76 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
slender, tapering, granulate, slightly convex to each other, leaving a narrow interspace at base and 
toward extremity. Basal antennal joint with two short distal spines — one at insertion of second joint, 
the other terminating a longitudinal ridge and just visible beside rostrum in a dorsal view. Chelipeds 
tuberculous; palm slightly compressed, three times as long as wide; fingers slightly gaping in male, 
the dactylus with a broad basal tooth. Ambulatory legs pubescent. 
Dimensions of male: Entire length, 22 mm.; length of rostral horns, 7.5 mm.; branchial width, 
including spines, 10 mm.; without spines, 8.5 mm.; width between tips of preocular spines, 6 mm. 
Specimens were taken by the Fish Hawk as follows: Off St. Thomas, 20 to 23 fathoms, stations 
6079, 6080; off Culebra, 15 to 15j fathoms, stations 6087, 6093; off Vieques, 15 to 16 fathoms, stations 
6091, 6092; off Humagao, 121 fathoms, station 6098. Previously collected at Florida Keys, 2 to 9 
fathoms (Stimpson); between Jamaica and Haiti, 23 fathoms; St. Thomas; off Cape St. Roque, Brazil, 
20 fathoms. 
Genus PICROCEROIDES Miers. 
Picroceroides Miers, Challenger Rept., Zool., xvii, 77, 1886. 
Carapace narrow and rounded behind, constricted behind the orbits, which are tubular and 
project laterally. The width at the orbits equals' or exceeds the greatest width at branchial regions. 
The orbits have a long preocular and a short postocular spine and are emarginate above and below. 
Rostral horns long, slender, and widely separated at base. Abdomen seven-jointed and transversely 
ridged in both sexes; in the male the ridges correspond to similar elevations on the sternum, which 
are rounded and separated by deep depressions. Epistome transverse. Antennular fossettes small, 
deep, and well defined. Basal joint of antenna considerably enlarged and armed with an oblique 
keel immediately behind the next joint; following joints slender. Outer maxillipeds small; merus 
joint distally truncate, antero-external angle obtuse, antero-internal angle emarginate. 
Chelipeds moderately elongate, rather slender; palms slightly compressed and more than twice 
as long as broad; fingers with an intermarginal hiatus at base. Ambulatory legs very slender and of 
moderate length, joints subcylindrical, unarmed; dactyl i slightly arcuate. 
Picroceroides tubularis Miers. 
Picroceroides tubularis Miers, Challenger Rept., Zool., xvii, 77, pi. x, £. 1, 1886. 
Carapace moderately convex, much longer than broad, but little dilated at branchial regions. 
Frontal space concave; gastric region somewhat elevated and obscurely tuberculated; the cardiac 
region bears a rounded prominence and the intestinal region a slender spine; the cervical and branchio- 
cardiac sutures are continuous and form a longitudinal sinus, separating the branchial from gastric and 
cardiac regions. The tubular orbits project laterally to a remarkable degree, and each bears a very 
long preocular and a small postocular spine, and has two notches in the inferior and one in superior 
margin. Rostral spines in adult male four-fifths the length of remainder of carapace ; very slender, 
slightly curved, and remote from each other at base. The basal antennal joint has, besides the antero- 
internal crest, two small teeth on margin of orbit and a third on distal margin. 
Chelipeds unevenly granulated; the outer surface of palm has a slight longitudinal depression near 
upper surface; the dactylus has a strong tubercle near its base. Carapace and ambulatory legs rather 
thinly pubescent; the margins of rostrum and of the free peduncular joints of antennae have some longer 
hairs, some of which are clavate. 
Dimensions of male: Length of rostrum, exclusive of horns, 22.5 mm.; breadth at branchial 
regions, 15.4 mm.; breadth between tips of postocular spines, 17 mm. 
Off Habana, 33 fathoms; between Jamaica and Haiti, 23 fathoms; Fernando Noronha and Bahia, 
shallow water (Miers). Off St. Thomas, 20 to 23 fathoms, station 6079 (Fish Hawk). 
Genus PITHO Bell. 
Pitho Bell, Proc. Zool. Soc. London, in, 172, 1835. 
Otlwnia Bell, Trans. Zool. Soc. London, ii, 55, 1836. 
Piloronus Gistel, Natur. Thierreichs, p. x, 1848. (Substituted for Pitho Bell, said to be preoccupied by Pi/tho Fabricius.) 
Engyzomaria Gistel, loc. cit. (Substituted for Otlionia, preoccupied). 
Microrynchus Desbonne in Desbonne & Schramm, Crust. Guadeloupe, 20, 1867. 
Carapace truncate in front; frontal region wide; rostrum very short, formed of two small teeth. 
Orbits small, tubular, and deep; eyes slender. Outer antenna: short; basal article lamellose, forming 
floor of orbit; second article fiat, short, and broad, especially in terminal portion; third article fiat, 
