^T8"9l''] proceedings of the national museum. 349 



inwards. Tip of inaudible enlarged to form a knob which fits into a 

 toothless depression just behind head of vomer, the vomer extending 

 well beyond the tip of lower jaw. Teeth on head of vomer and hnob 

 of mandible similar, slightly larger than those on sides of jaw. Ante- 

 rior part of shaft of vomer (immediately behind depression for tip of 

 mandible) with a median series of strong conical teeth, the largest in 

 the mouth. These are usually accompanied by smaller lateral series, 

 and followed by a narrow band of very small conical teeth which reach 

 backwards to middle of mouth. 



Length of head equal to that of trunk, and one-third that of tail. 

 Posterior line of occiput midway between front of dorsal and middle of 

 eye. 



Gill openings broadly lunate, the upper margin continued as a mem- 

 branous fold across base of pectorals. The vertical length of the slit 

 is one-third of the snout, and the two are separated by an interspace 

 two thirds the length of the slit. 



Pectorals narrow, one-half snout. 



Color very dark brown, the tins black, the pores of the lateral line 

 white. 



A single specimen, ISf inches long, from Station 2792, in 401 fathoms. 



OPHISOMA SWAINSON. 



KEY TO THE SPECIES OF OPHISOMA. 



a. Vent submedian, the body and tail abont equal in length. Upper jaw but little 



projecting, lips thin balearicum 



aa. Vent anterior in position, the tail much longer than the body. 



i. Snout short and broadly rounded, but little projecting beyond tip of mandible. 



Tail nearly twice length of body macrurum, sp. nov. 



bb. Snout long and acute, projecting well beyond tip of mandible, 

 c. Tail less than twice length of body. 



d. Eye large, equaling snout, 5 in head MYSTAX 



dd. Eye small, one-half snout, 8 in head prorigerum, sp. nov. 



cc. Tail much more than twice length of body nitfns 



Ophisoma balearicum ? Delaroche. 



Four immature specimens from the Bay of Panama, taken at a depth 

 of 33 fathoms (Station 2797), are provisionally referred to this species. 

 They agree perfectly with the descriptions of 0. compressum Poey and 

 0. mellissii Giinther, and show in addition a brownish-black blotch 

 below the eye not noted in descriptions of other species. From the 

 current ilescriptious of 0. halearicwn they differ in the larger mouth, 

 the maxillary reaching to below the middle of the eye. It is probable, 

 however, that adults of all the species of Ophisoma agree in this re- 

 spect. Direct comparison of specimens from the Mediterranean with 

 those from the West Indies and from the tropical Pacific may show 

 them to be specifically distinct, but it seems more advisable for the 

 present to consider balearicum a widely distributed form agreeing in 



