90 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
carapace (also at external orbital angle) broad at base, but slender and acute, projecting obliquely 
forward not so far as median sinus. The divisions of the frontal teeth are sharp spines well separated 
and equally advanced. Eye-stalks long, rather slender, extending laterally by the full length of cornea 
beyond antero-external spines. Chelipeds very unequal in adult male of E. rnascarone, probably the 
same in subspecies. In males which I have examined (all small) the chelipeds are feeble and equal, 
not so stout as next two pairs of legs. The first pair of walking legs reach to about middle of dactylus 
of second pair; second pair in male 2.5 times the length of carapace, in the female not so long. 
Dimensions of male: Entire length of carapace, 7 mm.; width, 5.8 mm.; female, entire length of 
carapace, 10.7 mm.; width, 9.4 mm. 
Off St. Thomas, 20 to 23 fathoms, station 6079; off Culebra, 14| fathoms, station 6086. Distributed 
from North Carolina to Florida Keys and Gulf of Mexico, 13 to 37 fathoms; St. Thomas; off Cape St. 
Lucas, 31 fathoms. 
Genus CLYTHROCERUS A. Milne Edwards & Bonvier. 
Clythrocerus A. Milne Edwards & Bouvier, Bull. Mus. Hist. Nat. Paris, v, 387, 1899. 
Carapace subcircular, broadest at middle, thick, dorsally slightly convex or flat, ventrally v^ery 
much swollen, posteriorly exposing the first three abdominal segments. Front short and deflexed. 
Eye-stalks short and rather stout, orbits well defined, with an outer tooth or spine. Antennulse 
folding obliquely and completely retractile in a deep cavity between the front and the inner lower 
angle of orbit. The antennae are short and partly cover the antennular cavities; their basal joint is 
enlarged and valviform. The buccal cavern reaches the front and is completely closed below by the 
outer maxillipeds, the ends of which are sometimes visible in a dorsal view. The palpus of the 
endognath arises from inner surface of, and is completely hidden behind, the merus. The afferent 
openings to the branchiae are situated at antero-lateral angles of buccal cavity and at base of antennae. 
Chelipeds stout. First and second pairs of legs slender, similar, and elongate; the last two pairs short, 
subdorsal, much more feeble and subprehensile, the dactylus folding back against propodus. In the 
abdomen of male the fifth to seventh segments are fused, in the female the sixth to seventh are fused. 
A. Milne Edwards & Bouvier ( loc . cit.) separate from Cyclodorippe the species C. nitida A. Milne 
Edwards, 1880, as the type of a distinct genus, Clythrocerus, on account of the small antennules com- 
pletely retractile in the orbito-antennal cavity, and the valviform ped- 
uncle of the short antennae, which partly covers the antennular cavity. 
The species described below, as well as my Cyclodorippe plana and 
C. granulata, should probably be included in Clythrocerus, although the 
basal joint is not enlarged to the same extent as in C. nitidus. 
Clythrocerus perpusillus, sp. nov. 
Carapace a little broader than long; finely and closely granulous; 
regions slightly marked; surface flat, the front in the same plane; two 
triangular, blunt frontal teeth, separated by a sinus equal to the reverse 
of either of the teeth; the emargination of the orbit is a quadrilateral 
obliquely placed; preorbital angle flat, inconspicuous; postorbital angle a 
little thickened, dentiform; the eye projects beyond line of orbit. A 
small, sharp spine, just before middle of lateral margin; half-way 
between this spine and the orbital angle is a slight indentation. The outer maxillipeds are long, the 
merus joints projecting between the rostral teeth and visible in a dorsal view. Only one cheliped on 
the unique specimen (the right one) ; it is short, about 1.5 times the length of the carapace (when 
flexed, not visible from above) , and stout; the wrist has a prominent antero-external lobe; the hand 
and movable finger have an inner superior crest; fingers bent strongly inward; thumb stouter than 
the movable finger; they meet along their closing edges. Second pair of legs exceed the first pair by 
about the length of dactylus; both pairs slender and flat. In the last two pairs the dactylus is strongly 
curved and about as long as the curved propodus, against the base of which it fits. 
This is a tiny species, the ovigerous female measuring only 2.2 mm. long and 2.5 mm. wide. 
Type locality, off Vieques, 15 fathoms, station 6091; 1 female (Cat. No. 23777). 
female, (a) Outline of cara- 
pace, x 10.66. ( b ) Last two 
joints of fourth leg, x 15. 
