THE CANADIAN ENTOMOLOGIST. 349 



3. A. rugifrons m : 



(Thomson, 1878, pp. 158-160.) 

 Eight years later, Howard (1886), in a paper entitled " A Generic 

 Synopsis of the Hymenopterous Family Chalcididje," repeated almost 

 entire, with the exception of two or three sentences of minor importance, 

 the Conspectus subgetiennn of Thomson given in foregoing, and indicated 

 that the then subgenus was as yet unknown in the continent of North 

 America, north of Mexico. Howard, however, raised the tribes of Thom- 

 son to the rank of subfamilies, and his subtribes to the rank of tribes. In 

 the following year, Cresson (1887) gave Howard's synopsis of the genus 

 Pteromalus verbatim, so up to that epoch Arthrolyius was still retained 

 as a subgenus. 



In describing the first North American species Ashmead (1893) 

 treated the group as a genus, and thus in 1893 it first attained to that 

 rank, already forshadowed by its treatment as such by Moller (1882) 

 eleven years previou^^ly and the attitude taken by Howard in regard to 

 the larger groups of Thomson. De Dalla Torre (1898) listed the species 

 of the genus, and gave Ptero7naliis Thomson {sic) as its synonym, 

 whereas in reality Arthrolytus being a part of Pteiomalus Swederus has 

 no synonym strictly, since it was taken out of the latter group and made 

 independent of it. Its synonymy^ therefore, should have been given as 

 Fteromalus Swederus (partifn). Pteromalus Thomson was a subgenus of 

 Pteromalus Swederus ; at present, the latter, therefore, should be Ptero- 

 mahis Swederus (Thomson) ; Thomson practically gave us the modern 

 conception of the genus Pteromalus. Then Ashmead (1904) in his 

 monumental work on the Chalcidoidea formally defined the genus 

 Arthrolytus in a synopsis of the modern tribe Pteromalini Ashmead, 1904, 

 which is practically the old genus Pteromalus Swederus raised to the rank 

 of a tribe. Also, Ashmead there, and previously in 1893, formally 

 designated Arthrolytus punctatus Thomson as type of the genus, formerly 

 such by page precedence. Finally, Schmiedeknecht (1907, 1909) treated 

 the genus in a manner essentially similar to Ashmead's treatment, so that 

 it is unnecessary to quote here. 



The following description of the genus is based on Thomson's 

 descriptions of the genus and species, that of Ashmead's and Moller's 



