126 U-S. NATIONAL MUSEUM BULLETIN 2 02 Vol. 2 



length of head 2.0; fleshy interorbital space 3.5 to 4.3; longest pectoral 

 ray 1.4 to 1.7; least depth of body 2.2 to 2.4; all in length of head. 



Dorsal profile of snout forming an angle of 75 to 85 degrees with 

 ventral contour of head; pectoral fin reaches to opposite 13th lateral 

 line pore ; first and second outer rays of pelvics longest, not reaching 

 past anal origin ; distal margin of caudal fin rounded in young, truncate 

 in adults; dorsal spines all pungent. 



Color in alcohol. — Background brownish, with a wedge-shaped 

 white bar from area behind pelvic bases dorsally to lateral line; dorsal 

 part of caudal peduncle pale; pectoral base blackish or dark brown. 

 In the young there are three whitish bars across body, and the dorsal 

 and anal fins are barred with dusky; pelvics dusky basally. 



Genus PTERAGOGUS Peters 



Pteragogus Peters, Arch. Naturg. vol. 21, p. 261, 1855 (type species, Cossyphus 



opercularis Peters). 

 Duymaeria Bleeker, Act. Soc. Indo-N6erl., vol. 1, p. 52, 1856 (type species, 



Crenilabrus aurigarius Richardson, designated by Jordan and Snyder, Proc. 



U. S. Nat. Mus., vol. 24, p. 623, 1902). 

 Labrastrum Guichenot, Rev. Mag. Zool., ser. 2, vol. 12, p. 152, 1860 (type 



species, Ctenolabrus flogellifer Cuvier and Valenciennes). 



This genus may be recognized by the following characters : Branched 

 caudal fin ra3^s 5 + 5; lateral line continuous, pores 15 or 16+2 + 6 or 

 7, with 2 scales above lateral line to base of first soft dorsal ray and 

 6 scales below to anal origin ; about 23 or 24 vertical scale rows to base 

 of caudal fin ; dorsal rays IX to XI,9 to 12; anal 111,8 to 10; pectoral 

 i or ii,10 to 12; 2 rows of scales below eye on cheek and 1 row on 

 interoperculum ; a row of elongate scales on basal part of dorsal and 

 anal fins; opercle scaled; jaws equal, upper and lower jaws each with 

 2 pairs of enlarged canines, posterior pair hooked a little outward 

 and backward ; usually 1 to 4 canines at rear of toothed part of upper 

 jaw, these canines lacking on juveniles; sides of jaws with a uniserial 

 row of conical teeth; gill membranes free from isthmus, with a broad 

 fold across it; posterior edge of preopercle finely toothed, the edge 

 free posteriori}^ as much as ventrally; caudal fin rounded. 



The distinguishing of species referable to this genus is difficult 

 and uncertain because of sexual dimorphism and change in color 

 pattern from juvenile to adult. Counts of fin rays, pores in lateral 

 line, and measurements did not indicate differences of sufficient 

 magnitude to permit more than 4 species to be recognized. All four 

 species when adult, have from 1 to 4 canines at the corner of the 

 mouth on the upper jaw, but these are absent in the young. 



A study of the number of dentae on the preopercular edge, table 

 90, indicates clearly that for P. flagellifera the dentae increase in 

 number with increase in size. Thus one must conclude that the 



