NATURAL SCIENCES OF PHILADELPHIA. 219 
H. Dupetithouarsi, not examined. 
Hi. ruficincia (pl. XIV., fig. 3), 835—1—35, with 18 laterals. 
HT. Gabbi, not examined. 
H. facta (see p. 216, fig. 60), 29 —1—29, with 11 laterals. 
He ielletia (pl. XMI., fis. 4), 57—1—577. 
Hi, Stearnsiana (pl. XIII, fig. 3), 50—1—50, with 24 laterals. 
Tle 22d tooth has the side cutting point. 
Subgenus GLYPTOsTOMA.! 
One species only is thus far known, Helix Newberryana. Its 
jaw (pl. XVLI., fig. 4) is low, wide, slightly arcuate, ends but little 
attenuated, blunt; cutting margin without median projection ; 
anterior surface with numerous (about 16), stout, separated ribs, 
deeply denticulating either margin. 
Lingual membrane (pl. XIII., fig.6) long and narrow. ‘Teeth 
44—1—47, with 17 perfect laterals. Centrals with the base of 
_ attachment long and narrow, with greatly expanded lower, lateral 
angles, the upper margin rounded, broadly reflected; reflection 
large, stout, with obsolete side cusps, but with decided, triangular 
side cutting points; median cusp very stout, short, with a long, 
acute cutting point reaching beyond the lower edge of the base of 
attachment. Laterals like the centrals, but unsymmetrical by the 
suppression of inner, lower, lateral angle of the base of attach- 
ment and inner side cutting point. The transition from laterals to 
marginals is marked by the lesser proportional development of the 
cusp and greater development of the cutting point. Marginals (c) 
low, wide, the reflection equalling the base of attachment and. 
bearing one inner, short, stout, oblique, blunt cutting point, and 
one outer, shorter, blunt cutting point. 
This species, like all others, has great variation in the develop-. 
ment of the cutting points on different parts of the same membrane. 
Subgenus EUPARYPHA. 
Jaw high, nntanntie, ends but little attenuated, blunt; cutting 
margin without median projection; anterior surface with a few 
(about 5 in Tryont) stout, separated, unequal tee deeply denticu: 
lating either margin. 
1 See Proc. Phila. Ac. Nat. Sci., 1878, p. 244. 
