130 OSTAEIOPHYSI. 



2. Humeral process extending beyond middle of pectoral spine. 



Adipose fin f the length of the fish ; anal of 13 rays 15. salviiri. 



Adipose fin -I the length of the fish ; anal of 15 rays IG. poli/caiilta\ 



III. Caudal fin slightly notched, nearly truncate. 



INlaxillary barbel extending to middle of pectoral fin ; adipose fin r, the 



length of the fish 17. roz/crsL 



INlaxillary barbel extending to ventral fin; adipose fin y the length of 



the fish 18. laticaiida. 



1. Rhamdia parryi. 



Ii/ia7)idia parri/i, Eigcnm. Proc. Calif. Acad. Sci. (2) i. 1888, p. 130'; Jord. & Everm. Bull. U.S. 



Nat. i\Ius. xlvii. 1896, p. 153'. 



Depth of Ijody 4] to .j in the length, length of head 4^ to 4i. Breadth of liead 1| in its length. Diameter 

 of eye 5 in the length of head, 2 in the length of snout, 1| in the intcrorbital width. Lower jaw shorter 

 than the upper : width of mouth Sij to 3 in the length of head (about f to 5 the width of head). 

 Maxillary barbel extending to or beyond the dorsal fin. Head covered with smooth skin ; occipital 

 jjiocess as broad as long, extending ^ of the distance from its base to the origin of dorsal. Dorsal 1 6 ; 

 spine slender. Length of adipose fin 3 to 3i in the length of the fish. Anal 12-14. Pectoral spine 

 slightlj' more than J the length of head. Lower caudal lobe rounded. Brownish ; a blackish lateral 

 stripe. 



Jfab. Mexico, Ilio Zanalenco in Chiapas ^. 

 Apparently allied to B. motagicensis. 



2. Rhamdia motaguensis. (Tab. XX. fig. 1.) 



I'imelodus motaguensis, Giinth. Cat. Fish. v. p. 127 (1864) '. 



Rhamdia motafjuens'ts, Jord. & Evcrm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 151 '. 



Depth of body Hj to Gj in the length, length of head 5:| to o^. Breadth of head 1,] to 1>] i]i its length, 

 length of snout 21 to 2;,', diameter of eye 5 to 6, interorbital width 3 to 3;}. Lower jaw shorter than the 

 upper ; width of snout ^ the width of head, ilaxillary barbel extending to middle of dorsal (adult) or 

 nearly to adipose fin (young). Head covered witli smooth skin ; occipital process extending 'f^ of the 

 distance from its base to the origin of dorsal. 8 or 9 gill-rakers on the lower part of the anterior arch. 

 Dorsal I 6: spine slender; first branched ray the longest. Length of adipose fin .'^J in the length of the 

 fish. Anal V.',. Humeral process not extending to middle of pectoral spine, which is about ^ the length 

 of the fin and \ to |; the length of head. Yentrals inserted behind the last dorsal ray, extending i to = of 

 the distance from their base to the origin of anal. Caudal deeply notched. Least depth of caudal 

 picdunclc ] Ji in tlic lenglli of head and 14- to 2 in the distance from anal to base of caudal. Brownisli ; 

 dorsal dusky, witli a pale band near the base. 



Hall. British IIoNDUi;.\,s, Stann Creek {RoherUon) ; Guatemala, llio Motao-ua i 

 {_8alvhi). 



Here desciibed from two specimens, the type, 210 mm. in total length, and one (jf 

 130 mm., from Stann Creek. 



3. Rhamdia nicaraguensis. (Tab. XX. fig. 2.) 



Plmcbdus nicarugiiemis, Giinth. Cat. Eish. v. p. 125 (1864) '. 



liliamdla nicaru(juensis, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 152". 



