808 BIESSRS. MELVILL AND STANDEN ON [NoV. 13, 



Amussium steindachneri Sturany. 



Avnussium steindachneri Sturany, Exped. S.M. Schiff 'Pola' in 

 das Rothe Meer (1899), p. 15, Taf. iv. figs. 9-12. 



P.G. With the preceding ; both equally abundant, mostly 

 dissociated valves. 



Also in the Gulf of Oman. Lat. 25° 19' N., long. 55° 10' E., 

 at 140 fathoms ; and lat. 24° 54' N., long. 37° 35' E., 205 fathoms. 



In both these last localities the specimens were large, perfect, 

 and highly coloured. We are indebted to the author (Dr. Rudolf 

 Sturany, of Vienna) for confirming our views as to these two very 

 interesting Amussia, first described from the Red Sea. 



Semipecten forbesianus (Ad. & Reeve). 

 Heini'pecten forhesianus Ad. & Rve. Yoy. of ' Samarang.' 

 I. Angrias Bank, in Bovuhdij [Capt. Thidall). Also occurring 

 in the Laccadive and Maldive Isles [Stanley Gardiner). 

 This shows an extensioii of range. 



Pecten crassicostatus Sowb. {Chlamys Bolten, 1798.) 

 P.G. Mussandam. Among large boulders at low tides, rarely. 

 Som.e authors propose to adopt Bolten's name now for the well- 

 known cognomen Pecten, reserving this latter for the section Vola. 

 Klein. 



Pecten ecus* Melvill, sp. n. (Plate LV. fig. 9.) 



P. testa ijarva, perlmvi, hyalina, alho-lactea, suhdAaphana, fere 

 rotunda^ valva dextra magis convexa, sub lente obscure concen- 

 trico-striata ; auriculis in sinistra subcequalibus, Icevibus ; 

 pagina interna hyalina, Icevi. 



Alt. 3-75. lat. 4, diam. 1-50 mm. 



Hab. Persian Gulf: Gulf of Oman. Lat. 24° 58' N., long. 

 56°54'E.; 156 fathoms, shell-sand. 



M.O. Lat. 25° 10' N., long. 60° 34' E. ; 40 fathoms. 



Of the same alliance as P. vitreus Chemn. and P. subhyalinus 

 Smith (' Challenger ' Rep.,vol.xiii. Lamell. p. 304, pi. xxii. figs. 2, 2 a) ; 

 but is smaller than either of these species, convex, perfectly smooth 

 excepting for very obscure incremental concentric lirge (visible 

 only with aid of a lens) on the left valve, the auricles being 

 quite smooth ; within, it is subhyaline and smooth. Both right 

 and left valves were equally abundant in the above dredgings, but 

 no perfect specimen has yet been seen. One example from the 

 latter locality exhibits slight traces of I'ufous coloration. 



Pecten flabelloides Reeve. 

 I. Karachi. 



Pecten layardi Reeve. 

 1. Karachi. 



Extending southward to Ceylon and westward to Aden [Com- 

 mander E. It. Shoplanul). 



* Eous, eastern. 



