5 101 
On comparing the Lamellibranchiata hitherto described from the Gulf of Siam 
with those of other more thoroughly investigated parts of the Asiatic waters, we 
find, according to MEtvitt & 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. H1patGo’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 pe ELera’s uncritical “Catalogo sistemat. de toda la 
Fauna de Filipinas,” III, 1896, more than 800 Lamellibranchiata are recorded from 
the Philippines. From Japan, Pinspry 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: — 
Arca (Barbatia) Siamensis. 
— (Anadara) Mortenseni. 
— (Scapharca) dichotoma Desh. var gratiosa. 
Cardttella_ pusilla. 
— pulchella. 
Lucina (Phacoides) Dalli. 
— (Phacoides) pulchella. 
Kellya lineata. 
— rosea. 
—  vilrina. 
— elongata. 
lilium. 
Montacuta costata. 
= venusta. 
(Tellimya) vartabilis. 
— (Tellimya) rudis. 
Tellina (Arcopagia?) Smitht. 
—  (Merisca) Martensti. 
—  (Moerella) Berghi. 
-- (Macoma) tenutsculpta. 
Circe Melvilli. 
Chione (Timoclea) Siamensis. 
Hemicardium (Fragum) fragum L. var. carinata. 
Corbula lineata. 
—  arcaeformis. 
— (2?) mirabilis. 
Sphenia quadrangularis. 
