482 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [30] 



Generative organs : male not conspicuous, smooth, marginal, near 

 anterior edge of proglottis as in all; female lateral, median, dehiscent, 

 in mature proglottides easily recognized as a clear central spot ; length 

 of strobile as short as 3G mm ; average, perhaps, about 45 mm , although it 

 seems to graduate into var. ft, which is much longer. In one specimen 

 measuring 4S mm , the last twelve proglottides were mature and had an 

 average length of l mm . 



Measurements of a specimen, var. a, made from a mounted specimen, 

 and hence probably a little distorted : 



Millimeters. 



Length of strobile 36.00 



Length of bothria 0. 80 



Breadth of head 0.90 



Length of neck 0. 70 



Breadth of neck in front 0.G0 



Breadth of neck, posterior end 0. 36 



Length of proboscis 0.70 



Length of proboscis sheath 0. 76 



Length of contractile bulb 0. 32 



Breadth of contractile bulb 0. 14 



Length of posterior proglottis 0. 80 



Breadth of posterior proglottis 1.30 



The second group I shall also, for convenience, designate as a variety, 

 calling it var. ft (Plate IV, Figs. 17-20). The strobile, like that of var. 

 <*, is flat and thin, but is much longer. The mature proglottides do not 

 make their appearance until 100 mm , or even 200 mm , back of tbe head. 

 The first segments are short and broad; the succeeding segments in- 

 crease in length until they become longer than broad. The median and 

 postero-median segments are frequently rounded at the corners, giving 

 to the strobile a beaded appearance. This character is usually present 

 in those segments which immediately precede the mature proglottides. 

 Usually about three longitudinal strise can be traced on the median seg- 

 ments (Figs. 18-19). The posterior segments are rectangular, longer 

 than broad. The following measurements were made on a mounted 

 specimen, var. ft. 



Millimeters. 



Length of strobile 230.00 



Length of head 0.76 



Breadth of head 0.94 



Length of neck 0. 70 



Breadth of neck in front 0. 70 



Breadth of neck, posterior end 0. 40 



Length of proboscis 0. 60 



Length of proboscis sheath ,- 0. 64 



Length of contractile bulb . 0. 36 



Breadth of contractile bulb 0.16 



Breadth of strobile back of neck 0. 26 



Leugth of posterior proglottis 1. 54 



Breadth of posterior proglottis 1.20 



A third group, which comprises individuals that have certain charac- 

 teristics separating them from the two preceding groups, I have distin- 



