen does not permit me to make a definite decision
with regard to its identity, nor to describe it more fully.

Synapta, sp. (? n. sp.).

One specimen from Galle. This specimen is in a poor state of preservation, so that
1 cannot be absolutely certain as to its identity.
There are 1 "J tentacles, each having 5 digits.

•2 E 2

188 CEYLON PEARL OYSTER REPORT.

Deposits : — The anchor arms are not always symmetrically placed. They are
slightly serrated. The anchor handles are strongly serrated. The anchor plate is
perforated irregularly — the arrangement differing in different plates. There are
several larger holes with serrated margins, and also several smaller smooth holes.
There is no handle to the plate. There are also a number of short rods scattered
throughout the skin, having a small hole at each end.

Neither this nor the preceding species can possihly belong to any of the species
previously recorded from Ceylon, viz., S. striata, S. recta, S. grisea, and & beselii,
and in their spicules they seem to differ from all known species of the genus.
Consequently, they probably both of them represent new species, but they are too
fragmentary to be descrihed.

Order: ACTINOPODA.
Family : DENDROCHIROT.E.

Cucumaria tricolor, Sluiter (15).

One specimen from near Donnan's Paar (Stu. LX.), Gulf of Manaar, 28 fathoms.

Length of body, 30 millims.

The following is a description of the colour of the living animal as noted by
Professor Herdman : — "The interambulacra are violet-purple, and the ambulacra
appear as light yellow bands, on which are situated pedicels of a deeper yellow."
There are also a couple of sketches in the notes which agree with Sluiter's figures
and show the characteristic form of body.

The body is curved so that the anus is thrown on to the dorsal surface, thus making
the trivium longer than the bivium. The pedicels on the trivium are arranged in
three well-defined series, each series being composed of two or three rows. The
pedicels on the bivium are not so easily determined, and only on careful examination
can an irregular and feebly marked single row of scattered pedicels be distinguished
on each side of the dorsum.

The mouth, which is terminal, is surrounded by five very prominent rows ol
protuberances which terminate the five ambulacra of the body. These prominences,
of which there are three in each row, do not appear to be tube feet, but are more
probably papilla). The anus is armed with five teeth, and is surrounded by four
papilla? similar to those surrounding the mouth. Gonads are not present.
No deposits were found in the skin.

The calcareous ring is small and consists of ten pieces, without any posterior
prolongations. It agrees with Sluiter's drawing.

The only serious difference between Sluiter's description and the above is with
regard to the calcareous deposits. The Ceylon specimen has no deposits ; but since

HOLOTHURIOIDEA. 189

it has been kept for several months in a solution of formol, it is by no means safe to
attach importance to this fact.

There is a slight disagreement in the arrangement of the pedicels. Sluiter's
specimen had five well-marked series of pedicels, those on the trivium consisting of
five or six rows, and those mi the bivium of two or three rows. But the smaller
number of pedicels on the Ceylon specimen may be explained by the fact that it is
evidently much younger, being only one-fifth the size.

There is also a slight difference of colour. The pedicels of Sluiter's specimen were
red ; those of the Ceylon specimen were a " deep yellow." This is probably of no
importance.

This species is now recorded from Ceylon for the first time. Its known distribution
is Aril Islands and Ceylon.

Cucumaria turbinata (Hutton), Plate I., figs. 2-6.
Labidodesmus turbinata, Hutton (3), 1878.

One specimen from Gulf of Manaar (Stn. VI.), 6 to U fathoms.

Hutton described this species under the name Labidodesmus turbinata, but Theel,
in his " Challenger" report, places it in the genus Cucumaria, with the remark that a
re-description of the animal is necessary.

fSo far as I can ascertain from Hutton's scanty description, the Ceylon specimen is
identical with his New Zealand species, the type specimen of which is now in the
British Museum. Professor Herdman has kindly examined for me the British
Museum specimen, and compared it with my description and drawings of the Ceylon
specimen, and was convinced that both belong to the same species. As Hutton, in
his description, said nothing about deposits, Professor F. Jeffrey Bell kindly allowed
me to examine a small piece of the skin of the British Museum specimen. I found
that there were no deposits present, but since the specimen has been preserved for
25 years, it is by no means safe to conclude that the skin of the living animal was
devoid of calcareous spicules. I am now, therefore, able to supply what Theel stated
was necessary, namely, a re-description of Hutton's species.

The following is a description of the Ceylon specimen, which I believe to be that
species : —

Length, 25 millims. Greatest width, 12 millims.

The colour of the spirit specimen is dark brown on the bivium, and lighter brown
on the trivium. The body (Plate I., fig. 6) is widest at the middle, and at the
anterior end tapers into a cylindrical neck which is about one-third of the length of
the body. At the posterior end the body suddenly contracts and ends in a point at
the anus.

The New Zealand specimen ends in a " short pointed tail " at the posterior end.
There is no actual process or " tail " in the Ceylon specimen, but it is not inconceivable

190 CEYLON PEARL OYSTER REPORT.

that during life the animal may have had a short posterior projection which has
become retracted. The difference, however, between the British Museum specimen
and the Ceylon specimen is, Professor Herdman informs me, not now very marked in
this respect.

There are five series of pedicels ; each series consists of a double row on the
" neck," but on the wider portion of the body each series of the trivium consists of
about four rows, while each series of the bivium consists of two or three rows. At
the posterior end the series are not so well defined, each having only one or two
rows of pedicels. There are also one or two pedicels on the interambulacra.

The sucking discs of the pedicels are dark brown or almost black in colour, thus
being easily distinguished on the lighter skin.

There are no anal teeth. The tentacles have been cast off.

Deposits: — The spicides (Plate I., figs. 2 to 4) are of one kind and are numerous.
Typically they are like a cross having four arms in one plane and with two additional
arms arising at right angles to this plane at the junction of the four arms. There
are many variations of this, some appearing like a short rod covered with many spines.

The calcareous ring (Plate I., fig. 5) is 5 millims long and consists of ten pieces.
The inter-radials are small and are separate from the radials. The radials are
bifurcated posteriorly, and the bifurcations are composed of several small pieces.

There is one stone canal and one Polian vesicle.

The retractor muscles are remarkably long, and are attached to the longitudinal
muscles halfway down the body.

Distribution : — New Zealand, Ceylon. Now recorded from the Indian Ocean for
the first time.

Cucumaria irabricata (Semper).

Ocnus imbricatus, Semper (2), 1868. Ocnus javanicus, Sluiter, 1880. Ocnus typicus,
Theel (7), 1886.

Ten specimens from (1) Pearl Banks (Stn. LXVL), Gulf of Manaar, (2) West of
Kaltura (Stn. XLI1L), 22 fathoms, and (3) Back Bay, Trincomalee (Stns. XX. and
XXI.). Lengths varying from 20 millims. to 50 millims.

Although Theel in his " Challenger" report retained the genus Ocnus, he
expressed some doubts as to its validity. Ludwig believed that the three forms
0. imbricatus, 0. javanicus, and 0. typicus were identical, and in his Holothurians
of Bronn's " Klassen und Ordnungen des Thierreichs" he placed them all in the
genus Cucumaria, under the name C. imbricata.

Eight of the Ceylon specimens I identified as Theel's species 0. typicus, and the
other twro I considered at first to be Sluiter 's species O. javanicus. But except for
some slight differences in the calcareous ring, in the arrangement of the pedicels, and
in the scales and colour of the bodv, the two forms appear \r> be very similar. So, on
the whole, I now think it best to unite them.

HOLOTHURIOIDEA. 191

The number of the pedicels on each of the five rows shows some variation, one
specimen only having from eight to ten pedicels in each row, whilst those of the
0. javanicus type have as many as from twenty to twenty-three. The average
number, however, in each row is about eighteen. In one specimen the rows of
pedicels showed a somewhat irregular arrangement. In the anterior half of the body
all of the five rows are in a straight line. At the middle of the body, however, each
of the rows makes a deviation and then continues to the posterior end of the body in
a straight line. So that the five rows in the posterior half alternate with the five
rows in the anterior half of the body.

Another specimen which is very much flattened dorso-ventrally is remarkable in
having the pedicels arranged in distinct rows only on the trivium. At a rough
glance the bivium appears to be altogether devoid of pedicels, and it is only on a very
close examination that a few very small and irregularly scattered pedicels can be
distinguished.

The character of the scales is not similar in all the specimens.

It happens that all the individuals which I had identified as 0. typicus are
yellowish-white, in alcohol ; and the two others (the 0. javanicus form) were of a
dark brown colour.

The deposits in all the specimens are very similar, and agree with the description
of 0. typicus given by Theel.

Distribution : — Hong-Kong, Bay of Bengal, Java, Ceylon.

Cuciunaria conjungens (Semper) (2).

One specimen from Pearl Banks, Gulf of Manaar. Length, 14 millims.

The specimen agrees very closely with Semper' s description, both in the nature of
the deposits and the calcareous ring.

Owing to the small size of the specimen, the arrangement of the dorsal pedicels
into three rows, as described by Semper, is not very clearly marked. The pedicels on
the ventral surface are much more numerous than the dorsal pedicels and are
irregularly scattered.

The body tapers at both ends, being more pointed at the posterior end.

This is recorded from Ceylon for the first time.

Distribution : — Bay of Manilla, Ceylon.

Thyone fusus (Muller), var. papuensis, Theel (7) — Plate I, figs. 7, S.

Two specimens from the Gulf of Manaar (Stn. IV.), 6-9 fathoms.

Lengths, 25 millims. and 22 millims.

The body is pointed at both ends. The pedicels are scattered all over the body,
but show an arrangement into longitudinal series not only on the ambulacra hut
also on the interambulacra. Tin's arrangement is somewhat obscure in some parts of
the body.

192 CEYLON PEARL OYSTEE REPORT.

The calcareous ring is, comparatively, of very large size, being 1 1 millims. long in
the smaller specimen. The posterior prolongations are composed of several smaller
pieces.

The deposits consist of tables which are very thinly scattered. They have four
large central holes and also four smaller peripheral holes. In the larger of the two
specimens the tables are imperfect, the circumference being broken at several places
(Plate I., fig. 8). Whatever may have been the cause of this breaking up, there is
no doubt they were originally similar to those of the smaller specimen (fig. 7), which
agree with Theel's figure.

There is no doubt that these specimens agree more closely with Theel's variety,
papuensis, than with the species. Thyonc fusus is a northern form, and Theel's
variety was obtained by the " Challenger " Expedition in Torres Straits. It is now
recorded from Ceylon for the first time.

Thyone sacellus (Selenka) — Plate I., figs. 9, 10.

Stolus sacella, Sel. (1), 1867. Thyone rigida, Semper (2), 1868. Stereodenna Murrayi,
Bell (4), 1883.

Two specimens from five miles off Negombo (Stn. I.), 12-20 fathoms, January 31,
1902. Lengths, 75 millims. and 50 millims.

Colour in spirit — -light yellow with irregular brown spots.

The skin is hard and rigid. The tentacles are retracted.

The pedicels are irregularly scattered over the body. They are very small and
numerous, showing an arrangement in three double rows on the trivium. These rows
are not continued to the extremities, but are confined to the middle of the body.

The calcareous ring is typical of the species.

Deposits : — These consist of four-holed plates having on each side a half ring
arising from the centre of the plate at right angles (fig. 9). In addition to these I
find numerous plates having more than four holes and having short spines on the
surface (fig. 10).

These specimens are evidently the same as Bell's Stereoderma murrayi, which is
now included in Selenka's species, Thyone sacellus.

Distribution : — Kurachee, East Coast of Africa, Torres Straits, Japan, and Ceylon.

Thyone (?) fusca, n. sp. — Plate I., figs. 11-13.

One specimen from Back Bay, Trincomalee (Stn. XXI.), 8-12 fathoms; 18 millims.
long and 1 0 millims. broad.

The colour of the spirit specimen is brown. The pedicels are the same colour as
the general integument.

There are no tentacles present in the preserved specimen.

The pedicels are irregularly scattered all over the body, being slightly more
crowded on the ventral surface than on the dorsal. There are no papillae present.

H0L0THUR10Il)EA. 1«)3

Tlie calcareous ring is small, being only 4 millinis. long. It is composed of ten
separate pieces. The radials are notched anteriorly and bifurcated posteriorly. Each
posterior prolongation is composed of about four small pieces. The inter-radials are
simple (tig. 11).

There is one stone canal and one Polian vesicle. There are no gonads present in
this specimen and the alimentary canal is eviscerated. Both the right and the left
branches of the respiratory tree are well developed. There are no anal teeth.

Deposits : — These are very scarce, and imperfectly formed. This leads me to
believe that the animal may have been preserved originally in formol, but I have no
record of this. The deposits are small plates having many holes, and probably
slightly hollow (tigs. 12 and 13). These are very rare. The pedicels have well-
developed terminal plates.

Owing to the tentacles being absent, I am unable to assign the specimen to its
genus with certainty, although it is, in all probability, a T/iyone.

Thyone (?) hornelli, n. sp.— Plate I, tigs. 14-10.

One specimen from the lagoon inside the Reef, Galle.

Length, 50 millims. ; breadth, 20 millims.

It is broader at the anterior end, and is slightly narrower at the posterior end.

The colour of the formol specimen is light brown, spotted irregularly with small
black marks. The sucking discs of the pedicels in some parts of the body are of a
rusty-red colour, and in other parts they are the same colour as the general
integument. Beneath the brown epidermis the skin is of a very light violet hue.

The pedicels, which are large, numerous and well formed, are irregularly distributed
over the body, showing no arrangement into rows. There are no papillae.

The tentacles are absent, and there are no anal teeth.

The calcareous ring is composed of five radial pieces and five inter-radials, which
are, however, not clearly separated from one another. The radials are notched
anteriorly and are bifurcated posteriorly, the posterior prolongations being composed
of several smaller pieces. The calcareous ring is fairly massive, being 15 millims.
long (fig. 14). There is one Polian vesicle and one stone canal.

The gonads are attached to the dorsal mesentery in one bunch.

The right and left branches of the respiratory tree are large, and both extend to
the anterior end of the body.

The internal organs and mesenteries are coloured a light violet, like the skin.

The longitudinal muscle bands are very well developed.

Deposits : — The spicules are very thinly scattered, and consist of small perforated
plates having a spiny surface (figs. 15 and 16). Since the animal has been preserved
in formol, it is doubtful whether this was originally the exact shape of the deposits.

T cannot be quite certain as to the genus of this form since the tentacles are not
present, but it is probably a Thyone.

2 C

194 CEYLON PEARL OYSTER REPORT.

Thyone (?) calcarea, a. sp. — Plate L, figs. 17-20.

One specimen from Cod Bay, Trincomalee (Stn. XXVII.), 6 fathoms.

Length, 20 millims.

The colour in spirit is yellowish-white.

The tentacles are not present.

The pedicels are small and numerous, and are the same colour as the skin. They
are scattered all over the body, and are more numerous on the ventral surface than
the dorsal. They form a double row on the five ambulacra, but only at the central
portion of the body. Those on the three rows of the trivium are longer and more
distinct than those of the two rows of the bivium.

There are five small calcareous teeth. The integument is thin but fairly hard.

The animal has a remarkably large calcareous ring, which is half the length of the
body. It consists of ten pieces, the five radials having posterior bifurcations which
are made up of a number of small pieces. Both radials and inter-radials are notched
anteriorly. The inter-radial pieces of the ring are not all of the same length (fig. 17).

There is one Polian vesicle, 4 millims. long, and one madreporite. The gonads are
attached to the dorsal mesentery. The alimentary canal is much convoluted.

Deposits : — The spicules are numerous and overlapping. They consist of tables
only. These are irregular in shape, mostly triangular or polygonal, and have from
five to a dozen holes. The spire consists of two upright rods which join at the top
and terminate in one or two blunt points (figs. 18-20).

As in the two previous species, the genus of this form, although probably Thyone,
cannot be decided with certainty because of the absence of the tentacles.

Phyllophorus cebuensis (Semper) — Plate II., figs. 22-24.
Thyonidium cebuense, Semper (2), 1868. See also Theel (7).

One specimen from Gulf of Manaar (Stn. II.), 8-9 fathoms (see Note, p. 205).

Length, 22 millims., and breadth, 13 millims.

Colour in spirit : — Brown epidermis covering a white skin.

The mouth is slightly dorsal, so that the trivium is a little longer than the bivium.

In the middle of the body the pedicels are irregularly scattered, being more
numerous on the trivium than on the bivium. At each end of the body, however,
the pedicels are arranged in five double rows.

There are five small anal teeth.

The calcareous ring agrees with Semper'*? description. Each of the radials has
four anterior processes, and also two posterior prolongations, each of which is made
up of four small pieces. The inter-radials are simple (fig. 24).

Deposits : — -Numerous tables of one kind only. Each table has a central hole
surrounded by about eight slightly smaller holes. The spire is tall and massive, and
consists of four upright rods, the adjacent ones being connected by four or five bars.

HOLOTHURIOIDEA. 1!)5

Tlie top of the spire is hemispherical and is covered by numerous spines (tin's. 22
and 23).

The Ceylon specimen agrees very closely with Semper's description. Unfortu-
nately that author does not give any satisfactory account or figures of the spicules.
Theel found amongst the "Challenger" Holothurians one which he believed to lie
identical with Semper's species. The deposits in the " Challenger " specimen were
of two* kinds and differed considerably from those of the Ceylon specimen (see
Theel (7)). Seeing that there is this difference in the deposits, the "Challenger"
specimen and the Ceylon specimen cannot be identical. And yet the Ceylon specimen
agrees very closely with Sempek's original description. On the other hand, Theel
expresses some doubt as to the identity of the " Challenger" specimen with Semper s
species. Consequently I feel justified in assigning the Ceylon specimen to Semper's
species; and I suggest that the " Challenger" specimen be placed as a variety of the
species, which might be named var. theeli.

Distribution : — Philippines, Ceylon.

Actinocucumis donnani, n. sp. — Plate II.; tigs. 25-30.

One specimen, from deep water off Galle (Stn. XL1.).

It is 15 millims. long, and 9 millims. broad at the widest portion of the body.

The colour of the spirit specimen is white.

The body is in a contracted condition, so that the exact arrangement of the
pedicels is not very easy to determine. There appear to be, however, five series of
pedicels, each series consisting of four or five fairly straight rows. The dorsal rows
are more irregular than the ventral ones. Owing to the width of each of the five
series, the interambulacral spaces are very narrow. The pedicels have well-developed
sucking discs, and in the preserved specimen are very short and distinctly cylindrical.
Amongst the pedicels of both the dorsal and ventral surface there are scattered a few
papilla?, which are easily distinguished from the pedicels, because of their greater
length, their shape, and their delicate appearance.

There are no anal teeth.

Deposits : — These are very thinly scattered, and consist of small oval perforated
plates (tigs. 26-28). In the pedicels there are numerous small slightly branched
bodies similar to those described by Theel as " incomplete rosettes" (figs. 21) and 30).
The pedicels have well-developed terminal plates.

The calcareous ring is comparatively large, being 8 millims. long. Each of the five
radials is composed of two separate pieces, both of which are prolonged posteiiorlv.
The inter-radials are five in number. They do not extend so far anteriorly as the
radials, neither have they any posterior prolongations. The radials and inter-radials
are made up of a number of small pieces (fig. 25).

* Semi>kr's species evidently had only one kind of tabic.
2 C 2

196 CEYLON PEARL OYSTER REPORT.

There is one large Polian vesicle, 4 millims. lons>', and a single stone canal.

The gonads are present only on the right side of the dorsal mesentery.

Although the tentacles are not present, I have decided to place this specimen in
the genus Actinocucumis, hecause of the arrangement of the pedicels, and also
because of the presence of papillae.

Colochirus quadrangularis, Lesson.

Colochirus cceruleus, Semper (2), 1868. See also Thef.l (7).

Four specimens from South of Adam's Bridge (Stn. LIV.).

Lengths, 75 millims., 60 millims., 30 millims., and 40 millims.

These specimens agree well with Theel's description.

Colour in spirit : — Yellow and dark brown, with a very faint tinge of violet.

Distribution : — Philippines, E. Africa, Australia, E. Indies, Ceylon.

Colochirus quadrangularis, var. mollis, nov. — Plate IT., fig. 21.

One specimen from South of Thanni-Kodi, Adam's Bridge (Stn. LIV.), 8 J fathoms.

Length 100 millims.

This differs from Colochirus quadrangularis in the texture of the body wall.
Instead of being very hard, thick, and rough, as in Col. quadrangularis, the skin is
soft, thin, and comparatively smooth.

Although this specimen is larger than any of those of Col. quadrangularis in
the collection, yet the papillae at the four angles of the body are much smaller
comparatively.

The colour of the animal also differs from that of the Ceylon specimens of Col-
quadrangularis. The following is the account of the colour of the living animal, as
noted by Professor Herdman : —

"Colour of body a uniform orange, slightly mottled with a paler tint. The crown
of tentacles are mottled yellow on a dark brown ground. The region between the
five valves at the base of the tentacles is white." Plate II., fig. 21, is from a drawing
in Professor Herdman's notes showing the living animal with tentacles expanded.

I think it advisable to call this specimen a new variety of Col. quadrangularis,
with which it agrees in other characters.

Colochirus doliolum (Pallas).

Actinia doliolum, Pallas, 1766. Colochirus australis, Lumvio (9), 1875. Also Theel (7).

Two specimens from South of Adam's Bridge (Stn. LIV.).
Lengths, 20 millims. and 8 millims.

The larger of these specimens agrees very closely with the descriptions of this
species, both in the form of the body and also in the nature of the deposits.

HOLOTHURTOTPEA. 197

The smaller specimen is evidently of the same species, although its small size and
its contracted condition prevent me from verifying all the characters in detail.
This species is new to the Ceylon fauna.
Distribution : — Australia, Ceylon.

Colochirus, sp. (?).

Navakaddua Paar (Stn. LXVIIL), 8-181 fathoms.

This specimen, which is only 7 minims, long, is too small to identify with any
certainty. The general external form of the body, together with the nature of the
deposits, leads to the conclusion that it is a Colochirus.

The body is quadrangular, having the pedicels on the trivium arranged in three
double rows. The body tapers at the posterior end.

Deposits : — These consist of reticulate cups, knobbed buttons, and very large
perforated plates.

The specimen is evidently young, but does not obviously fall into any of the other
species. It is perhaps nearest to C. doliolum, but diffei's in the tapering posterior
extremity.

Havelockia herdmani, n. gen. et sp.— Plate II., figs. 31-35.

One specimen from South of Adam's Bridge (Stn. LIV.), 4-40 fathoms.

Length 45 millims. and greatest breadth 17 millims.

The colour of the spirit specimen is brown with a dark streak of violet along the
middle of each side.

The body is indistinctly quadrangular, but pentagonal at each end. The mouth is
surrounded by five valves and there are five smaller valves around the anus.

The ambulacral appendages consist of pedicels and papillae. The pedicels are
confined to the ventral surface. They are arranged in three series traversing the
entire length of the ventral surface from the mouth to the anus. The central series
consists of about eight rows of pedicels, and the other two series are not quite so
broad. There are also a few scattered pedicels on the ventral interambulacra. The
papillae are absent on the ventral surface, but are scattered irregularly over the
remaining three sides, being most thinly scattered along the middle of the sides
(fig. 31). The anus is devoid of calcareous teeth.

The tentacles are not present. They have evidently been thrown off.

Deposits : — These consist entirely of numerous tables, which are of two kinds : —

(1) Those scattered throughout the skin generally. — These are small tables,
generally having four large holes and four smaller peripheral holes (fig. 32).
The number of the holes, however, varies. The spire is made up of two rods
which unite at the top and give off generally four short projections (fig. 331

198 CEYLON PEARL OYSTER REPORT.

(2) Tables in the papillae. — These are much larger than those of the general
integument, and are not regular in shape (fig. 34). They have a similar spire
to the smaller tables.

The calcareous ring is not very large, being 8 millims. long and 8 millims. broad.
It consists of ten pieces. The five radials are slightly notched anteriorly and are
bifurcated posteriorly. The posterior prolongations are composed of a number of
smaller pieces. The five inter-radials have no posterior prolongations and are pointed
anteriorly. Retractor muscles are present (fig. 35).

There is one Polian vesicle, and no stone canal can be seen. The gonads are
present in two bunches — one on each side of the dorsal mesentery. The right
respiratory tree is larger than the left. There are no Cuvierian organs.

The presence of posterior prolongations to the calcareous ring, together with the
possession of retractors, prove that this form is a Dendrochirote, although the
tentacles are absent.

It possesses a certain external resemblance to the genus Colochirus in the general
shape of the body ; in the arrangement of the pedicels in three rows on the ventral
surface, and of the papilla? on the dorsal surface ; and also in the presence of the five
valves around the mouth.

But there is no doubt that the species is not a Colochir us, because :—

(1) The pedicels extend the entire length of the ventral sui'face (in Cohchirus they

are absent at both ends).

(2) The deposits, which consist entirely of tables, are different from those of the

genus Colochirus.

(3) The calcareous ring has posterior prolongations.

Neither does this species agree with any other genus of the Dendrochirotie, so
that I feel compelled to form for it a new genus which may be defined as follows : —

Havelockia,* n. gen.

The body is indistinctly quadrangular, and the mouth and anus are each surrounded
by five valves. The ambulacral appendages consist of (l) pedicels, arranged in three
series on the ventral surface, each series extending from the mouth to the anus, and
consisting of several rows of pedicels ; (2) papillae, which are scattered irregularly
over the bivium.

The deposits consist entirely of tables. Each table has a spire consisting of two
rods, which are surmounted by three or four short blunt projections.

The calcareous ring has posterior radial bifurcations.

* Named after the SS. " Lady Havelock," from which Professor Hekdman worked during the greater
part of his expedition in the seas round Ceylon,

HOLOTHUEIOIDEA. 1'J'J

Family : ASPIUUCHIKUT.K.
Actinopyga mauritiana (Quoy and Gaimard).

Holothuria mauritiana, Q. & Gr., 1833. Miilleria varians, Selenka, 1S67. Miilleria
mauritiana. Semper, 1868. See also Theel (7).

One specimen from the lagoon inside the Reef, Galle. Length, 140 millims.

The specimen possesses most of the characters of the species. There are, however,
no white rings around the dorsal papillae.

On the ventral surface there is a well-marked white symmetrical patch which is
quite distinct from the brown dorsal surface.

In Theel's description this marked difference in colouring is not emphasised, and
he leads one to believe that the brown on the dorsal surface is gradually changed for
the lighter colour of the ventral surface. It is interesting to note that the specimens
of this species, which Professor Herdman kindly examined for me, with Professor
Jeffrey Bell, in the British Museum, showed transitions between those described
by Theel and the striking condition seen in the Ceylon specimen. So that it is
evident that the nature of the colouring of the ventral surface, with relation to its
distinctness from that of the dorsal surface, is susceptible of considerable variation in
the species.

The pedicels of the ventral surface are capable of great extension, and have white
sucking discs. The white integument of the ventral surface is closely covered with
small but conspicuous pores, suggesting the singular appearance of a white colony oi
the Compound Ascidian Leptoclinum.

Distribution :— Indian Ocean from E. Africa to East Indies ; Funafuti, in the
central Pacific.

Actinopyga serratidens, n. sp. — Plate III., figs. oG-41.

One specimen from the lagoon inside the Reef, Galle. Length, 180 millims.

Colour of spirit specimen is brownish -black.

The tentacles are partly retracted, so that it is difficult to ascertain their exact
number. There are, however, 20 tentacular ampullae, so that there will also be
20 tentacles. The colour of the tentacles is dark brown.

The mouth is ventral, and is surrounded by a distinct brim formed by a folding of
the integument. The anus is surrounded by live distinctly serrated teeth, each tooth
being 3 millims. in length.

The pedicels are irregularly scattered over the ventral surface, showing no
arrangement in rows. They are distinctly cylindrical with well-developed sucking
discs. The dorsal surface is covered with papillae, which are more slender than the

200 CEYLON PEARL OYSTER REPORT.

pedicels. They appear, in many cases, to have small rudimentary terminal discs, so
that it is difficult to distinguish them from true pedicels. Both pedicels and papillae
are of the same colour as the general integument, so that they are not very
conspicuous.

The specimen has a typical Aspidochirote calcareous ring.

There is one large Polian vesicle, 30 millims. long, and there are about eight stone
canals attached to the dorsal mesentery.

The right respiratory tree is much larger than the left. This form also possesses
Cuvierian organs.

The general body wall is very thick, about 5 millims. This is probably, to a certain
extent, due to contraction.

Deposits : — Not very thickly scattered. They consist typically of a short straight
rod with dichotomising ends (figs. 36-38). Sometimes the spicules are dumb-
bell shaped or bone-shaped (figs. 39-41). The pedicels have no supporting rods, nor
spicules of any kind, except a terminal plate. The character from which I have taken
the specific name, viz., the serration of the anal teeth, is a very distinct one, and
would serve alone to distinguish the species.

Holothuria kurti, Ludwig. — Plate III ' figs. 42—45.

&■-

H. lamperti, Sluiter, 1889 (10), (15).

One specimen from Pearl Banks, Gulf of Manaar (Stn. LXVi.) ; three specimens
from south of Adam's Bridge (Stn LTV.), 4 to 40 fathoms.

The lengths of the specimens vary from 25 millims. to 40 millims. The specimens
agree with Sluiter's description.

Deposits : — The spicules agree in the main with Slujter's description There are
two kinds of table — round tables and cross-shaped tables, each kind being surmounted
by a comparatively tall tower ending in numerous teeth. The size of the tables
varies very much. In the papillae there are also knobbed " buttons," having six or
seven pairs of holes as figured by Sluiter. In some of the specimens there are also
some smooth buttons scattered about in the skin, having six or seven pairs of holes.

So far as I can determine, the cross-shaped tables are derived from the round tables
by pieces having become broken or dissolved away ; so that there is really only
originally the one kind of table, the cross-shaped form being only a stage in the
dissolution of the round form. I found all stages between the two extremes (see
tigs. 42-45). Consequently, in a young specimen, we should expect the round form
to predominate, and as the animal grows bigger, the cross-shaped form of table would
increase in number.

This species is now recorded from Ceylon lor the first time.

Distribution : — Java, Ceylon.

IIOLOTHUKIOIDEA. 201

Holothuria inonacaria (Lesson).

Psohis monacaria, Lesson, 1830. See also Theel (7).

One specimen from Aripu reef (March 18th); and one specimen from northern part
of Gulf of Manaar (Stn. LIV.), 4 to 40 fathoms.

Lengths, 75 millims. and 38 millims.

The colour in alcohol is brown, with yellow rings around the papillae. The pedicels
are light brown. The tentacles are yellow.

There are papillae on the dorsal surface, and pedicels on the ventral surface. At
the anterior third of the body the papillae are arranged in five distinct longitudinal
vows. In the posterior two-thirds they are more irregular. The pedicels are also
arranged in five more or less irregular rows on the anterior third of the ventral
surface, and they are more irregularly scattered over the remaining two-thirds.

The mouth is surrounded by a crown of small papillae.

Deposits : — These agree with those figured by Theel. Although the Ceylon
specimens differ in the arrangement of the pedicels and papillae from Theel's
description of H. monacaria, yet I think there is no doubt as to their identity with
that species.

Distribution : — Indian Ocean, E. Indies, Australia, Pacific Islands.

Holothuria vagabunda, Selenka.

Stichopus (sub-genus Gymnochirota) leucospilota, Brandt, 1835. See also Selenka (1),
Semper (2), Theel (7).

One specimen from the lagoon inside the Reef Galle. Length, 180 millims.

This specimen agrees with the descriptions of the species.

Distribution : — E. Africa, Indian Ocean, E. Indies, Hong Kong, Pacific Islands.

Holothuria tenuissima, Semper (2). See also Theel (7).

Two specimens from the lagoon inside the Reef, Galle ; one specimen from off
Negombo (Stn. I.). Also elsewhere in Gulf of Manaar (Stn. IX.), 7 fathoms.

Lengths of two specimens, which were in a very contracted condition, 130 millims.
Length of other sjaecimen, 80 millims.

The specimens agree with the descriptions of the species.

The pedicels, which are scattered irregularly all over the. body, are more numerous
on the ventral surface. The anus is slightly pentagonal, with a group of papillae at
each angle.

The smallest of the specimens is evidently a young form, but it agrees with the
larger specimens in most respects. Its body wall is very thin, doubtless owing to its
immature condition. There is also a small circular area around the mouth — about
1 5 millims. in diameter — where the skin is much thinner and devoid of pedicels.

2 D

202 CEYLON PEAEL OYSTER REPORT.

These specimens also agree with the descriptions of H. vitiensis, H. kcellikeri, and
II. clemens, and it is very probable, as Theet, suggests, that they all belong to one
and the same species, which is susceptible of great variation.

Distribution : — Indo-Pacific region.

Holothuria marmorata (Jager).

Boliadschia marmorata, Jager, 1833. See also Theel (7).

One specimen from the lagoon inside the Reef, Galle. The species was also,
Professor Herdman's notes show, found at Trincomalee. Length, 240 millims.

Colour in alcohol. — The ventral surface is a dark brown with a violet tinge. The
dorsal surface is lighter, especially at the posterior end. The colour on the dorsal
surface is not uniform, but there is not the striped appearance that is typical of the
species.

The pedicels are scattered all over the body, the skin being considerably darker at
the base of each pedicel.

The anus is pentagonal and is surrounded by five groups of papilla?, each group
consisting of five papillae.

The deposits are typical.

This specimen is very similar in most respects to II. tenuissima. It differs slightly
from the latter in the nature of the deposits, the spicules not dichotomising to such
an extent but having rather the appearance of perforated granules. The papillae
around the anus also are more prominent than in H. tenuissima. Nevertheless, in
spite of these differences, it is highly probable, as Thkel suggests, that II. marmorata,
II. tenuissima, together with other allied forms are only, at the most, varieties of the
one species.

Distribution : — Indo-Pacific region generally.

Holothuria atra, Jager.

H. (subgenus Microthele) affinis, Brandt, 1835. See also Theel (7).

There are seven specimens, most of them being very much contracted. This
species was found at various localities round Ceylon — in the Gulf of Manaar, at
Trincomalee, and at Galle.

The colour in alcohol is dark brown on the dorsal surface and lighter on the ventral.
Professor Herdman's notes state that at least some of the specimens when alive were
quite black above, but of a pink colour below.

The dorsal papillae are smaller than the ventral pedicels.

The deposits are typical. The discs of the tables are smooth and have no
peripl i eral perforations.

The gonads are absent in all specimens. Cuvierian organs also are not present in

HOLOTHURTOTPEA.

203

any of the specimens, so that it is highly probable that this species dot's not possess
Cuvierian organs.

In all the specimens the sjiicnles are similar in density and form.

Although the tentacles are retracted in most of the specimens, there appear to be
20 tentacular ampullae in each specimen.

In every specimen the left respiratory tree is much larger than the right, the
former extending to the extreme anterior end of the body.

Appended is a table showing some of the variations noticed in the seven specimens
examined : —

Locality.

Length.

Greatest
breadth.

Polian vesicles.

Stone
canals.

Longest
tentacular
ampullae.

Number.

Greatest
length.

Pearl Banks, oft" Aripu

Trincomalee

OfT Periya Paar ....

Eeef Galle

Off Galle

G. of Manaar

S.W. Cheval Paar . . .

millims.
125
155
185
155
105
75
135

millims.

23
38
34
34

28
30
35

4

1

5

2

1

1

millims.

22

14
12

18

15

9

19
17
11
12
9
27
13

millims.
25

15
15
14
10

7
14

Holothuria gallensis, n. sp. — Plate III., figs. 46-50.

Three specimens from the lagoon inside the Reef, Galle.*

Lengths, 230 millims., 150 millims., and 70 millims.

The tentacles are not present in any of the specimens ; but there are 20 tentacular
ampullae, so that although the tentacles themselves are absent, we may safely conclude
that the animal had 20 tentacles.

The body is divided into a distinct dorsal and ventral surface. The dorsal surface
is black and is crossed by numerous conspicuous transverse yellow streaks (Plate III.,
fig. 4G). The pattern, however, varies somewhat in different specimens, the yellow
streaks in the smallest not being very evident. On the ventral surface the colour is
light yellow, mottled all over with small dark grey patches.

Amtmlacral appendages : — On the dorsal surface there are small papilla?, which are
very thinly scattered and inconspicuous. The appendages on the ventral surface are
much more numerous, and are easily distinguished because each one is generally
situated in the centre of a dark grey patch. These appendages, which are mostly
retracted, are evidently true pedicels. They have only a small terminal plate, and
they are strengthened by spicules similar to those found in the general integument.

* This species was, evidently, from Professor Hehdman's notes, also found in China Pay, Trincomalee.

