106 A MANUAL OF AMERICAN LAND SHELLS. 



marked, sometimes suboval, sometimes subhexagonal, always longer 

 than wide. 



The jaw and lingual membrane (Plate V, Fig. I, of Terr. 



OMolL, V) have been described above. 

 The genitalia are figured on Plate XII, Fig. H. The testicle 

 is composed of black aciniform cteca; it is almost completely 

 buried in the upper lobes of the liver, the epididymis com- 

 p?ate™fp. pletely so, lying on tlie floor of the cavity foruied by the 

 Hemphiih g^^jj^.^j winding of the upper lobes. It appears to pass through 

 one of the lower lobes to join the oviduct, before reaching which it is 

 greatly convoluted. The accessory gland of the epididymis appears to 

 be composed of several aciniform cseca of unequal size. The prostate 

 gland is large. The vas deferens is extremely long, ten times as long 

 as the penis, and equals the length of the whole genital system. It is 

 attached to the side of the vagina, quite to the penis sac,, where it be- 

 comes free, and is spirally wound. It is largest about half way from 

 the vagina to the apex of the penis sac. It enters the penis sac at the 

 center of its truncated apex. The penis sac is very short and stout, 

 cylindrical, of equal breadth throughout. It has no retractor muscle. 

 The cloaca is very short. On the vagina, just above the penis sac, ap- 

 pears on some specimens an extremely small, sac-like organ, not figured 

 in the plate, as I am not entirely satisfied as to its presence. It is per- 

 haps a dart sac, or a prostate. The ovary has the usual tongue-shaped 

 form. The oviduct is not much convoluted. The vagina is long, and 

 extremely broad, several times convoluted. The genital bladder is oval, 

 small, with a short, stout duct entering the vagina at its upper extrem- 

 ity, by the side of the terminus of the oviduct. 



This peculiarly stout, cylindrical penis sac and broad vagina were 

 constant in eight specimens examined, all from Astoria. In several 

 other specimens from Mendocino County, easilv detected exteriorly by 

 a more slender, tapering body, and smaller, more rounded mantle, the 

 penis sac was found more elongated, the vagina less broad, the genital 

 bladder larger, with a more delicate duct. In these specimens, also, 

 the testicle was very much larger, and was not concealed in the liver, 

 but only slightly entangled in it at one point, against which it lay. The 

 epididymis in these specimens was also free from the liver. The geni- 

 talia of this form differ enough from those of the Astoria specimens to 

 warrant our belief in the existence of a second species of Prophysaon. 

 I have, therefore, figured also (Fig. I of Plate XII of T. M., V) thegen- 



