Subfamilies, Genera, and Subgenera — Recent and Fossil 63 



diverticula (fig. 10, PRS, fig. 8). The i)rostate duct is a narrow tube about 

 1.5 nnn. long from the prostate to its junction with the sperm duct to form 

 the vas deferens (fig. 10, PD, SPD). In the natural position the prostate 

 lies over the sperm duct and until separated from this organ the prostate 

 diverticula appear to be directly attached to the sperm duct (see fig. 8, 

 PD). This junction is placed higher uj) on the uterus than in Planorbis or 

 Anisus. The vas deferens is a long (4.5 mm.) narrow tube which enters the 

 vergic sac without enlargement. 



The penial complex (fig. 9) is very long and narrow, the prcputium 

 (PR) being a little more than half the length of the vergic sac (preputium 

 1.3 mm. vergic sac 2 mm.) . The narrow and cylindrical vergic sac is greatly 

 contracted for about a third of its length near its connection with the 

 preputium. There' is one long and narrow retractor muscle attached to the 

 summit of the preputium. Internally, the anatomy of the penial complex 

 is the same as in A?nsiis. 



Female Organs, The spermatheca is cylindrical, 1 mm. long, attached 

 to the vagina by a narrow spermathecal duct a little more than 1 mm. long. 

 The vagina (V) is very short (0.3 mm.) and wide. The uterus (U) is long 

 (2 mm. long, 0.2 mm. wide) and narrowly cylindrical. The nidamental 

 gland (XG) is long (about 3 mm.) and of larger diameter than the uterus 

 (about 0.3 mm.). The oviduct (OD) is long (about 4 mm.) and narrowly 

 cylindrical. The albumen gland is about the shape of that organ in Anisus 

 (see plate 7, fig. 2). 



Hermaphrodite Organs. The ovotestis is like that organ in Planorbis 

 and Anisus. The diverticula are long and cylindrical and packed closely on 

 the ovisperm duct (plate 3, OT, fig. 7). The ovisperm duct lies at each end 

 of the seminal vesicle, of about the same length in each division, (about 2 

 mm.) and is a small, smooth tube (SO). 



The figure in Germain (1931, pp. 521, 532) does not agree with the 

 Poland specimens in all respects. The penial complex (p) shows the vergic 

 sac as much swollen, while in the specimens examined it was long and 

 narrowly cylindrical. The relative lengths of the female and male systems 

 is shown much shorter than was observed in the Poland specimens. Details 

 of the prostate and ovotestis are not shown. The spermatheca in both 

 figures is the same. 



Soos's figure (1917, p. 47) is similar to the ones here presented and is 

 somewhat clearer than those of Germain. The prostate shows the great 

 number of short diverticula, the spermatheca is on a long duct, and the 

 penial complex is like the Poland specimens here figured. 



Respiratory and Renal Systems. The pseudobranch (jilate 3, fig. 5. P) 

 is about as in Anisu>i, but is smaller and narrower. The pneumostome (PS) 

 is larger than in Anisus but is otherwise similar. 



The kidney (plate 46, fig. 19) is long and narrow (7 nnn. long, 0.5 mm. 

 wide) with a sharply reflected ureter. A cross section of the kidney (fig. 

 20) shows a laterally jiyriform lumen with the veins at about the center of 

 the section at each end. There is no ridge on the ventral side of the kidney 

 but there is a rounded bulging on the left side that does not appear on 

 the right side. 



Digestive System. The stomach (plate 48, fig. 8) is greatly elongated, 

 pear-shaped, with a large blind sac, two-thirds as long as the stomach. 



