NATURAL SCIENCES OF PHILADELPHIA. 253 



1.33 times to 1.6 times in interorbital breadth. Scales 4 — 56-3' 12 



13, seven rows on cheek. Color olivaceous, blackish above; fins 

 dusln-, without markings, except a black ocellus at upper base of 

 caudal fin, with pale margin. A dusky band from end of muzzle 

 to middle of side, and dusky spot below eye. Eye red. Total 

 length .17 m. 



Var. a. — Shorter and stouter, colors paler. 'Eye 1.5 times in 

 interorbital width. Depth of body 3f to 4 times in length less 

 caudal. Scales 4 — 45-8 — 13. Pattern of color similar to the last. 

 Several specimens. 



Var. i3. — More slender; depth 4.66 times in length without 

 caudal fin. Radii xviii-14 ; A. iii-9. Scales 4-55-13. Diameter 

 of orbit equal interorbital space. Coloration as in the t3'pes, ex- 

 cept a large black spot marking the posterior fourth of the spinous 

 dorsal fin. This variety has one less dorsal spine than usual in 

 the tj^pe, but the latter occasionally exhibits but 18. 



Var. y (argijnnis). — Short and stout as in var. a, but the 

 orbit is as wide as the narrowed interorbital space; scales 4-43- 

 13. Radii D. xix. 13; A. iii. 9. The coloration is like that of the 

 type, olive, darker above, with caudal ocellus and dusky band 

 from muzzle to opercular margin. The dorsal fin has, however, a 

 ^broad orange-red band extending along its distal posterior half, 

 the anterior part wider and with three large black spots in the 

 centre ; in a second specimen it contains four black spots. 



The preceding varieties are so connected together as to be in- 

 separable in our S3^stem. The var. /3 accords to some extent with 

 Castelnau's description of his C. lacustris, but our most slender 

 forms are less elongate than this species, where the depth is one- 

 sixth the length. There are neither black dots nor vittfe in the 

 C. proteus. From C. saxatilis, to which it is next allied, it dif- 

 fers in the constantly smaller number of longitudinal scales, which 

 are given by Giinther as j^. 



TJARUS INSIGNIS, Heckel. 



Mesonauta insignis, Giinther, 1. c. iv. 300. 



ITAEUS CENTKARCHOIDES, Cope, sp. nov. 



Form a compressed broad oval. Scales ctenoid T— 29-20 — 14, 

 five series on the cheek ; operculum scaled. Radii D. xv-1 4 ; anal 



* Not counted on lateral line. 

 1872.] 



