798 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [80] 



that they could be counted. I continued this work as long as my 

 patience and the time at my disposal lasted. Upon counting the speci- 

 mens-that I had thus separated I found that there were one thousand 

 nine hundred and sixty-three. In numbering the specimens I counted 

 only the scolices. As the number was so near two thousand I re- 

 turned to the work of assorting, and in a few minutes added fifty more 

 scolices to the above number. One may therefore be very safe in say- 

 ing that there were over two thousand individuals of this species in 

 the spiral valve of this dusky shark. There yet remain several hundred 

 specimens in the unassorted lot. The specimens of this lot vary in size 

 from 5 to 30 mm . The short specimens are doubtless in most cases frag- 

 men ts of longer strobiles. The alcoholic specimens show a great variety 

 of size and proportions, due to different stages of contraction. Some 

 are slender and filiform, others so thick' as to be almost wedge-shape. 

 Between these two extremes there are a great variety of gradations. 



Two distinct kinds were recognized among the living specimens. 

 One very slender, transparent, bluish white ; the other stouter, shorter, 

 opaque, and ivory white. These differences are plainly due to different 

 states of contraction. One of the former had the following dimensions 

 while living: Length, 27 mm ; breadth of neck near head, .l ram ; seg- 

 ments begin about 6 mm back of the head; length of posterior segment, 

 3.2 mm ; breadth, .32 mm . 



The bothria, while quite active during life, do not exhibit a very 

 great diversity of outline. Their anterior ends frequently elongate and 

 curve outward and back in horn-like prolongations. An opposite move- 

 ment is that in which the anterior ends of the bothria are closely ap- 

 pressed and the broadly rounded posterior ends are curved outward 

 and forward. These movements give to the head quite diverse out- 

 lines, but with all the flexibility of the bothria they were not observed 

 to exhibit any tendency to crumple or become folded on the margins. 

 In the alcoholic specimens, however, there is a tendency in the edges 

 of the bothria to become more or less irregular in outline. Some of 

 the specimens have the edges of the bothria slightly folded. There 

 are no loculi along the border. 



This cestod can be very easily recognized by the fine transverse fur- 

 rows and ridges which give the margins of neck and segments a serrate 

 outline. These can be seen with low magnifying powers. In some of 

 the alcoholic specimens this feature is somewhat indistinct, as if the 

 epidermal tissue had become loosened by the preserving fluid. 



None of the posterior segments contained ova. The ovaries are rather 

 small, paired organs at the posterior end of the segment. The-vagina, 

 originating between the ovaries as a convoluted tube, can be traced 

 along the median line to the cirrus bulb, around which it bends like the 

 handle of a shepherd's crook, to open beside and in front of the cirrus 

 in a genital cloaca common to both vagina aud cirrus. The latter is 

 Jong and slender. It was retracted in every case, and its exact length 



