1901.] MOLLUSKS from: IHE PERSIAN GULF. 361 



aptlj^ now bears. It is four-and-a-half whorled, the apex being 

 flattened and much depressed. Of the ten or twelve examples we 

 have examined, two only possess the epidermis ; this is dark fuscous, 

 covering the whole surface, and emitting a bristle at regular 

 intervals on the three spiral ribs, viz. at the point of junction 

 with the cancellations. The shell, when decorticated, is milky- 

 white, the surface to the base of the last whorl being entirely 

 cancellate, the interstices deeply alveate. Mouth somewhat square, 

 outer lip effuse; columella straightened down to the short truncated 

 rostrum. 



The genus is almost wholly Arctic or North Boreal, occurring 

 in Europe (r.6orm& Brod. & Sowb.), this species also having a 

 wide range in the far North, where T. coronata Grould, T. Tcroyeri 

 Phil., T. insignis Midd., and the conspicuous T. hicarinata Brod. & 

 Sowb., occur, though most of these are local, and restricted in their 

 habitats. T. clathrata A. Ad., comes from New Zealand, and 

 several N. Japan species have been described, the only ones from 

 absolutely tropical waters being T. migrans Dall, from Cuba, 

 while Mr. Brazier has also described two from N. Australia, T. tri- 

 cariiiata and T. graeilenta. These last we have not seen. 



LiPFlSTES GEATi A. Ad. {Separatista, Grray). 

 M.O. Charbar. Earely amongst shingle. 



LiPPISTBS HELICOIDES Mtft. 



Separatista chemnitzii A. Ad. 

 I. Karachi, dredged in fine condition. 



The position of this genus is not yet quite fixed, but it seems 

 to have a certain amount of affinity with the Trichotropiclce. 



Fam. Vanikoeid^. 



Vanikoeo cancellata Lam. 



P.Gr. Hindarabi I. Linjah, 3| fathoms. 

 I. Karachi. 



Vanikoeo clatheata Eecluz. 

 Var. granulosa Recluz (sp.). 



P.G. Hindarabi Island. 



Perhaps only a variety of V. cancellata Lam., as we have seen 

 intermediate forms. 



Yar. Gumingiana Eecluz (sp.). 

 P.G. Jask, on borders of Mekran Coast. 



Pam. Xenophoeid^. 



Xenophoea coeeugata Eeeve. 



P.Gr. M.C. Sparingly but generally distributed at about 

 7 fathoms, mud and stones. 



