262 EET. E. B. WATSON ON THE 



in the younger shells, has the suture less oblique and deeper, the 

 mouth is rounder, the pillar is not straightened nor the lip 

 flattened and produced at the base, the umbilicus is freer, even a 

 little larger, and the pillar-tooth lies a little higher on the body- 

 whorl. 



31. OnosTOMiA (Ttjebonilla) tjndata, n. sp. 



Shell cylindrical, strong, dull, pure white. Sculpture — Lon- 

 gitudinals strong, rounded, slightly oblique ribs, of which there 

 are 16 or 17 on the penultimate whorl, but they are dispropor- 

 tionately numerous on the last whorl, where tbey become narrower 

 and more crowded near the lip-edge ; on the base they are feebly 

 present, they are separated by strongish rounded furrows ; they 

 are traceable up to the tip, but not on the embryonic whorl; on 

 the later whorls one or two are varicose. Spirals : there are no 

 definite threads, but there is a very faint suggestion of close 

 superficial microscopic puckering extending to the whole surface, 

 but very obscure. Coloior a dull glossy deadish white. Spire 

 high, less conical than usual, that is broader in the upper and 

 narrower in the later whorls than most of the group. Apex 

 abruptly and somewhat squarely cut off", the extreme tip being 

 slightly immersed, leaving in profile a minute rounded dome. 

 Whorls 6, very equally rounded and loosely twisted, the last is 

 just I the total length of the shell. Suture rather deep, but 

 small and very little oblique. Mouth widely oval, bluntly pointed 

 above, slightly patulous on the base, rather more than a fourth of 

 the whole length. Outer lip not sharp, bent in but not sharply 

 at its junction with the body-whorl just below the periphery ; 

 its whole curve is very regular. Inner lip as a mere glaze and 

 very little obliquely it crosses the body, is scarcely angulated at 

 the pillar, down which it runs with a very sharp but barely pro- 

 jecting edge, and only at the extreme point of the pillar (where 

 it becomes faintly patulous and forms a slight angulation in 

 curving to the right) does the lip palpably project. There is no 

 umbilicus and no pillar-tooth. — H. 0*1 5. B. 0'05. 



Extremely rare. Two specimens are all I found ; they came 

 from the Gorgulho shore. 



At first sight this species is very like 0. clathrata, Jeftr., with 

 which Dr. Gwyn Jeffreys at first classed it, but afterwards 

 revised his opinion. That species is more transparent, less of a 

 dead white, is more conical, has smaller ribs with spiral striae, 



