THE SPIDER CRABS OF AMERICA 



355 



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carapace at branchial regions 15.4, 

 width between tips of postocular 

 spines 17 mm. 



Range. — From Bahama Banks and 

 Florida Keys to Bahia, Brazil. Shal- 

 low water to 60 fathoms. 



Material examined. — See table, 

 page 355. 



Genus PITHO Bell 

 Pitho Bell, Proc. Zool. Soc. London, vol. 

 3, 1835 (Feb. 24, 1836), p. 172; type, 

 P. sexdentata Bell. 

 Othonia Bell, Trans. Zool. Soc. London, 

 vol. 2, 1836, p. 55; type, 0. sexdentata 

 (Bell) . Name preoccupied by Johnston, 

 in Loudon's Mag. Nat. Hist., vol. 8, 

 March, 1835, p. 181, for a genus of 

 worms. 

 Piloronus Gistel, Natur. Thierreichs, 

 1848, p. X. (Substituted for Pitho 

 Bell, said to be preoccupied by Pytho 

 Fabricius). 

 Engyzomaria Gistel, Natur. Thierreichs, 

 1848, p. X. (Substituted for Othonia, 

 preoccupied) . 

 Microrynchus Desbonne, in Desbonne 

 and Schramm, Crust. Guadeloupe, 1867, 

 p. 20; type, M. Iherminieri Desbonne. 



Carapace truncate in front; frontal 

 region wide; rostrum very short, 

 formed of two small teeth. Orbits 

 small, tubular, deep, and directed 

 forward; eyes slender. Outer anten- 

 nae short; basal article lamellose, 

 forming floor of orbit; next article 

 flat, short, and broad, outwardly ex- 

 panded; third article flat, but smaller; 

 flagellum very small. Carapace ob- 

 long-oval, antero-lateral and postero- 

 lateral borders forming together an 

 arcuate line. Merus of outer maxil- 

 lipeds dilated outwardly and very 

 slightly notched on inner side for in- 

 sertion of palpus. Chelipeds with 

 fingers spoon-shaped; hands more or 

 less compressed. Ambulatory legs 

 stout and rather short; dactyli sharp, 

 spinulous below. Abdomen of male 



