426 DR. A. GUNTHER ON NEW FISHES FROM PERU. [June 10, 
than one-third of the total (without caudal). Head withont any 
ridges above; interorbital space exceedingly broad, its width being 
five times the horizontal diameter of the small eye. Snout covered 
with small scutes, which are rough with small spines along the mar- 
gin. Interoperculum with two kinds of spines, there being a 
group of about twelve slender but stiff and slightly hooked spines 
surrounded by a ring of long setiform spines; the longest of the stiff 
spines is about twice the length of the orbit, and the longest setiform 
spine about thrice that length. Thorax and abdomen nearly naked, 
with non-confluent minute granulations. Teeth exceedingly fine. 
Dorsal fin higher than long, but the spine is much shorter than the 
head. There are seven scutes between the two dorsal fins. The 
pectoral spine extends beyond the middle of the ventral, the ventral 
beyond the anal. Eleven scutes between the anal and caudal. 
Scutes without keels, rough, but without prominent spines. Uniform 
greyish ; each dorsal scute lighter in the centre. ; 
One specimen, 73 inches long. 
CH2XTOSTOMUS LATIFRONS. 
D. 1/8. A. 5. L. lat. 25. 
Head much depressed, a little longer than broad, its length being 
rather more than one-third of the total (without caudal). Head 
without any ridges above; interorbital space broad, the diameter of 
the eye being somewhat less than one-third of its width. Snout 
naked, without tentacles. Interoperculum with about sixteen spines, 
hooked at the apex, the longest being nearly twice the length of the 
eye. Thorax and abdomen naked. Scutes without ridge, but spiny, 
the marginal spines being rather strong and prominent. Teeth 
exceedingly fine. Dorsal fin rather higher than long, the first ray 
rather feeble, shorter than the head. ‘There are six scutes between 
the two dorsal fins. The pectoral spine does not extend to the middie 
of the ventral ; the ventral reaches beyond the anal. Eleven scutes 
between the anal and caudal. Pectoral spine rough, Uuiform black. 
One specimen, 7 inches long. 
LoricariA MACRoMysTAx. (Figs. 5 & 6, pp. 427, 428.) 
Snout somewhat produced and rather narrow, slightly concave on 
the side ; mouth of moderate width, the upper lip terminating late- 
rally in a long barbel, extending beyond the axil of the pectoral fin ; 
lower lip broad, with numerous barbels and smaller fringes. Small 
teeth in both jaws. Orbit with a very shallow notch behind, its hori- 
zontal diameter being not quite equal to the width of the interorbital 
space. Scutes smooth, the lateral ridges distinct and confluent on 
the eighteenth scute. Lz. lat. 31. A series of eight or nine scutes 
between the roots of the ventral and pectoral fins. Thorax and 
abdomen covered with numerous, small, irregular scutella. Of the 
fin-rays only the upper of the caudal is produced. Origin of the 
dorsal opposite to the root of the ventral. Coloration uniform. 
‘One specimen, 7 inches long. 
