Jordan and Evermann. Fis/its of North America. 1201 



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

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

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

 to 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 

 Centropristcs striatiis, 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/cw^, swift ; ovpd, 

 tail.) 



Serram<s trifurcus, JORDAN & GILBERT, Synopsis, 534, 1883; not Perca Irifnrca, LINNAEUS. 



Scrraint* oeyiirug, JORDAN & EVERMANN, Proc. U. S. Nat, Mus., 468, 1886, Snapper Banks off 



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

 Centropristi* oct/nrw>, JORDAN & EIGENMANN, Z. c., 392, 1890. 



Subgenus TRILOBURUS, Gill. 



1589. CENTROPRISTES PHILADELPHICUS (Linnaeus). 

 (ROCK SEA BASS.) 



Head 2f to 2* ; depth 3J- to 3f . D. X, 11 ; A. Ill, 7 ; P. 17; C. 18 ; scales 

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

 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; serrse 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 -f- 10 in number. First 2 dorsal 

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

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

 spine 3g 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 striatus, 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 ($ to H), the lower rays about head. A young specimen, 5 



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

 F. N, A; 77 



