157 



the fauna to be rather uniform over the whole area. Thus I have made only a few dredg- 

 ings in 20 — 30 fathoms — except at Koh Kram and Koh Cluien — and my researches 

 are mainly restricted to near the islands named and the Gulf of Rayong , where 1 have 

 made several dredgings on the way between Koh Chang and Koh Chuen. 



The richest parts of the collections are the Fishes, Crustaceans, Mollusks and 

 Porifera. Echinoderms were less numerous than I had expected ; thus for inst. only one 

 species of Crinoids was found (whereas I found 4 — 5 species on a coral-reef at Singa- 

 pore). Of Fishes I got a very large number in the fishing-stakes of the natives at Koh 

 Kong and in the mouth of the river Paknamwen. An otter-trawl which I had brought with 

 me, was used several times most successfully from <'Chamroen» , till it was lost in the 

 mud. In the dredge fishes were often taken, but of course not in such vast numbers 

 as in the trawl. 



A very rich fauna was found in the coral-blocks: Annelids, Gephyreans, Crustaceans, 

 Ophiurans and boring bivalves were taken in large numbers, when the blocks were broken 

 to pieces. A most important part of this peculiar fauna is formed by the Porifera. All 

 the holes in the coral-blocks, which were not inhabited by other animals, were filled out 

 by fleshy, and mostly flesh-coloured or white sponges ; but especially the underside of the 

 blocks was covered by mostly incrusting sponges of the very beautiful colours — red, 

 blue, yellow, green, black, in all variations — a most pleasing sight. 



Besides the marine fauna also the interesting animal life in the Mangrove was 

 carefully studied, as well as the fauna on the muddy coasts of the sound, which proved 

 to be of no small interest. — Also collections of the terrestrial fauna were made, though 

 by far the most weight was laid on the marine researches. Some of the lower Arthropods 

 have turned out to be most interesting, especially several species of Pauropus, Scolopen- 

 drella and Koenenia. 



To give a more detailed account of the animal life in the Mangrove, on the 

 coasts, in the coral-blocks etc. would be very interesting. This, however, must wait till the 

 collections have been worked out. 



On the 21 s ' of March 1900 we left Koh Chang, and on the 1 st of June we arrived 

 at Copenhagen on S.S. "Cathay» of the East Asiatic Co. 



I may now be allowed to express here my best thanks to the Danish Government 

 and the Carlsbergfond for supporting the working out of the collections, and to the Royal 

 Danish Society of Sciences for publishing the scientific results of the Expedition. 



Th. Mortensen. 



