353] 



PSEUDOPHYLLIDEA FROM FISHES— COOPER 



65 



following table gives measurements of the three largest specimens of the ma- 

 terial studied : 



Length 



Length of scolex 



Length of bothria 



Breadth of scolex 



Depth of scolex 



Width of strobila just behind scolex 



Maximum breadth 



Average breadth 



Depth at middle 



21mm. 

 0.37 

 0.66 

 0.72 

 1.02 

 0.74 

 1.60 

 1.2 

 0.61 



The cuticula is about 5/x in thickness not only over the general surface of 

 the strobila but also in the interior of the bothria. In the latter situation it 

 is divided into two layers comparable to those described by Schneider (1902a: 

 75) for B. nylandicus: an outer, occupying about three-fifths of the whole 

 thickness and made up of comparatively long comidia or pseudocilia, and 

 an inner, quite darkly staining stratum. Whereas Schneider stated that 

 "Diese Harchen finden sich iiberall auf der ganzen Oberflache des Cestoden 

 mit alleiniger Ausnahme der beiden Hohlraume in den Saugnapfen und der 

 Rinne, welche den Scolex vom Rumpfe scheidet, " the writer found that these 

 were the very places the two chief layers were best seen. 



The musculature is quite similar to that of B. nylandicus as described by 

 Schneider. All of the series are about equally, but none strongly, developed 

 and each consists of isolated fibres. The arrangement of the fibres in the 

 scolex is quite like that of Clestobothrium crassiceps, there being, however, no 

 sphincters controlling the openings of the bothria. 



The main longitudinal nerves are situated in the median frontal plane and 

 about two-ninths of the transverse diameter of the strobila from the margins, 

 posteriorly as well as in the neck region. In transverse sections each strand 

 varies considerably in size and shape, but it is constantly considerably com- 

 pressed and has a transverse diameter of from 15 to 20)Lt. Anteriorly the system 

 differs greatly from that of B. nylandicus. In the latter, according to Schnei- 

 der, the chief strands bend outwardly at enlargements in the region between the 

 scolex and body ; and from each of these nerves are given off to the neighboring 

 bothria and one main branch towards the tip of the region to unite with its 

 fellow of the opposite side, thus forming a commissure which is bowed forward. 

 In this species each main trunk divides from 0.25 to 0.40mm. behind the poster- 

 ior borders of the bothria into two branches of equal size which continue for- 

 ward in a strictly sagittal plane as they gradually enlarge. At about the mid- 

 dle of the bothria each of these four trunks gives off large branches to the 

 lateral walls of the former, and then, while approaching the median line and 

 partly fusing with its fellow of the opposite surface, sends off several small 

 branches to those on the other side. The commissure is, therefore, not single 

 but composed of a number of transverse connectives of varying size. The 



