Subfamilies, Genera, and Subgenera — Recent and Fossil 53 



part of the vas deferens shows the sperm canal to be located in the center 

 and to have a central exit (fig. 5). The absence of a distinct muscular 

 ring or diajihragm is noteworthy. 



Female Organs. The sperraatheca (S) in the specimens examined is 

 about 1.5 mm. long and 1 mm. wide, globular or pear-shaped, and attached 

 to the uterus by a short, narrow duct about 1 mm. long (SD). The vagina 

 (VG) is very short (less than 0.5 mm.) and wide. The uterus (U) is as 

 wide as the vagina and is about 5 mm. long. The nidamental gland (NG) 

 is as long as the uterus and surrounds a large part of the oviduct (see 

 fig. 1). It is greatly lobulated. The free oviduct (OD) is short (about 2 

 mm.) and about as narrow as the sperm duct. Beneath the albumen gland 

 the sperm duct and the oviduct are joined to form the ovisperm duct (fig. 

 6). The albumen'gland is large (3.5 by 2 mm.) and is a mass of small sacs 

 (AL). A small duct enters the carrefour (CF) which in turn enters the 

 oviduct in front of the junction of that organ with the sperm duct. 



Hermaphrodite Organs. The ovotestis (OT) consists of many club- 

 shaped diverticula placed in a double row (fig. 8). The ovotestis is buried 

 in the cell-mass of the liver (fig. 9). The ovisperm duct (SO) is divided 

 into two external parts separated by the seminal vesicle, through which it 

 passes. One portion, about 5 mm. long, extends back of the sperm duct at 

 its junction with the oviduct and gradually enlarges as it enters the 

 seminal vesicle. A smaller tube, about 3 mm. in length, passes from 

 the seminal vesicle to the ovotestis. 



The genitalia of Planorbis planorbis have been figured by several 

 European conchologists. Germain's figure (1931, p. 523, fig. 533) is in 

 general like the figures in this work, but there is lack of detail. The 

 spermatheca is shown in a more elongated form, but this organ is subject to 

 more or less variation. The large seminal vesicle is indicated by a swelling 

 in the ovisperm duct. L. Soos's figure (1917, p. 41) agrees in general with 

 that shown in this work. The prostate shows relatively the same number of 

 diverticula. The spermatheca is shown on a long duct and the spermatheca 

 is pear-shaped, not rounded as was observed in all specimens personally 

 examined. Germain's figure is like Soos's in this respect. There appears to 

 be some variation in this organ perhaps due to seasonal or sex condition. 



The penial complex in Soos's figure is not shown in sufficient detail, but 

 the position of the retractor muscle indicates a short vergic sac. The 

 seminal vesicle shows an enlargement. A. Soos's figure (1935, p. 25) appears 

 more nearly correct, showing for the first time the separate prostate duct. 

 The spermatheca, however, is shown of a pyriform shape and on a long 

 duct. The figure of the related species carinatus JMiiller (p. 24) given by 

 Soos is more like the Poland specimens of planorbis personally examined. 

 The duct of the prostate is shown as very short while in the Poland ma- 

 terial the free portion of this duct is much longer before entering the vas 

 deferens. The lower portion of the female complex is shown very much 

 longer in Soos's figure than was observed in the Poland specimens. 



Respiratory and Renal Systems. The pseudobranch (P, fig. 3) is leaf- 

 shaped, flattened, about 2.5 mm. long and 2 mm. wide. The rectum (R) 

 pierces it after bordering the columella muscle and the anus has its exit at 

 the lower edge (A). The respiratory tube or pncumostome (PS) forms a 



