DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 483 
Numerous examples, up to 34 inches long, were collected by Mr. Salvin in the Lakes 
of Duefas and Amatitlan, and in the Rio Guacalate. This species occurs also in 
Western Ecuador. Figure 3 represents the male, and fig. 4 the female. 
252 FuNDULUS PACHYCEPHALUS. (Plate LXXXIV. fig. 6.) 
Giinth. Fish. vi. p. 321. 
This species is closely allied to F. guatemalensis, but has a thicker head and 
smaller eye. 
Dris-14, “ASL: Vi6> Li lat: 35. IL. transv. 112. 
The height of the body, taken on the level of the base of the pectoral, is contained 
thrice and one-fifth or thrice and four-fifths in the total length (without caudal). Head 
very thick and broad, its length being contained thrice and one-third in the total. 
Interorbital space very broad, slightly convex, its width being one-half of the length 
of the head. Snout broad, obtuse, with the lower jaw slightly projecting beyond the 
upper; mandible longer than the eye. The diameter of the eye is less than the length 
of the snout, one-fourth of that of the head, and one-half of the width of the inter- 
orbital space. The origin of the dorsal fin is midway between the extremity of the 
caudal and the anterior or posterior margin of the orbit, and corresponds to the six- 
teenth scale of the lateral line. The first anal ray corresponds to the third of the 
dorsal. Dorsal and anal fins subquadrangular, of moderate height, the latter fin being 
scarcely higher than long. Caudal fin subtruncate. Brownish above and on the sides, 
each scale darker on the tip; an indistinct dark band along the middle of the tail. 
Fins immaculate, anal with the lower margin whitish. 
Three males, 24 inches long, were obtained by Mr. Salvin in the Lake of Atitlan. 
254, GAMBUSIA NICARAGUENSIS. (Plate LX XXII. fig. 3, fem.) 
Giinth. Fish. vi. p. 336. 
Dy Sag At Oe oulatec Os li. tansy nse 
The height of the body is contained thrice and a third in the total length (without 
caudal), the length of the head thrice and two-thirds. Snout broad, subspatulate, with 
the lower jaw projecting beyond the upper. The diameter of the eye is a little more 
than the length of snout, one-third of that of the head, and three-fifths of the width of 
the interorbital space. In the female the origin of the dorsal fin is somewhat nearer to 
the extremity of the caudal than to the end of the snout, and opposite to the last ray 
of the anal fin. Pectoral fins not quite reaching as far backwards as the ventrals, 
which terminate immediately in front of the anal fin. Free portion of the tail rather 
short, the length of the base of the anal fin being one-half of its distance from the 
caudal fin. Brownish olive above, sometimes with series of black dots along the rows 
DB) 
3u 2 
