PORTO RIO AN ISOPOD A. 
167 
Cirolana parva Hansen. 
Body elongate-ovate, between 2.5 and 2.75 times as long as broad. Head broad and produced in 
front in a slender process between the bases of first antennae, deflexed and uniting with the epistome. 
First segment of thorax longest, the next five subequal, the last shortest. 
First segment of pleon hidden, the second sometimes partially so, the fifth longest, hidden at 
sides by the lateral angles of the fourth. 
Telson broad, subtriangular, dorsally uniformly convex; tip rounded and furnished with about 
eight spines. 
First antennae reaching to about end of head, in situ, about as long as peduncle of second antennae, 
flagellum about 11 to 12 jointed. Second antennas reaching to fifth segment, flagellum 25 to 32 jointed. 
Epistome pentagonal, about 1.5 times as long as broad, without spine or process. Clypeus without 
process on anterior margin. Fourth joint of second and third pairs of the thoracic limbs slender. 
Uropods short, reaching hardly to end of telson. Rami subequal, narrow at ends, bifid, their margins 
furnished with spines and a few short setae. 
Specimens from Mayaguez, Puerto Real, Boqueron Bay, Ponce, Arroyo, Culebra, and station 6079, 
20 fathoms. Largest, 8.5 by 3.3 mm.; smallest, 4.6 by 1.3 mm. 
Cirolana obtruncata Richardson. 
Body broad and short, hardly 2.25 times as long as broad; head about twice as broad as long, front 
produced in middle line into an acute process between the bases of first antenna?; first antennae slightly 
longer than peduncle of second antennae, peduncle 2-jointed, flagellum 8-jointed; peduncle of second 
antennae 5- jointed, flagellum broken, longest piece with 12 joints. 
Epistome pentagonal, about 1.5 times as long as broad, uniting with decurved tip of frontal 
process. Mouth parts as usual in the genus; maxillipeds with a 5-jointed palp. 
First segment of thorax about as long as head, the following six about two-thirds as long, and 
equal to one another; fourth, fifth, and sixth joints about equal to one another in width; first segment 
not produced posteriorly, but projecting forward at sides to embrace the eye laterally; the epimeron 
of second segment slightly produced, but rounded, the following segments successively more produced, 
more actually angled and broader, the last reaching to almost posterior dorsal border of fourth 
abdominal segment. All but the second epimeron can be seen in dorsal view. 
. The thoracic limbs are short and stout; the seventh joint is strong and curved, in the second and 
third pairs of legs equal to the sixth joint, and in the other pairs almost equal to it. 
The first abdominal segment is narrow and hidden at the sides by the last thoracic segment; the 
next two joints are about equal in length and with their lateral margins produced, the posterior angle 
of the third embracing the fourth, notched ventrally to embrace base of caudal peduncle and reaching 
beyond the base of the telson; fourth joint produced laterally and covering the sides of the fifth and 
the lateral margin of base of telson. Fifth segment longest, first shortest, the rest equal. Telson nearly 
three-fourths as long as broad, lateral borders nearly straight, broadly truncate behind, the posterior 
border with about 6 short spines and a number of stout seta?. „ 
Peduncle of uropods with inner angle produced; inner lamella broad, rounded behind, reaching 
to about end of telson, its margin armed with short spines and furnished with short setae; outer lamella 
with its inner and outer borders curved, subparallel, rounded behind, furnished with spines and setae 
on outer and posterior margins. 
One specimen from Fajardo, 6 by 2.9 mm. 
BRANCHUROPUS, new genus. 
Eyes well developed, lateral; first antennae projecting beyond head, peduncle 3-jointed, first and 
second joints forming an angle with one another; peduncle of second antenna? 4-jointed; palp of 
maxillipeds small, 1-jointed, sparsely setose; epistome slender, spatulate, emarginate in front. 
Thoracic limbs resembling those of Eurydice. Pleopods confined to middle half of pleon, on each of 
the first four segments Hanked externally by a longitudinal triangular plate, largest on the fourth, 
external to this the pleon concave. 
Uropods resembling the pleopods, hidden beneath the telson; peduncle long, slender. 
This genus shows affinities with Eurydice in the character of both pairs of antenna?, the mandibles, 
the thoracic limbs, and the general shape of the body. It is related to Amiropus in the 1-jointed 
