FISHES OF CHESAPEAKE BAY 
67 
21. Dasyatis sabina (Le Sueur). Stingray. 
Trygon sabina Le Sueur, Journ., Ac. Nat. Sci., Phila., IV, 1824, p. 109, PI. IV. 
Dasyatis sabina Jordan and Evermann, 1896-1900, p. 84, PL XIV, figs. 36 and 36a. 
Dasybatus sabinus Garman, 1913, p. 397. 
Disk little, if any, broader than long, the anterolateral margins distinctly concave in front 
of eye, meeting at an angle of about 90°, the posterolateral margins broadly and evenly convex, the 
outer angles of disk very broadly convex, the posterior angle much more sharply rounded, the length 
of disk 1 to 1.05 in its width; head to first gill slit 2.65 to 2.75 in width of disk; distance from tip of 
snout to vent 1.15 to 1.2; snout rather pointed, its length 1.4 to 1.5 in head; preoral length of snout 
1.5 to 1.6; width of mouth 3.45 to 3.95; interorbital (bone) 3.8 to 4.3; eye 4 to 4.35 in snout; spiracles 
immediately behind the eyes elliptical, the longest diameter equal to length of eye; nasoral groove 
extending to mouth; teeth arranged in pavement, similar in both jaws and in the sexes; three large 
papillae at base of lower jaw and two small ones at each side; skin almost perfectly smooth in our 
youngest examples with only a few spines on median line of back, the largest individual with a row 
of prominent, compressed spines on median line of back, extending from the occiput nearly to base 
of caudal spine, and two similar spines on each shoulder; the tail long and slender, depressed anteri- 
orly, round and whiplike posteriorly, bearing one or two long, sharply-serrated spines; rather short 
cutaneous folds behind the spine, both above and below the tail, the lower fold a little broader than 
the upper; tail 1.6 to 1.65 in total length; ventral fins extending well beyond the disk, their posterior 
margins rounded, the outer angles sharper than the inner ones. 
Color brownish on back, the winglike expansions paler; white underneath. The upper fin 
fold on the tail yellowish brown, the lower buff. 
This ray is represented by four specimens — three males, respectively, 190, 215, and 275 milli- 
meters (7)4, 8)4, and 10^ inches) broad, and one female 185 millimeters (7)4 inches) broad. We 
also have the tail and the teeth of another specimen which measured 16 inches in width, evidently 
belonging to this species. This ray is rather closely related to D. say, from which it may be dis- 
tinguished by the more pointed snout, the deeper concavity opposite the eyes, in the outline of the 
disk, and by the paler color of the fin folds on the tail. 
The stomachs of the specimens at hand all contained fragments of crustaceans. 
This sting ray apparently reaches a moderate size. The specimens previously mentioned, 
measuring 16 inches in width, appears to be among the largest taken to date. The species, although 
previously not recorded from Chesapeake Bay, probably is not rare there. It was not recognized 
in the field as distinct from D. say, and the fishermen do not distinguish it. The specimens were 
seclected at random from various catches, with the result that 5 of this species and 8 of D. say 
were preserved. 
Habitat . — Previously recorded from North Carolina to Brazil. The range is now extended 
to Chesapeake Bay. The species enters fresh water. 
Chesapeake localities. — (a) Previous records: None. ( b ) Specimens in present collection: 
Lower York River, Va., collecting seines, July Sand October 6, 1921, and Ocean View, Va., com- 
mercial and collecting seines, October 2, 6, and 16, 1922. 
15. Genus PTEROPLATEA Muller and Henle 
Disk much broader than long, very strongly depressed, the anterior angle obtuse, the lateral 
angles acute; tail slender, shorter than body, with or without a serrated spine and without a fin. 
This skate reaches a rather large size. A single species inhabits the Atlantic coast. 
22. Pteroplatea micrura (Schneider). Sand skate; Butterfly ray. 
Raia micrura Schneider in Bloch, Syst. Ichth., 1801, p. 360; “Surinamo.” 
Pteroplatea maclura Bean, 1891, p. 94; Jordan and Evermann, 1896-1900, p. 86. 
Pteroplatea micrura Garman. 1913, p. 414, pi. 23, figs. 3 and 4. 
Disk much broader than long, anterolateral margins convex opposite the head, the median 
portion of the margins broadly concave, the outer angles rounded, the posterolateral margins 
broadly convex, length of disk 1.65 to 1.85 in the width; head to first gill slit 5.6 to 6.8 in width of 
disk; distance from snout to vent 1.95 to 2.1; snout at its tip projecting very slightly beyond the 
outline of the disk, its length 1.5 to 1.8 in head; preoral length of snout 1.37 to 1.62; width of 
