Exoglossum. 155 



The phalaena devastator is never seen during the day ; it 

 conceals itself in the crevices of buildings, and beneath the 

 bark of trees. About sun-down it leaves its hiding-place, is 

 constantly on the wing, and very troublesome about the candles 

 in houses. It flies very rapidly, and is not easily taken. 



Such is the description of this formidable enemy to vegeta- 

 tion. No eflicacious method has yet been taken to prevent its 

 ravages, but the one who could accomplish it, would do the 

 cause of agriculture an essential service. 



Art. XIV. Description of a JVeu; Genus ofJVort'" Ameri- 

 can Fresh water Fish, Exoglossum, by C. S. Rafi- 

 NESQUE, Esti. 



BXR. LESUEUR has published, in the 6th Number of the 

 Journal of the Academy of Sciences of Philadelphia, for Sep- 

 tember, 1817, the description of a new fish, which he calls 

 Cyprinus maxillingua : he considers it as a very singular and 

 anomalous species, owing to the peculiar structure of its lobed 

 lower jaw and tongue, which is external, and situated as an 

 appendage to the former. It was discovered in Pipe-creek, 

 Maryland, in June, 1816, by said author, who confesses that 

 he does not consider it as properly belonging to the genus 

 Cyprinus^ and presumes that when other species shall be dis- 

 covered, possessing the same character, they will constitute a 

 separate genus. Although this principle and presumption is 

 correct, it was wrong to delay the formation of such a distinct 

 genus, because only a species was then known, since so many 

 genera are composed of single species. However, Mr. Le- 

 sueur's expectation was verified even before he wrote it, since 

 in May, 1817, I had discovered in the Fishkill, State of New- 

 York, another, species, evidently congenerous with the Cypri- 

 nus maxillingua, having the same structure of the mouth, &c. 

 I therefore venture to establish a separate genus for those two 

 species, having no doubt that many more will hereafter be 

 added to it by accurate observers, and I give to it the name of 



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