Airr. 4 SENECELLA CALANOIDES JUDAY 3 



The maxilla is foliaceous and bears a number of setae of various 

 lengths, (pi. 1, fig. 6.) 



The first maxilliped (pi. 2, fig. 7) is well developed and is armed 

 with a number of plumose setae. The second maxilliped (pi. 2, fig. 

 8) is elongated and the terminal part is reflexed on the second 

 basal segment. 



The inner ramus of the first pair of swimming legs (pi. 2, fig. 9) 

 has only one segment; it bears three setae on the inner margin and 

 two at the apex. There is a ciliated prominence on the outer mar- 

 gin of this ramus. The penultimate segment of the outer ramus 

 is armed with a spine at its outer distal angle. 



The inner ramus of the second pair of swimming legs (pi. 2, 

 fig. 10) has two segments; the first segment bears a plumose seta on 

 its inner margin and the second has two setae on the inner margin, 

 two at the apex, and one on the outer margin. The first and sec- 

 ond segments of the outer ramus possess a spine of moderate size 

 and one of minute size at the outer distal angle. The third segment 

 has one spine on its outer margin and three terminal spines: the 

 inner terminal spine is large and is armed with teeth on its outer 

 margin. 



The first basal segment of the third pair of swimming legs (pi. 2, 

 fig. 11) bears a plumose seta on its inner margin as does that of the 

 second pair of legs. The first basal segment of the fourth pair of 

 legs (pi. 2, fig. 12) has a spine on the inner margin which is shaped 

 somewhat like a spur: this pair of spines probably has some sexual 

 function since one lies on either side of the genital opening when 

 these legs are reflexed against the body. 



The inner ramus of the third and fourth pairs of swimming legs 

 is three-segmented : the armature is the same as that of the inner 

 ramus of the second pair of legs with an extra seta on the additional 

 segment. The outer ramus of the third and fourth pairs of legs is 

 like that of the second pair. 



The fifth pair of legs is absent in the female. 



Length of female, 2.65 to 2.85 millimeters. 



Churacters of male. — The male is somewhat smaller and more 

 slender than the female, (pi. 2. figs. 13 and 14.) The abdomen is 

 made up of five segments; the first four are about equal in length, 

 but the fifth is small. The genital opening is situated on the left 

 side of the first abdominal segment. The caudal rami are small, only 

 a little longer than broad. 



The first antenna is made up of 25 segments (pi. 3, fig. 15) ; the 

 right antenna is not modified in any way, but is exactly like the 

 left. Each antenna bears 15 sensory appendages. 



The second antenna is like that of the female. 



