282 DEEP-SEA FISHES OP THE ATLANTIC BASIN. 



Family AGONIDyE. 



Agonida:, Swainson, Nat. Hist. Fi.shes, 1839, ii, 181. — Gill, Arr. Fain. Fi.sbes, 1872, p. 6 (name only, to em- 

 brace Giinther, ii, pp. '211-L'lG). — Jordan and Gilbert, Hull, xvi, U. S. N. M., p. 722.— Uii.l Proc. U. S. 

 Nat. Mus., XI, 590, 1889. 



Body elongate, or more or less elevated, augular, covered with about eight longitiidi 

 nal series of large, bony, plates, which form a coat of mall; head externally entirely bony, 

 the plates often spinous; eyes large, i)laced high; suborbital stay euirassing the cheek; 

 mouth terminal or inferior; barbels often present; teeth small, in villiform l)ands on the 

 jaws, and often on the vomer and palatines also; gills 3i, no slit behind tlie hist; pseudo- 

 branchite very large, usually extending down the inner side of the opercle; gill rakers 

 small; gill membranes united, free or joined to the isthmus; ventral fins thoracic, dose to- 

 gether, imperfect, i, 2 or i, 3; spinous dorsal small, sometimes absent; anal short, similar 

 to soft dorsal, without spines; caudal narrow, few-rayed; ])ectorals entire, with bioad base, 

 the rays mostly simple; pyloric cicca few; air bladder none. (Jordan and Uilhert.) 



KEY TO THE DEEP-SEA GENERA OF AGONID^. 



I. Spinous dorsal present Agonin>e 



A. Gill membranes joiued to isthmus. 



1. Bony plates of body not spiny. 



a. Vomer toothless. No occipital pit [Agonus] 



2. Bony plates of body spinous. 



o. Vomer toothless PODOTIIECUS 



6. Vomi!r with teeth. 



Pectorals not notched. Bones of head thin and yielding Bathyagonus 



Pectorals divided by a deep notch into two portions Xenochirus 



II. Spinous dorsal obsolete. 



A. Gill membranes free from the isthmus AsPiDOriiORoiDiN.E 



1. Bony jdatcs of body keeled but spineless AspidophuROIDES 



PODOTHECUS, Gill. 



Podothecus, Gill, Proc. Nat. Sci. Phila., 1861, 259 (type, Podothecus perietethus, Gill=:^<7onMS acijienserinus, Tiles. ) 

 Body elongate, fusiform; head long, compressed, armed above; snout protruding much 

 beyond the small, inferior, U-shaped mouth; teeth very small, in villiform bands; none on 

 vomer or palatines; lower parts of head with barbels; gill membranes united to the isth- 

 mus, not forming a fold across it. Plates of body armed with spines; spinous dorsal 

 present. Ventral rays i, 2. {Jordan and Gilbert.) 



PODOTHECUS DECAGONUS, (Schneider), Jordan. (Figure 259.) 



Agonus decagonua, Schneider, Bloch's Syst. Ichth., 1801, 105. — GOnther, Cat. Fish. Brit. Mus., ii, 215; 



Chalh-nger Report, xxii, 1887, 63. — Collett, Norgcs Fiske, 1875, 40; Norsk. Nordh. Exped., 44, pi. il, 



figs. 11-12. — L1LL.IEB0RG, Sverig. och Norg. Fisk., 193. 

 Archagoniis decagonus, Gill, loc. cit. 



Aspidophiiriis spiiioxissimiis, KrOyer, Naturhist. Tidsskr., i, 1844, 250. — Gaimard, Voy. Skand., pi. v. 

 Agoiius 82>inosi8i<i»iiis, Gunther, Cat. Fish. Brit. Mus., 11, 214. 

 Leptagonus spinosUsimus, Gill, Proc. Acad. Nat. Sci. Phila., 1861, 167. 

 AnpidoplioruH malarmoides, Deslongchamps, Mem. Soc. Linn. Norm., ix, 1853, 167. 

 Braehiiopxis decagonus, Jordan and Gilbert, Bull, xvi, U. S. Nat. Mus., 727. 

 Podothecus ( Leplagoniis) decagonus, Jordan, Cat. Fish. N. Amcr., 1887, 114. 



Body elongate, compressed; head depressed; jaws equal; a pair of spines above the 

 snout, a second above the orbits, a. third on the nape, the latter the largest; barbels very 

 short and thick; scales with very prominent spines, 6 .series of scales between the ventral 

 fins and the vent; 4 between the vent and the anal fin; pectoral tins much longer than 

 head, one-fourth total with caudal. 



Kadial formula: D. vi, 7; A. 8; P. 14; L. lat. 41. 



Color, yellowish brown, marbled with darker. (Giinther,) 



