48 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
twice as long as body, subcylindrical, without a trace of keel above, roughened with small tubercles, 
with an irregular series of broad-based conical tubercles on each side; a long narrow cutaneous 
expansion below has its origin opposite the beginning of the spine, and terminates in a keel which 
continues to the extremity; a pair of large, compressed, erect tubercles immediately in front of caudal 
spine, and a single- one over the middle of the pelvic arch; these suggest a continuous series in larger 
specimens; 3 larger elongated tubercles with points directed backward — similar to those of hastala — 
occupy the middle of the shoulder-girdle; mouth curved, 6 (5-6 ?) papilla- at the bottom; 2~ of these 
are in the middle in front where usually there is but one. 
Color light olive) probably greenish in life, white below. Distinguished from Dasyatis centrum by 
the prominent snout, the shape of the tubercles on the middle of the back, and the narrowness of the 
posterior portion of the disk. 
Length of body 16, length of tail 35.3, and width of pectorals 20.5 inches. Collected at the 
Hawaiian Islands by Andrew Garrett. (Garman. ) 
Trygon lata Garman, Bull. Mus. Comp. Zool., VI, October, 1880, 170, Hawaiian Islands. 
Dasibatis lata, Jordan & Gilbert, Bull. U. S. Nat. Mus., No. 10, 67, 1883 (after Garman). 
16. Dasyatis hawaiensis Jenkins. Plated, fig. 1. 
Snout 4.5 to base of tail; eye about 3.67 in interorbital space; interorbital space broader than 
length of snout; width of mouth 2.3 in interorbital space; internasal space 2 in head. 
Body more or less circular, the width of the disk a little greater than its length and its greatest 
width a little in advance of the center of its length; head very broad, the anterior margins of the disk 
very slightly undulated; snout very broad, only slightly pointed; eye small; mouth very small, very 
slightly undulate; teeth very small, in about 30 very oblique series in the upper jaw; upper buccal 
flap with a broad fringe; floor of mouth with 5 tentacles; nostrils large, the border of the broad nasal 
flap with a fine fringe; interorbital space broad, more or less flattened; gill-openings of about equal 
length, the fifth about level with the greatest width of the fish; body more or less smooth; tail without 
any asperities; caudal spine broad, flattened, the sides strongly serrate; pores more or less obsolete; 
tail about 1.67 longer than disk and with a somewhat broad cutaneous fold both above and below, the 
latter beginning below base of dorsal spine; pectorals rounded obtusely; ventrals very broad, the 
width of their bases a little less than their height or length. 
Color in alcohol, dark brown above with the edges of the disk pale, or dull, and the lower surface 
creamy white with margins of the disk soiled or dirty brown; posterior margins of pectorals and 
ventrals with their edges below very narrowly white. 
The specimen upon which this description is based was obtained at Honolulu by Dr. Jenkins. 
It has a total length of 16.5 inches (5.87 inches to base of tail; tail 10.63 inches) and is the only 
example of the species thus far known from the Hawaiian Islands. It is allied to Dasyatis dipterura 
Jordan & Gilbert, from San Diego Bay. 
Dasyatis hawaiensis Jenkins, Bull. U. S. Fish Comm., XXII, 1902 (Sept. 23, 1903), 420, pi. I, Honolulu. 
Family IX. AETOBATIDtE. — T he Eagle Rays. 
Disk broad; pectoral fins not continued to end of snout, but ceasing on sides of head and reappear- 
ing in front of snout as one or 2 fleshy protuberances (cephalic fins), which are supported by fin 
rays; tail very long, slender, and 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 posterior 
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; skin smooth; no differentiated spines on the 
pectorals in the males, the sexes being similar; ventrals not emarginate. Genera 3; species about 20. 
Large sting-rays inhabiting warm seas, feeding chiefly on mollusks, which they crush with their large 
grinding teeth. Ovoviviparous. 
