170 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



POLYACANTHONOTUS, Bleeker. 



Polyacanthonotus, Bleeker, 1875. — Gujjther, Challenger Report, xxn, 1887, 243 (as subgenus). 

 Zanotacanthus, Gill, Johnsons' Cyclopaedia, 1876, in, 883. 

 Paradoxichthys, Giglioli, Nature, xxv, 535, 1882. 

 Teratichthys, Giglioli, loc. cit. 



Notacanthids, with very slender, elongate body, and inferior mouth, and the snout pro- 

 longed into a proboscis-like tip, resembling that of Mastacembelus; its length at least one- 

 third that of the head. Dorsal fin represented by numerous slender, curved, flexible, dis- 

 joined spines, the first of which is placed some distance behind the vertical from the origin 

 of the pectoral. Anal composed of a smaller number of longer, slender, flexible spines, 

 passing at a point some distance behind the last of the dorsal spines into a low, short, anal 

 fin. Pectorals moderate, slender, placed above the median line of the body, and close to the 

 lateral line. Ventrals slender, entirely separate, not reaching to the vent. Scales incon- 

 spicuous or probably absent. Lateral line conspicuous, descending from the angle of the 

 operculum in a strong, broad curve to below the middle region of the body at a point not 

 far from the vent. Teeth very fine, in rows upon each jaw : stronger teeth upon the palate, 

 arranged in the form of a horseshoe. The ventral with one spine. 



Type, Notacanthutj Eissoanus, Ue Filippi and Verauy. 



POLYACANTHOXOTUS RISSOAXUS, (De Filiiti and Verany), Gunther. (Figures 188; 194 A, B.) 



NotacaulhiiK lacerta, Risso, Unpublished Manuscript. 



Noiacanthwt Bissoanus, Br. Filipiu and Veraxy, Mem. Accad. Sci. Torino, xvin, 1859, 187-99; Nota sopra 

 alcnni Pesci del Mediterraneo, 1857,3. — Gunther, Cat. Fish. Brit. Mus., in, 545. — Camestrini, Pesci 

 d'ltalia, 118.— Giglioli, Elenco, 34; Nature, xxv, 535.— Moreau, Hist. Nat. Poiss. France, 162.— Vail- 

 lant, Exp. Sei. Travailleur et Talisman, 335, pi. xxvn, tig. 1. 



Kotacanthus ( Polyacanthonotus) rissoanus, Gunther, Challenger Report, xxn, 250 (description and figure re- 

 late to another species). 



Paradox ichlhyx Garibaldianm, Giglioli, Nature, xxv, 535. 



A Notacanthoid fish, slender and elongate in form, its greatest height, above the anus 

 and near the middle of the body, one-fifteenth of the length of the body; its height at the 

 shoulders about one-twentieth. The length of the head is about one-eighth of that of the 



Kotacantliite laverta, Riseo. 



FACSIMILE OF RISSO'S DRAWING, MADE BY PROFESSOR GIGLIOLI. 



body. Snout very elongate, oue-third of the length of the head; as long as the height of 

 the body at the shoulders, and three times the diameter of the eye. In form resembling 

 that (if Mastacembelus. "The condition of the type," remarks Vaillant, "does not allow us 

 to estimate the size of the mouth, but its commissure does not reach tbe anterior edge of the 

 orbit. Its form is analogous to that in other species of the genus, that is to say, its inferior 

 teeth are exceedingly fine and closely set, in the jaws, while there are stronger teeth upon 

 the palate, where they are arranged in the form of a horseshoe." 



Eye moderate in size, its diameter one-eighth the length of the head; interorbital space 

 very narrow, not one-half the diameter of the eye. Branchial opening large. Operculum 

 truncated posteriorly. 



Vent in front of the middle of the body. 



No traces of scales. The lateral line, however, is conspicuous, and it descends from the 

 upper angle of tbe operculum to the middle of the body, or a little below it, in the vicinity 

 of the region of the vent. The first dorsal spine is placed two thirds times its own length 

 back of the vertical from the axil of the pectoral, and its length is less than the diameter of 

 the eye. The highest dorsal spines, those in the posterior third of the fin, are twice as long 

 as the diameter of the eye. The spines are all slightly curved backward, and there is a soft, 



