296 PISCES. 



a Trygon and finely serrated. The anterior part of the head is trun- 

 cated, and the pectorals instead of clasping it have each of their an- 

 terior extremities extended into a salient point, which gives the fish 

 the appearance of having horns. 



A gigantic species is occasionally captured in the Mediterra- 

 nean, the Raid cephaloptera, Schn. j Haie giorna, Lacep. V, xx, 

 3,(1) with a black back bordered with violet. 



FAMILY II. 



SUCTORIL CYCLOSTOMI, Burner., 



The Suctorii; as regards the skeleton^ are the most imper- 

 fect of fishes^ and even of all vertebrate animals. They have 

 neither pectorals nor ventrals ; their elongated body is termi- 

 nated before by a circular or semicircular fleshy lip, and the car- 

 tilaginous ring which supports it results from the soldering of 

 the palatines to the mandibularies. The bodies of all the ver- 

 tebrae are traversed by a single tendinous cord filled with a 

 mucilaginous substance without strangulations, which reduces 

 them to the condition of cartilaginous rings, scarcely distinct 

 from each other. The annular portion, a little more solid than 

 the rest, is not however cartilaginous throughout the whole of 

 its circle. They have no ordinary ribs; but the small bran- 

 chial ones, which are hardly perceptible in the Squali and 

 Rays, are here greatly developed and united with each other, 

 forming a kind of cage ; while there are no solid branchial 

 arches. The branchiae, instead of being pectinated as in 

 all other fishes, resemble purses, resulting from the junction 

 of one face of a branchia with the opposing one of its neigh- 

 bour. The labyrinth of the ear is enclosed by the cranium, and 

 the nostrils open externally by a single orifice, in front of 



(1) The Rale fabronienne, Lacep., II, v, 1,2, is most probably a mutilated indi- 

 vidual of the gioma, but the R. giorna, Lesueui-, Ac. Nat. Sc. Philad., appears to 

 differ from that of the Mediterranean, and may rather be the Mohulur, Duham., 

 second part. Sect. IX, pi. 17. As to the R. bank&itnne, Lacep., II, v, 3; Mana- 

 iia. Id., I, vii, 2; Diabolus marinus. Will., App. IX, 3; they unfortunately I'est on 

 no authentic foundation. Add the Cephaloptera viassena, Riss., p. ISiSregoodcc- 

 tenkee, Russ., I, 9. 



