70 PROCEEDINGS OF THE NATIONAL MUSEUM vol.99 



U.S.N.M. No. 121587, 13 specimens, 156 to 385 mm. in total length, collected 

 with the holotype and bearing same data. 



U.S.N.M. No. 121589, 11 specimens, 164 to 390 mm., Rfo Motatdn at bridge, 

 22 km. north of Motatdn, March 17. 



U.S.N.M. No. 121588, 3 specimens, 215 to 375 mm., Rio Palmar at bridge, 

 70 km. southwest of Maracaibo, March 6. 



U.S.N.M. No. 121590, 7 specimens, 132 to 194 mm., Rio Ap6n about 35 km. 

 south of Rosario, February 26. 



Description. — The following description was based on the holotype 

 and para types. Detailed measurements were made on the former 

 and two of the latter, and these data are expressed in hundredths of 

 the length to end of anal fin and recorded respectively for the holotype 

 and the paratypes in parentheses. 



Total lengths 363 (221; 131.5); length to base of caudal fin 350 

 (213; 128.5) ; length from tip of snout to end of anal fin 330 (202; 121). 

 Greatest depth of body 15.8 (15.8; 16.8); length of head 16.4 (17.1; 

 18.4); length of snout 5.60 (5.79; 6.28); least width of interorbital 

 space 1.82 (2.38; 2.89); diameter of eye 0.76 (0.89; 1.16); distance 

 between anterior and posterior nasal openings 1.67 (1.68; 1.98); 

 distance from eye to posterior nasal opening 2.58 (2.23; 2.07); post- 

 orbital length of head 11.8 (11.7; 11.6); length from tip of snout to 

 rictus 3.82 (3.57; 5.12); width of gill opening 2.49 (2.72; 2.89); least 

 depth of caudal peduncle 1.36 (1.24; 1,65); length of caudal peduncle 

 from end of anal fin to midcaudal base 6.58 (5.60; 5.95); snout to 

 occiput 13.8 (13.6; 15.7); snout to anus 8.33 (8.62; 11.7); snout to 

 pectoral insertion 16.7 (16.7; 18.8); snout to anal origin 15.3 (14.8; 

 11.7); snout to anterior end of groove between dorsal filament and 

 back or rear base of dorsal filament 66.7 (69.0; 65.7) ; length of longest 

 pectoral fin ray 7.88 (8.90; 8.85); longest anal ray 5.91 (6.68; 7.19); 

 longest caudal fin ray 3.24 (3.46; 3.47). 



The following counts were made, respectively: Anal rays 187 

 (197; 181); pectoral rays ii,16-ii,16 (ii,15-ii,16; ii,16-ii,16); number 

 of pores to end of lateral line 100 (101; 96); 3 scales between base of 

 dorsal filament and lateral line. 



Body compressed, caudal region compressed; caudal fin about 

 three-fourths length of snout; caudal peduncle about one-half length 

 of head; pectoral fin length a little over one-half length of head; 

 snout elongate, somewhat pointed, the dorsal profile of head a little 

 concave or straight; greatest depth of body a little behind tips of 

 pectorals; lower edge of gill opening opposite middle of pectoral base 

 or a little below the middle; eye small without a free membrane and 

 contained from 6 to 11 times in the snout; rictus under posterior 

 nostril; anterior nostril tubular; posterior nostril a little closer to 

 eye than tip of snout; anus under a vertical about 2 diameters behind 

 rear of eye; rear edge of base of dorsal filament about equal distance 

 between tip of caudal fin and rear of head or base of pectoral fin; 



