210 Mr. C. T. Regan— ^ Revision 



B. Spots smaller and more numerous. 



1. Operculum \ as broad as deep 7. agassizli, 



2. Operculum more than \ as broad as deep. 



a. Dorsal spine shorter than longest soft rays. 



8-13. multimacu/ahis, julii, elegans, trilineatus, 

 punctatus, rainmndi, 



b. Dorsal spine rarely a little shorter than first soft ray. 



Dorsal spine longer than head 14. ai-mntns. 



Dorsal spine a little shorter than head lo. poh/stictus. 



Dorsal spine as loug as head 16. melcmistius. 



0. A black arrow-shaped spot at base of caudal fin. 



17. hastatns. 



D. Dark undulating longitudinal stripes 18. undulutus. 



E. A dark lateral band ; fins immaculate. 



1. Depth of suborbital not more than its distance from upper lip. 

 a. Depth of body 3|- to 3^ in the length . . 19. melanutcenia. 

 h. Depth of body 2^ to 3 in the length. 



Snout not shorter than postorbital part of head ; 



edge of dorsal fin somewhat convex 20. ceneits. 



Snout shorter than postorbital part of head ; edge 



of dorsal fin straight 21. nattereri. 



2. Depth of suborbital twice its distance from the upper lip. 



22. macrosteus. 



3. Suborbital extending from eye to upper lip. 



23. egiies. 



1. Corydoras treltlii, 

 Steind. Anz. Akad. Wien, 1906, p. 478. 



Depth of body equal to or a little more than length of 

 head, which is 2\ to 3 in the length. Snout 11- to 1\, 

 diameter of eye 4^ to 5, iiiterorbital width 3 to 3| in the 

 lengtli of head. Barbels reaching gill-opening. Dorsal I 8 ; 

 adipose fin preceded by 4 or 5 median scutes. Anal I 7. 

 Pectoral spine a little shorter than that of dorsal. Scutes 23/21. 

 Brownish above, yellowish below ; a dark grey lateral stripe ; 

 caudal usually with dark upper and lower margins, rarely 

 with a few spots on the middle rays. 



R. Parnaliyba. 



Total length 66 mm. 



2. Corydoras kronel. 



Ribeiro, A Lavoura, xi. no. 5, 1907, p. 189, fig. ; Steind. Anz. Akad. 



Wien,1910, p. 61. 

 Corydoras eigenmanni, R. von Ihering, Rev. Mus. Paulist. i. 1907, 



p. 35. 



Depth of body about equal to length of head, 3^ to 4 in 



