THE BRACHYURA A HD MACRURA OF PORTO RICO. 
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upper margin. Outer surface of merus and inner margin of carpus granulate. Otherwise the cheli- 
peds are smooth and unarmed. Propodal and terminal joints of ambulatory legs spinous. 
Dimensions of male: Length, 10 mm. ; anterior width, 8.6 mm. ; posterior width, 12.2 mm. ; width 
of front below, 4.5 mm. 
Florida; Bahamas; West Indies; Sabanilla, United States of Colombia; Brazil; Bermudas. Porto 
Rico: Beach at San Juan; reefs at Ponce; Ensenada Honda, Culebra; Hucares. 
Genus PLAGUSIA Latreille. 
PUajusia Latreitle, Gun. Crust., i, 33, 1806. 
Carapace much flattened and with numerous tubercles. Antennules exposed in deep longitudinal 
sinuses of the front and visible in a dorsal view. Outer maxillipeds with merus joint well developed, 
as wide as ischium. Merus joints of ambulatory legs spined near distal end. Male genital appendage- 
of first pair without a terminal claw. 
Plagusia depressa (Fabricius). 
Cancer depresms Fabricius, Sys. Ent., 406, 1775. 
Flag us ia depress us Say, Jour. Phils . Acad. Sei., I, 100, 1817. 
Carapace broader than long; surface covered with depressed tubercles margined with short sehe. 
A series of about six prominent acute tubercles arranged in an arc across front of gastric region. Lateral 
margins three-spined behind orbit. Frontal margin tuberculate between antennules, with two blunt 
teeth between antennule and orbit. Outer orbital spine strong. Terminal segment of the abdomen in 
male with sides distinctly convergent. Chelipeds with tuberculate crests above, fringed with setae. 
The lobe above the bases of the second and third ambulatory legs broad and regularly dentate. 
Male: Length, 38 mm.; width, 39.5 mm.; width between outer orbital angles, 24 mm. 
Known from Charleston, 8. C., to Brazil; from the Mediterranean to St. Helena and South Africa; 
Bermudas (Verrill). Porto Rico: Arroyo (Fish Hawk)-, San Juan (Gundlach). 
Genus PERCNON Gistel. 
Acanthopv s de Haan, Fauna Japon., 5, 1833; 29, 1835. (Name preoccupied.) 
Percnon Gistel, Naturg. Thierreichs, p. vm, 1848. 
Lcialophus Miers, Cat. Crust. New Zealand, 46, 1876. 
Carapace remarkably flattened, with smooth naked ridges on its upper surface, but without 
numerous tubercles. Antennules exposed in deep longitudinal sinuses of the front and visible in a 
dorsal view. Outer maxillipeds with merus joint very small and much narrower than preceding joint. 
Merus joints of ambulatory legs with a series of spines on their upper margins. Male genital append- 
ages of the first pair not twisted, with a terminal hook. 
Percnon planissimum (Herbst). 
Can ci i ■ planissimus Herbst, Natur. Krabben n. Krebse, nr, pt. 4, p. 3, pi. lix, f. 3, 1804. 
Leiolophus planissimus Miers, Cat. Crust. New Zealand, p. 46,1876. 
Percnon planissimum Rathbun, Proc. D. S. Nat. Mus.,xxn,281, 1900. 
Carapace suborbicular, longer than broad, antero-lateral margin with three teeth besides the 
orbital. Front with four spines between antennules, three spines between antennule and orbit. 
Merus and carpus of chelipeds spinous. Hands in male strong; palms compressed and considerably 
dilated, much broader than the wrist, not sulcated on upper margins. Greatest width of abdomen of 
male exceeding its length to base of last segment. Ambulatory legs with transverse bands of color. 
Male: Length, 22 mm.; width, 20 mm.; width between outer orbital angles, 13.7 mm. 
Plava de Ponce Reef, Porto Rico. Distributed throughout the West Indian region to Brazil; 
Bermudas (Verrill); Azores; west coast of Spain and Portugal; west and south Africa; Oriental 
region from Mauritius to Japan, and Sandwich Islands; Clarion Island, Mexico; Cape St. Lucas; Chile. 
