IV. SOME SPECIES OF FARLOVVELLA.i 



By C. H. ElGENMANN AND LOLA VaNCE. 

 (Plates XXIX-XXXI.) 



Farlowella Eigenmann & Eigenmann. 



Acestra (non Dallas, 1852) Kner, Denksch. Akad. Wiss. Wien. 1853, p. 93. 

 Farlowella Eigenmann & Eigenmann, Proc. Cal. Acad. Sci. (2), 1889, p. 32 (acus). 



Type, Acestra ecus Kner. Body slender, snout produced into a 

 long rostrum; no orbital notch; teeth numerous, setiform. Dorsal I, 

 6, opposite to anal. Anal I, 5; pectorals I, 5-6; ventrals I, 4-5. 

 Vertebrae 5 + 7+23 (in F. kneri); ribs absent. 



Range. — Paraguay, Amazon, Essequibo, Orinoco, and Magdalena 

 river-systems. 



The genus Farlowella was reviewed in Eigenmann & Eigenmann, 

 "Occasional Papers of the California Academy of Sciences," Vol. I, 

 1890, pp. 355-358, and by Regan, "Transactions of the Zoological 

 Society," London, Vol. XVII, part III, 1904, pp. 302-305. The 

 most notable contribution since the last mentioned monograph is in 

 Steindachner's paper describing the new species natter eri, boliviana, 

 and pseudogladiolus in the Annalen des K. K. Naturhistorischen Hof- 

 museums, Wien, 1910, pp. 403-406. 



The known species of the genus Farloivella may be distinguished by 



the following key: 



a. Abdomen with a median series of plates between the lateral series. 



b. Length of produced part of snout (measured on the ventral surface from 



the edge of the naked area containing the mouth) two and one-quarter 



to three and one-quarter times in the distance from its tip to the anus. 



c. Distance from the supra-occipital to base of first dorsal ray six to six 



and four-tenths times in the total length. 



d. Diameter of eye eighteen times in the length of the head; length of 



postorbital part of head two and three-quarter times in that 



of the produced part of snout i. gladius (Boulenger). 



dd. Diameter of eye twelve and one-half times in the length of head ; 

 length of postorbital part of head three and three-quarter times 

 in that of the produced part of snout 2. gracilis Regan. 



1 Contributions from the Zoological Laboratory of Indiana University, No. 136. 



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