5 101 



On comparing the LameUihranchiala hitherto descrihed from the Gulf of Siani 

 with those of other more thoroughly investigated parts of the Asiatic waters, we 

 lind, according to Melvill & Standen, that 426 species (among which are many 

 deep water forms) are recorded from the Persian Gulf, the Gulf of Oman, and the 

 Arabian Sea. Besides the fact that this fauna has many species in common with that 

 of the Gulf of Siam, the two faunas correspond in many points with each other in 

 regard to character. Unfortunately, J. G. Hidalgo's work on the Lamellibranchiata of 

 the Philippines is not yet finished, so no definite number of species can be recorded 

 from that place. In Casto de Elera's uncritical -'Catàlogo sistemàt. de toda la 

 Fauna de Filipinas,' III, 1896, more than 800 Lamellibranchiata are recorded from 

 the Philippines. From Japan, Pilsbry gives in 1895 over 500 species in his "Cata- 

 logue of the Marine Mollusks of Japan," and he has afterwards added several 

 to these. 



The new species and varieties which will be described in the following 

 pages are; — 



Area (Barbalia) Siaiuensis. 



— (Anadara) Mortenseni. 



— (Scapharca) clichotoina Desh. var graiiosa. 

 Carditella pusilla. 



— pulcbella. 

 Liicina (Phacoides) Dalli. 



— [Phacoides) pulchella. 

 Kellija lineata. 



— rosea. 



— vilrina. 



— elongala. 



— lilium. 

 Montaciita costata. 



— nenusta. 



— (Tellimiia) imriabilis. 



— (Tellimya) riidis. 

 Tellina {Arcopagia:') Smitbi. 



— (Merisca) Martensi. 



— [Moerella) Berghi. 



— (Macoma) temiiscalpta. 

 Circe Melrilli. 



Chione [Timocleu) Siamensis. 



Hemicardium {Fragiim) fragum L. var. carinata. 



Corbula lineata. 



— arcaeformis. 



— (?) mirabilis. 

 Sphenia quadrangularis. 



