45 



DESCRIPTION OF A NEW SPECIES OF ADEORBIS. 



By J. R. LE B. TOM LIN, M.A. 



(Read before the Society, March 12th, 1913). 



Adeorbis platymma^ n.sp. (pi. i., f. 12). 



Shell much flattened, elliptical in shape, disk-like, acutely keeled, 

 thin, white, with extremely fine, close and not very evident spiral 

 sculpture; hroadly and profoundly umbilicate; periphery simple; 

 spire small, and but slightly projecting; whorls 4I in number, 

 the last occupying most of the shell ; aperture very large ; 

 columella very straight, forming a chord to the circular outline 

 of the lip ; base convex, marked with more or less concentric 

 lines of growth which are much plainer in the young shell than 

 in the adult. 



Diam. max. 4 mm.; diam. min. 275 mm. 



Alt. I "25 mm. 



Aperture — diam. max. 275 mm.; diam. min. 2 mm. 



Hab.: Singapore (Archer). 



Type in Brit. Mus. (Nat. Hist.). 



In form this shell somewhat resembles planulata^ Sow. from 

 the Cape (described as a Cyclosirevid) and angasi^ A.Ad., in fact 

 Tryon^ records these Singapore shells as aiigasi. A. plaiymma is, 

 however, easily distinguished by the absence of crenulation on 

 the periphery. From planidata Sow. it differs by its shape, which 

 is not circular, its convex base, by the absence of a raised line 

 round the umbilicus, and by the character of the sculpture on the 

 upper side, which consists of extremely fine and close lines. 



1 7rXttTi/;ti/ia, a flat cake. 



2 Mar. Shells S. Afr., p. 46, pi. 2, f. 49. 



3 P.Z.S. 1863, p. 424, pi. 37, figs.- II, 12. 



4 Manual, vol. x, p. 86. 



Clausilia rolphii (Leach) in Salop.^In May of this year (1912), while 

 visiting Linley Woods in Salop with the British Mycological Society, I had the 

 good fortune of finding a solitary specimen of Clausilia rolphii (Leach). C. latniii- 

 ata Mont, was plentiful in the same wood. C. rolphii has not previously been 

 recorded from this county, and it seems likely that careful search would reveal 

 its presence in parts of Worcestershire lying between Linley (which is not far 

 from Bridgnorth), and its well-known stations in Gloucestershire. Mr. E. W. 

 Swanton has kindly identified the shell for me. — N. G. Hai:)DEN {Read before the 

 Society, December lith, 1912). 



