Achatinella and other Pulmonata. 347 



tooth, the side cusps being subobsolete. The lateral teeth are like the 

 centrals, but unsj-mmetrical. The marginal teeth are about as wide as 

 high, with one stout, pointed inner cusp, and two short, side cusps. 



Helix: provi^ioria, Pfr. (Thelidomns). 



New Providence, Bahamas (also Cuba). Gov. Rawson.* 



Jaw very slightly arcuate, wide, low, of about equal height throughout ; 

 ends blunt; anterior surface with 10-15 ribs, separated by irregular inter- 

 vals, not always reaching the cutting edge, which has a broad, blunt, 

 median projection. 



Lingual membrane with numerous rows of about 40-1-40 teeth, as 

 usual in the Helicidce, the marginals having one large and one side, small, 

 blunt cusp, projecting but slightly beyond the base of the tootli. 



O-landlna solillula, Pfr. (Oleacina). 



New Providence (also Cuba). 

 Lingual membrane as usual in the genus. 



JIiiliiiiu9n$l j<>ei)lllcralis, Poey (Leptomerus). 

 New Providence (also Cuba). 



Jaw stout, wide, low, arcuate, of about equal height throughout; ends 

 bluntly rounded; with'tifteen stout, broad, crowded ribs, their ends cre- 

 nellating either margin. Some of these ribs are of equal thickness 

 throughout their whole breadth, and are separated by decided narrow in- 

 terstices. The jaw cannot, therefore, be said to be in numerous plate-like 

 sections separated by narrow ribs, as is usual in BuUmidus. This jaw is 

 of interest as showing the passage from the jaw of Cylindrella, Bulimulus, 

 etc., to that of Helix, having some of the characters of each. 



Lingual membrane as usual in the Helicidce. Side cusps of centrals and 

 laterals obsolete, median cusp long, with a loug point, passing beyond the 

 base of the tooth. The upper margin of the centrals is incurved. Margi- 

 nal teeth a modification of the laterals, with one long, narrow, blunt, 

 inner denticle, and one or two short side denticles of similar shape. 



*Tl)e animals of this, the four following, and other Bahamas species were sometime 

 since received from Gov. Rawson by Bland, to whom the shells collected by the late Dr. 

 Bryant were referred by the Boston Society of Natural History. The jaws and lingual 

 membranes of the species were placed by Bland at tlie disposal of the society, and at 

 his suggestion were mounted for microscopic examination. We are indebted to the 

 Society for the use of the slide.^. 

 November, 1873. 24 Ann. Lyc. Nat. Hist, Vol. x. 



