430 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



tends to support, rather than refute, the conspecificity of the two forms, 

 all stages of intergradation between them having been found. It is fur- 

 ther believed that the single character on which Crane based her reten- 

 tion of T. panamensis as a subspecies, namely, the subterminal spur 

 visible on the male first pleopod of specimens from Nicaragua south, but 

 not on specimens from Guerrero north, may itself be subject to geo- 

 graphical variation. If this be true, a perfect cline would exist and T. 

 panamensis might well be relegated to complete synonymy. Its retention 

 here is largely a matter of convenience, the gap between the two series 

 being more apparent than real, and reflecting either the lack of collec- 

 tions from Chiapas and Guatemala, or the absence of rocky shore and 

 colonies of Pocillopora coral from this region. 



Thoe sulcata panamensis Nobili 

 Plate Y, Fig. 9; Plate 47, Fig. 4 



Thoe erosa, A. Milne Edwards, 1875, pi. 19, figs. 4-4d ; 1878, p. 121 



(not synonymy). Rathbun, 1907, p. 74. (Not T. erosa Bell) 

 Thoe edentata, Cano, 1889, pp. 101, 183. (Not Platypes edentata 



Lockington) 

 Thoe panamensis Nobili, 1901, p. 30. Rathbun, 1910, pp. 575, 618 



(part: not the Ecuadorean locality) ; 1925, p. 351, pi. 125, figs. 



5, 6, text-fig. 113. Finnegan, 1931, p. 624. 

 Thoe sulcata panamensis, Crane, 1947, p. 71, text-fig. 2A. Garth, 1948, 



p. 28. 



Type: 1 male, length 10 mm, width 8.5 mm, and 1 female, cotypes, 

 in Turin Museum. 



Type locality: Flamenco Island, Bay of Panama; Enrico Festa, 

 collector. 



Localities subsequently reported, with collectors: Nicaragua: Corinto, 

 Zaca (Crane). Costa Rica: Port Parker, Port [Puerto] Culebra, Piedra 

 Blanca, Jasper Island, Gulf of Nicoya, and Uvita, Zaca (Crane). 

 Panama: Bahia Honda, Zaca (Crane) ; "Panama," Dr. Sternberg, A. 

 Agassiz; Taboga Island, J. Zetek (Rathbun, 1925) ; Taboguilla Island 

 and Perico Island, Albatross (Rathbun, 1907) ; Pearl [Perlas] Islands, 

 Vet tor Pisani (Cano, 1889). Colombia: Humboldt Bay, Askoy (Garth) ; 

 Gorgona Island, St. George (Finnegan), Askoy (Garth). 

 Atlantic analogue: Thoe puella Stimpson. 



Diagnosis: Merus of chelipeds with outer row of excavations tend- 

 ing to become obsolete; spines of anterior margin of meri of walking 

 legs reduced to granules or wanting. Large tooth in gape of manus of 

 chelipeds tridentate. Male first pleopod with a subterminal spur. 



