174 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
foramen. The latter is apparently formed by the coalescence of the lips of a deep terminal notch. 
The posterior bilobed margin of the foramen is more elevated than the anterior. In the female the 
telson is more rounded, there is no foramen, and the terminal notch in most cases is obscure, although 
one specimen presents an appearance like other species of the genus. In some there is an appearance 
of thinness of the telson in the region occupied by the foramen of the male. In both sexes the telson 
is globose above, and at its base projects outside the base of the uropods in an epimeral-like process. 
In the male the abdomen and the posterior margin of the last three thoracic segments are orna- 
mented with small, close-set papillae, lacking in the female. In both sexes there are very short hairs 
scattered over the body. 
The eyes are prominent and strongly convex ; first antennae extending beyond first joint of thorax, 
peduncle 3-jointed, first joint stout, somewhat constricted in the middle, second joint short, third 
about twice as long as second, flagellum 7 -jointed, joints gradually decreasing in length, furnished with 
sensory hairs; second antennae reaching beyond second joint of thorax, peduncle 5-jointed, first three 
joints short, fourth longer, fifth longest; flagellum a little longer than peduncle, 11-jointed; mandible 
stout, with 2 dental plates on right side, 1 on the left, a strong molar plate, and a 3-jointed setiferous 
palp, the joints of which decrease in length distally; first maxilla with 4 plumulose setae on tip of first 
joint and a group of stout spines at apex of third joint; second maxilla with 3 plates, each armed with 
about 3 stout curved spines; maxillipeds with a 5-jointed setiferous palp, the terminal two joints slen- 
der, the second and third produced to a rounded lobe at internal distal angles, plate of second joint of 
maxilliped long and broad, and furnished with about 6 stout pectinate setae distally and a hook which 
locks it with its fellow of the other side. 
Thoracic limbs increasing from first to last, all furnished with hairs and spines; fifth joint of first 
pair short and triangular, much longer in second and third pairs, in fourth pair shorter than in the two 
preceding pairs, gradually increasing to the seventh pair, where it is about as long as in the third, but 
much stouter. The seventh joint of all the legs is furnished with a stout terminal claw with a smaller 
one at its base. Uropods broad and leaf-like, rounded posteriorly, and serrate or erenulate, outer ramus 
shorter than inner and folding beneath it, both extending beyond tip of telson. 
About 50 specimens from mangrove roots at Culebra, 3.4 by 1.7 mm. 
Tribe VALVIFERA. 
IDOTEIDT. 
Cleantis planicauda Benedict. 
Body linear, densely granulated, five times longer than broad. Feet folded beneath out of view 
from above. Body lined longitudinally by six more or less broken black lines. The lines on the side 
are more distinct than those above. 
Head subquadrate, partially immersed in the first thoracic segment and rounded on the posterior 
margin; sides parallel, anterior margin emarginate; a deep depression or groove runs from the median 
notch to the center of the head. The eyes are situated near the antero-lateral angle; postoccipital lobe 
distinct; antennse with six segments; first very short and nearly immobile; second very short and 
stout; the third segment is equal in length to the second, but not so stout; the fourth and fifth are of 
equal length and about one-third longer than the second and third segments. The terminal segment 
or flagellum is lighter in color and is armed with short bristles. The length of the antennse is equal 
to the length of the head and first two thoracic segments. The antennulse extend to the middle of the 
third segment of the antennse. The first segment is quadrate; the second subquadrate; the third is 
pear-shaped; the fourth segment is very small. 
The segments of the thorax are nearly equal in length and breadth, the third and fourth being 
but little longer than the others. The epimera. of the second, third, and fourth segments are very small 
and can not be seen from above. On the fifth, sixth, and seventh segments the epimera are large and 
project well behind the margin of the segment in the form of an acute angle. 
The pleon is composed of four segments; the first three are very narrow; the terminal segment 
is elongated with subparallel lines. A marked character of the pleon is its obliquely truncated 
extremity. The oblique terminus is perfectly fiat with a raised margin. 
