FISHES OF THE FAMILY LORICARIID®. 225 
B. Interoperculum armed with bristles; length of mandibular ramus less than interorbital 
width, 
1. Dorsal with I 7 rays. 
a. Length of base of dorsal nearly equal to its distance from the caudal. 
eet width 34-35 times in the length of head; caudal peduncle 
4 times aslongasdeep . . . . : : - «20. A. barbatus'C.& V. 
ea width 4 times in the length of te ad ; edoanl redtaale 
23 times as long as deep - 28. A. depressus Gthr. 
b. Length of base of dorsal nearly equal to its distance 
fromthe adipose fin. . . . . . .. . . . 29. A. guentheri Regn. 
2. Dorsal with I 9-10 rays. 
D.19. 24 scutes in a longitudinal series. . . . . . . . . 80. A. angulicauda Stdr, 
D.110. 25-27 scutes in a longitudinal series . . . . . . . 81. A. parahybe Kigenm, 
1. ANCISTRUS ANNECTENS, sp.n. (Plate XI. fig. 2.) 
Depth of body 43-5 times in the total length, length of head about 31 times. 
Head 15-1} times as long as broad and 14-13 times as Due as deep. Diameter of 
eye 7-8 times in the length of head, interorbital width 24-22 times, length of snout 
12 times. Length of mandibular ramus 3 times in the a width. Snout 
narrowed anteriorly; supraoccipital with strong median ridge; supraorbital edges 
raised; temporal plates carinate; interoperculum armed with 5 or 6 slender spines, 
the longest equal to % the length of head. Scutes spinulose, the anterior and upper 
ones carinate, 26-27 in a longitudinal series, 7-S between dorsal and adipose fin, 
13 between anal and caudal. Supraoccipital bordered posteriorly by a median scute 
and by one on each side; two series of scutes between the nuchal and posthumeral 
series. Lower surface of head and abdomen completely covered with small granular 
scales. D. I 7, the first ray equal to the length of head, the last } as long; length of 
base of dorsal greater than its distance from the adipose fin. A.I4. Pectoral spine 
extending beyond base of ventral. Caudal emarginate, the outer rays produced. 
Caudal peduncle 33-5} times as long as deep. Dark spots on head, body, and fins; 
dorsal with a series of especially large and distinct spots, one at the base of each 
interradial membrane. 
Total length 280 mm. 
Two specimens from St. Javier and the Rio Durango, N.W. Ecuador, collected by 
Mr. Rosenberg, referred by Boulenger to Plecostomus bicirrhosus, 
I have given this species the name “annectens”’ because it has the general form 
of Plecostomus gquacari and of the species of the old genus Pterygoplichth i and 
whilst agreeing with the former in the number of dorsal rays, has the movable inter- 
operculum of the latter. 
2H 2 
