COPEPODS OF THE WOODS HOLE REGION 



223 



Distribution. — Coast of Norway (Sars). 



Color. — Body whitish and transparent, without pigment mark- 

 ings of any sort; eye deep ruby red. 



Female. — Body rather slender; cephalic segment half the length 

 of the metasome ; rostrum very long and narrow, curved downward, 

 and sharply pointed; urosome about as long and nearly as wide as 

 metasome ; genital segment with scarcely a trace of division ; caudal 

 rami quadrangular, wider than long, apical setae only slightly thick- 

 ened at their bases ; exopod of first legs a trifle shorter than the basal 

 endopod segment, middle segment 

 without an inside seta; distal seg- 

 ment of third exopod with three 

 spines and three setae ; distal segment 

 of fifth legs elongate-ovate, pointed 

 at the tip, with six setae, the second 

 and third inner ones filiform; basal 

 expansion narrow triangular, reach- 

 ing beyond the center of the distal 

 segment, with five setae, the four in- 

 ner ones equal. Total length, 0.7- 

 0.85 mm. 



Male. — Second basipod of first legs 

 with a long spine at the inner corner, 

 reaching beyond the center of the 

 basal endopod segment ; second endo- 

 pod as long as the exopod with a 

 short apical spine and two long outer spines, reaching beyond the 

 tip of the apical one; distal segment of fifth legs short, as wide as 

 long, with five setae, the two terminal ones filiform, basal expansion 

 reaching the tip of the distal segment, with two equal setae. Total 

 length, 0.6-0.T5 mm. 



Remarks. — As Sars has pointed out, this species resembles longi- 

 rostrls, but it has a broad shallow sinus on the lateral margins of the 

 cephalic segment at the anterior corner, and the first legs of the male 

 are markedly different. The specimens from Cuttyhunk Harbor 

 were living on the outside surface of compound ascidians on the 

 piles of the wharf. 



Figure 150. — Amphiuscus sinuatus: 

 a, Male, second leg ; b, female, 

 fifth leg ; c, male, fifth leg 



AMPHIASCUS DACTYLIFER, new species 



Plate 5, n-fi 



Occurrence. — Found in abundance in two of the brackish ponds on 

 Chappaquiddick Island, July, 1926, and sparingly in Quisset Pond, 

 Falmouth, August, 1927. The male holotype is U. S. N. M. No. 63425. 



