Eigenmann: On Apareiodon. 73 



5807 a-m, C. M. (Young) 24-43 mm. Same lot as 5806, C. M. 

 Haseman. 



5808 o, C. M. 26 mm. Timbo, Rio Itapicuru, IVIarch 5, 1908. 

 Haseman. 



5809 a, C. M. 48 mm. Rio Aqua Branca, Nov. 6, 1907. Haseman. 

 Closely related to A. piracicahm (Eigenmann), differing in the slightly 



larger scales, longer head, and in coloration. 



Head 4-4.5; depth 4-4.5; D. 11, rarely 12; A. 8, the first ray, a 

 mere rudiment; scales 4-35 or 36-3. Eye 1.25 in snout, 3.5 in head; 

 snout equal to interorbital, which is 3 in the head. Occipital process 

 bluntly rounded, bordered by two or three scales; no fontanels. A 

 regular median predorsal series of ten or eleven scales. 



Dorsal profile gently curved, ventral profile flattened, horizontal or 

 curved. Depth of caudal peduncle about half the depth at dorsal. 

 Snout conical; mouth inferior; four slender multicuspid premaxillary 

 teeth, two minute maxillary teeth, no mandibular teeth. 



Origin of the dorsal equidistant from the tip of the snout and a point 

 four or five scales behind the adipose, its height equal to the head less 

 half the opercle. End of anal on, or slightly in advance of, the vertical 

 from the adipose, its height equal to the snout and eye. Ventrals 

 overlap the anus, their origin equidistant from the tip of the snout 

 and the tips of the middle rays of the caudal. Caudal forked, the 

 lobes rounded, their length somewhat less than the head. 



Upper border of snout margined with brownish; a broad band of 

 the same color extends from the upper angle of the opercles along the 

 lateral line to the tips of the middle rays of the caudal. A narrower 

 band extends above and parallel to this through the center of the 

 third row of scales from above the eye to the base of the caudal. The 

 space between these two bands and the ventral surface is whitish or 

 silvery. Extending from the upper band across the dorsal ridge to 

 the corresponding band of the other side is a series of broad vertical 

 bands forming blotches; the first, midway between occiput and 

 dorsal, another through the center of dorsal, and the last over the 

 adipose. These often show through the clear space between the two 

 lateral bands; others, midway between these, extend only over the 

 dorsal ridge. All fins hyaline or colorless, except for faint markings 

 at the base of both lobes of the caudal. 



Young specimens (5807) have all the markings less distinct; the 

 upper lateral stripe is especially late in making its appearance. 



