200 BRITISH PARASITIC COPEPODA. 



are united at the tip is proportionally large. Entire 

 length from the posterior end of the genital segment 

 to the tip of the second maxillipecls about 6 mm. 



The male has not been observed by us. 



Habitat. Parasitic on the gills of the salmon. 

 London Market (IF. Baird). North of Ireland, 1856 

 (W. Thompson). Plymouth (Bassett- Smith). On a 

 diseased salmon from the Firth of Tay (T. Scott). On 

 " the gills of salmon taken in the 'Coquet, 1908"* 

 (E. L. Gill). This species was also obtained on the 

 gills of salmon by Thomas Edward of Banff. f 



A salmon captured in the river Dee near Aberdeen was 

 infested by these parasites : they could be observed adhering 

 to the ends of the gill-filaments in considerable numbers, the 

 white colour of the parasites showing distinctly against the 

 red colour of the gill filaments. (See Plate B, fig. 3). 



5. Lernaeopoda bidiscalis W. F. de Visme Kane. 

 (Plate LXI, figs. 1, 2; Plate LVII, figs. 8-12.) 



1892. Lernseopoda Udiscalis W. F. de Visme Kane. (68) (3) vol. ii, 

 p. 203, pis. ix, x. 



1900. Lernaeupoda Udiscalis T. Scott. (112) p. 172. 



Female. Cephalothorax, seen from above, oblong 

 in shape and rather longer than broad, but in profile 

 somewhat pyriforrn, sloping dorsally upwards and 

 backwards, and terminating abruptly behind ; a con- 

 striction which is distinct, but which can scarcely be 

 described as a "neck," separating the cephalothorax 

 from the genital segment. Genital segment short, 

 considerably enlarged, and nearly as broad as long; an 

 indistinct median dorsal groove present in some speci- 

 mens, the posterior end somewhat truncated, and the 

 postero-lateral corners rounded and slightly lobate. 

 The genital segment provided with two short, inter- 

 mediate, fusiform appendages which spring from the 

 ventral aspect near the origin of the egg-strings. 

 Abdomen nearly obsolete. 



* Cf. ' Crustacea of Northumberland and Durham/ by Brady and 

 Norman (1910). 



f Cf. Smiles, ' Life of a Scottish Naturalist/ 2nd ed. (1877), p. 437. 



