COPEPODS OF THE WOODS HOLE REGILN 549 



74. Rami of second antennae about equal in length, exopod 8-seg- 



mented; right fifth leg in male 4-segmented, left 5-segmented 

 both legs in female 3-segmented; open ocean. 



c? 9 Bathypontia G. O. Sars, 1905 

 Rami of second antennae very unequal, exopod 7-segmented or 



less 75 



75. Exopod of second antenna longer than endopod; right fifth 



leg of male 3-segmented, left 4-segmented; each leg in female 



3-segmented; Arctic plankton cf 9 Temorites G. O. Sars, 1900 



Endopod of second antenna longer than exopod; male unknown; 

 maxillipeds with dense bundles of setae arranged like brush 

 bristles; open ocean 9 Augaptilina G. O. Sars, 1920 



76. Endopod of second legs 3-segmented 77 



Endopod of second legs 2-segmented 78 



Endopod of second legs 1-segmented 140 



77. Exopod of second antenna half as long as endopod, 7-segmented; 



urosome 3-segmented female, 4-segmented male; fifth legs 

 symmetrical, 5-segmented both sexes; open ocean. 



cf 9 Mecynocera Thompson, 1890 (p. 36) 

 Exopod of second antenna as long as endopod, 6-segmented; 

 urosome 5-segmented in male; fifth legs asymmetrical, left 

 5-, right 4-segmented and swollen; Antarctic plankton. 



cf Temoropsis Wolfenden, 1911 



78. End segments of second to fourth exopods each with 5 setae 79 



End segments of second to fourth exopods each with 4 setae 86 



All the legs without setae; exopod of second antenna 5-seg- 

 mented, twice as long as endopod; fifth legs uniramose, right 



leg 5-segmented, left 2-segmented; Antarctic plankton. 



cf Streptocalanus Brady, 1918 



79. Fifth legs lacking in female, male unknown 80 



Fifth legs present in female and in known males 83 



80. Posterior surfaces of second to fourth legs without spines; 



urosome one-fifth as long as metasome; apical spines of 



exopods cultrated; marine plankton 9 Mimocalanus Farren, 1908 



Posterior surfaces of second to fourth legs armed with spines 81 



81. Head separated from first segment; fourth and fifth segments 



also separated; a crista on the forehead; rostrum stout and 



bifurcate; Antarctic plankton 9 Hypsicalanus Wolfenden, 1911 



Head fused with first segment; fourth and fifth segments also 

 fused; no crista 82 



82. Rostrum stout, bifurcate; first basipod of fourth leg with row of 



16 spines across its posterior surface and 7 on its inner margin; 



open ocean 9 Oxycalanus Farran, 1908 



Rostrum lacking; first basipod of fourth leg with 1 inner seta 

 only, no spines; spines on leg rami confined to the endopods 

 alone; marine plankton 9 Spinocalanus Giesbrecht, 1888 



83. Rami of second antennae equal in length; fifth legs 



uniramose, 3-segmented 84 



Exopod of second antenna definitely longer than the endopod 85 



84. Head fused with first segment; fourth and fifth segments 



partially separated; caudal rami ciliated on inner margin; 



spine of fifth leg smooth; open ocean 9 Farrania G. O. Sars, 1920 