2 D 2

204 CEYLON PEARL OYSTEE REPORT.

The mouth is ventral, and is surrounded hy a small brim of papillae. There are no
anal teeth.

Deposits consist of two kinds : —

(1.) Closely packed tables having, in the older specimens, a large central hole and
about eight smaller peripheral holes. This is surmounted by a spire having
four upright bars. There is one tier of horizontal bars. The spire terminates
in a round top having numerous spines (figs. 47 and 49).

(2.) Knobbed "buttons," having generally three pairs of holes (fig. 48).

The tables in the smallest specimen are much better developed than in the older
specimens. The buttons in the youngest animal have about five pairs of holes, whilst
those in the older specimens invariably have only three (see figs. 49 and 50). These
facts incidentally bear out Mitsukuri's (14) statement with regard to the changes in
growth of spicules.

The calcareous ring is simple, like that of a typical Aspidochirote.

There are two long Polian vesicles in the specimen dissected. No stone canals are
seen.

It is noteworthy that although this species has never been previously described, it
is evidently a fairly common form on the Ceylon coast. It is one of the species used
as " Trepang," and has apparently not been distinguished from some of the other
large species of Holothuria. Possibly, on account of its mottled appearance, it has
been confused with H. marmorata, from which, however, it differs in many respects.
The yellow transverse stripes (see Plate III., fig. 46) on the dorsal surface and the
mottling ou the ventral are very characteristic.

Stichopus cliloronotus, Brandt.

St. cylindricus, Haacke, 1880. See also Thkel (7).

One specimen from East Cheval paar, 5^ fathoms. Length, 140 millims.

This specimen agrees very closely with Theel's description. There are, however,
only 19 tentacles in the Ceylon specimen.

There are four longitudinal series of protuberances on the dorsum, the two dorsal
series being double, while the two ventral series have a more or less zig-zag
arrangement.

The pedicels are irregularly distributed over the ventral surface. Professor
LTerdman's notes state that the body was of a dark green colour when alive.

Distribution : — Pacific Islands, Indian Ocean from E. Africa to Malay Peninsula.

Stichopus chloronotus, var. fuscus, nov.

Three specimens from Pearl Banks, Gulf of Manaar (Stn. LVIIL), 9-2G fathoms.
Lengths, 170 millims., 200 millims., and 110 millims.

HOLOTHURIOIDEA. 205

The mouth is surrounded hy a crown of papillae.

The number of tentacles is different in each specimen. There are 1 8 in the largest,
14 in the next, and 16 in the smallest. In the two latter it is highly probable that
some tentacles are retracted.

There are four irregular rows of protuberances — one row along each side of the
body. In this it differs from Stichopus chloronotus, which has two double rows on
the dorsal surface. The pedicels are irregularly scattered on the ventral surface,
showing a slight indication of forming three rows.

The deposits agree with those of Stichopus chloronotus, except that the C-shaped
deposits are very rare indeed.

These two spirit specimens are very much darker in colour than the spirit specimen
of St. chloronotus, the former being a dark chocolate-brown.

I consider that the differences between these specimens and St. chloronotus justify
the formation of a new variety.

Stichopus variegatus, Semper.

St. naso, Haacke, 1880. See Semper (2), Theel (7).

Two specimens from S.W. of Periya Paar (Stn. LV.), 11-24 fathoms.

Lengths, 85 millims. and 75 millims.

The specimens are very much contracted and in a poor state of preservation.

The tentacles in one specimen are dark brown and in the other yellow. I am
unable to count them owing to their poor state of preservation, but in other respects
the specimens agree with Semper' s description.

The pedicels are arranged in three series on the ventral surface, each series having
about four rows.

Distribution : — Lido-Pacific, Mauritius, E. Indies, Ceylon.

Note. — While this Report was in the press another specimen (from Gulf of Manaar,
February, 1902) was found which is nearly related to Phyllophorus cebuensis,
but may be distinct, as it differs in the deposits, having additional rosette-
shaped buttons.

206 CEYLON PEARL OYSTER REPORT.

LITERATURE REFERRED TO.

(1.) Selenka.— « Zeit. £ wiss. Zool.,' XVIL, pp. 291-374, 1867.

(2.) Semper. — ' Reisen im Archipel der Philippinen,' 2. Th., 1. Band, 18G8.

(3.) Hutton.— ' Trans, and Proc. New Zealand Inst,,' 1878, vol. XL, pp. 305-308.

(4.) Bell.— 'Proc. Zool. Soc.,' 1883, Part I, pp. 58-62.

(5.) Bell.—' Zoological Collections of H.M.S. " Alert." '

(6.) Lampert. — ' Archipel der Philippinen. Die Seewalzen,' 1885.

(7.) Theel.—" Challenger," Holothnrioidea (Part II.), vol XIV., Part XXXIX.

(8.) Bell.— ' Sci. Trans. Roy. Dublin Soc.,' 1887, vol. III. (Series II.), pp. 643-657.

(9.) Ludwig.— ' S.-B. Akad. Berlin,' 1887 (pp. 1217-29).

(10.) Sluiter.—" Fauna des Java-Meeres " ; 'Nat. Tij. v. Ned. Indie,' XLVIL, 1887.

(11.) Sluiter.— ' Nat. Tij. v. Ned. Indie,' XLIX, An. 2, p. 106, 1889.

(12.) Ludwig. — ' Bronn's Klassen u. Ord. d. Thierreichs, Echinodermen,' 2. Band,
3. Abth., 1889-1892.

(13.) Ludwig.— ' Mem. Mus. Comp. Zool. Harvard,' vol. XVIL, 3, 1894.
(14.) Mitsukuri. — ' Annotationes Zool. Japonenses,' vol. 1, 1897, pp. 31-42.
(15.) Sluiter. — ' Die Holothurien der Siboga Expedition,' 1901.
(16.) Bell.— 'Ann. Mag. Nat. Hist.,' (5), vol. 19, 1887, p. 392.
(17.) Bell.— 'Ann. Mag. Nat. Hist.,' (5), vol. 20, 1887, p. 148.

(18.) Walter.—" Ceylon Echinodermen." ' Jenaische Zeitschrift,' XVIII.,
pp. 365-384, 1885.

(19.) Thurston. — 'Notes on the Pearl, &c, and Marine Fauna of the Gulf of
Manaar.' Government Central Museum, Madras, 1890.

IIOLOTHUKIOIDEA. 207

EXPLANATION OF PLATES.

List of Reference Letters.

a., anus ; ant., anterior end ; dors, p., dorsal papillae ; ?'., inter-radial ; m., mouth ; p.b., pedicels of the bivium ;
p.})., posterior prolongations of radials ; p.t., pedicels of the trivium; r., radial ; s., spire of table.

PLATE I.

Fig. 1. Tentacles of Synapta striata, Sluiter, from life.

Fig. 2-4. Spicules of Cucwmaria turbinata (Hutton).

Fig. 5. Calcareous ring of same.

Fig. 6. Side view of C. turbinata ; three times natural size.

Fig. 7. Top view of a complete table of Thyone fusus, var. papuensis, Theel.

Fig. 8. Top view of an incomplete table of same.

Fig. 9-10. Spicules of Thyone sacellus (Selenka).

Fig. 1 1 . Calcareous ring of Thyone (?) fusca, n. sp.

Fig. 12-13. Spicules of same.

Fig. 14. Calcareous ring of Thyone (?) hornelli, n. sp.

Fig. 15-16. Spicules of same.

Fig. 17. Calcareous ring of Thyone (?) calcqrea, n. sp.

Fig. 18-20. Spicules of same. (Fig. 19 is side view of table.)

PLATE II.

Fig. 21. Colochiins guadrangularis, var. mollis, nov. ; natural size, from life.

Fig. 22. Side view of spicule of Phyllophorus cebuense (Semper).

Fig. 23. Underneath view of same.

Fig. 24. Calcareous ring of Phyllophorus cebuense.

Fig. 25. Calcareous ring of Actinocucuniis donnani, n. sp.

Fig. 26-28. Spicules in general integument of same.

Fig. 29-30. Spicules of tube feet of same.

Fig. 31. Side view of Havelockia herdmani, n. gen. et sp. ; twice natural size.

Fig. 32. Top view of " table " in the general integument of same.

Fig. 33. Side view of " table " in the general integument of same.

Fig. 34. Top view of " table " of the papilla; of same.

Fig. 35. Calcareous ring of Havelockia herdmani.

208 CEYLON PEARL OYSTER RETORT.

PLATE III.

Fig. 36-38. Small dichotomising rods of Actinopyga serratidens, n. sp.

Fig. 39-41. Bone-shaped spicules of same.

Fig. 42-45. Showing transformation from a round " table " to a cross-shaped " table " in Holothuria

I.iati, Ludwig.
Fig. 46. Holothuria gallensis, n. sp., dorsal surface; natural size.
Fig. 47. Side view of " table" of Holothuria gallensis, n. sp.
Fig. 48. " Knobbed button " of same.

Fig. 49. Underneath view of " table " in older specimen of H. gallensis.
Fig. 50. View of " table " in younger specimen of H. gallensis.

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CEYI ON PI ARL OYSTER REPORT

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Figs 25

CEYLON PEARL OYSTER REPORT

HOLOTHURIOIDEA. PLATE III.

'

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42-45, HOLOTHURIA KURTI; FlGS. 46-50, HOLOTHURIA GALI

[CEYLON PEAEL OYSTER FISHERIES— 1903- SUPPLEMENTARY REPORTS, No. VI.]

REPORT

ON THK

CEPHALOCHORDA

COLLECTED BY

Professor HERDMAN, at CEYLON, in 1902.

BY

WALTER M. TATTERS ALL, B.Sc,

SCHOLAR IN ZOOLOGY OF VICTORIA UNIVERSITY.

[With ONE PLATE.]

INTRODUCTION.

The collection of Acraniates made by Professor Herdman during his recent expedition
to Ceylon was kindly placed in my hands for examination during my year of post-
graduate research work at University College, Liverpool. I here wish to express my
thanks to Professor Herdman for giving me the opportunity of examining this most
interesting series, and also for the ever-willing and kindly help which he has given
me in the discussion of literature and other difficulties. The collection was a most
interesting one, and comprised in all 98 specimens, 92 obtained by dredging and
6 taken in the surface tow-net. They were collected for the most part in the shallower
waters round Ceylon between February 1st and April 1st, 1902 ; and as the
specimens belong to no fewer than seven usually recognised species, they serve to
indicate the richness of the Acraniate fauna of the Ceylon seas.

The previous knowledge of the Cephalochorda of the Ceylon coast is very scanty.
Andrews (3),* in Appendix I. to his paper on Asymmetron, notes Branchiostonni
lanceolatum as doubtfully known to him from Ceylon. In Appendix II. to the same
paper, in which the Lancelets of the Smithsonian Museum are enumerated, bottle
34,003 is labelled — " Amphioxus sp. , 5 soft specimens from Ceylon." Miss Kirkaldy (6)
examined these specimens later and found that four belonged to a new species, which
she named A. cingcdense. The other one she placed provisionally and doubtfully in

* The numbers in brackets refer to the List of Literature cited on p. 226,

2 E

210 CEYLON PEARL OYSTER REPORT.

the species B. belcheri. Thus, at most, three species, represented by six specimens,
were then known from Ceylon ; and during the course of Miss Kirkaldy's work
she received four more specimens from Ceylon which proved to he A. cine/ale use.

The present collection, therefore, is by far the largest yet made known from Ceylon.
The species include — Branchiostoma lanceolatum, B. lanceolatum, var. belcheri,
Asymmetron (Heteropleuron) cingalense, Asymmetron (Heteropleuron) cultellum,
Branchiostoma (Dolichorhynchus) indicum, Branchiostoma pelagicum (the six tow-net
specimens), and B. californicnse (?).

The specimens were preserved, some in alcohol and others in formol, and the latter
were in a most excellent state of preservation, being rendered slightly transparent,
while the exact outlines and shapes of the fins were splendidly maintained. The
spirit specimens were not nearly so good, so far as regards the external appearance,
although better in some respects for histological examination.

The group Cephalochorda has a single family, Branchiostomatidae, containing two
genera, Branchiostoma and Asymmetron. In discussing the Ceylon species, I shall
follow the classification and nomenclature given in my recent paper published by the
Liverpool Biological Society (10).

Genus I. —BRANCHIOSTOMA, Costa.

Metapleural folds end symmetrically just behind the anus, separated by the ventral
fin ; gonads disposed in two lateral series ; ventral fin with fin chambers which
may or may not have fin rays ; oral cirri when present have sense-papillae ;
atrial chamber prolonged behind the atriopore in a single (right) caecum.

Branchiostoma lanceolatum (Pallas) — Plate I., figs. 1,2.

Limax lanceolatus, Pallas, 1776.
Branchiostoma lubricum, Costa, 1834 and 1813.
Amphioxus lanceolatus, Yakrell, 1836, and others.
Branchiostoma lanceolatum, Gray, 1851, and others.

This species, which has only before been doubtfully recorded from Ceylon
(Andrews (3)), was represented by ten specimens in the collection.
They were from the following localities : —

(1.) Galle (Stn. XXXV.), February 14th, 7 fathoms. Two specimens.

(2.) Ten miles North of Cheval Paar (Stn. LIIL), March 6th, 7h fathoms. Three

specimens.
(3.) Periya Paar Kerrai (Stn. LIU.), March 4th, 7^ fathoms. One specimen.
(4.) Off Watering Point, GaUe (Stn. XXXVIIL), February 17th, 9 fathoms.

Four specimens.

The various measurements of these ten specimens will be found in Table I. at the

CEPHALOCHORDA. 211

end of the report. The greatest length recorded is 41 millims. and the least
26 millims., the average for the ten being 34-5 millims., considerably lower than
Kirkaldy's average figures (6).

Of the ten, four were males and two females, the males being of greater average
length, while the sex of the remaining four could not be determined. These latter
were those found oft' Watering Point, Galle, and one of them had a double row of
exceedingly minute gonads as if just developing, while the other three had none
whatever. This possibly gives us a clue to the spawning time of the species in
tropical seas. It will be noticed from Table I. (p. 222) that these four and the two
first males from Galle were caught at least a fortnight before the other specimens,
and their gonads were in various stages of development. Those caught 14 to 20
days later had larger and almost mature gonads, in spite of the fact that one at least
was considerably smaller than those caught at the earlier date. This would give us
the middle of March to the beginning of April as the probable spawning time of these
Ceylon specimens of B. lance olatum.

In those specimens in which gonads were present they formed a double series of
pouches, generally equal in number on the two sides. The average number present
was 23 on each side, rather below Kirkaldy's average (6). The Galle specimens,
preserved in formol, are of a pink tint and almost transparent ; the rest, which are in
spirit, vary in colour from fawn to a deep orange and are much more opaque.

The number of myotomes varied between 59-61, not a great range; but the
arrangement of the somites varied considerably, as Table I. shows. The preatrioporal
myotomes ranged from 35 to 37, the average being 36. This is rather more than
Kirkaldy's figures show, but Andrews (3) records several with 37 and one with 38
preatrioporal myotomes. The preanal myotomes varied between 11 and 14, the
average being 13. Nos. III. and V. on Table I. show only 11 preanal myotomes.
This is the lowest number recorded for the species, but repeated countings have
confirmed the figure. This is one more instance of the great variability in the
arrangement of the myotomes within a given total. The postanal myotomes vary
between 11 and 13, the usual figures for the species.

The fins of these specimens agree closely with Kirkaldy's figures, especially the
caudal fin (fig. l), which is remarkably constant throughout.

The ventral fin has a double series of fin rays, in fin chambers, extending its whole
length. The ventral fin chambers are prolonged postanally for a considerable length
(fig. 1), and in II., Table I., there certainly is a postanal extension of the fin rays — in
spite of Lankestee's and Benham's statements to the contrary. The fin rays appear
to be better developed both in the dorsal and ventral fins in the older specimens.

The relation ot the anterior ends of the notochord and dorsal fin is in all cases as
Kirkaluy figures it, i.e. the dorsal fin ends conterminously with the myotomes,
while the notochord is prolonged further forwards a little way. The nervous system,
however, does not always project beyond the dorsal fin, as in one or two of the

2 E 2

212 CEYLON PEARL OYSTER REPORT.

Ceylon specimens they ended together. The "Raderorgan" is well developed in
these specimens, and has a median dorsal lohe and five or six large lateral lohes on
each side. In one specimen examined one of the lateral lobes was branched.

No. IV., Table L, showed an unusual dark oval patch anterior to the dorsal fin
and just dorsal to the notochord (fig. 2). No structure could be made out, but when
cleared up in clove oil the dark patch was found to have a ventral extension on the
left side. Unfortunately the specimen had not been preserved specially for
histological work, and so the sections that were made showed no additional structure,
the only appearance being a large patch dorsally and to the left side of the notochord,
which stained deeply with hematoxylin.

Branchiostoma lanceolatum, var. belcheri, Gray. — Plate L, fig. 3.

Branchiostoma belcheri, Gray, 1847, and others.
Amphioxus belcheri, Kirkaldy.

This variety, which is usually regarded as a distinct species, formed the greater
part of the collection, being a total of 58 specimens out of 98. It has only been
previously recorded from the neighbourhood of Ceylon by Thurston* in 1890, who
mentions the species being dredged 30 miles south of Madras in 1887-88 ; in fact it
has been found but sparingly anywhere before. This large collection, therefore, has
offered opportunity for a closer examination of this form, which, I think, has shown
that we cannot any longer regard it as specifically distinct from B. lanceolatum.
This matter is dealt with in detail in my recent paper in the ' Transactions of the
Liverpool Biological Society,' where I have given tables compiled from the observations
of different workers, showing how the characters of the one form fade gradually into
those of the other.

The Ceylon specimens were found in the following localities : —

(1.) Ten miles north of Cheval Paar, June 3rd, 1902, 7| fathoms. Seven

specimens.
(2.) Outside Karativo Paar (Stn. LVIIL), March 10th, 10 fathoms. Two

specimens.
(3.) Oft* Karkopani (Stn. IV.), February 2nd, 8 fathoms. Two specimens.
(4.) Off Mutwal Island (Stn. LXVIL), March 19th, 14 fathoms. Three specimens.
(5.) Periya Paar Kerrai (Stn. L.), 7^ fathoms, sand, March 4th. Four specimens.
(6.) Off Chilaw Paar (Stn. LXIX.), 10 fathoms, March 20th. Six specimens.
(7.) West Cheval Paar (Stn. LXV), March 18th, 7\ fathoms. Nine specimens.
(8.) Near Periya Paar (Stn. LXIL), March 13th, in Foraininiferal sand,

11 fathoms. Eleven specimens.
(9.) South-west of Cheval Paar (Stn. XLIX.), March 1st, 8| fathoms. Fourteen

specimens.

* Madras Government Museum, Bulletin No. 1, p. 26.

CEPHALOCHORDA. 213

The colour of these specimens varied somewhat. Those found outside Karativo
Paar and off Mutwal Island were a deep orange colour ; those found near Periya Paar
and south-west of Cheval Paar were pure white, while those from west of Cheval
Paar, on March 18th, were of a purplish-pink colour.

The measurements of these specimens are recorded in Table II., pp. 223, 224.

In length they vary considerably, from 25 millims. to 56 millims., the average being
41*5 millims. One specimen, XXIV., Table II., was much damaged, all the postanal
and one half of the part between the anus and atriopore being missing. The remainder
measured, however, 53 millims., giving us 70 millims. as the probable length of the
whole animal — quite a giant amongst Acraniates.

Out of the 58 specimens, 28 were females, and only 10 were proved to be males ;
the sex of 20 could not be determined owing to the absence of gonads.

The size of the animal appears to bear a relation to the period of sexual maturity,
which is contrary to what Forster-Cooper (8) found for Asymmetron lucayanum.
Here it is the largest that have well-developed gonads and the smallest that are
immature. All the immature ones were under 36 millims. in length. This would show
that at a length of about 40 millims. the form B. belcheri becomes adult. All these
specimens, it may be noted, were caught at about the same time of the year and in
much the same locality, and there can be no question of some being taken at the
spawning season and others not. It must be that the larger ones only were adult
and the others immature. In the spirit specimens the gonads could not, in all
cases, be counted, owing to the opacity of the metapleural folds, but in the formol-
preserved specimens they were determined with ease.

In all the specimens counted, except one, the gonads of the right side were more
numerous than those of the left, the average being 25 right to 23 left. The lowest
number was 15 (some had evidently been already shed), and the highest was 30.

A few specimens had peculiar gonads. No. XX., Table II., had unusually small
gonads, though itself a large specimen ; while No. XXVI., Table II., showed a curious
arrangement, some of the gonads being quite small and alternating with large
mature ones. Late in March and early in April seems to be about the spawning
time of this variety in the Gulf of Manaar.

The variation in the myotomes is striking, not so much in the total number as in
the distribution. The total myotomes ranged from 63 to 66, 64 being the average.
The commonest formula was 38, 17, 9, which agrees closely wTith Kirkaldy's
figures (6), and differs considerably from Gunther's (1). The number of preatrioporal
myotomes varied from 36 to 39, by far the greater number, 34 out of 58, having 38.
The number of preanal myotomes varied from 16 to 18, 17 being the average; while
the postanal myotomes numbered 8 to 10, 9 being the commonest number.

From these figures it will be seen that B. belcheri from Ceylon agrees closely with
those from Australia examined by Kirkaldy (6), and the two are undoubtedly the
same species, and not distinct forms as Miss Kirkaldy suggested.

214 CEYLON PEARL OYSTER REPORT.

The fins of B. belchevi are fairly constant (fig. 3) and agree with Kirkaldy's
figure, except that she figures the rostral fin proportionately rather small. In ours
it is well developed, rather long, and more pointed than her figure shows. In
some specimens it is so well devekmed as to suggest a transition from B. lameolatus
to B. indicus. The ventral fin has fin chambers and a double series of ventral fin i"ays.

The extent of development of fin rays appears to vary with the age of the animal.

In the smallest specimens no ventral or dorsal fin rays are present. In those a
little larger, dorsal fin rays appear, the ventral ones being still undeveloped ; while
in those a little larger again, both series are seen.

The fin chambers are not prolonged postanally. The nervous system and the dorsal
fin end conterminously, while the notochord is prolonged a little way in front of both.

A faecal pellet adhering to the anus of No. LIII., Table II., on examination was
found to be rich in skeletons of diatoms, which gives an indication of the food.

The intertentacular membrane between the oral cirri of B. belch en is low, and the
sensory-papillae are very large and prominent.

The " Raderorgan " is exceptionally well developed, there being a large median
dorsal lobe and six lateral lobes on each side. The liver is exceptionally large and
extends for three-quarters of the length of the pharynx on the right side.

Branchiostoma pelagicum, Gunther (1889). — Plate I., fig. 16.

The six specimens taken in the tow-net were found to be poorly preserved, and
being also extremely small, their identification is a matter of some difficulty. I think,
however, that there can be little doubt that they are B. pelagicum, Gunther (2).

Of the six, one was taken in a coarse tow-net in the Indian Ocean, to the south-
east of Sokotra, about halfway between Perim and the Maldives, on January 16th,
1902 ; while the other five were taken with a fine net on January 20th, 1902, in the
Indian Ocean, after passing Minikoy Atoll, and therefore hetween the Maldives and
the Gulf of Manaar. There is therefore no doubt as to their all being truly pelagic
f< >rms.

The largest measured 8 '5 millims., the smallest 4 "5 millims., the average for the
six being 6 millims. The greatest breadth of the largest specimen was 1 millim.
All six are undoubtedly the same species, and agree in detail as far as can be made
out.

The notochord extends from the extreme tip of the snout to the end of the tail,
projecting some little way beyond the myotomes.

The nervous system stops short of the end of the notochord at both extremities.
The eye spot is very large and conspicuous, far larger in proportion to the size of
the animal than in the other species. This, in itself, is suggestive of a pelagic life.
All along the nerve cord, at regular intervals, occur groups of five or six large
pigment spots (fig. 16). This is a character noted in Gunther' s B. pelagicum.

The number of myotomes (as nearly as could be determined from the imperfect

CEPHALOCHORDA 2 1 5

preservation) was 65. Gunther's B. pelagicum had 67 ; while one specimen
described by Forster-Cooper (8) had 60. This specimen was 21 millims. long,
twice as long as Gunther's.

There was no trace of oral cirri to be seen, nor did Forster-Cooper find any in his
specimen (8). This then appears to be a true character of the species, and not to be
due to any imperfection in preservation. It is, moreover, what might be expected.
The oral cirri probably have, as one of their functions, to direct currents of water into
the oral hood and so to the mouth and alimentary canal. This is absolutely necessary
in an animal which leads a sedentary life. But a pelagic form, by virtue of its mode
of life and motion through the water, would cause currents in the right direction, and
thus the oral cirri would be rendered unnecessary.

No gonads could be observed in any of the six specimens. They were probably
immature. In none were the dorsal, ventral, or caudal fins preserved sufficiently well
to indicate, in any way, their shape and size. One specimen had traces of a caudal fin
which indicated that it was very well developed.

On the whole, it may be said that in general shape, size, number of myotomes,
absence of oral cirri, large size of eye'-spot, and pigment spots on the nerve cord, our
specimens agree with Gunther's B. pelagicum, and it seems quite safe to refer them
to this species.

Branchiostoma indicimi (Willey). — Plate I., figs. 11-13.
Dolichorhynchus indicus, Willey, 1901.

Two specimens, one from Galle (Stu. XXXVI. ), in 4f fathoms, and the other taken
oft* Watering Point (Stn. XXXVIII.) in the same locality, in 9 fathoms, I am
disposed to refer to this species, although the absence of some details in Willey's
description and the lack of figures render the identification a little uncertain.

Both my specimens have long and well-marked preoral lobes, but the proportional
length of the lobes does not appear to be quite as great as in Willey's specimens
(fig. 11). Moreover, the preoral lobes of the Ceylon specimens do not appear bent as
Willey's figures show ; but it may well be that the bending was due to some
accident or injury, and that the lobes are not bent in life.

One of our specimens measures 17 millims., and the other 36 millims. The latter
is a male, and has 29 right gonads and 25 left. The smaller one has no gonads and is
evidently immature. The larger one has a myotome formula of 43, 14, 13 — total, 70 ;
while the smaller one has 41, 14, 14 — total, 69. Both these formulae agree closely
with Willey's description.

The dorsal fin is low and ends conterminously with the myotomes. Its outline in
the large specimens is interrupted by a peculiar wavy break (fig. 1 2), possibly due to
an injury and subsequent healing up. The notochord extends a long way in front ot
the dorsal fin. The nervous system is overlapped by the dorsal fin, while in Willey's
description the arrangement is the reverse of that.

216 CEYLON PEARL OYSTER REPORT.

The posterior extension of the notochord past the myotomes is not very great.
The ventral fin has fin chambers which are also extended postanally, as in
B. lanceolatum and Asymmetron hectori. In the latter species the chambers extend
postanally to the antepenultimate myotome, while here they extend only five
myotomes posterior to the anus. The ventral fin rays are double, and are not
extended postanally as in A. hectori. Willey did not notice the postanal extension
of the fin chambers in his specimens. Only the larger specimen here has ventral fin
rays, showing again what was noticed under B. lanceolatum, var. belcheri, that it is
only in the larger specimens that the ventral fin rays are well developed.

The caudal fin is here well marked off from the dorsal and ventral fins, there being
a well marked supra- and infra-caudal lobe in both specimens (figs. 11 and 13).
There are about 35 to 40 oral cirri of the usual type, bearing sense-papillse. On
the whole it seems fairly certain that these two specimens belong to the species
Branchiostoma indicum. The distribution also favours this conclusion, for the Orissa
Coast of India, where the species was found, is not far north of Ceylon.

Branchiostoma californiense (?), J. G. Cooper. — Plate I., figs. 14, 15.
(?) B. capense, Gilchrist.

There is one specimen, No. V., Table IV., in the collection the identity of which is a
little uncertain. I refer it, with some little hesitation, to Branchiostoma californiense,
J. Cooper. In another paper (10) I have expressed doubt as to the distinctness of
B. californiense and B. capense. Since then Professor Herdman has received from
Dr. Gilchrist eight well-preserved specimens of his B. capense, and has placed them
in my hands for examination. In these I find no trace of an eye-spot. The specimens
range from 51 to 63 niillims. in length, and the number of myotomes from 74 to 76.
The formula varies within 46 to 48, 18 or 19, 9 or 10 — 47, 19, 9 being the most
frequent form. There are 35 pairs of gonads. This formula is so close to that of
B. californiense, and the two agree so well in proportions and characters of the head,
that notwithstanding the absence of an eye-spot I should hesitate to consider the
Cape form distinct until further specimens of the Californian species have been
examined.

The Ceylon specimen was taken in the Cheval district (Stn. XL), at 6 fathoms, on
February 4th, and was 42 niillims. long. It had no gonads and was evidently
immature. Its myotome formula was 40, 20, 12 — total, 72.

The rostral fin is separated from the dorsal fin by a shallow notch. The dorsal fin
is low, and has a series of fin rays. The caudal fin is very slightly marked off from
the ventral and dorsal fins and has its infra-caudal lobe slightly the larger and deeper.
The ventral fin is very long indeed, and has a series of double fin rays running its
whole length. Neither the ventral fin rays nor chambers are prolonged postanally.
The metapleura have a symmetrical termination, thus determining the genus to
which the specimen belongs.

CEPHALOCHORDA. 217

The oral cirri are long, and number about 30. They bear well-marked sense-
papillae. The " Raderorgan " is of the usual type, and has a median dorsal lobe and
two or three lateral lobes on each side.

The notochord projects far in front of the anterior end of the myotomes and
projects posteriorly a little way beyond the last myotome. The dorsal tin ends
conterminously with the myotomes. The nervous system projects anteriorly beyond
the dorsal fin. A well-marked eye-spot is present.

From the above description it will be noticed that this specimen agrees with
B. californiense in all particulars except in the arrangement of the myotomes.

The total number of myotomes is the same in both, but the preatrioporal part is
shorter, and the postanal portion longer in ours than in B. californiense. The
geographical distribution may, at first sight, be supposed to be against this identifi-
cation, for the species is only recorded from San Diego Bay, California, and it is
certainly a noteworthy fact that it should turn up at the other extreme end of the
lndo-Pacific region. But it is not more remarkable than the case of Asymmetron
lucayanum, which was first found in the Atlantic and then in the Pacific Ocean.

Our specimen differs from B. capense, as described by Gilchrist (9), in the number
and arrangement of the myotomes and in the presence of an eye-spot, which is
absent in B. capense. But variation has not yet been much studied in B. capense,
and possibly the full range of the myotomes is not known. It may be, therefore,
that this specimen, and those named B. capense, are only variations of B. califor-
niense, similar to those shown for other species in the tallies at the end of this report.

The habitat of B. capense (Cape Colony) bridges the gap between California and
Ceylon, and it may be added that other species of Acraniates known from the
Maldive Archipelago have been found also at Zanzibar.

It will be seen, therefore, that our Ceylon specimen differs but very slightly from
either B. californiense or B. capense. Both these forms are still comparatively little
known, and a re-examination of both is highly desirable, and would probably confirm
the view I have ventured to express, that these two species are not really distinct.
I believe I am justified in referring this specimen provisionally to B. californiense.

Genus II.— ASYMMETRON, Andrews.

Left metapleuron stops just behind the anus, the right is continuous with the median
ventral fin ; gonads disposed in a single (right) series ; oral cirri with or without
sense-papilla?; intra-buccal tentacles 10 to 16; ventral fin with or without fin
chambers or rays; post-atrioporal cseca 1 to 2 in number.

Asymmetron cingalense (Kirkaldy). — Plate I., figs. 4-7.
Heteropleuron cingalense, KlRKALDY, 1895.
This species was represented by nineteen specimens found sporadically, like
B. lanceolatum, var. belcheri, in Foraminiferal sand in the Gulf of Manaar.

2 F

218 CEYLON PEARL OYSTEE REPORT.

The colour of this species had practically the same range as the others — deep
orange, purplish-pink, and pale fawn tints being found. The dimensions of the
specimens are recorded in Table III. The total length varied from 20 to 36 millims.,
the average being 26 '5 millims.

The specimens were found in the following localities : —

(1.) Half a mile East of Dutch Modragam Paar (Stn. LVL), March 10th,

8 fathoms. Two specimens.
(2.) South of Adam's Bridge (Stn. LTV.), March 8th, 8 fathoms. One specimen.
(3.) Off Karkopani (Stn. TV.), February 2nd, 8 fathoms. One specimen.
(4.) Between the Cheval Paars (Stn. XLVIIL), March 4th, 7^ fathoms. One

specimen.
(5.) South-west of Cheval Paar (Stn. XLIX.), March 1st, 8 fathoms. Two

specimens.
(6.) West of Periya Paar (Stn. XVII.), February 4th, 11 fathoms. Eight

specimens.
(7.) West of Periya Paar (Stn. LXT.)., March 12th, 12 fathoms. Four specimens.

Although so small compared with the specimens of the form B. belcheri, nearly all
were sexually mature — thus showing that the average length of the adult
A. cingalense is much smaller than that of the adult B. belcheri.

Of the nineteen specimens, ten were males and seven were females, while the sex
of two could not be determined. The number of gonads varied from 18 to 26, always
on the right side, the average being 24.

The total number of myotomes varied between 61 and 64, 63 being the average
and most frequent number. The most common myotome formula was 39, 16, 8, which
occurred 10 times out of 19 specimens. The preatrioporal myotomes varied between
37-39, the preanal between 15 and 17. and the postanal between 6 and 8. This
species thus has a comparatively short postanal portion.

The variation in the total number of the myotomes and in their arrangement is
less in this species than in any other species of the group. The fins are fairly
constant throughout the specimens (figs. 4 and 6), and agree well with Kirkaldy's
figures (6). The dorsal fin is deeper anteriorly than in the rest of its extent,
recalling in a lesser degree the condition of A. cultellum (Peters). It has fin
chambers with single fin rays. The dorsal fin in all cases overlaps the nervous
system. The ventral fin is very shallow and has fin chambers with double fin rays
which are very small and difficult to see. The ventral fin chambers are not prolonged
postanally.

In only one of the 19 specimens is the relation of the dorsal fin to the anterior end
of the notochord as figured by Kirkaldy. In that figure the anterior end of the
notochord is but a little way in front of the anterior end of the dorsal fin. This is
seen in but one of the Ceylon specimens, No. X., Table III. (see fig. 5). In the

CEI'HALOCHOKDA. 2 I '.»

remaining 18 (fig. 6) the anterior end of the dorsal fin is much further behind the
anterior end of the notochord. The relation of these two structures to one another
is evidently susceptible of some variation. This receives support from what we know-
in another species. In Asymmetron lucayanum , from the Maldive Archipelago,
FOKSTER-COOPBR (8) has figured the dorsal fin and notochord as ending almost
conterminously at the anterior end, while in Andrews' original figure (3) and in
Kirkaldy's figure (6) of that species the anterior end of the notochord is far in front
of that of the dorsal fin.

In one or two specimens 1 was able to count the oral cirri. They vary from 26 to
32 in number. The intertentacular membrane between the oral cirri of this species
is much deeper than is seen in B laneeolatum, var. belcheri, and extends from
one-third to half the way up. The sensoiy-papiike, on the other hand, are much less
marked. In one preparation of the oral cirri of this species one cirrus was seen to
be branched about one-third of the way up, and the branch was about half as long as
the cirrus.

In No. XIII. , Table III., a curious structure (fig. 7) was noticed in the dorsal fin
just behind the level of the mouth. At this place a break in the fin occurs. A slit
runs downwards and backwards for about the length of 2 myotomes. The slit is
lined throughout by the epithelium that covers the rest of the body. Posterior to
the slit, and continuous with it, is a darker stretch of tissue which looks like a closure
of a former extension of the slit. Sections do not show much more, but the structure
seems to be confined to the dorsal fin. The nervous system, notochord, and other
neighbouring organs are quite unaffected. It is probably the result of some accident
arresting the growth of the fin at this spot during its development.

Asymmetron cultellum (Peters). — Plate I., figs. 8-10.

Epigonichthys cultellus, Peters, 1876; Gill, 1895; Willey, 1901.
Branchiostoma cultellum, Gunther, 1881; and Willey, 1891.
Heteropleuron cultellum, KlRKALDY, 1895.

Only two specimens of this interesting species were present in the collection, one
from near the coral reefs off Vangali (Stn. Lib), March 5th, in 3 fathoms, and the
other from the East Cheval (Stn. XL), February 4th, in 6 fathoms. They were
both quite .small, one measuring 23 millims. and the other 25 millims. Both had
well-developed gonads, one being a male (the smaller of the two), and the other a
female.

It is evident, therefore, that this species, like A. cingalense, is a small one as
compared with B. laneeolatum and its variety beleheri.

