640 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 40. 



Female reproductive organs. — Vagina (figs. 5, 6, vag.) opens into the 

 bottom of the genital cloaca ventral and posterior of the cirrus pouch, 

 passing in a nearly straight course on the ventral side of the ventral 

 longitudinal excretory vessel and on the posterior side of the mass 

 of coils of the vas deferens. Near its inner end, the vagina is enlarged 

 to form the seminal receptacle (fig. 5, sem. rec), oval in shape, situated 

 originally on the median side of the mass of coils of the vas deferens, 



about midway between the dorsal 

 and ventral surfaces of the seg- 

 ment. At the height of its de- 

 velopment the seminal receptacle 

 measures 125 \i or more in length. 

 In gravid segments it is pushed 

 dorsalward by the uterus against 

 the ventral surface of the dorsal 

 layer of transverse muscles. 

 Mediad from the seminal recep- 

 tacle the vagina is prolonged for 

 a distance of 40 or 50 fi, and at 

 its termination joints the oviduct. 

 The ovary (fig. 5, ov.) is located 

 ventrally in the medullary portion 

 of the segment on the median 

 side of the coils of the vas defer- 

 ens, and extends a variable dis- 

 tance toward or beyond the me- 

 dian line of the segment. The 

 oviduct passes from the ovary in 

 a diagonal direction laterally (i. e., 

 toward the pore side of the seg- 

 ment) and dorsally and after join- 

 ing the inner end of the vagina, 

 continues in an inward (i. e. toward 

 the median line of the segment) 

 and dorsal direction. Curving 

 around the ventral surface of the 

 shell gland (fig. 5, s. g.) it enters the 

 The shell gland measures about 150 p 



I mm. 



FlG. 4.— SPnYRONCOT^NIA UNC'NATA. Gravid seg- 

 ments from POSTERIOR PORTION OF STROBILA. ex., 

 EXCRETORY VESSEL; g. p., GENITAL PORE; par. Ut., 

 PARA-UTERINE ORGAN; Ut., UTERUS. ENLARGED. 



latter on its median side, 

 in diameter and is situated in the dorsal portion of the medullary 

 parenchyma, near the seminal receptacle, dorsal of the latter 

 and nearer the median line of the segment. Shortly before or 

 after entering the shell gland the oviduct is joined by the yolk 

 duct. After passing through the shell gland" the oviduct runs in the 

 ventral direction and presumably joins the uterus. The yolk gland 

 (fig. 5, y. g.) is a rounded body about 100 /x in diameter situated in 



