COPEPODS OF THE WOODS HOLE REGION 



219 



Feriiale. — Cephalic segment one-half longer than wide; rostrum 

 triangular and bluntly rounded at the tip; urosome about two- 

 thirds as long as metasome, its segments without spinules; caudal 

 rami wider than long, the inner apical setae with a conspicuous 

 bulge near the base. First antennae 9-segmented, the first four 

 segments of about the same length, the last five much shorter and 

 together scarcely longer than the fourth segment; exopod of first 

 legs definitely shorter 

 than basal endopod seg- 

 ment; end segment of 

 third exopod with four 

 setae and four denticu- 

 late spines; distal seg- 

 ment of fifth legs oval, 

 with six setae, the two 

 apical ones filiform, 

 basal expansion reach- 

 ing center of distal seg- 

 ment, obliquely trun- 

 cated, with five setae. 

 Total length, 0.8-0.85 

 mm. 



Male. — Body more 

 slender and urosome 



longer than in female; second basipod of first legs with a pair of 

 curved and bluntly pointed processes on inner margin; spines on 

 outer margin of first exopod unusually long and denticulate; distal 

 segment of se(?ond endopod with two apical setae, the outer one 

 thickened and spiniform, and a single outer spine, which is flattened, 

 twisted, and emarginate at the tip ; distal segment of fifth legs with 

 six setae, the third inner one filiform, basal expansion much reduced, 

 with two setae. Total length, 0.7-0.8 mm. 



Remarks. — This is the first report of this species outside of the 

 original locality on the Norwegian coast. When alive it can be 

 recognized at once by the transverse brown bands, which remain 

 visible long after preservation, and by the conspicuous bulge on 

 the inner apical setae of the caudal rami. 



AMPHIASCUS PALLIDUS Sars 



Figure 147 



Amphiascus pallidtts Sars, Crustacea of Norway, vol. 5, p. 164, pi. 105, 1906. 



OccutTence. — Found in abundance in the Eel Pond, at Woods 

 Hole, in two of the brackish ponds on Chappaquiddick Island, and 



FifiDRE 146. — Ami)hiascus attenuatus: a, Male, first leg; 

 fj, male, endopod of second leg ; c, female, fifth leg 



