94 FAUNA HAWAIIENSIS 



Distribution. Turning our attention to distribution, we note that the Coleoptera 

 Phytophaga of the world consist of three great famihes : Chrysomehdae, Bruchidae, and 

 Cerambycidae. 



(i) Chrysomehdae. There are about 18,000 species of Chrysomehdae known, 

 they are found nearly everywhere except in the Hawaiian Islands, where there is only a 

 single species ; and even this has apparently been introduced quite recently. Chry- 

 somehdae live on foliage, and the Hawaiian Islands are doubtless well adapted to sustain 

 them, so that the absence of this great family has an important significance. 



(2) Bruchidae. A family of about 700 species, of very little importance in this 

 connection. The species live in seeds and are carried about by commerce. A few 

 specimens have been found at Honolulu. 



(3) Cerambycidae. One of the important families of Coleoptera, consisting of 

 upwards of 12,000 species. Fifty-four have been discovered in the Hawaiian 

 Archipelago, of which number forty-five are precinctive, while nine have been found 

 elsewhere. These nine species belong to as many different genera ; the individuals do 

 not differ in the islands to any appreciable extent from those found elsewhere. Owing 

 to their comparative lack of interest they have however been but little collected. There 

 is nothing in their distribution that throws any light on the origin of the Hawaiian 

 fauna. The forty-five precinctive species of Cerambycidae belong to two very distinct 

 categories. First there are single species of two genera of Prionini. Each of the 

 genera to which they belong has a wide distribution ; the Hawaiian forms are not 

 closely allied to any of the external forms ; they are in fact rather more distinct than is 

 usual in their genera, so that there is no indication of special affinity with species of any 

 other locality. The forty-three precinctive species of Cerambycini are totally 

 different from the two Prionini we have discussed : they belong to three genera, very 

 closely allied inter se, and form a special group or tribe — Plagithmysides — peculiar 

 to the islands, distinguished by the wings having no transverse fold. They seem to be 

 nearest allied to the genera Neoclytus and Euryscelis, which are found in North and 

 Central America and the Greater Antilles. They are in appearance the most remarkable 

 of the Hawaiian Coleoptera and must be considered as a very highly specialised 

 group of Cerambycidae. They are remarkable in their habits'. 



Thus there is a very great distinction between these Plagithmysides and the 

 non-precinctive Cerambycidae found in the islands ; but the two endemic Prionini 

 occupy as it were an intermediate place in their characters. These latter may be 

 compared with the Corvus hawaiiensis amongst the birds, while the Plagithmysides 

 appear to be analogous with the Drepanidae. 



' See on this point Perkins, Ent. Mag. xxxii. p. 190, and P. Cambridge Phil. See. ix. p. 373. 



