PART 1 GARTH : PACIFIC OXYRHYNCHA 427 



not excavated or serrated, but with a single tubercle near the middle of 

 the moveable finger: [walking legs] flattened above, longitudinally 

 rugose, the sides furnished with rather long hairs. 



Abdomen in both sexes seven-segmented. In the male, the third to 

 the sixth segments scarcely broader than the first and second. (Bell, 

 modernized terminology) 



Measurements: Type specimen, length 6 lines (13.5 mm), width 

 5 lines (11.3 mm). (Bell) Santa Elena Bay male: length 10 mm, width 

 8.75 mm. (Nobili) 



Color: Light yellowish brown above, paler beneath. (Bell) 



Habitat: Sandy mud. 



Depth: 7 fathoms. 



Remarks: While the writer has not seen Nobili's Santa Elena Bay 

 specimens, a specimen of Schmitt's from Salinas, Ecuador, on Santa 

 Elena Bay, is unhesitatingly placed as Thoe sulcata panamensis. It would 

 appear to follow, then, that the Nobili specimens are also referable to 

 that species and subspecies. This leaves only the question of whether 

 Bell's Thoe erosa should be retained for a hypothetical Galapagos en- 

 demic species having (1) a bicuspid tooth on the dactyl, (2) a double 

 row of deep excavations on the merus of the cheliped, and (3) but one 

 anterior tooth or lobe on the basal antennal article. From the discussion 

 on geographic variability under T. sulcata panamensis (which see) it is 

 apparent ( 1 ) that mature males from the Bay of Panama show the 

 bicuspid tooth, (2) that, while the double row of deep excavations is 

 usually associated with mature males of T. s. sulcata, well developed pits 

 are found in males from isolated populations as far south as Nicaragua, 

 and (3) in the opinion of the writer, the accuracy of Bell's drawings is 

 not such that the absence of a second tooth or lobe on the basal article 

 of the antenna can be depended upon. In the continued absence of 

 specimens of Thoe from the Galapagos Islands, it becomes increasingly 

 apparent that Cuming's T. erosa may have been taken somewhere in the 

 Bay of Panama, perhaps at Santa Elena Bay, in which event Bell's 

 name, rather than Stimpson's or Nobili's, would be applicable to the 

 mainland species. 



Thoe sulcata sulcata Stimpson 

 Plate Y, Fig. 8 ; Plate 47, Fig. 3 



Thoe sulcata Stimpson, 1860b, p. 177. A. Milne Edwards, 1875, pi. 19, 

 figs. 5-5e; 1878, p. 121. Streets and Kingsley, 1877, p. 104. Rath- 

 bun, 1910, p. 575 (part: not the Panama Bay locality) ; 1923b, p. 



