9. PETENIA. 301 



ocellus, edged with white, on the upper part of the root of the 

 caudal. 



Rio Negro, Guaporc, Araguay. 



a. Fine specimen. From the Collection of the Zoological Society. 

 h. Adult : skin. Tropical America. 



9. PETENIA. 



Body compressed, oblong, covered with ctenoid scales of moderate 

 size. Dorsal spines numerous, anal spines more than four ; the soft 

 dorsal scaleless. Teeth in a band, small, conical. Anterior pro- 

 minences of the first branchial arch short, compressed, distant. Cleft 

 of the mouth wide ; jaws veiy protractile. Scales on the cheeks small. 

 The origin of the ventral falls vertically below that of the dorsal. 



Guatemala. 



1. Petenia splendida. 

 B. 5. D. ||. A. ■^. L. lat. 41. L. transv. 6/17. 



Scales on the cheek in about seven series. Greenish, shining 

 golden ; head, body, and vertical fins with black dots. A series of 

 six or seven large round black spots along the middle of the side, 

 the last spot being edged with white, and situated on the upper half 

 of the root of the caudal. 



Lake Peten. 



a-c. Fine specimens. From the Collection of Messrs. Salvin and 

 Godman. 



Description. — The height of the body is contained thrice in the 

 total length (without caudal), the length of the head twice and two- 

 thirds. Head longer than high ; snout compressed, triangular, \vith 

 the lower jaw very prominent. The jaws are extremely protractile, 

 so that the snout is not much shorter than the head when the jaws 

 are protracted. The processes of the intermaxillaries extend back- 

 wards to the nape of the neck, and the length of the mandibles is 

 three-quarters of that of the head. The greater portion of the max- 

 illary is not covered by the praeorbital, and it extends beyond the 

 vertical from the centre of the orbit. Each jaw is armed with a band 

 of villiform teeth, the outer series containing rather larger conical 

 teeth. Prseorbital narrower than the orbit, the diameter of which 

 is one-sixth or one-seventh of the length of the head. Interorbital 

 space very convex, as wide as, or wider than, the orbit. 



The gill-membranes are united below the throat, and not attached 

 to the isthmus. The first branchial arch has thii-tcen anterior pro- 

 minences. 



The dorsal fin commences in the vertical from the root of the 

 pectoral ; its spines are of moderate length and strength ; they 

 increase in length to the seventh, the length of which is two-ninths 

 of that of the head ; the posterior spines, again, are a little longer 

 than the middle ones. The soft dorsal and anal are rather elevated, 



