28 CALIFORNIA ACADEMY OF SCIENCES. 



length, the spine stout and smooth, 1-WlH in head. Dis- 

 tance of the adipose fin behind the dorsal about equal 

 to the length of the adipose fin or one-half longer, 5-6 

 in the length. 



Caudal emarginate with numerous, short, accessory 

 basal rays. 



Free margin of the anal straight or slightly convex, 

 the fifth ray highest, about 1^ in the head, rapidly de- 

 creasing to the last ray, which is about half the height 

 of the fifth. 



Ventrals inserted under the last dorsal ray l|-2 in the 

 head. 



Pectoral spine very strong and with a leathery pro- 

 longation; height of the spinous portion 11-2 in the 

 head; outer margin of the spine smooth, inner margin 

 with strong recurved teeth along its entire length. 



Bases of all the fins, lower part of head, suborbital 

 region and opercles and a median line on the back pur- 

 plish; rest of body and fins yellowish, and under the 

 lens dark. 



Head4-4J; depth 4^-5^-; Br. 7; D.I, 7 or 8; A. 9-12. 



Eight specimens .12-. 20 m. Rivers of Santiago. 



Family III. SILURID.E. 



<CSiluroides Cuvier, Regno Animal, iii, 199, 1817. 



<:^Siliiroidei Bleeker, Nederl. Tijdschr. Dierk. i, 1863. 



<iSiluridcv Giinther, Cat. Fish. Brit. Mus. v, 1, 1864. 



y-Siluridce Gill, Arrangement of Families of Fishes, 

 19, 1872. 



<^Siluridte Eigenm. & Eigenm. Am. Nat. July, 1888. 



This, the largest family of the Nematognathi, is most 

 widely distributed, having representatives in all the 

 continents but Australia. It reaches its greatest devel- 

 opment in the tropics of America. 



The position and size of the dorsal, the free air blad- 



