24 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[374 



Locality 



Latitude 



Number of 



Proglottid 



Number of in which Number of 



Proglottids Eggs first Testes 



in uterus 



196 (19) 75-8i (6) 68.9 (10) 



Lincoln, Springfield 



and Clinton, Illinois 40 



Minneapolis, Minnesota 45 



Brainerd, Minnesota 45 21' 



Wahpeton, North Dakota 45 21' 



Bemidji, Minnesota 47° 28' 30' 



Thief River Falls, Minnesota. 48° 7' 

 Emerson, Manitoba 49° 



In judging from these figures it must be borne in mind that while 

 Emerson, Manitoba is considerably farther north than Bemidji and 

 Brainerd, Minnesota, it is, nevertheless, in the transitional zone while 

 they are in the boreal. It will be observed from this table that while 

 there is a considerable difference between the extremes, the intergrada- 

 tions are sufficiently regular to destroy the validity of these differences 

 as specific characteristics. They are therefore here classed as one spe- 

 cies, with the specific name "variabilis". The northern forms are fur- 

 ther recognized as a variety, with the name Anoplocephala variabilis 

 "borealis. 



Anoplocephala infrequens sp. nov. 



[Figures 25 to 27] 



This cestode was found rather sparingly in Geomys bursarius in 

 northern Minnesota and* just across the Canada line, at Emerson, Mani- 

 toba. Recently also, through Professor Ward I have received from 

 Professor Young a cestode taken from Evotomys sp. at Grand Forks, 

 North Dakota, which is identical with these. In all, ten specimens were 

 secured from the gophers. All were taken from the last inch of the 

 small intestine or the adjacent part of the large intestine, were un- 

 attached, and showed no signs of life. Whether or not they belong this 

 far back cannot be said positively; but the fact that three were imma- 

 ture and that all but one were in good condition when found would 

 seem to indicate that they had not died and drifted back. The follow- 

 ing description was based upon three sectioned and three adult alcoholic 

 specimens. Later, the specimen from Evotomys was sectioned and 

 compared; no significant points of disagreement with the account here 

 presented were discovered. 



