COPEPODS OF THE WOODS HOLE REGION 509 



Distribution. — British seas (T. and A. Scott) ; North Sea (T. 

 Scott) ; Faroe Islands (Kr0yer) ; Norwegian coast, Skager Rak 

 (Olsson) ; Greenland (Hansen). 



Color (preserved material). — Body a uniform dark reddish 

 brown. 



Female. — Head and trunk strongly depressed; first two thoracic 

 segments little more than half the width of the head ; rest of thorax 

 completely fused with a row of six or seven lobes along each lateral 

 margin and around the posterior end. Urosome 2-segmented, the 

 segment representing the abdomen globular and without any caudal 

 rami. First antennae narrowed into a globular tip but not seg- 

 mented; the apical claws of the second antennae curved into a half 

 circle; mandibles falcate and rather coarsely toothed; basal segment 

 of each swimming leg with a broad gibbous wing on either side, dis- 

 tal segment boot-shaped, the leg of the boot attached to the basal 

 segment, the toe pointed outward. Ovisacs cylindrical and a little 

 longer than the body. Total length, 7-7.5 mm. 



Male. — Head fused with first two thoracic segments, wholly cov- 

 ered with the carapace, which does not form a rounded projection on 

 each lateral margin, as in the previous genus. Trunk with three dis- 

 tinct segments, the anal segment nearly as long as the other two; 

 caudal rami conical, acuminate, and completely separate. First 

 antenna 1-segmented, quite short, and tipped with four setae ; apical 

 claw of second antenna long and stout ; mouth parts like those of the 

 female; sAvimming legs uniramose, 1-segmented. Total length, 0.4- 

 0.5 mm. 



Remarks. — This copepod can be identified at once by the peculiar 

 form of the swimming legs. Thus far it has only been found on a 

 single host. 



Family. LERNAEOPODIDAE 



Genus THYSANOTE Kr0yer, 1863 



Female. — Head fused with the thorax or only imperfectly sepa- 

 rated, short, somewhat depressed and curved over ventrally. The 

 rest of the body fused into a trunk, also depressed and enlarged pos- 

 teriorly, with two bundles of ramose processes at each posterior cor- 

 ner, one dorsal and one ventral, and between the ventral bundles a 

 pair of unbranched processes on the midline; no genital process, 

 abdomen, or caudal rami. Branched or unbranched fimbriate proc- 

 esses attached to the posterior margin of the second maxillae and to 

 the body at the base of the second maxillae. First antennae small 

 and indistinctly segmented; second antennae biramose; first max- 

 illa large, tripartite ; second maxillae united only at their tips, bulla 

 mushroom-shaped; maxillipeds large and strong. 

 71937—32 34 



