228 EXrEDlTlUN OK THE " ALIJATUOSS," 1S9'J-1900. 



Diaphus signatus, sji. uov. 



Plate 3. 



Type 60 mm. long, from the surface at Hyclrographic Station 3798 (A, A. 

 27), near Nukuhiva Island, Marquesas Group. 



Most nearly related to Diaphus {Nijctojihus) splcndidm Drawer (Zoijl. Anz., 

 1904, 28, p. 399, fig. 7), differing in the smaller head and shorter snout, the 

 less elevated iuterorbital region which scarcely protrudes above the orbital 

 rim, and the more anterior insertion of the ventral fins. The preocular 

 luminous organ is apparently not divided into upper and lower portions, 

 ])ut has innnediately above it a distinct luminous dot surrounded by the 

 black pigment. In general proportions, fin rays, and number and distri- 

 bution of pliotophores, this species does not differ from D. splcndidiis. 



Lengtii of head 28 hundredths of total length without caudal; diameter 

 of eye 7; length of snout 4.3; length of maxillary 20; greatest depth of 

 body 18; least deptii of caudal peduncle 8; distance from snout to front 

 of dorsal, 45; to insertion of ventrals 41 ; to front of anal 64; to adipose 

 fin 80. 



D. 15; A. 15; P. 12 ; V. 9 ; lateral line 38; the 11th .scale over the 

 supra- ventral photophore, the 18th scale over the upper supra-anal, the 

 25lh over the postero-lateral. 



Form slender; snout short and bluntly rounded, its length little more 

 than half the diameter of orbit; maxillary long and slender, not widened 

 posteriorly, its middle well behind the pupil ; preopercular margin very 

 obliiiue ; gill-rakers slender, 6 + IP) in number on outer arch, the longest 

 three-fourths the diameter of the eye. 



Pectorals small, inserted low, but little above the U'vel of the veutrals, 

 which they fail to reach. Ventrals inserted well in ailvjince of the dorsal, 

 imiisually well developed, tlii'ir longer inner rays exteiuling to base of 

 third or fourlii anal ray. The vertical from the last dorsal ray falls 

 between the vent and tlie front of the anal. Last anal ray under the 

 middle of the adipose fin. 



Scales and much of the integument lost, but the general color was- 



