COPEPODS OF THE WOODS HOLE REGION 



411 



Remarks. — Probably nowhere among the parasitic copepods has 

 there been any greater attempt to create several species out of one 

 than in the present instance. This is fully discussed in the reference 

 given above ; here it is sufficient to say that the species may be recog- 

 nized by the characters given in the two keys on pages 409, 410. 



LEPEOPHTHEIRUS NORDMANNII (MUne Edwards) 



FiGTJEE 258 



Caligus nordmannii Milne Edwards, Histoire natux'elle des Crustaces, vol. 3, 

 p. 455, 1840.— Wilson, Proc. U. S. Nat. Mus., vol. 28, p. 623, pi. 19, 1905. 



Occurrenoe. — Found on the outside surface of the sunfish at Woods 

 Hole. 



Distribution. — Mediterranean (Heller, Stossich, Milne Edwards, 

 Richiardi, Elwes) ; English seas (White, Baird, T. Scott) ; California 

 coast (Wilson). 



Color. — Body a uniform yellowish white, covered with tiny dots of 

 reddish brown. 



Female. — Carapace orbicular, as wide as long ; fourth segment half 

 the width of the genital segment, strongly narrowed in front of the 

 fourth legs; genital segment less 

 than half the width of the cara- 

 pace, with wide posterior lobes, 

 but without leg rudiments. Ab- 

 domen spindle-shaped, half as 

 long as the genital segment; 

 caudal rami long and slender. 

 Branches of the furca long, di- 

 vergent, and transversely wrin- 

 kled; fourth leg 4-segmented, 

 with six spines and no seta, 

 reaching well beyond the center 

 of the genital segment. Total 

 length, 10-12 mm. 



Male. — Carapace longer than 

 the rest of the body ; fourth seg- 

 ment longer and narrower than in 

 the female ; genital segment flask- 

 shaped, longer than wide, nar- 

 rowed anteriorly and deeply concave posteriorly, with two pairs of 

 pointed posterior processes carrying leg rudiments. Abdomen 2-seg- 

 mented, the basal segment the wider, the end segment the longer ; cau- 

 dal rami narrow and curved like parentheses. Total length, 5-6 mm. 



Remarks. — This species is apparently confined to the sunfish, and 

 may be looked for whenever that peculiar fish is found. 



Figure 258.— Lepeophtheirus nordmannii: 

 a. Female, dorsal (drawn by Bmerton) ; 

 i, female, fourth leg 



