208 CALIFORNIA ACADEMY OF SCIENCES. 



b. Groove of fontanel continued to midway between eye and occipital 

 process; a band of cirri extending to the end of the groove, the tips of 

 the cirri on a level with the surface of the head; a faint transverse 

 groove at base of occipital process, 

 c. Maxillary barbels extending to or somewhat beyond dorsal fin. 



d. Brown above, abruptly white on sides; sides with 10-12 dark 

 cross bars bordered anteriorly by shorter light bars; sometimes 

 dark spots along the lower margin of the sides; dorsal, caudal, 

 tips of ventrals and tips of anal with a few dark spots; head 

 rarely with similar spots. Maxillaries reaching tip of dorsal. 



fasciatum 152. 



dd. Black above gradually shading into white below; lateral bars of 

 the abdominal region extending to the edge of the bell-y; a series 

 of large black spots along the sides; all the fins, the adipose in- 

 cluded, conspicuously spotted with dark. Maxillary barbel 

 reaching to origin of dorsal. fasciatum nigricans 152a. 



cc. Maxillary barbels not reaching to the dorsal. 



e. Vertical bars as in fasciatum, enlarged at the lower termination, 

 those on the abdominal portion of the body broken up into spots; 

 a lateral series of very large spots. Maxillary barbels reaching to 

 the edge of the opercle. fasciatum bre.vifile 152b. 



ee. Back and sides with narrow dark wavy lines which extend to 

 the edge of the belly; fins variable, plain or spotted; head with 

 small spots. Maxillary barbels not reaching to the dorsal. 



fasciatum intermedium 152c. 



eee. Back and sides with narrow dark lines which form coarse re- 

 ticulations; a series of spots along the lower part of the sides. 

 Maxillary barbels reaching little beyond pectoral. 



fasciatum reticulatum 152d. 



bb. Groove of the fontanel deep, continued to the base of the occipital 

 process; a band of long cirri extending to midway between the eye 

 and occipital process; the tips of the cirri not on a level with the sur- 

 face of the bone bordering the fontanel; a deep transverse groove at 

 base of occipital process and a shorter one extending outward and back- 

 ward. Dark above, light below; about 16 curving cross bands half as 

 wide as the eye, more or less joined below by an irregular lateral 

 band; dorsal, caudal and anal with conspicuous spots; adipose fin 

 barred and spotted with brown; head unspotted. tigrinum 153. 



aa. Body with round black spots which occasionally are confluent into 

 lines; groove of the fontanel not continued to the occipital process. 

 Maxillary barbel extending beyond preopercle. coruscans 154. 



152, Pseudoplatystoma fasciatum. 



Silurus fasciatus Linnaeus, Syst. Nat. ed. xii, i, 505, 176G; id. ed. xiii, 

 1359, 1788; Bonaterre, Enc. Ichthyol. 154, 252, 1788; Bloch, 

 Ausland. Fische, part 8, 30, pi. 366, 1794; Bloch & Schneider, 

 Syst. Ichthyol. 382, 1801. 



