2 FAUNA HAWAIIENSIS 



Crabro, will themselves ultimately form one or more peculiar genera, the species 

 being closely related to one another, and also to the endemic genus Nesocrabro. 



Putting together the results of this analysis it will be seen that the foreign element 

 includes 3 species of two genera, representing two sub-families, two of the species 

 and both genera being known from elsewhere, while the third species has only been 

 taken in the city of Honolulu, a fact which alone would mark it as foreign. This 

 gives an average of i '5 species to the genus. The endemic species also represent 

 two sub-families, with four genera, and 31 species. Three of the genera are endemic 

 and all of the species, and there is an average of 775 species to a genus. 



ii. In the true Wasps, or Diploptera, the Vespidae have two species of Polistes, 

 both foreign forms, and known to have arrived since the settlement of white men 

 on the islands. There is no doubt that both were introduced by man, and it is 

 remarkable that a parasitic Stylops should have been brought with them. 



The Eumenidae are represented by the single genus Odyneriis, which is extremely 

 rich in species, no less than 86 distinct species having occurred. All the species are 

 endemic and form a most remarkable assemblage, exhibiting a great variety of form, 

 although all belong to one section of the genus. Some of the species might readily be 

 separated as distinct genera, were this course advisable, so great are their peculiarities, 

 but as this would still leave the bulk of the species in Odynertis, and dissociate what 

 appears to be really a natural series, it seems better to leave them intact, until they can 

 be separated as a whole. 



iii. In the Anthophik, or Bees, the Obtusilingues have 52 species all belonging 

 to one genus, which, so far as is known, is endemic. These again form a remarkable 

 series, and some of the species at first sight would hardly be recognized as belonging 

 to the section to which they are assigned. Nevertheless when studied as a whole 

 they are seen to be intimately related to one another, widely different as the extreme 

 forms of the series may appear. 



The Acutilingues are very poorly represented by a single Xylocopa, known to 

 have been imported, and three species of Megachile, two of which are recent introduc- 

 tions, although not identified from elsewhere. They have greatly increased in numbers, 

 and extended their range over the islands during the last few years. The third species 

 is very possibly endemic, and is probably becoming scarcer, being now a rare insect, 

 or at least excessively local. 



Thus of the Fossores, Bees, and Wasps together, there are 170 endemic species 

 in 7 genera, four of the latter being also endemic, with an average of over 24 species 

 to a genus, while there are 8 introduced species representing 5 genera, giving an 

 average of less than two species per genus. 



The arrival of Megachile in the islands, presuming that M. diligens is really an 

 endemic species, was no doubt very recent, compared with the remote periods at 

 which the first representatives of the Fossores, Odyneri and the blunt-tongued Bees 