The male had 17 gonads and the female 20 gonads, both on the right side. The
myotome formula for the male specimen was 35, 12, 7 — total, 54 ; while that of the

2 v 2

220 CEYLON PEARL OYSTEE REPORT.

female was 35, 12, 8 — total, 55. There is, therefore, quite a close agreement between
the two.

The best distinguishing feature of this species is the dorsal tin, which is so markedly
swollen at its anterior end. This feature alone is usually quite a sufficient indication
of the species (fig. 8). In A. cingalense the dorsal fin is slightly swollen at its
anterior end. This condition is somewhat more emphasised in A. maldivense, a new
species lately described by Forster-Coopee, from the Maldives (8). This new species
seems to bear a remarkable resemblance to the specimens of A. cultellum, from
Ceylon. The resemblance in the shape of the fins in particular is striking. In both
the Ceylon specimens of A. cultellum the fin rays are absent from the ventral fin
chambers.

The female specimen is well preserved and shows the notochord to be distinctly
knobbed, one of the chief characters of the species (fig. 8). The male specimen is not
so well preserved and does not show this knobbed notochord. In both specimens the
dorsal fin overlaps the nervous system, and the notochord is prolonged in front of the
dorsal fin rather more than Kirkaldy shows (figs. 8 and 9). The caudal fin also
differs somewhat from Kirkaldy's figures, for while in the latter it is deeper and
well marked off from the rest of the fins, in the Ceylon specimens the dorsal and
ventral fins fade insensibly into the caudal fin, as shown in A. maldivense (8).

I have been able to confirm Kirkaldy in finding sensory-papillae on the oral cirri
of this species. Willey (4) had previously stated that the cirri were smooth. The
papillae were distinctly present in the female specimen from Ceylon.

CONCLUSIONS.

The whole collection has proved of very great interest in many ways. Although
no new species are recorded, the fact that seven species (including var. belcheri)
of the group occur round I leylon, indicates the great wealth of the Acraniate fauna of
these waters.

Four species are recorded from this neighbourhood for the first time — BranGhiostoma
pelagicum, B. calij hmiense, />'. indicum, and Asymmetron cultellum ; while our
knowledge of the geographical distribution of nearly all the species has been extended
bv this collection.

As regards the habitat of the animals, we have some indication in this collection
that they live commonly in a clean coarse sand, made up, at least to some extent, of
the shells of the large Foraminifera Orbitolites and Heterostegina.

The depths at which the specimens were taken range from 3 to 14 fathoms, in all
cases comparatively shallow water.

CEPHALOCHORDA. 221

The food nt' these tropical forms appears to consist largely of diatoms, especially of
forms found growing over zoophytes, corals, shells, and other submarine objects. In
nearly all, the alimentary canal was seen to contain the skeletons of such forms, and
fsecal pellets showed the same.

The tables at the end of the report show how extremely variable the species of the
group are, and the more extended our knowledge of this group becomes, the less
distinctly do the species appear to be separated. The spawning time of the group In
tropical seas appears to be the latter half of March, rather earlier in the year than in
more temperate seas.

B. lanceolatum is recorded from the Indian < >cean for the first time. It appears to
be a cosmopolitan species, being by far the most widely distributed of all the species.
The tropical forms differ but slightly from their Mediterranean relations.

The variety (as I consider it) B. belcheri is the predominant form in these waters.
and constitutes 60 per cent, of the present collection.

A. cingalense, as might be expected, is also well represented in the collection.

The fact that only two specimens of .-J. cultellitm were found, suggests that Ceylon
may be nearly at the limit of its distribution, and that it becomes more numerous as
we approach Australia.

The re-discovery of B. indicum is interesting, and extends somewhat its known
distribution.

Perhaps the most interesting specimens of the collection were those I have referred
to B. pehxgicum, and it is to be regretted that their state of preservation did not
admit of a more complete study of their anatomy, which would probably show points
of interest. The collection demonstrated, however, definitely, that this species is
truly pelagic.

The most surprising find is B. californiense, which, though showing some slight
variation, is in most respects the same as its American relations.

Finally, this tropical part of the Indian Ocean seems to be either the home of this
group, or is exceedingly well populated, as no less than eight out of the eleven well
characterised species have now been recorded from the seas around Ceylon, as
follows :— -

Branchiostuma lanceolatum

I Mtto, var. belcheri

,-, , r (Herdmajst),

Ceylon I x

L (Andrews ?)

CeyloD (Hebdman),

Singapore (Bedford).

,. , • , ■ ,• [ Orissa Coast of India . . (Willey),

rfranchiostoma indicum . ■ ■{

I Ceylon (Hkrdman)

,, ,• , , • I Indian Ocean (GARDINER)

Uiulf of Manaar .... (Herdman)

222 CEYLON PEARL OYSTER REPORT.

Branchiostoma californiense (?) Gulf of Manaar .... (Herdman).

a 7 n' 1 f(KlRKALDV),

Asymmetron cmgalense . . . ueylon I

I (Herdman).

Asymmetron maldivense . . . Maldives and Zanzibar . . (Gardiner).

Asymmetron cultellum . . . Ceylon (Herdman).

. ± 7 [Maldives (Gardiner),

Asymmetron lucayanum . .1 ) '

[.Zanzibar (Crossland).

The following tables give the numerical details in regard to every specimen in the
collection : —

Table I. — Branchiostoma lanceolatum (10 specimens).

Li i. ality.

(1.) Galle, 7 fathoms j

(2.) 10 miles North of
Cheval Paar, 7 -J
fathoms . . .

(3.) Periya Paar Ker-\
rai, 11 fathoms J

(I.) Off Watering
Point, Galle, t>

fathoms . . .

I.
II.

III.
IV.
Y.

VI.

Number of
gonads.

Myotome formula.

Length.

Sux.

Pre- Pre-

Post-

Total.

atrial.

anal.

anal.

lnillims.

10

m.

21 R. 21 L.

37

12

11

60

36

m.

21 R, 21 L.

37

13

11

61

11

in.

not determined

36

11

13

60

36

f.

21 R. 24 L.

35

11 12

61

26

f.

22 R, 22 L.

37

11

U

59

35

21 R. 24 L.

36

13

12

61

CEPHALOCHORDA.

Table II. — B. lanceolatum, var. belcheri (58 specimens).

223

Locality.

(1.) 10 miles North of
Cheval Paai', 7.1,
fathoms .

(2.) Off Karativo Paar, /

10 fathoms . . \

(3.) Off Karkopani, 8/
fathoms . . . (_

(4.) Off Mutwal Island,

1 4 fathoms .

(5.) Periya Paar Kcr-
rai, 7.1 fathoms .

(6.) Off Ghilaw Paar,
10 fathoms .

(7.) West Cheval Paar,
7i fathoms . .

(8.) Near Periya Paar,
1 1 fathoms . .

.Myotome formula.

,' Length. Sex.

num. her. &

I.
II.

III.
IV.
V.
VI.

VII.

VIII.
IX.

X.
XI.

XII.
XIII.
XIV.

XV.

XVI.
XVII.
XVIII.

Number of
gonads.

Total.

millima.

52
48
52
56
50
46
39

46

40

49

.".9

43
42

54
52
55

48

XIX.

50

XX.

53

XXI.

42

XXII.

43

XXIII.

35

XXIV.

53

XXV.

55

XXVI.

48

XXVII.

52

XXVIII.

49

XXIX.

48

XXX.

52

XXXI.

52

XXXII.

46

XXXIII.

27

XXXIV.

32

XXXV.

35

XXXVI.

33

XXXVII.

28

XXXVIII.

30

XXXIX.

28

XL.

26

XLI.

26

XLII.

26

XLIII.

28

XLIV.

32

f.
f.
f.
f.

m.

f.

f.

immature

f.

m.

m.

none

f.
f.

f.
f.
f.
m.

Pre-

atrial.

37
37
37
37
37
38
38

Pre-

anal.

18
17
18
18
17
18
17

Post-
anal.

64
63
61
64
63
64
64

20 R. 20 L

immature

26 R. 26 L.

27 R. 25 L.
24 P. 26 L.
29 R. 26 L.

38

17

10

65

38

17

9

64

38

17

8

63

39

17

8

64

39

17

10

66

39

17

dam

aged.

38

16

10

64

38

37
38
37

17
17
is
17

9 64

9 63

8 64

9 63

f.

24 R.

24 L.

38

17

9

6-1

m.

21 R. 19 L.

38

17

9

64

—

none

38

16

10

64

f.

23 R. 20 L.

37

17

9

63

—

none

38

17

9

64

f.

28 R. 26 L.

38

—

damaged.

f.

25 R. 25 L.

38

17

9

64

f.

27 R. 25 L.

37

16

10

63

f.

30 R. 27 L.

38

17

10

65

f.

(?) R 15 L.

37

17

9

6:',

f.

27 R. 24 L.

38

17

9

64

f.

27 R. 23 L.

38

17

9

64

f.

25 R 25 L.

38

17

9

64

m.

30 R. 27 L.

38

17

9

64

—

none

37

17

9

63

38

17

9

64

—

39

17

9

65

— .

38

18

9

65

—

38

17

9

64

—

37

17

9

63

—

38

17

8

63

—

,

38

18

9

65

39

17

9

65

—

38

17

9

64

—

39

17

9

65

—

39

17

9

65

224

CEYLON PEARL OYSTEE REPORT.

Table If. — B. lanceulatum, var. beleheri (58 specimens) — continued.

Myot

ome foi

mula.

Locality.

Serial
i nun her.

Length.

Sex.

Number of
gonads.

Pre-

Pie-

Post-

Total.

atrial.

anal.

anal.

millinis.

f

XLV.

47

in.

not counted

37

17

9

63

XL VI.

54

f.

38

18

8

ill

XI .VII.

40

m.

39

17

8

64

XL VIII.

43

f.

39

17

8

64

XLIX.

43

m.

38

17

9

64

(9.) South - west of
Cheval Paar., 8|
fathoms . . .

L.
LI.
LII.

45
49
33

f.
f.

38
38
38

17
17
17

10

8
9

65
63
64

LIII.

25

—

36

18

9

63

LTV.

27

39

17

8

64

LV.

29

—

38

17

9

64

LVI.

35

f.

38

—

damaged.

LVII.

44

in.

38

17

9

64

•

LVTII.

46

f.

38

17

17-4

9

64

Mean

41-64

{

28 f. \
10 in. J

37 • 9

64-3

Mode

—

—

—

—

38

17

9

64

32

1

—

_

3

3

3

I

Table TV. — L, II.. Aaymmetron cidtettum; III., IV.. Branchiostoma indicxcm;

V., B. calif orniewie ('.).

Serial
number.

Number of

gonads.

Myotome formula.

Locality.

Length,
millims.

Sex.

Pre-

Pre- Post-

Total.

a trial.

anal.

anal.

Coral Reefs on' Van-")
gali, 3 fathoms . J

1.

23

in.

17 R.

35

12

7

54

East Cheval Paar, 6 ~l
fathoms . . . . f

II.

25

f.

20 R.

35 12 8

55

Oalle, 4f fathoms . .

III.

36

m.

25 L. 29 R.

43 14 13

70

Off Watering Point, 1
C4alle, 9 fathoms . J

IV.

17

—

none

41 14 H

69

Cheval Paar, 6 fathoms

V.

42

—

none

40 20 12

I

72

CEPHALOCHORDA.

225

Table III. — Asymmetron clngalense (19 specimens).

Myot

ome formula.

Locality.

Serial
number.

Length.

Sex.

Number of
gonads.

Total.

Pre-

Pre-

Post-

atrial.

anal.

anal.

millims.

(1.) Half mile East of "]
Dutch Modra- >

I.
II.

30
31

f.
f.

22 R.
25 R.

39
39

16

15

8
8

6.3

62

gam, 8 fathoms. J

(2.) South of Adam's")

Bridge, 8 I

III.

32 '5

m.

26 R.

39

16

9

64

fathoms . . .J

(3.) Off Karkopani, 8 "1 ! jy
fathoms . . . J

36

f.

25 R.

39

17

6

62

(1.) Cheval Paar, 7A \
fathoms . . .J

V.

25

m.

23 R.

37

16

9

62

(5.) South - west of "|

VI.

25

m.

22 R.

39

16

9

64

Cheval Paar, 8 f
fathoms . . .J

VII.

29

f.

uncertain

37

17

7

61

r

VIII.

31-5

m.

18 R.

39

17

8

64

IX.

30

m.

23 R.

39

16

8

63

X.

31

m.

23 R.

39

16

8

63

(6.) West of Periya

XL

23

f.

24 R.

39

16

8

63

Paar, 1 1 fathoms "

XII.

24

m.

22 R.

39

16

8

63

XIII.

24

f.

25 R.

39

16

8

63

XIV.

23

m.

23 R.

39

16

8

63

.

XV.

20

m.

18 R.

39

16

8

63

f XVI.

21

_

24 R.

39

16

8

63

(7.) West of Periya J XVII.

25

f.

24 R.

39

16

8

63

Paar, 12 fathoms 1 XVIII.

22

m.

21 R.

39

16

8

63

1

XIX.

23

—

22 R.

39

16

8

63

Mean

—

26-5

r 7f. -i

X 10 m. J

21 -6 R.

38-8

16-1

8

63-7

Mode

— ■

—

—

—

39

16

8

63

—

17

—

9

3

3

4

4

2 0

226 CEYLON PEARL OYSTER REPORT.

LITERATURE CITED.

(1.) 1884.— Gunther, 'Zool. Collections, H.M.S. "Alert,"'

(2.) 1889. — Gunther, ' Challenger Reports,' vol. 31.

(3.) 1893. — Andrews, 'Studies Biol. Lab. Johns Hopkins University,' vol. 5, No. 4.

(4.) 1894.— Willey, 'Q. Journ. Mic. Sci.,' vol. 35.

(5.) 1894.— Kirkaldy, 'Rep. Brit, Assoc, Oxford.'

(6.) 1895.— Kirkaldy, ' Q. Journ. Mic. Sci.,' vol. 37.

(7.) 1901.— Willey, ' Q. Journ. Mic. Sci.,' vol. 44.

(8.) 1902. — Forster-Cooper. ' Fauna and Geography of Maldives and Laccadives,'

vol. 1, Part 4.
(9.) 1902.— Gilchrist, ' Marine Investigations in S. Africa,' vol. II.
(10.) 1903.— Tattersall, 'Trans. Liverpool Biol. Soc.,' vol. XVII., p. 269

EXPLANATION OF PLATE.

Fig. 1. Caudal fin of Branchiostoma lanceolatum. All the Ceylon specimens conform more or less to this

type.
Fig. 2. Head of No. IV., Table I., B. lanceolatum, to show the dark patch anterior to the dorsal fin

and dorsal to the notochord.
Fig. 3. Caudal fin of B. lanceolatum, var. beldieri. Very uniform throughout the Ceylon specimens.
Fig. 4. Caudal fin of Asymmetron cingalense.
Fig. 5. Anterior end of No. X., Table III., A. cingalense, the only one in which relation of notochord

to dorsal fin anteriorly is the same as in Kirkaldy's figure.
Fig. 6. The general arrangement of the anterior end of the Ceylon specimens of A. cingalense.
Fig. 7. Anterior end of No. XIII., Table III., A. cingalense, to show peculiar structure in the dorsal fin.
Fig. 8. Female A. cultelhim.

Fig. 9. Anterior end of male A. cultelhim. Notochord not definitely clubbed.
Fig. 10. Caudal fin of male A. cultelhm.
Fig. 11. B. indicum.

Fig. 12. Anterior end of large B. indicum.
Fig. 13. Caudal fin of large B. indicum.
Fig. 14. Anterior end of B. calij 'orniense (1).
Fig. 15. Posterior end of B. californiense (1).
Fig. 16. B. pelagicum.

CEYLON PEARL OYSTER REPORT.

CEPHALOCHORDA.

[CEYLON PEARL OYSTER FISHERIES— 1903— SUPPLEMENTARY REPORTS, No. VII.]

REPORT

ON THE

COPEPODA

COLLFX'TED BY

Professor HERDMAN, at CEYLON, in 1902.

BY
ISAAC C. THOMPSON, F.L.S., and ANDREW SCOTT, A.L.S.

[With PLATES I. to XX.]

The Copepoda contained in the collections brought home by Professor Herdman
may be conveniently divided into four sections, viz. : — (1) those obtained during the
voyages out and home ; (2) those collected by the tow-net around the Island of
Ceylon ; (3) those obtained by examination of washings from dredged material
(Ascidians, Sponges, Corals, Pearl Oysters, &c); and (4) the parasitic species found
attached to fishes. The collection was contained in 122 bottles, each bottle repre-
senting a gathering from one of the stations shown in the appended list. The free-
swimming species naturally form by far the largest part of the collection, although
they do not contain most of the novelties. Some of the gatherings were preserved in
formol, and others in alcohol. Out of the total number, those marked 1 to 41 were
collected on the voyages to Ceylon and home, and most of the others during Professor
Herdman's three months' work round Ceylon, while some have been sent since by
Mr. Hornell as the result of his further work. Professor Herdman's method of
collecting material from a fast steamer has already been described in the ' Transactions
of the Liverpool Biological Society.' The water containing the material enters the
ship some feet below the surface and is pumped into the tank from which baths, &c,
are supplied. On this occasion he was fortunate enough to have the entire use of one
of the bath-rooms, a tow-net being fixed to the tap so that sea-water was running
through it day and night. By this means it is practicable to collect material from
the whole of the route traversed, and mostly in good condition.

This collection of Copepoda has proved to be exceedingly rich and varied, containing

2 G 2

228

CEYLON PEARL OYSTER REPORT.

as it does no less than 283 species, of which 76 are new to science, while at least ten
new genera are required. The list of new forms is as follows : —

Ridgewayia typica, n. gen. & sp.
Centropages tenuiremis, n. sp.
C. dorsispinatus, n. sp.
Pomtella dame, var. ceylonica, nov.
Labidocera pectinata, n. sp.
L. hroyeri, var. stylifera, nov.
„ var. gallensis, nov.
Pontellopsis herdmani, n. sp.
Sunaristes inopinata, n. sp.
S. lorujipes, n. sp.
S. curticaudata, n. sp.
Tegastes imthurni, n. sp.
T. donnani, n. sp.
T. I w i/i) a mi, n. sp.
T. cJtalmersi, n. sp.
Stenhelia brewcornis, n. sp.
S. gracilicaudata, n. sp.
5. longkornis, n. sp.
S. perplem, n. sp.
& dentipes, n. sp.
5. minuta, n. sp.
iS'. hnoxi, n. sp.

Parastenhelia hunt' Hi, n. gen. & sp.
P. similis, n. sp.
Ameira minor, n. sp.
^P tenuipes, n. sp.
Ceylonia aculeata, n. gen. & sp.
Laophonte hirsuta, n. sp.
Laophontella typica, n. gen. & sp.
Tetragoniceps dubia, n. sp.
P. minor, n. sp.
Dadylophusia dentata, n. sp.
22. havelocki, n. sp.
Z>. hirsuta, n. sp.
P. ceylonica, n. sp.
P. hamiltoni, n. sp.
P. robusta, n. sp.
P. laticaudata, n. sp.
P. irmula, n. sp.
P. platysoma, n. sp.

Peltidium ovule, n. sp.

P. angulatwn, n. sp.

P. specioswm, n. sp.

P. serratum, n. sp.

.P. perplexnm, n. sp.

PorceUiilinm brericaudatuin, n. sp.

P. acuticaudatum, n. sp.

P. ravance, n. sp.

Pseudanthessius maximiis, n. sp.

P. chelifer, n. sp.

P. concinnus, n. sp.

Lichomolgus gracilis, n. sp.

P. ieversi, n. sp.

P lankensis, n. sp.

L. buddhensis, n. sp.

Z/. simplex, n. sp.

i. elegans, n. sp.

P. robustus, n. sp.

P .'//.</"*, n. sp.

P. dentipes, n. sp.

Paralichomolgus cwrticaudatus n. gen. & sp.

P. longicaudatus, n. sp.

Hermarmella rohusta, n. sp.

77. serendibica, n. sp.

Hersiliodes leggii, n. sp.

/P. tamilensis, n. sp.

iP <M>«i, n. sp.

Asterocheres manaarensis, n. sp.

^P major, n. sp.

^P minor, n. sp.

Asteropontiiis typicus, n. gen. & sp.

^P attenuates, n. sp.

Colloeheres giesbrechti, n. sp.

Lepeopsyllus typicus, n. gen. & sp.

P. <«'«/«, n. sp.

Doropontius denticornis, n. gen. & sp.

Cletopontius serratus, n. gen. & sp.

Stephopontius typicus, n. gen. & sp.

Chondracanthus cynoglottidis, n. sp.

The large majority of these new species were found in the gatherings from the
pearl hanks in the Gulf of Manaar, where Professor Herdman and Mr. Hornell were
working for some weeks. The dissection and drawing of so many new forms has
involved a vast amount of close labour and diligent research, and Mr. Thompson must

COPEPODA.

229

here be allowed to state that this portion of the work, and indeed the chief part of the
laborious examination of the material, was undertaken and has been skilfully carried
out by Mr. Andrew Scott, whose previous experience of this group of animals makes
his co-operation invaluable.

The species, known and new, from the collection represent the families as follows : —

Calanidas .
Centropagidse .
Pseudocyclopida^
Candaciidse .
Pontellidaj
Cyclopidre
Ascidicolidse .
Harpacticidge

44 species.
29

1
10

31

3

78

Oncseidae .
Coryca3idae .
Lichomolgidse
Asterocherida?
Ergasilidee
Caligidee . .
Chondracanthida?
Lernceopodidse .

8 species.
29
13
18

2

4

List of Collecting Stations.
I. Voyage Out (Stations 1 to 2 4).

1. English Channel to Gibraltar (36 species) Dec. 28-31, 1901.

2. Gibraltar to Marseilles (25 „ ) Jan. 2, 1902.

3. Marseilles to Messina . (38 ,, ) „ 5

Erratum.

For Dactijlophwiia read Daetylopusia throughout Report on Copepoda.

17.

18.
19.
20.
21.
22.
23.
24.

• .(41 „ ) ,

17

55

(coarse net)

. . (39 „ ) ,

17

) )

(mostly fine net) .

. . (36 „ ) ,

18

)>

(coarse net)

• .(35 „ ) ,

18

off Minikoi (coarse net) .

. .(56 „ ) ,

19

ji

. . (56 „ ) ,

19

Maldives to G. of Manaar(coars

e net) (40 „ ) ,

20

>>

(fine ]

let) (42 „ ) ,

20

228

CEYLON PEAEL OYSTER REPORT.

as it does no less than 283 species, of which 76 are new to science, while at least ten
new genera are required. The list of new forms is as follows : —

Ridgewayia ti/piat, n. gen. & sp.
Centrqpages tenuiremis, n. sp.
C. dorsispinatus, n. sp.
l'oniilhi tlamv, var. reyhmira, nov.
Labidocera pedinata, n. sp.
L. kroyeri, var. stylifera, nov.
„ var. gallensis, nov.
Pomtellqpsis herdrnani, n. sp.
Smomstes inopinata, n. sp.
S. longipes, n. sp.
S. curticwudata, n. sp.
Tri/aatis initial mi, n. sp.
T. donnani, n. sp.
T. twynami, n. sp.
T. chalmersi, n. sp.
Stenht lia brt vicorrris, n. sp.
S. gracilicaudata, n. sp.
.S1. longicornis, n. sp.
S. perpleoca, n. sp.
& dentipes, n. sp.
)S'. minnht. n. sn

Peltidium ovale, n. sp.

P. angulation, n. sp.

P. spedoswm, n. sp.

P. serratvm, n. sp.

P. perplexmn, n. sp.

Porcellidium brevicaudatwm, n. sp.

P. acuticaiidatiiiii, n. sp.

P. ravance, n. sp.

Pseudanthessius maximus, n. sp.

P. ehelifer, n. sp.

P. ivncinnus, n. sp.

Liclwmolgwi gracilis, n. sp.

P. ieversi, n. sp.

P lankensis, n. sp.

P. buddhensis, n. sp.

P simplex, n. sp.

L. elegans, n. sp.

P. robustus, n. sp.

P ;//;/(?.*, n. sp.

P. dentipes, n. sp.

7) . . .7.--.T. 7 — .

P. robusta, n. sp.
P. laticaudata, n. sp.

P. mnula, n. sp.
P. platysoma, n. sp.

^mravuTWftbO utytulLurltts, II. g<^II. OS Sp.

Cletopontius serratiis, n. gen. & sp.
Stsplwpontius typicus, n. gen. & sp.
Chondracanthus cynoglottidis, n. sp.

The large majority of these new species were found in the gatherings from the
pearl hanks in the Gulf of Manaar, where Professor Herdman and Mr. Hornell were
working for some weeks. The dissection and drawing of so many new forms has
involved a vast amount of close labour and diligent research, and Mr. Thompson must

COPEPODA.

229

here be allowed to state that this portion of the work, and indeed the chief part of the
laborious examination of the material, was undertaken and has been skilfully carried
out by Mr. Andrew Scott, whose previous experience of this group of animals makes
his co-operation invaluable.

The species, known and new, from the collection represent the families as follows : —

8 species.
29
13
18

2

4
se . 2

3

Oalanidae ....

44 species.

Oncseidee .

Centropagidse .

• 29 „

Corycaeidse .

Pseudocyclopidas .

• 1

Lichomolgidte

Candaciidae .

• 10 „

Asterocheridae

Pontellidas

• 31 „

Ergasilidae

Cyclopidoe

8

Caligidse .

Ascidicolidae .

3

Chondracanthid

Harpacticidse

• 78 „

Lernteopodidge

1.

2.
3.
4.

List of Collecting Stations.
I. Voyage Out (Stations 1 to 2 4).
English Channel to Gibraltar (36 species

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.

(25

(38

(38

(31

(28

300 miles south . (44

(«

Gibraltar to Marseilles .
Marseilles to Messina .
Messina to Port Said . .
Port Said to Suez .
Gulf of Suez ....
South end of Gidf of Suez to

Red Sea

South end of Red Sea (coarse net) (37

,, ,, (fine net) (45

Perim to 200 miles into Indian Ocean (fine net) . (43

,, ,, ,, (coarse net) (33

Indian Ocean, south of Socotra (fine net) . . . (53

,, ,, (coarse net) . . (53

going east (fine net) (59

,, (coarse net) .... (47

(fine net) (41

,, (coarse net) .... (39

(mostly fine net) . . . (36

,, (coarse net) .... (35

off Minikoi (coarse net) . . . . (56

,, (line net) (56

Maldives to G. of Manaar (coarse net)(40
„ (fine net) (42

Dec. 28-31, 1901.
Jan. 2, 1902.
5

9
10
11
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20

230

CEYLON PEARL OYSTER REPORT.

25.

26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.

42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.

II. Voyage Back (Stations

Colombo to Minikoi (return voyage)

Minikoi onwards to west

Indian Ocean, further west

South of Aden to Red Sea
Red Sea

Gulf of Suez and Suez Canal . . . .

Suez Canal (12 hours)

Port Said, Mediterranean onwards
South of Crete (air 63° F., sea 63"5° F.)

Crete to Messina

Messina to Sardinia

Strait of Bonifacio to Marseilles . .

25 to 41).

(17 species
(41

(41

(36
(40
(33
(27
(33
(22
(26
(21
(12
(23
(20
(16
( 6
( 9

III. Round Ceylon.

Four hauls off Negombo (Station I.*) . . . . (11 species

Off Chilaw (Station III.) (25

Chilaw Paar (Station V.) (18

Off Kalpentyn Island — night and early morning ( 1 1

Muttuvaratu Paar, 11.30 a. m (18

Cheval and Periya paars (29

Pamban Pass, 8 a.m (18

Palk Bay (Station XVIII.) (6

Back Bav, Trincomalee (Station XX.) . . . . ( 8

,, &c, Trincomalee (9

Surface, 5 miles east of Arugarn Bay .... (26

Galle, after dark, 9 p.m (11

8 p.m (9

,, surface outside bay, daylight (36

Off Pantura, south of Colombo (26

North of Karativo, Kodramallai Point .... (22
2f miles S.S.W. of Chilavaturi, bottom 15 fathoms (14

To south of Cheval Paar (41

Modragam Paar (19

* Stations with roman numerals, in brackets, are the dredging stations (see

April

9
10
11
12
13
14
15
16
17
18

20

21

22
23

8-9, 1902.

-10

-11

-12
-13

14

15

16
-17

18

19

19
-21

22
-23

24

24

Jan. 31, 1902.

Feb. 1

2

2-3

3

4

5

6

7

8

12

14

15

17

19

25

26

26

March 1

'Narrative," p. 17).

COPEPODA.

231

61.

62.

63.

G4.

65.

66.

67.

68.

69.

70.

71.

72.

73.

74.

75.

76.

77.

78.

79.

80.

81.

82.

83.

84.

85.

86.

87.

88.

89.

90.

91.

92.

93.

94.

95.

96.

97.

98.

99.
100.
101.

Off south bar, Manaar, surface.

Off Manaar Island

Cheval Paar

North of East Cheval Paar (Station LII.) . . .
10 miles N. of Cheval, bottom net, 7 fins. (Sta. LI1T.)

South of Adam's Bridge, 12 fathoms

surface

Dutch Modragam Paar, surface ....
Karativo Paar, 6 to 10 fathoms ....
Donnan's Muttuvaratu Paar, 8 fathoms
West of Periya Paar, deep net ....
Vankali Paar, 9 fathoms (phosphorescent) .

South-east of Modragam

Off Mutwal Island

Chilaw Paar (Station LXIX.)

Donnan's Muttuvaratu Paar

Mudalaikuli Paar

Talaivillu Paar, all day

Navakaddu Paar

Galle

,, Bay

,, Harbour

,, 9 A.M

Harbour

8 A.M.

9 A.M.

„ 5 P.M

Pearl banks, washed from Medusae

Galle, 3 p.m

South-east Cheval Paar, at anchor
East Cheval Paar, centre .

Periya Paar Kerrai, daylight
night .
West Cheval

10

12

35

21

28

22

15

23

22

17

23

28

15

15

10

12

12

35

21

22

11

5

4

7

o

8

16

3
.>

6

1
11

4
15

2

9
3

10
9

12

species

March 3, 1902.

1»

3

11

4

11

4

))

5

6

7

7

.,

8

..

10

..

10

. ,

11

13

11

13

Ji

17

11

19

11

20

11

29

11

30

April

1

5?

•_>

June

5

,,

14

July

n
O

11

7

11

12

11

15

11

20

,3

31

August

1

i)

8

(no date)

August

12

Nov.

11

)»

6

ii

7

j •

8

ii

9

i )

9

ii

10

11

232

CEYLON PEARL OYSTER REPORT.

102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.

Periya Paar, night (9 species

South-west Cheval (2 ,,

Kondatchi Paar (5 ,,

Muttuvaratu Paar (4 ,,

,, pearl oyster washings (46 ,,

Cheval Paar (8 ,,

Pearl banks, washings from dredged debris. . . ( 6 „

Washings from young peai'l oysters (3 „

,, „ deep water dredgings, Pt. de Galle ( 3 „

General washings of dredged Invertebrates . . (41 ,,

Washings from dredgings, G. of Manaar sponges. (13 ,,

Tow-net off Marichchukaddi (11 ,,

Modragam Paar, surface (15 ,,

Karativo, shoal buoy (14 ,,

South-east Cheval Paar, surface (12 ,,

East Cheval, surface (8 ,,

Cheval Paar (14 ,,

,, ,, (only young Calanus vulgaris

East Cheval Paar

Washings from Cheval Paar pearl oysters .

. ( 5 species
• ( 1 ,,

Nov. 13, 1902.

14

17

19

19
Feb. & Mar., 1902,

Feb.

1, 1903.

2

4-5

7

March 10

20

April 18

Distribution of Species.

The Numbers refer to the Stations in the ■preceding List.

Calanus helgolandicus, 1, 2, 3, 37, 38, 41.
gracilis, 4, 21, 22, 38.
„ minor, 2, 3, 4, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 24, 31,

34, 38, 39, 41, 43, 46, 47, 48, 49, 69, 78, 81, 92.

„ pauper, 3, 4, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 19, 21, 22, 24, 26, 27,

28, 29, 30, 31, 32, 33, 34, 42, 43, 47, 49, 51, 52, 54, 55, 56, 60,

62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 7d, 79, 80, 94,

96, 98, 99, 102, 113.

darwini, 5, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29,

30, 31, 32, 33, 54, 68, 74, 80, 103.
vulgaris, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 26,
27, 28, 29, 30, 31, 32, 33, 34, 42, 44, 45, 46, 47, 49, 50, 52, 53,
55, 56, 57, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73,
74, 75, 76, 77, 78, 79, 80, 92, 94: 100, 101, 102, 104, 116, 117,
118, 119, 120.

COPEPODA. 233

Calanus robustior, 21.

Eucalanus attenuatus, 8, 10, 11. 12, 13, 14, 15, 1G, 17, 18, 20, 21, 22, 23, 24, 59,

64, 71.
,, pileatus, 8, 9, 24, 55.

crassus, 9, 5G, 57, 100, 117.

subcrassus, 9, 10, 12, 21, 32, 47, 50, 55, 57, G3, GG, G9, 72, 93, 95, 97,
98, 99, 100, 101, 102, 104, 105, 107, 115, 116, 118
,, subtenuis, 47, 55, G2, 63, 65, 74, 76, 78, 79.
,, monachus, 46, 79.

Ilhincalanus cornutus, 13, 14, 15, 16, 17, 18, 19, 56, 57, 78.

uasutus, 14, 15, 17, 18, 20, 21, 56, 64.
Mecynocera clausi, 7, 8, 13, 14, 15, 18, 19, 20, 21, 22, 25, 27, 28, 29, 30, 31, 32, 33,

34, 37, 42, 43, 56, 65, 71, 72, 76.
Paracalanus parvus, 1, 2, 3, 4, 6, 7, 8, 10, 11, 13, 14, 15, 16, 17, 18, 21, 22, 24, 25,

2G, 27, 29, 30, 31, 32, 33, 34, 35, 42, 43, 45, 47, 50, 51, 52,
53, 55, 56, 58, 59, 60, 64, 65, 66, 68, 69, 70, 71, 72, 76, 78,
79, 80, 81, 94, 95, 96, 107, 113, 114, 115, 116, 117,
118, 121.
„ crassirostris, 42, 43, 47, 50, 51, 55, 63, 65, 68, 69, 70, 78, 79, 80,

94, 113.
Metacalamis aurivillii, 26, 27, 28, 29, 43, 47, 48, 55, 58, 59, 60, 64, 65, 66, 69, 70,

71, 72, 92, 96, 107, 113, 114, 115, 116, 118, 121.
Acrocalanus gibber, 6, 22, 59, 64.

longicornis, 7, 8, 9, 10, 11, 13, 15, 16, 18, 24, 28, 32, 34, 42, 43, 55,
56, 59, 60, 63, 65, 66, 67, 68, 73, 78, 79, 94, 96, 107,
114, 115, 117.
gracilis, 7, 10, 11, 19, 20, 21, 22, 27, 64.
,, monaclms, 27, 29.

Calocalanus pavo, 1, 2, 3, 4, 7, 8, 11, 13, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26,
27, 28, 29, 30, 32, 33, 37, 52, 55, 69, 72, 74, 75, 78.
plumulosus, 4, 5, 7, 10, 11, 15, 18, 22, 24, 56, 71, 78.
Clausocalanus furcatus, 1, 3, 4, 6, 7, 8, 10, 11, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23,

24, 27, 28, 29, 30, 31, 32, 33, 34, 37, 38, 39, 40, 41, 42,
43, 52, 55, 56, 62, 68, 70, 71, 72, 73, 74, 75, 77, 78.
arcuicornis, 1, 2, 3, 4, 6, 8, 9, 15, 26, 27, 28, 29, 30, 31, 37, 38, 39,
40, 41, 68.
Pseudocalanus elongatus, 1, 2, 3, 4, 6.
iEtideus armatus, 3, 4, 6.
Uudeuchseta minor, 1, 16, 21.
Euchirella rostrata, 21, 23.
,, messinensis, 26.

2 H

234 CEYLON PEARL OYSTER REPORT.

Euchseta marina, 1, 2, 3, 4, 7, 8, 9, 10, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
24, 26, 27, 28, 29, 30, 31, 32, 50, 55, 56, 57, 71, 74, 78, 94, 99.
,, spinosa, 2, 3, 30.
,, acuta, 3, 4.

concinna, 9, 10, 34, 100, 102, 104, 105.
barbata, 28, 29.
Scolecithrix dana3, 12, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 74, 77.
bradyi, 3, 14, 15, 21. 22, 23.
,, chelipes, 34.

