344 Fretp Museum or NATURAL History — Zodxoey, VoL. X. 
band at base of dorsal. A large black blotch present at base of caudal, 
and most specimens with a black blotch on middle of side under tip of 
pectoral. An occasional specimen also has many small dark spots on 
sides. Fins plain translucent, or dusky; the vertical fins often with 
small dark spots. 
There are 237 specimens, ranging from 20 to 250 mm. in length, in 
the present collection. All are from the lower Chagres and its tribu- 
taries. It was frequently found abundant in very brackish water, and 
in Panama its range seems to be limited to the brackish and sluggish 
streams of the Atlantic slope. 
The parents appear to guard their young for quite some time after 
hatching. On one occasion it was noticed that two large fishes, evidently 
of this species, were hovering very closely to numerous small ones, at 
a place where the water was quite shallow. An attempt was made to 
surround them with a seine. However, the adults by their very quick 
movement made their escape. A large number of young was taken. 
Only a few minutes after the seine was hauled the two large fishes reap- 
peared and a second attempt at capturing them failed. The young 
were all of about equal size, ranging from 20 to 24 mm. in length. 
Habitat: Lake Yzabal, Guatemala, south to Rio Chagres, Panama. 
75. Cichlasoma tuyrense Meek & Hildebrand. 
Heros margaritifer var. Steindachner, Denksch. K. Ak. Wiss. Wien, 
XLI, 1879, 161 (Rio Mamoni, Chepo). 
Cichlasoma tuyrense Meek & Hildebrand, Field Mus. Nat. Hist. Pub., 
Zool. Ser., X, 1913, 89 (Rio Tuyra, Boca de Cupe, Panama). 
Head 2.75 to 3.45; depth 1.77 to 2.1; D. XVI to XVIII, usually 
XVII, rx or 12; A. VI or rarely VII, 8 or 9; scales 34 to 41. 
Body deep, compressed; anterior profile nearly straight in young, 
strongly convex in adult; no nuchal hump; head deep; snout moderately 
pointed, 2.2 to 3.4 in head; eye 3.33 to 4.3; mouth rather small, terminal, 
slightly oblique; maxillary failing to reach anterior margin of eye, 2.8 
to 3.7 in head; the lips not thickened, the lower one not free at middle; 
teeth in the jaws pointed, in bands, the outer one somewhat enlarged; 
gill-membranes broadly connected across isthmus; gill-rakers short, 
about 8 on lower limb of first arch; scales rather small, weakly ctenoid, 
6 or 7 rows between lateral line and middle of base of dorsal; lateral line 
interrupted under soft portion of dorsal, reappearing on the fifth row of 
scales below its original course; origin of dorsal over posterior margin 
of opercle, the spines strong, the last one 1.86 to 2.33 in head; the soft 
portion with small scales at base, pointed and reaching well past base of 
caudal in adult; caudal fin scaly at base, its posterior margin strongly 
Se aaa 
