Cope.] ^^^ [Jan. 5, 



llie character which I have assigned to Gastrodernius, which is therefore 

 the true Corydoras. It therefore becomes necessary to give the genus 

 with armored thorax a new generic name. This I propose shall be Osleo 

 gaster. The type is the Corydoras egaes of Steindachner, and the only 

 other species which can be positively assigned to it is, according to 

 Eigenmann, the C. splendens Castelnau. 



ICHTHYOCEPHALT. 



Prof. Gill has called my attention to an error which occurs in my 

 paper on the classification of fishes published in 1871, in the exchanged 

 places of the genera Monopterus and Symb:anchus. The characters of 

 the one are by an inadvertence ascribed to the other, bj'^ an accidental 

 exchange of the names. 



Syaibkanchid^. 



SyMBRANCHUS MARldOBATUS Bloch. 



HAPLOMI. 



Cyprinodontid^. 



GiKARDiNUS CAUDiMACULATUS Hensel., Arch.f. Naturgescli., 1870, p. 362 ; 

 Von J bring. Susswasserf. v. Rio Grande do Sul, 1893, p. 28. 



Depth of body a little greater than length of head. Dorsal fin origiua- 

 ting above middle of anal. Scales 28-8. Radii, D. I. 7 ; A. 10. Eye 

 one-third head, exceeding length of muzzle, and 1.5 times in interorbital 

 width. Scales between interorbital space and dorsal fin, 18. Yellowish 

 with a black vertical spot on the thirteenth scale from the caudal fin. 



PERCOMORPHI. 



ClCHLlD^. 



Crenicichla lepidota Meckel ; Steindachner, Sitzber. K, Wien Akad. 

 Wiss., 1874, p. 22. 

 Numerous specimens ; evidently the common perch of the Jacuhy. 



Crenicichi.a lacustris Cast.; Steindachner, Sitzber. K. Wien Akad. 

 Wiss., Dec, 1874, p. 18. 

 Form elongate, body compressed ; profile gently decurved from the 

 first dorsal ray to the upper lip, which is less produced than the promi- 

 nent mandible. The length of the head is contained in the total 8.6(i 

 times, and into that of the head and body three times. Depth of body 

 contained in total 5.5 times, and into that of head and body 4.5 times. 

 Eye not large, entering length of head 6.5 times ; twice in muzzle with- 

 out chin, and 1.6 limes in interorbital space, which is slightly convex 

 transversely. Scales ^; those of the lateral line fewer than those of the 

 transverse rows, for the reason that on the anterior part of the body one 

 lateral line scale is bounded by three scales of the transverse rows, and 