,, auropecten, 8.

,, tenuipes, 8.

Pddgewayia typica, n. gen. & sp., 106.
Pbaenna spinit'era, 1, 9, 20.
Centropages chierchiaB, 1, 2, 21, 22, 64.
typicus, 2, 3, 37.

violaceus, 3, 7, 13, 16, 18, 37, 38, 40, 41, 52, 59.
furcatus, 6, 9, 10, 11, 13, 14, 15, 16, 24, 26, 27, 31, 32, 34, 35, 46, 48,

55, 56, 59, 63, 64, 65, 66, 68, 69, 74, 78, 115.
elongatus, 7, 15, 21, 22, 24, 27, 30, 34.
gracilis, 7, 10, 16, 17, 18, 22, 26, 28, 29, 30, 34, 35, 55, 56.
,, kroyeri, 13, 14.

calaninus, 15, 17, 18, 19, 20, 21, 26, 27, 56, 59, 72.
orsini, 30, 46, 59, 64, 65, 70, 71, 76, 78, 79, 80.

tenuiremis, n. sp., 13, 43, 47, 53, 54, 56, 59, 60, 63, 64, 65, 69, 70, 71,
79, 94, 96, 98, 99, 101, 107.
,, dorsispinatus, n. sp., 75.

Isias clavipes, 1.
Pseudodiaptomus salinus, 5, 6, 7, 35, 36, 37.

serricaudatus, 11, 13, 15, 43, 53, 54, 55, 57, 58, 59, 61, 70, 71,

72, 79, 80, 91, 92, 107, 113.
aurivillii, 47, 48, 59, 60, 65, 66, 69, 80.
Temoropia mayumboensis, 6, 7.
Temora longieornis, 1,4.

discaudata, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 21. 22, 23,
24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 42, 43, 45, 47, 48,
52, 55, 56, 57, 59, 60, 61, 63, 64, 65, 66, 68, 69, 70, 71, 73,
74, 75, 76, 98, 99, 100, 101, 114, 116, 118.
,, stylifera, 9, 10, 11, 12, 13, 14, 15, 16, 17, 20, 21, 22, 23, 24, 43, 52.
turbinata, 43, 59, 64, 73, 82.
Metridia lucens, 1, 2, 3, 4, 5.

Pleuromamma gracilis, 1, 2, 3, 4, 11, 12, 13, 14, 15, 16, 21, 22, 23, 24, 26, 27, 28,

29, 30, 32, 33, 34, 35, 39.

COPEPODA.

235

Pleuromamma xiphias, 1.

abdominalis, 3, 4, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 26, 27, 28, 29, 30, 32, 33, 34, 35.
Lucicutia flavicornis, 1, 2, 3, 4, 5, 7, 8, 13, 15, 21, 22, 23, 26, 27, 28, 29, 30. 37.

38, 39, 78.
Heterorhabdus spinifrons, 3, 11, 13, 14, 16, 21, 22.
papilliger, 12.
,, abyssalis, 12.

,, clausi, 27.

Pseudocyclops obtusatus, 15, 108, 122.
Candacia armata, 1.

simplex, 3, 9, 10, 11, 13, 14, 16, 23, 32, 55, 59, 63, 64, 94, 98, 99, 100,

101, 102.
,, bispinosa, 3, 9, 37.

bradyi, 7, 9, 10, 11 , 13, 15, 20, 24.

truncata, 7, 8, 13, 14, 16, 17, 20, 21, 22, 23, 24, 26, 29, 33, 34, 55, 56,

100, 117.
catula, 7, 8, 13, 15, 16, 21, 22, 26, 27, 29, 32, 34, 55, 56, 59, 77, 78.
,, longimana, 9, 10, 11.

sethiopica, 9, 13, 14, 16, 17, 18, 20, 21, 22, 23, 24, 26, 27, 28, 29,

30, 72.
curta, 9, 10, 11, 14, 56, 99.

pacbydactyla, 14, 16, 17, 20, 21, 22, 23, 30, 56, 72, 74.
Calanopia elliptica, 5, 7, 9, 10, 11, 12, 13, 14, 21, 22, 23, 24, 32, 35, 36, 37, 43, 47,

48, 49, 52, 54, 55, 57, 58, 59, 64, 67, 68, 69, 72, 75, 77, 79,
102, 114, 116.
minor, 7, 9, 10, 14, 15, 22, 23, 24, 26, 32, 35, 36, 42, 43, 47, 48, 59, 64,

66, 70, 78, 79, 92, 94, 96.
aurivillii, 82, 83, 85, 90, 114, 115, 118, 121.
Labidocera acuta, 5, 9, 10, 11, 12, 13, 14, 15, 20, 21, 23, 26, 31, 32, 45, 46, 47, 48,
49, 52, 55, 57, 59, 60, 61, 63, 64, 65, 66, 69, 73, 74, 75, 76,

102, 103, 113, 116, 117.

minuta, 9, 12, 13, 14, 15, 16, 31, 33, 43, 46, 47, 48, 55, 59, 68, 71, 73,

98, 99, 100.
detruncata, 17, 19, 20, 21, 26, 27, 50.

pavo, 46, 50, 51, 53, 54, 55, 57, 58, 59, 60, 61, 65, 93, 98.
kroyeri, 45, 46, 57, 65, 98, 99, 100, 101, 102, 103, 117.
,, var. stylifera, 72, 75, 76, 77, 93.
,, var. gallensis, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58.
pectinata, n. sp., 48.
Pontella danse, var. ceylonica, 46, 57, 60, 63, 65.

2 h 2

236 CEYLON PEARL OYSTER REPORT.

Pontella fera, 21, 26, 74.

„ securifer, 22, 46, 59, 60, 62, 63, 66, 72, 77, 105.
,, princej:>s, 77.
,, tenuiremis, 49.
Pontellina plumata, 7, 9, 14, 15, 21, 22, 23, 26, 27, 28, 29, 30, 33, 52, 72, 76, 97.
Pontellopsis krameri, 8, 10, 33, 34.

armata, 23, 75, 76, 77, 80, 94, 96, 98, 100, 103.
regalis, 39.
,, herdmani, n. sp., 54, 57.

,, strenua, 47, 52.

,, perspicax, 47.

Acartia clausi, 1, 2, 4, 5, 59.

„ longiremis, 1, 2, 3, 4, 6, 36, 37, 38, 39.
,, dubia, 5, 7.

„ erythnea, 5, 6, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 31,
35, 36, 43, 46, 47, 48, 49, 50, 53, 54, 55, 57, 58, 59, 60, 61,
62, 63, 66, 67, 68, 70, 71, 77, 78, 79, 80, 92, 94, 96, 97, 98,
100, 101, 103.
centrum, 5. 8, 49, 50, 53, 55, 58, 93.
„ negligens, 7, 8, 10, 11, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27. 28,
29, 30, 31, 33, 34, 35, 38, 50, 52, 56, 64, 6G, 71, 75, 76, 78,
79, 81, 94, 100.
Tortanus gracilis, 6.

,, forcipatus, 45, 47, 56.
Thorellia brunnea, 112.

Oithona plumifera, 1, 2, 6, 7, 8, 11, 13, 14, 15, 17, 18, 19, 20, 21, 22, 24, 26, 27,

28, 29, 30, 31, 32, 33, 37, 38, 39, 42, 55, 56, 60, 65, 67,
68, 71, 72, 78, 81, 107, 118.
similis, 5, 6, 7, 10, 14, 15, 17, 19, 20, 21, 22, 23, 24, 35, 36, 38, 42, 43,
47. 52, 56, 57, 58, 59, 64, 65, 66, G7, 68, 69, 70, 71, 78, 80,
81, 92, 113, 114.
minuta, 13, 14, 18, 19, 20, 22, 25, 26, 27, 28, 29, 31, 45, 46, 47, 50, 51,
52, 53, 54, 56, 59, 61, 63, 64, 65, 66, G7, 69, 71, 78, 79, 80,
81, 114.
rigida, 25, 26, 32, 42, 43, 52, 54, 58, 59, 62, 64, 69, 71, 72, 78, 79, 96,

107, 116, 118, 121.
spmifrons, 1, 2, 3, 4, 8, 9, 10, 11, 13, 24.
,, nana, 47, 114, 115.

setigera, 36, 37, 38, 39, 41.

'•& ^ ' . > from Ascidians, Ceylon.
„ normani, J

COPEPODA. 237

Botryllophilus ruber, from Sponges, Ceylon.
Sunaristes paguri, 111.

,, inopinata, n. sp., 111.

, . longipes, n. sp. , 111.

,, curticaudata, n. sp., 111.

Longipeclia coronata, 35, 36, 38.

,, minor, 113.

Canuella perplexa, 5.

Ectinosoma atlanticum, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,

21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
36, 37, 39, 40, 41, 42, 43, 45, 46, 47, 51, 52, 54, 56, 57,
58, 60, 61, 64, Gd, 66, 67, 68, 69, 71, 72, 73, 78, 79, 80.
81, 92, 113, 115.
roseum, 2, 5, 6, 7, 8, 10, 11, 13, 14, 15, 17, 18, 19, 21, 22, 23, 24, 25,
26, 28, 29, 30, 31, 32, 33, 34, 35, 37, 42, 43, 45, 46, 48, 52,
53, 54, 56, 57, 58, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71,
72, 73, 78, 79, 80, 81, 92, 114, 115.
,, normani, 106, 111.

,, propinquum, 106, 111.

Setella gracilis, 3, 6, 7, 8, 11, 13, 14, 15, 16, 18, 19, 21, 22, 23, 24, 25, 27, 30, 31,
33, 34, 35, 37, 38, 43, 47, 51, 52, 55, 56, 59, 62, 64, 66, 71, 72,
73, 78, 79, 80, 81, 115. 116, 118.
Miracia efferata, 19, 22, 24, 26.

,, minor, 1, 13, 15.
Euterpina acutifrons, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 18, 25, 29. 32, 35,

36, 39, 45, 46, 47, 48, 51, 52, 53, 56, 57, 58, 59, 60, 61,
63, 64, 66, 67, 68, 69, 73, 78, 80, 92, 113, 115, 116, 117, 118.
Tachidius littoralis, 6.
Clytemnestra scutellata, 11, 12, 13, 14, 15, 18, 19, 21, 22, 24, 56 62, 118.

rostrata, 15, 16, 27, 28, 30, 31, 33, 37, 78.
Tegastes sphasrica, 5.
,, nigrans, 106.

imthurni, n. sp. , 106.
,, donnani, n. sp., 106.
,, twynami, n. sp., 106.
,, chalmersi, n. sp., 106.
Stenhelia brevicornis, n. sp., 106.
,, gracilicaudata, n. sp., 106.

,, longicornis, n. sp., 106.

,, perplexa, n. sp., 106.

,, dentipes, n. sp., 106.

238 CEYLON PEARL OYSTER REPORT.

Stenhelia minuta, n. sp., 106.

„ knoxi, n. sp., 106.

Parasteuhelia hornelli, n. gen. & sp., 106, 110.

,, similis, n. sp., 106.

Ameira minor, n. sp. , 106.

„ tenuipes, n. sp., 106.
Ceylonia aculeata, n. gen. & sp., 109, 110.
Laophonte serrata, 106, 111, 112.
,, inornata, 106, ILL

hirsuta, n. sp., 106, 111, 112.
Laophontella typica, n. gen. & sp., 108.
Cletodes linearis, 5, 106, 111, 112.
Tetragon iceps dubius, n. sp., 106.
,, minor, n. sp., 106.

Dactylophusia tisboides, 5.
latipes, 108.
,, dentata, n. sp., 106.

bavelocki, n. sp., 106.
,, hirsuta, n. sp., 106.

,, ceylonica, n. sp., 106.

,, hamiltoni, n. sp., 106.

,, robusta, n. sp., 106.

,, laticaudata, n. sp., 10(5.

,, semula, n. sp., 106.

,, platysoma, n. sp., 106.

Thalestris mysis, 5, 106.
Pseudothalestris imbricata, 106.
Harpacticus chelifer, 113.
Peltidium ovale, n. sp., 106.

,, angulatum, n. sp., 106.
., speciosum, n. sp., 106.
,, serratum, n. sp., 58.
,, perplexum, n. sp., 106.
Ilyopsyllus affinis, 5, 43, 57, 58.
Porcellidium fimbriatum, 106, 111.

,, brevicaudatum, n. sp., 106, 111.

acuticaudatum, n. sp., 106.
,, ravanai, n. sp., 106.

Idya furcata, 1, 3, 5, 6, 7, 40, 41.

,, longicornis, 111.
Pseudanthessius gracilis, 108.

COPEPODA. 239

Pseudanthessius maximus, n. sp., 86.

,, chelifer, n. sp., 108, 111.

,, concinnus, n. sp., 108.

,, liber, 111.

Licliomolgus minor, 5, 109, 111, 113.
gracilis, n. sp., 111.
ieversi, n. sp., 106, 111.
lankensis, n. sp. , 111.
buddhensis, n. sp., 111.
simplex, n. sp., 112.
elegans, n. sp. , 111.
robustus, n. sp. , 111.
gigas, n. sp., 111.
dentipes, n. sp. , 111.
Paralicbomolgus curticaudatus, n. gen. & sp., 111.

,, longicandatns, n. sp., 111.

Hermannella arenicola, 106, 109, 111.
,, robusta, n. sp., 111.

,, serendibica, n. sp., 112.

Hersiliodes leggii, n. sp., 112.

,, tamilensis, n. sp., 106.

,, dubia, n. sp., 5.

Oncea vemista, 1, 2, 3, 4, 7, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 52, 55, 56, 66,
68, 71, 72, 73, 74, 80.
„ media, 1, 2, 3, 6, 7, 12, 13, 14, 17, 19, 20, 21, 79, 114, 115, 116, 118.
,, snbtilis, 1, 3, 4.
„ minuta, 1, 2, 3, 4, 6, 7, 10, 14, 15, 16, 17, 19, 25, 26, 28, 29, 31, 32, 34, 35,

38, 39, 42, 43, 50, 55, 63, 65, 78, 92.
„ mediterranea, 1, 4, 5, 7, 8, 9, 10, 11, 12, 13, L6, IS, 22, 23, 24, 37, 78, 80.
,, notopus, 5.
,, conifera, 13, 15.
Lubbockia squillimana, 6, 8, 10, 28, 32.

Corycseus venustus, 1, 2, 3, 4, 5, 6, 8, 10, 11, 12, 14, 15, 16, 19, 20, 21, 22, 23, 24,

25, 27, 28, 29, 30, 42, 46, 47, 48, 50, 55, 56, 59, 60, 62. 64,
65, 66, 67, 69, 72, 78, 81.
rostratus, 2, 4, 38, 39, 40.
dame, 3, 8, 10, 11, 13, 14, 15, 16, 17, 18, 19, 22, 23, 24, 26, 27, 31, 52,

55, 64, 65, 67.
fnrcifer, 3, 4, 17, 19, 55, 62, 73, 76, 77.
flaccus, 3, 4, 15, 37, 38, 39, 41.

>40 CEYLON PEARL OYSTER REPORT.

Corycfeus elongatus, 3, 7, 8, 22.

speciosus, 4, 5, 8, 9, 10, 11, 13, 14, 15, 1G, 19, 22, 23, 24, 26, 27, 28, 29,

30, 31, 32, 42, 55, 59, 68, 78.
lubbockii, 4, 11, 37, 39, 43, 47, 56, 64.
,, carinatus, 4, 7, 19, 22, 59.

ovalis, 4, 10, 11, 13, 14, 1G, 21, 23, 24, 2G, 29.

obtusus, 5, 8, 9, 10, 11, 13, 14, 15, 18, 19, 21, 22, 23, 24, 26, 27, 28, 30,
32, 38, 42, 43, 45, 4G, 47, 48, 50, 51, 52, 53, 55, 56, 57, 58,
59, 60, Gl, 64, G5, G6, G7, 68, 72, 73, 78, 79, 80, 114, 115,
118, 121.
gibbulus, 6, 7, 8, 9, 10, 11, 13, 14, 15, 1G, 17, 18, 19, 20, 22, 23, 24, 25,
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 43, 52, 55, 5G. 57, 65,
69, 70, 71. 72, 78, 80. 81.
longistilis, 7, 8, 11, 12, 13, 14, 15, 1G, 17, 18, 19, 20, 21, 22, 23, 69.
concinnus, 13, 15, 1G, 17, 18, 20, 22, 25, 26, 27, 28, 29, 30, 52, 55, 59,

71. 72.
gracilicaudatus, 13, 14, 15, 18, 19, 21, 22. 25, 26, 27, 28, 29, 32, 33, 34,
52, 58, 71, 73.
. ,, robustus, 15.

,, tenuis, 15, 42, 65.

,, longicaudis, 78.

Copilia mirabilis, 7, 8, 9, 10, 15, 16, 17, 19, 20, 25, 94.
Sappbirina ovatolanceolata, 3, 4, 8, 9, 10, 13, 14, 15, 17, 19, 20, 29, 117.
,, gastrica, 9, 11.

,, ovalis, 12, 67.

„ nigromaculata, 14, 15, 21, 22, 23, 29, 59, 115

metallina, 17.
salpa?, 18, 101.
,, auronitens, 21.

,, bicuspidata, 23.

,, intestinata, 25.

„ sinuicauda, 74.

Asterocheres stimulans, 111, 112.
,, dentatus, 111, 112.

,, minutus, 111, 112.

,, manaarensis, n. sp., 112.

,, major, n. sp., 110.

„ minor, n. sp., 112.

Asteropontius typicus, n. gen. & sp., 112.

,, attenuates, n. sp., 111.

C/ollocberes giesbrecbti, n. sp., 111.

> Fish Parasites.

COPEPODA.

Scottocheres elongatus, 111.

,, longifurca, 111.

Lepeopsyllus typicus, n. gen. & sp., 106.

,, ovalis, n. sp., 111.

Doropontius denticornis, n. gen. & sp., 111.
( 'letopontius serratus, n. gen. & sp., 111.
Stephopontius typicus, n. gen. & sp., 111.
Bradypontius siphonatus, 111.
Artotroous orbicularis. 111.
Bomolochus scomberesocis.

,, unicirrus.

( aligns dakari.
,, diaphanus.
,, benedeni.
Lepeophtheirus thompsoni.
Chondracanthus cornutus.

cynoglottidis, n. sp
Brachiella thynni.

,, merluccii.

Anchorella uncinata.

COPEPODA.

Family: CALANID^.

Calanus helgolandicus (Claus).

One of the commonest northern species. Taken at 6 stations in this collection, but
not further south than the Mediterranean.

Calanus gracilis, Dana.

Less common than the preceding species, occurring at 4 stations, but similar in
distribution.

Calanus minor (Glaus).

Common throughout the route traversed, from the Mediterranean to the Indian
Ocean, occurring at 33 stations.

Calanus pauper, Giesbr.

Taken at 58 stations ; distribution similar to that of the last species.

Calanus darwini (Lubbock).

Less plentiful than the two preceding species, occurring at '11 stations, from the
Bed Sea southwards through the Indian Ocean.

2 I

242 CEYLON PEARL OYSTER REPORT.

Calanus vulgaris (Dana).

The most generally distributed of any species throughout the route traversed,
occurring at 70 stations, from the Red Sea southwards.

Calanus robustior, Giesbr.

Only once taken, at Station 21, off Minikoi. in the Indian Ocean; previously
known from the Atlantic and Pacific Oceans.

Eucalanus attenuatus (Dana).

Occurred plentifully at 18 stations, from the lied Sea southwards through the
Indian Ocean to Ceylon.

Eucalanus pileatus, Giesbr.

Taken at 4 stations only, twice in the Red Sea and twice in the Indian ( )cean,
which adds to its hitherto known distribution in the Atlantic and Pacific.

Eucalanus crassus, Giesbk.
Occurred once in the Red Sea and at 4 stations round Ceylon ; previously reported
from the Indian Ocean.

Eucalanus subcrassus, Giesbr.
Occurred at 27 stations; twice in the Red Sea, and throughout the Indian Ocean.

Eucalanus subtenuis, Giesbr.
A few specimens were found from [) stations, all in the sea round Ceylon.

Eucalanus monachus, Giesbr.
A rare species hitherto known only from the Mediterranean. Specimens were
found, off Ceylon, at 2 stations, thus extending its known range to the Indian
Ocean.

Khiucalanus cornutus (Dana).

Reported from 10 stations, all in the Indian Ocean. Previously known from the
Mediterranean, the Atlantic, and the Pacific.

Rhincalanus nasutus, Giesbr.
Similar in distribution to the last species. Occurred at 8 stations in the collection.

Mecynocera clausi, I. C. Thompson.

Found at 27 stations, extending from the Red Sea throughout the Indian Ocean,
the latter being an addition to its hitherto known distribution.

COPEPODA. 243

Paracalanus parvus (Glaus).

One of the most widely distributed species throughout the regions traversed.
Occurred at 65 statious, extending from the British coasts to the ( !eylon pearl hanks.

Paracalanus crassirostris, F. Dahl.

Found at 16 stations, all in the sea round Ceylon ; not previously known from the
Indian Ocean.

Metacalanus aurivillii, Gleve — Plate II., figs. 18 to 20.

Occurred at 27 stations, all in the sea round Ceylon ; previously known only from
the Malay Archipelago. We show the female abdomen and the male and female
fifth natatory legs of this species, as they are not represented in sufficient detail by

( 'LEVE.

Acrocalanus gibber, Giesbr.
Found sparingly at 4 stations, from the Gulf of Suez and Indian Ocean.

Acrocalanus longicornis, Giesbr.

A much commoner species than the preceding, occurred at 33 stations, extending
from the Red Sea throughout the Indian Ocean and around Ceylon.

Acrocalanus gracilis, Giesbr.

Occurred at 9 stations ; general distribution similar to that of the two preceding
species.

Acrocalanus monachus, Giesbr.
A few specimens of this rarer form were found at 2 stations between Minikoi and
Sokotra. Previously known from the Pacific and Indian Oceans.

Calocalanus pavo (Dana).

This beautiful species, easily recognised by its elegant plumose furcal setae,
although rarely found perfect, has a wide range throughout the Atlantic, Pacific and
Indian Oceans, and occurred at 33 stations, extending from Gibraltar through the
Mediterranean, Red Sea, Indian Ocean, and around ( 'eylon.

Calocalanus plumulosus (Glaus).

Similar in distribution to the last species, but less common. It occurred at
12 stations.

Clausocalanus furcatus (Brady).

Well distributed throughout the entire traverse, occurring at 47 stations.

2 i 2

244 CEYLON PEAEL OYSTER REPORT.

Clausocalanus arcuicornis (Dana).
Rarer than the preceding species, hut similarly distributed. It occurred at
20 stations.

Pseudocalanus elongatus (Boeck).
One of the commonest British species ; occurred at 6 stations, extending as far
south as the Gulf of Suez.

iEtideus armatus, Beady.
A species widely distributed throughout the Atlantic, Pacific and Indian Oceans,
hut only taken at 3 stations in this collection, from the Mediterranean to the Gulf
of Suez.

Undeuchaeta minor, Giesbr.
Occurred off Gibraltar, and at 2 stations in the Indian Ocean ; the latter are
additions to its hitherto known range.

Euchirella rostrata (Claus).
Occurred twice in the Indian Ocean.

Euchirella messinensis (Claus).
. Only once taken, off Minikoi, west of Ceylon, thus considerably extending its
southern range; the Mediterranean and the Gulf of Gascony being the only
previous records.

Euchaeta marina (Pbestand.).

A common ocean species; occurred at 36 stations, extending throughout the
entire traverse.

Euchata spinosa, Giesbr.
Found very sparingly off Gibraltar and in the Mediterranean, and again oil'
Ceylon ; not previously reported from the Indian Ocean.

Euchaeta acuta, Giesbr.
Taken at 2 Mediterranean stations, between Messina and Port Said.

Euchaeta concinna, Dana.
Occurred at 3 stations in the Bed Sea and at 4 stations round Ceylon.

Euchaeta barbata, Brady.
Occurred at 2 stations in the Indian Ocean near Ceylon. Known previously only
from the Atlantic.

COPEPODA. 245

Scolecithrix danae (Lubbock).
Taken at 18 stations in the Indian Ocean and round Ceylon.

Scolecithrix brady£ Giesbr.
Occurred once in the Mediterranean, and at G stations in the Indian Ocean, the
latter being an addition to its known range.

Scolecithrix chelipes, Gjksbr.
Taken only at one station, in the Red Sea, its only known habitat.

Scolecithrix auropecten, Oiesbr.
A rare species — was found in the Red Sea, an addition to its known range in the
Mediterranean and Atlantic.

Scolecithrix tenuipes, T. Scott.
Like the preceding species, this was found in the Red Sea, its only previously
known habitat being the Gulf of Guinea.

Ridgewayia, n. gen.

Body cyclopoid in form, G eephalothoracic segments well defined. Abdomen 4-jointed,
anterior antennte 25-jointed. Posterior antennae 2-branched, the outer branch
consisting of 2 joints, the inner branch of many joints and longer than the outer.
Monti i organs very similar to those of Calanus and Temora.

Outer and inner branches of 1st to 4th natatory legs all 3-jointed. Outer branch
of 5th pair 3-jointed : inner branch 2-jointed.

The male of the one species occupying this genus being unknown, it is not easy to
fix with certainty the exact systematic position. In the anterior and posterior
antenna?, as well as in the mouth organs of the female, it closely resembles the
( 'alaninte. In the segmentation of the first 4 pairs of natatory legs it agrees with
Calanus, but not in the 5th pair. On the whole we think that the position of the
genus should be amongst the Calanida?. At the suggestion of Professor Herdman
we have named this genus in honour of Sir West Ridgewav. who was Governor oi
Ceylon when the pearl oyster investigation was carried on.

Ridgewayia typica, n. sp. — Plate I., figs. I to L3.

Length, female 0'85 millim. ; male unknown.

Cephalothorax G-jointed, the cephalic segment equal in length to the four following
combined. The 5th thoracic segment has a strong hook pointing downwards on its
ventral surface. Rostrum short, broad and pointed. Abdomen 4-jointed, the genital
segment very wide and ecpial in length to the following two united ; it bears a similar
hook to that of the last thoracic segment on its right side posteriorly. Furcal rami
about twice as long as broad, each bearing 4 long terminal setae.

•24(5 CEYLON PEARL OYSTER REPORT.

Anterior antennas 25-jointed, nearly equalling in length the cephalothorax. The
proportional lengths of the joints are as follows : —

1. 2. 3. 4. 5. G. 7. 8. 9. 10. 11. 12. 13. 14.J5. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
15. 20. 7. 7. 7. 7. 7. 7. 7. 7. 7. 7. 8. 8. 8. 9. 8. 8. 8.' 7. 7. 11. 17. 21. 20.

Posterior antennas 2-branched, the outer branch consisting of 2 joints, the inner
of 8, the 2 basal and the apical joints being each about double the length of the
intermediate ones. Mandible broad with 9 or 10 small teeth, palp 2-branched, one
branch having 2, the other 4 joints. Maxilla well developed, inner branch composed
of 2 large setiferous digits. First and second maxillipeds similar to those of the
Calanidse.

Natatory legs 1 to 4 with outer and inner branches all 3-jointed, the lateral and
terminal spines destitute of serrations and hairs. The inner branch of 5th pair is
2-jointed ; the outer branch 3-jointed, bearing lanceolate spines with serrated edges ;
the 3rd joint is attached to the centre of the 2nd joint.

Two specimens, both females, were found in the Muttuvaratu pearl-oyster washings.

This, the only known representative of the genus Iiidgewayia, is easily recognised
by the inner branch of the posterior antennas, by the hooks on the last thoracic and
genital segments, and by the 5th pair of natatory legs.

Phaenna spinifera, Claus.
Occurred at 3 stations, near Gibraltar, in the Red Sea, and in the Indian Ocean.

Famu.y : CENTKOPAGID^E.

Centropages chierchiae, Giesbr.

Occurred at 5 stations, near Gibraltar, in the Indian Ocean, and about the Cheval
Paar and other pearl banks, ( leylon. Not previously reported from the Indian Ocean.

Centropages typicus, Kroyer.

A well-known northern species, common around the British coasts. Occurred at
3 stations in the Mediterranean.

Centropages violaceus, Glaus.
Found at 11 stations, extending from the Mediterranean to the lied Sea, and
throughout the Indian Ocean.

Centropages furcatus (Dana).

One of the commoner species of this genus. Occurred at 29 stations, from the lied
Sea throughout the Indian Ocean.

Centropages elongatus, Giesbr.
Found at 8 stations, from the Gulf of Suez throughout the Indian Ocean.

COPEPODA. 247

Centropages gracilis (Dana).

Occurred at 14 stations, the range being much the same as that of the preceding
species.

Centropages kroyeri, Giesbr.

Found twice in the northern Indian Ocean, in the vicinity of Socotra. The
western Mediterranean appears to he its only previously known habitat.

Centropages calaninus (Dana).
Occurred at 1 1 stations in the Indian Ocean.

Centropages orsini, Giesbr.
This, like the preceding species, occurs at 11 stations, all in the Indian Ocean.

Centropages tenuiremis. n. sp. — Plate I., tigs. 14 to 18.

Length, female 2'0 millims. ; male 1*8 millims.

Body somewhat angular, widest anteriorly, slightly tapering to last segment of
thorax, which is terminated by long outwardly extended lateral acute projections.
Anterior antennas of female 24-jointed, the proportional lengths being as follows : —
1. 2. 3. 4. 5. G. 7. 8. 9. LP. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
3. 4. 2. -2. 3. 3. 2. 3. 3. 4. 4. 5. 6. 7. 8. 8. 8. 8. 7. 5. 5. 5. 5. 5.

Male right antenna 24-jointed; joints 13 to 17 are considerably thickened: a
geniculation occurs between the 18th and 19th joints.

Abdomen of female 4-jointed. of male 5-jointed, the last one very small.

Furcal ramus sub-linear, the length about three times the width. Terminal caudal
setae in the female have the basal portion thickened.

The basal joint of the right 5th natatory leg in the female is acutely produced on
the inner side and bears three rows of minute teeth. The 5th legs in the male are in
general similar to those of C. typicus, as are the other appendages not alluded to.

Large numbers of specimens, both male and female, were found at 21 stations
round Ceylon.

The acute lateral terminal thoracic spines, the 5th natatory legs in the female, and
the abdomen and furcal rami are the distinguishing features of this species.

Centropages dorsispinatus, n. sp. — Plate I., figs. 19 to 25.

Length, female 1'37 millims. ; male 1*24 millims.

Cephalothorax ovate, the posterior segment having a rounded acute terminal

projection. Rostrum short, broad and triangular. A remarkable curved beak-like

hook adorns the median dorsal line of the posterior edge of the cephalic segment.

Anterior antennas of the female 24-jointed, the proportional lengths being as follows :—

1. 2. 3. 4. 5 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

3. 5. 1. 1. 1. 1. 1. 1. 2. 2. 3. 3. 5. 5. 5. 6. 6. 6. 6. 5. 4. 3. 3. 4.

248 CEYLON PEARL OYSTER REPORT.

The 2nd, 5th, 10th and 11th joints bear spinous projections. Male right anterior
antennas 23-jointed, with a geniculation between the 18th and 19th joints.

Abdomen of female 4-jointed ; of male 5-jointed, the last joint very small. Furcal
rami slightly curved inwards, about twice as long as the width. Fifth natatory
legs attenuated ; the second joint of right leg- in female has a long plain projecting
spine on inner side. The chela of the male right natatory leg is clothed with short
hair on the outer side.

The other appendages are similar to those of < '. typicus. A number of specimens,
male and female, were taken in Palk Straits, Ceylon.

The species is easily distinguished by the median dorsal cephalic hook, and by the
5th pair of natatory legs and the abdomen and furcal rami.

Isias clavipes, Boeck.

This British species was only taken once, in the first gathering. It ranges to the
Mediterranean and Atlantic Ocean.

Pseudodiaptomus salinus, Giesbr. — Plate II, figs. 21 to 23.

Occurred at 3 stations in the Gulf of Suez and at 3 stations in the Indian Ocean,
its only previous record being from the Red Sea.

Giesbrecht's specimen was a female, the male remaining unknown until now ; we
have the satisfaction to record it from the same stations at which the females were
found. The male measures 1'25 millims., and its characters are shown by figs. 22
and 23, on Plate II. The female also measures 1"25 millims., and its fifth pair of legs
are shown at fig. 21, Plate II.

Pseudodiaptomus serricaudatus (T. Scott).
Occurred at 20 stations throughout the Indian Ocean and about Ceylon.

Pseudodiaptomus aurivillii, Cleve — Plate II., figs. 24 to 26.

Found at 8 stations in the Indian Ocean. Fortunately the specimens include the
male hitherto unknown. The female measures 1'2 millims. and the male "93 millim.
The characteristic appendages of both sexes are shown by figs. 24 to 26, on Plate II.

Temoropia mayumbsensis, T. Scott.

Two records for this rare species were added in the Gulf of Suez. The Gulf of
Guinea is its only previously known habitat.

Temora longicornis (Muller).
This common British species was found at 2 stations, from the English Channel
to the Mediterranean.

Temora discaudata, Giesbr.
One of the most widely distributed species throughout the regions traversed.

(JOPKPOD.A. 249

Occurred at 60 stations, from the Mediterranean southwards, throughout the Indian
Ocean, and round Ceylon.

Temora stylifera (Dana).

Occurred at 16 stations, from the Red Sea southwards, through the Indian Ocean,
and ahout Ceylon.

Temora turbinata (Dana).

Occurred first in the Gulf of Manaar, and at 4 other stations ahout the Ceylon Pearl
Banks. Has been previously reported from the Pacific, New Zealand, and the Gulf
of Guinea, hut not from the Indian Ocean.

Metridia lucens, Boeck.

Fairly common, from the English Channel, through the Mediterranean, and as far
as the Gulf of Suez, hut not further south.

Both the latter localities are an extension of its known range of distribution.

Pleuromamma gracilis, Claus.

Occurred at 24 stations, from the English Channel onwards to the Indian Ocean,
and in the open sea around Ceylon.

Pleuromamma xiphias, Giesbr.

This was taken in the first gathering only, probably near Gibraltar.

Its previously known range includes the Atlantic, Pacific and Indian Oceans.

Pleuromamma abdominalis (Lubbock).

Found at 28 stations, from the Mediterranean to the Indian Ocean, as far as
Ceylon.

Lucicutia flavicornis (Claus).

Occurred at 21 stations, extending from the English Channel to the Indian Ocean,
as far as Ceylon.

Heterorhabdus spinifrons (Claus).

Found once in the Mediterranean and again at 4 stations in the Indian Ocean and
twice off Minikoi, near Ceylon.

Heterorhabdus papilliger (Claus).

Heterorhabdus abyssalis (Giesbr.).

Heterorhabdus clausi (Giesbr.).

The above three species were each taken once only. The two former between
Perim and 200 miles into the Indian Ocean — the latter near Minikoi. Each record
is an addition to the known distribution of the species.

2 K

250 CEYLON PEARL (JYSTER REPORT.

Family : PSEU] >< »< !Y< !LOPIDvE.

Pseudocy clops obtusatus, Brady and Robertson.

A few specimens only were obtained in the northern Indian Ocean and about the
pearl banks and Cheval Paar, Ceylon.

The British coast appears to be the only previously recorded habitat.

Family : CANDACII1 )M.

Candacia armata (Boeck).
Taken only in the first gathering:, between the English Channel and Gibraltar. Tt
is probable that the tropical records of this species, long known as C. pectinata,
Brady, refer to other Candacias, as more than one species is included in the figures
of C. pectinata in the Keport on the " Challenger" Copepoda, but none of them are
identical with Boeck's C. armata.

Candacia simplex (Giesbr.).
Occurred at 19 stations, from the Mediterranean onwards through the Indian Ocean
and at several of the Ceylon stations. Not before recorded from the Indian Ocean.

Candacia bispinosa (Claus).
Found on three occasions in the Mediterranean and the lied Sea. Previously
reported from the Indian Ocean.

Candacia bradyi, A. Scott.

Occurred at 8 stations, extending from the Gulf of Suez into the Indian Ocean.
Mr. Scott's previous record was from Aden. It is probable that some of the
previous records of C. pectinata from tropical seas are really this species.

Candacia tnxneata (Dana).
Occurred at 18 stations, from the Gulf of Suez onwards through the Indian Ocean
to Ceylon.

Candacia catula (Giesbr.).
Occurred at 17 stations, the range being similar to that of the preceding species.

Candacia longimana (Glaus).
Obtained at 3 stations only, from the south of the Red Sea and from Perim into
the Indian Ocean.

Candacia sethiopica (Dana).
Range of this species is similar to that of C, catxda ; obtained at 17 stations.

