SOME FRESH-WATER FISHES FROM BUENOS AIRES. 109 



39 cms. The scales are iridescent, greenish above, and yellow below the lateral line, 

 while each bears a distinct cross-mark on its surface. 



Micropogon undulatus (Linnaeus). 



Perca undulata, Linnaeus, Syst. Nat., 12th ed., 1766. 



Micropogon undulatus, Guuther, Chall. Rep. on Shore Fishes (Monte Video). 



Giinther, Ann. Mag. Nat. Hist., 5th ser., 1880 (Rio de la Plata). 



Gunther, B.M. Cat., ii p. 211. 

 ,, Guv. and Val. (New Orleans). 



,, Perugia, Ann. Mus. Civ. Stor. Nat. Geneva, x., 1890 (Monte Video). 



,, Berg, Anal. Mus. Nac. Buenos Aires, iv., 2nd ser., 1895 (Bahia 



Blanco, Mar de Plata, Monte Video, Maldonado). 



Evermann and Kendal, Proc. U.S. Nat. Mus., xxxi., 1907 (Argentine). 



,, ,, Berg, Ann. Mus. Nac. Buenos Aires, iv., 2nd ser., i., 1895 (Emboco- 



dura del Rio de la Plata, Monte Video). 



7 



D. X. I, 28. A. II. 8. Lat, line 52 + 3 caudal. Lat. transv. . 



15 



One specimen was caught on the line in Rio de la Plata, while the other was taken 

 from the Government Dry Dock at Buenos Aires. The respective lengths are 27 and 

 31 cms. The comparative measurements of the Scotia specimens agree with those 

 given by EVERMANN and KENDAL in Proc. U.S. Nat. Mus., xxxi., where the specimens 

 are of the same size. The colour is silvery . There are dark grey spots on back, while 

 below the lateral line these have a tendency towards stria ticm. . .. 



Rhamphichthys blochii (Bl. and Schn.) (PI. fig. 2). 



Gymnotus rostratus, Bl. and Schn., 522, t. 106. 

 Rhamphichthys blochii, Kaup, Apod., p. 133, fig. 9. 



rostratus, Mull, and Trosch. 



Carapus rostratus, Cuv., ii. p. 357. 

 Rhamphichthys blochii, Gunther, B.M. Cat., viii. 5, 1860 (Para). 



KAUP attributes the original of this species to BLOCK, but comments on the imper- 

 fection of the description. The number of anal rays is 365, as in the Scotia specimen, 

 though BLOCH gave 292. Anus accompanied by a genital papilla which lies behind 

 the vertical line through the posterior margin of the eye. Snout tubiform and slightly 

 more than half the length of the head. Small round spots on the head and body. 

 Irregular black lines and spots on the fins. Between the anal fin and the lateral line 

 runs an interrupted series of oblique bars. 



Length, 296 mms. 



