ABSTRACT 



Filefishes of the western North Atlantic, important forage fish because of 

 their abundance, have been inadequately described and are difficult to identify 

 to species. In determining the species that occur in the western North Atlantic, 

 several thousands of young and adult specimens were examined, and four genera 

 and nine species were found to be valid and separable by external characters: 

 Alulera monoceros, A. scripta, A. schoepfii, A.heudelotii, Monacanthus ciliatus, M. 

 tuckeri, Stephanolepis hispidus, S. setifer, and Amanses pullus. 



Considerable intraspecific variation in profile was found, resulting in the 

 synonymizing of several species, among them Alulera punctata and Stephanolepis 

 spilonotus. 



Evidence is presented for the use of Monacanthidae as the family name, 

 rather than Aluteridae. 



Keys to juvenile and adult specimens are presented, and proportional meas- 

 urements and fin-ray counts are given in tabular form. Graphs, charts, photo- 

 graphs, and drawings supplement the data to facilitate identification. 



Information on ranges and behavior is also presented. 



IV 



