COPEPODS OF THE WOODS HOLE REGION 579 



146. Basal segment of first endopod shorter than 2 distal segments 



combined; rostrum lacking; body cylindrical, stout; caudal 

 rami short, wide; muddy bottom, shallow. _ 9 Sarsameira Wilson, 1924 

 Basal segment of first endopod longer than 2 distal segments 

 combined; rostrum present; second endopod not modified 

 in male 147 



147. Caudal rami 10 to 20 times as long as wide; rami of swimming 



legs long and slender; basipods often geniculate, projecting 



laterally; muddy bottom, shallow cf ? Stenocopia G. O. Sars, 1905 



Caudal rami only one to five times as long as wide 148 



148. Exopod of second antenna 1-segmented; terminal segment 



of second endopod with 1 inner, 2 apical setae and 1 apical 



spine 149 



Exopod of second antenna 2-segmented; end segment of sec- 

 ond endopod with 2 inner, 2 apical setae, 1 apical spine; 

 caudal rami as wide as long, and blunt; littoral, among algae. 



cf ? Ameiropsis G. O. Sars, 1907 



149. Middle segment of first exopod without inner seta; anal 



operculum and anal segment with smooth margins; second 

 maxillae with 1 inner lobe; littoral, among algae. 



cT 5 Ameira Boeck, 1865 (p. 244) 

 Middle segment of first exopod with inner seta; anal opercu- 

 lum and anal segment with spiny margins; second maxillae 

 with 2 inner lobes; littoral, among algae. 



(? ? Nitocra Boeck, 1865 (p. 240) 



150. Middle segment of second endopod with 1 seta, of third and 



fourth endopods each with 2 setae; second endopod con- 

 spicuously modified in male; littoral, tide pools. 



cf Dactylopusia Norman, 1903 (p. 206) 



Middle segment of second and third endopods with 2 setae, 



of fourth endopod with a single seta 151 



Middle segment of second endopod with 2 setae, of third and 

 fourth endopods each with a single seta 153 



151. End segment of fifth legs long and narrow; body short, 



depressed; rostrum much reduced; exopod of second 

 antennae 3- or 4-segmented; littoral, moderate depth. 



9 Idyanthe G. O. Sars, 1909 

 End segment of fifth legs fohaceous, short and wide; body 

 stout and compressed laterally; second endopods modified 

 in male 152 



152. Exopod of second antenna 1-segmented; metasome com- 



pressed, but much wider than urosome; segments of fifth legs 

 fused in male, separate in female; littoral, among algae. 



cf Diosaccus Boeck, 1872 (p. 213) 

 Exopod of second antenna 3-segmented; metasome but little 

 wider than urosome; segments of fifth legs separated in both 

 sexes, very wide; moderate depths, among algae. 



cf Amphiascus G. O. Sars, 1905 (p. 215) 



153. Caudal rami narrow, elongate, and widely divergent; body 



also elongate and subcylindrical; urosome fully as wide as 

 metasome; pelagic, surface tow. 



cf 9 Halithalestris G. O. Sars, 1905 (p. 202) 

 Caudal rami short, stout, and parallel 154 



