154 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
42. Gerres mexicanus Steindachner. Mexican Mojarra. 
The collection contains four specimens of this 1 rare species, all from Teapa, which is the type 
locality. They range in length from 5.75 to 10 inches. Head 3.3; depth 2.5; eye 3 in small specimens, 
3.5 to 3.67 in larger ones; snout 3.25 to 3.67; scales 6-46 to 50-10 or 11; D. ix, 10 or 11; A. nr, 8 or 9. 
Body compressed, rhomboidal in form, covered with large smooth scales; back much elevated; lateraj 
line continuous, concurrent with the elevated back, beginning on a line with upper margin of eye; 
head flat, a slight depression above the eye; mouth moderate, upper jaw very protractile; maxillary 
extending to about middle of eye, its length about 2.5 in head, exposed portion oblong, width 2 in 
length; preorbital and preopercle serrate; premaxillary groove entirely free from scales; second dorsal 
spine strong and long, head contained in it 1.3 times; second anal spine stronger but shorter than second 
dorsal, 1.67 in second dorsal; outer edge of dorsal fin forming a deep reentrant angle; anal same 
shape as dorsal but smaller; pectoral reaching beyond tips of ventrals in large specimens, not so far in 
small ones, its length equaling head. 
General color, bluish-silvery above, silvery below; very distinct dark longitudinal lines along the 
middle of each row of scales; dorsal, caudal, and anal fins dusky; the margin of dorsal black; a dark 
supraorbital spot; pectoral and ventral pale. 
43. Menticirrhus littoralis (Holbrook). Surf Whiting. 
One specimen, 11.75 inches long, from Progreso. Head 4.5; depth 4.5; eye 7.3; snout 3.25; inter- 
orbital 4.75; D. x-i, 24; A. i, 7; scales 8-60-16. This fish has not heretofore been recorded south of 
Texas. It is worth noting that the more southern specimens have smaller scales, as noted in another 
member of the same family, Aplodinotus grunniens, found at Montecristo. 
44. Aplodinotus grunniens Bafinesque. Fresh-water Drum; Gaspergou. 
One specimen, 13 inches long, from the Rio Usumacinta at Montecristo. Head 3.5; depth 3.2; 
eye 4.67; snout 4; maxillary 2.75; mandible 2.5; interorbital 3.5; preorbital 6.5; scales 9-60-12, counted 
from vent to lateral line, and from first dorsal spine to and including lateral line; D. x, 31; A. ii, 7; 
longest dorsal spine 2.16 in head; longest anal spine 1.67 in head; pectoral 1 in head. Body oblong; 
back much elevated and compressed; profile long, steep, and straight; head slightly compressed; mouth 
moderate, subinferior, low; maxillary reaching middle of eye; teeth in villiform bands, outer scarcely 
enlarged; lower pharyngeals completely united; gillrakers short, thickish, 6-j-14; preopercle serrated; 
snout bluntish; dorsal spines strong and high, a scaly sheath at base of spines, the two dorsals 
connected; caudal doubly truncate; second anal spine unusually large and strong; scales rather thin 
and deep, the series somewhat oblique, crowded anteriorly. 
