EiGENMANN: The Serrasalmin.« AND Mylin.^. 265 



X. Genus Mylosoma Eigenmann. 

 31. Mylosoma ocellatum Eigenmann, sp. nov.? 



5629 C. M. Type. 44 mm. and 5630 C. M. Paratypes, nineteen, 



largest 48 mm. Villa Hays, Paraguay, April 13, 1909. 



These specimens may prove to be the young of M. albiscopiis. 

 Head 3; depth 1.30 in the largest, 1.5 in some of the smaller; D. 16- 

 19; A. 33-36; abdominal serrae 39-48; eye 2.5 in the head; 1.33 in 

 interorbital; very compressed, deep; profile steep, slightly concave 

 at the occiput. Ventral profile pendulous; predorsal area naked. 

 Ventral spines simple thorns (in the young only?) present both in 

 front and behind ventrals. About half of the cheek is naked. Teeth 

 of the premaxillarj' close together. Gill-rakers 12 + 13. 



Origin of dorsal nearly equidistant, from tip of snout and base of 

 caudal, its highest ray equals head less opercle; depth of caudal 

 peduncle equal to the length of the eye; origin of anal about equidistant 

 from the snout with the adipose; margin of anal convex, the highest 

 ray little if any more than snout and eye. Ventral small, its origin 

 equidistant from snout with the posterior part of the dorsal, its tip 

 reaching anal; pectorals small, about equal to ventrals, not nearly reach- 

 ing ventrals. 



Scales small, lateral line developed (in young?) to below dorsal or 

 shorter; anal with a few scales along its base only. 



Caudal hyaline; dorsal hyaline or with blackish; anal blackish; a 

 black ocellus below the middle of the dorsal; sides with alternating 

 light and dark cross-bands, the third light cross-band being con- 

 tinuous with the light about the ocellus. 



32. Mylosoma aureus (Spix). 



5721 a-h. C. M. Two, 75-77 mm. Berlin, Rio Mamore, Sept. 15, 

 1909. Haseman. 



5722 a. C. M. One, 90 mm. Santarem, Dec. 12, 1909. Haseman. 



5723 a-c. C. M. Three, 147-170 mm. San Antonio, Rio Madeira, 

 November 2, 1909. Haseman. 



Head 4-4^, depth if-i^^, D. 17 or 18; A. 32-34. 

 Serrae 43-49. 



The following specimens are probably the young of aureus. 

 5631 and 5632 C. M. Two, 22 and 29 mm. Santarem, Dec. 9, 1909. 

 Haseman. 



