796 MK. C. TATE REGAN OX [Nov. 12, 



Hah. Rio Piracicaba, San Paulo, Brazil. 



A single specimen, 150 mm. in total length, received from 

 Dr. R. von Ihering. 



Plecostomus margaritifer, sp. n. (Plate XLVII. fig. 2.) 



Depth of body 4| in the length, length of head 3i. Depth of 

 head If in its length, breadth of head 1|, length of snout If, 

 diameter of eye 6, interorbital width 2f . Length of mandibular 

 ramus li in the interorbital width; 18 to 20 teeth on each side 

 in the upper jaw, 15 to 17 in the lower. Barbel | the diameter 

 of eye. iSnout obtuse, narrowed anteriorly; supraorbital edges 

 slightly raised ; temporal plates not keeled ; supraoccipital slightly 

 convex, bordered posteriorly by a single scute ; occipital process 

 short. Scutes spinulose, not carinate, 27 in a longitudinal series, 

 7 between dorsal and adipose fin, 13 between anal and caudal. 

 Lower surface of head and abdomen naked, except for some small 

 scattered granules. Dorsal I 7 ; first ray a little longer than the 

 head, when laid back extending to the sixth scute behind the 

 last ray, which is less than \ as long as the first. Length of base 

 of dorsal equal to its distance from tip of spine of adipose fin. 

 Anal I 4. Pectoral spine extending to anterior i of ventral fin. 

 Caudal emarginate, the middle rays a little more than f as long 

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

 rounded pale spots on head and body ; fins dusky, the dorsal with 

 the posterior half of each interradial membrane blackish. 



Eab. Rio Piracicaba, San Paulo, Brazil. 



A single specimen, 160 mm. in total length, received from 

 Dr. R. von Ihering. 



Plecostomus strigaticeps, sp. n. (Plate XLYIIL fig. 1.) 

 Depth of body 5 in the length, length of head 34 to 3f. 

 Depth of head If in its length, breadth of head 1 to l\, length of 

 snout If to If, diameter of eye 5 to 5i, interorbital width 2|. 

 Length of mandibular ramus If in the interorbital width ; about 

 60 teeth on each side in both jaws. Barbel -^ to | the diameter 

 of eye. Snout broad, i-ounded ; supraoi'bital edges not or scarcely 

 raised ; temporal plates not keeled ; supraoccipital slightly convex, 

 without median ridge, bordered posteriorly by 1 or 2 scutes; 

 occipital process short. Scutes spinulose, not carinate, 26 in 

 a longitudinal series, 6 or 7 between dorsal and adipose fin^ 

 12 between anal and caudal. Lower surface of head naked except 

 for a granular patch in front of each gill-opening ; abdomen 

 nearly completely covered with granular scales except foi- a naked 

 area in front of each ventral fin.. Dorsal I 7, the first ray a little 

 shorter than the head, when laid back extending to the second 

 or third scute behind the last ray, which is ^ as long as the first. 

 Length of base of dorsal equal to its distance from the middle of 

 the "spine of adipose fin. Anal I 4. Pectoral spine extending 



