Ki lis : The Pla i i i> Nem vtogn \i as. :>X7 



[574 C. M., 110S7 I U. M. Kumaka, Demerara, British Gu 

 1908. Coll. Eigenmann. 



3. Callichthys arcifer Hensel. 

 Callichthys arcifer Hensel, Wiegm. Archiv.. 1868, I, 373 (Rio de Janeiro). 

 Xo specimens. 



Cascadura, 3 gen. nov. 



Breast as in Callichthys, mouth subterminal as in Callichthys. the 

 occipital process not meeting the dorsal plate, the nuchal plates not 

 meeting along the middle line between the dorsal and occipital process. 

 Fontanels very large, the bridge between them over the eye. Anterior 

 fontanel about as large as the eye, the posterior a little longer than 

 the eye, cutting into the occipital bone. In general appearance this 

 genus resembles Hoplosternum, from which it differs in its concealed 

 coracoid processes. 



4. Cascadura maculocephala, sp. nov. (Plate XXV, fig. 3.) 



3539 C. M. Type, 66 mm. Uruguayana, Feb. 7, 1909. Coll. 

 Haseman. 

 Head to end of opercle 3.3; depth 3.2; width 4; D. I, 7; A. I, 6, 



2S . 



P. I + 8; lateral plates - ; eye 7 in the head, 3.8 in the interorbital 



23 

 space. 



Deepest and widest at the base of the first dorsal rays. Snout 

 depressed, body compressed. Dorsal profile quite steep to the 

 dorsal, gently sloping downwards and backwards to the caudal. 

 Ventral profile nearly straight to the anal, sloping abruptly back 

 and upwards to the caudal; nuchal and lateral plates leaving a 

 naked area above and below, 1.5 the width of the eye. Breast, belly 

 and head covered with skin, only the upper half of the opercle 

 naked. 



Width of head 1.2 in its length, depressed in front; eyes lateral. 

 Fontanel twice the length of the eye, a bridge at the middle over the 

 eye, posterior fontanel cutting into the occipital. Isthmus jugular. 

 2.6 in the head. Snout blunt and square, its length 2.1 in the head. 

 Upper lip vertical, overhanging the weak lower jaw. Teeth very 



* Popular designation in parts of South America. 



