176 BRITISH PARASITIC COPEPODA. 



8. Chondracanthus nodosus (0. F. Miiller). 

 (Plate LII, figs. 1-3 ; Plate XLVIII, figs. 13-16.) 



1777. Lernaea nodosa O. F. Miiller. (85) p. 40, pi. xxxiii, fig. 5. 

 1816. Lernuea nodosa Lamarck. (72) p. 231. 

 1822. Lernentoma nodosa Blainville. (24) p. 125. 

 1838. Chondracanthus nodosus Kroyer. (70) p. 133, pi. iii, fig. 2. 

 1840. Chondracanthus nodosus M. Edwards. (43) p. 503. 

 1863. Chondracanthus nodosus Kroyer. (71) p. 258. 

 1909. Chondracanthus williamsoiti T. Scott. (118) p. 76, pi. iii, figs. 

 8-17. 



Female. Body flattened, and of an ovate form when 

 seen from above ; cephalon subquadrangular but with 

 a shallow rounded projection on each side. A slight 

 constriction separating the cephalon from the thorax. 

 The genital segment, which is coalescent with the 

 thorax, broadly ovate and flattened, and having the 

 lateral margins coarsely crenulated or lobate, with six 

 rounded but somewhat irregular projections on each 

 side, the second and the last three being more promi- 

 nent than the others ; the posterior end terminating in 

 a narrow median lobe. Abdomen much reduced in 

 size, and of a rounded form. 



Antennules small, uniarticulate, and rather rudi- 

 mentary in structure. Antennae short and armed with 

 strongly-hooked terminal claws. Mandibles similar 

 to those of Ghondr acanthus cornutus ; both pairs of 

 maxillipeds small ; the first pair very similar to those 

 of the species named, being composed of a stout basal 

 part and a straight spine-like claw finely serrated on 

 the inner edge ; the second pair more elongated and 

 narrow, and each armed with a short, stout, terminal 

 claw and a small rounded process. Both pairs of 

 thoracic legs rudimentary and nearly similar in 

 structure ; each limb consisting of a short and broad 

 basal part, gibbous on both sides, which bears a small 

 oblong distal process separated from the basal part by 

 a narrow constriction. Egg-strings tolerably elongate 

 and stout, and containing many ova. Length about 

 7*5 mm. Colour opaque white with a tinge of red. 



Plate LII, fig. 2, represents a young female 



