1901.] MOLLUSKS FROM THE PERSIAN GULF. 403 



Columbella (Mitrella) astolensis, sp. n. (Plate XXIII. 

 fig. 4.) 



C. testa lavissima. nitida, anguste fusiform % , subpelluctnte ; anfracti- 

 bu$ octo, ajoieali obtuso, oceteris nequaqtiam ventncosis, stramineis, 

 infra, ju.vta suturas, albo et castaneo pellucide teeniatis etfasciatis, 

 alitt r (in typo) unicoloribits, in varietate undique castaneo obscure 

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

 infra medium ad basim l&niter spiralittr suhuloso ; apertura 

 ovata, labro perlcevi, nitido, iiicrassato, intus S-9-dcnticulato, 

 albido ; columella nitida, simplici, canal i lato. 

 Long. 7, lat. 2 mm. 



Hob. M.C. xVstola Island, 3 fathoms, sand. Charbar. 

 C. lincolnensis Reeve, from S. 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 network 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 

 sbould 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) blanda Sowb. 



P.G-. 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. 



Yar. candidans, nov. 

 Forma tit in typo, sed omnino albida, nitida. 



I. Karachi. An interesting immaculate form. 



Columbella (Mitrella) cartwrighti Melv. 

 P.G. Bahrein (Copt. Cartivright). Usually found at 7 fathoms; 

 muddy sand bottom. 



Columbella (Mitrella) dorIjE Issel. 



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

 Tryon, a var. of C. mindoroentia Rve. A doubtful specimen in 

 Townsend's collection. 



Coli'mi:i:li.\ (MlTBBLLA.) kuterpe Melv. 



I. Karachi, abundant. Bombay (Abercrombie). 



C»i. i Mi;u.i.\ ( .MiTKi;u.\ ) i'l.yviunka Melv. 



I. Bombay (Aberorombit). 



COLUMBILLi ( .M in: i.i.i- \ ) M \ im^UESA Gask. 



I. Bombay (Abercrombi. ). 



2r;* 



