354 PLAGIOSTOMATA. 



Genus II Cephaloptera, Dumeril. 



Dicerobatis, Blainville : Mobula, Rafin. : Pterocephala, Swainson. 



Pectoral fin not extended on to the sides of the head, which latter is truncated in 

 front, while on either side is a forwardly -pointing horn-like projection, which is 

 internally supported by fin rays. Mouth wide, nostrils not confluent. Teeth in jaivs 

 very small, flat or tubercidated, and in many rows. Tail whip-like, with a dorsal 

 fin situated above and between the ventrals, and with or destitute of a serrated spine. 



1. Cephaloptera giornse, Plate CLXXVII. 



Baia giornce, Lacep. v, p. 666, pi. xx, f. 3 ; Jenyns, Manual, p. 519. 



Cephaloptera giorna, Cuv. Regne Anim. ; Risso, Ich. Nice, p. 14, and Eur. 

 Merid. iii, p. 163, pi. v; Jenyns, Brit. Vert. p. 519; Yarrell, Brit. Fishes (ed. 2) 

 ii, p. 595, c. fig. (ed. 3) ii, p. 600 ; Mull, and Henle, p. 184 ; Val. in Webb and 

 Berthel. lies Canar. p. 97, pi. xxii ; Gray, Catal. Cart. Fish. p. 133; Thompson, 

 Proc. Z. Soc. 1835, p. 78, and Ann. and Mag. Nat. Hist, xx, p. 173, Nat. Hist, 

 Ireland, iv, p. 263; McCoy, Ann. and Mag. 1847, xix, p. 176, pi. xi ; White, Catal. 

 p. 141 ; Dumeril, Ich. i, p. 653, pi. vi ; Canestr. Faun, d'ltal. Pesc. p. 61 ; Moreau, 

 Poiss. de la France, i, p. 439. 



Baia cephaloptera, Bl. Schn. p. 365. 



Dicerobatis mobular, Blainv. Fauna Franc, p. 41. 



Pterocephala giorna, Swainson, Fishes, ii, p. 321. 



Cephaloptera fabroniana, Dumeril. 



Dicerobatis giornce, Giinther, Catal. vi ii , p. 496 ; Giglioli, Catal. Pesc. Ital. p. 55. 



Ox ray, Couch, Fish. Brit. Isles, i, p. 139, pi. xxxiii. 



Disk much expanded laterally, the width equal to at least twice the length, 

 and the outer angles pointed. The pectorals measured from their insertion 

 behind the head to their angles, equal half the width of the disk, sometimes less. 

 Tail equals nearly three times the length of the body, it is smooth in the first quarter 

 of its length, and with a spine which is serrated along its edges. Eyes small, 

 spiracles situated behind the eyes, than which they are larger. Mouth wide. 

 Teeth small, and in about 150 or 160 rows, the central ones being rounded. 

 Fins dorsal triangular, situated anterior to the spine ; ventrals of small size. 

 Skin smooth, with peculiar and minute scales porteriorly that are rough to the 

 touch. Colour bluish green superiorly, white beneath. 



Names. Ox-ray, from their horn-like heads : horned-ray. This fish was 

 first described by Professor Giorna in the " Memoires de l'Academie des Sciences 

 de Turin," 1805-8, p. 4. 



Habits. Said to roam about in pairs, and dies almost immediately on being 

 removed from the water. As only one example of this fish has been observed 

 wandering to our shores, its habits, as may be expected, have not been recorded. 



Breeding. Have been observed to occasionally go in pairs, the male being 

 usually the smaller of the two, and Risso alludes to one case in which, after the 

 female had been captured, the male lingered for three days around the boat, at the 

 end of which time it was observed floating dead on the surface. 



Habitat. Mediterranean. One was captured on the southern coast of Ireland 

 about 1830, and is now in the Royal Dublin Society's Museum, it is 45 inches 

 broad. 



The specimen figured is 57 inches broad, from Algiers, and in the National 

 collection. The caudal fin being partly removed, is restored in accordance with 

 the length observed by Dumeril. This fish attains to an enormous size. 



