294 MR. 0. TATE REGAN ON THE 
diameter of eye 9 times, interorbital width 55 times, length of snout 12 times. Snout 
obtuse. Teeth rather weak, 2 on each side in the upper jaw, 5-6 in the lower. 
30-32 scutes in a lateral series, 14-15+15-18. Abdomen naked except for the lateral 
series of plates and a median strip of plates of moderate size. First dorsal ray as long 
as the head; pectoral spine extending to base of ventral. Breadth of body at level of 
first anal ray about 44 times in the distance from the latter to the caudal. Head and 
body with numerous small dark obloug spots; dorsal, pectoral, and caudal fins with 
similar dark spots. In other characters similar to 1. cataphracta. 
‘The typical example described by Steindachner is 210 mm. in total length. 
R. Mamoni, near Chepo, Panama. 
. 
37. LORICARIA MACROMYSTAX. 
Loricaria macromystax Giiuth. Proc. Zool. Soc. 1869, p. 426, figs. 5 & 6. 
Head 1? times as long as broad, its length nearly 4 times in the total length. 
Diameter of eye 7} times in the length of head, interorbital width 6 times, length of 
snout 1% times. Orbit with a shallow notch; supraoccipital with a pair of very 
indistinct keels; snout laminar, considerably produced, with broad rounded apex; 
upper jaw with 5 or 6 small teeth on each side, lower jaw with 8 or 9; lower lip with 
long fringes; barbel extending nearly to middle of pectoral. 31 scutes in a longitudinal 
series, 17+ 14, the lateral keels very weak and completely united posteriorly. Lower 
surface of head naked except for the marginal plates; space in front of the gill-opening 
not covered with plates ; abdomen covered with small irregnlar plates which are more 
numerous anteriorly ; a lateral series of 10 plates between pectoral and ventral. First 
dorsal ray equal to 3 the length of head; pectoral spine not reaching base of ventral ; 
upper caudal ray probably elongate. Breadth of body at level of first anal ray 
3% times in the distance from that point to the caudal. Olivaceous, without distinct 
markings. 
‘Total length 155 mm. 
One specimen from the Peruvian Amazon. 
38. LORICARIA LAMINA. 
Loricaria lamina Giinth. Proc. Zool. Soc. 1868, p. 239, figs. 6 & 7. 
Head a little longer than broad, its length 44 times in the total length. Diameter 
of eye about 10 times in the length of head, interorbital width 53-5} times, length of 
snout 14 times. Orbit with a shallow notch ; supraoccipital with a pair of almost 
obsolete keels; snout laminar, with a broad rounded apex; upper jaw with 5 or 6 
small teeth on each side, lower jaw with 7 or 8; lower lip with long fringes ; barbel 
extending to the outer angle of the gill-opening. 32-33 scutes in a longitudinal 
series, 15 4-17-18, those in front of the dorsal with very indistinct or obsolete keels 
