( 145 ) 



IX. On the Ge7icric Characters of Haivaiian Crabronidye ; 

 four neio genera characterized. By Robert Cyril 

 Layton Perkins, B.A. Communicated by Dr. 

 David Sharp, M.A., F.R.S. 



[Read March 5th, 1902.] 



When describing the species of Hawaiian Crabronidse in 

 the " Fauna Hawaiiensis " I referred the bulk of the 

 species to the subgenus Solcnius, establishing a new genus 

 Nesocrdbro for the remainder. At that time I erroneously 

 supposed the common European Grdbro vagtis to be the 

 type of Solenius, and at the same time pointed out that 

 the Hawaiian species would probably form several new 

 genera. It still appears to me that the Crabro vagus is 

 most closely allied to some of these species, but is not 

 congeneric. Three of the Hawaiian species are evidently 

 generically distinct from the others, each forming the type 

 of a new genus, and two of these appear to me to be 

 highly remarkable forms. The remaining species formerly 

 referred to Solenius are still a rather ill-assorted lot, show- 

 ing important differences in structure, but still may be 

 conveniently included in a single genus. Nesocrahro, the 

 peculiar genus previously characterized, is also a very 

 distinct form, and in the table of generic characters given 

 below it is included with the four other genera. I may 

 add that I have not been able to add a single new species 

 of Crabronidse to the Hawaiian list during my present 

 visit, and I imagine that very few species remain to be 

 discovered. All the Crabronidse of the islands belong to 

 Ashmead's subfamily Crabroninse, the other subfamilies 

 being ciuite unrepresented. Of the Hawaiian genera I 

 consider that the species of Xenocrabro probably most 

 nearly resemble the type by which the islands were 

 originally colonized, and that the other four are special 

 developments in various directions from Xenocrahro, the 

 development of generic characters having proceeded along 

 much the same lines as is the case with Crabronids in 

 other parts of the world. Thus X. afjinis makes a distinct 

 approach to the genus Nesocrabro, X. monticola to Hylc- 

 crabro in some important characters. 



TRANS. ENT. SOO. I.OND. 1902. PART II. (.JUNE) 



