354 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



Upper lip double laterally only for a 

 short distance. 



Eye not especially near dorsal outline, 

 very small, 5.6 in head, 2.1 in snout. 

 (Difference shown in this and opposite 

 paragraph probably not significant, 

 because of difference in size of speci- 

 mens.) 



Color plain j'-ellowish gray; no dark 

 markings anywhere; fins plain. (No 

 dark markings mentioned in descrip- 

 tion of fresh specimen, which was 

 bluish.) 



Upper lip double throughout, the inner 

 one narrow anteriorly in the largest 

 specimen (probably changing with 

 age). 



Eye near dorsal outline, larger, 3.9 to 

 4.4 in head, 1.2 to 1.45 in snout. 



Color dark gray above, paler gray 

 below; with dark bar on chin and 2 on 

 lower part of head; pectoral with a 

 dark bar at base; caudal, anal, and 

 ventral with dark spots or specks. 



Range. — Known only from Lobos de Afuera Bay, Peru. 

 Genus XENOSCARUS Evermann and Radcliffe, 1917 



Body elongate, compressed, moderately robust; head rather flat 

 above, somewhat conical; mouth moderate; lower jaw included; teeth 

 white, distinctly outUned, in regular obUque series, attached to outer 

 surface of dental plate, the cutting edge not continuous, being formed 

 in part at least of individual teeth; lower pharyngeal plate about 3 

 times as broad as long; upper pharyngeal plates notably longer than 

 broad; each plate provided with transversely broadened teeth, each 

 tooth with a narrow cutting edge; upper lip double throughout; gill 

 membranes broadly united, and attached to isthmus; lateral line more 

 or less interrupted; dorsal with 9 spines and 10 soft rays, the spines 

 flexible. 



A single species is known, which has been recorded only from Peru. 



XENOSCARUS DENTICULATUS Erermann and Radcliffe 



PococHO DE mar; Loro del mar 



Xenoacarus denticulatus Evermann and Radcliffe, 1917, p. 129, pi. 12, fig. 1, 

 Lobos de Afuera, Peru (original description). 



Head 3.3 to 3.6; depth 2.8 to 3.2; D. IX, 10; A. Ill, 9 (rarely 8); 

 P. 13; scales 24 or 25; vertebrae 24 (one specimen dissected). 



Body compressed, rather robust, its greatest thickness nearly half its 

 depth; dorsal and ventral outlines anteriorly about evenly convex; 

 caudal peduncle rather long, 1.9 to 2.3 in head; snout somewhat 

 conical, 2.3 in large examples to 3.2 in small ones; eye 3.5 to 5.7; inter- 

 orbital flat, 3.2 to 4.0; mouth horizontal ; lower jaw included; maxiUary 

 not quite reaching eye, concealed under skin of preorbital, 2.7 to 3.3 

 in head ; teeth not fully coalesced, in about five obUque series in each 

 jaw, the individual teeth forming the cutting edge; no free lateral 

 canines; lower pharyngeal plate about three times broader than long, 



