498 Mr. C. T. Regan — A Revision 



4. Rivuhis urophthahiiHS. 



iiivulue urophthahnus, Giinth. Cat. Fish. vi. p. 327 (1866). 

 Rivulus poeyi, Steind. Sitzungsb. Akad. Wien, Ixxiv. 1877, p. 165. 

 Jiivulus brasiliensis {non Val.), Garman, Mem. Mus. Comp. Zool. xix. 

 • 1895, p. 135. 

 Rivulus stagnaius, Eigeiim. Anu. Carnegie Mus. vi. 1909, pp. 49, 50; 



Mem. Carnegie Mus. v. 1912, pp. 453, ^54, pi. Ixiii. figs. 0, 7. 

 Rivtdus laiiceokitus, Eigenm. t. c. pp. 49, 51 & t. c. pp. 453, 455, 



pi. Ixiv. fig. 1. 

 Rivulus frenatus, Eigenm. I. c. & t. c. pp. 453, 455, pi. Ixiv. fig. 2. 



Depth of body 4^ to 5^ iu the length, length of head 4 

 to 44. Head broader than deep. Diameter of eye 3 to 3f 

 in the length of head. 37 to 42 scales in a longitudinal 

 seriesi Dorsal 6-7 ; origin above last rays of anal, more 

 than twice as distant from head, and 2| to 3^ as distant 

 from feye as from base of caudal fin. Anal 11-13^ ending 

 below anterior part or middle of dorsal. Pectoral ^ the 

 length of head3 not extending to pelvics, which just reach 

 the vent. Olivaceous ; each scale sometimes with a dark 

 spot ; sometimes longitudinal stripes between series of scales 

 on sides ; dorsal, caudal, and sometimes anal with series of 

 small dark spots; caudal ocellus sometimes present ( ? ). 

 Amazon ; Guiana. 



1-5 (types). 35-60 mm. Para. 



6-8. 35-45 mm. ,, Eigenm ann, 



7-9 (co-types of i2.eif/^?in<Ms). 35-38 mm. Cbristianburg. „ 



This description was written from the Para specimens and 

 was fonnd to need no modification to include the co-types of 

 R. stagnaius. R. lanceolatus is evidently the same species, 

 the apparently different form of the caudal fin being due to 

 the fact that it is less expanded. R. frenatus is said to have 

 oidy 23 scales in front of the dorsal and the anal origin 

 equidistant from base of caudal and prceoperculum, but from 

 the figure it would seem that there are about 29 scales from 

 head to origin of dorsal fin and that the anal origin is equi- 

 distant from base of pectoral and base of caudal, as in small 

 specimens of R. urophthahnus from Para, or in the co-types 

 of R. stagnatus. 



5. Rivulus elegans. 



Rivulus eleyans, Steiud. Denkschr. Akad. Wien, xlii. 1880, p. 85, 

 pi. vi. fig. 6. 



Depth of body about 6 in the length, length of head 

 about 4. Head broader than deep. Diameter of eye 3 to 

 3^ in the length of head. 36 to 40 scales in a longitudinal 

 series. Dorsal 6-8 ; origin above posterior ^ of anal, about 



f 



