858 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [140] 



show the worms attached, is shown in Fig. 1, Plate xv. The bodies of 

 the living worms were very much crumpled and folded and the heads 

 and anterior segments were buried in the walls of the pylorus. On this 

 account they were very difficult to remove. Usually the scolices were 

 buried together in groups of from three to six or more in a common 

 cavity. These cavities or pits extended through the mucous and sub- 

 mucous coats into the muscular layers. The heads of many of the 

 specimens were yellowish green, and nearly all were characterized by 

 having a greenish baud at the base of the neck or a greenish tubular 

 neck. 



In iny former description I recognized three distinct varieties. In 

 this lot the same varieties can be distinguished with, perhaps, a greater 

 tendency to intermediate forms. A living specimen, with mature seg- 

 ments and measuring only 32 mm length, agrees in all essentials with 

 var. a. Two others, which were quite long and slender, measuring 

 280 and 330 mm , respectively, answer, in the main, to the conditions 

 established for var. p. 



In general the specimens were not much changed by immersion in 

 alcohol, hence the measurements already published for this species need 

 not be added to in these notes. 



An interesting abnormal form was found in this lot. It consisted of 

 two slender but distinct strobiles with a single scolex. The strobiles 

 measured 25 and 65 mm , respectively. This does not seem to be a mu- 

 tilated specimen, since the two strobiles are distinct as they emerge from 

 the cervical collar. The segments do not begin at once, and when they 

 do they make their appearance at different distances from the head. The 

 segments on the latter half of the longer chain agree in outline with 

 those of var. ft. The cirrus is quite distinct and emerges near the middle 

 of a margin, or a little in front of the middle and runs thence diagonally 

 to the anterior edge at the median line. There is no sign of lateral 

 apertures. The posterior segment is 0.76 miu long and 0.66 mm broad. 



In this species, in general, the cirrus emerges near the margin not 

 far from the anterior edge of the segment. The only exception that I 

 have noticed is in the case of some individuals of variety /?, where the 

 cirrus emerges not far from the middle of a margin. In all cases, J 

 however, the cirrus and its bulb extend from the marginal opening 

 inward and forward until its base reaches almost to the anterior edge of 



o 



the segment at the median line. The cirrus is slender, smooth, and 

 tapering. 



Anatomy of scolex. I have not yet made a careful histological study 

 of this species, but in endeavoring to settle some points in the anatomy 

 of the mature segments I found it necessary to make thin sections of a 

 few segments, and at the same time stained a scolex with carmine and 

 cut it into transverse sections. 



The muscular walls of the contractile bulbs are of surprising thick- 

 ness. The bulbs lie close together, the limiting membrane of one fusing s 



