KROYERTA LINEATA. 123 



minent in the entire animal. No trace of a fifth pair 

 of feet. 



Mule. — Length exclusive of the furcal setse 2*7 mm. 

 The cephalic segment is similar to that of the 

 female in every respect except in the shape and length 

 of the movable spines at its distal end. The spines 

 are evenly curved to the apex, and do not reach the 

 end of the first thoracic segment. The first two 

 segments of the thorax are nearly of equal size. The 

 third segment is almost twice as long as the second, 

 and its proximal lateral margins are slightly expanded. 

 The genital segment is narrow and cylindrical, and 

 distinctly longer than the combined lengths of the 

 three thoracic segments. The abdomen is composed of 

 three clearly-defined segments. The first segment is 

 about half the length of the genital segment. The 

 second and third are of nearly equal length, and are 

 each about equal to two-thirds of the length of the 

 genital segment. The furcal joints are almost similar 

 to those of the female. 



The various thoracic and other appendages are 

 similar to those of the female, and therefore need not 

 be described. A rudimentary fifth pair of feet repre- 

 sented by three minute setse can be detected by care- 

 fullv examining the lateral margins of the genital 

 segment. 



Habitat.- — In the hollows between the gill-rays of 

 male specimens of Galeorhinus galeus or tope, captured 

 in the Irish Sea in the vicinity of King William Bank, 

 off the north end of the Isle of Man, April 1912. We 

 have not yet met with this parasite on the gills of 

 female specimens of the tope, although a considerable 

 number of them have been examined. Much care is 

 required to detect the parasite, as it is usually entirely 

 hidden in the hollows between the gill-rays. The 

 presence of the parasites is occasionally revealed by 

 the egg-strings projecting beyond the ends of the 

 gills. Several specimens of both sexes may sometimes 

 be found on the gills of a single fish. 



