84 Bulletin 47, United States National Museum. 



borders convex; outer and hinder angles rounded. Ventrals almost 

 entirely covered by the pectorals, their hinder margins convex. Tail 

 more than li times the length of the disk, low-keeled on the upper side, 

 a long, broad, membranous expansion below, roughened with small asperi- 

 ties ; 1 or more serrated spines. Body smooth in young ; very old with 

 scattered small asperities ; a row of narrow compressed tubercles along 

 the middle of the back and on the base of the tail; the points of these 

 tubercles are depressed and directed backward. On each shoulder, par- 

 allel with the median row, there is a shorter row, the length of which 

 varies according to age. Mouth with 3 papilhe. Jaws with more curva- 

 ture than those of centrura and less than those of sabina ; young without 

 tubercles. Color bluish or olivaceous brown, pale below. AVest Indies 

 to Brazil, north to Florida, the original description from a specimen taken 

 in Rhode Island, (hastatus, armed with a spear.) 



Trijgon hasUita, DeKav, N. Y. Fauna: Fishes, 373, pi. 65, fig. 214, ?, 1842, Rhode Island. 

 Trijgon hastata, Storer, Syn. Fish. N. Amer., 261, 1846. 

 Trijgon haslata, Dl'm£ril, Elasmobranches, 592, 1870. 

 Dasibatis hastata, Jordan & Gilbert, Synopsis, 70, 1883. 



123, DASTATIS GYMNURA, (MUller). 



Disk quadrangular, a little wider than long. Snout produced, sharp- 

 pointed; anterior and posterior margins nearly straight, the anterior 

 curved near the outer angle to meet the posterior, and the latter curved 

 near the hinder angle to meet the inner. Tail nearly 3 times the length 

 of the disk, with a slight ridge above aud a narrow cutaneous expansion 

 below, roughened with small spines similar to those on the head; a row 

 of elongated tubercles on the back and anterior portion of tail, and 1 

 or more smaller ones on each shoulder; the posterior tubercles of the 

 median row much elongated, so as to resemble the spines. Mouth much 

 undulated, with 3 papilhe; teeth small, unequal. Young without tuber- 

 cles ; as the animal grows older a few scattered asperities appear on the 

 head; still later these increase in number and size to such an extent as to 

 cover the head and back with a heavy coat of mail made up of closely set 

 flattened scales ; the tubercles of the back cease growing as the scales 

 enlarge, aud ultimately there is little distinction between them; usually 

 the tubercle on the middle of the pectoral arch is larger; those on the tail 

 continue to increase in size with age. Disk wider than long ; tail 3 times 

 length of disk. Color yellowish to olivaceous biown, darkening with age. 

 (Garman.) Surinam to Bra7il, recorded from Grenada by Giiuther, other- 

 wise not known from the West Indies, (yvfxvoc, naked; ovpa, tail.) 

 Itaie luhercuh'e, LAofcptDE, ii, 106, pi. 4, fig. 1, 1800, Cayenne. 



Itaia tuberculala, SilAW, Genl. Zool., v, 290,1804, after LacepC-de, not of Bonnatorre, 1788. 

 Tnjgon gymnnra, J. MOller, Ermann's Reise uin die Erde, 25, taf. 13, 1830, Brazil. 

 Trijgon osteosticta, J. Muli.er, I. c, 25, taf. 14, 1830, Brazil. 

 Trygon tuberculata, Gi'NTHER, Cat., viii, 480, 1870. 

 Dasibatm iKbcrcuhita, Jordan & Gilbert, Synojisis, 66,1883. 



124. DASYATIS SABINA, (Le Sueur). 



Disk subcircular. Snout produced, bluut. Anterior margins of the 

 pectorals concave near the snout, becoming convex toward the broadly 



