128 OSTAEIOPHTSI. 



5. Arius multiradiatus. 



Arms multiradiatus, Giinth, Cat. Fish. v. p. 173 (1864) '. 



Tachijsurus multiradiatus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 13.2'. 

 Taehysurus emmelane (Gilb.), Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1900, p. 2786 ' ; Gilb. & 

 Starks, Mem. Calif. Ac. Sci. iv. 1904, p. 31, t. 6 '. 



Depth of body 5 in the length, length of head 3^. Breadth of head 1| in its length, diameter of eye 7. 

 Pontanel produced into a groove which nearly reaches the parieto-ocoipital ; occipital process without 

 distinct keel, broader than long, with concave sides and slightly emarginate apex ; dorsal shield small, 

 subcrescentic. Width of mouth ^ the width of head ; prasmaxillar}' band of teeth 4 times as long as 

 broad; teeth on the palate obtusely conical, in two small, well-separated, subovate patches; maxillary 

 barbel extending to basal part of pectoral. 11 gill-rakers on the lower part of anterior arch. Dorsal 

 I 7 ; spine | the length of head ; adipose fin shorter than the dorsal. Anal 27. Pectoral spine | the 

 length of head, with the inner edge rather strongly serrated. 



Hah. Panama ^ ^ ■* (Boucard). 



Here described from a specimen measuring 230 mm. in total length. 



6. Arius hypophtlialmus. 



Ai-ius hypophthalmus, Steind. Sitzungsb. Ak. Wien, Ixxii. 1876, p. 581, t. 10'. 

 Tachisurus gulosus, Eigenm. & Eigenm. Occ. Papers Calif. Ac. Sci. i. 1890, p. 93 '". 

 Cathorops hypophthalmus, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 133 ^ 

 Cathorops gulosus, Jord. & Everm. 1. c.'. 



Hah. Panama ^ ^ s 4_ 



4. PtHAMDIA, Bleek., 1858. 

 Rhamdia, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 149. 



Body elongate. Snout not greatly produced; mouth terminal or subtcrminal ; jaws with villiform teeth in 

 bands ; palate toothless ; nostrils remote from each other ; no nasal barbels ; barbels G ; occipital 

 process not extending to the dorsal tin. Dorsal fin with a slender flexible spine and 5 to 8 branched 

 rays ; adipose fin long ; anal short or of moderate length ; ventral fins 6-rayed. 



Numerous species, from Mexico to the La Plata. 



Synopsis of the Mexican and Central-American Species *. 



I. Caudal tin deeply notched, the middle rays not more than i the length of the longest. 



A. Width of mouth ? to \ the width of head ; pectoral spine i to ;| the length of head. 

 Occipital process as broad as long, extending J of the distance from its base to 



the origin of dorsal ; body rather deep (depth l.l to 5 in the length) . . 1, parryi. 

 Occipital process much longer than broad, extending ^ of the distance from its 



base to the origin of dorsal; body rather slender (depth about 6 in the 



length) ; first branched ray of dorsal the longest . 2. motaguensis. 



'"- The original description of P. hrachypterus, Cope (Trans. Am. Phil. Soc. 1866, p. 404), from Orizaba, is 

 insufficient, but Fowler's re-description of the type (in Meek, Publ. Columbian Mus., Zool. v. 1904, p. 21) 

 shows that this species is probably not distinct from P. yuateniaJensis. 



