Jordan and FA'ermaiin. — Fishes of North America. 1201 



mottled, the tips of its rays dusky; ventrals dusky; pectorals entirely 

 pale; caudal fiu with its upper and lower lobes filamentous, much pro- 

 duced, the middle rays still longer, exserted for a distance nearly equal 

 to I length of head, the total length of the longest ray being half the 

 length of the body. Gulf of Mexico, in rather deep water ; known from 

 the Snapper Banks off Pensacola. In spite of the striking differences 

 in color, in which this species considerably resembles the very young of 

 Centroprisk-s striatus, the details of form and structure are almost identi- 

 cal in the two species, the most notable difference being in the gill rakers. 

 Here described from the type, 10^ inches in length. (w/ciV, swift ; obfjd, 

 tail.) 



Serramis trifarcnf:, Jordan .t Gir.nEUT, Synopsis, 534, 1883; not I'ercn trifmcn, Linn.eus. 

 Sen-amis ocyitrus, Jordan & Evkkmann, Proc. U. S. Nat. Mus., 408, 1880, Snapper Banks off 



Pensacola. (Type, No. 37997. Coll. Silas Stearns.) 

 Cenlroprislis oci/urus, Jordan S; Eioenm.\nn, I. c, 392, 1890. 



Subgenus TRILOBURUS, Gill. 



1589. < KNTBOPRISTES PHILADELPHICUS (Liunajus). 

 (Bock Sea Bass.) 



Head 2| to 2i ; depth 3^ to 3J. D. X, 11 ; A. Ill, 7 ; P. 17; C. 18 ; scales 

 5-52 to 55, 15 pores. Maxillary reaching posterior margin of pupil, 2J 

 in head; mandibular band of teeth becoming a single series laterally ; a 

 few inner teeth in the front of each jaw enlarged ; lower jaw with the 

 inner series laterally and the outer series anteriorly of enlarged conical 

 teeth, the lateral teeth but little larger than those in front ; outer series 

 of upper jaw much enlarged, becoming smaller laterally, those in front 

 larger than any in lower jaw ; patch on vomer crescent-shaped; on pala- 

 tines long and narrow. Head naked forward from occiput, including 

 suborbital ring, snout, preorbital, top of head, maxillary, and lower Jaw; 

 scales on cheeks small, in 9 to 11 very regular oblique series ; scales on 

 opercles as large as those on body, in 8 or 9 oblique series, those on the flap 

 again smaller; least interorbital width about * diameter of eye, which is 

 4f in head ; serra) on and below preopercular angle slightly enlarged and 

 more distant than those above ; subopercle and interopercle finely, evenly 

 serrate. Gill rakers ^ length of eye, 3 -|- 10 in number. First 2 dorsal 

 spines short, the third and fourth nearly equal, the fourth | or nearly J 

 head; the last spines are then much shortened, forming a notch, the last 

 spine 3.1 in head, f the ray following; membrane deeply incised between 

 the spines, the upper angles produced beyond the spines in long, narrow 

 filaments, very variable in length, usually less than diameter of orbit; 

 the spines themselves are acute-;* the structure of the dorsal thus does 

 not differ from that of Centropristes striatns, which has also a trifurcate 

 tail. Caudal with the upper and middle rays much produced and nearly 

 equal, the lower lobe but little lengthened ; median rays nearly as long 

 as head {i to \i), the lower rays about i head. A young specimen, 5 



*Not at all filamentous, as figured by Holbrook (Iclith. S. C, pi. 7, fig. 1). 

 F.N, A. 77 



