CHONDHOPTERYGII BRANCHIIS FIXTS. 291 



disk, from its union with the extremely broad and fleshy pec.torals 

 which are joined to each other before or to the snout, and which ex- 

 tend behind the two sides of the abdomen as far as the base of the 

 ventrals. The scapulae of these pectorals are articulated with the 

 spine behind the branchiae. The eyes and spiracles are seated on 

 the dorsal surface, the mouth, nostrils, and orifices of the branchiae 

 on the opposite one. The dorsal fins are almost always on the tail. 

 The ova are brown, coriaceous, and square, the angles extended 

 into points. We subdivide the genus as follows: 



Rhinobatus, Schn.(l) 



The Rhinobati connect the Rays with the Squali by their thick 

 fleshy tail, furnished with two very distinct dorsals and a caudal; 

 the rhomboid formed by their snout and their pectorals is acute in 

 front and narrower in proportion than in ordinary Rays. Indepen- 

 dently of this they have all the characters of the latter genus; their 

 teeth are crowded and planted in a quincunx order like small flat 

 paving-stones. 



Some of them still have the first dorsal on the ventrals. (2) 

 In others it is much further "back. 



Such are the Mediterranean species, jS. rhinohatus^ L. ; Will., 

 D, 5, f. 1; and that of Brazil, R. clectricus, Schn., Marcgr. 152, 

 which has been said to participate in the properties of the 

 Torpedo; this however has not been proved. 



There is another species, Rh. gramtlaius, the skin of which 

 is granulated. (3) The 



Rhina, Schn. 



Only diflers from Rhinobatus in a short, broad, and rounded 

 snout. (4) 



(1) Viv60a.Tcg, which Gaza translates by Squaiiiw-raia, is the Greek name of 

 these fishes, which were considered by the ancients as produced from the union of 

 the Ray with the Squatina. 



(2) Rhin. Isevis, Schn. 77, Russel, 10, and-ff/i. Djiddensis, Forsk., 18, which pro- 

 bably form but one species. It is to it must be referred the fig-, of the Rhinobate, 

 Lacep., V, vi, 3, and that of Duhamel, part II, Sect. IX, pi. xv. 



(3) N.B. The jR. thouin, Lacep., I, 1, 3, is a variety of the common Rhinobatus. 

 The Raid halavi, Forsk., also appears to be the same. Add the Suttivara, Russ., 

 XI. 



(4) Rhina ancylostomus. 111., Schn., 72, to which the editor improperly adds 

 the Raie chinoise, Lacep., I, ii, 2, which, as well as can be determined from a 

 Chinese figure, rather approaches the Torpedo. 



