266 Annals of the Carnegie Museum. 



5697 a-d. C. M. Four, 19-25 mm. Santarem, Dec. 15, 1909. 



Haseman. 



Head 3.2; depth 1.5; D. 18-21; A. 32 to 37; abdominal serrae 39 or 

 40 plus, three on either side of the anus; eye 2.5 in the head, about 

 equal to interorbital, .5 in snout. Scales minute; greatest width of 

 opercle about 2.5 in its height. 



The specimens are evidently young and the proportions, especially 

 those about the head, will probably be very different in adults. 



Compressed, subrhomboidal, the profile in front of the dorsal nearly 

 straight, the profile of the serrated portion of the belly rounded; 

 teeth of the outer and inner series of the premaxillary close together. 

 Origin of the dorsal equidistant from tip of snout and base of caudal, 

 highest dorsal ray about equal to snout and eye; adipose short; 

 depth of caudal peduncle about equal to eye; caudal slender, moder- 

 ately forked; anal large, rounded, its origin equidistant from snout 

 with the last dorsal ray; highest anal ray about equal to length of 

 head; ventrals small, under last half of dorsal, reaching anal; pec- 

 torals still archaic. 



Scales minute, largest about the pectorals. Anal naked. 



Like ocellatum, dorsal dark at base, hyaline above the basal fourth; 

 adipose margined with black; caudal hyaline; anal uniformly very 

 dark. Visceral area of sides and lower part of head silvery; sides with 

 alternating light and dark shades which become more evident forward 

 and disappear on the caudal peduncle. In the largest the dark band 

 down from in front of the dorsal is well marked to the visceral area; 

 it is darkest above, just in front of the dorsal; the light band in front 

 of this is well marked; in front of this a dark band is wedge-shaped, 

 its posterior margin more or less parallel with the margin of the band 

 behind it, its anterior margin is very oblique and extends to the middle 

 of the eye, it is darker along the anterior margin and at its upper 

 end; in front of this is another light band which curves forward above 

 the edge to the nares, the median line of the head is also colorless; a 

 line forward from the eye and the area between the median light 

 space just above the eye is again very dark. Chin and ventral edge 

 between the spines with some dark. 



33. Mylosoma albiscopus (Cope). 

 5638 a. C. M. One, 205 mm. San Luiz de Caceres, May 22, 1904. 

 Haseman. 



