256 ME. C. TATE EEGAN ON THE 



6. Xen t ocara cirrhosa. 



Hypostomus cirrhosus Cuv. & Val. Hist. Nat. Poiss. xv. p. 511 (1840) ; Val. Voy. d'Orbigny, 



Poiss. pi. vii. fig. 3 (1847). 

 Ancistrus cirrhosus Kner, Denkschr. Ak. Wien, vii. 1854, p. 272 ; Eigenm. & Eigenm. Proc. Cal. 



Ac. (2) ii. 1889, p. 47, and Occ. Pap. Cal. Ac. i. 1890, p. 446. 

 Cheetostomus variolus Cope, Proc. Ac. Philad. 1871, p. 288. 

 Chcetostomus cirrhosus Giinth. Cat. Fish. v. p. 247 (1864). 



Depth of body 5-5-f times in the total length, length of head 2-|-2f times. Head 

 !-§- times as long as broad and 2j times as long as deep. Diameter of eye 6f— 8 times 

 in the length of head, interorbital width 2-j— 2f times, length of snout lf-lf times. 

 Length of mandibular ramus 2f— 2f times in the interorbital width. Snout with 

 tentacles. Interoperculum armed with 9-13 spines, the longest \ the length of head. 

 23-24 scutes in a longitudinal series, 6-7 between dorsal and adipose fin, 10-12 

 between anal and caudal. D. I 7, the first ray equal to §— f the length of head, 

 the last ray, when laid back, nearly or quite reaching the spine of the adipose fin ; 

 length of base of dorsal about equal to its distance from middle of spine of adipose 

 fin. A. I 4. Pectoral spine extending a little beyond base of ventral (young) or 

 nearly to its middle (adult). Caudal obliquely truncate, the lowest ray -f-f- the length 

 of head. Caudal peduncle 2f— 2f- times as long as deep. Rather large light spots on 

 head and body, usually so close together that the ground-colour appears as a network 

 of dark lines ; fins with dark spots which may be confluent to form cross-bars ; a dark 

 spot at the base of the first interradial membrane of the dorsal. 



Total length 140 mm. 



Eight specimens (including the types of the species) : Ii. Paraguay ; R. Amazon ; 

 Guiana ; Trinidad. 



7. Xenocara chagresi. (Plate XIV. fig. 7.) 



Ancistrus chagresi Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 47, and Occ. Pap. Cal. Ac. 

 i. 1890, p. 446. 



Depth of body 5 times in the total length, length of head 2f times. Head l^-T-9 

 times as long as broad and If times as long as deep. Diameter of eye 7-j-S-g- times in 

 the length of head, interorbital width 2\ times, length of snout T§- ( 3 )-l-f ( ? ) times. 

 Length of mandibular ramus 2f times in the interorbital width. Snout with tentacles ; 

 interoperculum armed with about 10 spines, the longest equal to ■§—§■ the length of 

 head. Scutes spinulose, not carinate, 24 in a longitudinal series, 7 between dorsal and 

 adipose fin, 11 between anal and caudal. D. 1 7, the first ray equal to f— J the length 

 of head, the last ray, when laid back, separated by 2 scutes from the spine of the adipose 

 fin ; length of base of dorsal equal to its distance from the anterior part of the spine of 

 the adipose fin. A. I 3-4. Pectoral spine stout, extending a little beyond the base 

 of ventral. Caudal obliquely truncate, the lowest ray equal to f (larger specimen)-!- 



