Cichlid Genera Retroculii^, Geoplm^^iis, itc. G'» 



longitudinal stripe ; a dark stripe from o.yc to mouth and 

 another from eye to interopenmlnm ; dorsal with a Ijlackish 

 (df^cj posterior j)art of soft dorsal and anal and middle of 

 caudal sometimes spotted. 



Upper course of the Paraj^nay. 



1. (.'{8 mm.) Caraudaiiirilio, MnUn (irossu. Dr. A. Burclli. 



2-"). (24-yti nun.) L'olonia Itis^io. J)i. A. lioielli. 



5. Ileterogramma trifasciatinn. 



Me.iop.^ Ueniatus (^p:irt.), Bouleng. Boll. Mus. Torin. x. \SO-i, no. 190, 



p. :W. 

 L'iotodomn tn'fanciafum, Eif^enm. & Kennodv, Proc. Ac. Philad. 190.'J, 



p. 5;i0; Peili'fn-. MtSni. Soc. Zool. France, 'xvi. PJ03, p. 188 (1904). 



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

 Snout shorter than eye, the diameter of which is 2^ in the 

 length of head, intcrorbital width S^. Depth of priEorbital 

 )^ the diameter of eye. Maxillary extending to below ante- 

 rior margin of eye ; jaws equal anteriorly ; fold of the 

 lower lip continuous; check with 8 scries of scales ; no 

 scales on the praioperculum ; no distinct gill-rakers ou the 

 lower part of anterior arch. Scales 24 ^ ; upper lateral line 

 fully developed on 7-0 scales only; lower lateral line rudi- 

 mentary. Dorsal XV-XVI G, the sj)iues subequal from the 

 fourth, the last ^ the length of head. Anal III 5-G. 

 Caudal peduncle scarcely deeper than long. Brownish ; a 

 dark longitudinal stripe from eye to base of caudal, con- 

 tinued anteriorly from eye to mouth ; an oblique dark stripe 

 from eye to interoperculura, another from base of pectoral 

 to origin of anal. 



Upper course of the Paraguay. 



1. (30 mm.) Colonia Risso. Dr. A. Borelli. 



The specimen described above appears to have a some- 

 what smaller head and broader intcrorbital space than one 

 of /f. commbree of the same size. The very different coloration 

 leaves no doubt as to the distinctness of this species. 



BlOTOECUS. 



Sttrarn (non Wr.lk.), Stciiid. Sitzb. .Ak. Wion, Ixxi. 187o, p. 1:.'.'). 

 Biotoectut, Eigennj. iic Ivennedv, PrdC. Ac. Philad. 1H03, p. ."j"].'] ; 

 IVll.-j-'^r. Mem. Sue. Zuol. Franco, xvi. l!iO:3, p. 199 (1904), 



Differs from Geopfu/f/usviud Httcrogramma in the structure 

 of the dorsal fin, which has VII-VIII 13-14 rays. Lateral 

 line usually rudimentary; caudal slightly emarginate. 



A single species from the Amazon. 

 Ann. A: Muj. A', llibt. Ser. 7. Vol. xvii. 5 



