AET. 10 NOTES ON MYCTOPHINE FISHES PARR 39 



separate supraorbital organ followed by a complete fusion of the 

 upper and lower antorbitals on each side. Division IX then differs 

 from the group treated in the key on page 37 (Division VI, Parr, 

 1928) by this latter feature, while the upper and lower antorbitals 

 in the latter group, now under consideration, always remain distinct 

 from each other. 



The upper antorbitals of D. chrysorhynohus are quite large and 

 only narrowly separated from each other as shown in the figure 17. 

 The lower antorbital has a long, narrow, posterior ventral extension 

 along the lower margin of the eye, ending approximately at the 

 vertical from the center of the pupil or even beyond this point. 



PLO conspicuously nearer to the lateral line than to the base of 

 pectoral fin. PVO in a straight series with the anterior PO. Fourth 

 PO elevated approximately to the level of the upper PVO. VLO 

 about midway between the lateral line and the base of ventral fin. 



Figure 18. — Diaphus chrysorhynchus Gilbert and Cramer 



5 VO. SAO in a very steeply inclined, straight line, the continua- 

 tion of which falls well behind the last VO. Interspace between 

 first (lower) and second SAO much smaller than that between the 

 second and the third (upper) SAO. 6 + 5 AO were counted in 11 

 cases, 6 + 6 AO in one case, each side being counted separately. 

 First anterior AO elevated to a level about midway between that of 

 the lower and that of the middle SAO. Last anterior AO also ele- 

 vated. Upper SAO and Pol close to the lateral line. First posterior 

 AO behind the base of anal fin. 4 Pre, equally spaced and curved, 

 widely separated from the posterior AO and with the upper organ 

 well below the end of the lateral line. 

 Known only from Hawaiian waters. 



DIAPHUS WATASEI Jordan and Starks, 1904 



Material investigated. Type specimen No. 51443, U.S.N.M. 



This species was identified by Gilbert, 1913 (p. 95) with D. coeru- 

 leiis Klunzinger 1871 and his example was followed by the present 

 author in the previously rendered key to the genus Diaphus (Parr, 



