1901.] MOLLUSKS FROM THE PERSIAN GULE. 373 



Fam. AdeokbidjE. 

 Adeorbis placens, sp. n. (Plate XXII. fig. 15.) 

 A. testa dejoressa, umhilicata, albo-vitrea, tenuissima, minuta ; 

 anfractihus quatuor, (qncali vitreo, nitido, undique concentrice 

 spiraliter temiistriatis, apud siduras paidlum impresso-excavatis, 

 ultimo rapide accrescente, circa umbilicum nitido, perlcevi ; 

 apertura rotunda ; peristomate vix incrassato, margine columellari 

 excepto, circa umhilicum triangulatim reflexo. 

 Alt. 50, diam. 1-50 onm. 



Hah. Gulf of Oman : lat. 24° 05' N., long. 57° 35' E. 205 

 fathoms. 



One of the minutest of a genus replete with " minutiora." We 

 should consider its nearest congener A. clausus Adams, from Japan ; 

 but this species, besides being less depressed, is more than double 

 the diameter. Several specimens occurred in the above locality, 

 and would appear to have attained their full growth. One indeed 

 bears the round bore-hole, showing its inmate had succumbed to 

 the attack of a carnivorous enemy. 



Yar. complajSTata, nov. 



Testa ut in typo, sed undique planata, nitida, perlcevi. 



Hah. Persian Gulf : E-ishire. 



Till more examples are obtained, we pi'efer considering this a 

 varietal form. It is possible that it is a nearly allied but separate 

 species. Upon one of the specimens before us of the type, we 

 have lately noticed absence of the usual striae round the inner 

 dorsal surface of the body-whorl. 



Adeorbis tanikoroides Mel v. 

 I. Bombay (^Ahercrombie). 



Pam. CerithiiDjE. 

 Cerithium adenense Sowb. 

 P.G. Bunder Abbas {M. F. Houssay). 



Cerithium bornii Sowb. 



I. Karachi. On rocks at low tide. 



Cerithitim c^ruleum Sowb. 

 P.G. Bushire. 



I. Karachi, with G. hornii. 



Cerithium olypeomorus Jouss. 

 P.G. Bunder Abbas (M. F. Houssay). 

 I. Karachi. 



Cerithium lemniscatum Quoy. 

 I. Karachi, along with C. bornii 



