314 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
U.S.N.M. No. 121509, 13 examples, 20 to 23 mm., Rio San Pedro at bridge 
south of Mene Grande, Motatan System, March 20. 
U.S.N.M. No. 121514, a specimen, 18.5 mm., from mouth of Cafio de Sagua, 
35 km. north of Sinamaica, March 12. 
U.S.N.M. No. 121516, 3 specimens, 16.5 to 21 mm., Rio San Ignacio in drying-up 
pool, about 20 km. south of Rosario, February 26. 
U.S.N.M. No. 121510, 4 examples, 19 to 22 mm., Rio Apén about 35 km. south 
of Rosario, February 26. 
U.S.N.M. No. 121512, a specimen, 24 mm., from cafio 34 km. west of Sina- 
maica, March 11. 
U.S.N.M. No. 121515, a specimen, 25.5 mm., Rfo Jimelles, 12 km. east of 
Motatdn, Motatén system, March 24. 
U.S.N.M. No. 121517, a specimen, 20 mm., Rio San Juan, 12 km. south of 
Rosario, February 26. 
The maxillary has 2 or 3 teeth and on each premaxillary 5 teeth; 
dentary with 6 or 7 teeth on each side; all teeth are with 6 or 7 points. 
There are about 6 pores in the lateral line and the scales vary from 
27 to 31; about 10 scales in front of the dorsal origin; gill rakers about 
6 or 7+10 or 11. Additional counts are recorded in table 18. ° 
Tn life, the base of each lobe of caudal fin has a bright orange spot; 
dorsal and anal fins orange. 
TABLE 18.—Counts made on Cheirodon insignis from the Maracaibo Basin 
Number of fin rays 
iN Interhaemals on lower side of 
caudal peduncle on adult males 
Dorsal Anal Pelvic Pectoral 
CEM T TOTTI CA RGaTE MUTUAL URC ERIN RATATAT HV ETCH se 
ii, 9 | ii, 10 iii, 14liii, 15 ii, 16/444, 17 iii, 18 iii, 19 Te I My eat SK) I Sy, TL aA GS Ah aig) 70) 1) bak ob om) 
ii, 8 
SACCODERMA, new genus 
Genotype.—Saccoderma melanostigma, new species. 
Named Saccoderma in reference to the dermal sac on the caudal fin. 
This new genus, Saccoderma, is proposed to include those species of 
fish now referred to the genus QOdontostilbe Cope that have on the 
lower lobe of the caudal fin a dermal bag with the opening posteriorly 
and partially covered by enlarged scales basally and dorsally (fig. 41c), 
as contrasted with the other species which lack this saclike fold of skin 
and are usually described as ‘‘caudal naked in the male.” This latter 
group remain in the genus Odontostilbe. Other characters of this new 
genus are those of the genotype—Saccoderma melanostigma, new 
species, described below. | 
I refer to this new genus one other species, Saccoderma hastata 
(EKigenmann) (= Odontostilbe hastata Kigenmanno), from the Magdelena 
and Atrato Basins of Colombia, represented by two specimens, | 
U.S.N.M. No. 79228. 
