262 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



cc. Anal 30-41. 



/. Lateral line 40-50. 



j. A silvery lateral band ending in a black caudal spot, sometimes two lateral 

 spots in front ; maxillary very short, without teeth, 2 in the eye ; depth 

 2J-3 ; head4-4j ; eye 2j-2f in head; D. 1 1, behind ventrals ; A. 35-40. 

 Lat. line 44-47. 8. festce (Boulenger). 



jj. A black band extends from base of caudal fin along its middle rays ; max- 

 illary extending to eye, its length at least f the length of the eye, with- 

 out teeth ; eye 2^-3 in head ; depth 2\-2\ ; head 4 ; A. 34-40 ; scales 8 

 or 9-40 to 50-8 or 9 ; last dorsal over first anal ray. 



9. brevirostris (Giinther). 

 jjj. Maxillary with two small teeth, equal to eye in length ; eye 2.6-2.8 in 

 head ; depth 2.7-3 I head 3.5-3.6 ; scales 8-39 to 45-6 or 7 ; A. 28 or 

 29 ; a dark caudal spot, not extending to end of middle rays. 



38. emperador, which see- 



jjjj. Caudal and humeral spots generally absent ; origin of dorsal over ventral ; 



interorbital wider than eye ; depth 3 ; head 4 ; scales 9-40 to 46-10 ; 



A. 26-31. 37. Cordova, which see. 



ii. Lateral line less than 40, except sometimes in abramis and bimaailatus. 



k. Anal rays 36 or fewer, rarely as many as 39 in bimaculatus, maxillary with 

 a few teeth or none. 



/. Depth more than three in the length, the form long and slender ; max- 

 illary without teeth. 

 VI. Humeral and caudal spots present, anal and ventral with broad 

 red margins ; eye 3§ in the head, much smaller than the con- 

 vex interorbital. Maxillary extending to anterior margin of 

 eye. A. 27—3 1 ; scales 7—36—7. 27. Immilis, which see. 



vim. No caudal or humeral spots ; a silvery lateral band, most dis- 

 tinct posteriorly; head 3I ; eye 2\ in the head. A. 30; 

 scales 5-35-3. Maxillary toothless. 10. astictns (Ulrey). 

 //. Depth 3 in the length. Middle rays of caudal covered by a broad 

 band which extends to the margin of the fin and bordered above and 

 below by yellow ; a silvery lateral band ; a humeral spot ; head not 4 

 in the length. A. 27-35. Scales 7-38-7. Maxillaiy with a single 

 tooth. 23. tanuirus, which sec. 



///. Depth less than 3 in the length ; a distinct caudal spot. 



n. No humeral spot ; depth 2^-2| ; eye 3|-4 in the head ; maxillary 

 with 0-3 teeth, extending considerably beyond anterior margin 

 of eye ; a conspicuous black band on the caudal peduncle, be- 

 coming wedge-shaped on the caudal. A. 29-31. Scales 7 or 

 8-37 or 38-6. II. vtaxinius (Steindachner). 



nil. A distinct humeral spot. 



o. Maxillary long ; head 3.75 ; depth 2.75 ; eye 3 in the head, 

 I ^ in snout, equal to interorbital ; maxillary without teeth ; 

 a black humeral spot, a silvery lateral band, becoming 

 black on the tail and extending on the caudal ; origin of 



