130 BRITISH PARASITIC COPEPODA. 



and armature. Caudal rami moderately stout, fully as 

 long as the last abdominal segment ; two short spines 

 springing from the outer margin of each ramus and 

 three from the apex, the middle seta being the longest. 

 Length about 2 mm. Colour similar to that of the 

 gills of the fish. 



No males have been met with. 



Habitat. — Parasitic on the gills of the piked dog- 

 fish or spur-dog, Squalus acanthias Linn.( = Acanthias 

 vulgaris Bisso). Beaumaris Bay, Anglesey, Septem- 

 ber 1901, and other parts of the Irish Sea (A. Scott). 



This Eudactylina is frequent on the gills of Squalus acan- 

 thias captured in the Irish Sea, and it may probably also occur 

 on Scottish specimens of the same fish. Eudactylina acuta 

 has been recorded from both the angel-fish and the piked 

 dog-fish by van Beneden and Dr. Canu, but though the 

 Eudactylinse obtained by these authors from the two fishes 

 mentioned may belong to the one species, those found para- 

 sitic on the dog-fishes taken in Beaumaris Bay, &c, certainly 

 differed from the specimens obtained on angel-fishes captured 

 on the English and Scottish coasts and examined by us. 



3. Eudactylina similis T. Scott. 

 (Plate XXXVII, figs. 4, 5; Plate XXXIX, figs. 1-17.) 



1902. Eudactylina similis T. Scott. (114) p. 295, pi. xii, figs. 1-19. 



Female. — First cephalothoracic segment about one 

 and a half times as long as the next, but the length of 

 that segment, and of the two that follow, nearly the 

 same ; the last segment rather smaller than any of the 

 others. Abdomen, including the genital segment, 

 short, being only about one-third as long as the 

 cephalothorax. 



Antennules stout, and somewhat similar in structure 

 and armature to those of Eudactylina acuta, but the two 

 principal spines have each a fringe of minute prickles 

 along the upper edge, and the penultimate joint is 

 proportionally shorter ; antennse tolerably stout, elon- 

 gated, and composed of four articulations, the first 

 and second joints each provided with a stout but 



