32 PKOCEEDINGS OF THE NATIONAL MUSEUM vol. 81 



because of a number of differences between that worm and Han- 

 num's description of P. onagnus I at first believed it to be a distinct 

 species. Later, however, I found three tapeworms in the intestine of 

 Rana clamitans^ at Houston, Tex.; and the variations exhibited by 

 these three worms are such that only one important difference re- 

 mains to be explained. Hannum states that the shell gland is repre- 

 sented by only a few unicellular glands, which are clustered about 

 the caudal portion of the ootype, while in all my material a well- 

 developed shell gland, which practically envelops the coils of the 

 oviduct, is always present. I have noticed in other closely related 

 forms, however, that the shell gland soon loses its property of retain- 

 ing stains, and therefore a portion of it may easily be overlooked 

 in a specimen that has been kept in a preservative for some time. 

 Aside from this point there is such close correspondence between 

 my material and Hannum's description that specific identity seems 

 quite certain. 



Variations in my material, which are strikingly greater than those 

 recorded in the original description, are as follows: The testes vary 

 from 98 to 190 to the segment; the main excretory ducts frequently 

 run through the middle of the testicular field ; the vagina usually 

 opens anterior to the cirrus, but it may open beside or posterior to 

 the cirrus; and the specimen from Rana catesbeiana is only 22 cm 

 long. The three specimens from Rana clamitans are each about 65 

 cm long. The genital pore is commonly farther anterior than Han- 

 num describes, frequently lying between the caudal borders of the 

 first sixth and the first fourth of the lateral margins, but occasionally 

 it is as far caudal as the union between the first and middle thirds 

 of the segment. Furthermore, in Hannum's figure the genital pore is 

 distinctly anterior to the caudal border of the first third of the 

 lateral margin. 



This marked extension of the limits of variation of P. niagmis 

 suggests the possibility that it may be synonymous with P. fllaroides 

 La Rue. When one considers the widely separated hosts, the remain- 

 ing differences appear insignificant, but I have not seen any speci- 

 mens of P. fllaroides, and therefore hesitate to draw any definite 

 conclusions. 



PROTEOCEPHALUS FARANCIAE (MacCallum, 1921) 



Plate 3, Figuee 1 



My material, which is referred to this species, consists of frag- 

 ments of a tapeworm taken from the intestine of Paranoia ahacura. 

 The snake had been run over by an automobile when found and a 

 portion of the intestine badly mutilated. Judged by the scoleces 



