50 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Lupella forceps (Fabricius). 
Cancer forceps Fabricius, Ent. Sys. auct. et emend., it, 149, 1793. 
Lupa forceps Leach, Zoo! . Misc., I, 123, pi. liv, 1814. 
Carapace flat, hexagonal, finely granulate. Epigastric and epibranchial lines rather well marked. 
Posterior margin very wide. Antero-lateral margin armed with eight very small, sharp teeth, separated 
by wide sinuses; lateral spine long, slender, and extending directly outward. The front (between 
antennae) is four-toothed, middle pair small and subacute, outer pair longer and obtuse. Inner orbital 
teeth broad, obtuse; epistomal tooth short, not surpassing the front. Chelipeds smooth and remark- 
ably long and slender; the arm equals width of carapace near base of lateral spines, hand twice as long. J 
Anterior border of arm with four to six spines; posterior border with a spine at extremity. Wrist 
with a spine at inner angle, another on outer surface. Hand cylindrical, slender, with a spine above 
articulation with carpus and another above articulation with dactylus. Fingers very slender, almost 
filiform, with numerous small teeth on their occludent edges. Ambulatory legs very compressed; 
merus of swimming pair short, almost orbicular, armed above and below with a terminal spine; 
propodus elongate; dactylus oval. In young males the fingers are shorter, and in females still shorter. 
Dimensions of male: Length of median sinus, 19 mm.; extreme width, 48.4 mm.; width at sinus, 
between lateral spine and next tooth, 33.5 mm. 
West Indies. Uncommon. Porto Rico: San Juan Harbor, between Palo Seco and Catano; 
Mayaguez, in seine; Mayaguez Harbor, 7 to 7',- fathoms, stations 6058 and 6059; off Puerto Real, 82- 
fathoms, station 6074; Mayaguez and San Juan (Gundlach). 
Genus ARENiEUS Dana. 
Arenseus Dana, Am. Jour. Sci. (2), XII, 130, 1851. 
Closely allied to Portunus , with which it is sometimes united. Differs in having the palate 
smooth or without a longitudinal ridge. Superior fissures of orbit open, V-shaped. Abdomen in male 
narrower than in typical Portunus, yet not j_-shaped as in Cul/inectes. 
Arenaeus cribrarius (Lamarck). 
Portunus cribrarius Lamarck, Hist. Nat. Anim. sans Vert., v, 259, 1818. 
Arenxus cribrarius Dana, Crust. U. S. Expl. Eped.. 1 , 290, 1852; pi. xvm, f. 2, 1855. 
Carapace wide and almost smooth to the naked eye, but through the lens it appears closely 
covered with fine granulations. Front narrow, much less advanced than outer orbital angles and 
armed with six teeth (between the orbits), the two median more prominent than intermediate ones, 
which are partly coalesced with median; outer pair obtuse, wide, and separated from preceding by a 
wide cut. Superior border of orbit divided into three lobes by two wide incisions; inferior orbital 
border much advanced at inner end. Antero-lateral teeth wide and covered below with hairs which 
screen the interspaces; the first narrower than the Jast; lateral horn strong, pointed, and a little longer 
than space occupied by two last teeth. Inferior orbital border interrupted by a wide external fissure. 
Pterygostomian regions, epistome, and antennal region covered with hairs. Endostome smooth. 
Merus of outer maxillipeds narrowing much distally. Chelipeds short. Three spines arm the merus 
in front; one spine, almost tubereuliform, is at a little distance from end on posterior border. Wrist 
with two spines, one inside, the other out. Hand short and swollen, crossed by granulous carinas and 
surmounted by two short spines, one above articulation with wrist, the other above movable finger. 
Ambulatory feet not long, their last articles very wide. Swimming feet very stout, the merus some- 
what rounding and unarmed. Sternum smooth, abdomen of male triangular, margins a little sinuous, 
last article very pointed. 
Carapace and chelae violet or yellowish brown, covered with a multitude of round spots, either 
white or light yellow (A. Milne Edwards). These spots are present in alcoholic specimens. 
Dimensions of male: Length to median sinus, 44.5 mm.; length to tip of median pair of teeth, 
46.2 mm.; entire width, 103.6 mm. ; width to sinus in front of lateral spine, 80.5 mm. 
From New Jersey to Rio de Janeiro; Gulf of Mexico. Porto Rico: San Juan Harbor at Palo 
Seco and between Palo Seco and Catano; Mayaguez; Boqueron Bay ; Playade Ponce; Arroyo; Vieques; 
Aguadilla and San Juan (Gundlach). 
