HARVARD UNIVERSITY. Li BRAY OF THE MUSEUM OF COMPARATIVE ZOOLOGY. \QYySd. GIFT OF ALEXANDEK AGASSIZ; nae seals BAAR desir Pa aa ee 8 (aie: er ri < " a Akie ale roy SL he = 9 oe ae a ee Doe o> aa ee % ov . I GOVERNMENT CENTRAL MUSEUM, MADRAS. | 733 —— ON THE PEARL AND CHANK FISHERIES AND | MARINE FAUNA OF THE GULF OF MANAAR, BY ~ EDGAR THURSTON, c.m.zs., &c.; SUPERINTENDENT, GOVERNMENT CENTRAL MUSEUM. MADRAS: _ ; . PRINTED BY THE SUPERINTENDENT, GOVT. PRESS. a [Patcr, Re. 1-4-0.} “1890. Tae hee oe Ae ene i ys ee Pas >=. ‘ i, at ee ee re a a Ny ERE te CO ae YE OL0OS SOU CU EIN BOOTREN AO} outa bel mae . Pe goers MED POA ih 7 Oe ee ee teen See os PR stn altwrion Se a me ee el ak red eet) and on ” ‘ : oa ze ; AAD en et ES Laon ol May tl gird 1 AR hated GOVERNMENT CENTRAL MUSEUM, MADRAS. NO TERS ON THE PEARL AND CHANK FISHERIES AND MARINE FAUNA OF THE GULF OF MANAAR. BY EDGAR THURSTON, c.m.zs., &c., SUPERINTENDENT, GOVERNMENT CENTRAL MUSEUM. C, MADRAS: | PRINTED BY THE SUPERINTENDENT, GOVT. PRESS. — [Pricz, Re. 1-4-0. ] JT 1890. a. i ; ( oedy Pee ‘ . ¥ . Ge elk i & att - {J oF | | riko We . > - » ‘ ie ul a = 4 P " VOY a aad f Re * oy! i % ‘d $ f \ ye ne (/I.—TUTICORIN PEARL FISHERY. vI1.—PEARLS OF MYTILUS AND PLACUNA., -/JIL.—TUTICORIN CHANK FISHERY. ‘IV.—CEYLON PEARL FISHERY. * V.—RAMESVARAM ISLAND. ‘VI—MARINE FAUNA OF THE GULF OF MANAAR. ‘VII.—INSPECTION OF CEYLON PEARL BANKS. ‘* Know you, perchance, how that poor formless wretch— The Oyster—gems his shallow moonlit chalice ? Where the shell irks him, or the sea-sand frets, This lovely lustre on his grief.’’ Edwin Arnold. ° I.--THE TUTICORIN PEARL FISHERY. Tuticorin, the “ scattered town,” situated on the south- west coast of the Gulf of Manaar, from which the Madras Government pearl fishery is conducted, is, according to Sir Edwin Arnold,' “ a sandy maritime little place, which fishes a few pearls, produces and sells the great pink conch shells, exports rice and baskets, and is surrounded on the landside by a wilderness of cocoa and palmyra palms.” Summed up in these few words, Tuticorin does not appear the important place which, in spite of its lowly appearance when viewed from the sea and the apparent torpor which reveals itself to the casual visitor, it is in reality, not only as a medium of communication between Tinnevelly and Ceylon, to and from which hosts of coolies are transported in the course of every year, but as being an important mercantile centre for. the shipment of 'l'innevelly cotton, jaggery, onions, chillies, &e. With respect to the shipment of jaggery, I was told, during a recent visit to Tuticorin, that, during the seasons at which jelly-fish abound in the muddy surface water of the Tuticorin harbour, so great is the dread of their sting, that coolies, engaged in carrying loads of palmyra jaggery on their heads through the shallow water to the cargo boats, have been known to refuse to enter the water until a track, free from jelly-fish, was cleared for them by two canoes dragging a net between them. Tuticorin is, indeed, ‘‘ an abominable place to land at,” and it isunfortunate that it is ordained by nature that large vessels shall not approach nearer to the shore than a distance of six miles or thereabouts, being compelled, with due regard for their safety, to lie at anchor outside Hare Island, one of Bare 1 India Re-visited, 1887, 6 a number of coral-girt islands in the neighbourhood, where hares and partridges may be shot, and sluggish Holuthurians captured in abundance at low tide as they lie impassive on the sandy shore, which is strewed with broken coral frag- ments, detached by wave-action from the neighbouring reef, and riddled with the burrows of nimble Ocypods (0. macrocera and O. ceratophthalma.) The habits of the latter species of crustacean are well described by Sir J. Emerson Tennent, who writes! :— “ The ocypode burrows in the dry soil, making deep excava- tions, bringing up literally armfuls of sand, which, with a spring in the air, and employing its other limbs, it jerks far from its burrows, distributing it in a circle to the distance of several feet. So inconvenient are the operations of these industrious pests that men are kept constantly employed at Colombo in filling up the holes formed by them on the surface of the Galle face. This, the only equestrian promenade of the capital, is so infested by these active little creatures that accidents often occur through horses stumbling in their troublesome excavations.” Not far from the north end of the town of Tuticorin, on the sandy shore, are the kilns, in which corals, coarse mollusc shells (Ostraea, Venus, Cardium, &e.), and melobesian nodules (calcareous alge) are burned and converted into chundém,” t.e., prepared lime used for building purposes, and by natives for chewing with betel. A native informs me that in the Bombay and Bengal Presidencies and in the North-Western Provinces pearls are bought by wealthy natives to be used instead of chundm with the betel. In India relations and friends put some rice into the mouth of the dead before cremation, but in China seed pearls are used for the same purpose. During my visit to Tuticorin in. 1887, I used to watch, almost daily, grand, massive blocks of Porites, Astrea and various species of other stony coral genera, being brought in canoes from the reefs and thrown into the ground to form the foundation of the new cotton mills, which, in consequence, bear the name of the Coral Mills. Lecturing at the Royal Institution * on the ‘Structure, Origin, and Distribution of Coral Reefs and Islands,” 1 Sketches of the Natural History of Ceylon, 1861. 2 The familiar house frog (Rhacophorus maculatus) of Madras is popularly known as the ‘‘chunam frog’”’ from its habit of sticking on to the chunam walls of dwelling houses. 3 Friday, March 16, 1888, 7 Mr. John Murray stated that “if we except Bermuda and one or two other outlying reefs where the temperature may occasionally fall to 66° Fahr. or 64° Fahr., it may be said that reefs are never found where the surface temperature of the water, at any time of the year, sinks below 70° Fahr., and where the annual range is greater than 12° Fahr. In typical coral reef regions, however, the temperature is higher and the range much less.” No regular series of records of the temperature of the water in the coral-bearing Gulf of Manaar has as yet been made. The surface temperature, which I recorded from time to time during my visit to Ramésvaram island in the latter half of July 1888, varied from 79° Fahr. to 91° Fahr. between the hours of 7 a.m. and 6 p.m. The following table shows the temperature range of Tuticorin during the year 1887, the readings being taken in the shade at 10 a.m. and 4 p.m. :— Range. Min. Max. January “i 9° 75° 84° February ee 6° 78° 84° March a 9° 80°~. 89° April : 12° 79° = 91° May 180"! se Bagge June a 86° 95° July 10° = 86°— «6° August ee it hs 84° 95° September . 7 85° 94° October 6° 80° 86° November .. “K Ae or a 79° 86° December... . ee 75° 86° Tuticorin has been celebrated for its pearl fishery from a remote date, and, as regards comparatively modern times, Friar Jordanus, a missionary bishop, who visited India about the year 1330, tells us that as many as 8,000 boats were then engaged in the pearl fisheries of Tinnevelly and. Ceylon. In more recent times the fishery has been conducted, successively, by the Portuguese, the Dutch, and the English. The following excellent description by Martin of the pearl fishery in the year 1700, during the Dutch occupation of Tuticorin, shows that the method of fishing adopted at that time agrees, in its essential characters, with that which is in vogue at the present day :— ‘In the early part of the year the Dutch sent out ten or twelve vessels in different directions to test the localities in which 1 Streeter, Pearls and Pearling Life, 1886. 8 it appeared desirable that the fishery of the year should be carried on; and from each vessel a few divers were let down who brought up each a few thousand oysters, which were heaped upon the shore in separate heaps of a thousand each, opened, and exam-~- ined. If the pearls found in each heap were found by the appraisers to be worth an écw or more, the beds from which the oysters were taken were held to be capable of yielding a rich harvest ; if they were worth no more than thirty sous, the beds were considered .unlikely to yield a profit over and above the expense of working them. As soon as the testing was com- pleted it was publicly announced either that there would or that there would not be a fishery that year. In the former case enormous crowds of people assembled on the coast on the day appointed for the commencement of the fishery; traders came there with wares of all kinds; the roadstead was crowded with shipping; drums were beaten, and muskets fired; and everywhere the greatest excitement prevailed until the Dutch Commissioners arrived from Colombo with great pomp and ordered the proceedings to be opened with a salute of cannon. Immediately afterwards the fishing vessels all weighed anchor and stood out to sea, preceded by two large Dutch sloops, which in due time drew off to the right and left and marked the limits of the fishery, and when each vessel reached its place, half of its complement of divers plunged into the sea, each with a heavy stone tied to his feet to make him sink rapidly, and furnished with a sack into which to put his oysters, and having a rope tied round his body, the end of which was passed round a pulley and held by some of the boatmen. Thus equipped, the diver plunged in, and on reaching the bottom, filled his sack with oysters until his breath failed, when he pulled a string with which he was provided, and, the signal being perceived by the boatmen above, he was forthwith hauled up by the rope, together with his sack of oysters. No artificial appliances of any kind were used to enable the men to stay under water for long periods; they were accustomed to the work almost from infancy, and consequently did it easily and well. Some were more skilful and lasting than others, and it was usual to pay them in proportion to their powers, a practice which led to much emulation and occasionally to fatal results. Anxious to outdo all his fellows, a diver would sometimes persist in collecting until he was too weak to pull the string, and would be drawn up at last half or quite drowned, and very often a greedy man would attack and rob a successful neigh- bour under water; and instances were known in which divers who had been thus treated took down knives, and murdered their plunderers at the bottom of the sea. As soon as all the first set of divers had come up, and their takings had been examined and thrown into the hold, the second set went down. After an interval, the first set dived again, and after them the second ; and so on turn by turn. The work was very exhaust- 9 ing, and the strongest man could not dive oftener than seven or eight times ina day, so that the day’s diving was finished always before noon. ‘The diving over, the vessels returned to the coast and discharged their cargoes ; and the oysters were all thrown into a kind of park, and left for two or three days, at