GASTEROPODA OF THE UNITED STATES. 39 



composed of immature ova, polygonal cells with a germi- 

 nal vesicle and macula. 



The sides of the oviduct are soft, and in great measure 

 composed of a tissue consisting of large, polygonal cells, 

 "with from one to five small, round nuclei. 



The organ denominated genital bladder, from its open- 

 ing into the vagina, or at the termination of the latter, 

 and in Vaginulus from its belonging almost wholly to the 

 female organs, must be considered rather as a portion of 

 the female apparatus than a prostatic sac, as it is called 

 by Owen. By many authors, this has been termed the 

 spermatheca, from its supposed function of holding sperm- 

 atic fluid received from the male organs ; and with some 

 reason ; for in several instances I have found it to contain 

 a tenacious mass, which upon microscopic analysis was, 

 found to be composed of spermatozoa. This cannot, how- 

 ever, be considered wholly as its use ; for it secretes a 

 mucoid matter, which may probably facilitate the passage 

 of the ova through the vagina and cloaca. The mucoid 

 matter within the bladder is frequently found to contain - 

 immense numbers of an infusorial parasite, which I have 

 described under the name of Cryptoicus.^ 



The epithelium of the bladder consists of very long, 

 caudate, columnar cells, with elliptical, granular nuclei, 

 and a small, round nucleolus. 



» Journ. Acad. Nat. Sci. N, S. Vol. I. 



