COPEPODS OF THE WOODS HOLE liEGILN 617 



28. Neither caudal rami nor posterior processes present 29 



Posterior processes present, but no caudal rami 31 



Caudal rami present, but no posterior processes; neck 2-seg- 

 mented; second maxillae on a level with the dorsal surface; 

 eyes of sharks 9 Ommatokoita Leigh-Sharpe, 1926 



29. Abdomen present, usually segmented; trunk also more or less 



segmented; exopod of second antenna 2-segmented; a partial 



carapace; gills, fresh-water fishes 9 Achtheres Nordmann, 1832 



No abdomen; trunk not segmented; exopod of second antenna 



1-segmented 30 



30. Head with a carapace; no genital process or abdomen; first 



antennae 2-segmented; distal three-fourths of second maxillae 



fused; scales of fishes 9 Lernaeopodopsis Hansen, 1923 



Head without a carapace; a genital process but no abdomen; 

 first antennae 3-segmented; second maxillae separate to their 

 tips; gills of fishes 9 Salmincola Wilson, 1915 



31. Two posterior processes ventral to ovisacs; second and third 



segments separated from trunk; exopod of second antenna 



usually 2-segmented; skin of sharks 9 Lernaeopoda Blainville, 1822 



Two posterior processes dorsal to ovisacs; second and third 

 segments fused with the trunk; exopod of the second antenna 

 usually 1-segmented; gills of rays 9 Lernaeopodina Wilson, 1915 



32. Head with a neck; trunk with longitudinal rows of knobs; 



first antennae 2-segmented; second antennae biramose, rami 



1-segmented; gill cavity of fishes 9 Basanistes Nordmann, 1832 



Fused head and trunk smooth, without knobs; first antennae 

 2-segmented; second antennae uniramose, 1-segmented; 

 second maxillae fused distally; gills of fishes. 



9 Nectobrachia Fraser, 1920 



33. Second maxillae shorter than head, three-fourths fused, with 



branching horns instead of a bulla; mouth tube minute and 



depressed; gills of ray 9 Brianella Wilson, 1915 



Second maxillae twice as long as head, entirely separate, with 

 a normal bulla; mouth tube large, projecting visibly; gills of 

 skates 9 Thomsonella Wilson, 1915 



34. Trunk or second maxillae, or both, with deeply incised fimbriate 



processes ; head in line with the trunk 35 



Neither trunk nor second maxillae with fimbriate processes; 



head inclined to trunk, rarely in line with it 36 



35. Head short, stout, and straight; anterior fimbriae on second 



maxillae, posterior on distal end of trunk; ovisacs concealed; 



gills of fishes 9 Thysanote Kr0yer, 1863 (p. 509) 



Head long, slender, and arched; fimbriae all on lateral margins 

 of trunk, none on end; ovisacs plainly visible dorsally; mouths 

 of fishes 9 Thysanotella Wilson, 1915 



36. Head short and wide, in line with trunk or flexed 37 



Head long and wormlike, and always curved or flexed 38 



37. Head separated from trunk by a short neck; second maxillae 



completely fused, with a bulla; no caudal rami or processes; 



lips of fishes 9 Cauloxenus Cope, 1872 



Usually a long neck; second maxillae separate, ending in clasp- 

 ing hands or a bulla; 2 dorsal posterior processes on trunk; 

 spiracles of fishes 9 Charopinus Kr0yer, 1863 (p. 511) 



