THE BRACHYURA AND MACRURA OF PORTO RIOO. 
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of posterior margin either angular or marked with a small tooth. Inner lobe of orbital floor produced 
nearly to line of front. Chelipeds narrow, lower surface smooth, upper surface with a scant marginal 
fringe of hair. Arm with upper surface convex and scabrous, anterior margin armed with many 
small denticulated teeth, of which three or four are noticeably larger and sometimes spiniform; 
posterior margin evenly denticulate and terminating in a spine. Outer margin of wrist denticulate, 
inner margin granulate, a longitudinal line of granules through middle of upper surface. Hand with 
denticulate inner and outer margins, with granules along outer margin of upper surface. Thumb not 
bent down or in, prehensile edge with three or four large teeth. Movable finger spinulous on upper 
surface; a spine at terminal third directed distally; prehensile edge finely toothed. Fingers of larger 
claw with a small gape. Last three pairs of ambulatory legs reaching beyond end of arm; first pair 
barely reaching dactylus of second. Legs almost smooth; lower margins of meral joints very finely 
denticulate. The third, fourth, and fifth abdominal segments in the male fused; all separate in the 
female. 
Male: Length of carapace, 6.4 mm.; width, 10.3 mm.; length of cheliped, about 20 mm. 
Mayaguez Harbor, 12 to 18 fathoms, station 6061; 3 males, 5 females, types (Cat. No. 23776). 
Mayaguez Harbor, 7 to 12 fathoms, stations 6058, 6059, and 6060; San Juan Harbor, 4% to 5J fathoms, 
station 6054. 
Up to this time no representative of this genus had been taken in the Atlantic; the type species, 
L. punctatissimus (Owen) , from Lower California, has a much smaller lateral spine, larger postero-lateral 
and posterior spines, and smaller orbits. 
Genus SOLENOLAMBRUS Stimpson. 
Solenolambrus Stimpson, Bull. Mus. Comp. Zool., n, 132, 1871. 
Carapace pentagonal, more or less broad than long; posterior side of pentagon much the shortest, 
the other four sides about equal. Margin acute on all sides, forming a slight crest. The upper surface 
is naked, glossy, strongly convex, and bears four protuberances — one gastric, one cardiac, and two 
branchial. Gastric and cardiac protuberances more or less triangularly pyramidal; branchial protuber- 
ance armed with an acute ridge running obliquely to postero-lateral margin of carapace. Frontal region 
slightly convex, no protuberance on orbital region. Rostrum short and blunt or faintly tridentate. 
Orbits round, a closed fissure above. Basal joint of external antennae about as long as next joint. 
Epistome concave. From the antero-external angle of the buccal area a sharp, elevated, crenulated 
ridge extends to outer base of cheliped, separating concave pterygostomian from subhepatic region, 
which is also concave and channel-like. When retracted, the extremity of hand of cheliped covers 
pterygostomian region, forming the afferent passage. External maxillipeds fit accurately the buccal 
area and closely against each other within; exognath concave, forming part of wall of afferent channel, 
which is defined within by a slight, elevated ridge on outer side of ischium of endognath; the merus 
has a prominent antero-external angle, its surface concave toward antero-interior angle; no notch for 
insertion of palpus, which, except at origin, is concealed behind the other joints of endognath. The 
chelipeds resemble those of Lambrus, except that the fingers are very small and the dactylus is gener- 
ally at right angles with palm when retracted. Terminal joints of ambulatory legs acuminate. Third, 
fourth, and fifth joints of male abdomen soldered together. 
Key to the Porto Rican species of the genus Solenolambrus. 
A. Postero-lateral margin of carapace unarmed between branchial ridge and posterior margin typicus 
A'. Postero-lateral margin with a spine between branchial ridge and posterior margin decemspinosus 
Solenolambrus typicus Stimpson. 
Solenolambrus typicus Stimpson, Bull. Mus. Comp. Zool., ii, 133, 1871; A. Milne Edwards, Crust. R<5g. Mex., 159, 1878; pi. 
xxviii, f. 4, 1879. 
Carapace one-eighth broader than long. Surface coarsely punctate. Protuberances of gastric 
and cardiac regions triangularly pyramidal and acute, with the ridges forming the angles crenulated; 
the posterior ridge in the median line of carapace, the other two diverge from each other in front. 
Cardiac pyramid symmetrical, each of its triangular sides being equal; gastric protuberance not 
symmetrical, the posterior ridge being a short, steep slope, the two anterior ridges being long and 
2d— F. C. B. 1900—6 
