420 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 

 EURYPANOPEUS PLANUS (Smith) 



Plate 175, Figures 3-5 



Panopcus planus Smith, Proc. Boston Soc. Nat. Hist., vol. 12, 1869, p. 283 (type- 

 locality. Bay of Panama; cotypes in P. M. Y. U.). — Benedict and Rathbun, 

 Proc. U. S. Nat. Mus., vol. 14, 1891, p. 369, pi. 24, figs. 10 and 11. 



Eurypanopeus planus A. Milne Edwards, Crust. R6g. Mex., 1880, p. 321, pi. 59, 

 fig. 4-4c. 



Diagnosis. — Carapace depressed, rugose. Lateral teeth truncate 

 (save the last), well separated. Front prominent. Chelipeds heavy, 

 carpus nearly smooth, fingers gaping, color of immovable finger con- 

 tinued on palm. 



Description. — Carapace slightly convex in an antero-posterior 

 direction, in general depressed; anterior and antero-lateral portion 



roughly granulate and rugose; posterior and 

 middle portion nearly smooth, punctate; 

 gastric and hepatic regions well delimited. 

 Front produced, a narrow median V cut, 

 lobes deeply sinuous forming a pronounced 

 outer lobule. Two closed supraorbital fis- 

 FiGTjRE 67.-EUEYPANOPEUS ^urcs dccply imprcsscd ; outcr sluus broad and 

 PLANUS, Bay of Panama, shallow. Lateral cmargiuations V-shaped, 



CARAPACE, ENLARGED. AFTER i.' J 1_ r> 



BENEDICT AND rathbun coutmucd by a groove on carapace. Coa- 



lesced tooth (first and second) also third and 

 fourth sub truncate; orbital angle a little more than a right angle; 

 other angles obtuse, rounded; fifth tooth triangular, tip blunt. 



Chelipeds heavy; carpus lacking groove, or with a faint one, inner 

 tooth slightly marked, scarcely dentiform; palms higher than superior 

 length in the full grown; lower margin of manus convex, upper margin 

 also convex, but highest at base of dactylus; propodal finger high at 

 base, lower margin sinuous, tip curved upward, color continued well 

 back on palm; dactylus slender, arched, a large backward-pointing 

 basal tooth in major chela. 



Color. — Ranges from indigo blue and slate, really more slate color, 

 to sepia and seal brown; all are variously mottled with lighter speckles 

 of pearl blu ■ or olive buff as crabs are bluish or brownish. In blue 

 backed crabs the lower half of outer face of chela is purplish or between 

 a hyacinth blue and royal purple tinge; in brown or drab crabs this 

 part of the chela is porcelain white with a china-blue tinge. A small 

 specimen, 10.3 mm. wide, is mottled porcelain white, ochraceous and 

 mummy brown, legs speckled with wood brown; major hand porcelain 

 white, fingers black or clove brown except extreme tips; minor hand 

 black or clove brown speckled giving it a grayish color, speckles most 

 numerous toward upper margin. (Schmitt.) 



Measurements. — Male (44188), length of carapace 17.3, width of 

 same 27.3, fronto-orbital width 12.8, width of front 7.1 mm. 



