1 84 FAUNA HAWAIIENSIS 



structure of the prothorax in these Insects to which considerable importance was 

 attached by Dr Leconte, who regarded Proterkinns as belonging to the Rhynchophora 

 and Aglycyderes as related to the Colydiidae (see quotation from a letter, Trans. Ent. 

 Soc. Lond. 1879, Pt. I. p. 78), it may be noticed that the differentiation between the 

 dorsal surface and flanks is much more marked in a few species than in the majority of 

 P7'oter]mms, which, as Sharp (/. c. p. 80) has remarked, is also the case with the two 

 species of Aglycyderes, the New Zealand species having the differentiation between the 

 parts of the prothorax less definite than the Canarian species. 



The characters which I have found most useful in the separation of the species are 

 the nature of the clothing, the size and form of the eyes and of the lobes of the front 

 tarsi, the condition of the humeral angles of the elytra, the shape of the prothorax, the 

 length of the antennal joints, and the development of the club (or 3 apical joints), and 

 the puncturation of the abdomen beneath. In few species are any of the characters 

 constant, when a long series of examples are examined, the size of the individuals being 

 extremely variable, and these depauperated examples often have the structures charac- 

 teristic of the species much modified. For these reasons I have not found it easy to 

 identify the numerous species hitherto described, although through the kindness of 

 Dr Sharp I have been able to carefully examine the types of all the species described 

 by him. The description of most of these species was drawn up from only one or two 

 examples, and except in the case of a few of the most distinct species, such material is 

 quite inadequate for an accurate knowledge of the species. In several cases when 

 I have referred a species taken by myself to one already described by Dr Sharp, I have 

 not been able exactly to match the types with any individual even in a series of 

 specimens, and it is probable that this is due to the specimens having been captured in 

 a slightly different locality to that whence the typical examples came, but it is of course 

 possible that some of the species have themselves undergone slight changes during the 

 last quarter of a century. 



Of the 122 species known 8 only appear to extend their range beyond a single 

 island, and in few, if any, of these do the examples from different islands altogether 

 agree, while several of these species inhabit only two of the closely adjoining inter- 

 mediate islands of the group. Of the species that restrict their range to a single island 

 Kauai has 29, Oahu 28, Maui 27, Lanai 9, Molokai 9, and Hawaii 12. To facilitate 

 the discrimination of the species I have arranged the species in seven divisions, one for 

 each island and comprising the species peculiar to it, the seventh containing the few 

 species which are found on more than one island. 



Nearly all the species are attached to the dead or dying wood of the forest trees, 

 and the individuals frequently congregate in small batches beneath the bark, in which 

 the larvae feed, and they are very sluggish in their habits. Several are found in the 

 stems of tree-ferns, and one or two are attached to smaller ferns {Pteris etc.), while a 

 few live on small shrubs and woody creepers. 



