383] ANOPLOCEPHALIDJE—DOUTHITT 33 



Schizotaenia variabilis sp. nov. 



[Figures 30 to 32] 



Some years ago Dr. A. K. Fisher collected cestodes from a number 

 of porcupines {Erethizon dorsatus) at Lake George, New York. These 

 in the Bureau of Animal Industry at present bear serial number 1502. 

 Stiles (1896) examined them and identified them as Bertia americana 

 (now Schizotaenia americana). Professor Ward secured the loan of 

 these specimens. Examination has shown that they do not represent 

 8. americana, but are a distinct species. The following description is 

 based upon a single complete specimen, not sectioned, and several sec- 

 tioned portions from the region of sexual maturity. The specimens 

 reported by Cohn (1906) from Erethizon epixanthus from Alaska seem 

 referable to this species rather than 8. americana, since he reports that 

 the female glands are located far from the median line. 



The complete specimen at hand, which appears to be fully grown 

 and has shed proglottids, is 20 mm. long and is composed of 60 pro- 

 glottids. The greatest width, 8.5 mm., is reached 18 cm. from the 

 head ; back of this the strobila narrows somewhat. All the proglottids 

 are very short in comparison with the width, except the last which is 

 6 mm. wide and 1.5 mm. long. The fragments at hand agree with this 

 specimen, except that some have longer and thicker proglottids the 

 width being the same ; this would seem to indicate that they came from 

 a larger specimen. Three scolices are present; they measure 450/a long 

 by 875/* wide. One is retracted within the end of the strobila as in 

 8. americana. 



The genital pores are regularly alternate. The genital cloaca and 

 cirrus pouch agree with the description just given for S. americana, 

 except that the cirrus pouch is somewhat smaller being ordinarily 485 

 to 500ju, long tho it is sometimes longer. Its width is 140 to 185/*. The 

 vesicula seminalis is of necessity much shorter than in 8. americana on 

 account of the nearness of the female glands to the lateral margin. 

 It is variable in form, being sometimes straight and sometimes in the 

 form of large, wide loops, as shown in Fig. 30. The gland-cells on the 

 inner end of the vesicula are usually more numerous than in S. ameri- 

 cana, as shown in the same figure. The vagina is identical but of 

 course shorter. 



The testes are decidedly unlike S. americana in form and distri- 

 bution. Nearly all are elongated anteroposteriorly, the breadth being 

 to the length as 5 :7. In some specimens they are 60 to 80/x long while 

 in others they are 95 to 130/a long. These measurements were all taken 

 at sexual maturity. They occur only in the median field and are 



