276 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



equal to distance from same point forward to middle of eye. Length of 

 opercle, from anterior ridge of preopercle, three-fourths its greatest 

 height. 



Insertion of dorsal midway between base of caudal and mftldle of eye 

 [caudal and dorsal fins nearly destroyed in type] ; anal comparatively 

 short and posterior, its insertion midway between gill-opening and base 

 of caudal, its rays between 20 and 24 in number [two or three of the 

 posterior rays destroyed by a string which has been tied around the 

 tail in the type specimen]. Anal fin with a large scaly sheath. Ven- 

 trals small, inserted midway between base of caudal and front of eye. 

 Pectorals short, not reaching veutrals. 



Scales large, rather adherent [those on anterior part of body lost] j 

 about 8 in a vertical series from last ray of dorsal to anal. 



Head 3 in length ; depth, 4. Anal rays about 23. 



Color, bluish above ; middle line of back dark ; sides and below bright 

 silvery, the cheeks and opercles especially so ', no trace of lateral silvery 

 stripe. 



The type of this species, 5 inches in length, was taken from the stom- 

 ach of a specimen of Cynoscion othonopterum at Punta San Felipe, Mex- 

 ico. It has suffered somewhat from the digestive process, but the head 

 is in perfect ijreservation, and all points essential to the description can 

 be readily made out. This species seems to us most closely related, 

 among described species, to 8. macrolepidotus^ from which it diifers in 

 very many respects. 



29,372. Caulolatilus princeps (Jenyns) Gill. Punta Santa Teresa (in 



deep water). 

 29,370. Balistes polylepis Bteind. Same locality. 

 29,382. Opisthognathus rhomaJcus sp. nov. Santa Maria. 



(Subgenus Gnathypops Gill; allied to Gnathypops papuensis Bleeker.) 



Body rather robust, compressed ; head very large, ovoid, thicker and 

 deeper than body, with swollen cheeks, the occipital region high, the snout 

 somewhat truncate, the iutermediate profile forming a nearly even curve ; 

 greatest depth of head equal to its thickness and two-thirds its length. 

 Eye not very large, 6 in head, longer than snout, about equal to the width 

 of the flattivsh interorbital space. 



Mouth large, the maxillary extending well beyond eye, but not to the 

 margin of the preopercle nor to the man dibulary joint, its posterior margin 

 truncate ; supplemental bone small, but distinct ; length of maxillary 

 from end of snout If in head. Teeth moderate, in both jaws, in broad 

 bands which become narrow on the sides ; outer series of teeth some- 

 what enlarged, especially in upper jaw ; one rather small, blunt tooth 

 on middle of vomer. Gill-membranes scarcely connected. 



Head naked. Scales on body small, smooth, somewhat imbedded; 

 breast naked. Lateral line indistinct, ceasing opposite anterior third of 

 second dorsal ; 103 scales in a longitudinal series from head to caudal. 



md 



