neic Farasi'tic Copepods on Fish, 3 



the gill-cavities of Stromateus cinereus (white pomfret), both 

 male and female : it differs essentially from B. megaceros of 

 Heller, which he found on Stromateus niger^ on which fish I 

 frequently also found that species ; it, however, bears out- 

 wardly a nearer resemblance to B. scomberesoces of Kroyer, 

 but differs from the latter in detail, the three setaceous horns 

 being much more pronounced, the last joint of the fifth perseo- 

 poda having four instead of three short setae, &c. (see PI. I. 

 fig. 1). 



Female. — Body elongate ; cephalothorax 5-partite, first seg- 

 ment much broader than long. Frontal border deeply concave 

 in the middle line. Anterior antennce elongate, basal joint 

 arcuate ; at the inner end there is placed a trilobate process, 

 the root of which connects with a curious circular disk, the 

 anterior margin of which is fringed with fine hairs ; from 

 each lobe of tliis frontal appendage springs a strong simple 

 sharp bristle, the inner being slightly tlie longest ; there are 

 also three more simple bristles from the anterior frontal border, 

 the one immediately outside the frontal process being long 

 and very slender, the other two much shorter. The whole 

 anterior border is fringed with about twelve finely plumose 

 set£e, two being inside the frontal process, tiiree between first 

 and second bristles, and two between second and third ; tliere 

 are four elongated free joints provided with fine hairs at the 

 angles, the last with seven at the extremity. Posterior an- 

 tennce biarticulate, second joints minutely granular, terminating 

 in a thickened crenulate pointed process, and four tine simple 

 seta^, the inner border finely dentate, the teeth becoming- 

 much coarser near the end and elevated. Hamulus placed 

 laterally ; it is large and two-jointed, the second joint made up 

 of an elongated hook with a ciliated appendage of equal length. 

 Rostrum very long and pointed. First perceopods two- 

 branched, outer with one joint, the inner with two, all provided 

 with plumose hairs ; second, third, and fourth two-branched, 

 each with three joints, the outer branches carrying on the 

 outer side short spur-like bristles, the others plumose; fifth 

 single-branched, the last joint being provided with three 

 short bristles terminally and one on the outer border. Genital 

 segment square. Abdomen of four joints, decreasing in size 

 downwards, the last bearing the caudal plates^ which are 

 longer than broad, giving off one very strong central bristle 

 and two short fine lateral ones ; also a minute hair is seen on 

 the outer border. 



Egg-sacs large, dilated. 



Male smaller, but differing slightly from the female. 



1* 



