HOPLIAS.— PIA.BUCINA. 167 



1. HOPLIAS. 



Macrodoii (non Schinz), ]Mull. & Trosch. Ilor. Iclithyol. iii. p. 6 (1815) ; Giiutli. Cat. Fish. v. p. 281 



(1864) ; Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 330. 

 Hvplias, Gill, Proc. "U.S. Nat. Mus. xxvi. 1903, p. 1016. 



This genus comprises two species only, viz. ff. microlepis fi'om Panama and Western 

 Ecuador, and the widely-distributed South-American //. trahira, Spix, which ranges 

 from the Magdalena to the La Plata and which differs from its congener in having a 

 broader head and somewhat larger scales. 



1. Hoplias microlepis. (Tab. XXVI. fig. I.) 



Macrodon microlepis, Giiath. Cat. Fish. v. p. 282 (1864) '. 



Depth of bod}- 3| to 5 in the length, length of head ^\ to 3i. Snout longer than eye, the diameter of which 

 is 6 to 8 in the length of head ; interorbital width 3| to 34 in the length of head. Mouth wide, the 

 maxillary extending beyond the vertical from the posterior edge of cj'e ; teeth acutely conical, in a single 

 series in the jaws, with some strong canines ; teetli on the palatines in bands and on the vomer in two 

 separate patches. 42 to 45 scales in a longitudinal series, between middle of dorsal and lateral line, 

 5 or 6 between lateral line and root of ventral fin, 11 across the back of the tail from one lateral line to 

 the other. Dorsal 13-14, nearly in the middle of tho length of the fish ; edge straight or slightly convex. 

 Anal 10-11, rounded. Pectorals and ventrals of moderate length, rounded. Caudal rounded. Olivaceous, 

 marbled with brownish, the marking sometimes forming a longitudinal baud and vertical bars; fins with 

 dark undulating stripes or series of spots. 



Hab. Panama, Kio Chagres i {l)ow, Salvin). — Western Ecuador [Festa). 



Here described from several specimens, including the types of the species, measuring 

 up to 300 mm. in total length. 



2. PIABUCINA. 



Piabiwina, Cuv, & Val. Hist. Nat. Poiss. xxii. p. 161 (1849); Giintli. Cat. Fish. v. p. 311 (1864); 

 Jord. &Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 332. 



This genus resembles Ilojdias in general form, in the structure and position of the 

 fins, except that the caudal is emarginate instead of rounded, and in the absence of a 

 fontanel in the cranial roof. 



About six species are known, from Panama, Ecuador, Colombia, Venezuela, and 

 Guiana. 



1. Piabucina panamensis. 



Piabucina ]}anamensis, Gill, Proc. Ac. Philad. 1876, p. 336 '; Jord. & Everm. Bull. U.S. Nat. Mus. 



xlvii. 1896, p. 333 \ 



Depth of body 4 in the length. Dorsal 10. Anal 12. 30 scales in a longitudinal series, A dark longi- 

 tudinal band on the middle of the side ; a dark spot on the base of the dorsal fin. 



Ilab. Panama, Ilio Tripoli i. 



This species may be identical with P. eryfltrinoides, C. & V., from Venezuela. 



