Subjamilies, Genera, and Subgenera — Recent and Fossil 169 



divided into four secondary branches. In fig. 3, a single ripe ovum is shown 

 in the diverticulum. The free portion of the ovisperm duct (SO) is about 

 5 nnn. long between the seminal vesicle and the oviduct and only 1 mm. 

 long between the vesicle and the ovotestis. 



The published figures of the genitalia of Planorbarius corneus vary 

 considerably. That of Simroth (1912, tafel 26, fig. 3) is one of the best 

 and agrees with our fig. 13 on plate 20 in general gross anatomy. Lacaze- 

 Duthier's figures are also accurate as regards general anatomy and nerve 

 organization (1872, plate 20). L. Soos's figure (1917, p. 37 ( lacks detail. 

 Germain's figure of the genitalia of Planorbis corneus (1931, p. 518) lacks 

 details of structure and is less clear than that of Simroth. 



The published figures of the external and internal aspects of the penial 

 complex have been inaccurate, either in figuring or in the interpretation 

 of parts of the organs. Moquin-Tandon (1855) on his plate 32, fig. 3, shows 

 the gland of corneus which is called the penis (verge), the lower part being 

 designated as a dilation and the end of the groove is said to represent the 

 stylet. Buchner (1891, tafel 5, fig. 1, copied by Simroth, 1912, p. 502) shows 

 the penial complex incorrectly. Internally, the first type of the penis (penis 

 complex) of corneus is an error of interpretation, the penis of Buchner not 

 being the true verge but the gland appendage, which has a channel down 

 the center, thought to be the sperm canal by Buchner. F. C. Baker ( 1928, 

 I, p. 308) has copied these figures and has erroneously accei^ted the division 

 into types of the male organ in Planorbis. Other authors, as Annandale 

 (1922), have also used these penial subdivisions. Baudelot (1863, plate 4) 

 correctly figures the cylindrical appendage and gland but the appendage is 

 erroneously called the penis. Taylor (1900, p. 366) figures the terminal 

 bulbous portion, calling it the vibratile stimulating appendage, which it 

 probably is. 



The true nature of the gland and its appendage and the very small 

 true verge have not been recognized and figured until F. C. Baker's paper 

 appeared in 1931 (p. 579, plate 1). The small verge appears to be an en- 

 largement of the vas deferens and has been completely overlooked. 



Respiratory and Renal Systems. The pseudobranch (plate 20, fig. 10) 

 is an oval, elongated body extending from the anal region. It is usually 

 somewhat leaf-like but, as in the figure, it may often be folded forming a 

 rounded tube (P). The rectum (R) is large, rounded, and bears a simple, 

 rounded crest or ridge, which does not extend over the pseudobranch as in 

 Helisoma. The anal opening is above the pseudobranch (A). There is a 

 large pneumostome (PS). 



The kidney is in general like that of Helisoma corpulentum (plate 44, 

 fig. 3) except that it is longer and wider (14 mm. long and 4 mm. wide 

 at the upper part). The portion of the kidney bordering the pericardium 

 is flattened or even a trifie concave, the lower part is rounded and lobate 

 on both margins, the lobations being more numerous than in Helisoma 

 corpulentum. There is a large ridge extending down the center of the 

 kidney. A cross section of the kidney near the lower end (plate 45, fig. 18) 

 shows a rounded lumen (TK) with a vein on each side at the lower angle 

 of the lumen (RA, AP). There is a high, sharp crest or ridge (RK) causing 

 the section to be higher than wide. The ridge on the mantle, to the left in 

 the section, is wide, high, and curved (RD). 



