THE BRACHYURA AND MACRURA OF PORTO RICO. 
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Genus PINNIXA White. 
1‘fnnixa White, Ann. Mag. Nat. Hist., xvm, 177,1846. 
Carapace much wider than long; integument usually firm. Front narrow, nearly transverse. 
Orbits broadly ovate or nearly circular, with a wide inner hiatus which is partly occupied by the basal 
antennal joints. Antennules transversely or obliquely plicated in wide fossettes which communicate 
with each other beneath the front. Eye-stalks very short. Epistome linear-transverse. Ischium of 
maxillipeds small, merus large, distal portion of outer margin convex; palp joined to summit of merus; 
third joint articulated on inner side of the preceding one near base. Chelipeds of moderate size; merus 
trigonous; carpus smooth; hand large, compressed. Second ambulatory legs larger than first; third 
pair largest of all; fourth pair much shorter than third and relatively stouter than first and second. 
Abdomen in both sexes 7-jointed and narrower at base than the width of last sternal segment. 
Pinnixa minuta, sp. nov. 
Carapace of male less than twice as wide as long; a line connecting the lateral angles is behind 
the gastro-cardiac suture; The middle portions of the lateral margins are subparallel to each other. 
The regions are separated by deep furrows, the gastric, cardiac, and branchial regions being separately 
convex; the cardiac region is less than twice as wide as long and without a crest; upper surface finely 
granulate, the antero-, lateral margins coarsely granulate. Front truncate and non-projecting. Antenna; 
longer than the width of front. Merus of the maxillipeds longitudinal; propodus of palpus about 
1.5 times as long as wide; dactylus spatulate. Chelipeds granulate; palm stout, 1.5 times as long as 
wide; the fingers are two-thirds as long as the palni and gape slightly. The ambulatory legs are 
ambulatory leg, x 13.33. (d) Last three abdominal segments, x 13.33. 
margined with broad bands of spinuliform granules; first two pairs narrow, with very slender dactyls; 
third pair much larger, but similar; fourth pair the narrowest and slightly overreaches merus of 
third pair; its dactylus is shorter and relatively stouter. Sternum granulate along margins of seg- 
ments. Abdomen oblong, with sixth and seventh segments narrowest; sixth shorter than third, 
fourth, or fifth, which are subequal; seventh transversely oblong, its distal margin gently arcuate. 
The surface shows a few granules. Surface of carapace, chelipeds, and legs pubescent. 
Dimensions of male: Length, 1.3 mm.; width, 2 3 mm. 
Type locality, Mayaguez Harbor, 161 to 172 fathoms, station 6066; one male (Cat. No. 23768). 
Genus DISSODACTYLUS Smith 
Dissoclactylus Smith, Trans. Conn. Acad. Sci., ii, 172, 1870. 
KrMnopliilus Rathbun, Amer. Nat., xxxiv, 590, 1900 
Carapace broader than long, pentagonal, broad behind, broadest at antero-lateral angles; surface 
smooth, not areolated; front narrow, horizontal, its margin continuous with arcuate antero-lateral 
margins. Eyes minute? superior margin of orbit slightly or not at all emarginate. Antennules trans- 
verse. Epistome usually very short, so that the labial border approaches A'ery near to front, leaving 
only a narrow space, which is nearly filled by the antennal*. The labial border is not interrupted in 
the middle by any projection or emargination and is continuous with lateral margin of buccal area. 
Palate without longitudinal ridges. Ischium and merus of maxillipeds coaleseent; palpus composed 