the end of which they opened and disclosed their treasures. The pearls, having been extracted from the shells and carefully washed, were placed in a metal receptacle containing some five or six colanders of graduated sizes, which were fitted one into another so as to leave a space between the bottoms of every two, and were pierced with holes of varying sizes, that which had the largest holes being the topmost colander, and that which had the smallest being the undermost. When dropped into colander No. 1, all but the very finest pearls fell through into No. 2, and most of them passed into Nos. 3, 4, and 5; whilst the smallest of all, the seeds, were strained off into the re- ceptacle at the bottom. When all had-staid in their proper colanders, they were classified and valued accordingly. The largest or those of the first class were the most valuable, and it 1s expressly stated in the letter from which this information is extracted that the value of any given pearl was appraised almost exclusively with reference to its size, and was held to be affected but little by its shape and lustre. The valuation over, the Dutch generally bought the finest pearls. They considered that they had a rigbt of pre-emption. At the same time they did not compel individuals to sell if unwilling. All the pearls taken on the first day belonged by express reser- vation to the King or to the Sétupati according as the place of their taking lay off the coasts of the one or the other. The Dutch did not, as was often asserted, claim the pearls taken on the second day. They had other and more certain modes of making profit, of which the very best was to bring plenty of cash into a market where cash was not very plentiful, and so enable themselves to purchase at very easy prices. The amount of oysters found in different years varied infinitely. Some years the divers had only to pick up as fast as they were able and as long as they could keep under water; in others they could only find a few here and there. In 1700 the testing was most encouraging, and an unusually large number of boat-owners took out licenses to fish ; but the season proved most disastrous. Only a few thousands were taken on the first day by all the divers together, and a day or two afterwards not a single oyster could be found. It was supposed by many that strong under- currents had suddenly set in owing to some unknown cause. Whatever the cause, the results of the failure were most ruinous. Several merchants had advanced large sums of money to the boat-owners on speculation, which were, of course, lost. The boat-owners had in like manner advanced money to the divers and others, and they also lost their money.” B 10 In the present century the following fisheries have taken place :— 1629) 8 ee ca te - PEO £13,000 1830 se i ar Le Ty £10,000 1860-62 ae oe os . do. Rs. 379,297 1889 ee ee ee 5) EMO fey, wo ees As to the cause of the failure of the pearl oysters to reach maturity on the banks in large numbers, in recent times, except after long intervals, I, for my part, confess my igno- rance. Whether the baneful influence of the mollusea known - locally as stran (Modiola, sp.) and killikay (Avicula, sp.), the ravages of rays (Trygon, &c.) and file-fishes (Balistes), poaching, the deepening of the Pamban Channel, or currents are responsible for the non-production of an abundant crop of adult pearl-producing oysters during more than a quarter of a century, it would be impossible to decide, until our knowledge of the conditions under which the pearl oysters live is much more precise than it is at present. The argument that the failure of the pearl fishery is due to poaching is, from time to time, brought forward; but, as Mr. H. 8S. Thomas wisely and characteristically remarks ! “* the whole system of the fishery has been carefully arranged, so that everyone in any way connected with it has a personal stake in preventing poaching, and oyster poaching is not a thing that can be done in the night; it must be carried out in broad daylight ; and, to be worth doing at all, it must be done on a large scale. Ten thousand oysters cannot be put in one’s pocket like a rabbit, nor are there express trains and game-shops to take them. Every single oyster has to be manipulated, and it is only the few best that can be felt at once with the finger, and the usual way is to allow the oyster to rot and wash away from the pearl. Oysters could not be consigned fresh in boxes or hampers by rail to distant confederates; they could not even be landed without its becoming known ; and, if known, every one is interested in informing the Government officer and stopping poaching.” I cannot, however, refrain from quoting the following touching description of an ideal poach in a recent pamphlet :— ‘“Mutukuruppan and Kallymuttu are two fishermen brothers: they start out after their cold rice, ostentatiously to _ 1 Vide Report on Pearl Fisheries and Chank Fisheries, 1884, by the Hon. ‘Mr. H. S. Thomas, il get their lines ready in their canoe, and paddle away to their fishing ground ; there they drop their stone anchor: presently one observes that it is warm and he would like a bathe; over the side he goes down by his mooring rope to see what the bottom is like. He brings up a handful of oysters and gives them to Thamby; then Thamby thinks he would like a bathe, and he goes down also, and bring’s up a fist full. When they are tired they get back inte the canoe and open their spoils, taking out what pearls they can find, and pitching the shells back into the sea. This sort of thing goes on day after day and year aiter year up and down the coast, and this will partially account for the dead shells so often found on the banks. Is it to be wondered at that oysters take alarm at this constant invasion of their domain and naturally seek some other place of rest ?”’ Far more prejudicial to the welfare of the oysters than an occasional raid upon them by a stray Mutukurupam or Kallymuttu is, in all probability, the little molluse, stan, which clusters in dense masses over large areas of the sea bottom, spreading over the surface of coral blocks, smother- ing and crowding out the recently deposited and delicate young of the oyster. Time after time there is, in the care- fully kept records of the Superintendent of the Pearl Banks, in one year a note of the presence of young oysters, either pure or mixed with séran and mud or weed, while, at the next time of examination, generally in the following year, the oysters had disappeared, and the széran remained. A few examples will suffice to make this point clear :— Devi Par'—6% to 74 fathoms. May 1881. Young oysters mixed with sooram’ and mud. », 1882. Sooram. Permandu Par—6 to 6} fathoms. May 1880. A few oysters of one year age. », 1881. Young oysters mixed with sooram and mud. », 1882. Sooram. Athombadu Par—7? to 9 fathoms. May 1880. Covered with sooram. », 1881. Large number of oysters of one year age, with sooram in some places and covered with weeds. », 1882. No oysters ; sooram in some places. The bank, which was fished during the recent fishery, is situated about 10 miles east of Tuticorin, and known as the 1 Par or paar = bank. * Sooram = suran, 12 Tholayiram Par, the condition of which, as regards oyster supply, since the year 1860, is shown by the following extract from the records :— April 1860. Plenty of oysters 33 years old. Nov. 1861. Oysters scarce ; nearly all gone. April 1863. Sooram and killikay with some young oysters. Noy. 1865. April 1866. ,, 1867. > Blank. Noy. -.,; April 1869. j Mar. 1871. Five oysters with a quantity of sooram. Feb. 1872. Five oysters of 3 years age found. May 1873. Three oysters found. Jan. 1875. Three oysters of 2 years age found. Mar. 1876. North part blank. April 1877. South part blank. », 1878. Thickly stocked with oysters of 1 year age. *{ Blank. », 1881. Some oysters of 1 year mixed with killikay. ,, 1882. No living oysters; dead shells and sooram. April 1883. Three oysters found. - Mar 1884. Plenty of oysters of one year age; clean and healthy. From 1884 the bank was carefully watched, and the growth of the oysters continued steadily, unchecked by adverse conditions, as the following figures show :— (March 1884 weighed 1 oz. 33 October 9 ” ray March 1885 -c., 63 ,, October Pos - Yas 10 shells lifted.< April 1886 __,, 72 5, November ,, * a March 1887). 55 102°,, October i ‘5 L324; November 1888 __,, 15 ,, In November 1888 15,000 oysters were lifted and their product valued by expert pearl merchants at Rs, 206-13-9, t.e., Rs. 18-12-8 per thousand! as shown by the following copy of the statement of valuation :— 1 The product of 12,000 oysters lifted from the Ceylon pearl bank, the fishing of which took place synchronously with that of the Tuticorin bank, in November 1888 was valued at Rs. 122. A further sample of 12,650 oysters, lifted in February 1889, was valued at Rs. 142, 13 8 ZL St | ** saoqgsho Qoo‘'T rod oSvisay 6 SI 902| °° T1890], te: Ha i le ia g a eae ey fon ee |e" qreed [peas TORE AS ae 9° .9' OL |-G-os0E |S art se PT ay ae Fey Kee ** 9180] 000‘T ‘op, aed OG: Pbcers 0! “Viecr alee: ral i ral aM ** 51 008 Mak eg 5") 009 oh le > & D8 10. 19d Oalaeee Ay aauly (ee we es pb i |" tien oo TELUS ‘op G eeee 0 0 I} 0 0 L 8 ee 8 oe ee ee ee ee ee [Psi ‘op OL ee ee 9 i G 9 L G te se te oe ee oe eo oe 0d 49 | °° | oze/r9 ** | 00% ‘suposed ris ZZ eg Ol Op eee Om One: * I iH ye 068/31 gid 002 NATPe A £9 0-1) OSBIB LT 1008 “Op)- Gu} = O10 | &. OL 0: | BET o miele be 7. 2 0e 8 ie: ** Tepoyy ‘op 6 |0 010 |0 O10 | & gis et a ay So BOG is ees, “op Mie Pik. Om py eae ene x “11 °* | oze/gp 9 Co aecice nddyey “Op: Oh ieO> Oey 0 Oe Poa eS oot “* | O¢E/9e I Ope es poanan yy ‘sepoSded avys gz] 0 ¢ Sh|0 & &F | tt Bh 3t ** | 0¢e/seT 0G ee aes a oV¥ “st ‘ds Vie Sa ad Pile | Be a 1 oa ee ee eee Ble 2 ag 2 ® ; q = a a “nAsyg 7 ) ‘ASuwley 19g “NAIYO 19g i i ‘on[BA ul 2, | ‘worydrs0seq T°40O.L Aqrquene eS TPIOL ; 14 It may not be out of place to elucidate the meaning of some of the terms used in the above statement, and I cannot do better than quote from the excellent article on the Pearl Fisheries of Ceylon by Mr. G. Vane, C.M.G., who writes as follows! :— ‘‘ Sorting and sizing the pearls into ten different sizes, from the largest to the smallest, is done by passing them through ten brass sieves of 20, 30, 50, 80, 100, 200, 400, 600, 800, and 1,000 holes:....