COPEPODS OF THE WOODS HOLE REGION 479 



Color. — Body a clear yellowish white, usually with a brownish 

 tinge in the male ; Q.^g strings light brown. 



Female. — Carapace rhomboid with rounded corners, narrowed an- 

 teriorly and posteriorly, posterior margin somewhat truncated ; lateral 

 lobes of second segment curved backward ; fourth and fifth segments 

 with transverse grooves near the center ; genital segment with a trans- 

 verse groove near the anterior end. Segments of first antenna sub- 

 equal; second antenna very stout and extended diagonally forward, 

 the segments indistinct; maxillipeds with a stout apical claw, shut- 

 ting down against two small spines on the inner margin of the basal 

 segment ; legs armed with spines, no setae. Total length, 15-18 mm. 



Male. — Smaller than female, the head relatively larger, the geni- 

 tal segment considerably shorter; no transverse grooves on the tho- 

 racic segments. Endopod of second legs very short and wide ; third 

 legs each a 1-segmented lamina wider than long, with a lobe at the 

 end suggesting a second segment. Total length, 10-13 mm. 



Remarks. — This parasite is apparently confined to the sturgeon, 

 and remains upon its host as the latter migrates up the rivers of 

 northern and central Europe. In the present area, however, it is a 

 salt-water form. 



Family LERNAEIDAE 



Genus PENICULUS Nordmann, 1832 



Female. — Head fused with the first segment, often showing lateral 

 lobes, but without horns or processes; second and third segments 

 narrowed, flattened dorsoventrally, and chitinized, forming a short 

 neck; fourth segment widened and swollen; fifth and genital seg- 

 ments and abdomen fused into a cylindrical trunk; caudal rami 

 minute, laminate, and armed with setae. First antenna filiform with 

 few segments; second antenna strongly chelate; a long conical and 

 retractile proboscis; mandibles and maxillae but no maxillipeds; 

 basal plates only of the first four pairs of legs, the rami obsolete ; no 

 fifth legs. One species. 



Male. — Unknown. 



PENICULUS CLAVATUS (Miiller) 



Figure 286, &, c 



Lemaea clavata Muller^ Zoologia Danica, p. 38, pi. 33, fig. 1, 1779. 

 Peniculus clavatus Wilson, Proc. U. S. Nat. Mus., vol. 53, p. 46, pi. 1, 1917. 



Occurrence. — Taken from the fins of therosefish {Sehastes marinus) 

 captured off Cape Ann by the steamer Speedivell in 1878. 



Distnhution. — Coast of Norway (Miiller, Olsson) ; Greenland 

 (Kr0yer) ; Davis Strait (Hansen). 



Color (preserved material). — Head and neck a grayish yellow, 

 trunk a dark cinnamon-brown; egg strings a lighter brown. 



