23 



RECENT LITERATURE. 



Fauna Hawaiienais ; or, the ZodIoi/i/ of the iSantlwick (Hawaiian) Isles. 

 Vol. I. Hymenoptera Aculeata, pp. 1-122 ; two Plates and 

 Map. ByR. C. L. Perkins and A. Forel (March 20tli, 1899). 

 Vol. II. Orthoptera, pp. 1-30, and two Plates (August 19th, 

 1899) ; and Neuroptera, pp. 31-89, and three Plates (iSepteinber 

 25th, 1899). By R. C. L. Perkins. Edited by Dr. D. Sharp. 



Isolated in the midst of the vast North Pacific Ocean, 2850 miles 

 from San Francisco and 3500 miles from Kamtchatka — the nearest 

 continental points east and west — and separated from them by some 

 of the profoundest depths of ocean ; a little nearer to, but still far 

 away from, the coral islands and reefs of the South Pacific, connected 

 with them only by scattered islets and atolls — almost or entirely unin- 

 habited, — the Saudwich Islands, or Hawaiian group, undoubtedly form 

 to the student of the geographical distribution of animals the most in- 

 teresting country in the world. 



Chiefly through the collections made by Blackburn, some know- 

 ledge has been acquired, during the last quarter of a century, of the 

 salient characteristics of the insect fauna ; but, having regard to the 

 increasingly numerous importations into the country, a renewed 

 survey was very desirable before the extinction or further difl'erentia- 

 tion of the existing fauna took place. This has been eftected by the 

 explorations of Mr. Perkius during a period of several years, and his 

 collections are now being systematically worked out by a number of 

 zoologists. One naturally reserves a final summary of the character- 

 istics of the insect fauna till the last entomological contribution has 

 appeared ; meanwhile some notices from time to time of the various 

 parts may be interesting. 



Of Aculeate Hymenoptera one hundred and ninety-eight species 

 are recorded, though of these twenty-eight are importations, all the 

 main divisions of the group, except the ants, being well represented 

 by endemic forms. The Fossores embrace six genera and thirty-four 

 species, thirty-one of the latter being endemic. The wasps comprehend 

 two genera and eighty-eight species (eighty-six species endemic). The 

 bees comprise three genera and fifty-six species, of which fifty-two 

 species are indigenous. Of ants twenty species (belonging to twelve 

 genera) are recorded, of which only one "has any claim to be con- 

 sidered endemic." " So far as one can judge from a study of the 

 relationship of the endemic species to one another, all the Mimesidae, 

 Crabronidfe, Eumenidie, and the bees of the genus Nesoprosopis could 

 have been evolved from four species which reached the islands at some 

 very remote period, one of the four species of course representing each 

 group. The total absence of any representative of so many groups of 

 the Aculeata, certainly not less fitted to pass over the great distances 

 between the islands and other lands, and for which the country is ad- 

 mirably adapted, is a point greatly in favour of the view that the 

 numerous species of each of the families represented arose from a 

 single immigrant species, and the examination of the structures of the 

 species themselves greatly supports this view. How rarely an immi- 



