160 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 55. 



In P. chaloneri the spermatheca includes a rather large, median 

 sac which branches at the anterior end in 13 into two extensive furcae 

 (fig. 12) and in 17 curves first laterally and dorsally and then ven- 

 trally around the bursa and then joins the ventral wall, and com- 

 municates with the exterior through the spermathecal pore at the 

 median ventral point of 18/19. The median sac lies ventrad of the 

 nerve cord and between it and the body wall. Each anterior furca 

 or branch curves dorsad and posteriad to a point about midway of 

 the length of the median sac and of the clitellum, but pushes the 

 septa back and so remains in 13, as indicated by the internal 

 metamerism. Each of the pair of oviducts has a rather direct course 

 from the oviducal pore to the enlarged " eitrichterblase " which is 

 attached to the anterior side of 13/14. One sperm-filled diverticulum 

 of the oviduct (samenkammerchen, Michaelsen) is included in the 

 thick wall of the "eitrichterblase." The remaining part of the 



oviduct, communicating with the cor- 

 responding spermathecal furca near 

 - -^.^ its base, has also a rather direct 

 - ' ^ course. 



--....43 111 Polytoreutus the characters of 

 the spermathecae are recognized as of 

 first-class importance for specific dis- 

 FiQ. 12.-POLYTOREUTU3 CHALONERI. tluctions. lu a ^Tge maiorlty of the 



Wax model reconstructed in part . '^ "L j^ -i i 



FROM SECTIONS SHOWING CERTAIN FE- 30 or morc spccics already described 

 MALE REPRODUCTIVE ORGANS. x7. od, ^^iQ spcrmathcca clthcr lacks anterior 



Oviduct; os, ovisac; st, median sper- ^ • i i 



MATHECAL sAc; st f, FURCAL BRANCH furcac or has postcrior branches or 



oT spermatheca. gjgg ^YiQ worm has paired copulatory 



organs near the male pore. Any one of these characters is sufficient 

 to distinguish its possessor from P. chaloneri. There are but four 

 species which are not in some such way distinguished from the new 

 form. These four species are P. haralypton., P. finni, P. hindei, and 

 P. Mlindinensis. 



P. haralypton Cognetti (1911) is distinguished from the new 

 form by having the male pore at 17/18 instead of anterior to the 

 middle of 17; by the absence of a muscular bursa associated with 

 the male pore; by the absence of diverticula of the prostate glands 

 at the points of entrance of the sperm ducts; and there are also 

 marked difi'erences between the two species in the number of somites 

 and in the extent of the sperm sacs as well as other minor difi'erences. 



P. ftnni Beddard (1894 and 1901a) is distinguished from the new 

 form by its much greater length and tenuity, but especially by 

 having over three times as many somites, over 500, which is a very 

 unusual number. The former species has also much more slender 

 and shorter sperm sacs than has the latter, and the male and sper- 

 mathecal pores and intervening surface of the former are much 