°. ; each of the ten sizes may include some of every class _ of pearls; the 20 to 80 and 100 may each have the éni, anatari, and kallipt kiads, and this necessitates the operation of classing, which requires great judgment on the part of the valuers. ‘Perfection in pearls consists in shape and lustre, viz., sphericity and a silvery brightness, free from any discolouration ; and, according as the pearls possess these essentials, the valuers assign their appropriate class, namely,— «© Ani a .. Perfect in sphericity and lustre. “ Anatari .. e» Followers or companions, but failing somewhat in point of sphericity or lustre. ‘ Masanka .. .. Imperfect, failing in both points, especi- ally in brilliancy of colour. “Kallipai .. .. Failing still more in both points. of el ce het .. A double pearl, sometimes Ani. ‘“« Pisal a .. Misshapen, clustered, more than two to each other. ‘* Madanku .. Folded or bent pearls. “ Vadivu ..; .. Beauty of several sizes and classes. “ Tal oe .. Small pearls of 800 to 1,000 size. ‘The pearls having been thus sized and classed, each class is weighed and recorded in kalafchu (kalungy) and maachddi (manjaday). “ The halanchu is a brass weight equal, it is said, to 67 grains Troy. The manchddi is a small red berry*; each berry, when full sized, is of nearly, or exactly the same weight; they are reckoned at twenty to the kalafichu. ‘‘The weights being ascertained, the valuation is then fixed to each pearl class or set of pearls according to the respective sizes and classes : the inferior qualities solely according to weight in kalaichu and maiichadi; the superior éf7, anatari, and vadivu are not valued only by weight, but at so much per chevo of their weight, this chevo being the native or pearl valuer’s mode of 1 Journal, Ceylon Branch, Royal Asiatic Society, 1887, vol. X, No. 34. Paper read at the Conference Meeting of the Colonial and Indian Exhibition, October 6, 1886. 2 The seed of Abrus precatorius. 15 assigning the proper value by weight to a valuable article of small weight, form and colour also considered.” The pearls of commerce are, of course, for the most part those which are formed within the soft tissues of the animal, and not the irregular pearly excrescences (oddumutta) which are found as outgrowths of the nacreous layer of the shell, frequently at the point of insertion of the adductor muscle. The nacreous layer of the Gulf of Manaar pearl oyster shell is very thin and of hardly any commercial value, the shells, after the extraction of the pearls by the process of decom- position, being used mainly in the manufacture of chun4m. As regards the cause of the formation of pearls, concern- ing which many theories have been hazarded, the most prevalent idea being that. they are a “ morbid secretion ” produced as the result of disease, I may quote from the excellent ‘“ Guide to the Shell and Starfish Galleries in the British Museum (Natural History,)”! which tells us that some small foreign body, which has accidentally penetrated under the mantle and irritates the animal, is covered with successive concentric layers of nacre, thus attaining some- times, but rarely, the size of a small filbert. The nacre is ‘generally of the well-known pearly-white colour, very rarely dark, and occasionally almost black.? The effort of the animal to get rid of the irritation caused by a foreign sub- stance between its valves, by covering it over with nacre, and thus converting it into a pearl, is strikingly illustrated by two specimens in which, in the one case, an entire fish, and, in the other, a small crab has been so enclosed. According to Streeter (op. cit.) the nucleus of the pearl may be either a grain of sand, the frustule of a diatom, a minute parasite, or one of the ova of the oysters, thin layers of carbonate of lime being deposited around the object concentrically, like the successive skins of an onion, until it is encysted. Writing in 18593 as to what may be termed the worm theory of pearl formation, Dr. Kelaart stated that “ as this report may fall into the hands of scientific men, I shall merely mention here that Monsieur Humbert, a Swiss Zoologist, has, by his own observations at the last pearl 1 Printed by order of the Trustees, 1888. 2 Among the pearls from the samples lifted at Tuticorin in November 1888 there is one dumb-bell shaped specimen of which one half is white, the other dark brown. 3 Report on the Natural History of the Pearl Oyster of Ceylon, 1858-59. 16 fishery, corroborated all I have stated about the ovaria or genital glands and their contents, and that he has discovered, in addition to the filaria and cercaria, 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 pearls in other beds with these worms, and thus increase the quantity of these gems. The nucleus of an American pearl drawn by Mobius is nearly of the same form as the cercaria found in the pearl oysters of Ceylon.” The “ cercaria ” referred to were, probably, Cestode worms (Anthocephalus, &c.), which are found in the internal organs of various fishes caught off the coast of Southern India, and gave rise to a scare in the European fish-loving community afew years ago. During the recent fishery in only a few out of many hundreds of oysters which I examined did I find small nemertine worms living on the mantle or gills of the oyster, so that their presence cannot be regarded as a common or essential occurrence. The Gulf of Manaar pearl oyster (Avicula fueata, Gould) is represented in plate 1, as it appears after removal of one valve of its shell, the “ ovarium,” mantle, gills, adductor muscle, and byssus being exposed. The presence of a small pearl imbedded within the substance and projecting from the surface of the “ ovarium ” is indicated at A. The byssus (B), of which the function has given rise to much discussion and speculation, is made up of a bundle of tough, green- coloured fibres, secreted by a gland in the foot, and is capable of being protruded beyond, or retracted within the shell. By its means the animal is enabled to anchor itself on the sea-bottom to a neighbouring oyster or other molluse shell, coral-block, melobesian nodule, or other convenient object ; and it is said that the animal can, even in the adult stage, voluntarily shift its position and migrate to a con- siderable distance. That the young oyster can, during its phase of existence as a minute, free-swimming organism wander about and eventually settle down on some congenial spot no one will dispute; but the evidence that the adult oyster can, under natural conditions, migrate to any con- siderable distance is wholly insufficient, even though it has been demonstrated by experiments that a young pearl oyster under unnatural conditions in a soda-water tumbler full of sea-water can, though weighted with two other oysters of nearly its own size, climb up a smooth perpendicular surface Plate I Avicuta Fucata Peart Oyster ae ‘adler i ce ae bh 1h nam AES ' . ps es ; ath Gian)! | bw inannas A * it y F 5 ¥) a , x . ae Ae NE i i y, 13 } “ i Ao 4, eps Leis oh Arend Bis rr a i ‘4, | q oD ‘ My y i At p r ‘ Po he pe is At Ste ae Hy yr ey reas y i VA ‘7 s c ¥ ; r A Py an ry ‘ ‘ a i ; d is ' ; : Zs ‘ ae | Pay ay F pe Rays 8d ‘tly Ay de ia nN hit Te Al \ f hey os] ih, Bhs Ny nt ay coeur: Sill e ver) MOOR LE aieee tM Saad i 1S Wy ip Wey 1 "9 m 17 at the rate of an inch in two minutes. The mysterious disappearance of the oysters from the Ceylon pearl bank prior to a recent fishery must, I think, be attributed to the action of a strong under-current, and not to voluntary migration of the headless mollusc. The recent Tuticorin pearl fishery was carried on from a temporary improvised village, erected on the barren sandy shore at Salapatturai, 2 miles north of the town, and built out of palmyra and bamboo, the inflammability of which was demonstrated on more than one occasion. The village consisted of the divers’ and merchants’ quarters and bazars, where, as the fishing progressed, the product of the oysters was exposed for sale; bungalows for the officials connected with the fishery; a tent used by myself as a zoological laboratory ; dispensary; kottus (or koddus),: 7.e., enclosed spaces in which the counting, decomposition, and washing of the oysters are carried on; a Roman Catholic chapel ; and the inevitable isolated cholera quarters. The fishery commenced on the 25th of February under a combination of adverse conditions which seriously affected the revenue, viz., the presence of the pearl bank at a distance of 10 miles from the shore and in 10 fathoms of water, and the co-existence of a fishery on the Ceylon coast, where the oysters were to be obtained at a distance of about 5 miles from shore and at a depth of 5 to 7 fathoms. The natural result was that the natives, keenly alive to their own interests, went off with their boats from the Madras seaport towns of P&émban and Kilakarai to the Ceylon fishery, where they could earn their money more easily and with less discomfort than at Tuticorin, leaving the Tuticorin bank to be fished by a meagre fleet of about 40 boats. An excellent account of the method of conducting the pearl dishery at Tuticorin has been published in the ‘“‘ Hand- Book of Directions to the Ports in the Presidency of Madras. and Ceylon,” 1878, from which the following varies only in points of detail. The landwind, under favourable conditions, commences to blow soon after midnight, and a signal gun is fired by the beach master as a warning that the fleet of native boats, each with its complement of native divers, can start out to sea, their departure being accompanied by a good deal of noise and excitement. The bank should be reached by day- © 18 light, and the day’s work commences on a signal being given from a schooner, which is moored on the bank throughout the fishery. An attempt is made to keep the boats together within an area marked out by buoys, so as to prevent the bank from being fished over in an irregular manner, and the temper of the European officer in charge of the schooner is sorely tried by the refusal of the boatmen to comply with the conditions. All being ready on board, a diving stone, weighing about 30 lbs., to which a rope is attached, and a basket or net fastened in a similar manner are placed over the ship’s side. The ropes are grasped by the diver in his left hand, and, placing a foot on the stone, he draws a deep breath, and closes his nostrils with his right hand, or with a metal nose clip which he wears suspended round his neck by a string. Ata given signal, the ropes are let go, and the diver soon reaches the bottom, his arrival there being indi- cated by the slackening of the rope. He then gets off the diving stone, which is drawn up to the surface, and, after filling the basket or net with oysters, if he is on a fertile spot, gives the rope a jerk, and comes up to the surface to regain his breath. The contents of the basket or net are emptied into the boat, and the live oysters separated from the dead shells, débris, &c. The divers work in pairs, two to each stone, and the oysters which they bring up are kept separate from those of the other divers. A good diver will remain below the surface about 50 seconds, and, exceptionally, 60, 70 or even 90 seconds. The largest number of oysters collected as the result of a single day’s fishing by 41 boats during my visit to the fishery was 241,000, giving an average of 5,878 oysters per boat, a very small quantity when compared with the results of the Ceylon fishery in 1857, when the daily yield varied from one to one and a half million oysters, some boats bringing loads of thirty to forty thousand. From experiments made with divers equipped with diving helmets, gathering stones instead of oysters, by the late Superintendent of the Madras Harbour Works, it was calcu- culated! that a pair of helmeted divers could together send 1Vide Madras Board of Revenue Resolution, No. 677, dated 3rd August 88. 