Subfamilies, Genera, and Subgenera — Recent and Fossil 155 



When the spire of Carinife.v becomes elongated the shell is dextral although 

 anatomically the animal is sinistral like that of Hclisomn. 



Animal. Resembling Helisoma in general form, but the tentacles are 

 shorter (see plate 34, fig. 1). 



ANATOMICAL CHARACTERISTICS 

 PLATE 34 {Carinijcx ponsorihyi E. A. Smith) 



GENITALIA. Male Organs (fig. 4). Seminal vesicle (SV) represented 

 by many short vesicles bordering the ovisperm duct for a length of 4.5 mm. 

 Sperm duct (SPD) long and narrow (2.5 mm. long), diminishing to less 

 than half its diameter as it joins the vas deferens, which is a tube of fine 

 diameter, 14-15 mm. long. The prostate (PRS) is elongated (3.5 mm. 

 long). A section, through the prostate and uterus (fig. 7) shows that the 

 ]:)rostate is peculiar in having the diverticula (14 in this section) occurring 

 laterally from a main pouch into which they empty and which, in turn, 

 empties into the sperm duct. There appears to be no special prostate duct 

 at each end, as in Helisoma. A section through the upper end of the prostate 

 (fig. 8) shows only 11 diverticula but the arrangement is the same. 



Penial complex (fig. 2). The preputium (PR) is elongated and sac-like, 

 4.5 mm. long and about 1 mm. wide at its greatest diameter. The vergic 

 sac (VS) is short (1.5 mm. in length) and there is no marked constriction 

 between the two sacs, as in Pierosoma. The musculature is different from 

 that feature in Helisoma. There are two sets of retractor muscles (RM), 

 one set, composed of two main branches with several small branches, is 

 attached to the vergic sac and the upper part of the preputium; the other 

 set, composed of two or more branching divisions, is attached to the upper 

 part of the vergic sac, with one branch connecting with a branch of the 

 first set. The vas deferens passes under this branch. There are three sets 

 of supporting muscles (S]\I) attached to the preputium. These are divided 

 several times in their attachment to tlie preputium and to the roof of 

 the mantle cavity. Several small muscles appear on the base of the 

 preputium below the first set of retractor muscles. 



Another specimen of ponsonbyi (plate 35, fig. 1) had a variation of 

 this musculature, there being but one main retractor in the first set, and 

 several narrow muscles, much branched, in the second set. The supporting 

 muscles (SINI) were also somewhat different. All specimens have a very 

 short (about 0.5 mm. long) penial gland duct on the outside of the penial 

 complex between the vergic sac and the preputium (DC). This duct does 

 not vary in any of the specimens examined. 



Internally (plate 34, fig. 3) , there are two fleshy pilasters in the 

 preputium (PL). These are shown in section in fig. 12. The penial gland 

 (01^) is an elongated, somewhat pyriform sac, narrowed at its junction 

 with the body wall of the preputium and enlarged at the cup-shaped cavity. 

 A section of the gland (fig. 10) shows many vertical glandular folds on the 

 wall of the cup and a number of pavement-like folds in the bottom of the 

 cup (IC). The gland duct (DC) extends into the cup and connects with 

 the vertical and pavement-like folds. The verge (V) is short and thick. 

 There is a muscular ridge or diaphragm (D) separating the cavity of the 

 vergic sac from the preputial cavity. 



Female Organs. The spermatheca (S) is about 1 mm. long, long-ovate 

 in shape and has a narrow duct (SD) almost 2 mm. in length, which enters 



