NATURAL SCIENCES OP PHILADELPHIA. 278 



Head oblong, with the snout projecting. Preoperculum unarmed. First dor- 

 sal fin above the pectorals, and sustained by eight spines ; second dorsal ob- 

 long. Anal fin elongated ; its anterior half is mostly opposite to the dorsal fin. 

 Pectoral filaments generally five and extremely elongated. 

 Type. Polynemus quinquarius. 



The genus Polynemus as now restricted is quite different from that called by 

 the same name by recent naturalists, its type not having been known to Cu- 

 vier and Valenciennes, and disagreeing in its generic characters with all the 

 species referred by them to that genus. The present has the same limits as 

 Pentanemus of Giinther, but that name cannot be preserved. 



The name of Polynemus was first introduced into Science by Gronovius, and 

 must be retained for this genus, while almost all of the species which have 

 been described by Cuvier and Valenciennes and subsequent authors as Poly- 

 nemi, should be placed in a genus called Trichidion. Gronovius has, with his 

 usual ability and accuracy, characterized the genus in his " Museum Ichthyo- 

 logicum," and has referred to Pentanemus, a manuscript name of Artedi, which 

 he has refused to adopt on account of its too exclusive character, and because it 

 does not apply to a species figured by Edwards which was supposed to belong 

 to the same genus.* Gronovius has only described one species, which is the 

 same as that known by Artedi, whose description and figure were published 

 four years afterwards in the great Thesaurus of Seba. Gronovius indeed al- 

 ludes, at the end of his description of that species, to the fish of Edwards, but 

 the genus was established more especially for the species described, and was 

 intended to supersede Artedi's unpublished name. His must be, therefore, 

 evidently retained for the species described, while Artedi's must be considered 

 as a synonyme. In no case could that of Polynemus be retained for the ma- 

 jority of the Polynematoids, for Klein had previously formed a genus to which 

 he had given the name of Trichidion, which included such species. 



Polynemus quinquarius Linn. 



Polynemus Gronovius. 



Pentanemus Artedi. 



Polynemus quinquarius Linn., Systema Naturae, vol. i. p. 521. 



Polynemus Artedii Bennett, Proc. of the Committee of the Zoological Society 



of London, vol. i. p. 146. 

 Polynemus macronemus Pel. Bijdragen tot de dierkunde, vol. i. pp. 9, 10, pi. vi. 

 Habitat. West Indian seas and the western coast of Africa. 



Group TRICHIDIONTES Gill. 



Pinna dorsalis analisque subsequales, oppositae. Preoperculum armatum. 



Dorsal and anal fins nearly equal and opposite to each other. Preopercu- 

 lum armed. 



* Ob nimis strictam CI. Artedii denominationem, nomen Pentane.mi displicet, quum sub 

 eodem Genere militnt Paradisace piscis Edward), cui septem Appendices ad Pinnas Pec- 

 toris, qui hinc inscribendus esset Heptanemus ; verum ad evitandas plures conlusiones, 

 nomine parum generaliori Polynemi nimirum, insignire non dubitavi. Nomen autem 

 compositum est ex 7roKu; and viS^n filum, utpote a parte inferiore Pinnarum Pectoralium 

 ossirula utrinque continet, qua; in aliis piscibus insolita sunt. 



t Polynemus macrophthalmus Bleaker, Acta Socictatis Indo-Nederlandica, voi. v. Ze- 



vende Bijdr. ichth. Sumatr. p. 10. 

 Habitat. Sumatra. 

 The description is unknown to me, not having yet seen the fifth volume of the Acta. 



1861.] 19 



