1913.] NATURAL SCIENCES OF PHILADELPHIA. 573 



dorsal and adipose fin. Occipital process bordered by median scute 

 behind and two others on each side. Edge of gill-opening bordered 

 with slightly enlarged spinules. Lower surface of head and abdomen 

 covered with small granular scales, all densely and minutely spinu- 

 lose. Fin spines all spinulose, those on outer and inner edges of 

 pectoral both larger and forming rather regular rows, former en- 

 larged distally. Outer surfaces of fin rays minutely spinulose. 

 L. I. evident as 8 simple small pores extending back from opercle. 



Dorsal origin a little nearer snout tip than adipose fin origin, and 

 depressed spine extends back about half way in length of last de- 

 pressed ray. Adipose fin strong spine, If to caudal base, inserted 

 near last third in space between dorsal origin and caudal base. Anal 

 inserted well behind dorsal base or about midway between dorsal 

 origin and caudal base, weak spine nearly long as subequal rays, and 

 depressed fin extends about half way to caudal base. Caudal 

 moderate, well emarginate behind, and lower lobe slightly longer. 

 Pectoral spine large, depressed, reaches back slightly beyond ventral 

 origin, rays slender. Ventral inserted just behind first dorsal ray 

 base, spine moderate and tapering to flexible point which extends 

 back opposite anal origin. Vent at last | in space between ventral 

 origin and that of anal. 



Color in alcohol brown above, lower surface paler or more whitish , 

 faded creamy. Iris slaty, pupil darker, and light spot below. Head 

 above entirely dotted with deep brown, dots close-set and numerous. 

 Back and costal region above marked with rounded deep brown 

 spots, all larger than on head, several on each of anterior scutes, 

 though only one to a scute on body posteriorly. Dorsal fin with 

 4 to 6 small, rounded, blackish spots on each ray, these well contrasted 

 or very distinct, those on spine less so. Caudal with about 8 rows of 

 dusky spots on rays. Pectoral and ventral spotted obscurely with 

 brownish. Anal whitish. Posterior sides of body from above 

 ventral origin to lower caudal lobe immaculate and whitish. 



Length 105 mm. 



Type, No. 39,312, A. N. S. P. Madeira River, about 200 miles 

 east of W. Long. 63° 54', Brazil. September, 1912. Edgar A. Smith. 



Only the type known. It appears to be most closely related to 

 Plecostomus cordovce Gtinther," differing somewhat in the coloration, 

 as all the spots on the fins are on the fin rays in the present species. 



11 Anw. Mag. Nat. Hist., London, (5) VI, 1880, p. 11. Cordova, Argentina. ' 



Regan, Trans. Zool. Soc, London, XVII, 1904, p. 212, PI. 9, fig. 3. 



Cordova. 



