CIONELLA. 



223 



Fig. 379. 



long slender corneous lamince, recurved at their cutting edges, 

 these plates partly lapping over 

 each other. 



Lingual membrane with 51 arched 

 TOWS of 13 — 1 — 13 teeth; plates 

 long and narrow, becoming nar- 

 rower as they approach the sides 

 of the membrane ; plates trans- 

 parent, denticles light horn-color, 

 central plate largest with one small 



denticle, laterals with two equally short rounded denticles, those 

 on the verge of the membrane having three minute denticles. 



Lingual dentition of 

 Punctum mimitissimum. [Morse.] 



Subfamily PUPIN^. 



Jaw small, slightly arcuate, with delicate perpendicular 

 strias, sometimes only visible on the margin ; concave margin 

 sometimes with a central projection. 



Teeth of the lingual ribbon uniform, short, bicuspid or 

 tricuspid. 



Fi?. 380. 



CIONEL.L1A, Jeffkets. 



Shell oblong-acuminate or ovate-oblong, striated or smooth, 

 shining ; whirls 6-7, the last rounded ; aperture oval, equalling 

 about one-half to one-third the shell's length ; columella short, 

 arcuate, more or less truncated, 

 peristome straight, often thick- 

 ened. 



Jaw slightly arched, slender, 

 furrowed with delicate, vertical 

 striae, its concave margin scarcely 

 denticulated. 



Lingual teeth arranged in transverse series, central tricuspid, 

 laterals bicuspid, uncini serrated. 



Jaw of Cionella suhcylindiica. 



OrthalicincR, as a distinct genus, for which Mr. Morse's name Punctum 

 might be retained ; otlierwise the species would be placed iu Hyaliua. 



