32 SPOLIA ZEYLANICA. 



manned by a crew of six, one of whom filled the most necessary office 

 of baler. The boat, however, was roomy, and in consequence was 

 much more adapted to dredging work than the ordinary canoe. 



Since the investigations were conducted by means of divers 

 and with the dredge, the material collected did not include fishes 

 and other rapidly moving animals. The fishes will be worked out 

 in connection with a general survey of the marine and fresh-water 

 fishes of Ceylon, which I hope to commence in a few months. 



Generally speaking, the bottom fauna of the harbour is 

 richest in sponges, corals, and Holothurians. The shore collecting 

 is at present poor in the inner harbour, although it is exceeding^ 

 rich in the rock pools on the seaward side of the Ostenberg peninsula. 

 Mollusca and sea anemones are extremely rare. The sponge fauna 

 is surprisingly rich and varied. The specimens collected by me 

 have not yet been worked out, but I have obtained about thirty 

 species. The commercial sponge is rare. With the exception of 

 Alpheids, which were extracted from the sponge masses, the crusta- 

 ceans obtained were small in number, and consisted mainly of 

 Callianassids and Stomatopods, which also frequent the cavities of 

 sponges. Crustaceans are, however, a common feature of the fauna, 

 although very few were caught in the dredge. In the shallow water 

 at the north end of the harbour Peneids are very abundant, 

 especially Peneus indicus. 



Four charts of Trincomalee harbour are appended — 



(1) Giving the positions of the fifty-nine stations at which 



dredging and diving operations were conducted. 



(2) Giving the depths and nature of the bottom in various parts 



of the harbour. 



(3) Giving the present distribution of the Holothurians 



(trepang). It will be seen from this that the trepang is 

 more abundant in the northern half of the harbour, and 

 that it is almost completely limited to that part of the 

 harbour inside the 8-fathom line. 



(4) Givmg the distribution of sponges of all species. Practically 



no commercial sponges are present, but otherwise the 



sponge fauna is exceedingly rich and varied, and they 



occur within the 8-fathom line, on much the same 



ground as that occupied by the trepang. 



I give below an account of the results of the dredging. Many 



of the specimens still await identification, but sufficient information 



is available regarding depth, nature of bottom, and general fauna 



to guide the biologist in questions relating to the possibilities of 



Trincomalee liarbour in connection with the various schemes to 



which reference has been made above. 



January 17, 1911. 

 Station 1. — Three-quarter mile west of Little Powder Islands. 

 About 300 yards from sliore, half a mile from smallpox hospital. 