COPEPODA. 251

Candacia curta (Dana).
Of similar range to the last species, but less plentiful ; was found at G stations.

Candacia pachydactyla (Dana).
Obtained at 11 Rtations in the Indian Ocean and round Ceylon.

Kamiia : PONTELLIP.E.

Calauopia elliptica (Dana).

Taken between Port Said and Suez and then fairly continuously through the
Indian Ocean and round Ceylon. < (ccurred at 07 stations.

Calanopia minor, A. Scott.
Of similar range to C. elliptica — occurred 25 times.

Calanopia aurivillii, Cleve.

Obtained at 4 stations in the vicinity of Galle and at 4 on the pearl banks.
Cleve's specimens were from the Malay Archipelago.

Labidocera acuta (Dana).
Common from Port Said throughout the Indian Ocean and round Cevlon— occurred
at 39 stations.

Labidocera minuta, Giesbr.

Occurred first at the southern end of the Gulf of Suez and then at 20 stations
throughout the Indian Ocean and round Ceylon.

Labidocera detruncata (Dana).
Occurred at 7 stations in the Indian Ocean, and also found at Back Bay, Trincomalee.

Labidocera pavo, Giesbr.
Obtained at 14 Ceylon stations. Known previously only from the Red Sea.

Labidocera kroyeri (Brady).
Similar in distribution to last species; obtained at 11 Ceylon stations.

Labidocera kroyeri (Brady), var. gallensis. nov. — Plate II., figs. 6, 7.
Male differs from L. kroyeri in several particulars. The posterior thoracic segment
in this variety is rounded at base, and has a trifid projection on the left side instead
of a bifid one as in L. kroyeri. The 1st abdominal segment has a long narrow spine
on its right basal corner. The end of basal portion of the claspers in the 5th natatory
legs is very short and the chela more spinous than that of L. kroyeri. In other
respects there is a close similarity between the species and this variety.
Taken in surface tow-nettings from Galle Harbour and elsewhere, Ceylon.

2 K 3

252 CEYLON PEARL OYSTER REPORT.

Labidocera kroyeri (Brady), var. stylifera, nov. — Plate II., figs. 8, 9.

Male differs from L. kroyeri like the variety gallenus in the last thoracic segment
and in the 5th natatory legs. The basal portion of the latter is produced into a long
rod-like projection. Several specimens were taken at different stations round Ceylon.

Labidocera psctinata, n. sp. — Plate II., figs. 10 to 14.

Length, female, 2'1 millims. Male unknown.

Cephalothorax 5-jointed, robust in centre, slightly tapering towards each end, the
terminal segment having strong lateral spinous projections. Rostrum short, bifid at
apex. Anterior antennae 23-jointed, in length about equal to the cephalothorax.

The relative lengths of the joints are as follows : — ■

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23.
6. 16. 2. 2. 2. 4. 4. G. 5. 5. 8. 10. 10. 12. 1G. 14. 1G. 16. 10. 10. 10. 9. 9.

Posterior antennae and mouth organs and 1st to 4th pairs of natatory legs as in the
other members of this genus. Abdomen 3-jointed, about one-third as long as the
cephalothorax ; the right basal extremity of the genital segment is produced into two
curved spines ; the middle joint bears a knobbed protuberance. The furcal rami
are slightly asymmetrical, the right one being nearly half as large again as the left ;
the inner side of each is lined with fine hairs ; each furca terminating: in five short
setye. Fifth natatory legs, each composed of two 1 -jointed branches, asymmetrical,
the inner branches being differently denticulated ; both branches of the left leg are
larger than those of the right. The characters of the abdomen and 5th natatory legs
are unlike those of any other species known to us.

Four specimens, all females, were taken in Palk Straits, Ceylon.

Pontella fera, Dana.

Found at 3 stations, viz., twice off Minikoi, Indian Ocean, and at Vankali Paar,
Ceylon.

Pontella securifer, Brady.
Taken off Minikoi, Indian Ocean, and at 10 stations round Ceylon.

Pontella princeps, Dana.
Was found once only, at Chilaw Paar, Ceylon.

Pontella tenuiremis, Giesbb.

Was found once only, in Palk Strait, Ceylon. Giesbrecht's specimen was from
the Pacific Ocean.

Pontella danae, var. ceylonica, nov. — Plate II., figs. 1 to 5.

Length, female 3 "4 millims.

Cephalothorax of nearly the same width throughout, in this respect differing from

COPEPODA. 253

P. dance, which tapers gradually from the second to the posterior thoracic segment.
Rostrum nearly straight, length about double the width, and has bifid apex.
Fifth natatory legs asymmetrical, the left having outer and inner branches larger
than the right branches ; the outer one has a large and small spine on the outer side.
First joint of abdomen somewhat globular, whereas that of P. dance is more
quadrate. A number of specimens, all females, were found at 5 stations around
Ceylon. The 5th natatory legs and the shape of the abdomen serve to distinguish
the variety from P. dance, Giesbbecht.

Pontellina plumata, Dana.
Occurred at 17 stations, south of Gull of Suez, in the Indian Ocean, and round
Ceylon.

Pontellopsis armata (Giesbr.).

Occurred first between the Maldives and the Gulf of Manaar, and then at
9 Ceylon stations. Previously known from the Pacific and Indian Oceans.

Pontellopsis krameri (Giesbr.).

Occurred at 4 Red Sea stations. Giesbrecht's specimens were also from the Red
Sea. The species has been recorded from Fortescue Strait by A. Scott,

Pontellopsis regalis, Dana.
The only specimen of this species was taken in the Mediterranean, near Messina.

Pontellopsis strenua (Dana).
Found only at Cheval and Periya paars, Ce)don.

Pontellopsis perspicax (Dana).
Like the last species, this was only taken on the Cheval and Periya paars.

Pontellopsis herdmani, n. sp. — Plate II., figs. 15 to 17.

Length, female 1*9 millims. ; male unknown.

Cephalothorax about twice as long as its breadth, having 5 segments, the posterior

segment terminating on each side with a triangular acuminated spine. Rostrum long,

narrow, and bifid. Anterior antennas 16-jointed, the relative lengths of the joints

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
beins; as follows : -

& 6. 7. 5. 8. 3. 5. 3. 5. 5. 6. 9. 6. 0. 7. 6. G.

Posterior antennae, mouth organs and 1 to 4 pairs of natatory legs as in the other

species of Pontellopsis. Abdomen about half the length of the cephalothorax,

composed of 2 joints, the first being about double the size of the second and having

2 thorn-like projections on the right side. Furcal rami twice as long as broad, with

fine hairs on the inner surface and each terminating in 5 short non-plumose seta'.

254 CEYLON PEARL OYSTER REPORT.

Fifth pair of natatory legs each 2-branched ; each branch composed of one bifid
joint, the outer branches each having 3 small spines on outer edge. A few
females were found in Galle Harbour and also off Karativo Island in the Gulf of
Manaar.

The abdomen and 5th natatory legs distinguish this from any other described form.
We have peculiar pleasure in naming it after Professor Heedman.

Acartia clausi, Giesbr.

A common British species. Occurred at the first 4 stations as far as the Gulf of
Suez, and once off Ceylon at the south end of the Cheval Paar.

Acartia longiremis, Lillj.
Taken at 9 stations, from the English Channel to the Mediterranean oft' Messina.

Acartia dubia, T. Scott.
Found in the Suez Canal and in the Red Sea.

Acartia erythraa, Giesbr.
Well distributed throughout the traverse, occurring at 53 stations, from the Gulf
of Suez, throughout the Indian Ocean, and around Ceylon.

Acartia centrura, Giesbr.
Occurred in Gulf of Suez and the Red Sea, and at 6 stations round Ceylon.
Previously reported from the Red Sea and Atlantic Ocean.

Acartia negligens, Dana.
Obtained at 38 stations, from Gulf of Suez onwards through the Indian Ocean, and
common around Ceylon.

Tortanus gracilis (Brady).
One record only from about the Gulf of Suez. Brady records the species from the
Philippine Islands.

Tortanus forcipatus (Giesbr.).
Occurred at 3 Ceylon stations only, viz., off Kalpentyn Island, Cheval and Periva
paars, and off Pantura, south of Colombo. Giesbbecht's specimens were from Amoy,
China.

Family : CYCLOPID.E.
Thorellia brunnea, Boeck.
Found in washings from sponges, Gulf of Manaar,

COPEPODA. 255

Oithoua plumifera, Baird.

A common species, recorded from 40 stations almost continuously throughout the
seas traversed.

Oithona similis, Clai s.

Commencing at the Gulf of Suez, this species occurred at 38 stations; similar in
distribution to 0. plumifera.

Oithona minuta, T. Scott.

This species, first recorded from the Gulf of Guinea, appears to be abundant
throughout the Indian Ocean and round Ceylon, occurring at 35 stations.

Oithona rigida, Giesbr.

Occurred in the Red Sea, about Minikoi, and at 18 stations around Ceylon.

Oithona spinifrons, Boeck.

This common British species, closely allied to 0. similis, occurred in the earlier
gatherings, and in the Red Sea and Northern Indian Ocean, to Ceylon.

Oithona nana, Giesbr.
Occurred at 3 stations on the Pearl banks, Ceylon.

Oithona setigera, Dana.
Taken on 4 occasions in the Mediterranean and once in the Suez Canal.

Family : ASCIDICOLID JE.

Doropygus normani, Bkady.

A few specimens were taken from the branchial sac of a species of Cynthia found
at the Aripu reef, Gulf of Manaar.

Doropygus pulex, Thorell.

Found attached to the branchial sac of a species of Molgulct, from the Cheval and
Periya paars, Ceylon.

Botryllophilus ruber, Hesse.
Fouud in washings from sponges, Gulf of Manaar.

Family : HAEPACTICID.E.
Sunaristes paguri, Hesse.
A few specimens were found in the general washings from < leylon In vertebrates.

256 CEYLON PEARL OYSTER REPORT.

Sunaristes inopinata, n. sp. — Plate III., figs. 1 to 8.

Length, male 1"3 millims. ; female 1*5 millims.

Body resembling S. paguri, but all the segments broader in proportion to length.
Anterior antennas of female 6-jointed, densely covered on the upper side with
plumose setae and bearing two long club-like appendages, possibly olfactory.

The relative lengths of the ioints are as follows : — ' ' ' — '- — -r
to J 11. 7. 7. 5. 4. 15.

Anterior antennae of male short and broad, terminating in a curved hook,

Posterior antennae and mouth organs as in & paguri. Both branches of 1st to 4th

pairs of natatory legs 3-jointed, most of the joints having small bundles of fine hairs

on the surface or at the sides. Fifth pair as in S. paguri.

Abdomen about the same length as the cephalothorax, composed of joints of which

the genital segment is the larger one. Furcal rami twice as long as the breadth,

tapering to the apex, and each having a stout spine on inner margin. Several

specimens were found in the general washings from Ceylon Invertebrates.

Sunaristes longipes, a. sp. — Plate III., figs. (J to 11.

Length, female 1'5 millims. ; male unknown.

Similar in build to the last species but more robust. Anterior antennae 6-jointed
and similar to <S. inopinata, except in proportional lengths of joints, which are as

follows : — '—^ — '- — - — —

15. 7. 3. 5. 3. VJ.

Abdomen short and robust, about equal in length to the first 3 thoracic segments.
First 2 joints are coalescent, the 4th aud especially the 5th very small. Furcal
rami long and tapering, the length 3 times that of the breadth ; each has a spine
on both sides. Mouth organs as in Longipedia, Ganuella and Suncuvites. Other
organs as in last species, with the exception of 4th pair of natatory legs, which (fig. 10)
are very narrow, the inner branch being nearly double the length of the outer one.

The length of the furcal rami and the elongated 4th pair of natatory legs serve to
distinguish this species from others of the genus. One specimen only, a female, was
found in the general washings from Ceylon Invertebrates.

Sunaristes curticaudata, n. sp. — Plate III., figs. 12 to 17.

Length, female, 1*6 millims. Male unknown.

First segment of cephalothorax equal in length to that of the four following
segments combined, and much broader. Abdomen 4-jointed, about three-fourths of
the length of the cephalothorax. Anterior antennae 4-jointed, all adorned with
plumose setae, the second joint having also two spines. The proportionate lengths

1. 2. 3. 4.

are as follows : —

12. 16. 5. 7.

Mouth organs as in Longipedia, Canuella and Sunaristes.

COPEPODA. 257

Other organs similar to those of S. pagm%, with the exception of the inner
branch of the 4th natatory legs, which in this sjsecies is 2-jointed (rig. 16). Caudal
segments short, their length not much exceeding the width ; the anterior inner
corner of each is marked off by a dividing line. One specimen only was found in the
general washings of Ceylon Invertebrates.

The form of the furcal rami is sufHcientlv diagnostic to distinguish this from
other species of the genus. The fact that this species has the inner branch of the
fourth pair of legs only 2-jointed may, sometime, necessitate its removal to a new
genus.

Longipedia coronata, Claus.

Occurred at 2 stations in the Mediterranean and once in the Siiez Canal. Usually
a littoral species. Found also in washings from Sponges, Gulf of Manaar.

Longipedia minor, T. Scott.
A few specimens of this form were obtained in the tow-net off Marichchukaddy.

Canuella perplexa, T. and A. Scott.
One specimen was taken between Port Said and Suez.

Ectinosoma atlanticum (Brady and Robertson).

The most abundant species throughout the collection. Occurred at 6G stations, from
the Mediterranean throughout the Red Sea and Indian Ocean and all around Ceylon.

Ectinosoma roseum, Dana.
Hardly less common than E. atlanticum. Fifty-nine stations, similarly distributed.

Ectinosoma normani, T. and A. Scott.

Ectinosoma propinquum, T. and A. Scott.

Both species found in washings from young pearl oysters and in the general
washings from Ceylon Invertebrates.

Setella gracilis, Dana.
Occurred at 44 stations fairly continuously, from the Mediterranean to Ceylon.

Miracia efferata, Dana.

Was obtained in the Indian Ocean, twice off Minikoi, and between the Maldives
and the Gulf of Manaar.

Miracia minor, T. Scott.
Was taken off Gibraltar, and was also found at 2 stations in the northern Indian
Ocean. Scott's specimens were taken in the Gulf of Guinea.

•1 L

258 CEYLON PEARL OYSTER REPORT.

Euterpina acutifrons (Dana).

Well distributed throughout the traverse, occurring at 48 stations, from the
Mediterranean to Ceylon.

Tachidius littoralis, Poppe.
One specimen was taken in the Gulf of Suez.

Clytenmestra scutellata, Dana.

Occurred at 10 Indian Ocean stations, and 3 round Ceylon, viz., off Pautura to
the south of Colombo, at Cheval Paar and west of Periya Paar, Gulf of Manaar.

Clytenmestra rostrata (Brady).

Found at 8 stations, from the Mediterranean, Gulf of Suez, Bed Sea, and the
Indian Ocean, and once at Ceylon, near the Muttuvaratu Paar.

Tegastes sphaerica (Claus).
One specimen of this littoral species was taken between Port Said and Suez.

Tegastes nigrans (T. and A. Scott).
A number of specimens were found in washings from Muttuvaratu pearl oysters.

Tegastes imthurni, n. sp. — Plate IV., figs. 1 to 9.

Length, female 0"6 millim. to 0'45 millim. ; male unknown.

Cephalothorax composed of 6 segments; the first broadly falciform, and extending
ventrally to double the width of the other segments.

Abdomen 4-jointed, the first extending ventrally into a long jjrojection, truncated
at end. A large rounded hook from the centre of the 1st segment projects over the
posterior ends of the other segments.

, . , , , . 1. 2. 3. 4. 5. 6.

Anterior antennas G-iomted, the relative lengths being : -

J ^ & 25. 18. 9. 4. 4. 4.

Posterior antennas and mouth organs, with the exception of the 2nd maxillipeds,
as in T. sphcerica. In this species the inner concave edge of the chelate hand, instead
of being pectinated, has a small funnel-shaped expansion, the upper circular edge
being clothed with fine hairs. The inner projecting corner of the hand lias, on the
upper edge, about 10 short spines arranged in a pectinate manner.

The 1st pair of natatory legs are similar to T. sphcerica. The 2nd, 3rd, and
4th pairs differ considerably from that species, however, and also from the generic
description in Brady's Monograph of British Copepoda. In the 2nd and 3rd pairs of
T. imthurni, and also in T. doimani, and in T. twynami, the inner branches are
composed of 3 joints, while the outer branches have only 2 joints. The 4th pair has
the outer branch 3-jointed, and has only 2 joints in the inner branch. The basal
joint of the inner branch of this pair is a wide foliaceous expansion with thickened

COPLTODA. 259

edges. The 5th pair in this and the following 3 species are also different from the type

of the genus, and instead of being 2-jointed, are composed of 1 joint only, which,
however, is obviously built up of 2 coalesced joints. Fig. 2 represents a smaller form,
not differing in details of structure, except in the absence of hook from abdomen.

Several specimens were found in the washings from the Muttuvaratu pearl oysters.

At Professor Herdman's suggestion we dedicate this new species to Mr. E. F.
IM ThuKN, the Lieutenant-Governor of Ceylon at the time of the investigations.

Tegastes donnani, n. sp. — Plate IV"., figs. 10 to 12.

Length, female, G"37 millim. ; male unknown.

In appearance and structure this species very nearly resembles T. imthurni, the
7-jointed anterior antennae and the oth natatory legs being the only important points

of difference.

, . . 1. 2. 3. 4. 5. 6. 7.

Proportionate lengths of antennary joints : - — _

Four specimens, all females, were found in the Muttuvaratu pearl oyster washings.
We name this species after Captain J. DONNAN, C.M.G.. formerly Inspector of the
Ceylon Pearl Fisheries.

Tegastes twynami, n. sp. — Plate IV., figs. 13 to Hi.

Length, female 0'54 millim. ; male unknown.

This species also resembles T. imthurni in detail, with the exception of the anterior
antemne, the hand of the 2nd maxillipeds, and the 5th natatory legs. The anterior
antenna? are only 6-jointed, the proportionate lengths of the joints being as

1. 2. 3. 4. 5. (5.

follows : —

13. 13. 10. 8. 5. 5.

The inner concave edge of the hand in 2nd maxilliped is strongly pectinated and
has a round funnel-shaped protuberance with ciliated edge similar to that of
T. imthurni; the terminal falcate claw is very stout. Fifth pair of natatory legs like
those of T. dormant, but larger. Two specimens, both females, were found in the
washings from the Muttuvaratu pearl oysters.

The cuticle in the foregoing species is covered with minute circular dots, these are
also found on the basal joint of the fourth pair of legs, on the fifth pair and in a lesser
degree on the chela of the posterior maxillipeds.

We name this species in honour of Sir William Twynam, who has long been
connected with the Ceylon Pearl Fisheries.

Tegastes chalmersi, n. sp. — Plate IV., figs. 17 to 22.

Length, female, 0'3 millim. ; male unknown.

A much smaller form than any of the three preceding. Cephalothorax 5-jointed ;
length and breadth of 1st joint about equal.

2 L 2

260 CEYLON PEARL OYSTER REPORT.

Abdomen 3-jointed, the 1st joint being produced as in the other species of the

genus, but different from them in having 4 large denticulations on its outer surface.

Anterior antennae 7-jointed, the proportionate lengths of the joints being as

1. 2. 3. 4. 5. 6. 7.

lollows :

14. 10. G. 4. 4. 4. 5.

The 2nd maxillipeds differ considerably from those of any of the preceding species.
The middle joint is long and narrow, arcuate on one side and flat on the other, with
short setae on one-half of the flat side. The terminal spine is shaped like a scythe
and about f the length of the middle joint. Natatory legs as in T. imthurni,
excepting 4th and 5th pairs. In the 4th pair the outer and inner branches are both
3-jointed, and the basal joint of the inner branch is not foliaceous. The 5th legs are
less angular than those of the other species, the surface being covered with rows of
convolute markings.

Two specimens, both females, were found in the Muttuvaratu pearl oyster
washings. The anterior antennae, the 2nd maxillipeds, and the 4th natatory legs
readily distinguish this species from the others of the genus.

This species is named after Dr. A. J. Chalmers, formerly a Liverpool Student of
Science, now Registrar and Professor in the Medical College, Colombo.

Stenhelia brevicornis, n. sp.— Plate V. figs. 1 to {J.

Length, female, 0"9 nhllim. : male unknown.

Cephalotliorax narrow, 5-jointed. Anterior antennae short, 8-jointed, the relative

lengths of the joints being as follows : Most of the joints

° J & 18. 12. 10. 8. 3. 4. G. 12. J

are shorter than the breadth and bear numerous setae. The 4th joint is produced on

upper side, terminating in a long filament.

Posterior antennae, mouth organs, and 1st to 4th pairs of natatory legs as in *S'. ima.
The basal joint of 5th pair is large and triangular, bearing G marginal and apical
setae, two of them plumose ; second joint long and narrow, tapering towards apex and
bearing six setae, the apical one much longer than the marginal ones. Abdomen
5-jointed; the posterior margin of the 1st joint has a dorsal hook, the margins of the
other joints being fringed with fine hairs. Furcal rami about ;! times as long as
broad.

Two specimens only, both females, were found in the Muttuvaratu pearl oyster
washings. The short, broad-jointed anterior antennae, the outer joint of the
5th natatory legs, and the long furcal rami are the chief distinguishing features oi
this species.

Stenhelia gracilicaudata, n. sp. — Plate V., figs. 10 to 15.

Length, female, 0'G7 millim. ; male unknown.

Cephalotliorax 5-jointed, very robust. Anterior antennae 8-jointed, the proper-

GOPEPODA. '2(51

. . . . „ 1. 2. 3. 4. 5. G. 7. 8. _,.

tional lengths of the joints being as follows: -— — - 1 hey are

14. _jU. 1U. LI. 4. 0. -J. lu.

well clothed with setae on the upper side. The 4th joint is produced and terminates
in a long narrow filament.

Posterior antenna? and mouth organs as in S. brevicornis. Natatory legs in general
similar to those of S. brevicornis, but the 1st pair diners therefrom in the respective
lengths of its joints ; the 5th pair is less triangular, the second joint being ovate.
Abdomen 5-jointed, about the same length as the cephalothorax, but only half the
width, and non-setiferous on posterior edges. Furcal rami about 4 times as long as
broad.

One specimen only, a female, was found in the Muttuvaratu pearl oyster washings.

The chief distinguishing features are the anterior antennae, the 1st and 5th natatory
legs, and the long narrow furcal rami.

Stenhelia longicornis, n. sp. — Plate V., figs. 16 to 22.

Length, female, 0-8 millini. ; male, 0"6 millim.

Cephalothorax similar to that of S. brevicornis. Anterior antennae 8-jointed, long

and narrow, the proportional lengths being : * „ . ., _, ., .. „ . — r— ^T The ^th joint
11 la. 24. 12. 11. 3. 4. 5. /.

terminates in a long narrow filament ; the seta? of the various joints as in

S. gracilicaudata.

Posterior antennae and mouth organs and 2nd to 4th pairs of natatory legs as in
S. brevicornis. The 1st pair of legs agrees in form with S. gracilicaudata, as also
does the 5th pair in the female, with the exception of the spines of the inner joint,
which in this species are shorter, more numerous, and mostly plumose. The outer
joint has a pellucid circle near the outer edge. Fig. 21 shows the inner branch of the
2nd pair in the male, and fig. 22 the 5th leg of the male, which is much smaller
than that of the female.

Abdomen short and broad, the 4th joint having a short tooth on lower edge. The
furcal rami are very small, about half as long as broad. A few specimens of each
sex were found in the Muttuvaratu pearl oyster washings. The long narrow anterior
antennae, the 5th natatory legs, and the small furcal rami are the distinguishing
characters of this species.

Stenhelia perplexa, n. sp. — Plate VI., figs. 1 to 7.

Length, female, O'G millim. ; male unknown.

Cephalothorax much resembles S. brevicornis. Anterior antennae 8-jointed, the

L. 2. 3. 4. 5. G. 7. 8.
proportional lengths of joints being as follows : — - -

Posterior antennae and mouth organs, with the exception of 2nd maxillipeds (fig. 3),
as in S. brevicornis. Natatory legs all more or less similar to those of S. longicornis.

262 CEYLON PEARL OYSTER REPORT.

Abdomen broad, the joints mostly quadrate, posterior margins devoid of setae. Furcal
rami short and broad, produced downwards on inner edges ; terminal setae as in
S. longicornis.

Several females were found in the washings from Muttuvaratu pearl oysters.

This species in many of its characters resembles other members of the genus,
without agreeing with any one in all respects. The jointing of the anterior antennas
and the long 2nd maxillipeds are its chief distinguishing features.

Stenhelia dentipes, a. sp. — Plate VI., figs. 8 to II.

Length, female, 0'5(> millim. ; male unknown.

Cephalothorax somewhat angular anteriorly, with long narrow pointed rostrum.

The antennae in the only specimen found were missing, with the exception of the
four basal joints on one side. Mouth organs as in S, brevicornis, with the exception
of 2nd maxillipeds, the middle joint of which is broadly ovate, and the claw curved
and slender.

The inner branch of the 1st pair of natatory legs is double the length of the outer
branch ; 2nd to 4th pairs as in S. brevicornis. Inner branch of 5th pair elongated,
terminating in a short dagger-like spine ; second joint long and gradually narrowing,
ending in a small elegant foot-shaped protuberance having 2 apical and 5 lateral seta-.
In this respect it somewhat resembles S. blanchardi, T. and A. Scott. Abdomen
similar to S. p&rplexct ; furcal rami twice as long as the width.

Found with the other members of the genus here described in the Muttuvaratu
pearl-oyster washings. It can be readily distinguished by its 5th pair of natatory legs.

Stenhelia knoxi, n. sp. —Plate X., figs. 15 to 18.

Length, female 0'07 millim. ; male unknown.

Cephalothorax and abdomen each with 5 segments. Anterior antennae very stout

6 -jointed, the proportional lengths being as follows : .

Both branches of 1st to 4th pairs of natatory legs 3-jointed ; outer branch of 1st
pair has long, strong, lateral and terminal spines; 2nd joint of 5 th pair ovate.

Three specimens, all females, were found in the Muttuvaratu pearl oyster washings.

We name this species after Robert Knox, who escaped from the King of Kandy
to the coast, at the pearl banks, in IGT'J.

Although the anterior antennae are only G-jointed instead of 8, in all other respects
the characters agree with those of Stenhelia, so we have thought it best to include
(his species in that genus.

Stenhelia minuta, n. sp. — Plate VI., figs. 21 to 24.

Length, female, 0"5 millim. ; male unknown.

This minute species bears a close resemblance to S. brevicornis, both in general

COPEPODA. -IKS

form and in its mouth organs, posterior antennae, and 2nd, 3rd, and 4tli pairs of

natatory legs. Anterior antennae 8-jointed, the proportional length of the joints

. 1. 2. 3. 4. 5. G. 7. S.

being as follows : 10. 12. 6> 10> 2. 3. 4. 6;

In its 1st pair of natatory legs it resembles S. longicoiiiis, the 5th pair being
similar to those of S. gradlicaudata.

(hie specimen only, a female, was found in the Muttuvaratu pearl oyster washings.

Its minute size, the jointing of the anterior antennee, and the 1st and :1th natatory
legs constituted its chief features.

Paras tenhelia, n. gen.

Anterior antennae 9-jointed. Inner branch of posterior antenna- 3-jointed.

Mandible palp with 2 branches each 1-jointed. Second maxilliped like a grasping
hand. First pair of natatory legs has outer branch 3-jointed, inner branch 2-jointed.
Inner branches of 2nd, 3rd, and 4th pairs all 3-jointed. Fifth pair foliaceous and
2-jointed. Abdomen in both sexes 5-jointed.

The characters which distinguish this genus from Stenhelict are the 9-jointed
antennae and the 2-jointed inner branch in 1st pair of natatory legs.

Parasteuhelia hornelli, n. sp. — Plate VII., figs. 1 to 10.

Length, female 1 millim. ; male 0'77 millim.

In general appearance, and in the jointing of cephalothorax and abdomen, this

species much resembles the members of the genus Stenhelia.

Anterior antennae of female 9-jointed, the proportional lengths of the joints being

1. 2. 3. 4. 5. G. 7. 8. 9.
as follows :

21. 20. 15. 12. 8. 11. 4. 3. 12.

The upper surface is plentifully clothed with long setae. Inner branch of posterior
antennae 3-jointed, the 2 apical joints bearing several plumose spines.

Basal joint of mandible large, with lateral warty protuberance, and 3 rounded teeth
at apex. Palp is of pyriform shape, having 3 plumose spines at apex, and lateral^
has 2 branches, each composed of 1 joint bearing several setae. Second maxilliped is
a grasping hand with ovate middle joint, terminating in a stout claw.

Inner branch of 1st pair of natatory legs 2-jointed, the 1st joint being lh times the
length of the entire 3-jointed outer branch ; terminal joint very small.

Inner branches of 2nd, 3rd, and 4th pairs all 3-jointed in both sexes. Fifth pair
foliaceous ; basal joint triangular and bearing plumose spines. Second joint in female
very long, wide at base and tapering towards apex, the edges having fine hairs, and
the apex G spines, mostly plumose. Outer branch of male 5th pair half the size of
the female and distinctly divided into 3 joints bearing spines, mostly plumose.

Several males and females were found in the washings from young pearl oysters,
also in the general washings of dredged material, in deep water off Point de Galle.

264 CEYLON PEARL OYSTER REPORT.

and in the Muttuvaratu pearl oyster washings. We have pleasure in dedicating this
new form to our friend Mr. James Hornell, who worked with Professor Herdman
in Ceylon.

The 9-jointed anterior antennae and the 2-jointed inner branch of 1st pair natatory
legs clearly separate this species from the genus Stenhetia, with which it in most
other points agrees. These characters, together with the 3-jointed inner branch of
2nd pair of natatory legs in the male, as well as the remarkable 5th pair in both
sexes, served to distinguish this species from any other genus known to us.

Parastenhelia similis, n. sp. — Plate X., figs. 8 to 14.

Length, female 1 millim. ; male unknown.

Has a general resemblance to P. hornelli, but differs therefrom in the length
of joints of anterior antenna?, in the 2nd maxillipeds, and in the 2nd branch of
5th natatory legs. Anterior antenna? 9-jointed, the proportional lengths of the

. . , , . , v, 1. 2. 3. 4. 5. 6. 7. 8. 9.

loints being as follows : „ n „ „ - — — —

J s 10. 9. 8. 7. 5. 5. 4. 2. 5.

Hand of 2nd maxillipeds gracefully curved ; the apical claw long and stout.

Inner joint of 5th pair of natatory legs long and wide ; laterally lined with fine

hairs; the terminal spines plumose. Furcal rami about twice as broad as long.

Two specimens, both females, were found in the Muttuvaratu pearl oyster washings.

Ameira minor, n. sp. — Plate V., figs. 23 to 29.

Length, female 0'4f> millim. ; male unknown.

Cephalothorax narrow-, 5-jointed. Anterior antennae 8 -jointed, the proportional

„ , . . , . „,, 1. 2. 3. 4. 5. 6. 7. 8.

lengths of the mints being as follows :

& J s 5. 20 12. 8. 4. 5. 3. 5.

The 4th joint terminates with a long narrow filament. Posterior antennae similar
to those of A. longipes. Mouth organs as in A. longiremis.

Natatory legs, 1st to 4th pairs, somewhat similar to those of A. longipes. The
5th pair much resemble those of A. tenuicornis.

Abdomen 5-jointed, the posterior edges of all the joints lined with minute hairs.
Furcal rami subquadrate, each terminating in 2 thick and 3 thin setae.

A considerable number of females only were found in the Muttuvaratu pearl-oyster
washings. This is a very small species bearing a strong resemblance to the genus
Stenhelia, but distinctly differing from members of that genus in having the inner
branch of the posterior antenna? 1 -jointed.

Ameira tenuipes, n. sp. — Plate VI., figs. 15 to 20.

Length, female 0"53 millim. ; male unknown.

Cephalothorax 5-jointed. Rostrum short and wedge-shaped. Anterior antenna?
profusely setose, 8-jointed, the proportional lengths of the joints being as follows:

COPEPODA. 265

The 4th joint terminates with a long filament. The inner
20. 21. 12. 8. 6. 6. 3. 5. ,J &

branch of posterior antennas is 2-jointed, the 2nd joint being very small.

Mouth organs and 2nd, 3rd, and 4th pairs of natatory legs as in A. minor. First
joint of inner branch of 1st pair of legs as long as entire 3-jointed outer branch ; 3rd
inner joint long and narrow.

Basal joint of 5th pair of legs triangular, bearing 2 short plumose setas and 3 plain
ones. Outer joint long and narrow, 4 times as long as broad ; fringed on both sides
with fine hairs, and having 4 terminal setas and 1 lateral.

One specimen only, a female, was found in the Muttuvaratu pearl oyster washings.
Although the inner branch of the posterior antennas is 2-jointed, we have thought it
best to include this species in the genus Ameira, with which it agrees in all other
particulars. The 1st and 5th natatory legs readily distinguish it from other species.

Ceylonia, n. gen.

Cephalothorax and abdomen each 5-jointed. Anterior antennas 7 -jointed. Inner
branch of posterior antennas 1 -jointed. Mandible palp with one small branch. Second
maxilliped non-prehensile. Inner branches of 1st to 4th pairs of natatory legs all
2-jointed ; outer branches 3-jointed ; 5th pair foliaceous.

The genus Ceylonia is nearly related to Mesochra, and might have been incor-
porated therewith but for the structural difference in the 1st pair of natatory legs
and in the maxillipeds.

Ceylonia aculeata, n. sp. — Plate VII., figs. 11 to 23.

Length, female 1"2 millim ; male 1 millim.

Body robust throughout; cephalothorax and abdomen each 5-jointed, the first two
abdominal joints imperfectly divided. Rostrum short and blunt.

Anterior antennas short and stout, thickly setiferous, 7 -jointed, a long thick filament
protruding from the apex of 4th joint. The proportional lengths of the joints are as

1. 2. 3. 4. 5. 6. 7.
folWs : 16. 12. 16. 9. 3. 6. 11.

Outer branch of posterior antennas 2-jointed, the outer edge and apex of 2nd joint
lined with 6 stout spines ; inner branch composed of one joint with 2 ajiical spines.

Biting part of mandible consists of 3 large teeth ; palp with small branch, spinous
at apex. First maxilliped has terminal claw and two 1 -jointed branches with apical
plumose setas. Second maxilliped wedge-shaped, non-prehensile, but with small
curved rudimentary claw.

Inner branches of 1st to 4th natatory legs 2-jointed; outer branches 3-jointed.
Inner branches of 1st pair only § the length of outer branch, both bearing strong
spines ; a remarkable rod-like projection with hirsute termination extends from the
centre of 1st joint of inner branch. The middle joint of outer branch of male

•_' .\j

2'if; CEYLON PEARL OYSTER REPORT.

3rd pair of legs bears a long stout aculeate spine. Fifth pair of legs foliaceous ;
outer joint in female roundly ovate, both clothed with long spinous seta?. In the
male 5th pair the joints are coalescent and terminate in dagger-shaped spines and
plumose setae. Furcal rami about 1^ times as long as broad, each bearing a long
thick terminal spine and short setae.

Several females and 2 males were obtained from young pearl oyster washings, and
from deep water off Point do Galle. The anterior and posterior antennae, the mouth
organs and the 1st and 5th pairs of natatory legs are clear distinguishing characters
of this species.

Laophonte serrata, Claus.
Laophonte inornata, A. Scott.

Both of the above were taken at Cheval Paar, and were also found in general
washings of Invertebrates from the pearl oyster beds.

Laophonte hirsuta, n. sp. — Plate VIII. , figs. 1 to 8.

Length, female 0'5 millim. ; male unknown.

Lateral edges of cephalothorax and abdomen fringed with minute hairs, giving the
animal a hirsute appearance. First cephalic segment quadrately shield-shaped,
produced postero-laterally, and ecpialling in size the rest of the cephalothorax and
abdomen.

Anterior antennas 6-jointed, the proportional lengths of the joints being as

] 2. 3. 4. 5. 6.

follows : — : — — '- — '- — : '- The upper side is clothed throughout with short seta?,

13. 14. 14. 4. 3. 10. " &

the protuberance of the 4th joint leading to a long narrow filament.

Posterior antenna? and mouth organs, with the exception of mandible, as in
L. horrida. Mandible elongated and narrow, the palp being long and slender. Inner
branch of 1st pair natatory legs remarkably robust, terminating in a very small joint
and a short stout curved claw. Outer branch 2-jointed, the 2 joints not half the
length of the 1st inner joint. The outer branch in 2nd, 3rd and 4th pairs is 3-jointed,
the inner 2-jointed. The 5th pair have small basal joints and a long narrow second
joint armed with plumose seta?. Furcal rami small, subcpuadrate.

