192 U.S. NATIONAL MUSEUM BULLETIN 29 2 



Subfamily Plagusiinae 



Genus Plagusia 



78. Plagusia depressa (Fabricius) 



Figures 62r-t, 63 



Cancer depressus Fabricius, 1775, p. 406 [type-locality: "in mari mediterraneo"]. 

 Cancer squamosus Herbst, 1790, p. 260, pi. 20: fig. 113 [type-locality: "Ostindien"]. 

 Grapsus depressus. — Bosc, 1801-02, p. 203. 

 Plagusia depressus. — Say, 1817, p. 100. 



Plagusia sayi De Kay, 1844, p. 16 [type-locality: Gulf Stream]. 

 Plagusia squamosa. — Latreille, 1825a, p. 145. 

 Plagusia gracilis De Saussure, 1858, p. 449 [type-locality: Cuba]. 

 Plagusia depressa. — Eathbun, 1918, p. 332, pi, 101. — Monod, 1956, p. 455, figs. 

 614-617. 



Diagnosis. — Carapace subcircular, about nine-tenths as long in 

 midline as wide, convex longitudinally and especially transversely, 

 sparsely and ii-regularly tuberculate, partially covered with short 

 plumose hairs forming scalelike pattern around tubercles and elsewhere; 

 lateral margins converging strongly anteriorly, armed with three sharp 

 teeth posterior to outer orbital angle, fronto-orbital distance about three- 

 fifths of maximum width of carapace; /ron^ divided into three lobes by 

 very deep notches or slits, exposing antennules even when retracted, 

 median lobe curving sharply ventrally in midline. Eyes comparatively 

 small, cornea slightly narrower than eyestalk. Ventral margin of orbit 

 sharply produced, armed with two large triangular teeth at mesial end, 

 slanting obliquely to anterolateral angle of mouth area. Third maxilli- 

 peds without hairy ridge on inerus, not gaping widely, not exposing 

 mandibles. Chelipeds subequal, carpus armed with triangular tooth 

 on flexor margin; palm with three longitudinal rows oj blunt teeth 

 separated by setose furrows; fingers blunt, spoon tipped or hooflike, 

 spiny rows on palm continued on proximal portion of movable finger. 

 Walking legs somewhat flattened but robust, merus of third pereiopod 

 between two-fifths and one-half as wide as long, with sharp upstand- 

 ing subdistal tooth on extensor margin; dactyl between one-half and 

 three-fifths as long as extensor margin of propodus. Denuded first 

 pleopod of male terminating in posterior view in small triangular 

 chitinous endpicee partially embedded in swollen end of appendage 

 (fig. 62r) . A rather large species, maximum carapace length in midline 

 nearly 60 mm. 



Color in life. — Carapace olive tan with brown to black tubercles 

 and dark brown or black areas dorsally. Mesogastric region largely 

 dark with median olive stripe and with pair of horns extending 

 anterolaterally across protogastric region toward orbits and recurving 

 posterior to them; small dark spot immediately mesial to anterior- 



