REVIEW OF THE SERRANID^. 
367 
41. MYCTEROPERCA OLPAX. 
(Yellow Grouper.) 
a. Green variety {olfax). 
Serranus olfax Jenyns, Zool. of the Beagle, Fishes, 9, pi. 4, 1840 (Galapagos Islands) ; Giinther, Proc. 
Zool. Soc. London, 1877, 67. 
Mtjcteroperca olfax Jordan & Swain, Proc. U. S. Nat. Mus., 1884, 376 (copied) ; Jordan, Proc. U. S. 
Nat. Mns., 1884 (Abingdon Island, Galapagos ; Panama). 
^ C 0. Red variety {rubemma). 
Mycteroperca olfax ruberritna Jordan & Bollman, var. nov. (Abingdon Island). 
Rahitat. — Galapagos Islands ; Panama. 
Etymology. — Olfacto, to smell, from the large size of the nostrils. 
This species is well represented in the mnsenm at Cambridge, some of the speci- 
mens there being 2 feet in length. The following description is taken from No. 
24198, M. C. Z., 2 feet long, from James Island, Galapagos : 
Head 2^^ to 3 in length; depth, 3J. D., XI, 17 ; A., HI, 11. Scales, 30-120-x. 
Body robust, not strongly compressed ; head deep, the snout rather sharp, the an- 
terior profile steep; mouth large, the maxillary reaching somewhat beyond eye, 24 in 
head, its surface scaly, as in other species; teeth moderate; canines normal; nostrils 
large, very close together, separated by a narrow vertical septum, the posterior some 
three times the diameter of the anterior, which is broader than the septum (in the dried 
example examined by Jenyns the anterior nostril seems to have been overlooked, and 
a horizontal basal membrane in the posterior nostril was taken for the nasal septum) ; 
eye small, 7 in head ; preorbital as broad as eye; interorbital area flattish and broad, 
4§ in head; gill-rakers coarse and long, x-p 15; preopercle without salient angle, its 
notch moderate; scales small, chiefly cycloid. 
Dorsal spine strong, the second and third elevated so that the posterior outline of 
the fin is concave, first spine just half the second, second and third equal, 2| in head, 
fourth IJ in third ; soft dorsal scarcely angular ; caudal flu shallow-lunate ; soft anal 
falcate, its posterior margin concave, the longest rays 2J in head (its form as in the 
adult of rosacea, falcata, xenarcha, and rubra). 
Color brown, with some traces of grayish vermiculations around small round brown 
spots ; flns all dusky, especially distal ly. 
Young covered all over with round brown spots, much smaller than the pupil ; a 
black mustache; pectoral with a narrow pale edge. 
A large specimen taken by the Albatross at Abingdon Island, in the Galapagos, 
seems to have been bright red in life. It probably represents a deei)-water variety 
analagous to the red varieties of West Indian species. It may be distinguished as var. 
ruberrima. The anal is a little lower than in an equally large specimen of the typical 
olfax taken in the same locality. No other difference is apparent. 
