PART 1 garth: pacific oxyrhyncha 431 



Description: Panama specimens differ from more northern ones in 

 the above characters chiefly. However, the obsolescence of the outer row 

 of excavations on the arm is not altogether constant. The old male in 

 Thoe panamensis has widely gaping fingers, as in T. sulcata, but the 

 tooth on the dactyl at the middle of the gape is broader than long, its 

 edges tridentate or tricrenulate. On the merus of the legs no spines or 

 spinules show among the marginal hairs, nor is there a spine on the 

 posterior surface near its proximal end. (Rathbun, 1925) 



For a further discussion of variable characters see Remarks below. 



Materia! examined: 79 specimens from 22 stations. (See Table 92) 

 From Salinas Bay, Costa Rica, to Salinas, Ecuador. 



Measurements: Largest specimen, male: length 14.2 mm, width 12.6 

 mm, rostrum 1.5 mm, width 1.6 mm, cheliped 18.2 mm, chela 9.0 mm, 

 dactyl 4.7 mm, height of palm 3.6 mm, of gape 1.0 mm, ambulatory legs 

 15.3, 12.6, 11.5, and 10.0 mm, respectively. Female specimen: length 

 10.8 mm, width 9.4 mm. 



Color in life: Basic color dull yellowish brown, except for manus of 

 chelipeds, which is pinkish, and the dactyls which range from deep rose 

 to bright orange, shading distally to white. All underparts white. Females 

 usually more brown, less yellow, than males ; young paler yellow than 

 adults, with manus violet, not pink ; chelae even at this stage bright 

 orange. (Crane, of Costa Rican specimens) 



Habitat: Found at extreme low-tide levels, in tidepools, and in 

 Pocillopora coral. Usually well decorated with the shells of Spirorbis- 

 like polychaetes, bryozoans, and other growths. (Crane) Hancock expe- 

 ditions specimens had serpulids, bryozoans, and hydroids. 



Depth: Shore to 2.5 fathoms. 



Size and sex: Males are from 4.8 to 14.2 mm, females from 7.2 to 

 11.4 mm, the latter figures applying to ovigerous females as well. 



Breeding: Ovigerous females were encountered by the Velero III in 

 Costa Rica in February, and in Panama and Colombia in January and 

 February. 



Remarks: The following are characters previously used for differen- 

 tiating Thoe panamensis from T. sulcata, together with evidence con- 

 cerning their geographic variability: 



1. Spinulation of the legs: Here the Velero III series shows complete 

 intergradation from sharp spines to no spines at all. The former condi- 

 tion, typical of Thoe sulcata sulcata, is found in specimens from the Gulf 

 of California, specimens from as far north as Tiburon and Angel de la 

 Guarda Islands exhibiting this feature to no greater advantage than 



