178 Jaw and Lingual Dentition of Pulmonata. 



Helix exoleta, Binn. (Mesodori). 



I have already referred to the peculiarity of this species in sometimes 

 having, and sometimes wanting, side cutting points to outer lateral teeth, 

 and a bifurcation to the inner cutting point of the marginals (see Proc. 

 Phila. Ac. Nat. Sc., 1875, 243). I here figure teeth from a lingual mem- 

 brane differing in this respect from that figured by me before (1. c. pi. xi, 

 fig. 7). The cutting point of the central and first lateral teeth have a lat- 

 eral bulging which represents the side point.* This poiut appears about 

 the 11th tooth. 



Plate xvi, fig. D. E. The 60th tooth is the last. 



Fig. E represents an inner marginal tooth from another membrane, 

 agreeing with my former figure in having a simple, not bifid, inner cutting 

 point. 



I am sure of the identity of each individual examined, having verified 

 it by the peculiar genital bladder and penis-sac, figured by Leidy, 1. c. 



Helix ruficincta, Newc. (Arionta). 

 Catalina Is!., California. Mr. Henry Hemphill. 



Plate xiii, fig. A, shows the genitalia. There are no peculiar acces- 

 sory organs, as in ramentosa, Nicklinia7ia, Kelletti, etc. (see Proc. Phila. 

 Acad. Nat. Sc, 1874, pi. iii, iv). A dart sac ? (d. s.) is, however, pres- 

 ent. 



Helix Carpenteri, Newc. (Arionta).- 



Coronaclo Islands, coast of Lower California. Mr. Henry 

 Hemphill. 



Genitalia as in H. »NickUniana (see Proc. Ac. Nat. Sc. Phila., 1874, pi. 

 iv, fig. 3). The flagellate ends of the vaginal prostate are shorter in 

 this species. 



Jaw as usual in the subgenus (see Proc. Ac. Nat. Sc. Phila., 1875, 216), 

 with over seven ribs. 



Lingual membrane long and narrow. Teeth 48 - 1 - 48, with 20 laterals. 

 See pi. xv, fig. B. It will be seen that the central and first lateral teeth 

 have no side cusps or cutting points ; it appears first on the 8th tooth. 

 The change from laterals to marginals is formed as usual, the inner cut- 

 ting point of the 21st tooth being bifid. A marginal is shown in the 34th 

 tooth. 



* I fear that in my figure of the dentition of M. albolabris (1. c.) I have mistaken this 

 bulging for a distinct cutting point. The membranes of all our species should be 

 carefully restudied with the view of learning whether there is any difference other than 

 of degree between this bulging and a distinct cutting point. The figures of Semper 

 (Phil. Archip.) should be carefully studied, as they show best the two planes of the 

 cusp and cutting point. 



