PART 1 garth: pacific oxyrhyncha 161 



Breeding: Ovigerous females were encountered by the Albatross off 

 Oregon in April, off Kamchatka (extralimital) in June, and in the 

 Aleutian Islands in August. 



Remarks: It will be noted that our entire knowledge concerning the 

 species is dependent upon the work of the Albatross, since she alone of 

 oceanographic vessels plying northerly waters was equipped to probe the 

 great depths required. The overlap in range between Chionoecetes 

 tanneri and C. angulatus in Oregon and Washington waters suggests 

 again that, as with C. opilio and C. bairdi, we may be dealing with a 

 single polytypic species. In the latter case it is C. opilio that stands as 

 the parent form, giving rise to C. bairdi in the eastern and C. o. 

 elongatus in the western Pacific. In the former case it is C. angulatus 

 that bridges the Aleutian Island gap from British Columbia to Kam- 

 chatka that separates the earlier named C. tanneri of the eastern Pacific 

 from C. japonicus of the western. 



Subfamily OPHTHALMIINAE Balss 



Stenocionopinae Miers, 1879c, p. 652. 

 Stenocionopoida Alcock, 1895, pp. 161, 166. 



O phthalmiinae Balss, 1929, p. 6 [Name substituted for Stenociono- 

 pinae Miers to conform with substitution of Ophthalmias for 

 Stenocionops (Rathbun, 1897, p. 157)]. 

 The orbit consists, if complete, of a supraocular eave and a postocular 

 spine, while the intercalated spine is lacking . . . Longer spinous out- 

 growths on the supraocular eave and on the postocular spine are for the 

 most part present. The shape of the body is elongate, somewhat truncate 

 in front, often provided behind with a median spine or outgrowth. 

 (Balss) 



Key to the New World Genera of the 

 Subfamily O phthalmiinae 



(Pacific genera are shown in bold-face type and are treated in this 



volume.) 

 la. Eyes furnished with orbits completely enclosed, and often out- 

 standing and tubular 

 2a. Orbits not projecting beyond general outline of carapace. 



Thersandrus 



2b. Orbits projecting beyond general outline of carapace, and 

 often tubular 



