CATFISHES OF THE GENUS CORYDORAS — WEITZMAN 



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Description. — (For actual measurements see table 1.) In the 

 description below, the proportions are given first, percentages follow 

 in parentheses, both of which derive from standard length unless 

 otherwise designated. Data for the lectotype, NMW 61103, is 

 given fii-st, data for NMW 4779S follows in brackets. Data for USNM 

 179612 and for SU 35054 are designated by respective abbreviations. 



Figure 1. — Corydoras ireillii Steindachner, lectotype, NMW 61103. Standard length 



42.6 mm. 



Body fairly elongate, compressed posteriorly. Greatest body depth 

 2.9 (34.8%) [2.8 (35.6%)], USNM 2.8 (35.8%), SU 2.9 (34.4%). 

 Least depth of caudal peduncle 7.5 (13.4%) [7.2 (13.9%)], USNM 7.7 

 (15.0%), SU 7.6 (13.1%). Distance between snout tip and dorsal fin 

 origin 1.8 (56.4%) [2.0 (49.1%)], USNM 2.0 (51.0%), SU 1.9 (52.3%). 

 Distance between snout tip and anus 1.9 (52.8%) [1.8 (55.0%)], 

 USNM 1.9 (52.0%), SU 2.0 (49.8%). Anal fin origin to snout tip 

 1.3 (80.0%) [1.2 (80.8%)], USNM 1.3 (79.8%), SU 1.2 (80.6%). 

 Lateral scutes 24/21 in all four specimens. Abdomen and thorax 

 with small prickles in all specimens, no heavy imbricated plates. 

 In SU 35054, a poorlj'- preserved specimen, many of these pricldes have 

 been broken off in exposed areas but their bases remain. Azygous 

 middorsal scutes 6 [4], USNM 4, SU 5, before adipose fin. One 

 ar.ygous scute before dorsal fin in all specimens. Pectoral fin base 

 incompletely surrounded by coracoid in all specimens. Distance 

 between coracoids variable (probably ■wider in females than in males) 

 10.9 (9.2%) [9.2 (10.9%)], USNM 11.3 (8.8%), SU 13.4 (7.5%). 

 Head length 3.0 (33.3%) [2.9 (33.8%)], USNM 3.0 (33.3%), SU 

 (34.2%). Greatest head width 1.4 (71.8%) [1.5 (68.7%)], USNM 1.5 

 (67.4%), SU 1.7 (59.5%) in head length. Least width of bony inter- 