19 up 12,000 shells an hour in shallow water, or, allowing for delay in hauling up in 12 fathoms of water, say, 9,000 shells an hour; and as, allowing for shifts, each diver should work four hours a day, the quantity sent up by a pair of divers in a day would be respectively 4 x 12,000 = 48,000, or 4 x 9,000 = 36,000 shells a day, which is equivalent to the work of 24 or 18 naked native divers sending up 2,000 a day. The results of the work done by the two helmeted divers : who were employed as an experiment at the Tuticorin fishery fell far short of this calculation, and compared unfavourably with the work done by the skilled native divers without helmets. The diving operations cease for the day some time after noon, and the boats, if aided by a favourable sea breeze, reach the shore by 4 p.m., their arrival being awaited by large crowds of natives, some of whom come from curiosity, others to speculate on a small scale. On reaching the shore the boats are quickly made fast in the sand, and the oysters carried on the heads of the divers into the kottu, where they are divided into separate heaps, each set of divers dividing their day’s produce into three equal portions. One of these, selected by the Superintendent of the Fishery or some other official, becomes the property of the divers, who quickly remove their share from the kottu, and, squatting on the sand, put their oysters up for sale at prices varying from about 15 to 40 for a rupee. On the first day of the fishery the oysters, for a short and to the divers lucrative time, were sold for four annas a piece. The two heaps which are left by the divers in the kottu become the property of Government, and are counted by coolies engaged for the purpose. Usually about 6 p.m. the Government oysters are sold by public auction, duly announced by tom-tom, being put up in lots of 1,000; and the purchaser can, subject to the consent of the auctioneer, take a certain number of thousands at the same rate as his winning bid. Occasionally a combi- nation is organised among the merchants who are buying on a large scale, and come to the auction determined not to bid more than a very small fixed sum per 1,000. A struggle then takes place between the auctioneer and merchants, the former refusing to sell, the latter refusing to raise their price ; and the struggle invariably ends in the collapse of the merchants when they find that their supply of oysters is cut 20 off. No credit is allowed, and the buyers, as soon as they have paid their money into the treasury, remove their oysters to the washing kottus, or send them away up-country by railway. Buyers of oysters on a very small scale open them at once with a knife, and extract the pearls by searching about in the flesh of the animal ; but, by this method, a number of the very small pearls are missed, and it would be impossible to carry it out when dealing with oysters in large numbers. Boiling the oysters in water and subsequent extraction of the pearls from the dried residue might be, with advantage, resorted to as a more wholesome and less unsavoury process than the one which is commonly resorted to of leaving the oysters to putrify in the sun, and subsequently extracting the pearls from the residue after it has been submitted to repeated washings to free it from the prevailing maggots, pulpy animal matter, sand, &c. The process of putrefaction 1s greatly aided by flies—big red-eyed blue-bottles. At the Ceylon pearl fishery, which I was sent to inspect on the termination of my work at Tuticorin, the merchants com- plained at first of the scarcity of flies; but, later on, there was no cause for complaint, for they were present not only in the kottus, but in other parts of the camp, in such enormous numbers as to form a veritable plague, covering our clothes with a thick black mass, and rendering the taking of food and drink a difficult and unpleasant process until the even- ing, when they went to rest after twelve hours of unceasing activity. For months after the conclusion of a pearl fishery poor natives may be seen hunting in the sand on the site of the pearl camp for pearls, and it is reported that in 1797 a common fellow, of the lowest class, thus got by accident the most valuable pearl seen that season, and sold it for a large sum. Towards the latter end of 1888 it was suggested that an electric light apparatus should be acquired in connection with the pearl fishery, by means of which one would be able to examine the condition of the bank from the deck of a ship, and which, it was thought, would help to solve the enigmas that still hang about the migrations of the pearl oyster. The notice of Government was drawn to the fact 21 that a boat had been fitted up with a brush-dynamo and electric globe for the pearl fishery in South Australia by a Glasgow firm. During a recent visit to Europe, I made a series of inquiries as to the possibility of obtaining a light, such as was required; but, though there was abundant evidence as to the use of the electric light for surface work, salvage operations, and scientific dredging,' the general opinion of those best qualified to judge was that it would, for the proposed purpose, be a failure. It has been sug- gested by Mr. G. W. Phipps, who was for many years Superintendent of the Tuticorin pearl banks, that, if a sheet of thick glass could be let into the lower plates of a vessel and there protected both outside and inside in some way from accident, a study of the sea-bottom in clear water, either by day with the sun’s rays or by night by the use of a powerful electric light, might be made. In a letter to Government Mr. C. E. Fryer, Inspector of Fisheries, makes the sound suggestion “ that the observations which the Gov- ernment of Madras desire to make upon the habits of the pearl oysters would be greatly facilitated by the employment of a diver equipped with an ordinary diving dress. By this means a prolonged stay could be made by an observer on the sea-bottom, who could not only make an accurate survey of the bed, but could periodically examine the same ground, select specimens, and make minute observations, which would be impossible to a native diver, whose stay at the bottom is limited to a minute or so.” To these remarks I may add my own experience at the Tuticorin fishery, where, by examination of the shells of the oysters brought up by the divers, by expending small sums of money which tempted the native divers to bring me such marine animals as they met with at the sea-bottom, by conversation with the European diver, who was, further, able to bring up large coral blocks (Porites, Madrepora, Hydnophora, Pocillopora, Turbinaria, &c.) for examination, and by dredging, I was able toe form some idea as to the conditions under which the pearl oysters were living. On clear days it was possible to distinguish the sandy from the rocky patches by the effect of light and shade, and from hauls of the dredge over the former not only many mollusca, &c., but also specimens 1 Vide Herdman’s 2nd Annual Report on the Puffin Island Biological Station. 22 of Branchiostoma, sp.! (Lancelet) were obtained, of which the largest measured two inches in length. Mollusca were also obtained in great variety by passing the débris, which was swept from the floor of the kottoo every day after the oysters had been cleared away, through sieves. ‘The big Murex: anguliferus (Elephant Chank) was brought in from the banks by the divers nearly every day, and the animal served up for their hard-earned evening meal. The oysters shells were largely encrusted with bright-coloured sponges, of which the most conspicuous was Clathria indica (n. sp.) an erect-growing bright red species, recorded by Mr. Dendy in his report on my second collection of sponges from the Gulf of Manaar.2 Very abundant, too, was the large cup- shaped Petrosia testudinaria, of which a specimen in the Madras Museum measures 1°5 feet in height. Enveloping the oyster shells were tangled masses of marine Algae,’ and floating in dense masses on the surface was the Sargasso weed, Sargassum vulgare. The various minute living organ- isms entangled in the meshes of the Alga must serve as an efficient food-supply for the oysters. The outer surface of the living oyster shells was frequently covered with delicate Polyzoa, which also flourished on the internal surface of the dead shells in the form of flat or arborescent colonies. In no single instance did I see an oyster shell from the Tuticorin bank encrusted with coral; whereas at the Ceylon fishery, on the sole occasion on which I had an opportunity of examining the oysters brought in from the pearl bank, I found the surface of a large number of the shells, both dead and living, covered, and frequently entirely hidden from view by delicate branching Madrepora or Pocillopora, or the more massive Astrea, Celoria, Hydnophora, Galavea, &. A specimen of G'alavea encrusting a single valve of an oyster shell, which I picked up on the shore and is now in the Madras Museum, weighed as much as 5 oz. 15 dwts. Several species of Hehinoderm, which have not hitherto been recorded from the coast of the Madras Presidency,* 1 Specimens of Amphiorus belcheri, Gray, were obtained by Mr. Giles, when dredging from the Marine Survey SS. ‘‘ Investigator” off Seven Pagodas (Mah4balipuram) 30 miles south of Madras during the season 1887-88. 2 Ann. Mag., Nat. Hist., Feb. 1889. 8 The collection of Algwe made at Tuticorin has been sent to the British Museum (Nat. History) for identification. 4 Vide Proc., Zool. Soc., Lond., June 19, 1888, 23 were brought up by the divers, and have been sent to my friend Protessor Jeffrey Bell for identification. Of recorded species those which were brought on shore most frequently were the crimson-lake coloured Oreaster lincki, and the long- armed, usually salmon-coloured Linckia levigata, and, not unfrequently, dense clusters of Antedon palmata were found in crevices hollowed out in coral blocks, from which also, when broken open, specimens of Ophiuroids (commonly met with their arms turned round the branches of a Gorgonia, or in the canal system of sponges), Annelids, Crustaceans, and stone-boring Mollusca (Lithodomus, Parapholas, Vene- rupis, &c.) were obtained. bl - ‘aa - Il.—NOTE ON PEARLS FROM MYTILUS AND PLACUNA. J - 4 ¥ "* — y ‘ 4 4 ¥ . . 4 ad . ts ° A ' : - - A = ae - a; a 7 ‘ r ‘ . “an ' . . 7 . . . i 4 . ‘ ’ i > wp. te meetin te oe veeteniterp lien al kag ie ld mene Se II.