56 BRITISH PARASITIC COPEPODA. 



New Quay Head on 16th June 1906; also on speci- 

 mens of the same fish captured off Puffin Island in 

 1908 ; on Zeus faber taken in Luce Bay, September 

 1911 (A. Scott). 



This species may be distinguished from those closely allied 

 to it by the unusual length of the second joint of the anten- 

 nules, by the form of the sternal fork, and by the structure 

 and armature of the fourth pair of thoracic legs. 



8. Caligus brevicaudatus A. Scott. 



(Plate VI, fig. 3 ; Plate VIII, figs. 10, 11 ; Plate 

 XLVIII, fig. 6.) 



1901. Caligus brevicaudatus A. Scott. (107) p. 349, pi. ii, figs. 7-10. 



Female. — Carapace suborbicular, rather wider pos- 

 teriorly than in front, and equal to fully half of the 

 entire length of the animal. Frontal plates large and 

 slightly arcuate ; lunulas prominent. Free thoracic 

 segment short and narrow. Genital segment oblong in 

 outline, rather longer than broad, and equal to about 

 half the width of the carapace. Abdomen very short 

 and uniarticulate. Caudal rami also very short, and 

 furnished with a few plumose seta?. 



Antennules moderately stout, end joint rather shorter 

 than the basal one. Sternal fork moderately stout, 

 and with the rami also stout and scarcely divergent, 

 and rounded at the tips. Second maxillipeds tolerably 

 elongated, and slender, with somewhat feeble terminal 

 claws. Fourth pair of thoracic legs small, and com- 

 posed of three joints ; basal joint tolerably stout, ramus 

 slender and rather longer than the basal joint; the 

 terminal joint also rather longer than the preceding 

 one ; a small spiniform seta springing from the 

 extremity of the basal joint on its upper aspect, and 

 the first joint of the ramus provided with a similar 

 seta on its outer distal angle ; the end joint with three 

 apical setge which differ considerably in length, the 

 inner one being about as long as the joint from which 

 it springs, the outer scarcely half as long, the middle 



