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Show 1867.] MR. G. R. CROTCH ON AZOREAN COLEOPTERA. 365 unchanged; the Homalium and Phlceophagus are the only two "autochthones." Their connexion with the Canaries is very slight and little marked, 114 species only being common to the two groups. Of these- (1) Ninety-seven are, as before, universal. (2) Seven are common also to Europe; and four of them, at least, are introduced. Hydroporus planus. Anthicus humilis. Gyrinus dejeani. Ocypus olens. Dermestes frischii. Homalota nigra. Trachyscelis aphodioides. (3) Eight are, as before, common to Madeira. (4) Two only remain as peculiar to the Canaries and A-Vzores ; and of these one (Anobium villosum) is a mere introduction; but the other (Calosoma azoricum) is a very singular insect, representing the G. maderee of Madeira, and extending even to the Cape de Verde Islands. The Canaries are remarkable for possessing both forms, though in separate islands. With the little uninhabited rocks called the Salvages, the Azores have two species in common (Harpalus rotundicollis and Phaleria bimaculata), both occurring in some abundance. But the most remarkable portion of the Azorean fauna remains yet to be noticed, viz. those species which it has in common with America. These are- AHolus melliculus. Tceniotes scalaris. Monocrepidius qwslicus. The Heteroderes azoricus also is probably a mere modification of an American species, which has succeeded in establishing itself here. The Tceniotes also appears thoroughly naturalized. Whether these species owe their introduction to colonization and human intercourse or to natural means must remain an open question. For the former much is to be said. An open and continual communication exists between S. Miguel and Bahia; and Mr. Godman informs me that very large quantities of plants and trees are imported to form gardens. This latter fact may account for the numerous European species also. On the other hand, the occurrence of Clytus erythrocephalus on the desolate rocks of the Salvages, where it could not have been introduced, suggests that, after all, the Gulf Stream may have been the origin of these peculiar species. This is borne out by the fact that they are all wood-feeding species, so that they would readily come in logs in the pupa state without injury; and by the fact that the ILet. azoricus must have been introduced at a period previous to the Portuguese colonization to account for its abundance in several islands and its modified characters. Some light may be thrown on this also by the occurrence of Cynthia hunt era in the Canaries. Further, an African connexion is suggested by the Staphylinus hesperus (a close ally of a Cape species), and by the very remarkable |