22. MYLIOBATIDiE. 49 



of the tail, covered I)y an armature composed of a very great number 

 of small bony tubercles. Along* the median line an irregular series of 

 tubercles with the base enlarged, almost quadrilateral, the points directed 

 backward ; a tubercle on the shoulder girdle on each side of the median 

 line. Five papillie in the mouth. Jaws strongly arched. Yery young, 

 almost smooth. Uniform brown. [Burner il.) Florida to Brazil. 



{Ilaia tHhercuJata Laceprdo, Hist. Poiss. ii, 103: Tnj(/on tuberculaia Dumdril, Elasmo- 

 Ijraiicb. G05: Tryrjon tuberculata Guuther, viii, 480.) 



65. D. sabiBiMS (Le Snciir) Goodc & Bean. 



Disk ovai-rhomboidal, scarcely longer than broad, the anterior bor- 

 ders lightly concave, united by rounded angles to the posterior borders, 

 which are longer and a little convex; snout projecting; tail twice as 

 long as the body ; upper part of the head rough with small spines ; on 

 the middle of the back a row of tubercles commencing behind the head 

 and prolonged on the base of the tail ; 5 buccal papillaj ; two spines on 

 each side of the shoulder girdle ; tail rough, with two short, low cutane- 

 ous folds; mouth strongly arched. Color uniform yellowish brown. 

 {Dumeril) " Distinguished from J), ccntrurus by the shape of the disk, 

 the shape of the caudal spine, and the wing-like membranes on the 

 tail" {Goode in lit.). Perhaps xlentical with the preceding. 



{Tnjgon sfffci/m Le Sueur, Jouru. Ac. Nat. Sci. Phila. 1824, iv, 109: Tn/gon sabina 

 Dumeril, Hist. Nat. Poiss. i, 607: Tnjgon tuberculata Giinther, viii, 480, part.) 



Family XXII.— MYLIOBATID^. 



[The Uagle Rays.) 



Disk broad; the pectoral fins not continued to the end of the snoii't^ 

 but ceasing on the sides of the head and reappearing in front of the 

 snout as one or two fleshy protuberances (cephalic fins), whicli are sup- 

 ported by fin rays. Tail very long and slender, whip-like, with a single 

 dorsal fin near its root, behind which is usually a strong, retrorsely 

 serrated spine. Nasal valves forming a rectangular flap, with the pos- 

 terior margin free, attached by a frenum to the upper jaw. Skull less 

 depressed than usual among rays, its surface raised so that the eyes and 

 spiracles are lateral in position. Teeth hexangular, large, flat, tessel- 

 lated, the middle ones usually broader than the others. Ovoviviparous. 

 No differentiated spines on the pectorals in the males, the sexes being 

 similar. Ventrals not emnrginate. Genera 3 ; species about 20. Large 

 Bull. Nat. Mus. No. IG 4 



