198 U.S. NATIONAL MUSEUM BULLETIN 202 Vol. 2 



length of head 1,7 to 1.9; interorbital space 4.2 to 4.4; longest pectoral 

 ray 1.6 to 1.7; least depth of body 2.1 to 2.4; all in length of head. 

 Distance between anterior and posterior nasal openings 6 to 7 in 

 snout. Eye 1.9 to 2.1 in interorbital space. 



Dorsal profile of head convex, forming an angle of 80 to 85 degrees 

 with ventral contour of head; pectoral fin reaches opposite ninth or 

 tenth lateral line scale; pelvics reach half way to three-fourths the 

 way to anus; distal edge of caudal fin double concave, the median 

 rays convex, or concave, with outer rays elongate on large adults. 



Color in alcohol. — Background coloration Hght brownish or olive 

 with a dusky or brownish band (reddish when alive) on back; sides 

 with two pale or whitish bands (reddish when alive). The dorsal 

 one extends from just above pectoral fin base posteriorly to caudal 

 peduncle, where it lies just above lateral fine; the lower one extends 

 from ventral edge of pectoral fin base to lower side of caudal peduncle ; 

 the two dorsal streaks are connected by pale or dusky narrow streaks ; 

 a characteristic pale band extends from rear of orbit obliquely down- 

 ward across operculum, forldng posteriorly and thence continuing on 

 breast under pectoral fin base as a band; dorsal edge of pectoral base 

 blackish, mostly on posterior side; dorsal edge of pectoral fin dusky; 

 both dorsal and anal fins have a pale streak basally, whereas the distal 

 half of these fins is light dusky or greenish; the smallest specimen 

 listed has a dusky or greenish streak in middle of dorsal and anal 

 fins and basally and distally the fins are pale or whitish (red when 

 alive); caudal, pectoral, and pelvics pale. 



Color when alive. — Background coloration bright green, pale bands 

 on sides red, dorsal pale or dusky band purplish red; pale streaks 

 on head reddish, rest of head bright green, lips green; front of snout 

 reddish with a green streak across snout just above lips; basal pale 

 streak on dorsal and anal fins red, rest of fin green; pectoral pelvics 

 and caudal fins green; the dorsal and ventral red or orange bands 

 on body continue on caudal fin just inside the greenish outer edges; 

 eye pinkish. 



Remarks. — This species is represented by specimens of moderate 

 size but no small ones were found as is usual in collecting fishes. Be- 

 cause of this, authors have tried to identify T. purpureum with other 

 related species. 



I have compared T. purpureum between the standard lengths of 

 190 to 246 mm. with a series of T. trUobata (Lacep^de) between 108 

 and 225 mm., and with a series of T. umhrosiygma between 14 and 

 275 mm., I find no overlapping of the details of the color pattern. 



