332 Mr. C. T. Regan oti the Fishes of the 



B. Soft dorsal and anal scaly at the base. 



D. XIII 10. A. Ill 7. Caudal peduncle | as 



lon<r as d^ep 1?. guianensis. 



D. XIV-XVI 9-11. A. Ill 8-10. Caudal pe- 

 duncle 5— J as long as deep 1'3. portaJegrensis. 



II. Prue operculum scaly ^. 



A. Two series of scales on the cheek and one series on the prte- 



operculum. 



1. 23-2(5 scales in a longitudinal series. 



D. XIII-XIV 7-10. A. Ill 8. Dorsal and anal 



fins scaleless 14. dorsijera. 



D. XIV-XV 9-10. A. Ill 7. Soft dorsal and 



anal scaly at the base lo. Thayeri. 



D. XVI 9-10. A. Ill 7 10. favilabris. 



2. 28-29 scales in a longitudinal series. D. XVI 10-11. A. Ill 8. 



17. frenifera. 



B. Three scries of scales on the cheek and one or two series on the 



prfeoperculiim. D. XV 10-11. A. Ill 9-11. 



18. Maro7iii. 



1. Acara tetrnmerus. 



Acara tetramerus, Ileck. Ann. Mus. Wien, ii. 1840, p. 341 ; Giinth. 



Cat. Fish. iv. p. 277 (1802) : Steiiid. Sitzb. Ak. Wien, Ixxi. 187o, 



p. 60 ; Cope, Proc. Ac. Philad. 1872, p. 2.5o, and Proc. Am. Phil. 



Soc. xxxiii. 1894, p. 106; Pellegr. M^m. Sec. Zool. France, xvi. 



1903, p. 171 (1904). 

 Acara viridk, Ileck. t. c. p. 343 ; Giinth, t. c. p. 280. 

 Acara diademn, Heck. t. c. p. 344. 

 Arara paUidus, Heck. t. c. p. 347; Giinth. t. c. p. 280. 

 Chroniys punctaia, Casteln. Aiiim. Am. Sud, Poiss. p. 13, pi. viii. fig. 1 



(1855). 

 Chromys nniocellaln, Casteln. t. c. p. 15, pi. vi. fig. 1. 

 Acara vittata (uon Heck.), Giinth. t. c. p. 279. 

 Acara uniocellata, Giinth. t. c. p. 281. 

 Astronotus tetrnmerus, Eigenm. it Eigenm Proc. U.S. Nat. Mus. xiv. 



1891, p. 68; Eigenm. & Bray, Ann. Ac. N. York, vii. 1894, p. 617. 

 JEquidens tetraynerus, Eigenm. & Kennedy, Proc. Ac. Philad. 1903, 



p. 634. 



Depth of body 2-2^ in the length, length of head 2|-3. 

 Snout shorter than postorbital part of head. Diameter of 

 eye 2§-3| in the length of head, interorl)ital width 2f-2f . 

 Depth of prreorbital ^-1^ the diameter of eye. Maxillary 

 extei\ding about to the vertical from anterior margin of eye; 

 jaws equal anteriorly ; fold of the lower lip not continuous ; 

 cheek with 3 or 4- series of scahjs ; praeoperculum scaleless ; 

 5 or 6 gill-rakers on the lower part of anterior arch. 

 Scales 25-27 ^,, 3 or 2^ between lateral line ai\d anterior 



' '^ A. frvnitcra. 



