48 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY— IV. 
Caudal spine times width of mouth. Spiracles very large. Color 
nearly uniform brownish. L. 8 feet. Cape Cod to Florida ; common. 
(Perhaps includes more than one species.) 
(liaia centriira Mitcliill, Trans. Lit. & Phil. Soc. N. Y. i, 47U : Pastinaca hmtata De- 
kay, New York Fauna, Fishes, 373: Tryijon hastata Giiuther, viii, 476.) 
** Upper and lower caudal folds well developed. (Dasyatis.) 
62. D. sayi (Le Sueur) Goode & Beau. 
Disk rhomboidal, a little broader than long, the muzzle moderately 
prominent. Width of mouth contained about 2^ times in the length of 
the snout. Tail with two well-developed folds, the lower fold consider- 
ably the larger, both smaller than in Z). clipternrus. Tail slender, 
prickly, nearly twice as long as the disk : its sitine extremely long ; its 
length 2i times the width of the mouth. Skin smooth in the. young, 
becoming roughish with age. Several rather strong recurved spines 
along the middle line of the back. Spiracles moderate. Buccal papillm 
5 (7). Color brownish. South Atlantic States to Brazil. 
{Raja say Le Sueur, .Touru. Ac. Nat. Sci. Pliila. 1817, 42: Trygon sayi Diimdril, 
Ela.smobrauch. 603: Trygon pastinaca -p&xt Giiuther, viii, 478.) 
63. D. dipteriiriis Jordan & Gilbert. 
Disk rhomboid, slightly broader than long, anterior margins nearly 
straight, meeting anteriorly in a very obtuse angle ; posterior margins 
curved; lateral angles rounded; tail nearly half longer than the disk, 
with a conspicuous cutaneous fold below and a smaller but evident one 
above; jaws considerably arched ; buccal papillteS; teeth -|J. Young 
perfectly smooth. Adult with a row of low but rather stout tubercles 
on the median line of the scaimlar region and two others on the humeral 
region. Tail with small prickles. Caudal spine long, its length nearly 
3 times the width of the mouth. Color bluish brown, nearly plain. L. 
0 feet or more. Bay of San Diego, California; abundant. 
(Dasyhatis dipterurus Jordau & Gilbert, Proc. U. S. Nat. Mus. 1880, 31.) 
64. D. tuberciiliitiis (Lacdp.) Goode & Beau. 
Disk rhomboidal, a little broader than long; anterior borders scarcely 
concave, the posterior almost straight ; external angles rounded ; muz- 
zle pointed ; tail below with a cutaneous fold, higher and longer than 
the upper fold, covered for its posterior two-thirds with small ossifica- 
tions ; tail nearly 2^ times length of disk. All the middle of the upper 
surface of the body, from the posterior region of the head to the base 
