770 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [52] 



The neck is crossed with fine transverse lines which, in less than a, 

 millimeter back of the head, outline the first segments. These for a 

 short distance are very short but increase in length rapidly. In an 

 alcoholic specimen, at the distance of 1.4 mm from the head, the segments 

 are as long as broad ; at a distance of 3 mm they are a little over twice 

 as long as broad ; about the middle of the strobile their length is five 

 times their breadth ; the last segment is seven times as long as its great- 

 est breadth; the entire specimen measured 14 mm and the last segment 

 1.4 mm in length. 



The breadth of the body remains nearly uniform throughout. The 

 posterior segments are usually rather narrow at the two extremities and 

 swollen in the middle in the viciuity of the reproductive aperture. The 

 dimensions of one mature segment, somewhat flattened, are: diameter 

 near anterior end .lG mm ; diameter in front, at junction with preceding 

 segment, .l mm ; diameter at middle .22 mm ; diameter near posterior end 

 ,12mm. diameter at junction with succeeding segment .08 n,m . 



When mature segments are placed in glycerine and studied with a 

 low magnifying power, the ovaries may be seen as two long, somewhat 

 opaque bodies, lying at the posterior end of the segment, one on each 

 side of a transparent median space and extending nearly to the middle 

 of the segment. 



The reproductive aperture is marginal, about the middle of the seg- 

 ment. The cirrus was retracted in all the specimens, but it could be 

 seen, together with the vas deferens, lying in a coil in the middle of the 

 segment. Several large ova were observed lying loosely along the 

 mediau line, from the anterior end of the segment back to the front end 

 of the ovaries. These ova vary greatly in size and shape. They appear 

 to be quite large in proportion to the size of the segment, and are, 

 moreover, comparatively few. Measurements of average ova yielded 

 the following results: .017 by.011 mm ; ,019by.01 mm ; .022 by .011 mm ; 

 .017 by .013 mm . An elongated ovum measured .05 by .011 mm ; another 

 .047 by .014 mm ; a pear-shaped one was .03 mm long, .014 mm in its greatest 

 breadth, and .008 mm in its least breadth. 



The following measurements were obtained from living specimens : 



Dimensions. 



Length 



Breadth of head 



Length of hothrium 



Breadth of hothrium 



Breadth of neck 



Distance to first segment 



Length of first distinct segment 

 Breadth of first distinct segment 



Length of last segment 



Breadth of last segment 



Numhor of distinct segments ... 



No. 1. No. 2. No. 3. No. 4. 



mm. 

 7.50 



.80 



.CO 



• 10 



.09 



.40 



.05 



.10 



.20 



.20 



21 



mm. 

 13.50 



.GO 



.80 



.20 



.10 



.50 



.03 



.16 



1.04 



.24 



34 



mm. 

 1G. 00 



.80 



.24 

 .60 

 .04 

 .26 

 1.40 

 .34 

 40 



mm. 



15.00 



HO 



.10 

 .60 

 .04 

 .10 

 1.60 

 .24 

 35 



