280 CRETACEOUS GASTROPODA 
1. Rrssomna ACUMINATA, Miiller, sp., Pl. XXV, Fig. 1. 
1851. Eulima acuminata, Miiller, Petref. der Aach. Kreidef., pt. II, p. 9, Pl. III, Fig. 8. 
Riss. testa elongata, aciculata, tenui, levi atque polita; anfractibus 9-10, sub- 
convexiusculis, ad suturam posteriorem paulo angustioribus, adpressis ; apertura 
ovata, postice acute angulata, antice dilata; labro extus paulo incrassato, antice 
simuose producto. 
Spiral angle 24°; sutural angle 12°. 
Height of aperture : total of shell eno (considered as 1:00) .. 0°30. 
Height of penultimate whorl : its width ( oD ont ea) oo OHS 
This interesting little shell is rather elongated, with a pointed apex, thin and 
perfectly smooth like a Hulima. The whorls are numerous, slightly convex, and 
along the posterior suture somewhat constricted. The basis of the shell is produced ; 
the aperture oval, pointed posteriorly, anteriorly broadly rounded and subeffuse ; 
the inner lip is thin and evenly curved; the outer lip externally, near the margin, 
slightly thickened, and anteriorly distinctly produced and somewhat enlarged. 
These last characters clearly mark the species as a Rissoina; it is closely 
allied to D’Orbigny’s &. incerta, though readily distinguished from it by its 
smaller height and the posterior constriction of the whorls. 
Prof. Miiller’s figure is very deficient, but I lately had an opportunity of 
examining the original specimen of this supposed Hulima, and was astonished to 
see it perfectly well preserved. This is partially evident from Dr. Miller’s des- 
cription, in which he draws special attention to the thin and translucent structure 
of the shell. In this respect the species can only be compared with the recent 
Riss. vitrea, Adams (Schwartz v. Mohr. loc. cit., p. 181, pl. 10, fig. 82), the 
shell of which is also quite smooth and transparent; it has, however, a larger spiral 
angle than ours. The recent species is from Jamaica. 
Locality.—In whitish sandstone near Comarapolliam ; only the specimen figured 
has as yet been found. 
Formation.—Arrialoor group. 
LX. KEILOSTOMA, Deshayes, 1848. 
Anm. s. vert. foss. de. Paris, 2me. edit. 1864, Vol. II, p. 422—Stoliezka, Sitzungsb. Akad. 
Wien, 1865, Vol. LII, Revis. ete., p. 20. 
2 
Char. Keil. testa elongata, turriculata, superficie sepissime sublevigata; aper- 
tura ovata, obliqua, imtegra, postice angustata atque subcanaliculata, antice truncata 
atque sub-effusa; marginibus junctis, intus levigatis; labro atque labio valde in- 
crassatis, primo antice lateraliter producto atque dilatato, altero valde calloso, late 
marginato ; columella solida. 
“This genus was proposed by Deshayes for the eocene Melania marginata, Lamk.,* 
(Keil, turricula, Brug. sp.) and the same author has since described (loc. cit.) from 
* Found also in the eocene beds of Sind and the Punjab. 
