506 PROCEEDINGS OF THE ACADEMY OP 



The head has the same form as in the typical species ; the curvature above is 

 very slight. Its length forms less than* a quarter (23-100) of the total; the 

 length of the snout or interval between the symphisis of the upper jaw and the 

 eye exceeds an eleventh (.9i-100) of the same; that of the exposed operculum, 

 4-100. The height at the occiput equals a ninth (11-100) of the total length, 

 or nearly half (11-23) of the head's; the width is much less than the height 

 (9J-100), and regularly diminishes towards the snout, where it equals a half of 

 the greatest. The interorbital area is perfectly flat, and its width exceeds the 

 length of the operculum (.04J). 



The eyes are nearly central and oval ; the long diameter is contained more 

 than eighteen times in the total (.05^) or four times in the head's ; the short di- 

 ameter twenty-five times (4. 100) in the former and nearly six times in the 

 latter. 



The scales on the crown and forehead, as well as on the cheeks and opercula, 

 are ctenoid. 



The mouth is very small; the periphery of each jaw semi-elliptical; the 

 lower jaw is received within the band of teeth of the upper. 



The teeth are uniform, and in a moderately broad band on each jaw and on 

 the vomer. 



The first dorsal fin commences at the end of the third tenth of the total length ; 

 its second and third spines are longest and nearly equal an eighth of the total 

 length (8-100); the first and fifth are nearly equal ; the outline thence declines 

 with a slight curve to the twelfth. 



The second dorsal fin regularly diminishes in height from front to rear ; the 

 second or first branched ray equals a tenth (10-100) and the penultimate a 

 twenty-second (4J-100) of the total length. 



The anal fin commences before the middle of the total length, and beneath 

 the second or third ray of the second dorsal, and is coterminal with that fin ; 

 its two spines are very slender. 



The caudal fin is slightly emarginated and its lobes rounded ; the median 

 rays form a ninth (11-100) of the total length; the longest nearly equal a 

 seventh (14-100) of the same. 



The pectoral fins are nearly equal in length to an eighth (13-100) of the 

 total. 



The ventral fins are inserted immediately behind the bases of the pectorals ; 

 the first and second branched rays are equally long, and exceed an eighth 

 (12-100) of the fish's length. The spine is slender and bony. 



The number and character of the rays of the respective fins are indicated in 

 the following formula : 



D. XII. I. 22. A. II. 23. C. 10, 1, 8, 7, 1, 9. P. 2, 14. V. I, 5. 



The scales are arranged in very oblique rows, the row from the first ray of 

 the second dorsal ending nearly at the base of the twelfth or thirteenth anal 

 one. The exposed parts are nearly twice as high as wide ; there are from eighty- 

 two to eighty-six along the lateral line ; between that line and the dorsal fin 

 there are seven rows. All are ctenoid. 



The color of the body and head is nearly uniform, tinged with purple above 

 the lateral line and more silvery beneath. The first dorsal fin is very minutely 

 punctulated, especially near the margin and the front of each spine. The rays 

 of the second dorsal are each banded with two or three dark bars, which en- 

 croach on the membrane in front. The margin of the caudal is lighter. The 

 pectoral and ventral fins are immaculate. 



Total length, 6.3-10ths 100 



Body Greatest height 12 



Least height - 5 



Width 9 



Head Length 23 



Length of operculum 4 



[Dec. 