—NOTE ON PEARLS FROM MYTILUS AND PLACUNA. In addition to the pearl oyster of the Gulf of Mannar, two other pearl-producing mollusca (Mytilus smaragdinus and Placuna placenta) are to be found in the Madras Presidency : the former in the Sonnapore river in the Ganjam district, where they are, or were till recently, the source of a local industry ; the latter on salt mud flats and in canals in various parts of the presidency, e.g., Pulicat Lake, the Buckingham Canal, Tuticorin, &c. As regards the former (If. smaragdinus), samples of the pearls were sent to Government by Mr. R. Davison, when Acting Collector of Ganjam in 1875, and examined by pearl merchants, who reported that they were of very inferior quality and of the description termed “ rejected pearls ” by the trade, and valued a big discoloured pearl at Rs. 1-8-0 and the whole sample at Rs. 7. The following extract is taken from a letter to Government by Mr. Davison, who, as the result of a visit to the mussel beds, which was resented by the natives who were interested in keeping the habitat of the mussels secret, suggested that, if taken in hand and properly treated, the pearls might eventually become a fruit- ful source of revenue :— ‘‘Sonnapore is a small fishing village situated near the mouth of a river to which it gives its name, and which is about 12 miles south of Gopaulpore. For some miles up the river there are large beds of the ordinary edible oysters, which find a ready market at Berhampore and elsewhere. Mixed up with the ordinary oysters, and adhering most tenaciously to their beds, are the bright green mussels, from which the pearls are produced. ‘‘T had five canoes, with four divers in each, at work, and the place where we were most successful is situated about two miles from the mouth of the river and about half a mile beyond the custom house. Each diver brought with him a long bam- boo pole, which he drove with all his might into the oyster bed at a depth of from ten to twelve feet of water according to tho state of the tide. He then dived to the bottom, and holding ° DMA 28 on to, or keeping near the bamboo, broke off as large a mass of oysters as he could conveniently bring to the surface in one hand, and with the other he helped himself up the bamboo. Any mussels that were found adhering to the block of oysters were secured, and the oysters were returned to the water, as thousands of them have already, from time to time, been ex- amined in vain. I was amazed at the dexterity and rapidity with which the divers opened the mussels with knives made for the purpose ; and the expert manner in which they ran their thumbs over the molluscs, detecting in an instant without fail the most minute seed pearl not larger than a pin’s head, leaves no room for doubting that long practice has made them perfect in this particular branch of what has hitherto been to them a highly lucrative employment.”’ The flat, transparent shells of Placuna placenta (window shell) are used in China and at the Indo-Portuguese Settle- ment Goa as a substitute for window glass; and the small pearls which the animal produces are exported to India to be calcined into chuném, which rich natives chew with their well-beloved betel, and are said to be burned in the mouths of the dead.!. So far as I am aware the pearls which might be obtained from the masses of Placuna which live in the mud flats of Southern India have not been utilised as an article of commerce. But an extensive Placuna pearl fishery has been carried on at Tamblegam lake in Ceylon; and some idea of the abundance of the mollusc may be gathered from the fact that the quantity of shells taken in the three years prior to 1858 could not have been less than eighteen millions. 1 Vide Tennent’s Ceylon, II, 492. II].—THE TUTICORIN CHANK FISHERY. oe ‘ a d y 1 i! “1 I , P f ; f : fi \ iy hl j " Z ve vie f ‘ by eae . { a . ; i , nae aes 54 gay ase ? ' : oe Ih ok ee th ae a Martie ink oo . ee a fi 4h) et a Jans ty Mn Meprocy tee sash eames) aye Roa 1 as apt nye 7 . ' i. : iy y » i oy 7 { te Do aah H A } p 7 ; * - t as id Wie i YH ie is ry ; > SSS SSN Plate It TURBINELLA RAPA THE CHANK III.—THE TUTICORIN CHANK FISHERY. Tue sacred chank or sankh is the shell of the gastropod molluse Turbinella rapa, of which a full-grown specimen is represented on plate II, and is, like the pearl oyster and the edible trepang (Holothuria marmorata) a commercial product of the Gulf of Manaar. The chank which one sees suspended on the forehead and round the necks of bullocks in Madras is not only used by Hindus for offering libations and as a musical instru- ment in temples, but is also cut into armlets, bracelets, and other ornaments, and writing in the sixteenth century Garcia says ! :— ‘*« And this chanco is a ware for the Bengal trade, and formerly produced more profit than now...... and there was formerly a custom in Bengal that no virgin in honour and esteem could be corrupted unless it were by placing bracelets of chanco on her arms; but since the Patans came in, this usage has more or less ceased, and so the chanco is rated lower now.” The chank appears as a symbol on some of the coins of the Chalukyan and Pdéndyan empires, and on the modern coins of the Rajas of Travancore. The chank fishery is conducted from Tuticorin, and the shells are found in the vicinity of the pearl banks, in about 7 to 10 fathoms,” either buried in the sand, lying on the sea bottom, or in sandy crevices between blocks of coral rock. The fishery goes on during the north-east monsoon from October to May, and is worked by native divers, who, put- ting their foot on a stone to which a long rope is attached, are let down to the bottom, carrying a net round the waist, in which they place the chanks as they collect them. The shells of the chank are scattered about, and not aggregated together in clusters like those of the pearl oyster, so that the 1 Vide Yule and Burnell Hodson Jobson, 1886. ?For a discussion of the chank as an enemy of the pearl oyster, vide Mr. H. S. Thomas’ Report on Pearl Fisheries and Chank Fisheries, 1884. cet 32 divers have to move about on the bottom from place to place in search of them. The divers usually stay beneath the surface from 40 to 50 seconds. The longest dive which I have myself witnessed was 54 seconds, and on that occasion the diver, on his return to the surface, innocently inquired how many minutes he had been under water. Pd FAMILY GYMNODONTES. Tetrodon hispidus. Pamban. ak margaritatus. Pamban. ‘5 immaculatus. Pamban. Diodon hystrix. Pamban. », maculatus. Pamban. See Day’s Suppt., p. 809. 95 Leptocephalus, sp. (Pl. iv.) As regards the curious pellucid Leptocephali, of which I have obtained a few specimens in the Gulf of Manaar, and a large number from the meshes of the fishermen’s nets at Gopalpur, where they are known as sea-leeches, Dr. Giin- ther says :! ‘‘We must come to the conclusion that these leptocepha- tids are the offsprings of various kinds of marine fishes, repre- senting, not a normal stage of development (larve), but an arrest of development at a very early period of their life ; they continue to grow to a certain size without corresponding development of their internal organs, and perish without having obtained the characters of the perfect animal.” 1 Introduction to Study of Fishes, 1880, pp. 179-182. ~ *\ . t . iP) ; ‘ a . , ' mtg ey aftr ra . fay ee vt sal eat Tite f Hoe Sie taf co e yA D > sa “ag ’ rr. vo oe ‘ hes ofh 5 ; j 4 - » ai Pz TL Ge wet. « i, ).: "F 4 ‘ } > q % id , 2 ~ a3 : ~ - 7 f , ‘ ry % ‘ +. e i] 4 7. . as ee Ha i ‘ { ' ’ \ r , . . ¢ . . " ~ F. : > ‘ - ’ | . an * 8 1 . . - . ‘ * \ . « ‘ i he ™“ ° * ‘a > ix a ; P F ‘ id 3 e —_ A FS : Me 4 2tn wr ' aoe © . & Py = - ‘ Py vt, ee ¥. Mi eae 7 VIL—INSPECTION OF CEYLON PEARL BANKS. VII.—INSPECTION OF CEYLON PEARL BANKS. Havine received permission from His Excellency Sir Arthur Gordon, k.c.M.c., to accompany Captain Donnan, the In- spector of the Veylon Pearl Banks, on his annual inspection cruise, I left Madras for Colombo by 8.8. Aewa on the ord October 1889, taking with me some young plants of Victoria regia, reared in the nursery of the Madras Agri- Horticultural Society, for planting in the new Fort Gardens at Colombo. Some seeds of the Victoria, which had been sent from Madras earlier in the year, had germinated a short time before my arrival, and the young plants looked thoroughly healthy, so that it is to be hoped that the intro- duction of the water-lily will be successful. While in Colombo I took the opportunity of examining the excellently preserved specimen of Rhinodon typicus in the Ceylon Government Museum for the suke of comparison with the specimen, more than 20 feet in length from the end of the snout to the extremity of the tail, which was cast on shore at Madras in February 1889, when I was unfortunately far away from head-quarters, so that the chance was missed of examining its stomach contents and internal anatomy. As the following extract shows, but few specimens of this monster Hlasmobranch have been recorded ! :— ‘‘ For many years the sole evidence of its existence rested upon a stray specimen, 15 feet in length, which was brought ashore in Table Bay during the month of April 1828, and for- tunately fell into the hands of the late Sir Andrew Smith, then resident in Capetown, who named, described, and figured it. The specimen itself was preserved by a French taxidermist, who sold it to the Paris Museum, where it still remains in a much deteriorated condition. Forty years later, in 1868, Dr. Percival Wright, whilst staying at Mahé with Mr. Swinburne Ward, then Civil Commissiouer of the Seychelles, met with this shark, and 1 In his “‘ Account of the Pearl Fisheries of Ceylon’? Captain Steuart records having seen on one occasion ‘‘a spotted shark of a most fearful size ; it was accompanied by seyeral common sized sharks, and they appeared like pilot fish by its side.” S , 100 obtained the first authentic information about it. It does not seen to be rare in this Archipelago, but is very seldom obtained on acount of its large size and the difficulties attending its capture. Dr. Wright saw specimens which exceeded 50 feet in length, and one that was actually measured by Mr. Ward proved to be more than 45 feet long. Nothing more was heard of the creature until January 1878, in which year the capture of another specimen was reported from the Peruvian coast near Callao; finally, in the present century, Mr. Haly, the accomplished Director of the Colombo Museum, discovered it on the West Coast of Ceylon, and succeeded in obtaining two or three specimens. One of these was presented by that institu- tion to the Trustees of the British Museum, and, having been mounted by Mr. Gerrard, it is now exhibited in the Fish Gallery, where it forms one of the most striking objects, although it must be considered a young example, measuring only 17 feet from the end of the snout to the extremity of the tail. “A true shark in every respect, Rhinodon is distinguished from the other members of the tribe by the peculiar shape of the head, which is of large size and great breadth, the mouth being quite in front of the snout, and not at the lower side, as in other sharks. Each jaw is armed with a band of teeth arranged in regular transverse rows, and so minute that, in the present specimen, their number has been calculated to be about 6.000. The gill openings are very wide ; and three raised folds of the skin run along each side of the body. Also in its varie- gated coloration this fish differs from the majority of sharks, being prettily ornamented all over with spots and stripes of a buff tint.”’ After waiting for several days on the chance of a moder- ation of the prevailing south-west wind, I left Colombo with Captain Donnan on the barque Sw/tdn Iskander, which towed after her the diving boats, each with its crew composed of coxswain, rowers, divers, and munducks who attend to the divers, letting them down by ropes, pulling them up, &e. The steam-tug Active followed us on the following day. As an inspection of the reported pearl bank off Negombo was out of the question owing to the heavy swell, we sailed straight on to Dutch Bay, where we anchored, after a some- what boisterous journey, on the following morning, inside the long and rapidly extending spit of sand, which forms the western boundary of the bay, on which the sale bungalow, kottus, &e., were standing during my last visit in March at the time of the collapse of the pearl fishery. The Bay now presented a very deserted appearance, a few fishermen, living in huts and earning a modest living by curing sharks and bony fishes, and a number of natives, from near and dis- 101 tant parts of the island, engaged in searching for stray pearls in the sand formerly oceupied by the washing kottus, the site of which was indicated by the remains of the fences and heaped up piles of oyster shells, and gaining as the reward of their labour from one to two rupees a day, being the sole human occupants of the sandy shore, on which hosts of wading birds were congregated. It was reported that one woman had found five pearls, each of the size of an ordinary pepper seed, for which she had been offered and refused 150 rupees. The seaward face of the sand-spit was strewed with coral fragments rolled in by the waves from the reef, which inter- venes between the shore and the pearl bank, and is partially laid bare at low tide; and the sand was riddled with the burrows of a very large Ocypod (O. platytarsis). If one of these crabs is killed and left on the shore, its fellow creatures carry it away into a burrow, and, doubtless, devour it. On the day after our arrival at Dutch Bay we sailed in one of the diving boats to Karaitivu and Ipantivu islands and the mainland in search of a possible spot adapted for the requiremeats of a pearl camp at the next fishery. In the shallow water near the shore of Karaitivu island fishes— Mugil and Hemiramphus—-some of which leaped into the boat and were eventually cooked, fell easy victims to fishing eagles and gulls. Two hauls of the dredge in the sand and mud brought up Amphiorus, Lituaria phalloides, the Trepang Holothuria marmorata, Astropecten hemprichit, Philyra scabri- uscula, Chloeia flava, and many molluses ; the majority of the species of mollusc, both here and in Dutch Bay, being common to the Indian and Ceylon Coasts of the Gulf of Manaar. On the mainland forming the eastern boundary of Dutch Bay, into which the river Kala Oya discharges its water by several mouths, dense jungle and swampy ground teeming with the molluse Pyrazus palustris reach right down to the water’s edge; and, as we walked along the shore, we came across solid evidence of the recent presence of elephants. We were told by a native that bears and wild pigs are so thick in the jungle that one trips over them as one walks along ! In 1868 large numbers of young pearl-oysters are re- ported to have been spread over a considerable extent of the muddy bottom of Dutch Bay in from one to two fathoms 102 of water, but the situation was, evidently, not favourable for their healthy growth.! The weather being unfavourable for the work of inspect- ing, we had to remain unwillingly in Dutch Bay, the days being spent in cruising about, and dredging in the shallow water. But on the 2¥th, as the wind had changed and the sea abated, we made a start for the neighbouring pearl bank—Muttuwartu Par—to which we were towed by the Active. As soon as we had anchored on the south end of the bank a diver was sent down from the ship’s side in 6¢ fathoms, and brought up his rope basket containing plenty of healthy, living oysters, which, he reported, came away easily from the “ rock” to which they were attached by their byssi.2 At the fishery in March the divers complained of the difficulty in detaching the oysters; and the ease with which they can be gathered is considered a sign whether they are ripe for fishing or not, the byssus being said to begin to break away from the substance to which it adheres tightly in the early existence of the oyster after the 5th year. The excellent system which is employed in the inspection of the Ceylon banks, and by which a thorough knowledge of the condition of the banks is obtained, is as follows. The inspection barque is ancltored in a position fixed on the chart by bearings from the shore. The steam tug, towing a boat with buoys bearing flags on board, first lays out buoys in the north, south, east, and west at distances of }, 3, and $ of a mile from the barque. Buoys are then laid out at a distance of ? of a mile from the bargue in the north- east, north-west, south-east, and south-west. Four diving boats, each with a coxswain in charge, 5 rowers, 3 divers, and 2 munducks, are arranged in line between the north 4+ mile buoy and the barque, the distance being equally divided between the boats. The rowers work round in a circle, and the divers make frequent dives in search of oysters until the starting point is reached. The boats are then again arranged in position, and the circle between the } and $ mile buoys is explored. Lastly, the third circle, between the $ and $ mile buoys, is, in like manner, explored; so that, when 1K. W. H. Holdsworth. Report on the Conditions and Prospects of the Pearl-Oyster Banks, 1868. 2 «© The term rock is applied to pieces of coral, living or dead, averaging about a foot in diameter, which are scattered more or less thickly over certain parts of the banks.’’ Holdsworth, /.c. AD irene eal amine ao ; - 5 ed, . 5% _Aemms TR ee “+ * ee eu =." oe oe Sigh * c i” ke DIAGRAM. A Lithographed in Central Survey Office, Madras 1890 DIAGRAM. B ‘Lithographed in Central Survey Office, Madrag 1886 K ‘ ee ee ee eS a EE eee oJ ‘ me - ‘ 4 ‘ “ . ¢ kp : pe atti ; a ce 9 be *-. ; , + em | ' , to is = ay. r P e , 7 ¢ . *, ib A £ ia) . anole aoihO save lana it ipAk AY ne - ub ‘ - nie 4 RP Alp f : an Be agit 2 ae Lar , irennene NO ro adel 103 this circle is completed, each boat has described three circles with the inspection barque as a centre. And, in this way, twelve circles in all are described by the four boats, ‘The oysters are then brought to the ship, counted, and put in sacks daily, until a sufficient number (15,000) to form a sample for washing and valuation by experts has been col- lected! The coxswain of each boat records on a diagram, provided by the Inspector, the approximate position of each dive which is made, the nature of the bottom (a triangle = rock, a circle = sand, and a cross oysters), and the number of oysters lifted. Diagram A represents the day’s work done by one boat over ground which, with the exception of a sandy patch between the vorth and east # mile buoys, was rocky, and on which oysters were plentiful except over a portion of the outer circle. Diagram B, made up from the four coxswains’ reports, represents a single day’s work done by all the boats, and shows the distribution of the oysters over the area inspected, and the limits of the bank. As soon as the buoys have been taken up by the tug the inspec- tion barque is moved to a new position ]4 mile distant from its former one, and the buoys are again laid out in circles, to act as guides to the boats in the next day’s work. Without the assistance of the buoys the boats would not be able to describe separate circles, but would work in an irregular manner, and two or more boats would, very probably, go over the same ground. But, with the assistance of the buoys, the whole bank can be systematically surveyed. ~The Muttuwartu Par, which was fished in the spring of 1889, is situated about 5 miles from the seaward shore of Dutch Bay, and covers an approximate area of 3 x 13 miles, the depth of water over the bank ranging from 5 to 10 fathoms with an average of about 7 fathoms. The temperature of the water at the bottom, registered with a Negretti and Zambra’s deep-sea thermometer, varied from 80° to 82° between 8 a.m. and 5 p.m. The specific gravity of the surface water, tested with a Twaddell’s hydrometer regulated for a temperature of 84°, was, approximately, 1:025. Between the bank and the shore is a coral reef, the presence of which was indicated by the waves breaking over its outer face amid a prevailing calm, and by gulls resting on the coral blocks. The most conspicuous Madreporaria _ | If a young bank is being inspected, samples are brought up by the divers, but they are not washed for valuation. 104 on this reef, which is surrounded by 4} to 5 fathoms of water, belong to the genera Madrepora and Pocillopora, while Galaxea and Leptoria are present in less abundance. The bright white patches of sand, which cover large spaces between the coral growths, teem with Protozoa and a calcareous A/ga, and are more rich in delicate molluses than any other deposit which I have examined in the Gulf of Manaar. Sheltered among the coral tufts were sluggish Holothurians and hosts of small Crustaceans; and, clinging to the branches of a Madrepore, I found a single specimen of the quaint Thenus orientalis. Outside the seaward face of the pearl banks on the Indian coast of the Gulf of Manaar the depth of the sea increases very gradually, so that, for example, outside the Tholayiram Par, a depth of only 15 to 20 fathoms is reached at a distance of 3 miles. Outside the Muttuwartu Par, how- ever, the area of shallow water ceases very abruptly, and the depth increases rapidly to 150 fathoms at a distance of three- quarters of a mile from the seaward face of the bank, where the following temperatures were recorded :— Surface ti Re 60 fathoms .. 