STOMIATIDAE 309 



Genus Odontostomias, gen. nov. 



Elongate; head short. Cleft of mouth straight; jaws rather strong. Teeth tapering to 

 sharp ends; first tooth in upper jaw rather small, fixed; second long, depressible, 

 followed by 2 or 3 outer small fixed teeth and i inner stronger depressible tooth ; lower 

 jaw with a pair of small depressible teeth at the symphysis, ., l^-t^^ , /,mx. 

 a strong fixed fang on either side, followed by an inner 

 depressible tooth and 3 or 4 outer fixed teeth; maxillary 

 teeth all small, more or less erect; two groups, each of i to 

 4 teeth, on the vomer; 2 to 5 teeth on each palatine; a single 

 pair of teeth on basibranchials or none. Teeth on gill-arches 

 in pairs. Postocular luminous organ well developed (d* .'') or 

 absent (? .''). Dorsal 20-23. Anal 23-26; origin nearly below 

 that of dorsal. Pectoral 7-9, without isolated ray. Pelvics 

 7-rayed, well behind middle of length. 



Two species. Genotype: Odontostomias mtcropogon, n.sp. e/?o. 



Examination of the skulls of the fishes of this genus shows Fig. 17. Upper view of skull 



that it belongs to the group containing Opostomias, Flagello- of Odontostomias mkropogon. 



stomias, Thvsanactis and Leptostomias, distinguished by the ("^-^ «/'o-epiotic;/r. frontal; 



, ' 111 r • 1 T l^t^- lateral ethmoid; meth. 



absence of post-temporals and the presence of panetals. In mesethmoid;/.. parietal ;/.m^. 



the form of the ethmoid region this genus seems to be nearest praemaxillary ; pto. pterotic; 

 to Opostomias, but diff'ers in having no isolated pectoral ray, ^of^- supra-occipital. 

 and in the fangs of the lower jaw not perforating the praemaxillaries when the mouth is 

 closed. The structure of the anterior part of the praemaxillaries bears some resemblance 

 to that found in Thysanactis, but the median process is much less developed and the 

 lateral projections are narrower. 



Odontostomias micropogon, n.sp. 



St. 269. 26. vii. 27. 15° 55' 00" S, 10° 35' 00" E. 4^^ m. net, horizontal, 600-700 (-0) m. : 2 

 specimens, 180-186 mm. 



St. 270. 27. vii. 27. 13° 58' 30" S, 11° 43' 30" E. Young-fish trawl, 200 (-0) m. : 8 specimens, 

 40-52 mm. 



St. 276. 5. viii. 27. 5° 54' 00" S, 11° 19' 00" E. I m. tow-net, oblique, no (-0) m. : 3 specimens, 

 38-45 mm. Young-fish trawl, i5o(-o)m. : 10 specimens, 39-290 mm. (The largest specimen is 

 selected as the holotype.) 



28. X. 25. 13° 25' N, 18° 22' W. 4i m. net, horizontal, 900 (-0) m. : i specimen, 90 mm. 



Depth of body 8| (young) to I2| in the length, length of head 7 to 8f . Diameter of 

 eye 45 to 6 in length of head, a little greater than postocular luminous organ. ^ Barbel 

 J to I length of head; stem black, terminating in a simple white portion, scarcely 



^ The postocular luminous organ is well developed in some examples, and is altogether wanting in others. 

 I have been able to determine the sex of two individuals, and find that the one with an organ is a male and 

 the one without a female. 



