142 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 99 



la. Anal rays 111,8. 



2a. Gill rakers on lower part of gill arch 10 or 11; dusky bars on sides of young 

 but adults with dusky punctulations and no bars; second dorsal spine a 

 little shorter than third, both shorter than head, the second contained 

 nearly 4 times in standard length; second anal spine strong, but a little 

 shorter than third, the second anal spine 1.8 in head and 1.5 in second 

 dorsal spine; area over premaxillary groove free of scales in young but 

 covered with small scales in large specimens. 



Diapterus olisthostomus (Goode and Bean) 

 26. Gill rakers on lower part of first arch 15; second dorsal spine a little shorter 

 than third, the second spine about 1}^ in head; second anal spine enlarged, 

 a little longer than third spine, the second 1.5 in head and lYs in second 

 dorsal spine; second row of scales below lateral line continuous to end of 

 caudal; area over premaxilary processes on top of head free from scales; 

 no dark stripes or distinct bars visible. 



Diapterus limnaeus, new species 

 16. Anal rays II,i,8 or 11,9. 



3a. Anal rays 11,9; gill rakers on lower part of first arch 14 or 15, rarely 16; 

 second dorsal spine a little shorter than third, the second spine contained 

 1.2 to 1.4 in head and about 3.2 to 3.5 in standard length; second anal 

 spine 1.4 to 1.6 in head and 4 to 4.5 in standard length; second row of 

 scales below lateral line continuous to caudal fin. 



Diapterus rhombeus (Cuvier) 

 36. Anal rays II,i,8: gill rakers 10 or 11 on lower part of first arch; second dorsal 

 spine a little shorter than third, about 1}^ to IJ^ in head and 3.5 to 3.75 

 in standard length; second anal spine strong, 1.6 in head and 4.2 in 

 standard length; third row of scales below lateral line continuous to 

 caudal Diapterus evermanni Meek and Hildebrand 



DIAPTERUS OLISTHOSTOMUS (Goode and Bean) 



Gerres olisthostoma Goode and Bean, Proc. U. S. Nat. Mus., vol. 5, p. 423, 1882 

 (Indian River, Fla.). 



U.S.N, M. No. 121941, 1 specimen, 177 mm. in standard length, Amuay Bay, 

 Gulf of Venezuela, U. S. S. Niagara, May 15, 1925. 



DIAPTERUS UMNAEUS, new species 



FiGUBE 16 



Holotype. — U.S.N.M. No. 121726, only known specimen, 08 mm. 

 in standard length, collected by Leonard P. Schultz in Lago de 

 Maracaibo at Maracaibo Yacht Club, May 16, 1942. 



Description. — Certain measurements were made on the holotype 

 and these are recorded in hundredths of the standard length in 

 table 18. 



The following counts were made: Dorsal rays IX, 10; anal rays 

 111,8; pectoral rays iii,12-iii, 12; scales from upper edge of gill opening 

 to midcaudal fin base 40; scales from base of first soft ray of dorsal 

 to lateral line 4, and 9 from base of first anal spine to lateral line; 

 gill rakers on lower part of first arch 15. 



Greatest depth of body 2.2 and head 3, in standard length; snout 

 3.25, eye about 2%, and postorbital length of head 2}^ in length of 



