to be an artifact and thus, along with the concomitant narrowed interorbit bones, offers 

 justification for retaining Hierops as a subgenus of Protomyctophum . 



Protomyctophum (Hierops) crockeri 



(Bolin, 1939) 



Fig. 8 — Protomyctophum (H.) crockeri. male, 34.5 mm. (Photophores retouched). 



Description 



D. 11-13; A. 21-22 (19-24); P. 15-16 (13-17); AO 13-14 (12-16); gill rakers 4-5 (6) -F- 1 -H 15 

 ( 13-17 ), total 20-22 ( 18-24) (see Table 1 ); vertebrae 36-37. 



Three (rarely 4) SAO, usually equally spaced and in a straight, or nearly so, flatly oblique 

 line; SAO, usually over or just before VO4, rarely over midpoint of VO.^.j interspace. Interorbi- 

 tal width usually half or less than width of expanded end of upper jaw. 



Supracaudal luminous glands of males ( Fig. 3 ) begin to appear on specimens of about 25 

 mm and are single, prominent glands that protrude well above the dorsal profile of the caudal 

 peduncle, just before the procurrent caudal rays, and extend somewhat down along the lateral 

 surface of the peduncle. Infracaudal glands of females with 3 (rarely 2 or 4) small, oblong, 

 juxtaposed spots embedded in the caudal peduncle. 



Size: To about 46 mm. 



Least depth of capture: Commonly taken at night above 100 m but apparently not at the 

 surface; find no record of capture by surface nets. 



Distribution: Across the North Pacific, primarily within the sub-arctic and California 

 Current systems, to about 25° N (rarely beyond) (Fig. 9). At the seaward edge of these currents 

 the species apparently occurs in the transition zone of the North-Central Water. The capture 

 localities include those from Aron (1960), Becker (1963b), and Berry and Perkins (1966) and 

 from many trawls by Scripps vessels. Only a relatively small part of these collections was 

 immediately available for study. 



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