40 PROCEEDINGS OF THE ACADEMY OF 



where the flagellum commences. The retractor muscle is inserted 

 half way between the vagina and the entrance of the vas deferens. 

 Opposite the mouth of the penis sac is a small sac-like organ, 

 probably a dart sac or vaginal prostate. 

 Helix Mitchelliana, Lea {Mesodon), pi. III., fig. iii. 



The genital system is long and narrow. The oviduct is greatly 

 convoluted. The penis sac is long, stout, cylindrical, with a bulb- 

 like expansion at its apex, at which point both vas deferens and 

 retractor muscle are inserted. The genital bladder is lengtiiened, 

 ovate, not much larger than its duct, which is short, and enters 

 the vagina below the middle of its length. 

 Helix reticulata, Pfr. (Arionta), pi. III., fig. ii. 



The specimens examined have a very globose shell. The ovary 

 is brownish below, yellowish above. The epididymis and testicle 

 are salmon colored. The oviduct is w'hite, the prostate salmon. 

 The genital bladder is small, oval, with an extremely long duct, 

 which has a flagellate branch. The duet enters at the lower end 

 of the vagina. The penis is narrow, cylindrical, extremely long, 

 with a flagellate extension. The retractor muscle is inserted be- 

 yond the middle of the length of the penis, the vas deferens at 

 the commencement of the flagellum. There is a stout long cylin- 

 drical vaginal prostate, whose apex is extended into a flagellum, 

 which shortly becomes bifurcate, there being a bulb-like expansion 

 on each branch just beyond the bifurcation. 



In some individuals the bulb-like expansions are still larger and 

 stouter than in the figure. The cylindrical extension of the va- 

 ginal prostate is abruptly truncated, the two flagella entering near 

 the end, not at the extreme terminus. 



Helix Roemeri, Pfr. (Mesodon) . 



The genitalia are figured on pi. lY., fig. v. The oviduct is 

 scarcely convoluted. The genital bladder is large, oval, with a 

 long, large duct. The penis sac is short, stout, of about equal 

 breadth throughout, ending in a stout oval bulb, into which the 

 vas deferens enters. The retractor muscle is inserted above the 

 entrance of the vas deferens. 



The specimen examined was collected in Bosque Count}', Texas, 

 by Mr. Hugo W. Ericsson. 

 Helix appressa, Say ( Triodopsis) . 



The genitalia are figured on pi. IV., fig. iv. The ovary is long 



