2 



Melvill, Descriptions of Marine Mollusca. 



(L. exilis Sowb.), a handsome Pecten (P. Townsendi 

 Sowb.), and some very pretty Trochidce, Bidlice, and other 

 Mollusca.* 



Mr. Townsend's collection abounds in species not yet 

 satisfactorily named. Many, especially amongst the 

 Pelecypoda, are juveniles, and for identification, therefore, 

 not in good condition ; others are mature, but obscure in 

 themselves. Amongst such are many small Pleurotomidce . 

 However, as the following paper will show, there are 

 amongst them some very fine and unequivocal addenda 

 to Molluscan species, the most conspicuous, perhaps, 

 being the Mitra (Costellaria) stephanucha, a giant of its 

 section, and which Mr. Townsend has just discovered in 

 greater plenty than when the first specimens came to 

 light. The beautiful Scalaria fimbriolata is also note- 

 worthy, a large Tapes, and a Yoldia, of which the forms 

 known hitherto are arctic rather than tropical. 



We believe it to be Mr. Townsend's intention to 

 publish sooner or later a complete summary of the species 

 obtained in his various dredging expeditions in this 

 locality, or, rather, series of localities between long. 50° 

 and 70 0 . 



This catalogue, when fully worked out, will be found 

 to contain several hundred species, and will be the most 

 important contribution towards the Mollusca of the 

 North-west Indian Ocean (embracing the Persian Gulf, 

 Sea of Oman, and the Arabian Sea) that has been written 

 within recent years. 



Combining and connecting, as this vast region does, 

 the fauna of the Red Sea and Aden with that of Bombay 

 and Ratingiri, and, still further south, Ceylon, it is not 

 surprising to find that several species hitherto thought 

 peculiar have extended their range. Only very recently, 

 when describing certain new marine shells from Bombay, 



* Vide Proc. Mai. Soc. Loud., Vol. I, pp. 160 , 214, 278. 



