COPEPODS OF THE WOODS HOLE REGION 



245 



Distribution. — British Isles (T. Scott); coast of Norway (Sars). 



Color. — Body transparent with a whitish tinge and without pig- 

 ment markings ; becoming opaque white in formalin ; no eye visible. 



Female. — Metasome and urosome about the same length and not 

 sharply differentiated; cephalic segment pointed anteriorly; anal 

 segment as long as penultimate segment; caudal rami longer than 

 wide and squarely truncated at the tips. 

 Two basal segments of first antennae 

 enlarged and together nearly as long as 

 the rest of the appendage; basal seg- 

 ment of second antenna not divided, 

 the exopod attached to its side near the 

 center ; distal segment of first endopod 

 as long as basal segment, twice the 

 length of the second segment; distal 

 segment of fifth legs twice as long as 

 wide, narrowed apically, with six setae, 

 the outer apical one filiform; basal ex- 

 pansion reaching center of distal seg- 

 ment, with five setae, the second outer 

 one twice the length of the others. 

 Total length, 0.55-0.65 mm. 



Male. — Smaller and more slender 

 than the female; first antennae 9-seg- 

 mented, geniculate, the terminal portion 

 made up of three broad segments, the aes- 

 thetask as bi'oad as these terminal seg- 

 ments and as long as the entire antenna. The rami of the first legs 

 are equal ; the basal endopod segment is slightly longer than the two 

 distal segments, which are themselves equal in length; the middle 

 exopod segment has an inner seta. The fifth legs are much reduced 

 in size, the basal expansion scarcely reaches beyond the base of the 

 distal segment and is armed with three equal setae; the distal seg- 

 ment is twice as long as wide, with six setae, the third outer one 

 filiform. Total length, 0.5-0.6 mm. 



Remarks. — This is a littoral form and has been found hitherto 

 only on i\\% Scottish and Norwegian coast. The short first antennae 

 and the fifth legs in both sexes are the best distinguishing characters. 



AMEIRA TAU (Giesbrecht) 



Figure 163 



Nitocra tau Giesbkecht, Vierter Ber. Comm. wiss. Unters. deutsch. Meere, Jabrg. 



7, p. 117, pi. 1, figs. 9, 13, pi. 3, fig. 13, pi. 4, figs. 2, 11, 29, 1882. 

 Anieira tau Sars, Crustacea of Norway, vol. 5, p. 218, pi. 143, 1907, 



Occurrence. — Found in small numbers in one of the brackish ponds 

 on Chappaquiddick Island, August, 1925 ; washed in great abundance 



Figure 162. — Ameira simplex: a, 

 Male, first leg ; b, male, fifth 

 leg; o, male, first antenna; d, 

 female, fifth leg 



