THE BRACHYURA AND MACRURA OF PORTO RICO. 
23 
Tribe CYCLOMETOPA or CANCROIDEA. 
Carapace usually broader than long, regularly arched in front, and not rostrate. Epistonie short 
and transverse; outer maxillipeds with the fifth joint articulated at the inner front angle of the fourth. 
Branchiae nine; efferent channels opening at the sides of the endostome or palate. Genital organs of 
male inserted at bases of last pair of trunk legs. 
Family P0TAM0N1D/E Ortmann, i8(>0. Fresh-water Crabs. 
Carapace more or less dilated at branchial regions. Third maxillipeds with palpus articulated at 
or near front inner angle of merus or at its apex. Terminal segments of walking legs usually spinulif- 
erous. The verges of the male pass directly through the basal joint of the fifth pair. 
Species fluviatile or living in damp earth away from the sea. 
Genus EPILOBOCERA Stimpson. 
Epilobocera Stimpson, Ann. Lye. Nat. Hist. N. A'., vii, 234, 1860. 
Carapace transversely oval. Side margins tuberculate or dentate. Epigastric lobes and cervical 
suture present. Front inclined, generally bilobed, either straight or slightly arched, and with or 
without a superior margin. Inner suborbital lobe always present. Outer maxillipeds with merus of 
endognath broader than long, its outer margin either arcuate or angular. Exognath exceeding in length 
ischium of endognath. A tooth or spine in efferent branchial channel. Dactvli of ambulatory legs 
with numerous slender spines. 
Epilobocera sinuatifrons (A. Milne Edwards). 
Boscia sinuatifrons A. Milne Edwards, Ann. Soc. Entom. France (4), VI, 205, 1866. 
Pseudothelpliusa sinuatifrons Smith, Trans. Conn. Acad. Sci., n, 147, 1870. 
Epilobocera sinuatifrons Rathbun, Proc. U. S. Nat. Mus., xxi, 529, 1898. 
Carapace very broad; cervical sutures very deep ; epigastric lobes prominent. Front narrow, with 
a superior crest, which projects beyond inferior and is nearly straight, emarginate at middle and 
tuberculate; lower margin sinuous, a little deeper at outer ends. Orbits about 1.5 times as wide as 
long, tuberculate, with a large outer notch. Antero-lateral margin with small, irregular, blunt teeth, 
the one behind cervical suture a little larger; margin also interrupted a little ways behind the orbit. 
Merus of outer maxilliped subquadrate, with an antero-external angle. Exognath slightly overlapping 
merus of endognath. Tooth of efferent branchial channel short and broad. Clielipeds very heavy and 
very unequal, especially in the male. Merus with upper margin rounded, rugose; inner margin with 
stout blunt teeth increasing in size distally; lower margin tuberculate. Carpus with an inner tooth, 
blunt and spiniform. Palm of larger hand swollen, of smaller with nearly parallel margins. Dactylus 
longer than upper margin of palm. Fingers stout, covered with large, dark granules, their prehensile 
edges not meeting when closed, and armed with stout and irregular teeth with white tips. Meri of 
ambulatory legs roughened above; carpal joints spinous distally; propodal joints spinous on margins; 
dactyli with five rows of large spines. 
Dimensions of male: Length, 53.7 mm.; width, 94 mm.; width at outer orbital angles, 44.2 mm.; 
width of front at superior crest, 24 mm. ; length of larger palm above, 36.5 mm. ; width, 37 mm. ; length 
of dactylus, 48.3 mm. 
Porto Rico: Oaguas, Rio Grande; San Juan market ( Buragina ). Also taken by Dr. L. Stejneger 
and Dr. C. \V. Richmond at Plantation Catalina, El Yunque, 800 feet altitude, and by L. M. McCormick 
at Caves of Aguas Buenas. Also known from Santa Cruz Island. 
This is probably the only species of the family occurring in Porto Rico, although Gundlach states 
that his specimens of Epilobocera were labeled “ E. cubensis” by von Martens. 
Local name Buragina; Buruquena (Gundlach). 
Family PILUMNM Leach, i8ii). 
XANTHIDdJ Alcock, i8q8. 
Carapace commonly transverse and convex, with the antero-lateral margins arcuate, and armed 
with several lobes, teeth, or spines. The front is of moderate width, in general not projecting over the 
first antennae and the bases of the second, the latter being seldom excluded from the inner hiatus of 
the orbits. 
