330 CEYLON PEARL OYSTER REPORT. 



IAnguella cinerea, n. sp. Casella cincla, Bgh. 



Eexabranchus marginattts (Q. and G.). ( ' ratosoma cornigerum, Gray. 

 Iim-wlwis hibifrra (Am;.). ornatum, Bgh. 



Platydcris inframaculata (Aer.). Dons sp. ? 



speciosa (Abi;.). sp. ? 



herdmani, n. sp. Doriopsis awrea, Q. and G. 



,, (?) spinulosa, n. sp. Phyllidia varicosa, Leuck. 

 Halgerda punctata, a. sp. nobilis, Bgh. 



Thordisa (?) caudata, n. sp. jEgires villoms, a. sp. 



Chromodoris reticulatus, Pse. Trevelyana tricolor, A. and H. 



,, tenuilinearis, n. sp. Kalinga ornata, A. and H. 



It is, perhaps, premature to institute comparisons between the Nudibranch fauna 

 of Ceylon and those of other localities, as so little is known comparatively of the 

 distribution of the group in the warmer seas, and as the identification of spirit 

 specimens from written descriptions is attended with great uncertainty. 



The capture of four species of Eolids and a Doio on the hanging oyster cages is ot 

 interest, as it seems to show that absence or rarity of these families in tropical seas 

 is, perhaps, due more to the difficulty of finding them than to their actual scarcity, 

 the larger and more showy Dor ids attracting the attention of collectors to the 

 exclusion of more insignificant forms. 



There has been but little work done in the past on Ceylonese or Indian 

 Nudibranchs. Dr. Kelaart, in 1859 (3) (4), described 33 species of Doris from 

 specimens collected in Ceylon, but his descriptions are based mainly on the colour and 

 texture of the living animal. Alder and Hancock (5), in examining a collection of 

 Nudibranchs from Madras, re-discovered six of Kelaart's species with the aid of his 

 original drawings, and added 32 more, besides recording three others previously 

 described. 



Of more recent works should be mentioned a paper by Collingwood on Nudi- 

 branchs from the Eastern seas (8) and a list of the Dorididse in the British Museum 

 Collections bv Abraham (7), who there describes the external characteristics of a 

 number of spirit specimens. Reference should also be made to the work of 

 Sir Charles Eliot, who has published papers on the Nudibranchs and Tectibranchs 

 of Samoa, the Maldives and Laccadives, and East Africa (11) (12) (13). 



Most, however, of the adequate descriptions of Oriental Nudibranchs are due to 

 the long-continued work of Dr. Rudolph Bergh, culminating in the magnificent 

 series of papers in Semper's ' Reisen im Archipel der Philippines' 



In working out the collection no attempt has been made to investigate the anatomy 

 of the specimens beyond what seemed to be necessary for their identification. 



In conclusion, I should like to express my thanks to Professor Herdman for his 

 kindness in allowing me to work out this collection and use his notes, and for the 

 facilities which he atforded me, and also to Mr. E. A. Smith for kindly allowing me 

 to examine the Nudibranchs preserved in the British Museum Collections. 



