2l8 HELLER AND SNODGRASS 



Description of the Type. Head three and two thirds in length ; 

 depth three and two fifths ; eye three and one half in head ; maxillary 

 three; interorbital two in eye; D. XXI, n ; A. II, 20; scales 63. 



Shape of the head and body much as in M. delalandi, body pos- 

 teriorly compressed and with dorsal profile little elevated. Mouth 

 small, terminal ; jaws equal and armed with a single series of incisor 

 teeth ; vomer with a semicircular patch of similar teeth. Maxillary 

 short, extending to vertical from anterior border of eye. Nape with 

 an oblique patch and the eye with a smaller supraocular patch of fila- 

 ments. Diameter of the eye slightly less than length of snout. 



Scales cycloid, small, sixty-three in lateral line, head, breast, median 

 line of belly, and bases of the ventral fins naked. 



Dorsal fin long, beginning at nape and extending nearly to caudal 

 fin. Spinous dorsal high anteriorly, notched between fourth and fifth 

 spines and again between nineteenth and twentieth, the first spine high, 

 one and three fourths diameter of eye and considerably longer than 

 second spine ; last spine about as high as third. Soft dorsal higher 

 than the spinous, second ray highest, but little exceeding the other 

 rays ; last ray reaching two thirds the distance to caudal. Anal fin long, 

 not extending quite as far posteriorly as dorsal, deeply incised ; spinous 

 portion short; soft part longer, the twelfth to the fourteenth rays 

 longest. Pectorals rounded, rays fourteen, median longest. Caudal 

 rounded, rays thirteen. Ventrals composed of three deeply incised rays. 



Coloration in Life. Above, light olive, sides with five broad 

 olive-brown bands, breaking up ventrally into blotches, above the 

 median line of the sides the dark bands separated by light purplish 

 areas spotted with brownish, below the median line these areas become 

 tawny-brown ; head olive, rufous-blotched, opercle with a large 

 circular dark blotch ; underparts whitish, barred and spotted, the bars 

 about as wide as the interspaces ; branchiostegal membrane and throat 

 very regularly barred ; dorsal fin amber-yellow, with rufous spots and 

 red-tipped spines and rays ; pectoral membrane lighter, golden-yellow ; 

 rays rufous-spotted, lower dark red; ventrals whitish like belly, 

 brown-barred, rays red-tipped ; anal fin lemon with brown spots and 

 red-tipped rays ; caudal fin like dorsal in coloration ; iris crimson. 



This species is close to M. delalandi of the mainland from which 

 it differs in the possession of more than twenty dorsal spines, in the 

 higher first dorsal spine, and in the barred lower parts. We have ex- 

 amined twenty specimens of M. delalandi from Mazatlan, Mexico, 

 and find the following variations in the fins ; dorsal XIX-XX, 10-12 ; 

 anal II, 18-19. O ur Galapagos material gives the following formulaB : 



