new Parasitic Copepods on Fish. 15 



both sexes were found, the pigmv male being single, attached 

 usually to the genital sesraent under the arms of attachment 

 tPLYI.fig. 1). 



Female. — Cephalothorax in the same straight line as the 

 body, rounded anteriorly, somewhat dilate:!. Sicond maxilli- 

 peds equalling in length the cephalothorax, directed down- 

 wards and forwards, widely separated from base to extremity, 

 where they unite and give rise to a well-marked stalked disk 

 of attachment ; on the under surface of each arm is a process 

 giving off four elegant elongated filaments. Body (genital 

 segment) oval, constricted in front; from the posterior extre- 

 mity on either side is a prolonged bifid appeniage; centrally 

 two small caudal lanceolate plates are present. 



Length 6 mi Him. 



Male (PL VI. fig. 3). — About 1 millim. long. Cephalo- 

 thorax distinct from the body, which is long and indistinctly 

 segmented, terminating in two short caudal processes. 

 Anterior portion of the cephalothorax carrying the mouth- 

 organs and antennae. Anterior anfennce tliree-jointed, with 

 three fine bristles at the end of the last joint. Poste- 

 rior antenncE terminating in a thickened joint with a short 

 tubercle on outer side, and the inner with a small recurved 

 hook. Mandible long, with bifid end ; extremity of mouth 

 finely ciliated. Both pair of maxillipeds large ; the first 

 provided with a very strong hook, the second with a much 

 smaller one. 



1 have not either the plate or description of " Steenstrup 

 and Liitken " to refer to with regard to their B. appendicu- 

 laia, and have therefore provisionally called this species as 

 above. 



EXPLAXATIOX OF THE PLATES. 

 Plate I. 



Fir/. 1. Bomolochus triceros, 2 , sp- Q-? from back, magnified. 



1 a. From underside, more enlarged. 1 b. Hamulus. 1 c. Pos- 



terior antennse. 1 d. First perfeopod. 1 e,f, y. Tbird, 

 fomth, and fifth peraeopods. 

 Fiff. 2. Bomolochus tetradonis, sp. n., 2 > from back, enlarged. 



2 a. Antennae vrith. mouth-organs, seen from beneath, much 



enlarged. 2 b. Terminal joint of posterior antenna;. 

 2c. Extremity of second maxilliped. 2d, e,/, ff. Second, 

 third, fourth, and fifth perteopods. 2 h. Caudal plate. 



Plate H. 



Fi(/. 1. Caligus parvus, $, sp. n., enlarged. 



la. Under surface of cephalothorax. \b. Last joint of fii-st 

 perseopod. 1 c, d. Second and third peraeopods. 1 e. Caudal 

 plate. 



