DISCUSSION OF SPECIES AND THEIR DISTRIIJUTKJN. 381 



Ventrals composed of several rays, slightly in advance of the pectorals, which arc narrow. 

 Bones flexible; mucous cavities of the head of moderate capacity. Pseudobranchiae nunc. 

 (Giinther.) 



ONOS, Risso. 



Onus, Risso, Hist. Nat, Eur. Mr-rid., 1826, in, 214 (type, G. mu8tellali.).—GihL, Proc. Acad. Nat. Sci. Pliila., 

 1863, 240. — Jordan & Gilbert, I'.ull., xvi, 1'. S. Nat. Mus., 796. — Collett, Vid. Sel.sk. Forhandl., 

 Cliristiania, 1891, No. 11. 



Motella, Cuvier, Regno Animal, ed. 2, n, isi>;l, 334. — GCntiier, Cat . Fish. Brit. Mus., iv, 364. 



Molvella and Motella, Kaup, Wiegm. Archiv., 1859, 90. 



Gadoids with body rather elongate, covered with minute scales; head not compressed; 

 upper jaw longer; snout with 2 barbels and chin with 1 ; teeth on jaws and vomer in 

 bands; palatines toothless; dorsal fins 2, the anterior composed of small fringe like rays 

 concealed in a groove, preceded by a single long ray; second dorsal and anal long and 

 similar; caudal rounded or lanceolate; tail isocercal; ventral fins with from 5 to 7 rays; 

 chin with a barbel. 



KEY TO THE SPECIES OF ONOS. 

 [From Collett.] 



I. First raj "f first dorsal short (equal to or slightly longer than snout). 



A. Pectoral rays about 11 [O. pacificus] 



1. Pectoral rays about 17. 



a. Longitudinal diameter of eyes equal to or less than width id' interorbital space. 



' Height of body 7.1 in total length, v. 6 O. MEDITEKRANEUS 



* * Height of body l>; in total length, v. 7 <). GUTTATUS 



5. Longit udinal diameter of ej es greater than width of interorbital space. 



* Head large, its length about 4+ in total [O. MACROPTHALMUS | 



' "Head small, its length about 5 £ in total O. BISCAYENSIS 



2. Pectoral rays 22 or more. 



a. Longitudinal diameter of eve equal to or less than interorbital space, 



First ray of first dorsal equal to diameter of eye O. VULGARIS 



First ray of iirst dorsal greater than diameter of eye O. REINHAKDTH 



b. Longitudinal diameter of eye great, larger than interorbital space O. carpekterii 



II. First lay of lirst dorsal long (equal to head), color uniform salmon or brick red O. ENSIS. 



ONOS ENSIS, (Reinhardt), Gill. (Figure 327.) 



Mottllaensis, Reinhardt, Koii.Ved.Sel.sk. Math. Natura, Copenhagen, vi, 1837; ex. vn, 1838; 116, 128.— Col- 

 lett, Forh. Vid. Selsk. Cliristiania, 187S, No. 17; Norske Nordhavs Exji., 1890, Fish, 134. — LtJTKEN, Vid. 

 Medd. Xatnrli. Foren. Copenhagen, 1881, 236. 



Onos ensis, Gill, Proc. Acad. Nat. Sci., Phila. 1863, 241. — JORDAN and Gilbert, Bull, xvi, U. S. Nat. Mus- 

 797.— GONTHER, Challenger Report, xxti, 98.— Collett, Forh. Vid. Selsk, 1891, No. 11. 



Onos rufiis, Gill, Proc. U. S. Nat. Mus., \ t. L883, 259.— Jordan, Cat. Fish. N. A., 128. 



Head small, its length .">'-(> in total. Bye small, its diameter one-half the length of 

 the snout. Vent nearly median. First dorsal rays prolonged, its long as head. Teeth in 

 villiform bands, small and uniform. 



Radial formula: D. 59; A. 44-46; P. 22-27; V. 8. 



This form is known from Greenland, whence the museum at Copenhagen obtained 2 

 specimens, taken in 1836 from the stomach of a seal (Cystophora) at Otuenak (lat. 70° N"). 

 Another was found in 1882 by the IT. S. Fish Commission steamer Fish Hawk in hit. 40°, off 



the coast of New Jersey, in l.lllli fathoms. 



The body is unusually high, the greatest height at anus contained 4.] times in length ex- 

 clusive of caudal. The head enters 5J times in the length to end of caudal peduncle and 

 (i times in total length; its width at cheeks equals two-thirds of the head's length. 



The eyes are rather large, nearly as long as snout and the interorbital area, ami are 

 entirely in the anterior half of head, the posterior margin of the orbit nearly equidistant 

 betweeu the tip of the suoul ami the posterior margin of the operculum. The mouth is 



