1917. J NATURAL SCIENCES OF PHILADELPHIA. 141 



The kidney (PI. XIII, fig. 13) lies on the dorsal side of the body, 

 immediately above the anterior half of the hermaphroditic gland. 

 In two specimens it was relatively thin and sheetlike, while in half 

 a dozen other cases it occupied practically all of the space between 

 the ovotestis and the body wall. As may be seen in fig. 13, the 

 most con.spicuous feature of the excretory system is a long and 

 slender, thin-w^alled reservoir, somewhat crescent-shaped in lateral 

 view. The form, however, is more or less irregular, owing to great 

 numbers of diverticula springing from its surface. Each diverticu- 

 lum divides several times, the number of divisions corresponding 

 roughly to its diameter, until it finally breaks up into a number of 

 thin-walled, transparent, blind-ended tubes [comprising the major 

 portion of the kidney. 



From the central and most elevated portion of the main reservoir 

 a wide cylindrical duct arises, which, narrowdng as it pursues a 

 course dorsall}^, opens upon the surface of the body on the left side 

 of the anal opening. For a portion of the distance this canal is in 

 contact with the rectum, and the excretory and anal openings are 

 accordingly very close together. As indicated by the drawing 

 (fig. 13), the ureter bears several excretory diverticula, and becomes 

 muscular and non-glandular only in the neighborhood of the external 

 opening. The reno-pericardial canal likewise is borne on the dorsally 

 directed ureter in the form of a short, inconspicuous tube, terminating 

 in much folded, ciliated nephrostome. 



The reproductive system forms a conspicuous and compact mass 

 in the posterior half of the body (PI. XII, figs. 6, 8, 9). Of the 

 various component elements, the gonad, occupying the posterior 

 half of the visceral cavity, is the largest and presents the appearance 

 of a slender conical organ comprising vast numbers of lobules. In 

 section each of these is seen to be composed of several short acini 

 communicating near the excurrent duct with a common chamber. 

 Spermatozoa are developed in the more central acini, while those 

 more externally placed contain ova only. 



From each lobule of the gonad a slender duct arises, unites with a 

 corresponding duct from some other lobule, and these unite with 

 other and larger tubes, until finally the resulting main duct, the 

 hermaphroditic canal, is formed that courses along the entire ventral 

 face of the gonad. At the anterior border of the gonad it expands 

 perceptibly, and in the form of a yellowish, smooth-walled structure 

 undergoes a few twists, and upon decreasing its diameter divides into 

 two branches, the oviduct and vas deferens, respectively. 