68° 10 fathoms an Bl? 100 nee cjein, Hoa Dy ee Oe oar esa = cy aioe Ae ie i Several hauls of the dredge brought up Polytrema cylindricum, Gorgonie, Heteropsammia cochlea, Cirrhipathes spiralis, Spongodes sp., Fibularia orulum, &c., but no pearl- oysters. The divers received instructions to keep apart for me everything, other than oysters, which they came across during their day’s work, under the general heading of corals, shells, poochees, and weeds; and, by examination of the specimens which they reserved and going rapidly over the oysters, I was enabled not only to make a rich collection which awaits future investigation, but also to. ascertain roughly in what respects the fauna of this portion of the West Coast of Ceylon differs from that of the Indian Coast of the Gulf of Manaar. The first day’s inspection of the Muttuwartu Par showed not only that the oysters were very abundant, in spite of the disturbance to which they were subjected during the fishery in the spring, 4,580 living specimens being brought up in 291 dives; but, further, that the coral-incrusted shells, to which I have already referred 105 (p. 38), as being a distinguishing characteristic of this bank as compared with the Tholayiram Par, are very abundant, and belong to the genera Madrepora, Montipora, Hydnophora, Porites, Pocillopora, Galaxea, Cyphastrea, Celoria, Favia, and Goniastrea ; the living corals growing on the shells of living oysters, which, did they migrate, would have, sometimes, to carry about with them a weight of nearly 8 ounces. The coral-incrusted shells had, prior to the fishery of the Muttuwartu Par this year, only been seen by Captain Donnan on the North-west Chéval Par; and, when the oysters disappeared from the latter in 1888, the drift-oysters, which were eventually found, were recognised by the coral-growths upon them. Arborescent sea-weeds, forming tangled masses, such as abound on the Tholayiram Par, were conspicuously absent; but the oyster shells were largely encrusted with incrusting sponges, and the orange-coloured Axinella donnani, which receives its specific name after the present Inspector of Pearl Banks, was very common. In addition to the shell-incrusting corals massive corals, mainly belonging to the genus Madrepora, flourish on the bank, forming a convenient habitat and hiding place for Annelids, Crustaceans, Molluscs, &c., which can live there safe from the attacks of predaceous enemies. The sea bottom is, so far as I could gather from repeated examination, on different parts of the bank, of the residue left after shaking up the oysters in a bucket of water, and of the contents of the digestive tract of a Holothurian (H. atra) which abounds on the bank, mainly composed of a white deposit, such as I have only seen on the Indian Coast of the Gulf of Manaar, which is composed of a calcareous Alga and Foraminifera, among which Rotalia _calear, Heterosteyina depressa, and A:mphistegina lessonii are the most conspicuous. It was long ago pointed out by Captain Steuart that the places, on which pearl fisheries have been successfully held in Ceylon, appear to be beds of Madrepore of irregular heights, having the spaces between the ridges nearly filled up with sand. ‘The transparent clearness of the water over the banks, and the clean state of the sea bottom, which is free from sediment carried down by currents, must, I think, be regarded as important conditions favouring the healthy growth of the oysters thereon. Swimming about on the surface of the water over the bank were many black and yellow striped sea-snakes, which are believed by the divers to feed on the oysters. Indeed, in 1862, the European diver reported that he had seen the (0) 106 snakes eating the oysters, darting into the shells when opened. But this report must be viewed with grave suspicion. Apart from snakes, the reputed enemies of the pearl-oyster on.the Ceylon banks are molluscs, fishes, and currents. Among molluscs are mentioned the Chank (Turbinella rapa) and a — big Murex (M. anguliferus), known as the Elephant chank. But, as Mr. Holdsworth observes, ‘‘ they may be looked on as part of the vermin of the banks, but I have no reason to think they cause more destruction on the oyster beds than the hawk and the polecat do among the game of an ordinary preserve.” It is noticeable that the little Modiola known as suran, which assumes such a prominent position in the reports of the Inspector of Pearl Banks at Tuticorin, does not, though present, occur, so far as 1 am aware, in any great quantities on the Ceylon banks. Among fishes the trigger fishes (Balistes), commonly known as “Old Wives”, are abundant on rocky parts of the banks, and I saw many specimens caught by the boatmen fishing from the side of the ship as we lay at anchor. Concerning these fishes Captain Steuart reports that ‘“‘the sea over the pearl banks is well stocked with various fishes, some of which feed on the oysters, and, when caught by the seamen on board the guard vessel, pearls and crushed shells are often found in their stomachs, particularly in the fish called by the Mala- bars, the Clartee ; by the Singhalese, the Pottooberre ; and by seamen, the Old Women. ‘This fish is of an oval-shape, about 12 inches in length and 6 inches in depth from the top of the back to the under part of the belly, and is covered with a thick skin. We saw ten pearls taken from the stomach of one of these fish on board the Wellington.” The contents of the stomach and intestines of Balistes, which I examined while we were inspecting the Chéval Par, consisted entirely of young oysters crushed by their sharp cutting teeth. In addition to the trigger fishes, Rays are said to be always more or less numerous on the banks, and 7 Mr. Holdsworth states that “when the fishery of 1863 i commenced on the south-east part of the Chéval Par, the divers reported the ground so covered with skates as to interfere with their picking up the oysters. After a day or two the continual disturbance by the divers had the effect of driving the skates away from that part of the bank, and these fish, many of them of very large-size, were seen going in the direction of the Modrigam, which was then covered with oysters, whose age was estimated by the Superin- tendent at 24—3 years, by the Inspector at 34—4, and 107 by the native headman at 4 years. The skates were in shoals, and their total number was estimated at from 10 to 15 thousand. Further, in his report on the inspection of banks in March 1885, Captain Donnan notes the fact that “on the way from the north Motaragam, and just about the south side of the bed of oysters, we passed through a large patch of thick discoloured water, caused by a shoal of Rays plundering about on the bottom, and stirring up the sand. Some of them could, at times, be seen near the surface, and I have no doubt they were feeding on the oysters.”” Some years ago the Sea Customs Officer at Dutch Bay counted as many as 300 Rays in a single haul of a fishing net. The native belief is that the Rays break up the oyster shell with their teeth, and suck out the soft animal matter. The stomach of a big Ray (Atobatis narinart), 5 feet in breadth and with a tail 84 feet in length, which was caught by fishermen from a canoe off Silavaturai - when we were at anchor there, consisted of sea weed. The same fishermen caught for me off the Sildvaturai reef a male Dugong, 9 feet in length, whose stomach contents consisted of sea weed and large numbers of a Nematoid worm. It was roughly estimated as the result of the inspection of the Muttuwartu Par, which lasted over three days, an average of 589 yards and 16 oysters to a dive being allowed, that it contained 30 million oysters spread over an area of 93 million square yards, which should produce a revenue of 5 lakhs of rupees. On November 2nd we left the Muttuwartu Par, and anchored in 8 fathoms, about 2 miles further north, so as to hunt for a possible bed of oysters. The divers, making the usual preliminary dives, brought up blocks of dead coral- rock with living Turbinarice and Porites growing on them, and containing, imbedded in the crevices, a large number of Foraminifera. The sample of 15,000 oysters from the Muttuwartu Par, which were beginning to be unpleasant ~ fellow-passengers, was sent up to Silévaturai to be washed. It is stated by Cap‘ain Steuart that the offensive effuvium of decomposing oysters “is not considered to have an unhealthy tendency on the persons engaged in the kottus, and it is astonishing how soon the most sensitive nose becomes accus- tomed to the smell. Indeed some Europeans have fancied their appetites sharpened by visiting the kottus, and being 108 surrounded by immense heaps consisting of millions of oysters in all stages of decomposition.” The surface of the water, always rich in organisms, was exceptionally so on the following morning, the tow-net, dropped from the stern of the barque and kept distended by the gentle current which ‘was running, becoming speedily filled with a gelatinous mass composed mainly of Sagittie mingled with a host of Ctenophora, glassy molluscs, and hungry fishes preying on Crustacean and other larve. Only a few young oysters being found, we again proceeded north- ~ ward, and anchored in 83 fathoms, the preliminary dives bringing up Madrepores with Antedons entwined round their branches, and large Melobesian nodules. Again only a few scattered oysters were obtained as the result of a day’s work, but the divers brought me many specimens of Alcyonians, and the bright-red sponge Aainella tubulata, living attached by a broad base to dead coral-rock, and associated with its commensal worm.! The following temperature observations | were made half a mile west of the ship, where no bottom was reached with the sounding line at 140 fathoms :— Surface 3 eno” 50. fathoms... Wao 20 fathoms .. 76°5° 100 e o'se4n eae ee ee 140 (ties 1. 55° On the afternoon of the 4th, we moved on, still north- ward, to the Karaitivu Par,? which was estimated, at the inspection in November 1887, to contain 1,605,465 oysters. The divers, going down from the ship, alighted on a bank of Fungie, and brought up some living 5-year old oysters and Melobesiun nodules. Attached to one of the nodules was an extensive creeping colony of the delicate crimson-coloured organism named Tubipora reptans from the single small specimen which has hitherto been recorded by Mr. H. J. Carter.2 The present specimens were in a more advanced stage of growth than the one described by Mr. Carter, which I examined in the Liverpool Museum last year, and the calycles were proportionately higher. By about four hours’ work next morning a sample of 8,000 oysters was collected 1 Vide Ann. Mag. Nat. Hist., Feb. 1889, p. 89. 2 The Karaitivu Par was fished in December 1889; but the fishery came to an abrupt termination owing to a diver being killed by a shark. Apparently three men went down into the water, and two came up almost directly, saying that the third had been carried off by a shark. The rest of the divers could not be prevailed on to resume work, and left the bank. 3 Ann. Mag. Nat. Hist., June 1880, p. 442. 