NO. 15 TWO NEW EELS AND A NEW FLATFISH REID 3 



Parr ^ has given a useful discussion of the congrids related to Ari- 

 oso ma, in which he synonymizes a large number of genera and shows 

 that Jordan and Hubbs' revision of the Japanese genera' (the only 

 recent revisional attempt of any great scope) cannot be accepted with- 

 out modification. No one seems to have utilized the labial bones in 

 defining genera, save in the case of Urocongcr (Bleeker, Schmidt), 

 although these structures seem to be important. 



The writer has studied a number of species of congrids from both 

 the Atlantic and the Indo-Pacific and finds that most of them fall into 

 apparently well-defined genera, based on the formation of the labial 

 bones, the presence or absence of a free upturned upper lip, and the 

 form of the vomerine patch of teeth. Of Ariosoma and related groups, 

 the following have been studied : A. selcnops Reid, A. balaerica (de la 

 Roche),* A. gilherti (Ogilby), and several Japanese forms, which may 

 (according to Jordan and Hubbs) be referable to distinct genera. Of 

 Proniyllantor, two species, P. alcocki Gilbert and Cramer and P. per- 

 turhator (Parr), have been examined. The type specimens of the type 

 species of all the genera referred below to the synonymy of Cofigrina 

 (save Pseudoxcnomystax dtibins Breder) have been studied, as well 

 as examples of Bathyuroconger braueri (Weber and de Beaufort) and 

 of Uroconger lepturus (Richardson). The writer cannot see that 

 Uranoconger Fowler and Microcephalocongriis Fowler differ from 

 the species of Congriiia in anything but relatively unimportant specific 

 dififerences. 



The key given is entirely provisional, since many more species and 

 genera will have to be examined to determine their exact relationships, 

 but it is felt that the groupings adopted are more natural than any 

 hitherto proposed. 



KEY TO GENERA OF CONGRIDAE DISCUSSED IN THIS PAPER 



la. Upper lip turned upward into a flange ; bones of the facial canal not send- 

 ing pointed processes into the upturned lip-flange. 



Ariosoma Swainson (and related genera), 

 lb. Upper lip without flange; bones of facial canal sending pointed processes 

 to edge of lip. 

 2a. Teeth of vomer not extending far back on the shaft in a single series ; 

 inner bony casing of facial canal sending 2 or 3 short processes down- 

 ward to edge of the moderately extensible upper lip. 



^ Bull. Bingham Oceanogr. Coll., vol. 3. art. s. pp. 19-31, 1932. 



^ Mem. Carnegie Mus., vol. 10, no. 2, pp. 191-197, 1925. 



"American specimens; Norman (Ann. Mag. Nat. Hist., ser. 9, vol. 15, p. 314, 

 1925) gives data to show that the American Ariosoma opisthophthalma (Ran- 

 zani) differs from A. balaerica. 



