421] PSEUDOPHYLLIDEA FROM FISHES—COOPER 133 



since most of the youngest strobilas were found lacking the end proglottis. 

 Constrictions at about the middle were present in many of them, as if the length 

 of segments behind that region might be thrown off as a whole. Since, however, 

 this is not a constant feature, it is considered to be due rather to the fixation of 

 a wave of contraction passing over the strobila, such as may be seen in living 

 individuals as well as in plerocercoids of other genera of cestodes, e.g., 

 Scolex polymorphus. 



From the foregoing description it is to be seen that this species of cestode is 

 new. The specific name, here chosen, has reference to the peculiar shape of 

 the scolex as seen from the side: cuspis, an arrow-head. 



The material studied consisted of Nos. N.B. 6a, N.B. 6d, N.B. 6g, No. 47, 

 No. 50a, No. 54c and P.B. 2 from Stizostedion vitreum, N.B. 38a, 08107, 08108, 

 08109 and 08110 from Stizostedion canadense, and Ha 34a and Ha 35a from 

 Hiodon tergisus, in the collection of the University of Illinois; Nos. 398, 423 

 and 481 from S. vitreum in the collection of Dr. H. J. Van Cleave; Nos. 7b from 

 Fercina caprodes and 421 from a "Pickerel" in the collection of Dr. G. R. 

 LaRue; twelve toto preparations from Perca flavescens in Dr. A. S. Pearse's 

 collection; and Nos. 41, 170, 172, 173, 174, 193 and 194 from S. vitreum in the 

 writer's collection. The material from Perca flavescens was larval, while that 

 from Percina caprodes was mature but of a small size. 



BOTHRIOCEPHALUS MANUBRIFORMIS (Linton 1889) 

 [Figs. 26, 27, 62, 73, 87, 88, 97] 



1889 Dibothrium manubriforme 



1890 Dibothrium manubriforme 

 1898 Dibothrium laciniatum 



1898 Dibothrium manubriforme 



1899 Bothriocephalus laciniatus 



1900 Bothriocephalus manubriformis 



1901 Dibrothrium lacinlatutn 



1901 Bothriocephalus histiophorus 



1902 Bothriocephalus manubriformis 



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

 to 220mm. in length by 5mm. in maximum breadth. Scolex large, elongate, 

 with prominent terminal disc deeply notched laterally as well as surficially, 

 constricted posteriorly; length 2 to 3.5mm., depth at middle, 1.0, breadth of 

 disc, 1.0. Bothria long and very narrow posteriorly where the walls are quite 

 thick. First segments cuneate with salient posterior borders which are dis- 

 tinctly emarginate; middle, broadly cuneate, less emarginate; posterior or 

 mature, many times broader than long and closely crowded, 5 by 0.2mm.; 

 gravid proglottides, 2 by 0.4mm. Posterior half to two-thirds of the strobila 

 provided with a median line (the combined uterus-sacs). 



Cuticula 4.5/x thick. Calcareous bodies large, 18 to 26 by 11 to 15m. 

 Longitudinal muscles well developed, in bundles. Anteriorly four chief ex- 

 cretory vessels. 



