J)R. GUNTHEK ON THE FISHES OF CENTRAL AMBEICA. 483 



Numerous examples, up to 3| inches long, were collected by Mr. Salvin in the Lakes 

 of Dueiias 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. 



D. 13-14. A. 15. V. 6. L. lat. 35. L. transv. 12. 



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, 2^ inches long, were obtained by Mr. Salvin in the Lake of Atitlan. 



254. Gambusia nicaraguensis. (Plate LXXXII. fig. 3, fem.) 

 Gunth. Fish. vi. p. 336. 



D. 8. A. 10. L. lat. 29. L. transv. 8. 

 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 row.s 



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