1432 Bulletin //, United States National Musc2im. 



Lateral line scarcely arched, becoming straight opposite front of soft dor- 

 sal. Color lustrous bluish gray above, silvery below; middle of sides 

 with indistinct lengthwise streaks formed by clusters of dark dots in the 

 centers of the scales ; snout and tips of lower jaw blackish ; a dark blotch 

 on opercle above; sides of head bright silvery; tins light straw-color; 

 upper half of pectorals dusky; spinous dorsal finely speckled with black; 

 upper half of axil brown; peritoneum pale; lining of opercle black above. 

 Iris bright yellow, dusky above. Length 7 inches. Panama; not uncom- 

 mon. The species has the very small anal of Odontoscion and the sjiur-like 

 preopercular spine of BairdieUa, while in its dentition it is intermediate. 

 (apxiSiov, diminutive of dpxoi, anus or anal.) 



Odontoscion archidium, JORDAN & Gilbert, Bull. U. S. Fish Comm. 1881, 317, Panama 



(Coll. C. H. Gilbert) ; Jordan & Gilbert, Bull. T. S. Fish Coram. 1882, 111. 

 BairdieUa archidium, Jordan & Eigexmann, I. c, 386, 1889. 



580. BAIRDIELLA, Gill. 



(Mademoiselles.) 



BairdieUa, Gi\.\., Cat. Fish. East Coast North America, 33, 18G1 (arc/yroleuca^chrysura) 

 Nector, Jordan & Evbemann, new subgenus {chrysoleuca). 



This genus is characterized by the oblique mouth, little cavernous 

 skull, few rows of small teeth, slender gill rakers, and the preopercle 

 armed with a plectroid spine. It is certainly a very natural group, and 

 worthy of recognition as a distinct genus, although its relationships with 

 Ophioscion and especially with StelUfer are very close. The numerous 

 species are all American, all small in size and silvery in coloration, and 

 some of them are remarkable for the great size of the second anal spine. 

 In others this spine is quite small. These variations among species 

 unquestionably closely allied show how slight is the systematic value to 

 be attached to the size of this spine. (Named for Prof. Spencer Fullerton 

 Baird, for many years United States Commissioner of Fish and Fisheries, 

 and one of the most broad-minded and successful workers in systematic 

 zoology.) 



BaIRDIELLA : 



a. Teeth of the lower J-a^v unequal, chietiy biseria! ; the inner teeth more or less enlarged ; 



preorbital narrow. 



b. Second anal spine moderate, 2^ in head, not so long as soft rays, not reaching tip 



of last ray when depressed. Color silvery, punctate ; fins yellow ; depth 3 



in length. D. X-I, 22; A. II, 10. CHRVSUHA, 1814. 



bb. Second anal spine very long, § length of head, reaching beyond tip of last ray ,- 



base of anal oblique, forming an angle with ventral outline. 



c. Mouth terminal, very oblique; second anal spine excessively large, If in 



head, longer than any soft ray. Color silvery; depth 3J. D. X-I, 23. 



ENSIFERA, 1815. 



cc. Mouth not quite terminal ; preorbital narrow, but broader than in ensifera. 



d. Dorsal rays X-I, 28; dorsal spines very slender, the highest IJ in 



head; pectorals IJ-in head; second anal spine very long, silvery, 



punctate, a dark axillary spot; dejtth 3^ in length. icistl\, 1816. 



d(l. Dorsal rays X-I, 23 ; dorsal spines stiff, lower, the highest 2 iu 



head; second anal spine If ; pectorals If. Color soiled silvery ; 



depth 3}. RONCHUS, 1817. 



