Jordan and Evermann. Fishes of North America. 2283 



spots at the base and a row of spots across the middle ; lining of maxillary 

 with bands of black and white. Bay of Guaymas ; 3 specimens known. 

 ds, eyed, from its ocellate dorsal.) 



Opisthognathus ommata, JENKINS & EVERMANN, Proc. TJ. S. Nat. Mus. 1888, 153, Guaymas. 

 (Type, No. 39640. Coll. Jenkins & Evermann.) 



842. GNATHYPOPS, Gill. 



Gnathypops, GILL, Proc. Ac. Nat. Sci. Phila. 1862, 241 (maxillosus) . 



This genus differs from Opisthognathus in having the maxillary of medium 

 length and truncate behind, not extending to edge of opercle ; caudal mod- 

 erate, rounded behind. Species in form and habit agreeing closely with 

 those of Opisthognathus. (yraQos, jaw; vito, below; ooif}, eye.) 



a. Body and fins spotted with black and often with pale. 

 b. Dorsal fin with a conspicuous dusky blotch in front. 



c. Scales very small, about 120; dorsal rays 26. SCOPS, 2619. 



cc. Scales moderate, about 65 ; dorsal rays 15. MAXILLOSA, 2620. 



bb. Dorsal tin without distinct blotch in front; scales small, about 100. 

 d. Dorsal rays about XI, 16 ; dark spots on head and body few. 



MACROPS, 2621. 

 dd. Dorsal rays about XI, 13; dark spots on head and body numerous. 



e. Dorsal tin distinctly notched; lateral line not reaching middle of 

 dorsal. RHOMALEA, 2622. 



ee. Dorsal tin not notched ; lateral line reaching middle of dorsal. 



SNYDERI, 2623. 



aa. Body and tins nearly uniform olive ; the spots few and spare ; dorsal rays 24 ; scales 

 100 ; no black on membrane of maxillary. MYSTACINA, 2624. 



2619. GNATIIYPOPS SCOPS, Jenkins & Evermann. 



Head 3; width of head 5f, its depth 4|. D. 26 (X, 16) ; A. 19 (II, 17); 

 scales 3-122-40. Scales small, none on iiead; lateral line extending to 

 about middle of dorsal fin; mouth large; maxillary extending beyond eye 

 a distance 4 T V in head ; snout 6| in head ; teeth in bands, outer series on 

 upper jaw rather strong; a single tooth on vomer; gill membranes con- 

 nected. Opercle ending in a long flap, which extends upward and back- 

 ward, nearly meeting over the back in front of the dorsal fin. Eye large, 

 2 in head ; interorbital space narrow, 11 in head. No depression between 

 the dorsal spines and the soft rays, which are scarcely distinguishable; 

 height of dorsal equal to that of anal ; ventrals inserted in front of pec- 

 torals; pectorals equal to ventrals in length, 7 in body; caudal rounded. 

 Coloration, in alcohol : Body pale, covered with many dark spots about 

 the size of 3 to 6 scales; top of head, with smaller dark spots; sides of 

 head with whitish spots; dorsal fin with a black ocellated spot equal to 

 eye on the space between second and fifth spines; remainder of fin dark, 

 with many white spots running into each other on some portions, so as to 

 form irregular lines ; base of anal pale, the outer edge black ; caudal dark 

 with 2 whitish spots at the base, and a row of 6 white spots across the 

 middle on alternate rays; pectorals lighter, with small whitish specks; 

 ventrals dusky ; belly pale. Guaymas ; 3 specimens known, respectively 

 115 cm., 10 cm., and 7 cm. in length to base of caudal. This species is the 



