154 CLASS XIV. 



to the silvery covering of the choroid of the eye in fishes, and consists 

 of microscopic needle-shaped crystals. Comp. on these and some other 

 anatomical peculiarities of the Vaagmaer, Eeid in Annals of nat. Hist., 

 Sec. Series, iii. 1S49, pp. 456—477. 



Oymnetrus Bloch, Valenc. 



]sj"oTE. — CuviER {R. Ani. II. J). 219) joined the preceding genus 

 with Gymnetrus under this common name ; Valenciennes again 

 separated the genera. Gymnetrus differs from Trachyjyterus, an 

 allied genus, in the ventral fins being with one ray, which is very 

 long and increased towards the extremity by membrane. Body 

 without scales, with hard osseous points scattered ; lateral line un- 

 armed. Teeth none. Caudal fin none or small, confluent with 

 dorsal. 



Sp. Gijmneirus remipes Bl., Schn., Regalecus glesnc Ascan., Bloch Syst. 

 Ichth. Tab. 88, Encycl. meth. Poiss. PI. 86, fig. 258; North Sea, on the 

 Norwegian coast; becomes ten or twelve feet long.^ — Gymnetrus Banhsii 

 Valenc; comp. Hancock and Embleton, Account of a Ribbon Fish 

 {Gymnetrus) taken off the coast of NoHhumberland, Ann. of nat. Hist., Sec. 

 Series, iv. 1839, pp. i — 18, PI. i. 11.; this specimen was 12' 3" long. In 

 the Medit. Sea also one or two species of this genus occur, of 6 — 8 feet in 

 length, Gymnetrus Gladius Yaleno. {Gymnetrus lonr/iradiatus Jiisso), Cuv. 

 et Val. Poiss. X. PI. 298, and Gymnetrus telum Val. ibid. PI. 299. 



B. Mouth scarcely or not at all protractile, with aperture large, 

 oblique, the lower jaw ascending. 



Lophotes GiOENA. Body scaleless. Teeth small, scattered in 

 several rows in jaws ; small teeth in palate-bones and vomer. 

 Head with a vertical crest sustaining an elongate strong spine, the 

 first ray of dorsal fin. Dorsal fin extended through the whole 

 length of body, with numerous simple rays ; anal fin small, placed 

 towards the end of tail; caudal fin small, distinct. Yentral fins 

 very small, distant, adjacent to pectoral fins. 



Sp. Lophotes cepedianus Giorna, Mem. de I'Acad. de Turin, 1805 — 180S, 

 pp. 12 — 19, PL 2 (cited by Cuvier), Cuv. Ann. du Mus. xx. 1813, pp. 

 393 — 400, PI. 17; Cuv. et Val. Poiss. x. PI. 301 ; in the Medit. Sea; this 

 si)ecies becomes more than 4' long ; it has been observed only seldom. A 

 Japanese species, also very rare, is figured in the Fauna Japonica, Pisces, 

 Tab. 71, fig. 2. 



Cepola, L. Body covered with small scales. Teetli in jaws in 

 a single row, distant, subulate, thin, the middle in lower jaw 

 larger, in palate and vomer none. Dorsal and anal fins very long. 



