202 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 105 



mens), UMMZ 142823 and 164783 (2 specimens), USNM 38829, 

 57595, 71273, 148777, 148778, 151797 (totaling 7 specimens), CNHM 

 55422 (3 specimens), AMNH 1963 (1 specimen), BM 1880.5.1.3 

 (holotype, Polymixia japonica Giinther, Inoshima, Japan; Challenger 

 Expedition); Philippine Islands (14 specimens), USNM 98857-98861 

 (13 specimens, collected by Albatross Expedition at Capitancillo 

 Island and Tagola Point Light; Hawaii, USNM 51607 (holotype, 

 Polymixia berndti Gilbert, Honolulu). 



Description: Soft dorsal fin rays 31.2: 29-35; dorsal spines V or VI; 

 total number of gill rakers 13.1: 12-14; soft anal rays 15.3: 14-17; 

 pectoral rays 15.9: 15-17; lateral line pores 32.2: 29-34. A com- 

 parison of the length of head, barbel, pectoral fin, upper jaw, diameter 

 of orbit, and vertical scale rows among two Pacific populations is 

 given in tables 4 and 6. 



Specimens from Japan and Hawaii with a large black spot or 

 blotch on outer third of longest rays of dorsal fin in the area of the 

 first six rays. This conspicuous black spot dusky in Philippine speci- 

 mens, not nearly as evident as in specimens from Japan. This differ- 

 ence may be due to the poor condition and preservation of the Philip- 

 pine specimens and not a population divergence, for all specimens 

 had frayed fins. Anal and caudal fins pale or with some dusky, 

 particularly on the margin of the caudal; pectoral fin pale; pelvic 

 pale with some whitish on edge of outer rays. Coloration of head 

 and body as in Atlantic forms. 



Giinther (1887) reported on specimens from Japan, but his illus- 

 tration, plate 1, figure b, probably represents nobilis because the 

 dorsal fin has 36 soft rays. Steindachner and Doderlein (1883), no 

 doubt, inadvertently omitted the barbels from their plate 4, figure 2. 



Geographic distribution: Japan, Philippines, and Hawaiian 

 Islands. Polymixia has been reported from the Andaman Sea (Al- 

 cock, 1889, p. 381 and 1891, p. 23) and Natal, East Africa (Barnard, 

 1925, p. 359; Smith, 1949, p. 149), but I am unable to determine what 

 form is represented in these areas since the reported descriptions are 

 incomplete and no specimens were available for my examination. 



Discussion: The differentiation of Polymixia in the Pacific area is 

 not as clear cut compared with the Atlantic forms, but I allocate the 

 rank of species to japonica owing to the nature and measure of strong 

 divergence among the three forms. 



P. japonica has differentiated considerably, although incompletely, 

 in certain meristic characters, but in varying proportions from lowei 

 and nobilis. It occupies an intermediate position in a comparison 

 of frequency distributions of the most critical meristic characters, the 

 number of dorsal fin rays and the total n amber of gill rakers (tables 



