ODOSTOMIA. 169 



C. Eulimella. 

 32. O. SciLL^^^ Scacclii. 



Melania ScUIcb, Scacchi, Notizie int. alle Conch, p. 51, no. 147. EuU- 

 ■ mella Scilke, F. & H. iii. p. 309, pi. xcviii. f. 5, G, and (animal) pi. FF. 

 f. 7, as Chcmnitzia M' Andrei. 



Body milk-white, microscopically speckled with flake-white : 

 snout gibbous in front, with an auricle or lobe on each side : 

 tentacles short, often folded inwards like a young and undeve- 

 loped leaf, protruded horizontally : ei/es small, black, placed 

 close together behind the tentacles : foot, long and broad, trun- 

 cated in front, with rather acute angles or corners, abruptly 

 ending behind in a minute point or tail. 



Shell forming a greatly elongated cone with a comparatively 

 broad base, rather solid, semitransparent and of a polished 

 lustre : sculpture none, except lines of growth ; the microscope, 

 however, shows an infinite number of excessively minute and 

 close-set spiral stria), which permeate the tissue of the shell 

 and are apparently connected with its structure : colon)', that 

 of glass in live specimens, becoming white in dead ones : spire 

 tapering to a rounded point ; nucleus exposed, twisted hori- 

 zontally across the top of the first regular whorl, and resembling 

 a young Spirialis retroversus: whorls 11-12 (exclusive of the 

 nucleus), gradually enlarging, flattened (especially on the 

 upper part), more or less angulated on the lower part and at 

 the base of the shell, which is remarkably depressed and con- 

 tracted inwards ; the last whorl occupies about one-third of 

 the shell : suture very narrow, slightly excavated, and nearly 

 straight ; it appears, like many of its congeners, edged by 

 a darkish band on the upper part of each whorl, owing to the 

 periphery of the preceding whorl being visible through the 

 partial transparency of the shell: mouth irregularly rhomboidal, 

 contracted above and expanded below ; length between a fourth 

 and a fifth of the spire : outer lip curved, except the upper side, 

 which shelves gently outwards a little below the periphery : 

 inner lip, a mere film on the upper slope of the base, somewhat 

 reflected and straight below: umhilicus usually none, although 

 the above-mentioned depression of the base sometimes produces 

 a small central cavity : tooth obscure, in one specimen like that 

 of 0. pusilla. L. 0-35. B. 0-1. 



Yar. compactilis. Shell thinner, much smaller, and not so 

 strongly keeled. L. 0-1. B. 0-03. 



* Dedicated to the memory of an Italian naturaUst and poet of the 

 17th century. 



VOL. IV. I 



