NATURAL SCIENCES OF PHILADELPHIA. 255 



9 



The vagina is very long, the penis enters it at its lower ex- 

 tremity near the exterior opening of the genitalia. 



For the stvke of comparison, we have also given figures of the 

 genitalia of two other Pacific subgenera, Arionta and Aglaja. 

 In Helix Townsendiana, Lea (Arionta), see plate I. fig. 4, we 

 detected the accessor^'- gland of the epididymis (3), composed of 

 several acini of different sizes. The genital bladder is lensrthened 

 oval (9), and differs greatly from that of Helix Neivberryana in 

 having a very short, stout duct. At the opening of the penis there 

 is a decided enlargement, perhaps of the nature of a prepuce, or 

 prostate. The vas deferens enters the penis below its apex. 

 The retractor muscle is at the apex of the penis. There seems 

 no accessory organ, the genitalia being reduced to their simplest 

 type. 



Of Aglaia we have examined two species, H. Jidelis, Gray, and 

 H. infumata, Gould. The genitalia of these are almost exactly 

 similar. In neither have we detected any accessory gland to the 

 epididymis. In both the penis is extended into a decided fla- 

 gellum (15). The vas deferens (7) enters below the flagellate ex- 

 tension (15). The retractor muscle (6) is attached on the oppo- 

 site side and still lower down. There is a well-marked prepuce 

 (12). Opposite the entrance of the penis on the other side of the 

 vagina, which is here considerably swollen, is a small sac-like 

 organ (14), ending in a smoothly rounded cul-de-sac, of what use 

 in the economy of the animal is unknown to us, unless it be a 

 rudimentary dart sac. There was no appearance, however, of a 

 dart within it. Just above this organ opens the stout duct of 

 another organ (13), cylindrical, bluntly pointed, hollow, of a 

 reticulated appearance. There is a contraction where this organ 

 joins its duct, which is of about the same size. The two together 

 are about as long as the penis with its flagellum, and stouter. No 

 dart was noticed within this organ. It is, no doubt, a form of 

 vaginal prostate, as described by Moquin Tandop. Tlie genital 

 bladder (9) is globular. Its duct is long, free in the upper half 

 of its course. The oviduct, ovary, genital bladder, testicle, etc., 

 of H. infumata, fig. 2, are not figured by us. They are as in H. 

 Jidelis, fig. 5, excepting the testicle, which is as in H. Newber- 

 ry an a. 



Fig. 4. Genitalia of Helix Towsendiana, Lea. Same reference 

 as in Fig. 5, excepting 3, the accessory gland of the epididymis. 



