COPEPOD GENUS RIDGEWAYIA — WILSON 



169 



Leg 1 Leg 2 Leg 3 Leg 4 



It is noteworthy that the figures given in the Hterature for the first 

 three forms do not show this seta on leg 1, but that it is uniformly 

 present in the American forms. This may be a character of signifi- 

 cance on the generic level if it is correlated with other differences, 

 and its presence or absence should be carefully determined in re- 

 examination of the first three species. The presence or absence of 

 this seta in the other legs is inconsistent in typica and canalis, so that 

 it is difficult to accept the evidence as incontrovertible. Here again, 

 future examination of specimens should be critical in this regard. 



Where known, the armature of the first two segments of the exopod 

 of each leg of the incompletely known species agrees with that of the 



Table 2. — Total number of spines and setae on segment 3 of exopod and endopod, 



legs 1-4 of Ridgewayia 



American species; that is, a single outer spine and single inner seta. 

 With the exception of the first leg of the Madras specimen, the endo- 

 pods likewise agree for legs 1-3; that is, one inner seta on segment 1 

 and two on segment 2. The complete absence of setae as shown for 

 the Madras specimen would be very unusual, and, as suggested above, 

 is probably due to incomplete delineation. Leg 4 is unknown for the 

 Madras specimen and for canalis; typica agrees with the Tortugas 

 species, but marki differs from the others in having only one seta on 

 endopod segment 2. 



Where known, the total number of spines and setae on the third 

 exopod segment are like those of the new species, but there is some 



