92 MEMOIRS OF THE CARNEGIE MUSEUM 



19. Diaphus anteorbitalis sp. nov. (Plate XII, fig. 1.) 



Type 93 mm. long to base of caudal, from Station 4968, off Shiwo Misako 

 (33° 24' 50" N., 135° 38' 40" E.), depth 253 fathoms. 



Very closely allied to D. adenomus Gilbert from the Hawaiian Islands, 

 differing only in the greater development of the circumocular luminous bodies, 

 in the slightly higher position of the suprapectoral photophore, and in the 

 larger eye. 



Measurements in hundredths of total length to base of caudal: Length of 

 head 28.5; diameter of eye 7.5; interorbital width above middle of eye 9; length 

 of snout 5; of maxillary 22; greatest depth of body 22; least depth of caudal 

 peduncle 11; distance from tip of snout to front of dorsal 43; to base of outer 

 ventral ray 43; to base of last dorsal ray 60; to front of anal 64; to last anal 

 ray 81; to adipose fin 80; length of base of anal fin 18; of dorsal fin 19. 



Dorsal rays 15 (3 rudiments; last ray cleft to base); anal rays 15 (2 rudi- 

 ments); pectoral rays 12; ventral rays 9, the outer ray short, rudimentary. 

 Scales of lateral line 36, the third supra-anal photophore on the 18th scale, the 

 posterolateral on the 25th. Gill-rakers 5 + 11. 



Diameter of eye about one-fourth length of head (about one-fifth head in 

 D. adenomus). Origin of dorsal and base of outer ventral ray in the same 

 vertical; last dorsal ray over the vent; last anal ray under the adipose fin. 

 Pectoral reaching a point halfway between fourth thoracic photophore and base 

 of ventral. Longest ventral ray reaching to or nearly to the vent. 



A well-developed supra-orbital luminous body, as in D. adenomus, found 

 only in these two species. It is in the form of a narrow streak along the 

 upper border of the orbit, not extending behind the pupil; a small superior 

 pre-orbital, in its usual position above the nostril; a third luminous body occu- 

 pies the position of both suborbital and inferior pre-orbital, extending on the 

 inferior border of the eye to or beyond the middle of the orbit, becoming 

 abruptly narrowed beneath front of eye and sending a narrow upward extension 

 nearly to the level of the superior pre-orbital. In D. adenomus, both the supe- 

 rior pre-orbital and the extension between eye and nostril are lacking. Supra- 

 pectoral photophore above the angle of the opercular flap, slightly nearer base 

 of pectoral than lateral line, accompanied below by a small glandular body. 

 Fourth thoracic and third ventral low, but little above the level of the ventral 

 base. Supraventral midway between the lateral line and the ventral base, or a 

 trifle nearer the lateral line. Supra-anals in a nearly straight line, the middle 

 spot slightly behind the line which joins the other two and passes just caudad 



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