190(5.] MOLLUSKS FROM TJJE PERSIAN GULF. 803 



AvicuLA MARMORATA Pliil. { = Fterico Scop.) 



P.G. Ill two or three places found adhering in considerable 

 clusters to the telegraph-cable, at 50-55 fathoms, mud bottom ."jj , 



N.B. — Sevei'al immature Avicula', dredged at various dejoths, 

 occur in the collection, but none is capable of exact identificatiou . 

 One is allied to A. zebra Reeve, and may possibly he that species. 



Margaritifera imbricata (Reeve). { = Meleayrina Lam.) 

 P.G. Rare on the telegrajih-cable. 



Margaritifera margaritifera (L., 1 760). ( = Mehagr'ma Lam .) 

 Var. c. persica Jameson. 



P.G. & M.O. Generally distributed and foun<l on most rocky 

 patches. A curious young form occurred at Charbar, at 

 8 fathoms, in muddy sand. 



Di'. Lyster Jameson * gives the Bahrein disti'ict in the Persian 

 Gulf as supplying this species most copiously, and adds that it is 

 " called ' Bombay shell ' in the Pearl trade." 



Margaritifera muricata (Reeve). { = Meleagrina Lam.) 

 P.G. On the telegraph-cable, with M. imbricata Rve. 



Margaritifera VULGARIS (iSchum. 1817). { = jlleleagrina Lam.) 



Avicula fiicata Gould, 1850. 



P.G. The " Linjah " shell of the Persian Gulf, e. g. at Dabai, 

 adhering frequently to the telegraph-cable. This species, having- 

 its headquarters in the Arabian Sea, extends, according to Di-. 

 Lyster Jameson {I. c. pp. 385-386) to East Africa, Malay Pen- 

 insula, Australia, and New Gviinea. It is also reported from Japan 

 and New Zealand, being one of the most variable of all the peai'l 

 shells. M. margaritifera and this species are styled the Bomhay 

 and Ceylon Pearl-Oysters, respectivel}', by the traders. 



Mr. J. Oalcott Gaskin, Assistant Political Agent, Bahrein, kindly 

 supplied the following notes, which are well worth perusal here : — 



A Meviorandum on the Pearl-shells and Fearl-fishing Operations 

 in the Persian Gulf. 



There are three sorts of marketable shells found in the Persian 

 Gulf, viz. : — 



The Mother-o'-Pearl 



The Mussel. 



The Pearl-Oyster. 



Mother-o'-Pearl Shells. — The best Mother-o'-Pearl shells are 

 found round the islands near the Persian coast, piincipally at 

 Hinderabi, Shaikh Sliuaib, Kais Island, anrl Chira on the Persian 

 coast ; some are also obtained at Das, Karunein, and Zerukali 



* Proc. Zool. Soc. 1901. vol. i. p. 375. 



