415] PSEUDOPHYLLIDEA FROM FISHES— COOPER 127 



syiicitial cells below, as well as of other structures lying more deeply in the 

 parenchyma. 



The parenchyma shows nothing of particular interest excepting for the com- 

 paratively large nuclei of its cells. These are on the average sUghtly larger 

 than those of the subcuticula, the largest being more constantly about 7.5^ in 

 length. No distinct traces of chalk-bodies were found in sectioned material 

 altho numerous branches of the excretory system resemble such when cut 

 transversely. 



The musculature of this species is especially well developed. The frontal 

 fibres, altho rather small, are quite numerous, considerably isolated from each 

 other, and extend from the layer of viteUine glands on one surface to that on 

 the other, everywhere interminghng with the powerful longitudinal series and 

 being discontinuous only where the largest of the reproductive organs are 

 situated. This applies, however, to mature proglottides, for in the segments 

 immediately behind the scolex they are aU but absent. In frontal series they 

 are seen to be continuous from segment to segment but naturally shghtly more 

 numerous between the sets of reproductive organs, altho they pass freely 

 among the testes. The same description appUes relatively to the sagittal 

 fibres. DorsoventraUy they intermingle with the vitelline follicles. On the 

 other hand, the longitudinal series presents quite a marked difference. As a 

 matter of fact the pronounced development of these fibres seems to be an im- 

 portant characteristic of the species. They form an area on each surface in 

 cross-section about 125/x in thickness and consequently so wide as to restrict 

 the cortical and medullary portions of the parenchyma to two narrow regions, 

 respectively about 75 and 90/1 in thickness, as shown in figure 86. The indi- 

 vidual fibres are large (as much as 6.5^ in diameter), not united into groups as in 

 B. scorpii and continuous as a whole from joint to joint. On account of their 

 great number and matted appearance in frontal or sagittal series it was found 

 impossible to determine their exact length; but it may be said that in all 

 probability they do not extend individually for more than one or at most two 

 sets of genitalia along the strobila. Only a weakly developed outer longitudinal 

 series is present, altho the foremost segments have promment posterior borders, 

 as shown in figure 24. What might at first glance be considered as such, are 

 the very large and numerous longitudmal cuticular fibres forming a compara- 

 tively wide area outside of the subcuticular nuclei in the anterior end of the 

 strobila (Fig. 69). 



As might be expected from the external appearance of the structure the 

 musculature of the scolex is well developed. Powerful sagittal and radial 

 fibres pass for a short distance behind the terminal disc, which region is there- 

 fore, as noted above, the most functional portion of the bothrium. At the 

 middle of the scolex, however, only the sagittal series is very prominent, while 

 posteriorly at the thickest part of the organ, these too disappear almost entirely. 

 The same diminution of the coronal series from in front backwarks is to be seen, 

 although they are at no level nearly so prominent as the other two sets. As in 

 the strobila the longitudinal fibres are very numerous. They pass vminter- 



