Table 1 (Continued) 



The data in Table 1 support Becker's conclusions in part. The numbers of anal rays and 

 AO photophores increase slightly from south to north, but the reverse is true for pectoral rays 

 and gill rakers. The greatest variation among the four areas of the eastern Pacific is in the 

 numbers of gill rakers. There is an average difference of 2 total rakers between the northern 

 and southern extremes of the total range, with both the upper and lower counts contributing to 

 the difference. 



Protomyctophum (Hierops) beckeri 



Wisner, 1971 



Fig. 10— Protomyctophum (H.I beckeri, female, 36.4 mm. 



Description 



D. 11-12; A. 21-23; P. 14-15: AO 14 (13-15); gill rakers 4 + 1 -I- 13 (12-14), total 18 (17-19); 

 vertebrae 37 (4 specimens). 



P. (H.J beckeri is superficially very similar to P. (H.l crockeri and P. (H.) chilense in 

 having similar arrangements of photophores and precaudal luminous glands. It differs princi- 

 pally in having fewer total gill rakers (16-18) than the other two species (20-23) (Table 2). The 

 relationships of these three species are discussed following the account of P. (H.) chilense. 



Size: To about 37 mm. 



Least depth of capture: To 326 m at night, near Hawaii. Becker ( 1963b) reported the 

 capture of one specimen at the surface at night in the central tropical Pacific. 



Distribution: Known only from the five localities indicated by solid triangles in Fig. 9. 



22 



