46 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 113 
row of surface spinules. Exopod about as long as broad, bearing 
a flanged seta on outer distal margin and on distal inner margin an 
ensiform membranous lobe to which is attached laterally a subpyri- 
form membranous lobe. Endopod narrow at base, broader distally, 
bearing 4-jointed setae on distal margin. Adjacent to base of endopod 
a slender stiff seta as long as endopod arises from basipod. 
Cotor: Body without pigmentation except for the orange-red eye. 
Typrs: Holotype, female, USNM 104386; allotype, male, USNM 
104387; and 475 paratypes (321 females, 154 males) from Thalassia 
meadow, Canal de Magiieyes, La Parguera, Puerto Rico, collected 
Feb. 26, 1959 (holotype and allotype), and Feb. 28, 1959 (paratypes). 
This species is named in honor of Dr. Robert E. Coker, Emeritus 
Kenan Professor of Zoology, University of North Carolina, and 
Consultant, Institute of Marine Biology, University of Puerto Rico, 
in recognition of his many studies on copepods and in gratitude for 
his advice and encouragement during the course of the present study. 
The fusion of the head and first pedigerous segment, the absence 
of barbs from the caudal setae and near absence of surface spinules 
from the legs, and the structure of the fifth legs of both sexes serve 
to identify this abundant species. 
Pseudocyclops paulus, new species 
liagures 4-5 
Femate: Length 0.40-0.42 mm. Prosome, viewed dorsally, slight- 
ly more than twice as long as wide. Head in lateral view more convex 
anteriorly than in other Puerto Rican species of Pseudocyclops, sep- 
arated from first pedigerous segment by weak suture. Rostrum very 
strong, curved slightly posteriorly. ‘Third pedigerous segment with 
median sclerotization extending forward from middle of posterior mar- 
ein. Genital segment only slightly produced ventrally; genital openings 
almost lateral; with sclerotization pattern similar to that of P. cokeri. 
Urosome about three-tenths as long as prosome; serrations on 
posterior margins of segments well developed, coarsest in third segment, 
especially in dorsal part. Caudal rami about a half longer than wide, 
without hairs on inner margin. Middle 2 of 4 terminal setae much 
longer and thicker than others. Next-to-innermost seta about 2.5 
times as long as urosome; distal half plumose; basal half armed with 
barbs, 2 on lateral margin and 4-5 on medial margin. Second-from- 
innermost seta shorter and thinner but with similar armature. 
Antenna 1 16-segmented. Mouth parts with only minor differences 
from those of P. coker. 
Marginal spines and setae of legs 1-4 as in P. cokert. Proximal 
outer seta of exopod segment 3 of leg 1 much shorter than distal outer 
seta. Proximal part of outer margin of exopod segment 3 of leg 1 
