1901.] MOLLISKS FROM TIIE PERSIAN GULF. 361 



aptly 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 (T. borealis Brod. & Sowb.), this species also having a 

 wide range in the far North, where T. coronata Gould, T. kroyeri 

 Phil., T. insignia Midd., and the conspicuous T. bicarinata Brod. & 

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

 habitats. T. clathrata A. Ad., comes froin New Zealand, aud 

 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- 

 carinata and T. gracilmta. These last we have not seen. 



Lippistes grayi A. Ad. (Separatista, Gray). 

 M.C. Charbar. Earely amongst shingle. 



Lippistes itelicoides Mtft. 

 Separatista cJiemnitzii A. Ad. 

 1. 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 Trichotropidce. 



Fam. Vanikorldje. 



Vanikoro cancellata Lam. 

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

 I. Karachi. 



Vanikoro clathrata Kecluz. 



Var. granulosa Kecluz (sp.). 

 P.G. Hindarabi Island. 



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

 intermediate forms. 



Var. cumvngiana Kecluz (sp.). 

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



Fam. Xexopik>i:ii» B. 



.\ i.nmj'iioh \ oobbug \t\ Beere. 



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

 7 fathoms, mud and stones. 



