Vn of males enlarged, nearly filling space between orbital rim, premaxillary and nasal 

 apparatus, and almost confluent with So. Vn of females much smaller, elongate, not reaching 

 to So. Luminous scale at PLO large, its length equal to or slightly greater than distance 

 between PLO and pectoral origin, the tissue convoluted. 



Teeth of jaws as in Form R-1. Palatines very sparsely toothed except for a patch of small 

 teeth at anterior end, these teeth becoming increasingly larger toward the tip. Vomer heads 

 naked. Mesoptergoids thickly set with small, sharp teeth. 



Size: To 85 mm. 



Least depth of capture: To 360 m at night. 



Distribution: Form R-2 is known only from a narrow region of North Pacific Ocean, about 

 30° to 43° N, 140° W to 170° E. This distribution is very similar to that of Form R-1, and the two 

 have twice been taken sympatrically (Fig. 119). 



Form R-3 of the Diaphus rafinesquii species complex in the 

 North Pacific Ocean 



Description 



D. 13 (12); A. 12-13; P. 11; A0 5(6) + 4 (5), total 9 (10); gill rakers 7-8 -I- 1 + 15-16(14-17); 

 vertebrae 33-34. 



Posterodorsal angle of operculum rounded, not recurved. Dorsal origin on or slightly 

 behind a vertical from pelvic origin. Anal origin behind a vertical from end of dorsal base by a 

 distance equal to about half the length of anal base. Base of adipose fin distinctly behind a 

 vertical from end of anal base. 



PLO usually behind, rarely over, pectoral origin and nearer that origin than to lateral line 

 by about three of its diameters. VLO over bases of inner pelvic rays and about midway 

 between them and lateral line. PLO, VLO, and SAO2 on a straight line. VO...3 interspace 

 about 57% (48-66% ) of space between VLO and VO2. SAO.i, Pol, and upper Pre from one to 

 three of their diameters below lateral line. SAO series moderately angulate, a line through 

 SAO1.2 passing through or slightly before VOr, and well behind SAO;,. First and last AOa 

 elevated by one to two of their diameters above adjacent AOa. Pol variably under middle to 

 anterior end ofbase of adipose fin. Prcj distant from Prcn by a space nearly equal to that 

 between Pre, and Prc.^. 



Vn of males enlarged, undivided, extending from nasal apparatus to and confluent with So 

 in a 94-mm specimen; in a 58-mm specimen the Vn and So are not quite confluent. In smaller 

 males Vn incompletely formed and falling well short of the So. Vn of females elongate and 

 narrow, but no females over 45 mm (based on structure of Vn) were available. Luminous scale 

 at PLO large, about equal in length to distance between PLO and pectoral origin in the largest 

 specimen (94 mm) but about half that length in the 58-mm specimen, the tissue finely convo- 

 luted. 



Teeth of jaws as in Forms R-1 and R-2. Palatines almost naked except for shorter anterior 

 portion bearing enlarged, backward-curving teeth; a few small teeth scattered sparsely along 

 posterior portion of palatines. Vomer heads naked. Mesopterygoids with a few randomly scat- 

 tered sharp teeth. 



136 



