310 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
1% times in distance from tip of snout to tip of occipital process; tip of snout 
to occiput about 2% times in length of anal fin base; adipose fin present; 
dorsal rays usually ii, 9; palatines toothless. 
2a. Preventral area trenchant, with low keel, scales forming a median ridge; 
lateral Jine incomplete, with about 13 pores anteriorly; base of caudal fin 
of males without glandular scales; anal sheath of 2 or 2% rows of scales; 
lower jaw included; origin of dorsal midway between rear of eye and base 
of caudal fin; dorsal origin over fifth to seventh branched rays of anal; 
anal rays v or vi, 40 to 44; pectoral i, 12 ori, 13; pelvic i, 7; scales 39 to 41, 
15 % between origins of dorsal and anal fins; depth 2% to 3%; head 4 to 
4% in standard length; snout 3% to 3%, interorbital 2% to 3, eye 2% to 8, 
mouth 1% to 1%, all in length of head; an obscure caudal spot present. 
Paragoniates alburnus Steindachner 
2b. Preventral area rounded, not keeled; lateral line with 3 to 5 pores; base of 
caudal fin of males with glandular scales; anal rays iv or v, 28; pectoral 
i, 10; pelvic i, 6; scales 44; 18 or 14 in a transverse series; eye 3 to 3% and 
interorbital 244 to 234 in the head; head 1% in caudal fin; a distinet grayish 
band along upper side of back. 
Mimagoniates microlepis (Steindachner) 25 
1b. Mouth short, distance from tip of snout to rear of maxillary 14% in postorbital 
length of head, about equal to interorbital width, and 2 to 2% times in 
distance from tip of snout to occiput; tip of snout to occiput 3 to 5 times in 
length of anal fin base. 
3a. Adipose fin absent; palatines toothless; lateral line incomplete, with 9 to 16 
pores; dorsal rays ii, 7; anal rays 49 to 53 (about v, 48 to v, 52); pectorals 
i, 10 ori, 11; pelvies i, 5; scales 40 to 44; origin of dorsal midway between 
base of caudal peduncle and posterior third of eye; iip of snout to occiput 
3% times in anal base; head 4% to 54%o, depth 3% to 3% in standard length; 
snout 3% to 4%, eye 2% to 3, interorbital 2% to 3% in head; about 5+8 
gill rakers on first arch. 
Phenagoniates macrolepis (Meek and Hildebrand) 
3b. Adipose fin present; lateral line complete; dorsal rays 10 or 11; pectoral i, 
11 or i, 12; scales from dorsal origin to lateral line 7 and from anal origin 
to lateral line 7; depth 4, head 5% to 6, length of base of anal fin 1% all in 
standard length; dorsal origin over about twenty-second to twenty-fourth 
anal ray. 
4a. Anal rays 68, pelvic about i, 6; scales 48; dorsal origin an equal distance 
between pupil and midbase of caudal fin; palatines without teeth. 
Leptagoniates steindachneri 26 Boulenger 2! 
4b. Anal rays 63 to 66; pelvic i, 5 or i, 6; scales 50 or 51; origin of dorsal an 
equal distance between middle third of length of pectoral fin and 
midbase of caudal fin; palatines with a small patch of teeth. 
Xenagoniates bondi Myers 
25 Paragoniates microlepis Steindachner, Sitzb. Akad. Wiss. Wien, vol. 74, p. 33, 1876 (Bache in der Nahe 
von Rio Janeiro, Rio dos Macacos).—Eigenmann, Repts. Princeton Univ. Exped. Patagonia 1896-1899, 
vol. 3, pt. 4, p. 441, 1910. This species was included here because it superficially resembles Paragoniates 
Steindachner but differs from that group by having two rows of teeth on each premaxillary. 
26 A. Fraser-Brunner, British Museum (Natural History), kindly examined the type of this species and 
states in a letter to me dated June 19, 1944: ‘““There are no teeth on the palatines, nor on vomer; there are 
18 teeth in upper jaw, 10 in the lower. The dorsal fin has 3 simple rays followed by 8 branched rays. All 
the 68 anal rays are simple. The uppermost pectoral ray is simple and thickened, the 11 following being 
branched; the pelvic has i, 6, the first being stout and strong. There are 48 scales.’’ 
27 Leptagoniates steindachneri Boulenger, Proc. Zool. Soc. London, 1887, pp. 281, 282, pl. 23, fig. 3 (Sarayacu, 
Ecuador).—Eigenmann, Repts. Princeton Univ. Exped. Patagonia 1896-1899, vol. 3, Zoology, pt. 4, p. 441, 
1910.—Eigenmann and Allen, Fishes of Western South America, p. 270, 1942. 
Myers (1942) gives for this species the following reference, which I have not seen: Arnold and Ahl, Frem- 
lind, Siisswasserf., 1936, p. 89. j 
