1907.] 



NEAV LORICARIID FISHES. 



797 



to anterior ^ of ventral fin. Caudal emarginate, the middle rays 

 less than ^ as long as the longest. Caudal peduncle 2| as long- 

 as deep. Posterior pai-t of head with undulating stripes ; dorsal fin 

 with the posterior part of each interradial membrane dusky. 



Ilab. Rio Piracicaba, San Paulo, Brazil. 



Two specimens, 150 and 200 mm. in total leng-th, received from 

 Dr. R. von Ihering. 



Plecostomus albopunctatus, sp. n. (Plate XLIX. fig. 1.) 

 Depth of body 5| to 6 in the length, length of head 3 to 3^. 

 Depth of head 2 in its length, breadth of head Ij^, length of 

 snout 1|- to Ij, diameter of eye 9 to 10, interorbital width 3 to 

 3-i-. Length of mandibular ramus Ig to 1| in the interorbital 

 width ; 26 to 32 teeth on each side in the upper jaw, 22 to 26 in 

 the lower. Barbel very short. Snout broad, rounded ; supra- 

 orbital edges not or scarcely raised ; temporal plates not keeled ; 

 supraoccipital slightly convex, without median ridge, bordered 

 posteriorly by a single scute ; occipital process short. Scutes 

 spinulose, not carinate, 26 in a longitudinal series, 6 or 7 between 



Text-fifi-. 206. 



TJecostomns albopunctatus. 

 Head seen from above {a) and below (b). 



dorsal and adipose fin, 12 between anal and caudal. Lower 

 surface of head and abdomen almost completely covered with small 

 granular scales. Dorsal I 7, the first ray i to more than | the 

 length of head, when laid back extending just beyond the base 

 of the last ray, which is f as long as the first. Length of 

 base of dorsal equal to its distance from the posterior part of 

 spine of adipose fin. Anal I 4. Pectoral spine extending to 

 base of ventral fin. Caudal slightly emarginate, the median rays 

 I as long as the longest. Caudal peduncle 2| as long as deep. 

 Small rounded whitish spots on head and body and on the rays of 



54* 



