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BULLETIN 2 01, UNITED STATES NATIONAL MUSEUM 



rocco, 1,590 meters (Hansen) ; off South Africa, 500 fathoms (Tatter- 

 sall) ; Gulf of Aden, 1,270 meters (Tattersall) ; Gulf of Panama, 700 

 fathoms (Faxon) ; off Hawaii, 762 to 1,000 fathoms (Ortmann). The 

 present material comes from the Caribbean Sea, from off the coasts of 

 California, and from the Bering Sea. The latter record extends the 

 geographical range of the species very considerably. The species is 

 bathypelagic rather than bottom living, and most of the specimens 

 already recorded were taken in nets and trawls working in deep water 

 but above the bottom. Younger specimens are, as a rule, found in lesser 

 depths than older ones. 



Figure 3. — Petalophthalmus armiger Willemoes-Suhm: a, Lateral view of anterior end to 

 show carapace, rostrum, eye, antennule, antennal scale, and mandibular palp; b, dorsal 

 view of anterior end to show rostral plate, eyes, and antennal scale; c, telson and uropods. 



Remarks. — These five specimens came from three widely separated 

 geographical regions — the Caribbean Sea, off the coast of California, 

 and the Bering Sea — yet I can find no valid differences between the 

 specimens which could be regarded as of specific value, unless it be in 

 the pleopods, to be discussed later. I regard all the specimens as 

 belonging to one species, the genotype. 



