344 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



Genus PARAMITHRAX Milne Edwards 



Paramithrax Milne Edwards, 1834, p. 324 (part: §A). Miers, 1879, 

 p. 655 (part: subgenus Paramithrax, restricted). Rathbun, 1918, 

 p. 17; 1925, p. 338. 



Type: The Australian and New Zealandian Paramithrax peroni 

 Milne Edwards, 1834, by subsequent designation of Miers (1879c, 

 p. 656). 



Description: Carapace oblong-triangular, usually spinous above. 

 Rostrum composed of two spines divergent from their base. Orbits large, 

 deep, oval, with a forward aspect, incomplete below, upper margin promi- 

 nent, with two deep fissures and long spines. The eyes concealed when 

 retracted; stalks rather long, slender, curved, cornea small. Postorbital 

 spine conical, usually remote from orbit . . . Basal article of antenna 

 much enlarged, armed with spines ; movable portion arising within orbital 

 margin and separated from the cavity of the orbit by a narrow process 

 of the basal article. Anterior margin of buccal cavity straight or nearly 

 so. Merus of outer maxillipeds notched at anterointernal angle. Cheli- 

 peds strong; fingers pointed. Ambulatory legs cylindrical; dactyls un- 

 armed. (Rathbun, 1925) 



Abdomen seven-segmented in both sexes. 



Range: Western South Pacific, especially Australia, New Zealand, 

 and outlying islands. Approaches the American continent only at Juan 

 Fernandez Island, Chile. 



Paramithrax baeckstroemi Balss 

 Plate U, Fig. 2 ; Plate 41, Fig. 2 



Paramithrax peroni, Lenz, 1902, p. 756. Not P. peronii Milne Edwards, 

 1834. 



Paramithrax peronii, Rathbun, 1910, p. 573. Not P. peronii Milne Ed- 

 wards, 1834. 



Paramithrax backstromi Balss, 1924, p. 336, text-fig. 3. Rathbun, 1925, 



p. 339, pi. 123, text-fig. 108. 

 Paramithrax baeckstroemi, Garth, 1957, p. 30. 



Type: Male holotype, length 20.8 mm, width without spines 12.8 

 mm, with spines 14 mm. 



Type locality: Masatierra Island, Juan Fernandez Islands; K. 

 Backstrom, collector; type and cotypes in Museum of Natural History, 

 Gothenburg, fide Dr. Karl Lang. 



