CATFISHES OF THE GENUS CORYDORAS — ^WEITZMAN 123 



Dorsal fin 1,7, in all specimens, last fin ray split to its base. Neither 

 first spine nor first soft ray of dorsal fin reaches base of adipose spine 

 when dorsal fin depressed. Dorsal fin spine much slenderer and 

 shorter than pectoral fin spine. Adipose spine 1.5 (66.7%) [1.3 (77.8%)] 

 in orbit. Anal fin ii,5, in all specimens, last ray split to base in SU 

 55939 and SM 5349 and not split to its base in USNM 196170. Pec- 

 toral fin 1,11, in SU 55939 and USNM 196170, 1,10, in SM 5349. 

 Pelvic fin rays i,5, in all specimens. Caudal fin with principal rays 

 7/7 in all specimens. Pectoral fin spine (fig. 6) has 26 [24] spinules 

 along its posterior border. There are 22 spinules in SM 5349. 



Figure 6. — Corydoras semiaqiiilus, new species. Pectoral fin spine of holotype, ventral 



view, left spine. 



Color. — The holotype has the follo\ving color in alcohol (see also 

 fig. 5): Ground color white to pale brown. Head with punctate 

 to vermiculate dark brown or black markings, more punctate over snout 

 and between eyes. Sides of head with black to gray markings. Belly, 

 thorax, and lower one-third of body white. Upper two-thirds of body 

 dark except for narrow streak of pale brown below dorsal fin. This 

 pale area extends posteriorly to caudal fin above dorsal margin of 

 body. Dorsal fin with two rather irregular black bars; caudal fin 

 with thi-ee kregular black vertical bars. Anal fin with two black 

 bars. Pelvic fins colorless except for some scattered melanophores 

 over central portions of rays. Basal two-thirds of pectoral fin rays 

 dark and entire pectoral fin spine dark. Color of paratypes very 

 similar to that of holotype. 



Color in life (from a Kodachrome) as follows: Dark areas seen in 

 figure 5 black with slight suggestion of blue and purple. Greenish 

 iridescence over lateral part of coracoid bone and golden iridescence 

 over opercular bone. Pale areas of body very pale brown, somewhat 

 pinkish in thoracic and abdominal regions while pale strip along dorsal 

 edge of body somewhat darker brown. Iris around pupU golden, 

 shading to black at edge of eye. 



The name "semiaquilus" is from Latin (semi=haK and aquilus = 

 dark colored) referring to the dark color on the upper body scutes. 



Discussiox. — The relationships of Corydoras semiaquilus seem to 

 be clearly the long-snouted Corydoras such as treitlii, acutus, cervinus, 

 fowleri, pastazensis, and septentrionalis. So far as known, it differs 

 from all of these but C. fowleri m the possession of a thick laj^er of 

 imbricated dermal plates on the abdomen and thorax. The species 



