528 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



i. Cranium with ouly tlie median crest developed; anal rays 



about HI, 9 Epinephelus, 276. 



hhh. Maxillary unknown; "pyloric ccrca innumerable." 



Promicrops, 277. 



tt Brancliiostefjals 6; dorsal spines 10, tlie third filamentous Dules,278. 



** Anal spines obsolete or reduced to 2; scales very small, smooth. {Rhypticina.) 



j. Dorsal spines 2 or 3 only Rhypticus, 279, 



270.— CEI^TROPOMUS Lacepcde. 

 {Oxylabrax Bleeker.) 



(Lac<5pede, Hist. Nat. Poiss. iv, 248, 1802: type Sciavna uiuIecimaUs Bloch.) 



Body elongate, covered with rather small, ctenoid scales. Head 

 oblong-conical, depressed, lower jaw projecting ; teeth on jaws, vomer, 

 and palatines, all villiform, without canines; tongue smooth. Maxillary 

 with a strong supi3lemental bone. Preopercle serrated; two stronger 

 spines at its angle ; opercle without true spines; preorbital and supra- 

 scapular usually serrated. Dorsal fins entirely separated ; the first with 

 8 spines; the first and second spines usually much shorter than the 

 third. Anal fin short, with 3 spines, the second of which is long and 

 strong. Caudal forked. Lateral line conspicuous, extending on the 

 caudal fin. Branchiostegals 7. Sjiecies numerous, inhabiting tropical 

 seas. According to Professor Gill the skeleton of Centropomus differs 

 so widely from that of the other Serranoids that it should constitute a 

 separate family, {/.svrpo'^j spine ; najfj.a, operculum.) . 



a. Lat. 1. about 70; body elongate. 



879. C. ugGdecimalBS (Bloch.) Cuv. & Va].—Eohalo. 



Silvery, greenish above; lateral line black, very distinct; dorsal and 

 caudal dusky; other fins yellowish; ventrals without dusky area. Pre- 

 orbital nearly entire. Third dorsal sj^ine longer than the fourth; second 

 anal spine comparatively short, about as long as third. Air-bladder 

 anteriorly with two long, slender, backward-directed horns. Head 3; 

 depth 4J. D. VII-1, 9; A. Ill, G ; Lat. 1. 70. A large food- fish, abundant 

 in the West Indies; ranging northward to Lower California, Florida, 

 and Texas. 



{Sciwna inulccimnlis Bloch. Ichth. 303; Giinthcr, i, 79; Vaillant & Bocourt, Miss. Sci. 

 au Mex. iv, 17: Centropomus vlridh Lockiugton, Proc. Cal. Acad. Nat. Sci. 1877, 16.) 



271.— ROCCUS Mitchill. 



Bass. 



(ia&rax Cuvier, 1817 ; preoccupied in Chiridcp.) 



(Mitchill, Rept. part, Fish. N. Y. 1814, 25 : type lioccus siriaius Mitch. = Scia'na lin- 

 cata Bloch.) 



Body oblong or ovate, compressed and more or less elevated. Head 



