Jordan and Evennann. — Fishes of North America. 2511 



operculum. A single, short, feeble spine on the shoulder, but none upon 

 the operculum or preoperculum, though certain projections seem to show 

 above the eye, doubtless due to the shrinkage of the integument upon the 

 underlying projections of the bone. Mouth very wide, the extremity of 

 the maxillary much dilated; posterior nostrils A^ery wide and separated 

 from the eye by a small, spinous projection of bone; teeth in narrow 

 bands, that on the vomer V-shaped, with the 2 arms straight. A few 

 large scales in a row starting from the upper angle of the gill opening 

 and terminating over the axle of the pectoral. Gill rakers on outer arch 

 rather numerous, long and slender. Pseudobranchiai represented by 2 

 minute globules. Deep sea; 2 species known. ("Named in honor of 

 Prof. Karl Mobius, director of the Royal Zoological Museum in Berlin, 

 who has added ranch to our knowledge of marine life by his noble work, 

 Die Fauna der Kielerbucht, and by numerous other writings.") 



2883. M(EBIA PROMELAS (Gilbert). 



Head 2 in trunk ; depth 3. Body 'i\ to 3^ in tail. Tail produced into a 

 filament, the caudal basis extremely narrow, supporting 5 long slender 

 rays which are firmly bound together. Mouth terminal, large, the maxil- 

 lary much dilated at tip, reaching well behind the eye. If in head; lower 

 jaw included, the tip slightly produced. Teeth in villiform bands on 

 mandible, premaxillary, vomer, and palatines, the band on mandible very 

 narrow, that on vomer with the diverging arms much incurved, the ante- 

 rior angle rounded. Tongue toothless, some of the basibranchials form- 

 ing a sharply elevated dentigerous crest. Gill laminae extremely narrow, 

 the gill rakers of outer arch very long and slender, 1 (with 4 rudiments) 

 above angle, 15 below. Infraorbital chain with 6 mucous sinuses, the 

 mandible with 5, preopercle with .^>, and a number on top of head; these 

 are all bridged over with very delicate membrane which is easily rup- 

 tured. A row of low, strong spinous points directed posteriorly on the 

 ridge running backward from the eye; no other spines on head, though 

 a number of short spinous points are made evident when the skin is re- 

 moved; opercular spin*^ rather weak. A distinct membranaceous flap runs 

 along the projecting edge of shoulder girdle, connecting pectorals with 

 upper end of gill flap; pectorals slender, equaling postorbital part of 

 head; ventrals each of a liifld filament, th(^ two branches joined at the 

 base for a very short distance, variable in length, reaching to or nearly to 

 tips of pectorals, usually contained about 1^ times in head; dorsal begin- 

 ning a trifle behind base of pectorals, its distance from occiput equaling 

 distance of latter from front of eye. Scales very small, apparently cov- 

 ering a part of top of head; 3 series of large pores on sides; 1 from 

 upper end of gill slit backward parallel with dorsal outline; a second 

 along middle of sides; the third beginning halfway between base of pec- 

 torals and ventral outline, extending backward on belly and along base 

 of anal tin, these lines all somewhat indistinct, and it can not be deter- 

 mined how far they extend backward. Color light brown; head (except 

 occiput), mouth, gill cavity, and abdomen jet-black; fins dusky. This 

 species closely resembles Moebia gracilis (Giinther), from New Guinea, dif- 



