NO. 1114. PBOCEEDINGS OF THE NATIONAL MUSEUM. 431 



witb brownish dots. Lips, under side of head, branchiostegal mem- 

 branes, gill cavities, back part of mouth, distal part of first dorsal, base 

 of i)ectoral, and most or whole of ventral fins brownish black. Ventral 

 ])art of body from the isthnuis to or beyond origin of anal bluish black; 

 a faint dark elongate spot under the i)osterior part of orbit. ]*erito- 

 neum bright silvery, dotted with black. 



Young more slender, less deep, eye larger. 



Seven specimens, 4^ to 8 inches long, from stations 34:70 and 3472; 

 343 and 295 fathoms, respectively. 



Type.—^o. 47704, U.S.N.M. 



OPTONURUS ATHERODON, new species. 



(Plate XLVI, fig, 1.) 



Head 5; depth 5|; B. 7. First dorsal 1, 10 to I, 11; anal about 130; 

 pectorals 20 to 23; ventrals 10. 



Series of large, cavernous pits and depressions on top of head; supra- 

 scapular region and preorbital covered with thin translucent integu- 

 ment. Head very cavernous, compressed. Snout broad, short, li in 

 orbit, its preoral portion 3 in orbit. Interorbital space fiat, IJ to 1^ 

 in orbit. A median ridge extending from behind tip of snout over the 

 interorbital space to about opposite the middle of the orbits, where it 

 joins a transverse ridge. The interorbital space between this ridge 

 and edges of the orbits covered by a thin, translucent membrane be- 

 neath which are large cavities. A pair of small, curved ridges (with 

 their convex sides directed medianward) on the occiput, (^uite promi- 

 nent bony rims around the nostrils. Mouth terminal, lateral, oblique, 

 jaws about equal, the lower, little included, maxillary reaching middle 

 of orbit, nearly half as long as head, its posterior end much narrowed 

 and directed ventrally. Premaxillary nearly as long as maxillary, 

 heterodont, with an outer series of widely set canines with distinctly 

 arrow-shaped tips, and an inner villiform band. Mandibular teeth 

 small, closely set in a very narrow baud, the inner series slightly 

 enlarged. Orbit very large, ?>^ in head, its upper edge nearly entering 

 the profile. Preorbital narrow, 2^ in orbit. Posterior edge of preopercle 

 nearly vertical, slightly incurved. Barbel a little more than one-half 

 length of orbit. Gill membranes rather broadly united in a free fold 

 across the isthmus. The length of the anterior gill slit 1.^ to \\ times 

 the interorbital Avidth. Body compressed, its greatest width one-half 

 its height. Scales very deciduous, of moderate size, tliickly covered 

 with short blackish spinelets not arranged in series. Head apparently 

 entirely scaled; 10 to 12 series between origin of dorsal and lateral 

 line. Second dorsal spine smooth. If in head. Base of first dorsal 

 equal to interorbital space. Origin of first dorsal over axil of pectorals. 

 Second dorsal low; distance of its origin from end of first dorsal nearly 

 three times the base of the latter. Origin of anal under or slightly in 



