74 Fretp Museum or Natura. History — Zoétocy, Vor. X. 
length 3.3 to 3.5 in head; diameter of eye 3.4 to 3.9; snout 2.2 to 2.4; 
preorbital 3.2 to 3.7, postorbital 2.5 to 2.7; pectoral 1.1 to 1.2; ventral 
.7 to .9; base of anal .g to 1.0. Caudal peduncle 2.2 to 2.4; spinous 
dorsal rather high, the 6th spine 1.9 to 2.2 in head; the last dorsal spine 
1.5 to 1.6; last anal spine 1.5 to 1.7; gill rakers short, 9, dorsal, anal and 
ventrals with their rays produced; caudal fin emarginate; soft dorsal 
with scales on interradial membranes. 
Color olivaceous, sides with 6 or 7 indistinct cross bars. <A lon- 
gitudinal dark lateral band about as wide as eye, a large black spot on 
side and a smaller one at base of caudal; vertical fins usually with many 
black spots. 
This species resembles C. balieatum but differs in having/a shorter 
head and smaller eye, and longer dorsal and anal spines. 
Neetroplus fluviatilis sp. nov. 
Type No. 7585, F. M. N. H.; length 116 mm.; Costa Rica River near 
Guapilis, Costa Rica. 
Head 3.3; depth 2.6; D. XVII or XVIII, 9; A. VI, 6; scales 34. 
Body elongate, compressed, profile very convex; mouth small, sub- 
inferior, the lower jaw the shorter, teeth compressed; preorbital very 
deep, equaling the postorbital, 2.6 in head; eye 3.9; snout 2.2; inter- 
orbital very convex; scales on breast, nape, and along each side of dorsal 
fin, very small; pectoral fins 1.4 in head; ventrals slightly longer than 
head; dorsal fin low, the last spine 2.2 in head, the 6th spine 3.1, last 
anal spine 2.2; base of anal 1.2 in head; caudal peduncle 2.2 in head, gill 
rakers very blunt, 3+6; caudal fin rounded. 
Color dark olivaceous, 6 or 7 faint dark bars on the sides. Known 
from the type and one other specimen (105 mm.) from Costa Rica River 
near Guapilis. | 
Gobiesox costaricensis sp nov. 
Type No. 7577, F. M. N. H.; length 62 mm.; Zent, Costa Rica, 
Head 2.7; depth 5.6; D. 6; A. 4. 
Body broad, depressed anteriosio: teeth incisor, their edges entire; 
dorsal and anal fins small, the latter under posterior half of the former. 
Head broader than long, width of mouth about } width of head. 
Color olivaceous, with 4 or 5 darker bars on back extending on 
sides. Caudal barred, a black spot:at base of anterior rays of dorsal. 
The following are measurements (mm.) of the specimens obtained: 
