326 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii. 



from a letter from Dr. Christopher Aurivillius, of the Stockholm 

 Museum, the incorrectuess of this title-page, and proves without the 

 shadow of a doubt the priority in publication of Dr. Mayr's work. 



The group was called by Thomson a tribe — Encyrtina — and he divided 

 it into three sections, based principally upon mandibular characters, 

 besides giving an excellent table for distinguishiug the genera. Eight 

 new genera and 26 new species were described. Three of these genera 

 are, however, synonyms: Liocarus equals Prionomastix Mayr; Wob- 

 rimus equals Homalotylus Mayrj while Trechnites equals Metallort 

 Walker. 



Thomson designates as the type of JEncyrtus, E. scutellaris Dalman, 

 a species evidently synonymous with Encyrtus {Chrysis) infidus Eossi. 



The work of Thomson is unquestionably of great value, and he has 

 drawn attention to several important structural characters not pre- 

 viously or subsequently noticed. In my own work I have made use of 

 some of these characters, one of which — the shape and dentition of the 

 mandibles — although not easily seen, I consider of tribal value. 



In 1888 Christopher Aurivillius discovered and described his genus 

 Arrhenophagus, a remarkable form in the group. 



A year later, 1889, De Stefani, an Italian, established his genus 

 HoplopsiSy a genus still unknown to me in nature, but which, judging 

 from the description, does not belong to this subfamily, but to the sub- 

 family Eupelmime, '•'■ Thorax foveolatus^'' being a character found only 

 in the Eui^elminie. 



In the United States until within comparatively recent years very 

 little original work was done in the family. 



The first American who described a species in the group was Thomas 

 Say, whose iSerlion ter^ninalis, described in 1828 and placed by Cresson 

 in the genus Scelio, in the family Proctotrypidse, is an encyrtine 

 belonging to Mayr's genus Homalotylus. 



It has been since redescribed twice : Once by Dr. Shimer as Eutelus 

 scymnw, and again by Dr. Howard as Homalotylus ohscvrus. 



Since Say's time, besides myself, the only one in this country who 

 has given special attention to these insects is Dr. L. O. Howard, whose 

 valuable contributions toward elucidating the habits, genera, and spe- 

 cies of this difficult group, found in America, are known to all working 

 entomologists. He has characterized many new genera and many new 

 species — many beautifully figured — and it is through his kindness and 

 liberality in placing at my disposal all his material in the group that I 

 am able to incorporate all of these genera in my tables. 



I desire here also to express my thanks and obligations to the well- 

 known hymeuopterologist, Dr. Gustav Mayr, of Vienna, Austria, the 

 leading Etiropean authority on the group, for sending me during our 

 correspondence, extending over an interval of nearly twenty years, 

 specimens of most of the European genera. 



With these preliminary remarks I shall now proceed with the classi- 

 fication of the group. 