Eleven specimens, all females, were obtained from the Muttuvaratu pearl oyster
washings and the general washings of dredged Invertebrates.

The 1st and 5th natatory legs are sufficiently diagnostic of this species.

Laophontella, n. gen.

Body somewhat pyriform, the cephalic segment nearly half the animal's entire
length. Anterior antenna? 5-jointed. Posterior antenna? and mouth organs appear to
be as in Laophontodes. The 1st, 2nd, and 3rd pairs of natatory legs have both inner

COl'EPODA. 26?

and outer branches 2-jointed, 4th pair with outer branch 3-jointed, and inner branch
with 1 joint only ; 5th pair 2-jointed, foliaceous.

Laophontella differs from both Laophonte and Pseudolaojjhonte in the absence of
claws in the 1st natatory leg ; from Laoj>hontodes in the inner branch of 4th pair
being only 1 -jointed.

With only one specimen, however (a female), to judge from, the generic characters
may in the future require some revision.

Laophontella typica, n. sp. — Plate VIII., rigs. 9 to 16.

Length, female, 0'5 millim. ; male unknown.

Cephalic segment long and tumid ; produced posteriorly into long acute spines.
Lateral edges of abdomen more or less notched. Anterior antennas nearly half as
broad as long, 5-jointed, profusely setiferous, the proportional lengths of the joints

1. 2 3 4 5

being as follows: ---'—' ' Q' The 1st joint has two claw-like spines, and the 3rd

joint another, of larger size.

Mouth organs similar to those of Laophonlodes. Branches of 1st pair of natatory
legs of equal length ; outer branch 3-jointed, as are the outer branches of 2nd, 3rd,
and 4th pairs ; inner branch 2-jointed, the 1st joint being double the length of the
2nd, both branches terminating in long setse. Inner branch of 2nd and 3rd legs
2-jointed, and of the 4th 1-jointed, all armed with strong spines. Basal joint of
5th pair small and spinous ; outer joint small, bearing 7 spines. One specimen
only, a female, was found in the Muttuvaratu pearl oyster washings. The stout
rugged anterior antennas, the notched abdominal segments, and the inner branches of
the swimming feet clearly distinguish this species from other genera.

Cletodes linearis (Ola us).

Taken in the Suez Canal, and also in various washings of Invertebrates from the
Gulf of Manaar.

Tetragoniceps dubia, n. sp. — Plate VIII., rigs. 17 to 22.

Length, female. 0"9 millim. ; male unknown.

Cephalothorax 5-jointed, the cephalic segment equalling in length the following
three combined, and considerably stouter. Ptostrum short and blunt. Anterior
antennas 8-jointed, the 1st joint non-setose, but projecting posteriorly into a beak-
shaped protuberance. The other joints very setose, the 4th bearing a long narrow

„', r™ , . , , , . , . . 1 . 2. 3. 4. 5. G. 7. 8.
tilanient. Ine proportional lengths of the joints are — —

Posterior antennae and mouth organs generally like those of T. malleolata. Inner
branches of 1st to 4th pairs of natatory legs 2-jointed, the outer branches 3-jointed.
Fifth legs 1-jointed, with partial segmentation, and having 10 seta?. A pyramidal
spine projects from the surface. Furcal rami about twice as long as broad.

2 m 2

2(58 CEYLON PEARL OYSTER REPORT.

One specimen only, and that possibly an immature one, was found in the
Muttuvaratu pearl oyster washings. It is nearly related to T. malleolata, with
which we were at first disposed to place it. The 5th leet are, however, very different
from, and the furca much shorter than in that species, so that it seems necessary to
separate the present form.

Tetragoniceps minor, n. sp. — Plate VIII. , figs. 23 to 28.

Length, female, 0'5 millim. ; male unknown.

Closely related to T. bradyi ' ; differing, however, from that species in the jointing

of the anterior antennae, and in the long narrow furcal rami. Anterior antennae

1 2 3 45678
8-iointed, the proportional lengths being as follows : A long

beak-like hook projects from the 2nd joint, by which it differs from T. consimilis.

The posterior antenna?, the mouth organs, and the 5 pairs of natatory legs are
much the same as those of T. bradyi.

One specimen only was found in Muttuvaratu pearl oyster washings. The beaked
2nd joint of the anterior antenna? sufficiently distinguishes it from others of the
genus.

Dactylophusia tisboides (Claus).
This littoral species was taken between Port Said and Suez.

Dactylophusia latipes (T. Scott).

Taken sparingly on the Ceylon pearl banks. Only previous record is Gulf of
Guinea.

Dactylophusia dentata, n. sp. — Plate IX., figs. 1 to 10.

Length, female 1*2 millim. ; male 0'83 millim.

Cephalothorax robust ; cephalic segment about as long as the rest of the thoracic
segments combined. Third and fourth segments have remarkably sharp dorsal teeth ;
abdomen narrow, little more than one-third the length of the cephalothorax ; lateral
margins of genital segment produced into a large blunt tooth. Anterior antenna?

8-iointed, the proportional lentrths being as follows :
J i l & & 10. 11. 8. 9. 3. 4. 3. 4.

The prolonged apex of joint 4 bears a long broad filament. Inner branch of
posterior antenna? 2-jointed. Mandible palp 2-branched, the primary branch having
long terminal seta?. Second maxilliped has an angular hand and terminal claw of
about the same length. Both branches of 1st pair of natatory legs 3-jointed ; the
basal inner joint half as long again as the entire outer branch ; the other joints very
small.

In the male the 2nd joint of inner branch of 2nd pair is produced into a long
pointed dagger-like spine, broad at base. Fifth pair of female 2-jointed, foliaceous,

COPEPODA. 269

the inner joint ovate; those <>t the male similar but smaller. Furcal rami sub-
quadrate, about twice as long as broad, a thick chitinous band lining the inner edges.
Ten males and 5 females were found in the Muttuvaratu pearl oyster washings.
The dentated thoracic and 1st abdominal segments, the 2nd maxillipeds, the male
2nd natatory legs, and the furcal rami clearly distinguish this species.

Dactylophusia havelocki, n. sp. — Plate IX., figs. 11 to 18.

Length, female 1 millim. ; male unknown.

Anterior antennae short, 8-jointed, the joints short, length and breadth of each

nearly equal. Fourth joint bears a long narrow filament, and tbe proportional

, „ . . . 1. 2. 3. 4. 5. 6. 7. 8.

lengths of the joints are : 9 8 5 6 3 4> 27~6.

Mandible palp 2-branched, secondary branch small, distinctly 2-jointed. Hand of
2nd maxilliped rounded on one side, flat on the other ; claw slender. Natatory legs
similar to D. dentata ; the inner branch of the 5th pair however is nearly quadrate
instead of ovate. Furcal rami nearly twice as broad as long ; basal portion of apical
spines thick and jointed.

A few specimens, all females, were found in the Muttuvaratu pearl oyster washings.
The short anterior antennas and furca, coupled with the shape of the mandible palp,
and the inner joint of the 5th natatory legs, characterize this species.

Dactylophusia hirsuta, a. sp. — Plate IX., figs. 19 to 24.

Length, female 1'2 millim. ; male unknown.

All the segments of the abdomen covered with rows of fine short hairs. Anterior

antennas 9-jointed, the 4th joint bearing a long filament.

. . , . . . . . „ „ I. 2. 3. 4. 5. 6. 7. 8. 9.

Ihe proportional lengths ol the joints are as follows : 1 -

Basal joint of 2nd maxilliped has a row of small hairs near apex, and three terminal
plumose setae ; hand small ; the claw 2-jointed, long and narrow.

Inner branch of 1st pair of natatory legs as in D. dentata, but with shorter
terminal spines ; 5th pair not unlike those of D. dentata, but the length and
armature of the setae are distinctly different, and each joint has a pellucid patch on
its surface. Furcal rami very short and hirsute.

Three specimens, all females, were found in the Muttuvaratu pearl oyster washings.
The 9-jointed anterior antennas, the hirsute abdomen, 2nd maxillipeds and furca,
and the 5th pair of natatory legs serve to distinguish this species.

Dactylophusia ceylonica, n. sp. — Plate IX., figs. 25 to 32.

Length, female 1'3 millim. ; male 0"96.

Posterior dorsal edges of thoracic and abdominal segments have each a row of fine

270 CEYLON PEARL OYSTER REPORT.

hairs. Anterior antennae 8-jointed, the proportional lengths of the joints being as

follows : r* ,' '—— ' .' r . The 4th joint bears a long thin filament.
11. 11. 5. 8. 3. o. 2. b. J &

First pair of natatory legs of female same as in D. hirsuta ; the inner branch in male
has a remarkably long stout spine equalling in length the 1st joint, projecting from
the 2nd basal joint. The 2-jointed inner branch of 2nd pair in male has 3 thick more
or less curved spines at apex of 2nd joint. Outer joint of 5th pair in female about
equal in size to the 1st joint. In the male both joints are exceedingly small.

Eighteen females and 13 males were found in the Muttuvaratu pearl oyster
washings. The chief distinguishing characters of this species are the inner joints of
1st and 2nd male natatory legs, and the 5th pair in the female.

Dactylophusia hamiltoni, n. sp. — Plate X., figs. 1 to 7.

Length, female I'l millim. ; male unknown.

Cephalothorax and abdomen each with 5 segments.

Anterior antenna? 8-jointed, the proportional lengths of the joints being as
. „ 1. 2. 3. 4. 5. 6. 7. 8.

f0ll°WS: 12.T2. 10. 11.3.G. 4. 7.

A long filament springs from the prolongation of the 4th joint. Outer branch of
posterior antenna? 3-jointed, a 2-jointed inner branch springing from the basal joint.
Second maxillipeds large ; the apical claw strong, blunt at end. Inner joint of 5th
pair of natatory legs subquadrate, about twice as long as broad. Abdomen long and
slender ; furcal rami quadrate, about twice as long as broad.

One specimen only, a female, was found in the Muttuvaratu pearl oyster washings.

The form of the 2nd maxillipeds, and 5th pair of natatory legs, and the abdomen,
are characteristic of this species, which we name after Colonel Hamilton, a former
inspector of the pearl banks.

Dactylophusia robusta, 11. sp. — Plate X., figs. 19 to 24.

Length, female 0"G4 millim. ; male unknown.

A small but moderately robust species with a very tumid cephalothoracic segment.

Anterior antenna? 8-jointed. Joints long and narrow, with the exception of the

1. 2. 3. 4. 5. G. 7. 8.
5th, which is very small ; the proportional lengths are : — — ■ nn — - — -„,_,„

J l i ° 14. 24. 12. 20. 4. 10. 7. 12.

Posterior antennae, mandible, and maxilla similar to those of D. gracilicaudata >
2nd maxillipeds have the palm straight and the lower side rounded. Outer branches
of the 1st natatory legs much shorter than the inner blanches. The middle joint of
the outer branches longer than either the basal or apical joints ; 2nd, 3rd, and
4th legs resemble those of D. tisboides. The 5th pair have a large primary joint and
a moderately long and narrow secondary joint. The primary joint is furnished with
5 seta?, and the secondary with G seta?. Abdomen 4-jointed, about half as long as

COPEPODA. 271

the combined lengths of the cephalic and thoracic portions. Furcal rami small,
longer than broad.

A few specimens were found in the washings from the Mnttnvaratu pearl oysters.

D. robusta differs from other species in the structure of the anterior antennae, and
the 1st and 5th natatory legs.

Dactylophusia laticaudata, n. sp. — Plate XT., figs. 1 to R.

Length, female 0*6 millim. ; male unknown.

A small flat species of a yellow colour, resembling in general appearance D.flava,
When only recently preserved, the 1st, 2nd, and 3rd thoracic segments present a
band of deep brown madder colour; this band eventually disappears in spirit-
specimens, and only the general colour remains. Anterior antenna? 6-jointed, short

. , t , 1. -2. 3. 4. 5. G.

and robust ; the proportional lengths are : —

lo. 12. J. o. J. 4.

Secondary branch of posterior antennae 2 -jointed ; basal joint very short ; 2nd joint
long. Mandible as in D. tisboides; palp with 2 nearly equal branches. The lower
branch is furnished with 2 strong spines situated in the middle of the external
margin. Maxilla and 1st maxilliped resembling those of D. tisboides. Second
maxilliped long and narrow, both surfaces slightly rounded ; terminal claw very
strong. Outer branch of 1st natatory legs 3-jointed, very short ; inner branch has a
long and very wide 1st joint and one small terminal joint ; 2nd, 3rd, and 4th legs
resembling in general those of the genus ; the terminal spines have ring-like
markings. The 5th legs have the primary joint large and foliaceous, much longer than
broad, with 5 short, stout terminal spines ; secondary joint small with 2 strong
spines on the outer margin, 2 terminal ringed spines and 1 small spine on the inner
distal margin. Abdomen 4-jointed, very wide. Furcal rami small and tumid.

Several specimens of this curious species were found in the Muttuvaratu pearl
ovster washino-s.

Dactylophusia semula, n. sp. — Plate XL, figs. 9 to 12.

Length, female 0-4 millim. ; male unknown.

In general appearance very like D. laticaudata, but smaller and less robust. The

colouring is the same as in that species.

Anterior antennae narrow, 7-jointed. The proportional lengths of the joints are

„ .. 1. 2. 3. 4. 5. G. 7.

as follows :

13. 12. 10. 11. 4. 3. G.

Posterior antennse, mandible and palp, maxilla and maxilliped as in D. laticaudata.

The 1st to 4th natatory legs resemble those of D. laticaudata, except that the basal

joint of the inner branch of the 1st is less tumid. The 5th legs in this species also

have the primary joint large and foliaceous, but proportionally broader than long, and

272 CEYLON PEARL OYSTER REPORT.

the terminal spines are shorter and less tumid ; secondary joint small. Marginal
spines, with the exception of the inner sub-terminal one which is very strong, short
and slender. Abdomen less tumid than in D. latieaudata.

Several specimens, all females, from the same locality as the foregoing species, from
which it is distinguished by the structure and proportional lengths of the joints of
the anterior antennas, and by the 1st and 5th legs. The two foregoing species
differ in the structure of their appendages, especially in the 1st legs, which have the
inner branch only 2-jointed, from the general type of Dactylophusia, and may some
time require a separate genus.

Dactylophusia platysoma, n. sp. — Plate XI., figs. 13 to 18.

Length, female 0'62 millim. ; male unknown.

In general appearance more like a Porcellidium than a Dactylophusia, and it is
only when the appendages are examined that it becomes clear that it is not a
Porcellidium; neither can it be said to be a typical Dactylophusia, though pro-
visionally referred to that genus. Anterior antenna moderately long and slender,

. . . , , ,. ,. , . ., 1- 2. 3. 4. 5. 6. 7. 8. 9.

9-jomted ; the proportional lengths are : 13 18 10< 9 4 5 2 2> 4<

Posterior antenna?, mandible and palp, maxilla and 1st maxillipeds nearly as in
D. tisboides ; 2nd maxillipeds elongate, with a strong terminal claw. First natatory
legs resembling those of D. tisboides ; 2nd, 3rd and 4th though generally like those
of Dactylophusia, are more slender than the corresponding legs of any member of the
genus known to us. The 5th feet have the primary joint large and foliaceous. The
extremity of the joint is fringed with fine hairs, amongst which are 3 prominent
setae ; secondary joint not distinctly separated from the primary one, with rounded
margins and furnished with 6 apical setse. Abdomen very flat, 4-jointed, furcal
rami short.

Six females were found in the washings from the Muttuvaratu pearl oysters.

Thalestris mysis, Claus.
Found in the Gulf of Suez and again at Cheval P.aar, Ceylon.

Pseudothalestris imbricata, Brady — Plate XL, figs. 19 to 24.

This species was described from a single specimen (a male) in the Report on the
" Challenger " Copepoda by Professor Brady. No further specimens seem to have
been discovered until now. In the present collection a single female was found in
washings from the Muttuvaratu pearl oysters, which from its general resemblance in
structural detail we have concluded is the female of P. imbricata.

Length, female 0'65 millim.

In general agreement with the recently described species of this genus, it is more
like a small Westivoodia than a Thalestris. The outer branches of the 1st natatory

COPEPODA. 273

legs are very small and distinctly 2-jointed. Anterior antennae 6-jointed ; pro-
portional lengths as follows : -
1 b 9. 12. 21. 4. 7. 7.

Posterior antennas, mandible, maxilla and maxillipeds similar to those figured by
Brady. Natatory legs 1 to 4 also similar. The 5th legs have a large primary
joint and a small secondary joint each furnished with a number of hairs.

Furcal rami extremely short, much broader than long.

Harpacticus chelifer (Muller).
A common littoral British species. It occurred only once, in a tow-net gathering
from Marichchukaddi, Ceylon.

Peltidium ovale, n. sp. —Plate XIII., figs. 1 to 6.

Length, female 1'6 millim. ; male unknown.

Body ovate, cephalothorax and abdomen not clearly separated. Anterior antennas

short, 6-jointed, the proportional lengths of joints being as follows :

x * ° ° 13. Id. 10. o. Z. o.

Most of the joints are densely setiferous, the 3rd and 4th also bearing a long

filament.

Posterior antennas and mouth organs as in P. purpureum. Outer branch of
1st pair of natatory legs 2-jointed, with marginal hairs on both sides ; inner branch
3-jointed, half as long again as the outer, the middle joint about twice the length of
the 1st, and the 3rd joint very small, having at the apex two narrow curved claws.
In the 2nd, 3rd, and 4th pair, both branches are 3-jointed, the outer branch armed
on outer side with lateral aculeate plumose spines ; the inner side and inner branch
both bearing plumose setae. The 5th pair of legs 2-jointed, the basal joint very small
and produced on each side ; the outer joint long and stout, with terminal aculeate
spines.

Three females only were found in the Muttuvaratu pearl oyster washings and in the
general washings of Invertebrates. This and the 4 following species all clearly agree
with Philippi's original description of the genus except as to the anterior antennae,
which he gives as 9-jointed, whereas our 5 new species are 6- and 7 -jointed. Seeing
that Philippi knew of only one species, P. purpureum, we think the generic character
should be altered to read — G- to 9-jointed, to admit these new forms.

The rounded forehead and the 5th pair of natatory legs sufficiently distinguish this
species from the others.

Peltidium angulatum, n. sp. — Plate XIIL, figs. 7 to 11.

Length, 1"2 millim. ; male unknown.

Body angular, with large anterior protuberance or rostrum. Anterior antennse

.... 1. 2. 3. 4. 5. 6. 7.

7-jointed, the proportional lengths being as follows : ,.

2 N

•274 CEYLON PEARL OYSTER REFORT.

First pair of natatory legs shorter and stouter than those of P. ovale ; the basal
joint of outer branch bears 2 small elongated processes in place of spines. Basal
joint of 5th pair produced on one side into a long linear projection with apical spine ;
outer joint elongated, narrowing towards apex, armed with strong plain and plumose
spines. Two specimens, both females, were found in the Muttuvaratu pearl oyster
washings. It differs from P. ovale in the anterior antennae, the 5th pair of legs, and
particularly in the arrangement of the chitinous bands or reticulations of the carapace.

Peltidium speciosum, n. sp. — Plate XIII., figs. 12 to 17.

Length, female l'l millim. ; male unknown.

Body resembles P. angulatum in shape, but is differently reticulated, the chitinous

bands being thicker. Anterior antennae stout, 7 -jointed, the filaments and setae as in

. . . 1. 2. 3. 4. 5. 6. 7.

the two previous species ; the proportional sizes are :

First pair of natatory legs very robust, In other respects they and the other pairs
agree with P. angulatum. Fig. 17 represents a smaller form with thinner bands.

A number of specimens, all females, were found in the Muttuvaratu pearl oyster
washings. The jointing of the anterior antennae, and the robustness of the 1st pair
of natatory legs, serve to distinguish this species.

Peltidium serratum, n. sp. — Plate XIII., figs. 18 to 22.

Length, female 1'6 millim. ; male unknown.

Body robust, rostrum broad, with 4 indentations on anterior surface ; margins of all

the cephalothoracic segments serrated. Anterior antennae 6-jointed, the proportional

n , • • , ■ p ii 1. 2. 3. 4. 5. 6.

lengths of the lomts beinc; as follows : „ ^„ , , — ; — — —

to •' fo 20. 20. 14. 4. 4. 7.

Outer branch of 1st pair of natatory legs robust. Fifth pair foliaceous, 1 -jointed,
with a long spear-shaped plumose apical spine and several lateral spines, some of them
plumose ; anteriorly drawn out into a curved protuberance with terminal spine
representing a rudimentary basal joint.

Three specimens, all females, were found in the bottom tow-net at Chilavaturai,
Ceylon. The character of the reticulation on the carapace and the remarkable
5th natatory legs clearly distinguish this species from others.

Peltidium perplexum, n. sp. — Plate XIII., figs. 23 to 27.

Length, female l'l millim. ; male unknown.

Body and character of reticulation resemble P. speciosum. Anterior antennae

, , • , , • • • P n 1. 2. 3. 4. 5. 6. 7.
7 -jointed, the proportional lengths of joints being as follows : — —

Natatory legs similar to those of P. angulatum.

Two specimens, both females, were found in the Muttuvaratu pearl oyster washings.

This differs from other species chiefly in the proportional lengths of joints of

COPEPODA. 275

anterior antennae. Cleve has formed a genus Reticulina for the species R. aurivillii,
which is certainly a Peltidium, but it is not sufficiently well figured to enable us to
compare it with any of the foregoing species.

Ilyopsyllus affinis, T. Scott.

Appeared once between Port Said and Suez, and again in the Gulf of Manaar, also
at Kodramallai, north of Karativo, and 2|- miles south-south-west of Ohilavaturai.

Porcellidiurn fimbriatum, Glaus — Plate XII., figs. 1 to 10.

Lenoth, female 0"7 millim.

. . . • -, ■ i , , „■ ■ 1. 2. 3. 4. 5. 6.

Anterior antennae 6-jomted ; proportional lengths ot joints : — — — — — -

A few specimens, all females, of this species, which appear to be identical with
Clalts' P. fimbriatum, were found in the washings from the Muttuvaratu pearl
oysters. The chief points that distinguish this species from the others are the 5th
feet, the abdomen, and the furcal rami.

Porcellidiurn brevicaudatum, n. sp. — Plate XII., figs. 11 to 14.

Length, female 0"G7 millim.

A . . . , ,„ 1. 2. 3. 4. 5. 6.

Anterior antennas G-iointed, as follows :

J 13. 17. 12. 8. 4. 2.

This species is easily distinguished from the others by its smooth carapace and
ciliated margins, the large 5th feet, the short abdomen, and the furcal rami.

Six specimens, all females, were obtained from the Muttuvaratu pearl oyster
washings and from the general washings of Ceylon Invertebrates.

Porcellidiurn acuticaudatum, n. sp. — Plate XII. , figs. 15 to 18.
Length, female 0*6 millim.
Anterior antennas 6-jointed ; proportional lengths as follows : — — — — —

The chief features of this species are its moderately large 5th feet with rounded
apex, the small abdomen produced laterally on each side, and the acutely pointed
apex of the furcal rami.

Three females of this distinct species were found in the washings from the
Muttuvaratu pearl oysters.

Porcellidiurn ravanae, n. sp. — Plate XII., figs. 19 to 22.
Lenoth female 0'6 millim.

Anterior antennae 6-jointed ; proportional lengths as follows : * — — —

10. 18. 13. 8. 5. o.

The distinguishing characters of this Porcellidiurn are the moderately wide 5th

feet, which taper off to an acute point, the small abdomen, the posterior angles of

which are not so much prolonged as in P. acuticaudatum, and the obliquely rounded

2 n 2

2 76 CEYLON PEARL OYSTER REPORT.

external margin of the furcal rami. Three females of this species were found in the
washings from the Muttuvaratu pearl oysters.

Idya furcata (Baird).

' A common British littoral species. Occurred at 7 stations from the English Channel
through the Mediterranean and Gulf of Suez to the Red Sea.

Idya longicornis, T. Scott.

Found in the general washings from Ceylon Invertehrates. Previously known only
from British waters.

Pseudanthessius gracilis, Claus — Plate XIV., figs. 19 to 23.

One specimen was found in the general washings of the Ceylon Invertehrata
ohtained ahout the pearl banks. We give some additional figures of this species.

Pseudanthessius maximus, n. sp. — Plate XIV., figs. 1 to 11.

Length, female 3' 5 millims. ; male 2-7 millims.

Cephalothorax 6- jointed, the lateral spaces between the joints giving it a coarsely
pinnatifid appearance. Abdomen of female 4-jointed, male 5-jointed, the 1st segment
in the male being much longer and wider than any of the others.

Anterior antennae 7 -jointed, each joint bearing several short spinous setae, and the

. , , . . . . ,. 1. 2. 3. 4. 5. 6. 7.

proportional lengths being: as follows : „ nn . „ ^ „ -

Posterior antennae 4-jointed, the 3rd joint much the smallest ; the 4th bears a stout
blunt hooked spine. Mandible is produced apically into a long recurved spine with
toothed edges, also a smaller toothed spine, and toothed edge. The pal}) is short,
armed with three apical spines and a lateral one. First maxilliped has a stout basal
joint, with an outer joint extended into 2 curved hairy spines. Second maxilliped of
female has an oval middle joint terminating in a short claw ; that of the male is a
strong grasping hand, the terminal claw long and stout.

First pair of natatory legs has both branches 3-jointed, the outer one armed with
serrated lanceolate spines ; both branches have numerous plumose setae. Fourth pair
2-branched ; the outer one 3-jointed, armed with short ovate serrated spines, the
inner branch consists of 1 long joint gradually widening to the apex ; the lateral
posterior edges are produced into spines, between which are 2 terminal plumose setae.
The 5th pair consist each of a long curved joint with 3 terminal plumose spines.
Furcal rami about 3 times as long as broad, slightly tapering to apex.

Several males and females were taken by surface tow-net in Galle harbour.

This species is easily distinguished by its large size, by the mandible and posterior
antennae, and by the 4th and "5th pair of natatory legs.

COPEPODA. -277

Pseudauthessius chelifer, n. sp. — Plate XIV., figs. 12 to 13.

Length, female 1 millim. ; male unknown.

Cephalothorax G-jointed, ovate. Abdomen 4-jointed, the 1st joint swollen and
rounded anteriorly, narrowing to base. Anterior antennas 7-jointed, the proportional

1. 2. 3. 4. 5. G. 7.
lengths of the joints being as follows : 16> 24. 8. 21. 1G. 12. 12.

Posterior antennas 3-jointed, the apical joint having 3 long terminal spines and a
long broad curved terminal claw dentated on upper side. Mandible small, anteriorly
extended into a serrated spine ; palp large, having 3 terminal spines. The 1st
maxilliped narrow, ending in a denticulate spine and a smaller lateral spine. The
2nd maxilliped consists of a long narrow curved joint having 2 small lateral spines and
3 terminal spines. Inner branch of 4th pair of natatory legs consists of one small
narrow joint with terminal spine. Furcal rami about 3 times as long as broad.

Several specimens, all females, were found about the pearl banks. A very distinct
species, readily recognized by its posterior antennas, the 2nd maxilliped and the 4th
pair of natatory legs.

Pseudanthessius concinnus, n.sp. — Plate XIV., figs. 24 to 30.

Length, female 0"85 millim. ; male unknown.

Cephalothorax ovate, similar to P. gracilis, but considerably smaller. Abdomen

5-jointed. Anterior antennas 7-jointed, the proportional lengths of the joints being as

, .. 1. 2. 3. 4. 5. 6. 7.

follows : — 4< g_ 16> 16_ l% --

Posterior antennas nearly as in P. gracilis. Mandibles consist of a curved joint,
tumid in centre, with narrow, blunt termination. First maxilliped 1-jointed, long,
narrow towards apex, with strong lateral and terminal spines. Second maxilliped
2-jointed, the first joint rather longer than broad ; terminal joint very small with
2 strong apical spines. Both branches of 1st pair of natatory legs 3-jointed ; inner
branch of 4th pair 1-jointed with truncate base terminating in large serrated lanceolate
spine and one plain spine ; outer branch 3-jointed, having serrated lanceolate spines.
Furcal rami long and narrow.

One specimen only, a female, was found in the general washings from Ceylon
Invertebrata.

The mouth organs, the inner branch of 4th pair of natatory legs and the furcal
rami are the distinguishing features of this species.

Pseudanthessius liber (Brady and Kobeutson).
Found amongst the general washings of Invertebrates from the pearl oyster beds.

Lichomolgus minor, A. Scott.
Found at 2 stations only, and far apart, viz., between Port Said and Suez, and
amongst the washings of young pearl oysters, Ceylon.

278 CEYLON PEARL OYSTER REPORT.

Lichomolgus gracilis, n. sp. — Plate XV., figs. 1 to 9.

Length, male 0*7 millim. ; female 1 millim.

Cephalothorax (female) ovate, 6-joiuted, abdomen 3-jointed, the 1st considerably
longer and wider than the combined succeeding 2 joints. First joint of male abdomen
quadrate ; more than 4 times the size of the 2nd joint.

Anterior antennae (female) 7-jointed, the proportional lengths of the joints being as

, „ 1. 2. 3. 4. 5. 6. 7.

follows : ■— —

17. 25. 9. 11. 12. 7. 5.

Posterior antennae 3-jointed, the apical joint terminating in a strong curved claw,
and having 3 small lateral spines. Mandible has an angular quadrate base, and is
pectinated along upper edge ; palp short, with 3 spines,

First maxilliped has outer joint triangular, sharp and wedge-shaped, and has a
serrated curved lateral spine arising from centre ; outer joint of 2nd maxilliped
(female) very small, with stout apical spines ; in the male it is a grasping hand with
long curved claw. Inner branch of 4th pair of natatory legs 2-jointed. Furcal
rami divergent, about 4 times as long as broad.

Several males and females were found in the general washings of dredged
Invertebrates. The mouth organs, posterior antennas, and furcal rami sufficiently
distinguish this species.

Lichomolgus ieversi, n. sp.— Plate XV., figs. 10 to 17.

Length, male 0'96 ; female 1*06.

Cephalothorax 6-jointed ; cephalic segment subquadrate ; abdomen 4-jointed, the
genital segment smaller than in the other species of the genus. Anterior antennae

7-jointed, the proportional lengths of the joints as follows :

Posterior antennae 3-jointed ; the middle joint small ; apical joint longer than the
combined 1st and 2nd ; with four terminal curved spines, two of which are moderately
stout. Mandibles long and narrow, coming to a fine point, edges hairy. Terminal
joint of 1st maxilliped drawn out, forming a fine ciliated stylet ; there is also one
lateral spine ; 2nd maxilliped (female) 3-jointed, with very short terminal spine ;
2nd maxilliped of male forms a chelate hand with very long rounded claw. Inner
branch of 4th pair of natatory legs 2-jointed, the outer branch equals 3 of the inner
and has truncated apex ; outer branch has 5 lanceolate spines. Furcal rami very
long and nearly parallel.

About 20 females and 4 males were found in the Muttuvaratu pearl oyster
washings and in the Invertebrata washings. The mouth organs, antennal joints, and
the furca are the chief distinguishing features of this species, which is named in
honour of Mr. R. W. Ievers, Government Agent of the Northern Province of Ceylon,
where the pearl banks are situated.

COFEPODA. 279

Lichoinolgus buddhensis, n. sp. — Plate XV., figs. 18 to 24.

Length, female 1 millim. ; male unknown.

Cephalothorax broadly ovate, about 4 times as long as the abdomen, which is

3-jointed ; the genital segment being about 4 times the size of the 2 combined

succeeding joints ; it is much swollen in the middle. Anterior antennae 7 -jointed, the

„ , . . , . „ „ 1. 2. 3. 4. 5. 6. 7.

proportional lengths ol the joints being as lollows : — — — r—

17. ol. 7. lo. 14. lo. 10.

Mandible and palp short. Maxillipeds and natatory legs similar to P. ieversi.
Furca quadrate, very small.

Several specimens, all females, were found in the general washings of dredged
Invertebrates. The very short abdomen and furca are quite characteristic of this
species — named in honour of the celebrated home of Buddhism from which it came.

Lichomolgus lankensis, n. sp. — Plate XV., figs. 25, 26.

Length, female I'O millim. ; male unknown.

Cephalothorax ovate. Abdomen 3-jointed ; genital segment about as long as the
combined two succeeding joints and furca. Anterior antennae 7-jointed, the propor-
tional lengths being as follows : — : '- '- — -

b to 22. 29. 10. 14. 10. 7. 5.

Posterior antennae, mouth organs, and natatory legs as in L. gracilis.

Three specimens, all females, were found in the general washings of dredged
Invertebrates Its general form, and the comparative shortness of the anterior
antennae and furca, distinguish this species from others of the genus.

Lichomolgus simplex, n. sp. — Plate XV., figs. 27 to 34.

Length, female 0'88 millim. ; male 0*8 millim.

Cephalothorax 6-jointed, abdomen (female) 4-jointed, male abdomen 5-jointed,
genital segment double in size that of the female ; anterior antennae 6-jointed, the

proportional lengths being as follows : -

r l & & 13 2.2 8_ 22. 18. 18.

Posterior antennae 3-jointed, the middle one very short ; terminal joint 3 times
the length of the second, with 2 apical spines. Mandible constricted in centre ; outer
portion somewhat quadrate, with ciliated edges bearing 2 small corner filaments and
a plumose spine. Maxillipeds similar to L. buddhensis, but stouter. Natatory legs
as in L. gracilis.

Furcal rami about 3 times as long as broad. A few specimens of each sex were
found in the washings from sponges dredged in the Gulf of Manaar. The general
shape of the animal and of the abdomen and furca and the jointing of the antei'ior
antennae serve to distinguish this species.

280 CEYLON PEARL OYSTER REPORT.

Lichomolgus elegans, n. sp. — Plate XVI., figs. 8 to 13.

Length, female 1"5 millim. ; male unknown.

Cephalothorax 6-jointed. Abdomen 4-jointed, the genital segment being longer

than the 3 succeeding joints combined, and having a wedge-shaped notch near the

centre on each side. Anterior antennas 7 -jointed, the proportional lengths being as

, ,. 1. 2. 3. 4. 5. 6. 7.
follows : -

11. 32. 4. 11. 9. 7. 4.

Posterior antennas 3-jointed, the first joint rather longer and nearly double the
width of each of the succeeding joints. The third joint bears a strong apical claw.
Maxillipeds resemble L. buddhensis, but are stouter. Inner branch of 4th pair of
natatory legs 2-jointed, the outer joint being about double the length of the inner.
Furcal rami very short, about as broad as long.

One specimen only, a female, was found in the general washings from dredged
Invertebrates. The notched abdominal genital segment is the most striking charac-
teristic of this species.

Lichomolgus robustus, n. sp. — Plate XVI., figs. 14 to 20.

Length, female 1*1 millim. ; male unknown.

Cephalothorax robust, ovate, 6-jointed. Abdomen 4-jointed ; the genital segment

about as long as the combined 2 succeeding joints. Anterior antennae 7 -jointed, the

, , . „„ 1. 2. 3. 4. 5. 6. 7.

proportional lengths being as follows : — — — — - — —

15. 32. 5. 11. 8. 8. 5.

Posterior antennas similar to L. simplex, but more robust. Mandible stylet serrated
on outer edge. Maxillipeds and natatory legs like L. buddhensis. Furca about half
as long again as broad.

One specimen only, a female, was found in the general washings from dredged
Invertebrata. In many points there is a great resemblance between this species and
L. buddhensis; but in the jointing of the cephalothorax, and more particularly of
the abdomen, and in the small size of the 5th natatory legs in this species, the
difference is so considerable that we are justified in separating them.

Lichomolgus gigas, n. sp. — Plate XVI., figs. 21 to 26.

Length, female 2 millims. ; male 1*4 millims.

Cephalothorax ovate, 6-jointed. Abdomen, female 4-jointed ; male 5-jointed.

Anterior antennas long and slender, 7-jointed ; the proportional lengths being as

... 1. 2. 3. 4. 5. 6. 7.
follows :

12. 32. 4. 16. 12. 9. 7.

Posterior antennas, mouth organs, and natatory legs and furca nearly resemble
L. simplex.

One of each sex were found in the general washings of dredged Invertebrata.

COPEPODA. 281

The large size and the jointing of the slender anterior antennae sufficiently distinguish
this species.

Lichomolgus dentipes, n. sp. — Plate XVI, figs. 27 to 30.

Length, female 0-86 millim. ; male unknown.

Cephalothorax broadly ovate, the cephalic segment equal in size to the combined
5 following ; the edges of the 3rd and 4th segments are finely serrated. The
5th segment is very small, with sharply-pointed lateral terminations.

