210 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
d. Dorsal fin without distinct light or dark margin; head more than one-third 
trunk; teeth entire. 
e. Body dark brown, vaguely reticulated with narrow pale streaks and spots ; 
belly with crosswise streaks of dark; a dark line on each side of base 
of anal, with short cross-branches; a black blotch on gill-opening; 
teeth strong ;.-\.\./220sreee oes sae ee 22 ese bee eae eee Morpax.* 
ee. Body uniform chestnut-brown ; no dark spot at gill-opening ; sides of man- 
dible with about 18 teeth ; body rather stout .......-.-- CASTANEA.t 
dd. Dorsal fin with a black margin, its edge narrowly white; anal white-edged ; 
head less than one-third trunk; sides of mandible with about 13 
teeth; body slender; size'small (?)-.-.-.:.-2---2vseeeeee VERRILLI.t 
aa. Dorsal not beginning betore gill-opening; teeth mostly biserial. 
f. Color plain brown; dorsal beginning nearly over gill-opening; inner 
teeth of sides of upper jaw long, slender, close-set ; anterior teeth 
strong, serrate behind; mouth short; about 20 teeth on each side of 
lower jaw ; size small\(#). soe s cess cas ccs eee teas see PANAMENSIS.$ 
Sf. Color blackish, with rather distant yellow spots, confluent on the 
throat; dorsal beginning at end of first third of body (?). Fresh 
waters (exclusively?) Gsi2 = 3: 4oo cet eceeticcce sce Jae AQU2-DULCIS. |] 
INDIANA UNIVERSITY, July 11, 1883. 
DESCRIPTION OF A NEW SPECIES OF RHINOBATUS (RBHINOBATUS 
GLAUCOSTIGMA) FROM MAZATELAN, MEXICO, 
By DAVID S. JORDAN and CHARLES H. GILBERT. 
Rhinobatus glaucostigma sp. nov. 
Khinobatus productus Streets, Bull. U. S. Nat. Mus., vii, 1877, 55. (Exel. Syn.; 
not of Ayres. San Bartholomé Bay, Lower California.) 
Rhinobatus leucorhynchus Jordan & Gilbert, Bull. U. S. Fish Comm., 1882, 105. 
(Mazatlan; no descr.; not of Giinther.) 
Allied to the California species (Rhinobatus productus Ayres), and to 
the Panama species (Rhinobatus leucorhynchus Giinther), but with the 
snout shorter than in either and the coloration different. | 
Disk comparatively long and narrow, the snout produced, but not 
acutely pointed, the anterior margins being very nearly straight. Great- 
est width of disk slightly less than its length to end of base of pectorals; 
length of snout from eye 24 in length of disk ; interorbital width 34 in 
snout, a little less than length of eye and spiracle. Spiracle large, rather 
smaller than eye, with two conspicuous folds on its posterior border. 
Width of body opposite posterior part of base of ventrals, a little less 
* Murena mordax Ayres, Proc. Cal. Acad. Nat. Sci., 1859, 30. Point Conception to 
Cerros Island. 
t Sidera castanea Jor. & Gilb., Proc. U. S. Nat. Mus., 1883. Mazatlan (Gilbert). 
} Sidera verrilli Jor. & Gilb., Proc. U. 8. Nat. Mus., 1882. Panama (Bradley). 
§Murena panamensis Steindachner, Ichth. Beitr., v, 1876, 19. Panama (Steind.); 
Pearl Islands (Bradley). 
|| Mureena aque-dulcis, Hayden’s Rept. Geol. Surv. Montana for 1871, 474, 1872. Rio 
Grande at San José de Costa Rica (Cope). This species is unknown to us. 
