CERATOBATIS. 453 



MOBULA HYPOSTOMA. 



Plate 38; Plate 54, fig. 6 (pelvis); Plate 57, fig. 6 (heart); Plate 59, fig. 7-8 (gills); Plate 



75 (skeleton). 



Cephalopterus hyposlomus Bancroft, 1831, Proc. Zool. soc. London, pt. 1, p. 134; 1834, Zool. journ. 5, 



p. 411. 

 Cephaloptcra olfersii Muller, 1834, Abh. Akad. wiss. Berlin, p. 311; 1835, Anat. Myxin., p. 12, 247; 



MiJLLER & Henlb, 1841, Plagios., p. 185; Dumeril, 1865, Elasm., p. 657. 

 Dicerobatis olfersii Gunth., 1870, Cat. fishes Brit, mus., 8, p. 497. 

 Dicerobalus olfersii Garman, 1888, Bull. M. C. Z., 17, p. 105, pi. 52, 53. 

 Aodon hyposlomus Jord. & Everm., 1896, Bull. 47, U. S. nat. mus., p. 92. 

 Mobula olfersi Coles, 1910, Bull. Amer. mus. nat. hist., 28, p. 341; Pellegrin, 1912, Bull. Soc. philom. 



ser. 10, 4, p. 5 extra. 



Irregular diamond shaped, nearly twice as wide as long, angles acute. 

 Pectorals nearly straight in front, concave behind. Teeth small, broad, rounded 

 or with one to several points on the inward edge, in || rows on a specimen 

 thirty-nine inches in width, Plate 38, fig. 5 and 6. Muller and Henle give the 

 number of rows on their specimen as about 80. Teeth bands occupying about 

 half the width of the jaws. Tail longer than the body, without a spine. Back 

 smooth, large individuals rough posteriorly on the body, and on the tail. Origin 

 of dorsal fin little behind the vent; extremity little in front of the ends of the 

 ventrals. Teeth increasing in the numbers of rows with age, and in width of 

 bands. 



Brown on the back; white beneath. 



Brasil to New York. 



MOBULA ROCHEBRUNEI. 



Cephaloptcra rochebrunei Vaillant, 1879, Bull. Soc. philom., p. 171; Rochebrune, 1882, Acta Soc. 

 Linn. Bord., 36, p. 58, pi. 1, f. 1-2. 



According to the description and the figure this form agrees in all respects 

 except coloration with M. hypostoma, of which it may be a variety. 



Deep blue; with reddish on the frontal region, in a longitudinal band behind 

 the head along the middle of the back, and on dorsal, ventrals, and tail. Rows 

 of teeth 50, occupying about half the width of the jaws. 



Off northwestern Africa. 



Ceratobatis. 



Ceralobalis Boulenger, 1897, Ann. mag. nat. hist., scr. 6, 20, p. 227. 



"Like Dicerobatis Blainv., but teeth restricted to the upper jaw." 

 A subgenus of Mobula. 



