132 OSTAEIOPHTSl. 



pectoral spine, which has the inner edge serrated and measures = to -j of the len,2;t]i of the fin or about 4 

 the lenj^th of head. Ventrals inserted behind the last ray of dorsal, extending ■?- to j of the distance 

 from their base to the origin of anal. Caudal deeply notched, the lower lobe rounded. Least depth of 

 caudal peduncle about i the length of head or of the distance from anal to base of caudal. Erownish ; 

 usually a blackish lateral stripe ; fins dusky, the dorsal with a pale band near the base. 



Hab. Costa Eica, Shivures (//. Pitticr) ; Panama i 3._'\Yestern Ecuador (Bosenljcrff). 



Here described from four specimens, measuring 200 to 280 mm. in total length. 

 Probably records of tliis species from Southern Mexico refer to H. (juatemalevsiti. 



6. Rlianidia petenensis. (Tab. XXII. fig. l.) 



Pimdodus petenensis, Giiuth. Cat. Fisli. v. p. l.'2G (1864') '. 



Rhamdiu petenensis, Jurd. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 153 '^ 



Depth of body 5,7 in the length, length of head 4;'. Ercadth of head 1? in the length, length of snout 2|, 

 diameter of eye b},, interorbital width 3. Jaws nearly equal anteriorly ; width of mouth ij the width of 

 head. Maxillary barbel extending to origin of adipose fin. Head covered with smooth skin ; occi[iital 

 process extending about h of the distance from its base to the origin of dorsal. S gill-rakers on the 

 lower part of anterior arch. Dorsal I 6; spine slender, fin rounded. Length of adipose flu 21- in 

 the length of the fish. Anal 12. Humeral process extending to middle of pectoral spine, which is 

 # to :f the length of the fin and nearly 4 the length of head. Ventrals inserted behind the last dorsal 

 ray, extending 3- of the distance from their base to the origin of anal. Caudal deeply notched. Least 

 depth of caudal peduncle 1| in the length of head and Ik in the distance from anal to base of caudal. 

 Lrownish ; an indistinct dark lateral stripe ; dorsal dusky, with a pale band near the base. 



Huh. Guatemala, Lake Peten 1 [Salvin). 



Plere described from the type, a specimen measuring 200 mm. in total length. 



7. Rliamdia guatemalensis. 



Pinieloi/iis ijaalemalensis, Giintli. Cat. Fish. v. p. 122 (1864) '. 



Rlia India guatemalensis, .lord. & Evcrm. Bull. U.S. Nat. Mus. xlvii. 1896, p. I.j2'. 



Rhamdia oaxaca, Meek, Publ. Columljiaii Mus., Zool. v. 1901, p. 20, t. 5 '. 



Depth of body -A to 0,; in the length, length of head Si to 4?-. Breadrb of head li to \\ in its length, length 

 of snout 2^- to ;i, diameter of eye 5 to 7^, interorbital width 2'i to ;U. Lower jaw nearly as Ion" as 

 the ujipcr : width of mouth ;| to 5- the width of head. Maxillary barbel extending to origin or middle 

 of adip(jsc fin. Head covered with smootfi skin ; occipital process extending nearly \ the distance from 

 its base to the origin of dorsal. 5 to 7 gill-rakers on the lower part of anterior arch. Dorsal I G ; siiinc 

 slender, tin rounded. Length of adipose fin 2-' to 3 in the length of the fish. Anal 11-1.'!, wlien laid 

 balk ri aching the vertical from the end of adipose fin. Humeral i)rocess extending about to middle of 

 pi'ctoral spine, which has the inner edge serrated and measures from less than ". to more than J'- the 

 lengtli of (he fin, or --i- to h the length of head. Ventrals inserted behind the vertical from last rav of 

 dorsal, extending 'i to •} of the distance fronr their base to the origin of anal. Caudal deeply notched 

 tiio lower lobe rounded. Least depth of caudal peduncle 2 to 2i in tho length of head or l.-J to 2 in the 

 distance from anal to base of caudal. Brownish ; usually a blackish lateral stripe ; fins usually more or 

 less dusky, the dorsal with an indistinct pale band near the base. 



Hal. .Southern Me.\ico, Rio IManco s, Rio Papaloapam ■', Tequcsixtlan in Oaxnca 

 {('Jail 010); British Honduras, Stann Creek {Rohertson) ; Guatemala, Huamuehali 



(-S'«/r/»). 



