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BULLETIN OF THE BUREAU OF FISHERIES 
The devilfish was not taken during the present investigation. This species and a related 
species ( Mobula hypostomus) , not as yet recorded from Chesapeake Bay, may be recognized at once 
by two hornlike appendages in front of the head, known as the cephalic or rostral fins. The 
present species differs from its relative in the entire absence of teeth on the upper jaw. 
The devilfish, according to Gill (1910, p. 167), feeds chiefly on small crustaceans and young or 
small fish. This species, like the spotted eagle ray, also has the habit of leaping above the surface 
of the water, but it is not definitely known whether this habit is correlated with the delivery of the 
young, as reported by Coles (1910, p. 340) and Gudger (1914, p. 301) in the case of the spotted 
eagle ray. The devilfish has only one young at a time, according to Gill (1910, p. 172) and others. 
No information concerning the occurrence of this species in Chesapeake Bay was obtained 
during the present investigation. It was unknown to the fishermen who were questioned. The 
species is included in this work because of the statement by Uhler and Lugger (1876) — namely, 
that it is occasionally seen near the entrance to Chesapeake Bay. 
Habitat. — Warm waters of both coasts of America. On the eastern coast its range extends 
northward to Block Island, R. I. 
Chesapeake localities. — (a) Previous record: “* * * near the entrance to Chesapeake 
Bay” (Uhler and Lugger, 1876). (6) Specimens in the present collections: None. 
Class PISCES. True fishes 
Superorder GANOIDEI 
Order GLANIOSTOMI 
Family XVI. — ACIPENSERID/E. The sturgeons 
Body elongate, cylindrical; skeleton cartilaginous; body imperfectly covered with bony plates 
or shields; head with similar large plates; snout produced with four flexible barbies hanging from 
its lower surface; mouth underneath head, small, protractile, suckerlike; teeth wanting; eyes small; 
tail heterocercal ; air bladder large. A single genus of these large fishes is known from Chesapeake 
Bay 
20. Genus ACIPENSER Linnasus. The sturgeons 
Bony plates not confluent, one series on back and a lateral and abdominal series on each side; 
ventral plates often deciduous; snout more or less conical, depressed; spiracles over eye; gill rakers 
small, pointed. 
KEY TO THE SPECIES 
«. Space between dorsal and lateral shields with stellate plates of rather large size, in 5 to 10 series; 
top of head with a smooth area in young and deeply concave; snout long, acute, rather narrow 
at base; D. 30 to 44; A. 23 to 30 oxyrhynchus, p. 72 
aa. Space between dorsal and lateral shields with minute spinules, in very many series; top of head 
without a smooth area in young and less deeply concave; snout short, proportionately broader 
at base; D. 33; A. 19 to 22 brevirostrum, p. 76 
27. Acipenser oxyrhynchus Mitchill. “Sturgeon”; Sharp-nosed sturgeon. 
Acipenser oxyrhynchus Mitchill, Trans., Lit. and Philo. Soc., N. Y., I, 1815, p. 462; New York. Uhler and Lugger, 1876, ed. 
l, p. 183, ed. II, p. 155; Bean, 1883, p. 367. 
Acipenser sticrio Jordan and Evermann, 1896-1900, p. 105, PI. XX, fig. 45; Smith and Bean, 1899, p. 181; Fowler, 1912, p. 51. 
The sturgeon is a fish of variable characters. The following description has been compiled 
from published accounts, both of American and of European fish, and from an examination of speci- 
mens made by us. 
Head 3.7 to 5; depth 7 to 10; D. 30 to 44; A. 23 to 30. Most authors give the dorsal rays 
between 30 and 40, but Ryder (1890, p. 235), who made an extensive study of the sturgeons of the 
Delaware River, counted 40 to 44 on the fish examined by him. The number of anal rays given by 
most authors is 23 to 27, but Ryder (loc. cit.) found 26 to 30. The body is elongate, somewhat 
hexagonal, tapering gradually to base of caudal; head flattened above; snout 2 to 3 in head, vari- 
