158 A LIST OF THE PARASITIC COPEPODA 



the last, but the furcula is distinctly and markedly difterent, the 

 branches being short, and each branch bifurcating. The male agrees 

 with the description given by Baird of a specimen which I believe 

 he mistook for a female. As this specimen was also taken from the 

 brill, it is likely that they are one and the same species. I have 

 therefore named my specimen accordingly. 



h. Abdomen short. 



5. Lepeophtheirus 2Jecioralis, Muller. This species was very common, 

 taken all round the year, from plaice, flounder, and dab ; very fre- 

 quently attached to the posterior surface of the pectoral fin, but they 

 were often seen moving actively about over the body of newly-caught 

 fish. Especially common on the flounder. Both sexes abundant. 



Elytrophora, Gerstcecker. 



(1) All four pair of legs two-branched, the terminal branch of all 

 provided with long plumose hairs. (2) The number of joints in each 

 branch varying. (3) The outer and inner branch of first pair two- 

 jointed, both branches of second and third with three joints, the inner 

 branch of fourth with two only. 



Elytrophora hrachyptera, Gerstcecker. From the gills of a large 

 tunny, Tliynnus thynnus, taken outside Plymouth, I obtained ten 

 specimens of this species, five of each sex, all alive. These I watched 

 for several hours in a bell-glass. They were very active, and the males 

 were seen to attach themselves to the females in the position repre- 

 sented in Dr. Heller's work, firmly fixed by the hook-like posterior 

 antennae, and second maxillipedes. 



Trebius, Kroyer. 



(1) All four pairs of legs two branched, the terminal joints of all 

 provided with long plumose setae ; (2) the outer and inner branch of 

 the first pair with two joints, both branches of second, third, and fourth 

 with three joints. 



Trebivs caudatus, Kroyer. Specimens were found on the dorsal 

 surface of the head, and in the nasal cavities of the skate, Baja batis, 

 but were not common. One was also taken from the skin of a pollack, 

 but possibly may have found its way there during the manipulation of 

 the fish in the boats or on the quay. 



Cecrops, Leach. 



(1) The end joints of the bifid branches of all the true legs, with 

 short hook-like bristles, or having smooth edges ; (2) front edge of 

 the cephalothorax deeply cut, two lobed ; (3) anterior antennte covered. 



