124 Dentition of Pulmonate Mollusks. . 
Leptomerus sepulcralis, Poey. New Providence, Bahamas. 
Jaw stout, wide, low, arcuate, of about equal height throughout, ends 
bluntly rounded; anterior surface with 15 stout, broad, crowded ribs, their 
ends crenulating either margin; some of these ribs are of equal thickness 
throughout, and are separated by decided, narrow interstices; the jaw can- 
not, therefore, be said to resemble that usual in Bulimulus, though it seems 
to combine some of the characters of that and of the simply ribbed form 
of jaw. 
Lingual membrane as in B, chrysalis; no side cutting points to centrals 
and inner laterals. (Pl. XI, fig. J.) 
Leptomerus corneus. Nicaragua. Mr. McNiel. 
Jaw as in Bulimulus ; 15 ribs. 
Lingual membrane as in B. chrysalis. 
Rhinus durus, Spix. Brazil. J. G. Anthony. 
Jaw as usual in Bulimulus. 
Lingual membrane as in Bb, chrysalis. 
Plectostylus Peruvianus. Brug. Talcahuana, Peru. 
Jaw as usual in Bulimulus ; 30 ribs. 
Lingual membrane (PI. XII, fig. J) combining the characters of that of 
B. membranaceus in the marginals with those of B. chrysalis in the centrals 
and the five laterals on both sides of the median line; the cusp of the last 
is large, oblique, rounded. 
Bbulimulus Hdwardsi, Mor. lWLake ‘Titicaca. Prof. Alex. 
Agassiz. 
Jaw low, arcuate, ends rapidly acuminated, blunt; anterior surface 
with over ten distant ribs, some of the usual //elia type, others like the 
delicate ribs common in Cylindrella, Buiimulus, Goeotis. Amphibulima, ete. 
Lingual membrane (Pl. XI, fig. K) with 44-1-44 teeth. Centrals of the 
usual J/elicine type, tricuspid; laterals like centrals, asymmetrical, and 
consequently bicuspid. The change to marginals very gradual, and formed 
by the simple modification of the laterals. without any splitting of the inner 
cutting point. 
Subgeneric position of this species is unknown to me, as of the following. 
Bulimulus Gabbianus, Angas. Costa Rica. Dr. W. M. Gabb; 
formerly referred to B. Lrazuensts. 
Jaw asin bul. limneoides, but median ribs oblique ; there are about 32 
ribs. 
Lingual membrane with marginals as in B. Bahamensis, (Pl. XII, fig. L.) 
Cylindrella. 
Jaw arched, ends attenuated; very thin, transparent; dis- 
