FERUSSACIA. 187 



Lingual membrane as usual in the Heiicca. PI. IV. Fig. R, as well as that 

 of the jaw, I drew from a Maine specimen, furnished by Mr. Anson Allen. 

 There were 24 1 24 teeth, with 8 perfect ?\s 94 



laterals. The central teeth are small and 

 narrow in proportion to the laterals, with a 

 long, narrow base of attachment, expanding 

 at its lower angles. The reflected portion is Jaw of F - 



very small, tricuspid ; the central cusp stout, short ; the side cusps small, blunt ; 

 all the cusps bear short cutting points. 



The lateral teeth are about as wide as high in their base of attachment, 

 which is subrectangular. The whole upper edge is squarely reflected. The 

 reflection is very short, and bears a stout, blunt, long, inner cusp, reaching al- 

 most to the lower edge of the base of attachment, and bearing a long, blunt 

 cutting point, which reaches beyond the lower edge. The outer side cusp of 

 the reflection is widely separated from the inner cusp, is very short, bluntly 

 rounded, and bears a short, blunt cutting point. The first marginals (Fig. 6) 

 are but a modification of these laterals, by the greater development of the re- 

 flection, and shortening of the inner cusp. The outer marginals (Fig. c) be- 

 come wide, low, irregular in shape ; the upper edge broadly reflected, the 

 reflection reaching the lower edge of the base of attachment, and bearing along 

 its whole length numerous (6 or 8 in some teeth) short subequal denticles, some 

 bluntly rounded, others longer and sharp, giving a pectinate appearance. 



Ferussacia subcylindrica, LINN. 

 Vol. III. PI. LII. Fig. 4. 



Shell small, thin, transparent, oblong-oval ; epidermis smoky horn-color, 

 smooth, very bright and shining ; whorls 5 or 6, somewhat rounded, the last 

 equalling two fifths the shell's length, rounded at base ; apex obtuse ; suture 

 somewhat impressed ; aperture lateral, oval, its plane nearly parallel with the 

 axis of the shell ; peristome simple, thickened, often slightly rufous ; umbilicus 

 imperforate ; columella obsoletely truncated at base. Length, 6 mill.; diameter, 

 2| mill. ; aperture, 2| mill, long, i mill. wide. 



Helix subcylindrica, LINN., Syst. ed. XII., II. 1248 (1767). Not MONT. 



Helix lubrica, MULLER, Verm. Hist., I. 104 (1774). 



Hulimus lubricus, DKAPAKNAUD, Moll., 75, PI. IV. 24. GOULD, Invertebrata, 



193, Fig. 124 (1841). ADAMS, Shells of Vermont, 157 (1842). DEKAY, N. 



Y. Moll., 55, PI. III. Fig. 43 (1843). BINNEY, Terr. Moll., II. 283, PI. LII. 



Fig. 4. 

 Achatina lubrica, PFEIFFER, Mon. Hel. Viv., II. 272. "VV. G. BINNEY, Terr. 



Moll., IV. 138. 

 Zua lubrica, LEACH, Moll., p. 114. GRAY, Man., 188. REEVE, Brit. L. & 



Fr.-W. Sh., 93 (1863). 

 Cionella lubrica, JEFFREYS, Linn. Trans., XVI. 327. 