Abdomen very short and stout, hardly |th the length of cephalothorax ; genital
segment as long as the combined 2 following and double the width ; 4th joint the
same as 1st. Furcal rami equal in length and breadth.

Anterior antemue 7 -jointed, the proportional lengths being;: -

J *- l B fe 11. 26. 3. 7. 4. 3. 2.

Mouth organs as in Paralichomolgus. Inner branch of 4th natatory legs 2-jointed,
both joints straight and very narrow. The 5th pair have each a large tooth projecting
from inner side anteriorly.

Of this very striking species one specimen only, a female, was found in the general
washings of dredged Invertebrata. It is easily recognisable by its serrated thoracic
edges and by the 4th and 5th natatory legs — the tooth on the latter gives the specific
name.

Paralichomolgus, n. gen.

Female ; body composed of 10 segments ; cephalothorax rotund or ovate ; 5 -jointed ;
genital segment much larger than the others, being the 1st and 2nd segments united.

Anterior antennae 8-jointed. Posterior antenna?, mouth organs, and natatory legs
as in Lichomolgus. The difference between this genus and Lichomolgus consists in
the lateral prolongations of the body segments and in the jointing of the anterior
antennae.

Paralichomolgus curticaudatus, n. sp. — Plate XVI., figs. 1 to 7.

Length, female 1'2 millims. ; male unknown.

Cephalothorax ovate, 5-jointed ; the posterior edges of segments 2 to 4 being pointed.
Abdomen very short, about \th the length of the cephalothorax ; genital segment
wider than its length and having on each side posteriorly a rounded lobe ; the other
joints very small. Furcal rami very small, almost half spheres. Anterior antennae

8-iointed. the proportional lengths being as follows :
J * 1 & & 12_ 35_ 3 8# 13 g. 4. 3.

Posterior antennae 3-jointed ; the 1st and 2nd joints sub-equal ; the 3rd as long as
the combined 1st and 2nd: terminal claw thick, and obtuse at apex. Mandible and
palp as in Lichomolgus buddhensis. Maxillipeds similar to Lichomolgus ieversi,
except that the joints of the 2nd are nearly double the width of the latter. Natatory
legs also similar to those of latter species ; the 2 joints of inner branch of the 4th pair,
however, being equal in length to the 3-jointed outer branch.

2 o

282 CEYLON PEARL OYSTER REPORT.

Two specimens, both females, were found in the general washings from the dredged
Invertebrata. The short abdomen, the wide joints of 2nd maxillipeds, and the jointing
of inner branch of 4th pair of natatory legs readily distinguish this species.

Paralichoinolg'us longicaudatus, n. sp. — Plate XX., figs. 6 to 8.

Length, female l'l millims. ; male unknown.

Body sub-rotund ; 1st to 3rd joints of cephalothorax are pointed posteriorly and

with a tooth on each lateral edge of 2nd and 3rd ; 4th joint very small. Abdomen

about ^ the length of cephalothorax ; genital segment large and tumid ; the rest

3 times broader than long. Furcal rami square, very short, with long terminal setae.

. , , , . . 1. 2. 3. 4. 5. 6. 7. 8.

Anterior antenna} 8-jomted, the proportional lengths being: -

Posterior antennae, mandible, maxillipeds, and first 3 pairs and 5th pair of natatory
legs as in P. curticaudatus. The 2-jointed inner branch of 4th pair natatory legs
springs from middle of long basal joint at right angles ; the 3 joints of outer branch
being also at right angles to basal joint.

One specimen only, a female, was found in the general washings from dredged
Invertebrata. The general appearance and the 4th pair of natatory legs clearly
distinguish this species from the last described.

Hermannella arenicola, Brady.
Found in the general washings of dredged Invertebrata from the pearl banks.

Hermannella robusta, n. sp. — Plate XVII., figs. 1 to 8.

Length of female l'l millims. ; male unknown.

A very robust species with comparatively short abdomen. Anterior antenna?

„ . . , ,. . , .. , . . 1. 2. 3. 4. 5. 6. 7.

7-jomted; proportional lengths of joints : Y6~~ 3 5~~ 5_ 16- 8~ 6~^4

The posterior antenna has a short stout hook-like spine arising from the 3rd joint.
Mandible and maxillipeds have a general resemblance to the corresponding organs in
Lichomolgus. Both branches of 1st to 4th natatory legs are 3-jointed. The 5th legs
are rudimentary. Abdomen with 4 segments; genital segment large and tumid, 4th
joint longer than the 3rd ; furcal rami about twice as long as broad, and slightly
longer than the last abdominal segment.

This species is easily recognised by the robust body and short abdomen, which is
less than a fourth of the length of the body, and by the short furca. Three females
were found in the washings from Ceylon Invertebrates.

Hermannella serendibica, n. sp. — Plate XVIL, figs. 9 to 11.
Length of female, 1*16 millims. ; male unknown.
In general appearance more attenuated than H. robusta. Anterior antennae

7-jointed ; proportional length of joints : ' ' ' ' Q' ' '

COL'EPODA. 283

Posterior antennae, mandible, maxillipeds and natatory legs similar to those of
H. robusta. The 5th feet are more developed than in the previous species. Abdomen
4-jointed, rather less than half the length of the body. Genital segment large, much
wider posteriorly than in front ; 2nd, 3rd and 4th joints subequal in length and each
aboiit as long as broad. Furcal rami long and narrow, about 5 times longer than
broad and equal to the combined lengths of the 3rd and 4th joints of the abdomen.
Three females were found in washings from Gulf of Manaar sponges. This Hcrmannella
is easily identified by its attenuated form, long abdomen, with the peculiar swelling of
the genital segment, and long furca.

Hersiliodes leggii, n. sp. — Plate XVII., figs. 12 to 21.

Length of male 1'5 millims. ; female unknown.

Anterior antennas 7-iointed ; the proportional lengths are : -

J > r t & 11. 14. 7. 20. 13. 9. 12.

Posterior antenna 4-jointed, similar to that of other Hersiliodes. Mandible strong
with a well-developed biting part. Maxilla more developed than in Lichomolgus, and
bearing a number of strong apical setas. The first maxilliped has the terminal joint
strongly toothed and also furnished with a setiferous digit. The second maxilliped
well developed, in general appearance resembling that of other species of the genus.

Both branches of 1st to 4th natatory legs are 3-jointed. Fifth legs foliaceous,
subquadrangular in shape, rather longer than broad, and furnished with 3 dagger-
like spines and 1 seta. Abdomen 5-jointed, fully half as long as the body. Furcal
rami short, about as broad as long.

One specimen in washings from Gulf of Manaar sponges. This sjjecies, which we
name after Captain Legge, at present Inspector of the pearl banks, is easily
recognised from any other member of the genus by the proportional lengths of the
joints of the anterior antennas and by the quadrangular 5th legs.

Hersiliodes tamilensis, n. sp. — Plate XVII., figs. 22 to 25.

Length, female l-3 millims. ; male unknown. In general appearance resembling
the previous species. Anterior antennas 7-jointed ; proportional lengths of the

. . , 1. 2. 3. 4. 5. 6. 7.

lomts :

J 10. 10. 5. 15. 10. 7. 11.

Posterior antennas, mandible, maxilla, and 1st maxillipeds nearly as in H. leggii.
Terminal joint of 2nd maxilliped armed with 2 moderately strong spines and 2 small
setas. Natatory legs 1 to 4 somewhat similar to those of H. leggii. Fifth legs long
and narrow, about 3 times longer than broad, and armed with 3 dagger-like spines
and 1 seta.

Abdomen 5-jointed, fully half as long as the body. Genital segment long and
broad, widest near the middle ; 2nd joint quadrangular in shape, about half as long
as the genital segment ; 3rd, 4th, and 5th joints shorter than broad, and in combined

2 o 2

284 CEYLON PEARL OYSTER REPORT.

length equal to the 2nd joint. Furcal rami short and wide, ahout as broad as
long.

In washings from Muttuvaratu pearl oysters.

The proportional lengths of the joints of the anterior antennae, and the long and
narrow 5th feet, distinguish this species from any of the others.

Hersiliodes dubia, n. sp. — Plate III., figs. 18 to 27.

Length, male 1 '8 millims. ; female unknown.

Cephalothorax quadrate in form, composed of 5 segments. Anterior antenna?

6-jointed, and all clothed with non-plumose setae ; the proportional lengths are as

, .. 1. 2. 3. 4. 5. 6.

follows :

8. 6. 5. 3. 4. 8.

Posterior antennae 4-jointed, the basal joint equalling in size the 3 following.

Mandible with 2 horizontal plumose projections and 2 plumose seta?. Maxilla
with 3 terminal spinous setae, and 4 on the outer side, 2 of them plumose. First
maxilliped 2-jointed, the apical joint terminating in a strong curved claw and a
plumose spine on each side. Second maxilliped 2-jointed, the basal one with a rounded
papilla ; the hand angularly curved on outer side, terminating in a long rounded claw
bluntly rounded at apex, and having on under side 3 spinedike setae.

First 4 pairs of natatory legs 2-branched, each having 3 joints with the edges
mostly clothed with fine hairs. Fifth pair each consist of a quadrate joint with
3 strong spines and a few hairs and setae at base. Abdomen rather shorter than the
cephalothorax, 5-jointed, the genital segment very large, nearly square, and having
hooked posterior lateral terminations.

Furcal rami linear, about 4 times as long as broad, with a small spine on each
outer side and terminating in 3 setae of unequal lengths.

One specimen only, a male, was taken in the Suez Canal.

This species agrees, in most particulars, with Cantj's Hersiliodes. Canu, however,
gives 7 joints in the anterior antennae, although his careful drawing of H. pelseneeri
shows only 6 joints. It is evident that the species comprising the genus Hersiliodes
undergo considerable changes in their various ecdyses, and in the absence of an adult
female we can only provisionally place our species in this genus.

Family: ONCEID^E.
Oncea venusta, PmLirpi.

Oncea media, Giesbr,

Oncea minuta, Giesbr.

Oncea mediterranea, Glaus.

All the above were generally distributed over the entire voyage. 0. media was
found only once about Ceylon, viz., at Mudalaikuli Paar. 0. mediterranea occurred

COPEPODA. 285

twice in Ceylon, viz., at Muttuvaratu Paar and at Talaivillu Paar. 0. venusta was

taken at 10 and 0. minuta at 5 Ceylon stations.

Oncea subtilis, Giesbr.
Oncea notopus, Giesbr.
Oncea conifera, Giesbr.
Three rarer species. O. subtilis occurred at 3 Mediterranean stations ; 0. notopus
between Port Said and Suez, and 0. conifera in the Northern Indian Ocean.

Lubbockia squillimana, Claus.
Occurred at 4 stations in the Gulf of Suez and Red Sea, and once off Minikoi.

Family: COEYC^ELLW..
Corycseus venustus, Dana.
Eighteen soecies of the genus Corycmis are included in the collection. C. venustus
was obtained in fair numbers throughout the entire voyage, occurring at 42 stations.

Corycseus rostratus, Claus.
Occurred at 5 Mediterranean stations.

Corycseus danae, Giesbr.
Taken at 22 stations, from the Mediterranean onwards.

Corycseus furcifer, Claus.
Taken at 2 Mediterranean stations, twice in the Indian Ocean, and at 5 Ceylon
stations.

Corycseus flaccus, Giesbr.
Occurred at 7 Mediterranean stations and once in the Indian Ocean.

Corycseus elongatus, Claus.
Taken once in the Mediterranean, twice in the Red Sea and once in the northern
Indian Ocean.

Corycams speciosus, Dana.
Generally distributed throughout the voyage, and taken at 5 Ceylon stations.

Corycseus lubbockii, Giesbr.
Found at 8 stations, in Mediterranean, Indian Ocean and 4 localities round Ceylon.

Corycseus carinatus, Giesbr.

Occurred 5 times, viz., Mediterranean, Gulf of Suez and Indian Ocean, off Minikoi
and south of Cheval Paar, Ceylon.

286 CEYLON PEARL OYSTER REPORT.

Corycaeus ovalis, Claus.
Taken at 11 stations in the Mediterranean, Red Sea and northern Indian Ocean.

Corycaeus obtusus, Dana.

Corycseus gibbulus, Giesbr.

Corycaeus longistilis, Dana.

Similar in range of distribution, occurring from Suez to Ceylon at 47, 41 and 16
stations respectively. C longistilis however occurred only once about Ceylon, viz.,
south of Adam's Bridge, the others being generally represented round the island.

Corycaeus concinnus, Dana.

First appeared in the Indian Ocean, where it occurred at 13 stations, and at 5 Ceylon
localities.

Corycaeus gracilicaudatus, Giesbr.
Similar in range to C. concinnus, but it first appeared in the Red Sea.

Corycaeus robustus, Giesbr.
Taken once only, in the northern Indian Ocean.

Corycaeus tenuis, Giesbr.
Occurred at 3 stations, viz., in the northern Indian Ocean, off Negombo, and at the
Cheval Paar pearl banks.

Corycaeus longicaudis, Dana.
One specimen was found at Muttuvaratu Paar, Ceylon.

Copilia mirabilis, Dana.

Found in the Mediterranean, Gulf of Suez, Red Sea, at 6 stations in the Indian
Ocean, and once at Ceylon, south-east of Cheval Paar.

Sapphirina ovatolanceolata, Dana.

Ten species of the genus Sapphirina occur in the collection, the majority being
represented at only 1 or 2 localities. >S'. ovatolanceolata was the most widely distributed,
and occurred at 12 stations, extending from the Mediterranean to the Red Sea and
Indian Ocean as far as Minikoi.

Sapphirina gastrica, Giesbr.

Occurred twice, viz., in the Red Sea, and again from Perim into the Indian Ocean.

Sapphirina ovalis, Dana.

One specimen was taken in the Indian Ocean after leaving Perim, and another south
of Adam's Bridge, Ceylon.

COPEPODA. 287

Sapphirina nigromaculata, Claus.
Occurred at 6 Indian Ocean stations, and south of Cheval Paar, Ceylon.

Sapphirina metallina, Dana.

Sapphirina salpse, Glaus.

Sapphirina auronitens, Claus.

Sapphirina bicuspidata, Giesbr.

Sapphirina intestinata, Giesbr.

Sapphirina sinuicauda, Brady.

One or two specimens of each of the above were taken in the Indian Ocean, with
the exception of S. sinuicauda, which was taken at Vankali Paar, Ceylon.

Family : ASTEEOCHEPJD M.

Asterocheres stimulans, Giesbr.

Asterocheres dentatus, Giesbr.

Asterocheres minutus, Glaus.

Several specimens belonging to each of the above species were obtained in the
general washings from Ceylon Invertebrates and also in washings from sponges
collected in the Gulf of Manaar.

Asterocheres manaarensis, n. sp. — Plate XIX., figs. 11 to 20.

Length, female 0'78 millim. ; male unknown.

Cephalothorax ovate, 6-jointed, the 5th joint very small. Abdomen 3-jointed ;
genital segment subcpiadrate, larger than the two following joints together.

Anterior antennas 20-jointed, the relative lengths of the joints being as follows :

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.
12.3.2.2.2.2.2.3.2. 5. 7. 7. 7. 7. 8. 9. 13. 4. 7. 4.

The 17th joint has a long filament, the others profusely setose.

Posterior antennas, maxilla, and maxillipeds similar to Astwopontius typicus.

Mandible consists of a long scythe-like spine, without biting teeth, and a 2-jointed
palp, the smaller apical joint bearing two terminal plumose setas.

Both branches of 1st pair of natatory legs 3-jointed ; 1st joint of outer branch has
a large posterior plumose spine ; 3rd and 4th joints of inner branch are toothed on
inner side. Inner branch of 4th pair 3-jointed, the apical joint terminating in a laro-e
serrated lanceolate spine ; the inner side of the joints toothed. The 5th pair each
consist of a ciliated oblong joint. Furca short and stout, broader than long. Two
specimens, both females, were found in the washings from Gulf of Manaar spono-es.

Asterocheres major, n. sp. — Plate XVIII., figs. 21 to 28.
Length, female 1*1 millim. ; male 1 millim.

288 CEYLON PEARL OYSTER REPORT.

Body nearly circular in outline. Cephalothoracic segment large. Anterior
antennas 20-jointed ; proportional lengths of joints : —

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.
12. 5. 4. 3. 3. 3. 3. 4. 4. 5. 4. 4. 5. 7. 7. 7. 10. 6. 4. 2.

Posterior antennas, mandible and palp, maxilla, maxilliped, and natatory legs, 1st
to 4th, nearly as in other Asterocheres. Fifth feet very narrow, about 3|- times longer
than broad, furnished with three apical setae. Abdomen 3 -jointed, about ^ the
length of the body, joints of moderate length, genital segment slightly longer than
the 2nd joint, last joint about f the length of the second. Furca very short,
about as broad as long, and only £ the length of the last abdominal joint. The
male is slightly smaller than the female, and has the anterior antenna only 17-jointed.
The genital segment of the abdomen is slightly longer than the combined lengths of
the next 2 joints.

A number of specimens in washings from material collected off Point de Galle.
This species is easily recognised by its circular body and narrow abdomen.

Asterocheres minor, n. sp. — Plate XVIIL, figs. 29 to 31.

Length, female 0*8 millim. ; male 0'7 millim.

In general appearance very like Asterocheres major, only much smaller.

Anterior antennas 20-jointed ; proportional lengths of joints : —

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.
10. 3. 3. 3. 2. 2. 2. 3. 4. 4. 3. 3. 4. 4. 5. 6. 8. 4. 5. 2.

Other appendages similar to A. major.

The distinguishing characters of this species are the difference in the proportional
lengths of the joints of the anterior antennas, the different proportional lengths of the
abdominal joints and the furca, the latter beiug about |- the length of the last
abdominal joint.

Several specimens in washings from Gulf of Manaar sponges.

Asteropontius, n. gen.

Cephalothorax roundly ovate, 5-jointed, the cephalic segment larger than the
combined lengths of the 4 following segments. Anterior antennas 18-19-jointed.
Abdomen 3-jointed.

Outer branch of posterior antennas 4-jointed, a small 1 -jointed branch springing
from the 1st joint. Maxilla 2-branched. Mandible long and narrow ; palp 1 -jointed.
Maxillipeds and natatory legs, 1st to 5th, as in Asterocheres.

Asteropontius typicus, n. sp. — Plate XIX., figs. 1 to 10.

Length, female 0"96 millim. ; male unknown.

Cephalothorax roundly ovate, about twice the length of abdomen ; genital segment

COPEPODA. 289

as long as the other 2 abdominal joints combined; tumid in centre. Furca very
short.

Anterior antennae ID-jointed, all clothed with short setose spines; the 17th carries
a long narrow filament. The proportional lengths of the joints are as follows: —

I. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 1G. 17. 18. 19.
L2. 4. 3. 3. 3. 3. 3. 4. 3. 5. 7. 7. 7. 7. 7. 8. 9. 4. 6.

Mandible long, narrow, with 5 biting teeth at apex : palp 1-jointed, with long
terminal plumose seta?. Maxilla 2-branched, the smaller one half the length and half
the width of the larger branch, both bearing long terminal plumose seta?. Maxillipeds
and 1st to 5th natatory legs as in Asterocheres ; basal joint of outer branch of
1st pair has a broad lanceolate spine on apex of outer margin.

Several specimens, all females, were found in the washings from Gulf of Manaar
sponges, and in the general washings of Invertebrates. The species bears a general
resemblance to AsterocJteres, but the ID-jointed antenna? and the 1-jointed mandible
palp separate it therefrom.

Asteropontius attenuatus, n. sp. — Plate XV1IL, tigs. 11 to 20.
Length, female 0'92 millhn. ; male unknown.

Body attenuated, very narrow in front. Cephalothoracic segment triangular in
outline, nearly twice as long as the combined lengths of the 1st, 2nd, and 3rd thoracic
segments. Anterior antenna? 18 -jointed, with a large sensory filament on the end of
the 17th joint. Proportional lengths of the joints :—

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

II. 4. 2. 2. 2. 2. 2. 3. 7. 4. 7. 7. 7. 8. 8. 10. 12. 10.

Posterior antenna?, mandible, maxilla, maxillipeds, and 1st to 4th natatory legs
nearly as in Asteropontius typicus. Fifth feet long and very narrow, about G times
longer than broad, and furnished with 3 apical seta?. Abdomen 3-jointed. Genital
segment longer than the combined length of the next 2 joints. Anterior portion
tumid. Furcal rami short, about 2^ times as long as broad, and equal to the length
of the last abdominal joint.

Two specimens were found in washings from Ceylon Invertebrates.

This species is easily distinguished from A. typicus by its attenuate form and the
long narrow 5 th feet.

Collocheres giesbrechti, n. sp. Plate XVIII, figs. 1 to 10.
Length, female 0'G7 millim. ; male unknown.

Body elongate, sub-ovate ; cephalothoracic segment with a rounded forehead and
about equal to twice the lengths of the 1st to 3rd thoracic segments combined.
Anterior antenna? 20-jointed, with a sensory filament on the end of the 18th joint.
Proportional lengths of the joints : —

1. 2. 3. 4. 5. G. 7. 8. '.). 10. 11. 12. 13. 14. 15. 1G. 17. 18. 19. 20.
12. 3. 3. 3. 3. 3. 4. 3. 4. 3. 4. 7. 5. 7. 7. 8. 8. 9. 5. 9.

2 l'

290 CEYLON PEAKL OYSTER REPORT.

Posterior antennae, mandible and palp, maxilla and maxillipeds and natatory legs
nearly as in C. graciUcauda. Fifth feet 2-jointed, 2nd joint slightly curved, long
and narrow, furnished with 2 sub-apical seta? on the outer margin, one sub-apical
seta on the inner margin and one apical seta, on each side of which there is a distinct
tooth-like projection of the foot. Abdomen narrow, 4-jointed. Genital segment
longer than the combined lengths of the 2nd, 3rd and 4th joints. Furcal rami
short and narrow, about 2i times longer than broad.

Two specimens in the washings from Ceylon Invertebrates.

This species is easily distinguished from the other members of the genus by the
lengths of the joints of the anterior antenna?, the shape of the 5th feet and the furca.

We have much pleasure in naming the new Collocheres after Dr. Giesbrecht,
whose monograph on the Naples Copepoda belonging to this peculiar family has
done much to simplify their study.

Scottocheres elongatus (T. and A. Scott).
Scottocheres longifurca, Giesbr.

Both found in washings from Ceylon dredged Invertebrates.

Lepeopsyllus, n. gen.

Body oval, thin and scale-like, composed of 4 segments. Abdomen 3-jointed and
completely covered by the last thoracic segment. Furca completely covered or only
partly covered by the same segment. The margin of the carapace is thickly lined
with papilla-like prolongations, of irregular length, which probably impart strength
to this region.

Siphon long, reaching to about the end of the last abdominal joint. Anterior
antennae 13-15-jointed. Outer branch of posterior antenna! 4-jointed ; inner branch
lone and blade-like.

Mandible rudimentary, consisting of a long hair attached to a short slender basal
joint ; palp 2-jointed, the joints long and of about equal length, the outer one covered
with minute hairs. Maxilla consists of 2 separate lobes attached to the ends of a
long basal joint. Maxillipeds nearly as in the other Asterocheridae.

Both branches of 1st to 3rd pairs of natatory legs 3-jointed; outer branch of
4th pair 3-jointed, the inner consisting of a minute knob with one hair; 5th pair
each consist of a long curved hairy appendage. Furca divergent, long and narrow".

Lepeopsyllus typicus, n. sp. — Plate XIX., tigs. 21 to 29.

Length, female l-48 millims. ; male unknown.

Anterior antenna? 15-joiuted, the proportional lengths of the joints being as follows :

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. T . , . . £1

Joint 12 bears a long nne nlament.
26. 13. 18. 5. 4. 5. 4. 4. 4. 4. 4. 5. 3. 4. 1. S

COPEPODA. 291

The other characters are the same as those of the genus. Furcal rami lone and
divergent, extending a little beyond the edge of the carapace.

One specimen, a female, was found in the Muttuvaratu pearl oyster washings.
This species has a longer and less rounded body than the succeeding one, the only
known species for which it could be mistaken. The jointing of the anterior antennas
also serves to distinguish it.

Lepeopsyllus ovalis, n. sp. — Plate XIX., figs. 30 to 33.

Length of female 1*4 millims. ; male unknown.

Carapace more rotund than in L. typicus hut otherwise very similar. Anterior
antennae 13-jointed, the proportional lengths of the joints being as follows : —

1. 2. 3. 4. 5. (3. 7. 8. 9. 10. 11. 12. 13.
21. 10. 17. 5. 4. 7." 4. 4." 7. 5. 2. 4. 2.

The other appendages are practically the same as those of L. typicus. Furca are
entirely covered by the carapace. Two specimens, both females, were found in the
general washings from dredged Invertebrates.

Besides the difference in shape of the carapace, the jointing of the anterior antennas
serves to distinguish this species from L. typicus.

Doropontius, n. gen.

Body nearly circular ; cephalic and thoracic segments produced laterally into strong
points. Abdomen of the female 3-jointed, anterior antenna? 17-jointed. Posterior
antennas as in Asterocheres manaarensis. Mandible, maxilla, maxillijjeds and
lst-4th pairs of natatory legs as in Asterocheres. Fifth pair of natatory legs
2-jointed.

Doropontius denticornis, n. sp. — Plate XX., figs. 1 to 5.

Length, female 0-9 millim. ; male unknown.

The cephalic segment shield-shaped, forming about f of the entire animal. Second
and 3rd thoracic segments have each an obtuse lateral tooth. Abdomen short;
genital segment about twice as broad as long, laterally excavated to form an
upper and a lower tooth, the latter rounded posteriorly. The 2nd and 3rd segments
together hardly equal in length to the 1st, and about twice as broad as long.
Anterior antenna 17-jointed, the proportional lengths of the joints being as follows :—
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. .12. 13. 14. 15. 16. 17.
19. 6. 13. 5. o.TToTgTg. 7T 7. 7. 8. 10. 3. 6. 2.
The lower margin of the 4th joint is prolonged into a strong pointed tooth, and the
14th joint bears a long filament. Furcal rami quadrate, rather longer than broad.
A few specimens, all females, were found in washings from Gulf of Manaar sponges

2 P 2

292 CEYLON PEARL OYSTER REPORT.

and in the general washings of Invertebrates. The pointed cephalic and thoracic
segments, the anterior antennae, and the 3-jointed abdomen are the characters which
distinguish this genus and species.

Cletopontius, n. gen.

Body broadly ovate, the cephalic segment forming about f of the entire body.

Abdomen 3-jointed. Inner branch of posterior antennae 2-jointed. Mandible
stylet-shaped, palp 1 -jointed. Maxilla and maxillipeds as in Asterocheres. First,
2nd and 3rd pairs of natatory legs 2-branched, both branches 3-jointed; 4th pair
composed of 1 branch only.

The characters of this genus do not agree in all respects with any of the known
sub-families of the Asterocheridaj, and a new sub-family may therefore be required
for its reception.

Cletopontius serratus, n. sp. — Plate XX., figs. 9 to 18.

Length, female 0"8 millim. ; male unknown.

Lateral edges of 1st and 2nd thoracic segments bluntly serrated. Abdomen small,
the genital segment being about equal in size t<> 16 of either of the 2 following joints,

Anterior antenna 18 -jointed, the proportional lengths of the joints being as follows :—
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 1 1 . 12. 13. 1 4. 15. 16. 17. 18.
28. 12. 7. 15. 6. 8. 10. 3. 6. 12. 10. 8. 8.10.10.13.14 3.

The 4th joint is faintly divided into 3, the 16th joint bears a long filament. Inner
branch of posterior antenna 2-jointed ; the apical joint less than ^ the length of the
basal joint.

The other characters as those of genus, which readily distinguish it. A few
specimens, all female, were found in the general washings of dredged Invertebrates.

Bradypontius siphonatus, Giesbr.
Found in washings from Ceylon dredged material.

Artotrogus orbicularis, Boeck.
One specimen was in the general washings from Ceylon dredged Invertebrates.

Stephopontius, n. gen.

Body sub-quadrate, a strongly marked dividing line separating the cephalic
segment from the thoracic joints ; all have rounded margins.

Abdomen of female composed of 1 joint ; that of male 3-jointed. Anterior antenna
of female 6-jointed ; the male antenna is 2-jointed, the apex forming in conjunction
with the extremity of the basal joint what appears to be a strong clasping organ.

COPEPODA. 293

Posterior antenna 1 -branched. Mandible stylet- shaped ; palp 1 -jointed. Maxilla
represented b}7 a stout plumose spine. Maxillipeds as in Asterocheres. First pair of
natatory legs each composed of two 1 -jointed branches, the outer branch very small;
2nd and 3rd pair 2-branched, both 2 -jointed ; 4th pair 1-branched, having 2 joints.
In 5th pair each consists of a lamella.

Stephopontius typicus, n. sp. — Plate XX., figs. 19 to 31.

Length, female 6'7 millims. ; male 8 millims.

Second thoracic segment in female has a terminal lateral appendage on each side ;
this is absent in male, which has a prolongation of the last thoracic segment on each
side of the abdomen. The 1 -jointed abdomen in female has a small protuberance
on each side at the genital opening. Male abdomen 3-jointed, very small.

Anterior antenna of female G-jointed, the proportional lengths being as follows : —

— The terminal joint bears a lono- filament.

13. 16. 8. 8. 7. 16. J s

Posterior antenna 4-jointed, the apical joint bearing a broad spine with wide trifid

end. Other characters as in the genus. Furcal rami very small, spherical in male :

knob-like in female. A number of specimens, both males and females, of this

very striking form were found in the general washings from dredged Invertebrates.

Its general appearance, the male anterior antennae, and the 1st, 2nd and 5th natatory

legs prevent its being mistaken for any other known species.

Family: EEGASILID^E.

Bomolochus scomberesocis, Kb.

One adult female with 2 larval forms attached to vulva was taken from the gills
of Caranx leptolepis from Aripu, Ceylon.

Bomolochus unicirrus, Richiardi.

Several specimens, male and female, were found in the gill chambers of Ampkisile
scutala, Linn., from Ceylon.

Family: CALIGID.-E.

Caligus dakari, Van Beneden.

Several specimens were taken from the mouth of Arius venosus caught in Palk Bav,
Ceylon.

Caligus diaphanus, Nordmann.

Several were found about the mouth and attached to the dorsal fin of Thereupon
pitta from Aripu, Ceylon.

294 CEYLON PEARL OYSTER REPORT.

Caligus benedeni, Bassett- Smith.

Found attached to the inner surface of operculum of Scicena diacanthus from Palk
Strait, Ceylon.

Lepeophtheirus thompsoni, Baird.

Found associated with Ccdigns dakari in the mouth of Arius venoms
from Palk Bay. Ceylon.

Family : ( !HONDRA< 'AXTHI I ).E.

Chondracanthus cornutus, Muller.

One only was taken from the gills of Cynoglossus oligolepis, from
Ceylon.

Chondracanthus cynoglottidis, n. sp. — Text, fig. 1.

Length, female 4 '65 millims. (excluding ovisacs); male unknown.
Head rounded, 2-lobed, as wide as the widest part of the body.
Body constricted for about -^ of its length, when it expands in width,
again narrowing towards the posterior end, and terminating in short
strong spines. Anterior antenna? unjointed, about 3 times as long as
broad. Posterior antennas consist of 2 gracefully curved spines. Two
pairs of lateral prolongations (rudimentary appendages), having on
under side of each a small rounded tubercle, spring from the constricted
part of the body. A pair of long wide ovisacs, equalling in length the
Fig. 1. entire animal, are attached to the posterior end.

cimoqlottidis Specimens were found attached to the nasal ccecum in Cynoglossus

brachyrhyncKus and C. brevirostris by Mr. J. Johnstone, who obtained
for us this series of 1 1 fish-parasites while examining the collection of Ceylon fishes in
the Zoological Department of Liverpool University.

Family: LERlOEOPODIDiE.
Brachiella thynni, Cuv.
Attached to gills of Chirocentrus <l<>ral>, from Palk Strait.

Brachiella merluccii, Bassett-Smith.
From grooves underneath the head of Scicena diacanthus from Palk Strait.

Anchorella uncinata, Muller.
Found under head in the folds of operculum of Gazza aquulcefoi-mis from Palk Bay.

COPEPODA. 2'J5

EXPLANATION OF PLATES.

PLATE I.

Fig. 1. Ridgcvxci/ia typica, n. gen. et a. sp., female, from left side, x 80.

2. ,, ,, last thoracic segment, from left side. x 160.

„ 3. ,, „ anterior antenna. x 123.

,, 4. ,, ,, posterior antenna. x 220.

,, 5. ,, ,, mandible and palp. x 220.

„ G. ,, ,, maxilla. x 220.

„ 7. ,, ,, 1st maxilliped. x 220.

„ 8. „ „ 2nd „ x 220.

,, 9. „ ,, 1st natatory leg. x 220.

„ 10. „ „ 2nd „ x 220.

„ 11. „ „ 4th „ x 220.

„ 12. „ „ 5th „ x 220.

„ 13. ,, ,, abdomen and furca, from above. x 53.

14. G&niropages tetmiremis, n. sp., female, from above, x 40.

„ 15. ,, ,, 5th pair of natatory legs, female. x 106.

,, 16. ,, „ right anterior antenna, male, x 53.

,, 17. ,, ,, 5th pair of natatory legs, male. x 106.

,, 18. ,, „ abdomen and furca (male), from above. x 53.

,, 19. Centrvpages dortispinatus, n. sp., female, from above, x 53.

,, 20. ,, ,, cephalic segment, from left side, x 53.

,, 21. ,, ,, basal joints of anterior antenna.1, female. x 106.

,, 22. ,, „ 5th natatory leg, female. x 106.

,, 23. ,, ,, right anterior antenna, male. x 53.

,, 24. ,, ,, 5th pair of natatory legs, male. x 106.

,, 25. ,, „ abdomen and furca (male), from above. x 53.

PLATE II.

Fig. 1. Pontellu dance, var. ceylonica, female, from above, x 32.

,, 2. „ ,, ,, rostrum. x 80.

,, 3. ., ,, ,, inner branch of 1st natatory leg. x 159.

,, 4. „ ,, ,, 5th pair of natatory legs. x 80.

,, 5. ,, ,, ,, abdomen and furca. x 53.

., 6. Labidocera kroi/eri, var. gallensis, male, 5th pair of natatory legs. x 53.

„ 7. „ „ „ last thoracic and 1st abdominal segments, x 53.

8. ., var. stylifera, male, 5th pair of natatory legs. x 53.

„ 9. „ „ last thoracie and 1st abdominal segments. x 53.

,, 10. Labuluceru pectinatu, n. sp., female, from above. x 40.

,,11. „ ,, ,, rostrum. x 106.

„ 12. „ „ ,, inner branch of 1st natatory leg. x 160.

,, 13. ,, ,, „ 5th pair of natatory legs. x 106.

,, 14. „ ,, „ abdomen and furca. x 80.

,, 15. l'onh llujisis hi ril urn iii, n. sp., female, from above. x 40.

,, 16. ,, ,, ,, rostrum. x 80.

296 CEYLON PEARL OYSTER REPORT.

Fig. 17. Ponielhpsis lierdmani, n. sp., female, 5th pair of natatory legs, x 106.

18. Metacalwnm awivilMi, Cleve, female, 5th pair of natatory legs, x 552.

„ 19. ,, ,, „ abdomen and furca. x 552.

,, 20. ., ., male, 5th pair of natatory legs. x 159.

,, 21. Psetulodiaptomus salinus, GlESBR., female, 5th natatory leg. x 159.

,. 22. ,, ,, male, 5th pair of natatory legs. x 159.

„ 23. ,, .. ,. abdomen and furca. x 159.

., 24. Pseudodiaptamiis aurivillii, Cleve, female, 5th natatory leg. x 159.

„ 25. ,, „ male, 5th pair of natatory legs. x 159.

„ 26. „ ,, „ abdomen and furca. x 159.

PLATE III.

Fig. 1. Suiuiristes inopinata, n. sp., female, from left side, x 80.

,, 2. „ ,, ,, anterior antenna. x 156.

„ 3. „ ,, ,, 1st natatory leg. x 90.

„ 4. „ „ „ 2nd „ x 120.

„ 5. „ „ „ 4th „ x 120.

„ 6. „ „ „ last abdominal segment and furca. x 60.

,, 7. ,, ,, male, apical joints of anterior antenna. x 195.

,. 8. ,, ,, female, 5th natatory leg. x 390.

,, 9. Sunaristes longipes, n. sp., female, from left side, x 80.

,, 10. ,, ,, ,, 4th natatory leg. x 120.

,,11. ,, ,, „ last abdominal segments and furca. x 60.

,, 12. Sunaristes curticaudata, a. sp., female, from left side, x 80.

