262 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



abnormal anteriorly with the second and third spines fused. How- 

 ever, a groove between them may be detected. ,A combination of 

 the numerous dorsal spines, rather numerous anal rays, the rather 

 small scales, and the short pectoral fin distinguish this species from 

 other local forms. It is not evident from the description of M. 

 ophicephalus (Jenyns), based on poorly preserved specimens from 

 Chile, wherein it differs from the present species. This cannot be 

 determined until specimens from Chile become available for study. 

 Range. — Known only from Peru. 



MENTICIKRHUS PANAMENSIS (Steindachner) 

 MUCHACHITA 



Umbrina panamensts Steindachner, 1875c, p. 9, pi. 9, figs. 1, 2, Panama (origi- 

 nal description). 



Mentieirrhus panamenszs Evermann and Radcliffe, 1917, p. 106, Capon, region 

 of Tumbes, Peru (synonymy; description). — Meek and Hildebrand, 1925, 

 p. 669, Panama Bay (synonymy; description; range). 



Head 3.0; depth 4.0; D. X-I, 21; A. I, 9; P. 21; scales 61. 



Body quite elongate, somewhat compressed, its greatest thickness 

 nearly three-fourths its depth; back elevated; ventral outline nearly 

 straight; head low, its width and depth about equal at margin of 

 preopercle; caudal peduncle well compressed, 3.4 in head; snout 

 somewhat conical, projecting about half an eye's diameter beyond 

 premaxillaries, 3.4 in head; eye small, 7.2; interorbital 4.2; mouth 

 inferior, horizontal; lower jaw included; maxillary reaching below 

 posterior margin of pupil, 2.9 in head; teeth in a band in each jaw, the 

 outer ones in upper jaw notably enlarged, the rest very small, smaller 

 than those of lower jaw; margin of preopercle with very small and 

 rather few membranous serrae ; gill rakers obsolete ; lateral line some- 

 what arched anteriorly, becoming horizontal somewhat behind base of 

 anal; scales moderate, strongly ctenoid, apparently not extending 

 on bases of dorsal and anal fins, very slightly on ventral, but to a 

 greater extent on pectoral, extending on at least basal half of inter- 

 radial membranes of caudal, the rows anteriorly about parallel with 

 lateral line, becoming oblique under first dorsal, and horizontal under 

 second dorsal, 6 rows between lateral line and first dorsal spine, 24 

 vertical series on side between origin of anal and base of caudal; dorsal 

 fins close together, the spines moderately slender, the third the longest, 

 2.0 in head (variable in length according to specimens from Panama), 

 the ninth and tenth very short; second dorsal, somewhat elevated 

 anteriorly ; caudal very slightly concave above lateral line, the longest 

 rays below lateral line; anal with convex margin, the spine very weak, 

 adhering closely to first soft ray, its point not free, origin of fin rather 

 nearer vertical from end of dorsal base than base of ventral spine; 

 ventral inserted somewhat less than an eye's diameter behind base 

 of pectoral, 2.0 in head; axillary process of ventral small, bluntly 



