1901.] MOLLTJSKS FROM THE PEEST AN GULF. 403 



CoLUMBELLA (Mitjbella) astolensis, sp. n. (Plate XXIII. 

 fig.4.) 



C. tesia Icevissima, nitida,angustefusiformi, subjoellucente ; anfracti- 

 bus octo, apicali ohtuso, cceteris neqiiaquam ventricosis, stramineis, 

 infra, juccta sutur as, alho et castaneo pellucide tceniaiis et fasciatis, 

 aliter (in typo) unicoloribus, in varietate undique castaneo obscure 

 reticulata, tcenia hie absente, illic obscure videnda, ultimo anfractu 

 infra medium ad. basim leniter spiraliter sulculoso ; apertura 

 ovata, labro perla^vi, nitido, incrassato, intus 8-9-denticulato, 

 albido; columella nitida, simplid, canali lato. 

 Long. 7, lat. 2 mm. 



Hab. M.C. Astola Island, 3 fathoms, sand. Charbar. 

 C. lincolnensis Eeeve, from 8. Australia, is considered by Mr. Pace 

 the nearest ally to this species. It is, however, nearly twice the 

 size, and though in one variety it assimilates in its markings to 

 our type, it is nevertheless far more variable in its range of pattern. 

 We have some examples which also exhibit a complete netvvoi'k of 

 chestnut reticulations, as in our variety above noticed. Apart 

 from the extreme difference in habitat, and the absence of any 

 known intermediates, we, with Mr. Pace, consider C. astolensis 

 should take rank as a good species, though we are bound to admit 

 the difference in size just mentioned — 12 mm. against 7 mm. — 

 furnishes the chief argument for its separation. 



COLUMBELLA (MiTRELLA) BLAND A Sowb. 



P.O. Gulf of Oman, lat. 24° 55' N., long. 57° 59' E. 

 30 fathoms, sand and mud. 



M.C. Occasionally near Gwadur and Ormara. 



I. Karachi. Not uncommonly from half-tide mark to 

 10 fathoms. 



Var. candidans, nov. 

 Forma ut in typo, sed omnino albida, nitida. 



1. Karachi. An interesting immaculate form. 



CoLUMBELLA (Mitrella) cartweighti Melv. 



P.G. Bahrein (Capt. Cartwright). Usually found at 7 fathoms ; 

 muddy sand bottom. 



CoLUMBELLA (MiTEELLA) DORIjE Issel. 



P.G. Bunder-Bouchir (Bushire) {M. F. Houssay). According to 

 Tryon, a var. of 0. mindoroensis Rve. A doubtful specimen in 

 Townsend's collection. 



CoLUMBELLA (MiTRELLA) EUTERPE Melv. 



I. Karachi, abundant. Bombay (Abercrombie). 

 CoLUMBELLA (Mitrella) elavilinea Melv. 

 I. Bombay (Abercrombie). 



CoLUMBELLA (Mitrella) marquesa Gask. 

 I. Bombay (Abercrombie). 



26* 



