NATURAL SCIENCES OF PHILADELPHIA. 2915 
incurved, its upper margin broadly reflected. The reflection is 
large and has subobsolete side cusps bearing well developed 
cutting points, and a short, stout median cusp, bearing a short, 
stout cutting point not quite reaching the lower margin of the base 
of attachment. The laterals are of the same general form as the 
Fig. 67. 
Lingual dentition of Bulimulus dealbatus. 
centrals, but are larger, broader in proportion, and are rendered 
unsymmetrical by the suppression of the lower inner angle of the 
base of attachment, and inner side cusp and cutting point. The 
marginal teeth (fig. b) are but a simple modification of the laterals, 
formed by the proportionally greater development of the reflection 
in comparison with that of the base of attachment, and the greater 
development of the cutting points. On the extreme marginals 
the cutting points are shorter and much blunter (fig. c). 
The dentition of Bulimulus alternatus is figured on p. 203 of 
L. and Frw. Shells, I. I have preserved no specimen from which 
I can more accurately draw the individual teeth. It has 75 rows 
of 37—1—37 teeth, all apparently of the same character as in B. 
dealbatus. 
I have not examined B. multilineatus, Dormant, Marielinus, 
Floridanus, patriarcha, Schiedeanus. 
ce. Jaw in numerous distinct pieces, sometimes soldered together above, 
free and imbricated below. Marginal teeth quadrate. ORTHALICIN&. 
Genus LIGUUS, Montf. 
Jaw thick, arcuate, ends rapidly attenuated, pointed ; composite, 
being in numerous, separate, free, imbricated, triangular pieces, 
with sutures inclined obliquely to the centre of the jaw, so as to 
leave an upper median, angular piece ; other 
pieces are soldered together above. Cutting 
edge with no median projection, serrated by 
the lower angles of the oblique pieces. For 
<j more detailed description see below, under 
Jaw of L. virgineus. Orthalicus, which has a similar jaw. I am 
