NATURAL SCIENCES OF PHILADELPHIA. 147 



The color is greenish, tinged with brassy and with lighter areas in the centres 

 of the scales on the sides, which form faint, uninterrupted lines. There are 

 six transverse dorsal bands ; the first almost obsolete before the dorsal fin ; the 

 second under the third to fifth spine; the third under sixth to eighth; the 

 fourth under the tenth to twelfth ; the fifth under the anterior half of the soft 

 portion, and the sixth behind the fin. 



Length from snout to end of median caudal rays (3-J) 100 



Body Greatest height ." 43, 45^ 



Height behind vertical fins 18 



" of caudal peduncle 15 



Greatest thickness 17 



Head Length laterally 25 



Height at preopercular margin 30 



" at pupil 25 



" of preorbital at end of jaw 3J 



" " at highest part 4| 



Length of snout 9~ 



Length of operculum 8f 



Height of operculum and suboperculum 20 



Width of interorbital area 9^ 



Eye Diameter 9" 



Dorsal Origin from snout 27 



Length of base 3914 



Height at first spine 5 



" " fifth spine (10)-13 _ 



" " last spine 8,10 



" " longest ray 18 



" " last ray 7 



Anal Origin from snout 57 



Length of base 19 



Height at first spine 5 



" " second spine 11 



" " longest ray , 18 



" " last ray 7 



Caudal Length of median rays 18 



" " longest ray 25 



Pectoral Length 22 



Ventral Length of spine 11 



" " firstray 22 



Seven specimens of this species, varying between nearly two and four inches 

 were obtained by Mr. Xantus. 



Genus HYPSYPOPS Gill. 



This genus, framed for Glyphidodonle, with elevated preorbital bones and 

 entire teeth, is rather allied to Pomacentrus than to Glyphidodon, the technical 

 character bringing its species in the latter genus, being of less real value than 

 the dentition or development of the suborbital bones. 



Hypsypops dorsalis Gill. 



The height much exceeds a third (-37) of the extreme length. The head is 

 rather depressed in front of the nape and very steep in front of the eyes ; it 

 forms nearly a quarter (-23) of the total length ; its height at the vertical of 

 the preoperculum much exceeds the length (-28), and that at the pupil is less 

 (21). The length of the snout equals two-fifths of the latter height (-8i), is 

 about a quarter more than the height of the preorbital bone (6), which itself 

 is not much less than the diameter of the eye (-7). The preoperculum is per- 

 fectly entire, and the teeth of the jaws truncated. 



1862.] 



