Subfamilies, Genera, and Subgenera — Recent and Fossil 113 



penial gland duct on the outside of the i)reputiuni, emerging from the 

 latter about midway between the outlet and the summit of the preputium. 

 At the upper end of the vergic sac there are two very large fiagella (about 

 1 mm. long) which are sausage-shaped and are attached to the vergic sac 

 by a very short duct, in fact they are almost sessile. Small glands on the 

 interior of the fiagella show through as white circles, as shown in the 

 figure (fig. 11, FL). There is a wide retractor muscle which is attached to 

 the upper part of the preputium. 



Internally (fig. 8), the preputium has a large penial gland (GL) which 

 is attached to the preputium only at its base, the cup being free. It is more 

 or less circular in shape, depressed, with a wide cup-shaped depression in 

 which the walls are ridged (probably glandular). There is a short duct, 

 external to the 'preputial cavity, which enters a round, fleshy ring or 

 diajihragm between the vergic and jn-eputial cavities (fig. 8, D). The rela- 

 tionship of the gland and duct to the preputial sac is well shown in fig. 7. 

 The verge (V) is narrow, tapering, with the exit at the end in the center. 

 There is a very small papilla at one side of the opening (fig. 4). The two 

 fiagella are joined in one tube before thev enter the vergic sac (fig. 11, VS; 

 fig. 8. FL). 



Female Organs (fig. 11). The spermatheca (S) is large and almost 

 circular, and is joined to the short, wide vagina (V) by a duct which is 

 shorter than the diameter of the spermatheca. The uterus (U) is wide and 

 shorter than the spermatheca and its duct. The nidamental gland (NG) is 

 very wide, sac-like, and about twice as long as the uterus. The oviduct 

 (OD) is short and wide, about as long as the preputium. There is a large 

 carrefour (CF). The albumen gland (AL) is large, about 1 mm. long, and 

 has a space for the passage of the intestine (fig. 1) . 



Hermaphrodite Organs. The ovotestis (OT) is large with the diver- 

 ticula long and clul)-shaped. They are placed in a double series. The ovi- 

 sperm duct (OS) is very short between the seminal vesicle and the 

 ovotestis and about 1 mm. long between the seminal vesicle and the ovi- 

 duct. A spermatophore of peculiar form was found in the spermatheca 



No figure or descri]ition has been published of the genitalia of this 

 genus. Annandale says of the genitalia: 'The male organ resembles that of 

 Planorbis, except that the penial bulb is relativelv verv large' (op. cit., 

 p. 362). 



Respiratory and Renal Systems. The pseudobianch (fig. 2, P) is a 

 flatly rounded, simple lobe, pierced above by the rectum. The kidney (plate 

 47, fig. 26) is wide and fiattened and not as long as in Segmentinn or 

 Poh/pi/Us. There is no superposed ridge. In section (fig. 27) the lumen is 

 long, oval in outline with the veins about in the center on each side. 



Digestive System. The stomach is narrow as in Segmentina, the intes- 

 tine making the same loops around the stomach and liver as in the genus 

 Segmentina. The buccal sac resembles that of Segmentina. The jaw (plate 

 50. fig. 23) is fragmented as in Segmentina. There arc more than sixty 

 plates on the jaw. 



The radula has the formula 15-1-15 with over 125 rows on a liroken 

 membrane (iilate 69, fig. 9). Center tooth bicuspid, the cusps not reaching 

 the lower margin of the base of attachment. Lateral teeth (1-5) with two 



