No. 10 GARTH : BRACHYURAN FAUNA OF THE GALAPAGOS 395 



800-38. Cartago Bay, Albemarle Island, shore, Jan. 22, 1938, 7 males, 



3 females (2 ovig.), 1 young. 

 803-38. Black Beach, Charles Island, shore, Jan. 23, 1938, 2 young. 

 804-38. Onslow Island, off Charles Island, coral, Jan. 23, 1938, 1 

 female. 



-38. Academy Bay, Indefatigable Island, shore, Jan. 25, 1938, 1 

 male, Karl Kiibler, collector. 

 Measurements. — Largest male: length 30.1 mm, width 38.2 mm, 

 cheliped 57.0 mm, chela 30.9 mm, dactyl 18.6 mm, height of gape 3.6 mm. 

 Color in life. — Uniform purplish brown. Hairs on legs and about 

 antennae yellow, in sunlight yellow green. (Garth) 

 Habitat. — Shore, both in coral and under rocks. 

 Depth. — Although predominately a shore species, M. nodosus has 

 been recorded to 12 fms. 



Remarks. — M. nodosus was collected at a greater number of stations 

 than any other species excepting Teleophrys cristulipes Stimpson. It is the 

 most abundant spider crab in the Galapagos Islands, being taken both in 

 coral and in ordinary rock turning at low tide. In the Pocillopora coral 

 colony it occupies an analogous situation to M. (Mithraculus) areolata 

 Lockington of the Bay of Panama, both in relative abundance and as the 

 sole representative of its subgenus. From the experience of the Allan 

 Hancock Expeditions, M. nodosus may be considered a true Galapagos 

 endemic species, none having been encountered on the mainland coast as 

 far south as the bays of San Juan and San Nicolas, Peru, well within the 

 limits of the Chilean fauna. 



Mithrax (Mithraculus) denticulatus Bell 



Mithrax denticulatus Bell, Proc. Zool. Soc. London, vol. 3, p. 172, 1835; 



Trans. Zool. Soc. London, vol. 2, p. 54, pi. 11, fig. 2, 1836. 

 Mithrax (Mithraculus) denticulatus Rathbun, Bull. 129, U.S. Nat. 

 Mus., p. 428, pi. 154, figs. 2-3, and synonymy, 1925. 



Type locality. — Galapagos Islands, under stones. 



Type. — Not extant. 



Range. — From Cape San Lucas, Lower California (Xantus), to 

 Ecuador (Nobili) ; Galapagos Islands (Bell). 



Atlantic analogue. — M. (Mithraculus) coryphe (Herbst). 



Diagnosis. — Carapace wide, breadth exceeding length by nearly one 

 half. Two acute tubercles and a spine on lateral m.argin, the latter 

 opposite greatest width of carapace. Inner margin of carpus laminate. 



Material examined. — None from the Galapagos Islands. The Han- 

 cock collections contain a long series of this species ranging from Espiritu 

 Santo Island, Gulf of California, to Manta, Ecuador. 



