Dentition of Pulmonata. 30 



Helix Traski, Newc. iArionta.^ 



Specimens from the mouth of San Tomas River, Lower 

 California, collected by Mr. Henry Hemphill. 



The genital system resembles very nearly that which I have figured 

 of Helix Nickliniana, Lea (Proc. Phila. Acad. Nat. Sci. 1874, 41, pi. iv. 

 fig. in). The duct of the genital bladder in this species is, however, very 

 much longer, its accessory duct shorter in proportion, the flagellum of 

 the penis sac longer. There is also a peculiar feature iu the genitalia of 

 H. Traski, a globular organ of about equal diameter with the vaginal 

 prostate, attached laterally to the flagellum of the latter, before it becomes 

 bifurcated. The bulbous expansions on the two branches of the flagellum 

 are also much larger iu H. Traski. It is figured in pi. VI, fig. IV. 



Helix Stearnsiana, Gabb. (Arionta?) 



To the kindness of Mr. Henry Hemphill I am indebted 

 for living specimens of this species from Todos Santos Island 

 and the month of the San Tomas River, Lower California. 

 The result of the examination of the genitalia and lingual 

 dentition establishes its specific distinction from the Cata- 

 liiia Island form (H. Kelletti, Forbes) to which it is nearly 

 related by the characters of its shell. (See L. and F. W. 

 Shells N. A., I, 176, 177). 



The genitalia (pi. VI, fig. ii) resemble very ifearly those of H. Kelletti 

 (Proc. Phila. Acad. Nat. Sci. 1874, pi. iii, fig. 4, p. 39). 



A comparison of the fignres, however, will show cousiclerable diflerence, 

 especially in the dart sac (14). In the species before me there is a long 

 thread like duct (14'' ) leading from the base of the dart sac (14) to a large 

 globular organ, whose character is unknown to me. Opposite the en- 

 trance of this duct a corresponding duct (14° ) branches out, but instead 

 of ending in a globular organ it becomes much enlarged in size and ends 

 in enveloping the prepuce (12). The dart sac (14) contained a small 

 dart of the form figured by Leidy (Terr. Moll. U. S., I) for Tebenno- 

 phorus Garoliniensis. 



The oviduct was closely and spirally wound around the duct of the 

 genital bladder. The testicle (1) and ovary (11) are yellow. 



The jaw is thick, arched, ends blunt, but little attenuated; anterior 

 surface with six stout, separated ribs denticulating either margin, and 

 several less developed, interstitial ribs. 



The lingual membrane is long and nari'ow'with about 50-1-50 teeth. 

 The centrals are of the form of those of H. Californiensis (L. and F. W. 

 Shells N. A., I, fig. 297). The cusp with its cutting point, however, is 



