170 BULLETIN 18 9, UNITED STATES NATIONAL MUSEUM 

 MYCTEROPERCA XENARCHA Jordan 



Mycteroperca xenarcha Jordan, 1887, p. 387, James Island, GaMpagos; Paita, 

 Peru (original description). — Walford, 1936, p. 7 (M. houlengeri Jordan 

 and Starks synonymized; description); 1937, p. 103, pi. 11, figs a-c (diag- 

 nosis of 3 color phases). 



Mycteroperca houlengeri Meek and Hildebrand, 1925, p. 448, Corozal, Canal 

 Zone (references; description; range). 



Head 2.6; depth 2.9 to 3.1; D. XI, 15 or 16; A. Ill, 10 or 11; P. 16 

 or 17; scales too small to enumerate accurately, about 100 to 108. 



Body fairly compressed, its greatest thickness only about half its 

 depth; back moderately elevated; dorsal profile anteriorly slightly 

 convex; caudal peduncle well compressed, 2.8 to 3.4 in head; snout 

 pointed, 3.6 to 4.4; eye 5.7 to 6.5; interorbital 4.25 to 6.9; mouth 

 large, oblique; lower jaw strongly projecting, entering dorsal outline; 

 maxillary moderately broad, with a small supplemental bone, reach- 

 ing to or beyond vertical from posterior margin of pupil, 2.2 in head; 

 teeth in upper jaw in a narrow band, a few moderately developed 

 fixed canines anteriorly, the outer series laterally slightly enlarged, 

 fixed, the inner teeth depressible, those of lower jaw as in upper jaw 

 though reduced principally to 2 rows, bands of minute teeth on vomer 

 and palatines; vertical margin and angle of preopercle finely serrate, 

 the serrae at angle only slightly enlarged, the horizontal limb mostly 

 smooth; gill rakers moderately slender, those at angle about three- 

 fourths length of eye, 20 to 23 more or less developed on lower and 

 9 to 12 on upper limb of first arch; scales small, ctenoid, but becoming 

 cycloid anteriorly above lateral line, on head and on chest, extending 

 on snout, maxillary, and mandible; dorsal spines rather slender, the 

 fourth 2.8 to 3.4 in head, decreasing slightly in length behind the 

 fourth, a few soft rays, some produced, forming a pointed lobe; caudal 

 truncate to emarginate, the membranes between the rays scalloped, 

 some of them deeply incised in large specimens, scallops shallow in 

 young, giving the margin an uneven or a jagged appearance; anal 

 spines moderately strong, graduated, apparently becoming propor- 

 tionately shorter with age, the second 4.1 to 7.2 in head, the middle 

 rays of anal somewhat produced, forming a pointed lobe; ventrals 

 very close together, inserted slightly behind base of pectorals, the 

 inner ray attached to the body by a thin membrane, the spine slender, 

 3.1 to 3.9 in head; pectoral inserted under or a little in advance of 

 origin of dorsal, with round margin, reaching about to tip of ventral, 

 1.6 to 1.8 in head, 4.3 to 4.8 in length. 



Three color phases have been described by Walford (see references 

 above) as follows: "The gray phase is plain gray or brown, without 

 spots or contrasting marks of any sort. * * * xhe pinto phase 

 is grayish green, the body covered with irregular round and oblong 



