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Dentition of Pulmonate Mollusks. 
cusps and no side cutting points, and with a very broad, short median cusp, 
Dearing a short, widely-expanded, square edge (as it cannot be called a 
point), Laterals like the centrals, but asymmetrical, as usual, and with an 
asymmetrical cutting edge larger than in the central tooth. The cutting 
edge becomes more developed as the teeth pass off laterally, in proportion 
to the base of attachment and the cusp also. Thus the marginals become 
formed without any splitting of the inner cutting point, or any development 
of a side cusp and cutting point, excepting that on some of the teeth a blunt 
obsolete side cusp may be shown. 
The form of this species from Gonave Island, Haiti, (Prof. Linden,) is 
said by Mr. Bland to have a white, instead of a reddish-brown, peristome. 
The lingual membrane is figured on Pl. IV, fig. H. The cutting points on 
all the teeth are more produced than in the Cuban sagemon and Arangiana ; 
after the eighth tooth there is a decided side cutting point on the. laterals 
and marginals. The jaw is the same as in sagemon. 
g : @ 
Caracolus Arangiuna, Poey. Cuba. Mr. Arango. 
Jaw (Pl. XV, fig. M) greatly arched ; ends blunt, scarcely attenuated ; 
cutting margin with a blunt, median projection. 
Lingual membrane (PI. IV, fig. 1) with 83-1-83 teeth, arranged as in 
_sagemon. The lower margin of the base of attachment seems delicately 
fringed. 
Caracolus marginella, Gmelin. Porto Rico. Mr. R. Swift. 
The jaw differs from that of the other species examined, in having stout 
anterior ribs. . 
Lingual membrane (PI. IV, fig. J). 
Leucochroa. 
The genus Leucochroa is adopted by von Martens, the type 
being Helix candidissima, Drap., a species whose anatomy has 
been described by Moquin-Tandon as being more nearly related 
to Zonites than to Helix. The genus is classed by von Martens 
among the Vitrinea, the section of Helicea containing the genera 
furnished with ribless anterior surface and median projection to 
the jaw, and aculeate, marginal teeth to the lingual membrane. 
Among the species catalogued by von Martens is Leucochroa 
Boissieri, Charp. We find, however, that both jaw and lingual 
membrane in this species indicate that the genus belongs to the 
ffelicea. 
Leucochroa Boissiert, Charp. Palestine. Mr. John Van 
Nostrand. 
Jaw very low, long, arcuate; ends but little attenuated, bluntly rounded; 
cutting edge with a decided median projection; anterior surface free from 
