462 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.50. 



Dorsal rays 14 or 15; anal rays 19 to 21; scales in lateral series 38 to 

 40; distance from snout to dorsal insertion slightly more than half 

 length to base of caudal; minute teeth in both jaws; dorsal surface 

 of body dark, sharply separated from silvery flanks and ventral 

 surfaces. 



5. STOMIAS ATRIVENTER Gannan. 



Two specimens, one 155, the other 85 mm. in total length from 

 Albatross station 2791, in 677 fathoms, 38° 08' S., and 75° 53' W. 

 off Lota, Chile. Both of these are badly preserved, especially the 

 larger. The following features may be made out with reasonable 

 certainty : 



Total length 155 nun. 85 mm. 



Depth in length 12 times. 14 times. 



Head in length 9 times. 9 times. 



Dorsal rays 16? 16 



Anal rays 20 19 



Ventral rays 5 5 



Luminous organs between pectoral and ventral 46 45 



Between ventrals and anal 13? 12 



Between first anal ray and caudal 16? 16 



Along branchiostegal membrane 18 18 



Along gular region 15? 11 



6. IDIACANTHUS RETRODORSALIS, new species. 



Plate 4, fig. 2. 



A single specimen, Cat. No. 76857, U.S.N.M., from Albatross 

 station 2791, off Lota, Chile, in 677 fathoms. It has lost a part of 

 the tail, and its total length can not be stated, but it is 125 mm. 

 from the snout to the anus. There are left 20 vertebrae beyond 

 the anus. Giinther gives 30 in Idiacantlius ferox. 



Head 4J in distance from snout to ventral fins, 7 in distance to 

 anus; depth 23 in latter and half that of the head; snout 4 in head and 

 2^ in postorbital part of same; eye If in snout, 4 in postorbital 

 part of head; barbel one and one-half times length of head; dorsal 

 rays more than 44; anal rays more than 27, there beiiig 22 rays of 

 dorsal in front of anal insertion; ventral r&js 6; no pectoral; teeth 

 in upper jaw shghtly shorter than those in lower, arranged in four 

 groups, each increasing in size posteriorly; numbers in groups as 

 follows: 3, 4, 3, 4, last teeth of second and third group longest, those 

 in upper jaw totalhng 14; teeth in lower jaw in six groups, each 

 increasing in length posteriori}^ save in the last, which is composed of 

 several small subequal teeth; these groups have the following num- 

 bers of teeth: 6, 5, 3, and 4, totalling 18 in aU; tongue apparently 

 toothless (crushed condition of lower jaw may have resulted in loss 

 of tongue teeth, but this is not probable); a pair of teeth on either 

 side of vomerine region just behind ends of premaxiUaries ; two on 

 each lateral roof of mouth directly under each eye. 



