351] PSEUDOPHYLLIDEA FROM FISHES— COOPER 63 



As pointed out by Schneider (1902a :72) the two genera Bothrimonus and 

 Diplocotyle were separated by Liihe (1900:10) only on the basis of the differ- 

 ences in degree of fusion of the apertures of the bothria at the tip of the scolex. 

 As a matter of fact the remainders of the generic diagnoses are identical. 

 Schneider stated that the material of his B. nylandicus showed that these 

 differences were simply due to differences in degree of contraction and relaxa- 

 tion of the scolex and in particular of its termination which is the ridge separat- 

 ing the two openings of the bothria either externally or internally. With 

 considerable retraction of this ridge or septum the two openings fuse to form 

 one, while with relaxation of the same and contraction of the bothrial walls 

 the apertures are more or less separate, according to the species present. 

 While in none of the few specimens of the species described below were the 

 openings fused, various stages in the formation of a single terminal and almost 

 circular opening from the two otherwise separate openings were observed 

 in some material from Microgadus tomcod which was, however, too young to 

 be determined with certainty specifically. Consequently, it seems just with 

 the present state of our knowledge of these forms to unite the two genera, 

 Bothrimonus and Diplocotyle, and to retain the older name of Duvernoy, as 

 done by Schneider but not recognized by Linstow (1903; 1904:308). 



BOTHRIMONUS INTERMEDIUS Cooper 1917 

 [Figs. 6-8, 45, 81, 94] 

 1917 Bothrimonus intermedins Cooper 1917 : 35 



Specific diagnosis: With the characters of the genus. Small cestodes up 

 to 45mm. in length and 1.6 in breadth. Scolex almost spherical, 0.60mm. 

 long, 0.75 wide and 1 .0 thick. Bothria hemispherical, their apertures ordinarily 

 not fused to form a single terminal opening. Strobila uniform in width from 

 a short distance behind the scolex to the posterior end; 0.6mm. in thickness; 

 more convex ventrally than dorsally. 



Cuticula 5m in thickness. Nerve strands 15 to 20/i in diameter; each 

 divides into two branches sagittally before entering the scolex; transverse com- 

 missure diffuse. Four main excretory trunks in ripe proglottides, six farther 

 forward passing into the scolex; all in the medullary parenchyma. 



Reproductive organs 1.5mm. from scolex; up to 66 in number. Weak 

 sphincter around the common female cloaca. Vagina opens close behind the 

 uterine pore which is not quite in the median hne. 



Testes in two lateral fields and two layers between the excretory trunks, 

 continuous from proglottis to proglottis; spherical in shape, 80 to lOOju in 

 diameter. Coils of vas deferens anterodorsal to cirrus-sac, the duct 30/x in 

 diameter. Cirrus-sac oval, 75 by 45^ ; everted cirrus, 60 by 85/i. 



Vagina lOju in diameter; receptaculum seminis, 40 to 60^; spermiduct, lO/x. 

 Ovary crescentic in shape, wings tubulolobular; isthmus almost spherical, 

 0.1mm. in diameter. Oocapt ISfi in diameter, oviduct 15 to 20^. Common 

 vitelline duct 120 by 30^. Vitelline follicles spherical, 60// in diameter; in the 

 lateral thirds of the strobila, continuous at the margins of the same and from 



