9. oPHiDiuM. 377 



of moderate Bize. Dorsal, caudal, and anal fins continuous, low ; 

 ventral fins replaced by a pair of bifid filaments (barbels), inserted 

 below the glossohyal. Teeth in the jaws, forming bands, generally 

 small ; those on the vomer and the palatine bones small. Lower 

 jaw received within the upper. Vent situated at some distance 

 behind the pectoral. Seven bran chiostegals; gill-openings very wide ; 

 gills four, a slit behind the fourth ; pseudobranchiae and air-bladder 

 present. No pyloric appendages. 

 Mediterranean. Atlantic. 



1. OpMdium barbatum. 



Ophidium, Plin. iii. cap. 9 & 11 ; Rondel, xiv. c. 2. p. 397 ; Gesner, 



pp. 91, 104 ; Aldrov. iii. c. 26. p. 353. 

 Grillus, Bellon. De Aquat. pp. 132, 133 ; Gesner^ p. 92. 

 Ophidion, no. 1, Artedi, Syn. p. 42. 

 Ophidium barbatum, pt., L. Syst. Nat. i. p. 431 ; Brouss. Phil. Trans. 



1781, p. 430. tab. 23 ; Brunn. Ichth. Mass. p. 15 ; Bl. taf. 159. fig. 1 ; 



Bl. Schn. p. 484 ; Lacep. ii. p. 279 ; Delaroche, Ami. Mus. xiv. p. 275 ; 



Turton, Brit. Faun. p. 88 ; Cuv. Bigne Anini. ; Bisso, Ichth. Nice, 



p. 96, and Eur.Mmd. iii. p. 211; Jen. Man. p. 481; Yarr. Brit. Fish. 



2nd edit. ii. p. 415, and 3rd edit. i. p. 76. 

 Enchelyopus, no. 4, Klein, Pise. Miss. iv. p. 52. 

 Ophidium barbatum, 31)111. Abhandl. Bert. Acad. 1843, p. 150. taf. 4. 



fig. 1 (au'-bladder). 



* D. ca 140. A. ca 120. 



The outer pair of the barbels is considerably longer than the inner, 

 and shorter than the head. The depth of the head is contained once 

 and two-thirds in its length. The lower branch of the outer branchial 

 arch with five or six gill-rakers, nearly half as long as the diameter 

 of the eye. The end of the ethmoid is curved, hook-like. Head 

 entiidy naked. Vertical fins edged with black. 



There are two small bones joined to the first vertebra, directed 

 downwards ; they are connected by a thin transverse filament with a 

 large crescentic bone, fitting into the anterior end oi the air-bladder, 

 and situated between a pair of thick processes of the fourth vertebra. 

 Muscles attached to the anterior bones and to the crescentic bone 

 draw them forwards. {Mull.) 



Mediterranean. 



2. Ophidium broussonetii. 



Ophidium bai-batum, pt., Brouss. Phil. Trans. 1781, p. 436. 



broussonetii, Midi. Abhandl. Berl. Acad. 1843, p. 150. taf. 4. tig. 3 



(air-bladder). 



D. ca 140. A. ca. 120. 



Very similar to 0. barbatum, but with only four gill-rakers on the 

 lower branch of the outer branchial arch, and with a different struc- 

 ture of the air-bladder. No hook-like prominence at the ethmoid. 



Air-bladder ovate, without a contracted part. There is no sepa- 

 rate bone fitting into the anterior portion of the air-bladder. The 



