26 rUOCEEDINGS OK THK M ALACOF.OG ICA T, SOCMOTV. 



IZab.—Gnlf. of Oman, lat. 24° 58' N., long. 56° 54' E., 156 fathoms. 



A smooth, umbilicate, globuLar species, the utnbilicar region being 

 excavate, thrice spirally lirate, decussate and crenulate at the points 

 of junction of the longitudinal lirse ; beyond these spiral lirations the 

 base is scratched with what may be lines of growth. 



Allied to C. fFatsoni, Tryon (Man. Conch., vol. x, p. 94, pi. xxxii, 

 figs. 81, 82), which was described by Boog Watson as sulcatum (Exp. 

 Challenger, vol. xv, pi. viii, fig. 11), but this name had been already 

 appropriated by A. Adams. 



21. Ctclostrema eupoiettim, Melvill. 



Cyclostrema eupoietum, Melvill : Proc. Malac. Soc, vol. vi (1904), 

 p. 159, pi. X, fig. 2. 



^«5.— Gulf of Oman, lat. 24°58'N., long. 56°54'E., 156 fathoms. 



A depressedly globular, very small species, closely spirally lirately 

 sulcate, umbilicus partly covered by the lingular peristomatal process. 

 Probably a member of this sectioa, but, the operculum and soft parts 

 being still unknown, also conchologically akin to Leptothyra, in the 

 family Turbinidae. 



Subgenus IV : DAROMA, A. Adams.^ 

 22, Cyclosteema subdisjunctum, H. Adams. 

 Cyclostrema subdis/unctum, IS.. Adams : Proc. Zool. Soc, 1868, p. 293, 

 pi. xxviii, fig. 8. 

 ITab. — Persian Gulf, Gulf of Oman, Maskat; 15 fathoms, muddy 

 sand and loose stones. Always local, the range of distribution is 

 a wide one, embracing Ceylon, to the Andaman Isles, at which last 

 place I have received it from the late Mr. George H. Booley, of 

 Port Blair. 



The large size, 10 to 12 millimetres in diameter, obliquely rude 

 contour, wide umbilicus, some spiral ribs, and, above all, the evolute 

 body-whorl, amply distinguish this very curious species. 



Genus MICROTHYCA, A. Adams.^ 



MiCROTHYCA CRENELLIFERA (A. Adams). 



Isander crenelliferus, A. Adams : Ann. & Mag. Nat. Hist., vol. ix 



(1862), p. 296, 

 Cyclostreyna {Microtheca) crenellifera, A. Adams : Sowerby's Thes. 

 Conch., vol. iii, p. 254, pi. 255, figs. 41, 42 (as Microthyca). 



Hah. — Bombay (A. Abercrombie). 



Originally described as from Japan, this very interesting form is 

 only known as Indian by one specimen found in shell-sand collected 

 near Bombay. We have but little doubt it is specifically the same, 

 being a shining white little shell, flattened and slightly angular above, 

 with wide spire, and crenulated round the umbilicar region. 



1 Sowerby's Thesaurus Conch., vol. iii (1864), p. 25^ 



2 Ann. & Mag. Nat. Hist., vol. xi (1863), p. 264. 



