441] PSEUDOPHYLLIDEA FROM FISHES— COOPER 153 



0.35 deep in proglottides where the whole median portion is gorged with eggs. 

 In the widest segments, however, they may attain a width of 0.65mm. by a 

 length of 0.25 but at the same time not encroach so much on the neighboring 

 segments as in the last species; for the length of the broadest segments, as 

 given above, is 0.25mm. The lower portion of the sac is not modified into a 

 funnel-shaped structure, while the actual opening is only about 15ju in diameter. 



The measurements of the eggs are, according to Linton, 72 to 76ju in length 

 by 38 to 41 in breadth. Such were found in the sections made, but no opercula 

 such as shown in his figure 1 1 ; altho many similar appearances were considered 

 to be only regular breaks in the shell. 



From the above description it is to be seen that in many respects this 

 species is very close to B. manubriformis. But in others it is sufficiently 

 different to warrant the retention of Linton's designation, the more so in view 

 of the fact that the host was taken from the Pacific coast, the bothriocephalid 

 fauna of which has apparently not yet been touched. 



CLESTOBOTHRIUM Liihe 1899 



Scolex almost spherical, the free edges of the dorsoventrally situated 

 bothria fused with each other in their whole extent in such a manner that only 

 a small surficial opening near the apex leads into the interior of the spacious, 

 hollow organ of attachment, flattened in the sagittal direction, by means of 

 a short almost sagitally coursing canal which can be closed by a sphincter-like 

 musculature. External segmentation complete. Vitelline follicles in the 

 cortical parenchyma. Receptaculum seminis small. Beginning of the uterus 

 a winding canal which leads into an extraordinarily spacious uterus-sac, dis- 

 torting all other genital organs in ripe proglottides. Uterine opening about 

 median as is the dorsal genital opening. 



Type and only species: C. crassiceps (Rudolphi). 



