2 BULLETIN OF THE 



observation. In 1888 the naturalists of the U.S. Fish Commission 

 steamer " Albatross " obtained considerable collections on Chatham, 

 Charles, Albemarle, Indefatigable, James, and Duncan Islands, which 

 were rej^orted on brieliy by Bruner, who specified ten species and indi- 

 cated five others. The "Albatross" again visited the islands early in 

 18D1, and collections were made by A. Agassiz on Chatham, Charles, 

 and Duncan Islands, which form the subject of a short unpublished notice 

 by Riley. Finally, later in 1891, Baur made a special trip to the Galapa- 

 gos for collecting animals and plants upon the land, under the auspices 

 of Clark University, and brought back Orthoptera from Chatham, Hood, 

 Gardner, Charles, Albemarle, Barrington, Indefotigable, Duncan, Jervis, 

 and Tower. 



All the specimens collected on these several explorations, except those 

 of Mr. Darwin, Commander Cookson, and the frigate "Eugenie," and 

 including specimens of all but one of the species reported as obtained 

 by them, have been studied by me, and form the subject of the provsent 

 paper. I owe the opportunity of studying them to the liberality of the 

 U. S. National Museum, the Museum of Comparative Zoology, Clark 

 University, and Dr. Baur. 



They come from eleven different islands of the group, but mostly 

 from Charles, Chatham, Albemarle, awd Indefatigable. There are but 

 twenty species of Orthoptera, twelve of which are found on Charles 

 Island, eleven on Chatham Island, four each on Albemarle, James, and 

 Indefatigable, while only a single one is known from each of the others. 

 Only nine of the species are known from more than one island, though 

 one is known from eight ditferent islands. Excepting the cockroaches, 

 fi^ve in nuujber and cosmopolitan forms, only two are credited with occur- 

 rence elsewhere (on the west coast of South America), and these cases 

 perhnpe require reinvestigation. The fact that the cockroaches are cos- 

 mopolitan firms and have been brought only from tlie two islands 

 (Charles and C'hatham) which have or have had settled inhabitants, 

 sufficiently shows that they have been introduced commercially. That 

 these same islands have been more frequently visited by naturalists — 

 Charles Island probably by all of them — is am])le explanation for 

 the larger number of species other than Cdckroachcs known from them. 

 The following table shows the distribution of the dilierent forms : — 



