FISHES OP THE FAMILY LORICARIID^E. 245 



Key to the Species. 

 I. Fold of the upper lip with median prolongation .... 1. C. loborhynchus Tschudi. 



II. Fold of the upper lip without median prolongation. 



A. Interorbital width 2§- 2f times in the length of head. 

 Diameter of eye 9 times in the length of head (in specimens of 



65 mm.) 2. C. maculatus Rgn. 



Diameter of eye 6 times in the length of head (in a specimen of 



100 mm.) 3. C.marcapata Rgn. 



B. Interorbital width 3-3£ times in the length of head. Dorsal with I 8 rays, the last £-| 



as long as the first. 



1. Length of base of dorsal equal to its distance from posterior part of spine of adipose 



fin. 



a. Anal with I 4 rays; 5-10 interopercular spines ; caudal peduncle 2-2 J times as long 



as deep. 

 Depth of body 4^ times in its length, head H-lf times as long as 



deep 4. C. brevis Rgn. 



Depth of body 5-5 R times in its length, head 1|— 2 times as long 



as deep 5. C. tacsanowskii Stdr. 



b. Anal with I 5 (rarely I 4) rays ; 1-5 interopercular spines. 

 a. Depth of body 4J-5 times in its length, head H-lf 



times as long as deep, caudal peduncle twice as 



long as deep 6. C. dermorhynchus Blgr. 



/3. Depth of body about 5| times in its length, head lf-2 times as long as deep, 

 caudal peduncle 2^-2^ times as long as deep. 



1 or 2 interopercular spines 7. C.Jischeri Stdr. 



4 or 5 interopercular spines ; length of snout 1 \ times in that of 



the head 8. C. stannii Ltkn. 



4 or 5 interopercular spines ; length of snout lf-2 times in that of 



the head 9. C. guairensis Stdr. 



2. Length of base of dorsal equal to its distance from the 



spine of the adipose fin ; caudal peduncle 2|-3 times 



as long as deep 10. C. marginatus Rgn. 



3. Length of base of dorsal only a little less than its 



distance from the caudal 11. C branickii Stdr. 



C. Interorbital width 3|-3§ times in the length of head. Dorsal with I 8 (rarely I 7 

 or I 9) rays, the last | as long as the first. 

 Intcroperculum with 6-10 spines. A. I 3-4. Caudal peduncle 



2-2J times as long as deep 12. C. anomalus Rgn. 



Iuteroperculum with 4-5 spines. A. I 5. Caudal peduncle 2|-2| 



times as long as deep 13. C. thomsoni Rgn. 



■ D. Interorbital width 3£ times in the length of head. 



D. I 7. A. I 4 14. C. nudirostris Ltkn. 



