9. oPHiDiuM. 377 



of moderate size. Dorsal, caudal, and anal iins continuous, low ; 

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

 below the glossoliyal. 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 branchiostegals; gill-openings very wide ; 

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

 present. No pyloric appendages. 

 Mediterranean. Atlantic. 



1. Ophidium barbatum. 



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



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

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

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

 Ophidium barbatuiu, pt., L. Si/st. Nat. i. p. 431; Brouss. Phil. Trans. 



1781, p. 436. tab. 23 ; Briinn. Ichth. Mass. p. 15 ; Bl. taf. 159. fig. 1 ; 



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



Turton, Brit. Faun. p. 88 ; Cuv. Regne Anim. ; Misso, Ichth. Nice, 



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



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

 Enclielyopus, no. 4, Klein, Pise. Mi.'is. iv. p. 52. 

 Opbidimn barbatum, 3Iiill. Ahhandl. Berl. 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 vnth. five or six giU-rakers, nearly half as long as the diameter 

 of the eye. The end of the ethmoid is cur\-ed, hook-like. Head 

 entirely 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 creseentic bone, fitting into the anterior end of the air-bladder, 

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

 Muscles attached to the anterior bones and to the creseentic bone 

 draw them forwards. {MiiU.) 



Mediterranean. 



2. Ophidium broussonetii. 



Ophidium barbatum, pt., Bronss. Phil. Trans. 1781, p. 436. 



broussonetii, 3Iull. Abhandl. Berl. Acad. 1843, p. 150. taf. 4. fig. 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-Uke prominence at the ethmoid. 



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

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



