﻿COPEPOD GENUS PUPULINA (CALIGOIDA) — ^WILSON 261 



Lateral prehensile hook stouter than that of female, about as long 

 as terminal claw of second antenna; the setae of basal papillae long, 

 slender, and unbranched. Antenna 2 (pi. 14, fig. 6) with a cuticular 

 process on basal segment; a stout, curved spine and small laminate 

 process on segment 2 ; a 4-jointed, broadly stalked seta on segment 3 ; 

 terminal claw stout and strongly curved, though relatively short, the 

 seta at its base long and 2-jointed. First maxilla (pi. 15, fig. 9) having 

 the basal outside portion of the outer piece widened transversely with 

 a slight distal extension inside ; papilla (pi. 15, fig. 10) of two parts, the 

 upper with a very short spine, the lower with two subequal setae, the 

 outer seta very broad and set on a stout basal stalk ; inner piece slender 

 throughout, having at its distal outer third a very small curved spine. 

 Maxilliped (pi. 15, fig. 13) with a small lamina at the middle of the 

 basal segment, and an unusual clawlike process with a divided tip, 

 attached basally. 



Leg 4 (pi. 15, fig. 18) with broad basal segment set with stout spin- 

 ules and long coarse hairs. Segments 2-4 with inside spines and outer 

 marginal laminae as in female; apex of segment 4 not so squarely 

 truncated, terminal inside spine slender and curved, comparatively 

 longer than that of the female. 



Development Stages : Three development stages of the female are 

 represented in the collection. None is so immature as the earliest 

 stage (a) described for Pupidina -fiores. The youngest, however, cor- 

 responds very closely to stage h of P. -fiores^ and so is likewise des- 

 ignated as stage 6. Stage c is probably the one immediately follow- 

 ing this in natural development. Other forms designated as young 

 females are considered to represent early growth stages of the adult 

 copepod. 



No filament was ascertained to have been present in any of the speci- 

 mens, but there is a small ventral structure that is interpreted as being 

 a filament gland. 



Stage h (pi. 14, fig, 4) : Two specimens, to one of which a male is 

 attached to the dorsal neck of the genital segment, clinging by means 

 of the claws of its second antennae. 



Total length, 7.8 mm.; cephalothorax, 5.5 mm.; posterior part of 

 body, including caudal rami, 2.3 mm. All the first three thoracic 

 segments incorporated in the carapace, which is a little longer than 

 wide; frontal plates distinct. 



Processes of genital segment reaching almost to the end of abdo- 

 men. Abdomen 2-segmented, the anal segment not being differen- 

 tiated. Caudal rami having the short, broad form characteristic of 

 the species ; in this stage they are almost as long as the abdomen. 



All of the appendages completely segmented, but not so strongly 

 developed as those of the adults. The inner piece of the first maxilla 



