NO. 3 COPEPODA FROM PANAMA MARSH 5 



In the fifth feet of the male (pi. i, fig". 6) the first hasal segments 

 have a row of a few long acute spines on the posterior surface. The 

 second basal segment of the right foot is much wider at the proximal 

 margin than at the distal, due mainly to a curved projection on the 

 inner margin. This curved projection is armed with long acute 

 spines. On the posterior surface a cuticular ridge runs diagonally 

 across the segment, and this is armed over its proximal third with a 

 row of sharp spines. There are two stout hairs about midway of its 

 posterior surface near the outer margin ; opposite these hairs there 

 are on the outer margin a few short hairs, and the distal angles have 

 a few hairs. 



The first segment of the exopodite is as wide as long. There is an 

 acute spine at its outer distal angle, and a stout process on the dorsal 

 surface near the distal end ; this process is about one-half as long as 

 the segment. Upon the middle of the posterior surface is a stout 

 hair about as long as the process, and from the middle of the interior 

 margin projects laterally a long hair. There are a few stout spines 

 near the inner distal angle of the segment. 



The second segment of the exopodite is somewhat shorter than 

 the second basal segment and its outer margin is very nearly the arc 

 of a circle. The lateral spine is situated a little distad of the middle 

 of the outer margin, is straight, about as long as the first segment 

 of the exopodite and denticulate on the margin. The terminal hook 

 is sickle-shaped, about as long as the rest of the exopodite, has two 

 short hairs near its proximal end and is denticulate on the inner 

 margin. 



There is no endooodite on the right foot. 



The second basal segment of the left foot is about as long as broad, 

 and extends somewhat beyond the middle of the corresponding seg- 

 ment of the right foot. Its inner margin is armed with long acute 

 spines, and it has a hair on the posterior surface near the inner distal 

 angle. The first segment of the exopodite is longer than wide, and 

 approximately quadrangular in outline. 



The second segment of the exopodite is about equal in length to 

 the first, is curved, the outer margin being convex and the inner con- 

 cave, and is armed with three blunt spines. The endopodite is com- 

 posed of a single segment and is considerably longer than the first 

 segment of the exopodite. 



In all the specimens seen the right egg sac of the female was appar- 

 ently atrophied. The left sac contains about eight eggs while there is 

 no evidence of eggs in the right sac which is much smaller. A simi- 



