NATURAL SCIENCES OP PHILADELPHIA. 67 



ameter of the eye ; cheeks longer than high. Nostrils approximated, simple. 

 Pre.operculum esinuate, pectinated. Operculum with a blunt, bony projection 

 behind. Suboperculum narrow. 



Mouth moderate, with the cleft little oblique. Jaws even ; sitpramaxillaries 

 nearly straight behind, and subtruncated at end. Lips thick, the lower attached 

 by a frsenum in front. 



Teeth on the jaws alone, in a broad, villiform band in front, preceded by a 

 row of larger acute ones continued to the corners of the mouth ; the hindmost 

 teeth enlarged canines directed forwards. 



Branchiostegal rays six. (Branchial membrane well developed, and free 

 below.) 



Dorsal fin with seven or eight graduated, pungent spines, and rather nu- 

 merous (2227) uniform branched rays ; antepenultimate normally longest. 

 Anal similar to^the soft dorsal, armed with one or two pungent spines ; first 

 spine, when present, extremely small. 



Caudal fin emarginated, with its lobes pointed. 



Pectoral fins well developed, longer than the ventrals. 



Ventrals thoracic or subbrachial, with the spine slender but acute, and with 

 second ray longest. 



Type Caulolatilus chrysops Gill. 



The genus Caulolatilus is widely separated from Latilus by the form of the 

 body, structure of the scales and especially by the form of "the head and the 

 structure of the fins. It is also related to Prohitilus,* but is readily distin- 

 guished by the general form, the form of the head, the thoracic position of 

 the ventral fins, as well as the number of dorsal spines and form of the cau- 

 dal fin. 



Caulolatilus was first separated from Latilus in an article entitled " Remarks 

 on the relations of the genera, and other groups of Cuban Fishes ;" it was 

 said to be distinguished by its form and the structure of the fins, and was 

 founded for the reception of the Latilus chrysops C. et V. 



Subsequently Dr. Cooper described as a new generic type allied to Hetero- 

 gnathodon Blkr., a Californian species of the same genus, and considered it "to 

 be a very aberrant form of the Percoid family, having many characters of 

 other orders. 



Four species of the genus are known to me ; their relations and differential 

 characters may be expressed by the following scheme : 



I. D. vii (-viii.) 24. A. i. (ii.)22.f Profile quadrantiform. C. chrysops. 



C. affinis. 



II. D. viii. 2526. A. ii. 2526. Profile less decurved, the 



snout being produced. 



a.. Dorsal spines behind longer than the space between the 

 fin and lateral line ; pectoral fin equal to distance 

 from snout to middle of operculum C. anomalus. 



p. Dorsal spines behind about equal to space between fin 

 and lateral line ; pectoral fin about three-fourths the 

 length of the head (Jenyns.) C. princeps. 



Caulolatilus chrysops. 



Latilus chrysops C. et V., ix. 496 ; Guict., in Sayra,, tab. 2, f. 1 ; Gthr., ii. 

 253. 



* Prohitilus Gill, (type Latilus Jugularis Cuv, Val.,) is distinguished by its general form, a 

 well as the form of the head, scaly forehead aud approximated eyes ; few (4) dorsal spines, entire 

 caudal and subjugular ventrals. 



+ My own enumeration of the dorsal and anal ray exactly coincides with Gunther's; Cuvier as- 

 signs D. -viii. 24. A. ii. 22. I cannot discover the small spine in front of the anal one, and there 

 are certainly only seven dorsal spines, 



1865.] ' 



