COPEPODS OF THE WOODS HOLE REGION 



391 



Family BOTRYLLOPHILIDAE 



Genus BLAKEANUS Wilson, 1921 



Head and first four segments of metasome completely fused and 

 strongly vaulted dorsally; antennae, mouth parts, and four pairs of 

 swimming legs packed closely together in a long groove on the ven- 

 tral surface, surrounded by a raised lip or margin; fifth segment 

 abruptly narrowed and depressed; fifth legs hornlike, on the sides 

 of the segment. Urosome shorter than metasome, 5-segmented; two 

 ovisacs attached to dorsal surface of genital segment; caudal rami 

 flattened laterally and curved dorsally. First antennae 4-segmented ; 

 second antennae 3-segmented; rami of first three pairs of legs, and 

 the exopod of the fourth pair 3-segmented; fourth endopod 2-seg- 

 mented. A single species in the area. 



BLAKEANUS CORNIGER Wilson 



Figure 240 

 Blakeanus corniger Wilson, Proc. U. S. Nat. Mus., vol. 59, p. 11, pi. 5, 1921. 



Occurrence. — A single adult female with ovisacs was taken from 

 the ascidian Cynthia cornea Verrill, in Long Island Sound in 1874. 



Color. — Body of the preserved 

 specimen brownish yellow, ovisacs 

 darker than the body ; no eye visible. 



Female. — Dorsal inflation of meta- 

 some greatest in the fourth segment, 

 where the height is about equal to 

 the length and breadth of the entire 

 inflation. Genital segment cylindri- 

 cal, wider than long; first, third, and 

 fourth abdominal segments the same 

 length, second segment longer. Basal 

 segment of first antenna enlarged 

 into a sort of hand with seven fin- 

 gers, each tipped with a stout seta; 

 remaining three segments of the an- 

 tenna attached like a thumb on the 



outer margin of the hand. Basal segment of second antenna very 

 short, the other two segments much longer and about equal. Total 

 length, 4 mm. 



Male. — Unknown. 



Remarks. — Hansen has reported a second species of the genus from 

 Cynthia rustica in Greenland. The highly vaulted and unsegmented 

 metasome and the 5-segmented urosome are distinctive characters. 



FiGDEE 240. — Blakeanus corniger: a. 

 Female, lateral ; h, female, first an- 

 tenna 