,, 13. ,, ., „ anterior antenna. x 111.

,, 14. ,, „ ,, 2nd natatory leg. x 120.

„ 15. „ „ „ 3rd „ x 120.

„ 16. „ „ „ 4th „ x 120.

,, 17. ,, ,, ,, last abdominal segments and furca. x 90.

,, 18. Hevsiliodes (hdria, n. sp., male, from above. x 45.

,, 19. „ „ ,, anterior antenna. x 90.

,, 20. „ ,, ,, posterior antenna. x 180.

„ 21. ,, „ ,, mandible. x 260.

„ 22. ,, ,, ,, maxilla. x 260.

,, 23. ,, ,, ,, 1st maxilliped. x 260.

„ 24. „ „ „ 2nd „ x 90

„ 25. „ „ ,, 1st natatory leg. x 120.

„ 26. „ „ „ 4th „ x 120.

„ 27. „ „ „ 5th „ x 180.

PLATE IV.

Fig. 1. Tegastes imlhwni, n. sp., female, from right side, x 106.

,, 2. ,, ,, another female, from left side. x 159.

,, 3. „ ,, female, anterior antenna. x 195.

,, 4. ,, ,, ,, 2nd maxilliped. x 195.

„ 5. „ „ ,. 1st natatory leg. x 136.

6. „ „ „ 2nd „ x 90.

COPEPOPA.

29;

Fig. 7. Tetiasiea iuiihurni, n. sp., female, 3rd natatory lej

8.

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.

99

5th

TegaMea domumi, n. sp., female, from right side.
„ „ anterior antenna.

5th natatory leg.
Teyastes twynaini, n. sp., female, from right side.

anterior antenna.

x 60.
x 60.
x 60.
x 159.
x 390.
x 90.
x 100.
x 60.

,, ,, „ 2nd maxilliped. x 260.

5th natatory leg. x 181.
'I'lijiislrs chalmersi, n. sp., female, from left side. x 159.

,, ,, ,, anterior antenna. x 781.

„ ,, ,, 2nd maxilliped. x 320.

., ., 1st natatory leg. x 500.

„ 4th „ x 500.

„ 5th „ x 500.

PLATE V,

Fig. 1. Slenlielia brevicornis, n. sp., female, from left side, x 106.
n 2. ,, ,, ,, anterior antenna. x 368.

n 3. „ ,, ,, posterior antenna, inner branch. x 276.

„ ,, ,, mandible and palp. x 276.

,, ,, „ 2nd maxilliped. x 368.

„ ,, ,, 1st natatory leg. x 276.

„ 4th „ x 221.

„ 5th „ x 276.

„ „ ,, last abdominal segment and furca. x 159.

Slenlielia gradlicaudata, n. sp., female, from left side, x 159.

,, „ ,, anterior antenna. x 276.

,, „ ,, 1st natatory leg. x 276.

4th „ x 276.

„ 5th „ x 276.

,, ,, last abdominal segment and furca. x 159.

Slrnlirliii longicomis, n. sp., female, from left side. x 106.

,, ,, ,, anterior antenna. x 221.

,, ,, ,, 1st natatory leg. x 221.

5th „ x 221.

,, ,, ,, last abdominal segment and furca. x 101.

,, ,, male, 2nd natatory leg, inner branch, x 221.

^itVi x 2'>1

,, ,, Jill ,, ,, * &*L.

ale, from left side. x 159.
, anterior antenna. x 335.

posterior antenna, inner branch. x 552.
, mandible and palp, x 552.

1st natatory leg. x 276.
, 5th ,, x 335.

last abdominal segment and furca. x 335.
2 Q

4.

5.

6.

7.

8.

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.

Aim iru minor, a. sp., fei

298

CEYLON PEARL OYSTEK REPORT.

PLATE VI.

Fig.

l.

11

2.

11

3.

J)

4.

11

5.

11

6.

>-

11

8.

J)

9.

jj

10.

,,

11.

11

12.

11

13.

11

14.

11

15.

i)

16.

11

17.

J)

18.

n

19.

»j

20.

ii

21.

ii

22.

ii

23.

24.

Stenhelia perplem, n. sp., female, from left side, x 159.

„ ,, „ anterior antenna, x 390.

,, ,, „ 2nd maxilliped. x 530.

„ „ „ 1st natatory leg. x 260.

» 4th „ x 260.

5th „ x 260.

„ „ ,, last abdominal segment and fuica. x 260.

Stenlielia dentipes, n. sp., female, from left side, x 159.

„ ,, ,, basal joints of anterior antenna. x 260.

„ ,, ,, 2nd maxilliped. x 781.

,, „ ,, 1st natatory leg. x 390.

4th „ x 260.

„ 5th „ x 390.

„ „ ,, last abdominal segment and furca.

Ameira tenuipes, n. sp., female, from left side, x 159.

,, ,, ,, anterior antenna, x 390.

,, ,, ,, posterior antenna, inner branch. x 390.

,, ,, ,, mandible and palp. x 390.

„ ,, ,, 1st natatory leg. x 390.

„ 5th „ x 390.

Stenhelia minuta, n. sp., female, from left side, x 159.

,, ,, ,, anterior antenna, x 260.

,, ,, ,, 1st natatory leg. x 390.

„ „ „ 5th „ x 390.

PLATE VII.

Fig. 1.

o

ii -■•

„ 3.

„ 4.

„ 5.

„ 6.

,. 7.

„ 8.

,. 9-

„ 10.

„ 11.

„ 12.

„ 13.

„ 14.

„ 15.

„ 16.

„ 17.

„ 18.

., 19.

ParastenMlia lwrnelli, n. gen. et sp., female, from left side, x 106.

,, ,, ,, anterior antenna. x 260.

,, ,, „ posterior antenna. x 260.

,, ,, ,, mandible and palp, x 390.

,, ,, ,, 2nd maxilliped. x 390.

x 260.
x 195.
x 195.
x 260.
x 260.
x 106.
x 390.

1st natatory leg.

( 'eyloma aculeata, n gei

,, ,, 4th ,

,, ,, oth ,.

,, male, 2nd ,

„ ,, oth ,

et sp., female, from left side.

,, anterior antenna.

posterior antenna. x 390.
mandible and palp, x 390.
maxilla. x 260.
1st maxilliped. x 260.
2nd „ x 780.

1st natatory leg. x 260.
4th „ x 195.

COPEPODA. 299

Fig. 20. Ceylomia acuUata, n. gen. et sp., female, 5th natatory leg. x 195.
„ 21. ,, ,, ,, last abdominal segment and furea. x 90.

,, 22. ,, ,, male, 3rd natatory leg. x 195.

„ 23. „ „ „ 5th „ x 390.

PLATE VIII.

Fig. 1. Laophonle hirsuta, n. sp., female, from above, x 10G.

,, 2. „ ,, ,, anterior antenna. x 260.

,, 3. ,, ,, „ posterior antenna, inner branch, x 395.

„ 4. ,, ,, ,, mandible and palp. x .'595.

,, 5. ,, ,, ,, 2nd maxilliped. x 395.

,, G. ,, ,, ,, 1st natatory leg. x 395.

„ 7. „ „ „ 4th „ x 395.

„ 8. „ „ „ 5th „ x 260.

,, 9. Laophontella typica, n. gen. et sp., female, from above, x 106.

„ 10. „ „ „ from left side, x 106.

„ 11. ,, ,, ,, anterior antenna. x 395.

„ 12. „ „ „ 2nd maxilliped. x 395.

„ 13. ,, ,, ,, 1st natatory leg. x 260.

„ 14. „ „ „ 2nd „ x 260.

„ 15. „ „ „ 4th „ x 260.

„ 16. „ „ „ 5th „ x 260.

,, 17. Tetragonic&ps dubia, n. sp., female, from left side, x 106.

„ 18. ,, ,, „ anterior antenna. x 260.

„ 19. „ ,, „ 2nd maxilliped. x 395.

,, 20. ,, ,, ,, 1st natatory leg. x 195.

„ 21. „ „ „ 4th „ x 195.

„ 22. „ „ „ 5th „ x 260.

,, 23. Tetragoniceps minor, n. sp., female, from left side, x 159.

„ 24. „ ,, „ anterior antenna. x 520.

„ 25. ,, ,, „ 2nd maxilliped. x 780.

,, 26. ,, ,, ,, 1st natatory leg. x 260.

u.

5th ,, x 156.

„ 28. ,, ,, ,, last abdominal segment and fnrea. x 195.

PLATE IX.

Fi°\ 1. Dartylophusia dmiata, n. sp., female, from left side, x 80.

2. ., .i i> anterior antenna. x 221.

3. ,, ,, ,, posterior antenna, inner branch. x 221.

4. ,, ,, ,, mandible palp. x 221.

5. „ ,, ,, 2nd maxilliped. x 221.
0. ,, ,, ,, 1st natatory leg. x 184.
7 5tli x 221

8. ii .1 ii last abdominal segment and fnrea. x 221.

9. „ ,, male, 2nd natatory leg, inner branch. x 221.
„ 10. „ „ ,. 5th „ x 221.

2 q 2

!%

11.

JJ

12.

it

13.

?1

14.

»

15.

)l

10.

»

17.

JJ

18.

300 CEYLON PEARL OYSTER REPORT.

Dadylophuda liavel-ocki, n. sp., female, from left side, x 80.

„ „ „ anterior antenna, x 159.

„ ,, „ posterior antenna, inner branch. x 200.

„ „ ., mandible palp. x 260.

„ „ ,, 2nd maxilliped. x 260.

„ „ ,, 1st natatory leg. x 195.
5th „ x 130.

„ ,, ., last abdominal segment and furca. x 130.

„ 19. Dactyloplmsia hirsute, n. sp., female, from left side, x 80.

,, 20. ,, ,, ., anterior antenna. x 195.

„ 21. ,, ,, „ 2nd maxilliped. x 195.

„ 22. „ ,, „ 1st natatory leg. x 156.

„ 23. .. „ „ 5th „ x 156.

„ 24 ,, ,, ,, last abdominal segment and furca. x 111.

,, 25. Dactyloplmsia ceylonica, n. sp., female, from left side, x 64.

,, 26. ,. .. ,, anterior antenna. x 156.

,, 27. ,, ,, ,, 2nd maxilliped. x 156.

„ 28. ,, .. „ 1st natatory leg. x 156.

„ 29. „ „ „ 5th „ x 98.

,, 30. ,, ,, male, 1st „ inner branch. x 98.

„ 31. „ „ „ 2nd „ „ x 156.

„ 32. „ .. „ 5th .. „ x 130.

PLATE X.

Fig. 1. Dactyloplmsia Itamiltmi, n. sp., female, from left side, x 80.

,, 2. ,, „ „ anterior antenna. x 120.

,, 3. .. .. .. posterior „ x 181.

„ 4. ,, ,, ., 2nd maxilliped. x 260.

,, 5. ,, ,, ,, 1st natatory leg. x 195.

,, 6. „ „ „ 5th „ x 195.

,, 7. ,, „ ,, last abdominal segment and furca. x 181.

,, 8. Parastenlielia simili% n. sp., female, from left side, x 106.

,, 9. ,, ,, „ anterior antenna. x 260.

,, 10. ,, „ „ 2nd maxilliped. x 390.

„ 11. ,, ,, „ 1st natatory leg. x 260.

„ 12. „ „ „ 4th „ x 195.

., 13. „ ,, ,, 5th „ x 260.

,, 1 4. „ ,, ,, ■ last abdominal segments and furca. x 260.

,, 15. Stenhelia hnoxi, n. sp., female, from left side, x 106.

,, 16. ,, .. ,, anterior antenna. x 390.

,, 17. „ „ ,, 1st natatory leg. x 390.

„ 18. ,, „ „ 5th „ x 195.

,, 19. Dactyloplmsia robusta, n. sp., female, from left side, x 159.

„ 20. ,, „ „ anterior antenna. x 390.

,,21. ,, ,, „ 2nd maxilliped. x 390.

„ 22. ,, „ „ 1st natatory leg. x 260.

„ 23. „ „ „ 5th „ x 260.

,, 24. „ ,, ,, last abdominal segments and furca. x 260.

COPEPODA. 30]

PLATE XI.

Fig. 1. Dactijloplmma laiicaudata, n. sp., female, from above, x 159.

„ 2. „ „ „ anterior antenna. x 260.

„ 3. „ „ ,, posterior antenna, inner branch. x 2G0.

,, 4. „ ., „ mandible palp. x 260.

„ 5. ,, „ ,, 2nd maxilliped. x 260.

,, 6. „ ,, ,, 1st natatory leg. x 260.

„ 7. „ „ „ 4th „ x 260.

8. „ „ „ 5th „ x 260.

,, 9. Dantylophimia cemula, n. sp., female, from above, x 159.

,, 10. „ ,, ,, anterior antenna. x 390.

11. ,, ,. ,, 1st natatory leg. x 260.

„ 12. „ „ ., 5th „ x 260.

13. Dactylopkii'da platyaoma, n. sp., female, from above, x 106.

,, 14. „ „ „ anterior antenna. x 390.

„ 15. ,, ,, „ 2nd maxilliped. x 390.

,, 16. ,, ,, ,, 1st natatory leg. x 260.

„ 17. „ „ „ 4th „ x 260.

„ 18. „ „ „ 5th „ x 195.

,, 19. PseudolJialestris imbricaia, Brady, female, from left side, x 159.

„ 20. ,, „ ,, anterior antenna. x 390.

,, 21. ,, „ ,, 2nd maxilliped. x 260.

,, 22. ,, ,, ,, 1st natatory leg. x 195.

,, -"j. ,, ,, ,, otn ,, x iyo.

,, 24. ,, „ ,, last abdominal segment and fnrca. x 395.

PLATE XII.

Fig. 1. Porcellidium ftmbriatum, Claus, female, from above, x 106.

„ 2. ., „ „ anterior antenna. x 260.

„ 3. ,, ,, ,, posterior antenna, inner branch. x 260.

,, 4. „ ,, „ mandible and palp, x 195.

5. ,, ,, ,, 1st maxilliped. x 396.

„ 6. „ ,, „ 2nd ,, x 396.

,, 7. ,, ,, ,, 1st natatory leg. x 260.

., 8. „ „ „ 4th „ x 195.

„ 9. ., „ „ 5th „ x 195.

,, 10. ,, ,, „ abdomen and fnrca. x 180.

II. Porcellulium brevicrrwlahm, n. sp., female, from above, x 106.

,, 12. ,, ,, „ anterior antenna. x 260.

,, 13. „ ,, ,, 5th natatory leg. x 260.

„ 14. ,, „ „ abdomen and fnrca. x 195.

15. Poirellidium acviicmulatum, n. sp., female, from above. x 106.

„ 1 6. ,, n „ anterior antenna. x 260.

,, 17. „ ,, „ 5th natatory leg. x 195.

,, 18. „ ,, abdomen and fnrca. x 195.

19. Porcfllidium ravana;, n. sp., female, from above, x 106.

302 CEYLON PEARL OYSTER REPORT.

Fig. 20. Poresllidium ravanas, n. sp., female, anterior antenna. x 260.
,, 21. ,, ,, ,, 5th natatory leg. x 195.

,, 22. ,, „ ., abdomen and furca. x 156.

PLATE XIII.

Fig. 1. Peltidium ovale, n. sp., female, from above, x 40.

,, 2. ,, ,, „ anterior antenna. x 195.

,, 3. ,, „ ,, 2nd maxilliped. x 95.

,, 4. „ „ ,, 1st natatory leg. x 95.

„ 5. „ „ „ 4th „ x 95.

., 6. „ „ „ 5th „ x 95.

,, 7. Peltidium angulatum, n. sp., female, from above, x 53.

..8. „ ,, „ anterior antenna. x 195.

,, 9. „ ,, ,, 2nd maxilliped. x 95.

„ 10. „ „ ,, 1st natatory leg. x 95.

„ 11. „ ,, ,, 5th „ x 195.

„ 12. Peltidium speciosvm, n. sp., female, from above, x 53.

,, 13. „ ,, ,, anterior antenna. x 195.

,, 14. „ ,, ,, 2nd maxilliped. x 95.

„ 15. „ „ „ 1st natatory leg. x 120.

„ 10. „ „ „ 5th „ x 195.

,,17. ,, ,, „ a smaller form, with thinner bands. x 64

„ 18. Peltidium senatum, n. sp., female, from above, x 40.

(1 19. ,, „ „ anterior antenna. x 195.

20. „ „ „ 2nd maxilliped. x 95.

„ 21. „ „ „ 1st natatory leg. x 95.

„ 22. „ „ „ 5th „ x 95.

,, 23. Peltidium perplexum, n. sp., female, from above, x 40.

24. ,, „ ,, anterior antenna. x 156.

25 ,, ,, ,, 2nd maxilliped. x 95.

„ 26. „ „ u 1st natatory leg. x 95.

„ 27. „ .. ,. 5th „ x 195.

PLATE XIV.

Fi<* 1. Pmidanthessius maximum, n. sp., female, from above, x 27.

2. ,, ,, „ anterior antenna. x 90.

3. ,, „ ,, posterior antenna. x 90.

4 ., „ mandible and palp. x 156.

h 5. „ ., „ 1st maxilliped. x 120.

„ 6. „ „ „ 2nd „ x 90.

7. „ „ >, 1st natatory leg. x 60.

", 8. „ ,, „ 4th „ x 90.

„ 9. „ „ „ 5th „ x 90.

10. „ „ male, 2nd maxilliped. x 90.

11 ,, „ ,, abdomen and fiu ca. x 30.

„ 12. Pseudanthessius chelifer, n. sp., female, from above. x 80.

1*5 ,, ,, ,, anterior antenna, x 260.

COPEPODA. 303

Fig. 14. Pseudanthessius clwlifer, n. sp., female, posterior antenna, x 15G.

,, 15. „ ,, ,, mandible and palp. x 260.

„ 16. ,, „ ,, 1st maxilliped. x 260.

„ 17. „ „ „ 2nd „ x 260.

„ 18. ,, „ „ 4th natatory leg. x 156.

„ 19. Pseudanthessius gracilis, Claus, female, from above, x 80.

„ 20. ,, „ ,, anterior antenna. x 260.

„ 21. ,, „ „ posterior „ x 195.

„ 22. ,, ,, „ 2nd maxilliped. x 180.

,, 23. ,, ,, „ 4th natatory leg. x 195.

„ 24. Pseudanthessius concinnus, n. sp., female, from above, x 80.

,, 25. ,, ,, „ anterior antenna. x 260.

,, 26. ,, ,, ,, mandible. x 260.

„ 27. ,, ,, ,, 1st maxilliped. x 395.

„ 28. „ „ „ 2nd „ x 395.

,, 29. ,, ,, „ 1st natatory leg. x 195.

„ 30. „ „ „ 4th „ x 195.

PLATE XV.

Fig. 1. Lichomolgus gracilis, n. sp., female, from above, x 80.

,, 2. ,, ,, ,, anterior antenna. x 260.

,, 3. „ ,, ,, posterior antenna. x 260.

,,4. ,, ,, ,, mandible and palp. x 395.

,, 5. ,, ,, ,, 1st maxilliped. x 395.

„ 6. „ „ „ 2nd „ x 260.

,, 7. ,, ,, ,, 4th natatory leg. x 156.

„ 8. ,, ,, male, 2nd maxilliped. x 181.

„ 9. ,, „ ,, abdomen and furca. x 90.

,, 10. Lichomolgus ieversi, n. sp., female, from above, x 80.

,, 11. ,, ,, „ anterior antenna. x 260.

,, 12. „ ,, ,, posterior antenna. x 260.

,, 13. ,, ,, ,, mandible, x 395.

,, 14. ,, ,, „ 1st maxilliped. x 260.

,, 15. „ „ „ 2nd „ x 260.

,, 16. ,, ,, ,, 4th natatory leg. x 156.

,, 17. ,, „ male, 2nd maxilliped. x 180.

,, 18. Lichomolgus buddliensis, n. sp., female, from above, x 80.

,, 19. ,, ,, ,, anterior antenna. x 156.

„ 20. ,, ,, „ posterior antenna. x 78.

,, 21. „ ,, ,, mandible and palp. x 260.

„ 22. ,, „ ,, 1st maxilliped. x 260.

„ 23. ,, „ „ 2nd „ x 195.

,, 24. „ ,, ,, 4th natatory leg. x 156.

„ 25. Lichomolgus lankensis, n. sp., female, from above, x 80.

„ 26. ,, ,, ,, anterior antenna. x 260.

„ 27. Lichomolgus simplex, n. sp., female, from above, x 80.

» 28. ,, „ ,, anterior antenna x 260.

>, 29. ,, ,, ,, posterior antenna. x 195.

304 CEYLON PEARL OYSTER REPORT.

Fig. 30. Lichomolgus simplex, n. sp., female, mandible, x 260.

„ 31. „ „ „ 1st maxilliped. x 260.

„ 32. „ „ „ 2nd „ x 260.

„ 33. „ „ „ 4th natatory leg. x 195.

„ 34. ,, ,, male, abdomen and furca. x 90.

PLATE XVI.

Fig. 1. Paralichomvlgus curticaudutus, n. gen. et sp., female, from above, x SO.

„ 2. ,, ,, ,, .'interior antenna. x 195.

„ 3. „ ,, „ posterior antenna. x 90.

., 4. ,, ,, ,, mandible and palp. x 260.

,, 5. ,, „ ,, 1st maxilliped. x 260.

„ 6. „ „ „ 2nd „ x 260.

,, 7. ,, ,, ,, 4th natatory leg. x 195.

,, 8. Lichomolgus elegans, n. sjj., female, from above, x 53.

,, 9. ,, „ ,, anterior antenna. x 130.

,, 10. ,, ,, ,, posterior antenna. x 120.

,, 11. ,, „ „ 1st maxilliped. x 195.

„ 12. „ „ „ 2nd „ x 195.

„ 13. „ ,, ,, 4th natatory leg, inner branch. x 90.

,, 14. Lichomolgus robustus, n. sp., female, from above, x 80.

,, 15. ,, ,, ,, anterior antenna. x 156.

„ 16. ,, ,, ,, posterior antenna. x 156.

,, 17. ,, ,, ,, mandible. x 260.

„ IS. ,, ,, ,, 1st maxilliped. x 260.

„ 19. „ „ „ 2nd „ x 260.

„ 20. „ „ „ 4th natatory leg. x 195.

„ 21. Lichomolgus gigas, n. sp., female, from above, x 53.

„ 22. „ ,, ,, anterior antenna. x 98.

„ 23. „ ,, ,, posterior antenna. x 'JO.

„ 24. „ „ „ 1st maxilliped. x 260.

,, 25. „ ,, ., 4th natatory lug. x 60.

„ 26. „ ,, male, abdomen and furca. x 45.

,, 27. Lichomolgus dentipes, n. sp., female, from above, x 80.

., 28. „ ,, ,, anterior antenna. x 98.

„ 29. „ „ „ 4th natatory leg. x 195.

„ 30. „ „ „ 5th „ x 156.

PLATE XVII.

Fig. 1. Hermannellu rohusta, n. sp.. female, from above, x 80.

2. ,, ,, ,, anterior antenna. x 130.

3. ,, ,, „ posterior antenna. x 156.
,, -1. „ ,, ,, mandible. x 195.

„ 5. „ „ „ 1st maxilliped. x 195.

„ 6. „ „ „ 2nd „ x 195.

7. ,, „ ,, 1st natatory leg. x 156.

8. „ „ „ 4th „ x 156.

COPEPODA.

Fig. 9. Hcrmannella serendibim, n. sp., female, from above, x 80.

„ 10. „ ,, „ anterior antenna, x 130.

„ 11. „ „ „ posterior antenna. x 156.

„ 12. Hersiliodes leggii, n. sp., male, from above, x 54.

,, 13. ,, ,, „ anterior antenna. x 120.

,, 14. ,, „ „ posterior antenna, x 90.

„ 15. ,, ,, ,, mandible. x 2G0.

,, 16. ,, ,, ,, maxilla, x 195.

„ 17. „ „ „ 1st maxilliped. x 195.

„ 18. „ „ „ 2nd „ x 130.

,, 19. „ ,, ,, 1st natatory leg. x 90.

„ 20. „ „ „ 4th „ x 130.

„ 21. „ „ „ 5th „ x 111.

„ 22. Hersiliodes tamilensis, n. sp., female, from above, x 66.

,, 23. „ ,, ,, anterior antenna, x 120.

,, 24. ,, ,, ,, 2nd maxilliped. x 120.

„ 25. ,, ,, ,, 5th natatory leg. x 156.

305

Fig. 1.

2.
3.

4.

5.

6.

7.

8.

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
27«.
28.

PLATE XVIII.

CoUochciet giesbrechti, n. sp., female, from above, x 159.

,, „ ,, anterior antenna, x 260.

„ ,, ,, posterior antenna. x 260.

,, ,, „ mandible and palp. x 390.

,, ,, ,, maxilla, x 260.

,, ,, ,, 1st maxilliped. x 390.

„ „ „ 2nd „ x 260.

,, ,, „ 1st natatory leg. x 260.

„ „ 4th „ x 260.

„ 5th „ x 395.

Asteropontiits atlenuatus, n. gen. et sp., female, from above, x 106.

,, ,, ,, anterior antenna. x 195.

,, ,, ,, posterior antenna. x 156.

,, ,, „ mandible and palp. x 156.

,, ,, ,, maxilla. x 156.

,, ,, „ 1st maxilliped. x 260.

2nd „ x 260.

„ ,, ,, 1st natatory leg. x 195.

„ 4th „ x 195.

„ 5th „ x 260.

Astcrochcres major, n. sp., female, from above, x 80.

anterior antenna. x 156.
posterior antenna. x 195.
mandible and palp. x 195.
maxilla. x 195.
4th natatory leg. x 120.
5th „ x 130.

le, anterior antenna, x 156.
abdomen and furea. x 80.
2 R

306 CEYLON PEAEL OYSTEE EEPOET.

Fig. 29. Asterocheres minor, n. sp., female, from above, x 80.
,, 30. ,, „ ,, anterior antenna. x 195.

ii 31. ,, ,, male, abdomen and furca. x 80.

PLATE XIX.

Fig. 1. Asteropontius typicus, n. sp., female, from above, x 80.

2. ,, „ ,, anterior antenna. x 195.

3. „ ,, ,, posterior antenna. x 195.

4. „ ,. ,, mandible and palp. x 195.

5. ,, ,, ,, maxilla. x 390.
6- ,, ,, ,, 1st maxilliped. x 195.

7. „ „ „ 2nd „ x 195.

8. ,, „ ,, 1st natatory leg. x 195.
9- „ „ „ 4th „ x 195.

10. „ „ „ 5th „ x 195.

11. Asterocheres mammrensis, n. sp., female, from above, x 106.
12-

13. ,, „

14.
15-
16.
17-
IB.
19-
20.

anterior antenna. x 195.

posterior ,, x 195.

mandible and palp. x 195.

maxilla. x 195.

1st maxilliped. x 195.

2nd „ x 195.

1st natatory leg. x 195.

4th „ inner branch. x 195.

5th „ x 195.

21. Lepeopsyllus typkus, n. gen. et sp., female, from above, x 53.

22. ,, ,, n anterior antenna. x 195.

23. ,, ,, „ posterior ,, x 156.

24. „ ,, „ mandible and palp. x 156.

25. „ „ „ maxilla. x 260.

26. „ ,, n 1st maxilliped. x 90.

27. „ „ ,. 2nd „ x 90.

28. ,, ,, „ 1st natatory leg. x 111.

29. „ „ „ 4th „ x 111.

30. Lepeopsyllus ovaiis, n. sp., female, from above, x 53.

31. ,, „ ,, anterior antenna. x 195.

32. „ ,, ,, 4th natatory leg. x 111.

33. „ „ „ 5th „ x 195.

PLATE XX.

Fig. 1. Doropontius denticomis, n. gen. et sp., female, from above, x 80.

2. „ ,. ,, anterior antenna. x 195.

3. „ ,. ,, 1st maxilliped. x 90.
4- „ „ „ 2nd „ x 90.

5. ,, „ „ 1st natatory leg. x 195.

6. Pwalichomolgus longkaudoMs, n. sp., female, from above, x 106.

7. „ ,, ,, anterior antenna. x 195.

8. ,, ,, „ 4th natatory leg. x 195.

COPEPODA.

307

Fig. 9. Cleiopontiiti

10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
•20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.

Stepkoponti

serratus, n. gen. et sp., female, from above. x 80.

„ „ anterior antenna, x 260.

,, posterior antenna. x 260.
„ ,, mandible and palp, x 195.

,, ,, maxilla. x 195.

„ ,, 1st maxilliped. x 195.

„ ,, 1st natatory leg. x 195.

„ 3rd ,, x 195.

4th „ x 390.

„ 5th „ x 260.

tyipicus, n. gen. et sp., female, from above. x 80.
,, male ,, x 80.

,, female, anterior antenna. x 520.

,, male „ x 195.

,, female, posterior antenna, x 260.

,, ,, mandible and palp. x 260.

,, ,, maxilla. x 395.

,, ,, 1st maxilliped. x 195.

2nd „ x 195.

,, ,, 1st natatory leg. x 395.

„ 2nd „ x 260.

„ 4th „ x 260.

5th „ x 156.

It is with deep sorrow that I have to record the sudden death of my

friend and fellow-worker, the senior author of this Report, just as his last

sheets were passing through the press, and too late for any change to be

made elsewhere in this volume. Mr. Isaac Thompson's many scientific

friends, who have known and appreciated his work on the Copepoda,

will share the feelings of regret which Mr. Andrew Scott, the joint-author,

and I desire to express that this Report should have proved to be his last

piece of scient ific work.

W. A. H.

LONDON :

HARRISON AND SONS, PRINTERS IN ORDINARY TO HIS MAJESTY,

ST. MARTIN'S LANE.

CEYLON .PEARL OYST1

Anure-v

Fjgs.1-13, RmcEWAYi i lorages tenuikemi 19 25 bntropagi

CEYLON PEARL OYSTER REPORT

EPODA, PLATE II

&

Andrew 5cou dd

1-5. Pi ri-.i.i.A da . . . . . , Figs. 6 7, Labidocera kroyeri «« 5j([£.v5,5,
Figs 8.9, Labidocera i\khm;r],wb.5(wotm , > LO-14, Lai ra pectinata .
Figs, ltf-20, Metacai.anij.s aurivillii, eievf . Figs. 21-23, Pseudodiaptomu; salinus, Figs. 24 26 Pseudodiaptomus . .■

CEYLl iN PEARL - iYSTER REP0R1

"

Figs 1-8, Sunaristes inopinata. Figs. 9-11, Sunaristes longipes.
Figs. 12-17, Sunaristes curticaudata Figs. 18-27, Her siliodes dubia

CEYLON PEARL OYSTER REF0R1

!PODA PLATE IV

■

■

Figs. 1-9,Tegastes imthurni
Figs. 13-16, Tegastes twynami .

Figs LO-12, Tegastes donnani.

Figs. 17-22, Tegastes chalmersi.

CEYLON PEARL OYSTER REPORT

ropEPODA. PLAT!

Andrew Scott, del.

Figs. 1-9, Stenhelta brevicornis. FiGS.10-la data.

Figs. 16-22, Stenhelta longicornis. Figs^ kia minor.

CEYLON PEARL OYSTER REPORT

EPODA. PLAT]

Andrew ScoU, dd -

Figs 1-7, Stenheua perplexa . 8-14, S:.

Figs. 15-20, Ameira tenuipes. Figs 21-24, Stenheua minuta.

CEYLON PEARL OYSTER REPORT

OOPEPODA. PLAT! II

Andrew Scott, del

Ml-..*':, fi Lrjfc.ne.L.th Ed.nr

Figs. 1-10, Parastenhelia hornelli Figs. 11-23. Ceylonia aculeata.

CEYLON PEARL OYSTER REPORT

COPEPODA PLATE Vlll.

Andrew Sc jtt del

N'F<trlan» L.'E' ■

Figs lr.8, Laophonte hirsuta.
Figs.17-22, Tetragoniceps dubia.

Figs. 9Tt',. Laophonteixa typica
Figs. 23-28, i oniceps MrNOR.

CEYLON PEARL OYSTER REPl i

6

COPEPODA E IX.

.

Fig 1-10, Dactyi.ophusia dentata.
Figs. 19-24, Dactylophusia hirsuta.

Figs. 11-18, Dactylophusia n >v elocki
Figs ': iPhusia ceyli

CEYLON PEARL OYSTER REPORT

('.( (PEPODA, PLATE X.

ndrew Scott ,del

. ms 1-7, Dactylophusia hamilioni. Figs. 8-14, Parastenhelia similis.

Figs. 15-18, Stenheua knoxi . Figs. 19-24, Dactylophusia robusta.

KTartana 1

CEYLON PEARL OYSTER REPORT.

:|- PLATE X!

TVm™l%nmn|rmi^

Andrew Scott, del.

Figs. 1-8, Dactylophusia laticaudata.
Figs 13-18. Dactylophusia platysoma.

I lgs 9 12 Dactylophusia .-i-.mui.a

Figs.19-24, Pseud othalestris iMBRtcATA,fi<Mor.

M f.irl*.n« ,'-. Erslane Lil

CEYLON PEARL OYSTER REPi

- OPEPODA PLATE _X1I.

Andrew

M'Farlaite i Krskine I i

Figs. 1-10. Porcellidium fimbhiatum.Claus. Figs II 14. ( i idium brevicaudatum
Figs. 15-18, Porcellidium acuticaudatum. Figs.19-22,Porcellidium ravan^e .

CEYLON PEARL OYSTER REPORT

COPEPODA, PLATE Xffl.

Andrew 5cott.de!

M'Fitlajoe LEuhac.Lith.Edin*

Tigs 1-6. Peltidium ovale Figs.7-11, Peltidium angulatum

Figs 12-17 Peltidium speciosum Figs 18-22. Peltidium serratum. Figs. 23-27, Peltidium pebplexum

HYI.GN PEARL OYSTER REPORT

IDA, PLATE XIV.

Andrew Scott, del

FlGS.1-11, PSEUDANTHESSIUS MAXIMUS . FlGS . 12~18, PSEUDANTHESSIUS CHELIFER..

Figs. 19-23, Pseudanthessius gracilis tCi*us. Figs 24-30, Pseudanthessius concinnus.

M'FivUnr .' I

CEYLON PEARL OYSTER REPORT

COPEPODA PLATE XV.

i t >

18.

-

C7

21.

12.

16.

A

22.

25

TO 20.

24.

Andrew 3cott Bel.

FlGS.1-9, LlCHOMOLGUS GRACILIS FlG5. 10-17. LlCHOMOLGUS IEVERSI. WF«i™ *S.*i«.lia.M«

Figs. 18-24, Lichomolgus buddhensis. Tigs. 25,26, Lichomolgus lankensis. Figs. 27-34, Lichomolgus simplex.

CEYLON PEARL OYSTER REPORT

COPEPODA, PLATE XVI.

18.

16.

1 ,

■L

21

"

X 19.

12

10

11

27.

ZQ.

.

\

22.

Figs i-7, Pakalichomolgus curticaudatus. Figs. 8-13, Lichomolgus elegaks. ^"^ "MVi"-liatEa"

Figs. 14-20. Lichomolgus robustus. Figs -L26. Lichomolgus gigas. Figs. 27-30. Ltchomolgus dentipes

CEYLON PEARL OYSTER REPOR'J

COPEPODA. PLATE XVII.

Andrew 5coct, del

tiGS.1-8. EIekmannella robusta.
nos. 12-21, Hkrsiliodes lkg-gii

1 19.

Figs. 9-11, Hermannella serendibica.
Figs. 22-25, Hersiliodes tamit.ensis.

M'liiline AErsJ-ine Litkldio.*

CEYLON PEARL OYSTER REPORT.

COPEPODA, PLATE XVIII

Andrew ocott del.

■

Figs. L— 10, Collooheres gibsbubchi i. Figs 1L-20,Asteropontius attenuatus.
Figs 2] -28, Asterocheres ma.jor Figs 29-31, Asterocheres minor .

CliYLON RHARL OYSTER R I- PORT

COP1-PODA. PLATE XTX.

Figs. 1-10, Astergpontius typicus.
Figs. 21-29. Lepeopsyllus typicus.

Figs. 11-20. Asterochkres manaarensis.
Figs 30-33, Lepeopsyllus ovalis .

CEYLON PEARL OYSTER REPORT

COPEPODA, PLATE XX.

An<W Scott.del

Figs 1-5 Dohopontius denticornis. Figs. 6-8, Parauchomolgus longicaudatus .
Figs. 9-18, Cletopontius sehratus. Figs. 19-31, Stephopontius typicus.

MBL.-WHOI LIBRARY

mini

WH IflTU X

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