824 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Zonophryxus retrodens Richardson, sp. nov. 
Body of female (fig. 4 a, b) rather quadrangular in shape, with only faint traces of segmentation 
on the dorsal surface. Dorsal surface very convex, with no distinct boundary between the three chief 
divisions of the body, the head, thorax, and abdomen being continuously one. On the ventral side a 
border surrounds the entire body, and is wider in the cephalic region. 
The cephalic part projects in front as a broadly rounded area or border. On either side of the 
body on the anterior half, the lateral border is incised with three small indentations, marking off the 
head from the first thoracic segment, the second from the first, and the third from the second. Five 
indistinct lines on the dorsal surface of the anterior half of the body mark off the head from the thorax 
and outline the first four thoracic segments. The posterior half of the body shows no trace of segmen- 
tation on the dorsal surface. The posterior margin of the border at the terminal part of the body is 
produced in 9 triangularly-shaped processes. These processes are arranged four on either side of a 
median one, and undoubtedly indicate the 5 coalesced abdominal segments. 
The legs are in 5 pairs and are confined to the anterior half of the body on the ventral side. 
The incubatory lamellae (fig. 4 d) consist of 5 pairs of plates, meeting in the median ventral line. 
The fifth pair overlap the second, third, and fourth pairs. 
Only a single pair of pleopoda are present, which fold back upon the lower portion of the fifth 
pair of incubatory plates. 
From the oral area there extends on the ventral side a long process, which 
subdivides and terminates in two lobes, one on either side, beneath the 
incubatory lamellae. 
The male (fig. 5) has the head fused with the first thoracic segment. The 
other 6 segments are free and distinct. All the segments of the abdomen are 
consolidated into one, which is somewhat oval and pointed posteriorly. All 7 
pairs of legs are present, the first pair being attached to the cephalic segment. 
Head large, concave on its dorsal surface, the anterior margin produced into a 
rounded process, which is directed upward. Eyes wanting. No pleopoda or 
uropoda. 
Only one specimen was obtained by the TJ. S. Fish Commission steamer 
Albatross from the south coast of Oahu Island, Hawaiian Islands, in 1902. The 
specimen was unattached. 
Type in U. S. National Museum. Cat. No. 28970. 
Family BOPYRM. 
Subfamily EN TO PH I LINAS. 
ENTOPHILUS Richardson, gen. nov. 
Type, Entophilus omnitectus Richardson, sp. nov. 
Body of female rather asymmetrical. Dorsal surface with segmentation in- 
dicated by depressions more or less clearly defined. All 7 pairs of legs present. 
Marsupium bounded ventrally by 5 pairs of incubatory lamellae. Seven pairs of 
plates, overlapping the dorsal surface and attached only to the bases of the legs, extend in two 
longitudinal series, one on either side of the thorax; these plates probably correspond to the epimeral 
plates. 
Two series of 5 plates each are present on either side of the abdomen, meeting along the median 
dorsal side and surrounding the abdomen at the sides, the lower plates nearly meeting again on the 
ventral side in the median line. Terminal part of abdomen truncate. 
Pleopoda consisting of 5 pairs of double-branched lamellae. Uropoda absent. 
Male with the 6 segments of the abdomen clearly and distinctly defined, the last segment pro- 
vided with a pair of single-branched uropoda; all the preceding segments of the abdomen provided 
with a pair of single-branched, well-developed pleopoda. Seven pairs of thoracic legs attached to the 
7 thoracic segments. 
Pig. 5 . — Zonophryxus 
retrodens. Male, x 
