24 
BULLETIN CF THE UNITED STATES FISH COMMISSION. 
Key to /he Porto Rican genera of the family Pihimnidee. 
A. The ridges that define the efferent branchial channels, if present, are usually low and are confined to the 
posterior part of endostome, never reaching to anterior boundary of buccal cavern. 
B. Fronto-orbital border less than half the greatest width of carapace. 
('. Antero lateral borders of carapace sharp, crest-like; upper border at least of arms, and of fourth, fifth, 
and sixth segments of legs sharp and crest-like Platypodia. 
O'. Antero-lateral borders of carapace and upper borders of legs not crest-like. 
D. Antero-lateral borders entire up to a strong lateral epibranchial tooth _ Carpihun 
O'. Antero-lateral borders divided into lobes or teeth. 
E. Carapace usually conspicuously lobulate, granulate, and hairy, chelipeds and legs also granulate and hairy. 
Act'd! a 
E'. Carapace, chelipeds, and legs not sharply granulate and hairy. 
F. Fingers sharp-pointed, not hollowed Cydoxanthops 
F'. Fingers blunt-pointed, hollowed at tip Xanthodius 
B'. Fronto-orbital border half or more than half the greatest width of the carapace. (True of American 
species of Liomera). 
C. Carapace transversely oval. 
I). Ambulatory legs with upper margins spiny or roughly granular Xavthias 
I)'. Ambulatory legs with upper margins smooth or nearly so. 
E. Antero-lateral teeth strong, greatly projecting. Carapace deeply areolated Leptodius 
E'. Antero-lateral teeth small, little projecting. Carapace slightly or not at all areolated. 
F. Carapace crossed by transverse, broken, granulated lines Eiirypcmopeus 
F'. Carapace without transverse granulated lines. 
G. Three suture lines near the outer angle of the orbit. Fingers somewhat hollowed at tip Liomera 
G'. No suture lines near the outer angle of the orbit. Fingers acute, not hollowed at tip Eucratodes 
O'. Carapace more or less hexagonal, or subquadrate. 
I). Ambulatory legs spinulous. 
E. Antero-lateral margin cut into five teeth or lobes, including the outer orbital Chtorodidta 
E'. Antero-lateral margin with second and fifth normal spine or tooth reduced or wanting Micropanopc 
1)'. Ambulatory legs not spinulous. 
E. Large cheliped very broad and heavy, more or less cristate above . Olyptoplax 
E'. Chelipeds of moderate size. 
F. Front very narrow and advanced. Postero-lateral margins strongly converging. Carapace hexagonal. 
Hexapanopen* 
F'. Front of moderate width. Postero-lateral margins not strongly converging. Carapace subquadrate. 
Enpanoprur 
A'. The ridges that define the efferent branchial channels extend to anterior boundary of buccal cavern and 
are often very strong. 
B. Fronto-orbital border just about half or less than half greatest breadth of carapace, which is broad 
and transversely oval. 
C. The basal antennal joint does not nearly reach the front Menippe 
O'. The basal antennal joint reaches the front. 
D. Anterior margin of merus of outer maxillipeds notched at orifice of efferent branchial channel Ozius 
D'. Anterior margin of merus of outer maxillipeds not notched Eurylium 
B'. Fronto-orbital border much more than half greatest breadth of carapace. 
C. Merus of external maxillipeds as long as or longer than broad. 
D. Fronto-orbital border about two-thirds greatest breadth of carapace Pilumnus 
IP. Fronto-orbital border much more than two-thirds greatest breadth of carapace. 
E. Basal antennal joint as broad as long; arm scarcely projecting beyond lateral border of carapace Eriphia 
E'. Basal antennal joint longer than broad; at least half of arm projects beyond carapace Melybia 
C'. Merus of external maxillipeds about twice as broad as long Domecia 
Genus CARPILIUS Leach. 
Caipilius Leach in Desmarest, Diet. Sci. Nat,, xxvm, 228, 1823. 
Carapace broad, very convex in both directions, smooth (except for some coarse pitting inside 
the frontal and antero-lateral border), with no indication of regions; its antero-lateral borders strongly- 
arched, thick, entire, smoothly molded; its postero-lateral borders strongly convergent, straight, with 
a prominent tubercle at angle of junction with antero-lateral. Front moderately broad (less than a 
third the greatest width of carapace), deflexed, three-lobed, the middle lobe prominent, the edges of 
all thickened. Orbital margins entire, the upper margin thickened and forming a well-marked blunt 
tooth at its junction with the antero-lateral margin. Eyes on short, thick stalks. Antennules folding 
obliquely; inter-antennulary septum broad. Basal joint of antennse long, flat, running up into an 
oblique cleft between margin of front and infra-orbital plate; antennary flagellum very small, less than 
half diameter of orbit and lodged in said cleft, Merus of external maxillipeds with its anterior border 
very oblique. Chelipeds massive, smooth, unequal in both sexes; lingers bluntly pointed, those of 
