GASTEROPODA OF THE UNITED STATES. 27 



latter with the duct of the generative bladder, where it 

 receives a small duct from the duct of the latter organ, 

 and then passes nearly to the external female orifice, 

 where it turns abruptly forwards between the muscular 

 peritoneum and the right edge of the podal disk, and 

 continues this course to the head. It now turns abruptly 

 backwards to the right, and again appears within the 

 visceral cavity, and passes to the base of the penis. 



The penis is a conico-cylindroid, contorted organ, con- 

 tained within a thin, muscular sheath. Its apex presents 

 a small, round papilla, or glans ; and into its base is in- 

 serted the retractor-muscle, which arises just anterior to 

 the pulmonary cavity. The lower part of the preputial 

 sheath of the penis is joined by the common duct of a 

 highly developed, multifid vesicle. This latter organ 

 consists of twenty-five long, narrow, cylindrical. Wind 

 tubes, contorted at their termination, and opening separ 

 rately into a common tube, containing, in the specimen 

 examined, attached to its bottom, a narrow, cylindroid 

 organ, which, probably, may have been an uncalcified 

 dart. 



The tube formed by the pragputium and the duct of 

 the multifid vesicle, as previously mentioned, opens ex- 

 teriorly immediately beneath the mouth. The ovary is 

 small and unusually lobulated. The oviduct is a narrow, 

 cylindrical tube, which winds forwards and then back 

 again so as to form a double spiral, after which it makes 

 a curve downwards, and is joined by the duct of the 

 generative bladder. The latter organ is globular ; its 