109 for valuation, and the abundance of oysters may be judged from the fact that, on more than one occasion, as many as 100 oysters were brought up at a single dive. My own share of the morning’s work consisted of a Fungia (F. repanda) and three living specimens of the pearl-oyster Avicula (Meleagrina) margaritifera, attached by its byssus to coral-rock. Captain Donnan informs me that he has only seen about a dozen specimens of this molluse during his 28 years’ experience as Inspector of the banks, so that it cannot be present in any abundance. Shell-incrusting corals, though present on the bank, were far less common than on the Muttuwartu Par. : On the afternoon of the 5th we sailed about 20 miles north, and anchored in 2 fathoms, 3 miles south of the village off Aripu, off Sila4vaturai, which is made the head- quarters at times when the Chéval and Motaragam (Mud- rigam) banks are fished. Rising from the sandy shore between Aripu and Sild4vaturai is a miniature sand-cliff, reaching a maximum height of about 12 feet, and extend- ing over a distance of about half a mile, which contains a thick bed composed almost entirely of pearl-oyster shells— evidence of the enormous number cf oysters which have been taken from the neighbouring banks at fisheries in the past. Similar beds of oyster shells were exposed in sections nearly a mile inland. ‘The Chéval and Motaragam banks are situated from 9 to 12 miles out at sea in water varying in ‘depth from 6 to 10 fathoms. Between the shore and the banks the water gradually reaches a depth of 6 fathoms; but, as in the case of the Muttuwartu and Karaitivu Pars, the depth increases rapidly to 150 fathoms outside the banks. The sea bottom hetween the shore and the banks is made up mainly of sand with many worn shells, a luxuriant growth of sea-weeds, and scattered coral patches. Among mollusca Dodiola tulipa in an advanced stage of growth, and the chank ( Turbinella rapa) were very abundant. No fishing for chanks is permitted south of the Island of Manaar, lest, at the same time, raids should be made on the pearl banks. The fishery is, however, actively carried on north of the island on a dif- ferent system to that which is in force at Tuticorin (p. 33), the boat-owners paying a small sum of money annually to Government, and making what profit they can from the sale of the shells. Writing of the banks off Aripu, which have been, for many years, the sheet-anchor of the Ceylon fishery, Captain. P 110 Steuart observes that “ the number of successful fisheries obtained on the banks lying off the Aripu coast, more than on any other banks in the Gulf of Manaar, and the high estimation in which the pearls from these fisheries are deservedly held, would seem to indicate some peculiar quality in the bottom of the sea in these parts, which is favourable to the existence of pearl-oysters, and for bringing them to the greatest perfection. We know there is some- thing in the nature of the bottom of certain parts of the sea, which is favourable to the subsistence and growth of par- ticular fishes, and which improves the flavour for the food of mankind: for instance, the sole and the plaice caught in Hythe bay on the Kentish coast are esteemed better than those caught off Rye on the western side of Dungeness; and we also know that cod, turbot, oysters, and, indeed, most edible fishes are prized in proportion to tke estimation in which the banks are held, from whence they have been taken.” . In 1885 Captain Donnan attempted to cultivate the pearl- oyster on a coral reef, three miles from the shore, which was considered to be sufficiently far removed from the baneful influence of the Aripu river during the freshes. A tank for the reception of the oysters was dug in the centre of the reef, and surrounded by blocks of coral to form a barrier round its edge, heaped up high enough to be just awash at the highest tide. But the experiment failed, as, out of 12,000 oysters which were placed in the tank, only 27 remained alive at the end of seven months. ‘ Some of the oysters,” Captain Donnan writes, “ may have been washed out of the tank by the south-west monsoon sea, as it was not completely sheltered from the wash of the waves, but the bulk of them have, I believe, died off and been destroyed by some fish preying upon them. About 100 dead shells were found in the bottom of the tank, many of which bore evidence of having been bored and nibbled away. It is just possible that some fish may have got into the tank, and preyed upon the oysters, either by getting over the coral barrier around it, which would be slightly under water at high-water, or through the interstices of the coral underneath. The experi- ment so far has been a failure, and may be attributable to four causes :— *« (1) overcrowding the oysters in the tank ; (2) deficienoy of nourishment in water so near the surface ; 111 “ (8) destruction by fish, which had got into the tank, and preyed upon them ; “(4) by excessive agitation of the water in the tank during the south-west monsoon sea; or, pro- bably, to all these causes combined.” In March 1886 another experimental tank was made on a more sheltered part of the reef, and 5,000 oysters were placed in it. But, in the following year, all the oysters were found to be dead. The artificial cultivation of the pearl-oyster was attempted some years ago in a nursery made in the shallow muddy water of the Tuticorin harbour without success; and, in his final report to the Ceylon Government, Mr. Holdsworth expresses his opinion that there is no ground for thinking that artificial cultivation of the pearl-oyster can be profitably carried out on the Ceylon coast, as the conditions necessary for the healthy growth of the oysters are not to be found in the very few places, where they could be at all protected or watched. On the way to Captain Donnan’s tank, which we visited, we rowed over extensive banks of Alcydnians, of the luxu- riant growth and size of which only a very feeble idea is obtained from specimens as seen in museums. On the sandy bottom a large number of Echinoderms, solitary or clustered together, were clearly visible ; and, with the assistance of the divers and the dredge, the following species were procured :— Temnopleurus toreumaticus, a violet-spined Temnopleuroid, Oreaster thurstoni, Salmacis bicolor, Laganum depressum, Fibul- aria volva, Echinolampas oviformis, Holothuria atra, and Colo- chirus quadrangularis, These species, as also Oreaster lincki and Linckia levigata, which abound on the Muttuwartu Par, are all found on the opposite coast of the Gulf of Manaar. A single young specimen of Hippocampus was also brought up in the dredge. The tank, washed by the gentle swell, showed no signs of pearl-oysters, which had, doubtless, been smothered and disappeared below the surface of the bottom. But growing from the inner side of the barrier of dead coral which formed the wall of the tank was a fringe of living corals—WMontipora, Pocillopora, Madrepora, &ce. As these corals had grown in their present position since the construction of the tank, which was built up entirely of dead blocks of solid coral brought from the shore, the living corals on the reef being found to be too brittle to form a suitable wall, it was obvious that, as the tank was built in March 1886, the age of the corals did not exceed three years and 112 nine months. Accordingly I had the largest specimen of Montipora carefully detached from the dead coral-rock on which it was growing, and found that it measured 40 inches in length, 9 inches in height, and 16 inches in breadth, and weighed 17 pounds. After remaining at anchor for some days off Silavaturai, we started on the morning of the 10th for the western side of the great Chéval Par, which is known by the divers as kodai (umbrella) Par from the prevalence en it of a shallow cup-shaped sponge, Spongionella holdsworthi, which is sup- posed, by their imaginative brains, to resemble an umbrella. In a letter to Mr. Bowerbank, by whom this sponge was described,! Mr. Holdsworth stated that “‘ is only found on the 9 fathom line of the large pearl bank. It is attached to pieces of dead coral or stones. When alive it is of a dark brown; and when taken out of water it looks exactly like dirty wet leather.... ‘This sponge is so strictly confined to the locality above mentioned that its discovery by the divers is considered the strongest evidence that the outer part of the bank has been reached.” Another conspicuous sponge on this bank was the large, pale pink-coloured Petrosia testudinaria, which also lives on the Tholayiram Par. It was from the Chéval Par that, in 1888, about 150 millions of oysters, ripe for fishing, disappeared in the space of two months, between November and February. ‘This disappearance en masse was attributed by the natives to a vast shoal of rays, called Sankoody tyrica or Koopu tyrica, which is said to eat up oyster shells. But the more prac- tical mind of the Inspector of the pearl banks attributed the disaster—for such it was from a financial point of view—to the influence of a strong southerly current, which was running for some days in December—a current so strong that the Engineer of the Active had to let go a second anchor to prevent the ship from dragging. The divers, going down from the ship as soon as we were at anchor over the bank in 61 fathoms, reported abund- ance of young oysters, whose average breadth at the hinge was *75 inch, said by some to be three months, by others six months’ old, and brought up samples, from the rocky bottom interspersed with patches of fine sand, attached to dead coral, 1 Proc. Zool. Soc., 1873, p. 25, pl. v. 113 Melobesiz, sponges, and any other rough surface suitable for the attachment of the byssus. That the pearl-oyster prefers a rough to a smooth surface as an anchorage is shown not ouly by its usual habitat, but also by the observation that young oysters have been found clinging to the coir rope moorings of a bamboo, but not to the bamboo itself or the chain moorings. The number of young oysters on a small nodule brought up by the divers was counted, and found to be 180, scattered among which were 20 specimens of the little Suran. The prevailing stony corals on the west Chéval Par, brought up by the divers with dense clusters of young oysters adhering to them, belonged to the genera Porites, Astrea, and Cyphastrea, growing from a base of conglom- erated sand-rock, which is known by the divers as “ flat rock.”’ These corals, when broken up, proved a rich hunting ground for small crustaceans, tubicolous worms, and lithodomous mollusea. Very abundant on the bank were the bright-red Juncella ;uncea and the corklike Suberogorgia suberosa, on the axes and branches of which clusters of oysters were collected. At the time of his last inspection of the west Chéval Par in 1888, Captain Donnan found a large portion of it stocked with oysters one year old, which had, in the interval between the inspections, died from natural causes or been killed off, and replaced by another brood. The life of the pearl-oyster must be a struggle ,not only during the time at which it leads a wandering existence on the surface,! and is at the mercy of pelagic organisms, but even after it has settled down on the bottom, where it is liable to be eaten up by fishes, Holothurians, molluscs, &c., or washed away from its moor- ings by currents ; and comparatively few out of a large fall of “spat? on a bank can reach maturity even under the most favourable conditions. ‘ Much,” Captain Steuart writes, “appears to depend on the depth of water over the ground, and the nature and quality of the soil upon which brood- oysters settle, whether any portion of them eventually reaches the age of maturity. If the deposit be of small extent, or be thinly scattered, the young oysters are often devoured by fishes, before the shells are hard enough to protect them. But, when the deposits settle in dense heaps upon places 1 Young pearl-oysters have been found attached to floating timber and buoys, and to the bottoms of boats. 114 favourable for their nourishment and growth, many of them survive to become the source of considerable revenue.” How great is the struggle of the pearl-oyster for existence is very clearly shown by the records of the Tuticorin inspections, in which, time after time, a bank is noted in one year as being thickly covered with young oysters, and in the next year as being blank. Not, in fact, till a bank is thickly covered with oysters two years’ old can any hope be held out that it will eventually yield a fishery. Outside the west Chéval Par a sand flat extends for some distance north and south, from which the dredge brought up masses of coarse, broken shells, and, among other speci- mens, large numbers of Amphiorus and Clypeaster humilis, aud single specimens of Ophiothrix aspidota and