[21] 



ENTOZOA OF MARINE FISHES OF NEW ENGLAND. 



473 



found protruding as much as 0.5 m,n . It is covered with minute spines 

 whose length is about one eighth the breadth of the penis. The vas 

 deferens is a long convoluted tube lying for the most part a little in 

 front of the center of the proglottis. The central part of the proglottis 

 around the ova is filled with the large glandular masses of the testes. 

 The longitudinal vessels of the water-vascular system can usually be 

 distinguished and between them and the margin, on each side, a series 

 of granular masses, more opaque and smaller than the masses which 

 make up the testes, extending to the ovary and widening in the vicinity 

 of that organ. The lateral aperature for the discharge of eggs is sit- 

 uated a little way back of the middle and is surrounded by a low bor- 

 der or lip. It is oval in outline, the longer axis coinciding with the 

 longitudinal axis of the segment and equal to about one-eighth the 

 length of the segment. Its posterior edge is at about the posterior 

 third of the segment and nearly opposite the marginal opening of the 

 generative organs. 



The following measuremeuts were made upon living specimens which 

 had lain for a few hours in fresh water : 



Dimensions. 



Length of strnliile 



Breadth of head 



Length of bead 



Breadth of segments near head, excluding projecting flaps 



Length of segments near head 



Breadth of posterior segments 



Length of posterior segments 



No. 1. 



iinn. 

 100. 00 

 1.7 

 1.4 

 0.0 

 0.7 

 1.7 

 1.2 



No. 2. 



mm. 



142. 00 

 1.90 

 1.50 

 0.56 

 0.35 

 1.26 

 1. 26 



No. 3. 



mm. 



195.00 



1.80 



1.45 

 0.70 

 0.50 

 1.90 

 1. tit) 



No. 4. 



in in. 



212.00 

 1.8 

 1.5 

 0.7 

 0.7 

 1.8 

 1.4 



The following measurements are from a segment which became de- 

 tached from a strobile while still living and active in sea-water : 



Millimeters. 



Length 3.10 



Breadth in front i 05 



Breadth , middle 2.45 



Breadth, posterior end o. 10 



Length of penis 0. 35 



Breadth of penis , 0. 0875 



Length of spines on penis 0. 0100 



Diameter of ova 0. 0254 



The breadth given above is approximate, as the segment was con- 

 stantly changing its shape; the penis was only partly everted. 



The following measurements are from a young specimen, in fresh 

 water : 



Millimeters. 

 Entire length 20. 00 



Length of head 120 



Breadth of head 1_ y0 



Length of anterior segments 0. 10 



Breadth of anterior segments 0. 30 



Length of median segments 0. 07 



Breadth of median segments 0. 90 



Posterior segments hut little larger than anterior. 



