Parasitic Cojjepoda of Fish. 13 



represented in Dr. Heller's work, firmly fixed by the hook- 

 like posterior antennas and second maxillipeds. 



On removing them the spermatophores were seen attached 

 by long tubes to the genital segments of the females. These 

 were pyriform, with a thick chitinous covering, and, when 

 broken off, thin thread-like spermatic filaments issued from 

 the tube end, or, if the capsule was broken, poured out en masse 

 (fig. 3, A and B). On the males which had not completed 

 the act the capsules were seen distinctly in the sperm-ducts, 

 but were absent from those which had been removed from 

 females bearing them, so that tiiey appear to be monogamous. 



Lernea lusci, sp. n. (PI. IV. fig. 6.) 



This animal was found only on the gills of the whiting 

 pout, Oadus luscus, and was very common, as many as four 

 beitjg found on one fish. The whole head is surrounded by 

 a clot of blood, the elongated horn being buried by the side of 

 the gill-bone. 



It is much smaller and more delicate than Lernea hran- 

 chialis ; the secondary and posterior curve of the body is much 

 less marked; there are generally three horns behind the 

 mouth, tiie posterior one being highly developed and often as 

 long as the neck, many-branched at the end. A large number 

 of specimens were taken, all of the same size and character ; 

 so that I feel justified in believing it to be a distinct species 

 from the more widely distributed Lernea hranchialis. 



CTiondracantlius clavatus, sp. n. (PI. V. fig. 1.) 



Found only on the gills of Pleuronectes microcephalus. The 

 head is oval, with well-developed antennae ; thorax elongated 

 and club-shaped, with no sign of constriction in the middle, 

 as in C. cornuUis^ Miill., and G. solea, Kroyer. The poste- 

 rior horns are of moderate length. The two pairs of thoracic 

 limbs are small, and the male is like that of C. cornutus. 



Chondracanthus trigloij Blainville. (PL IV. fig. 4.) 

 (C asselliiia, Linn.) 



Plentifully taken from Trigia gurnardus, T. cuculus, and 

 T. Mrundo. The whole anterior portion of the head and so- 

 called neck is buried in a fleshy mass in the substance of the 

 gill, the thoracic portion only showing. The mouth and two 

 pairs of maxillipeds are found at the base of this neck (PI. IV. 

 tig. 4). Male very like that of G. cornutus. The length of 

 the neck-like portion of the head is very variable, sometimes 



