128 THE AMERICAN CHARACIDAE. 
7. TuHayertia Eigenmann. 
In memory of Nathaniel Thayer. 
Thayeria EIGENMANN, Bull. M. C. Z., 1908, 62, p. 94. 
Typr.— Thayeria obliqua Eigenmann. 
Small, elongate Tetragonopterids reaching a length of near 80 mm., dis- 
tinguished from all others by the unequally lobed caudal. It is otherwise 
near Hemigrammus and Creatochanes. Caudal scaled, lateral line incomplete. 
Hasirat.— Amazon Basin. 
THAYERIA OBLIQUA Eigenmann. 
AX el VND 
Plate 3, fig. 5, Plate 80, fig. 1, 2, 4, 6. 
Thayeria obliquus EIGENMANN, Bull. M. C. Z., 1908, 52, p. 94 (Obidos); Rept. Princeton univ. exped. 
Patagonia, 1910, 3, p. 437. 
Specimens examined. 
Number of 
Catalogue number specimens Size in mm. Locality Collector 
20841 Cotype 25 47-76 Obidos Bentos 
3712 C. 5 47-62 Bastos Haseman 
TE } 4 52-62 Maciél, Rio Guaporé Haseman 
3711 C. ? 
Head about equal to the depth, 2.6 (in young)-3 in the length; D.10.5— 
11; A. usually 16 or 17, rarely 15 or 181; scales 5-11 + 18-3; eye in the 
smallest equals twice the length of the snout, 2.4 in head, slightly greater than 
the interorbital; in the adult 2.9 in head, equal to the interorbital. 
Little compressed, elongate, but little deeper than the head at the occi- 
put; profile gently and evenly convex to the tip of the occipital process. 
Preventral and postventral areas rounded. Predorsal area rounded, with 
a median series of scales. 
Occipital process short, its length about six in the distance from its base 
to the dorsal, bordered by three scales; nares close together, separated by a 
flap only; frontal fontanel about half as long as the parietal, triangular, the 
anterior angle sometimes rounded, above the anterior margin of the pupil; 
‘In a count I found one with fifteen anal rays, five with sixteen, six with seventeen, and two with 
eighteen. 
