THE BRACHYURA AND MACRURA OF PORTO RICO. 
89 
Speloeophorus nodosus (Bell). 
Oreophorus nodosus Bell, Trans. Linn. Soc. London, xxt, 307, pi. xxxm, fig. 8, 1855. 
Spelceophfirus nodosus A. Milne Edwards, Ann. Soc. Entom. France (4) v, 149, 1865. 
Spelseophorus nodosus Stimpson, Ann. Lyc. Nat. Hist. N. Y., x, 119, 1871. 
Carapace about one-fifth broader than long, pentagonal, postero-lateral angles rounded; surface 
covered with crowded granules and nodose; an elevated protuberance on hepatic region, a transverse 
line of nodules across middle of carapace and one above each posterior cavity; a median ridge on gastric 
region. Hepatic region is thick, its margin rounded; subhepatic region with a prominent bunch of 
granules; subbranchial region with two similar bunches of granules; branchial margin with a thick 
anterior lobe and a sharp-edged postero-lateral lobe. Upper wall of posterior cavities thick, lower 
edge of this wall set in considerably from upper or external edge. Lower posterior margin of carapace 
bilobed, the lobes more distinctly marked in male than in female. Front thick, bilobed, somewhat 
bimarginate. Orbit with three closed fissures; a broad space between orbit and buccal cavity. Entire 
lower surface of carapace, as well as surface of chelipeds and legs, densely granulous. Merus of outer 
maxilliped more than half the length of ischium; exognath of nearly the same width throughout its 
length; its outer margin is nearly straight. Arm of chelipeds cylindrical, bilobed on outer margin, 
proximal lobe narrow and tuberculiform, distal broad. Hands are dilated, outer margin cristate, 
entire; fingers thin, flat, grooved, fitting closely together. Ambulatory legs cristate, crests dentate or 
narrowly lobed. The abdomen of the male has on the penult segment a backward-pointing spine at 
its proximal end. Dimensions of male: Entire length, 12.7 mm.; width, 14.6 mm. 
Mayaguez Harbor, 4 to 6 fathoms, one female, station 6065. Type locality unknown; Jamaica 
(Stimpson, Rathbun) ; St. Thomas (Copenhagen Mus.); Guadeloupe (Geneva Mus. ). 
Family D 0 RIPP 1 D 7 E Milne Edwards, 1837; White, 1847. 
Carapace short, so that the first two or three abdominal terga are completely exposed in the 
dorsal plane of body. The last two pairs of legs are short and feeble, and raised on the dorsal surface 
of carapace. Antennaj large. The verges of the male are exserted from the sternal plastron. The 
afferent channels to the branchiae are found either in front of the bases of the chelipeds or not. 
Key to the Porto Paean genera of the family Dorippidx. 
A. The external maxillipeds leave all the anterior part of buccal cavern uncovered Ethusa 
A'. The external maxillipeds do not leave any appreciable portion of buccal cavern uncovered Clythrocerus 
Genus ETHUSA Roux. 
Ethusa Roux, Crust. M6dit., p. (81) , 1828. 
Carapace very flat, truncate-oblong and broadest behind, covering little more than first two 
thoracic sterna, hepatic region small. The front consists of two laminar teeth, each of which is bifid. 
There is a long, flat tooth or spine at antero-external angle of carapace. The antennules fold obliquely; 
they are large and project beyond their fossse. The antennte have a long flagellum ; their basal joint 
is inserted between eye-stalk and basal antennular joint, but on a slightly lower level. The buccal 
cavern is elongate-triangular and does not extend to the front; the external maxillipeds cover only its 
basal three-fourths, but the distal part is closed in by stout foliaceous processes of first maxillipeds. 
The palp of external maxillipeds arises from the summit of the merus and is completely exposed in 
flexion. The afferent branchial orifices are wide openings immediately in front of bases of chelipeds. 
Chelipeds in adult male often unequal. First and second pairs of ambulatory legs long and rather 
stout. The last two pairs short and rather slight; they arise much higher than the other legs, and 
have a small hook-like dactylus folding backward. The abdomen of male usually consists of five 
pieces, the third to fifth segments being fused; that of female consists of seven separate segments; the 
first three segments are visible in a dorsal view. 
Ethusa mascarone americana A. Milne Edwards. 
Ethusa americana A. Milne Edwards, Bull. Mus. Comp. Zool., vm, 30, 1880. 
Ethusa mascarone americana Rathbun, Proe. Biol. Soc. Washington, xi, 109, 1897. 
Carapace somewhat lyre-shaped; length about one-fifth greater than width in male, one-seventh 
greater in female; surface smooth and finely pubescent. Regions are well marked; branchial regions 
moderately swollen; they and the cardiac region are equally high. Spine at antero-external angle of 
