SILURIDA. 81 
** Caudal fin not forked, rounded or usually somewhat emarginate, nearly truncate 
when spread open: 
}. Body moderately elongate, depth one-fifth or more of length; branchiostegals 
normally 9 or 10: 
c. Anal fin very long, its base one-fourth or more of length of body, of 24 to 26 
rays; dorsal spine normally nearer snout than adipose fin : 
—. Head and body elongated; the dorsal region considerably elevated ; the 
head quite long and narrowed forwards; much longer than 
broad ; its width in front of eye only about half its length; 
mouth rather narrow, with equal jaws; barbels long; adipose 
fin large; spines strong; dorsal fin very high; anal fin long 
and deep ; caudal fin short; color dark ...../--. EREBENNUS, 11. 
— — Head wide and flattish, not much Jonger than broad; rounded in front ; 
the mouth very wide; the dorsal region not much elevated; 
body more or less stout and thick; branchiostegals 8 or 9; 
jaws equal or upper jaw longest .----......-.--... NATALIS, 12. 
w. Dorsal considerably nearer snout than adipose fin: 
x. Jaws equal; spines very short ; anal rays 25; colors yellowish-brown, Lividus, b. 
ava. Upper jaw distinctly longest : 
y. Anal rays 24 or 25, its rays less than half head, its base 3} in length of 
body ; the nape not swollen : 
ZAUVOLOLS Pale nye LLOWwAISh-DLOWwllesaer cae eee cei acme cee ooelecieeeel Cupreus, ¢. 
Zee OloUsdanic nplack. OL OTCOMISM sayy sereneeishaa ee eee oa Canosus, d. 
yy. Anal rays 26; base of anal 3} in length, its rays short, less than half length 
of head; spines weak; head 34 to 32 in length; distance to 
dorsal spine 2% to 2%; the nape more or less swollen and 
GLOW AEC CIMA SAEs Bea els Rene RENE: AA bo Vine Op ap! Se Rk Antoniensis, c. 
yyy. Anal rays 27, its base elongate, 34 in length, its longest rays more than 
half head; spines strong; head short, 4 in length, the distance 
to dorsal nearly 3; nape not swollen. -....-.-.......-- Analis, 
ww. Dorsal rather nearer adipose fin than snout; the posterior part of the body 
being much thicker and proportionally shortened; the caudal 
fin short; dorsal and ventral outlines nearly parallel; jaws 
aboutrequallt ste. steers se ena oek atee sels mess: Natalis, a. 
cc. Anal fin moderate, of 19 to 22 rays; branchiostegals normally & or 9: 
d. Lower jaw distinctly longest; anal rays 20: 
e. Body moderately elongate, depth 43 to 5 in length; head 33 to 4; barbel 
long; mouth wide; head longer than broad, rather narrowed 
forward; profile rather steep, pretty evenly convex; dorsal re- 
gion more or less elevated ; dorsal spine nearer snout than adi- 
pose fin ; lower jaw strongly projecting ; color blackish (varying 
in subspecies wlurus to head blunter and flatter above; dorsal 
spine rather nearer adipose fin) ...........----.- VULGARIS, 13. 
dd. Jaws equal, or upper jaw projecting beyond lower: 
f. Eyes distinct, well developed : 
g. Head moderately broad, a nearly even slope from the tip of the snout to 
the elevated base of the dorsal : 
—. Body sharply mottled with brown, greenish, and whitish; the colora- 
tion therefore singular among Cattfishes ; jaws equal or nearly so; 
depth about 4 in length; slope of profile very steep; dorsal fin 
high; the spine more than half length of head; dorsal spine 
nearer adipose fin than snout; barbels long; branchiostegals 
LOEWhead st in emote ciaccternccin scenes es > MARMORATUS, 14. 
Buu. N. M. No. 10—6 
