68 silurid^;. 



length (without caudal). Barbels thin, those of the maxillae scarcely 

 longer than the head. (Agass.) 

 Northern Brazil. 



2. Hypophthalmus longifilis. 

 Cue. $ Val. xv. p. 230. 



B. 14. D. 1/6. A. 64-68. P. 1/15. V. 6. 



The length of the head is one-fourth of the total length (without , 

 caudal). Maxillary barbels longer than the head, extending beyond 

 the dorsal in the young ; mandibulary barbels with a narrow fringe 

 along their inner margin. Dorsal spine much more feeble and shorter 

 than the slender pectoral spine, the length of which is one-half of 

 that of the head. 



Guiana. 



a. Adult. Demerara. Purchased of Mr. Scrivener. 



b-c. Adult and half-grown : stuffed. Demerara. Purchased of Mr. 



Scrivener. 

 d. Half-grown. Surinam. Purchased of Mr. Frank. 



3. Hypophthalmus marginatus. 



Hypophthalmus marginatus, Cue. ty Val. xv. p. 225. pi. 439. 

 Notophthalmus marginatus, Hyrtl, Denkschr. Akad. Wiss. Wien, xvi. 

 1859, p. 17. 



B. 14. D. 1/6. A. 63-68. P. 1/14. V. 6. 



The length of the head is two-sevenths of the total (without 

 caudal). Maxillary barbels longer than the head, not extending on 

 to the end of the pectoral ;. mandibulary barbels compressed, but 

 not fringed. Dorsal spine feeble, half as high as the body ; pectoral 

 spine slender. Top of the dorsal and hinder margin of the caudal 

 black. {Vol.) 



Cayenne and Surinam. 



4. Hypophthalmus fimbriatus. 



Kner, Sitzgsber. Wien. Acad. 1858, xxvi. p. 444. fig. 30. 

 B. 13-14. D. 1/6. A. 67-68. P. 17. V. 6. 



The length of the head is one-fourth of the total (without caudal). 

 The maxillary barbels have a narrow fringe, and extend on to the 

 end of the pectoral ; mandibulary barbels broadly fringed, the an- 

 terior being nearly half as long as the entire fish. Dorsal fin low, 

 the length of its feeble spine being two-fifths of the height of the 

 body. Pectoral spine flexible. {Kner.) 



Bio Negro. 



