Dentition of Pulmonata. 



29 



The prostate (4) is greatly developed. The penis sac (5) is short, cylin- 

 drical, entering the vagina near its base, and receiving both vas deferens 

 (7) and retractor muscle (6) at its apex. The genital bladder (9) is 

 small, oval, with a short duct (16) entering the vagina about the middle 

 of its length. The vas deferens (7) is swollen on leaving the prostate. 

 Testicle not observed. 



The marginal teeth of the lingual membrane are more of the type ot 

 Triodopsis than Mesodon, as known to us at present. I am in doubt, 

 therefore, of the subgeneric position of the species. 



Helix Wheatleyi, Bland. (Mesodon.) 

 Hayesville, N. C, Miss Annie E. Law. 



Jaw as usual in the subgenus, with about twelve ribs. 



Lingual membrane long. Teeth about G7-1-67. Centrals and laterals 

 as described under H. Clarki. Marginals high, narrow, with one very 

 Ion- cutting point to the single cusp. Outer marginals about as h.gh as 

 wide, with one long inner, obtusely pointed, cutting point, and one 

 shorter, outer cutting point. 



The first marginal teeth resemble those of H. thyroides in the single, 

 greatly produced cutting point. The extreme marginals, however, are 



bifid. , „ 



The genital system in the specimens received was too decayed to allow 

 of complete examination. The penis, however, was in perfect condition. 

 It forms the peculiar feature of the system on account of its enormous 

 development. It is short, cylindrical, with blunt ends, very stout, three 

 or four times as large as the oviduct, with retractor muscle, and vas 

 deferens at its apex. 



Helix Pennsylvanica, Green. {Mesodon.) 

 The upper portions of the genital system (pi. V, fig. VII) not observed. 

 The penis sac (5) is long and slender, with the vas deferens (7) and retractor 

 muscle (6) entering its apex, and its orifice entering the vagina near its 

 base The genital bladder (9) is long, stout, cylindrical, with a median 

 contraction-, its duct (16) is hardly distinct from it, with an entrance 

 opposite that of the penis sac. The prostate (4) is very large. 



Helix clausa, Say. (Mtsodon.) 



Ohio. 



PI V, fig. iv. The penis sac (5) is the conspicuous feature of the system : 

 it is longer than the oviduct, and almost as stout, of about equal size 

 throughout; it has the entrance of the vas deferens (7) and retractor 

 muscle (6) at its blunt apex. The genital bladder (9) is small, length- 

 ened oval, with a long, slender duct (16). The prostate (4) is narrow, 

 stout, prominent, cord like. The vas deferens (7) is large. The other 

 organs present no peculiar features. 



