PROCEEDINGS OF THE NATIONAL MUSEUM. 411 



tlironuli lower rim of orbit and a little above the line from angle of 

 month to loot of ventrals; the hn narro\y, weak, its length L>| in head 

 Ventrals broad, stronger. Candal deeply forked. 



Color [in alcohol). — Body blackish brown (where the scales Inive dis- 

 a])peared). A spot at base of each venfral fin, and a i)air of si)ots on 

 interorbital space over the eye and the anterior rim of orbit, jet black. 

 Top of head and opercles, gill and month cavities, blackish. Scales 

 silvery, iridescent, reritoneum black. 



Twelve specimens, 3 to 3J inches long, from station 2S(» (snrface tow 

 net, lat. X. 21o 15' 49", long. W. 157° 44' 27"); and from liao ^lakanni. 



T,i2n\—^o. 47710, U.S.N.M. 



This species differs from Diajthusthefa and T>. em/rauli.s in the extreme 

 development of the preocnlar i>hotophore. 



MYCTOPHUM FIBULATUM, new species. 

 (Plate XXXVIII, fig. 3.) 



Head 3-,\-; depth 4i. D. 12; A. 19; P. IG; V. 8; pores of lateral 

 line about 27 or 28. 



Body compressed, its width about 2 in its depth. Least depth of 

 pednncle 25 in greatest depth of body. Dorsal and ventrals outlines 

 nearly similar, the depth of body a little greater at origin of first dor- 

 sal than at the nape. The pednncle somewhat expanded at base of 

 caudal fin. Head stout, comi^ressed. its dorsal outline parabolic, its 

 greatest width about 1?^ in its greatest depth, its width at anterior rim 

 of orbit 2^ in the greatest depth. Orbit large, circular, 2^ in head, its 

 upper rim nearly entering profile. Interorbital space nearly fiat, broad, 

 li in orbit. Snout steep, blunt, short, 2 in orbit, its tip a little above 

 the level of the lower edge of the pupil. Mouth somewhat oblique, 

 maxillary 1| in bead, reaching about one-fourth or one fifth of its own 

 length beyond the posterior rim of the orbit. Teeth very small, in 

 narrow bands on the jaws and palatines. Lower jaw with a very small 

 symphyseal knob, the sharp edges of the rami meeting in a slight ridge 

 in the median ventral line. Nostrils nearly midway between tij) of 

 snout and anterior rim of orbit, about on a level with the center of the 

 eye, the two openings very close together and nearly equal in size. 

 Orbital margin separated by a groove and a ridge from the preopercle. 

 Posterior preopercular margin somewhat rounded (injured), extending 

 obli(inely upward and forward. Opercle with a broad, rounded upper 

 angle and a small pointed triangular iirojection just above the base of 

 the i)ectoral fin, which it reaches. Bones of skull thin and fiexible. 

 About 18 gill rakers on anterior limb of first arch, slender, long, 2 iu 

 orbit. Scales large, thin, cycloid, deciduous (nearly all gone from the 

 single specimen except those of the lateral line and those with phos- 

 phorescent spots), interorbital space, snout, and lower jaws naked. 

 Cheeks and preopercle with very thin scales. 



