1886.] MR. BOURNE ON THE FAUNA OF DIEGO GARCIA. 333 



Gannets and Frigate-birds breed at the southern end of the island ; 

 and although they are well known to be enemies on the wing, the 

 Frigate-bird pursuing the Gannets and compelling them to disgorge 

 the fish they have caught, yet they nest close together without 

 molesting one another. The Gannets were hatching out on my 

 arrival, but the Frigate-birds did not breed during my stay. The 

 snow-white Tern, Gygis Candida, breeds in considerable numbers ; 

 the peculiar situation in which this bird lays its egg has been de- 

 scribed by Mr. Forbes in his recent work ('Wanderings of a 

 Naturalist in the Malay Archipelago '), and I have nothing to add 

 to his account. Although Whimbrels, small Plovers, Herons, and 

 Sandpipers are numerous on the island, they do not appear to breed 

 tliere. I was assured by the negroes that their eggs were never 

 found ; and M. Spurs, a former resident on the island and a natura- 

 list of no mean order, tried during a stay of fifteen years to obtain 

 the eggs or young of these birds, but without success. 



Tliere are no indigenous Mammalia or Amphibia. A species of 

 Gecko (Plaiy(lactylusmauritanicusl)h common, and a Mud-Tortoise 

 is abundant in some of the marshy pools. The former of these 

 reptiles has probably come across in ships from Mauritius ; but I 

 cannot account for the presence of the latter, which is unlikely to 

 have been brought over as a pet, for it is abundantly provided witii 

 stink-glands and emits a most unpleasant odour ; it cannot have 

 been brought over to serve any useful purpose, nor is it likely to 

 have been accidentally imported. Yet, unless it was brought over 

 by man, it is difficult to imagine how this animal can have found 

 its way over the sea to so distant a spot as Diego Garcia. The 

 insect life is not varied ; huge cockroaches, mosquitoes, flies, and 

 ants swarm everywhere and are a great pest. I found a few nests 

 of Termites or White Ants in decayed cocoa-nut stems, but they 

 are rare. Of Orthoptera there are two species of Locusta, one of 

 Acridium, a Forjicula, and a Gryllotalpa, Of Lepidoptera I found 

 three species of Nocturnal and one of Diurnal JNloths, and I noticed 

 a few individuals of Vanessa bolini, and one individual of CEnone. 

 Three species of ^schna were abundant in the marshes. Of 

 Coleoptera I only found four species. Of Myriapods I found a 

 Scolopendra, a luujinous species of Geophihis, and an lulus. 



The most remarkable inhabitants of the land are the Crabs. 

 Hundreds of Land-Crabs of the genus Gecarcinus are to be found 

 in any part of the island, and are a great annoyance to the inhabi- 

 tants, for they do great destruction in gardens, and prevent the 

 cultivation of the potato or vegetables. There are several species 

 of these crabs, one of which attains to a large size and gives 

 a formidable nip with its large claws ; it is so conscious of its power 

 that it attacks any person who is walking through the grass in 

 which it lurks, and is able to give the naked foot of a negro a 

 severe wound. Large Hermit-Crabs of the genus Ccenohita are 

 found, some of them hiding their abdomens in broken cocoa-nut 

 shells in lieu of the shells of mollusks, there being but few of the 

 latter that are large enough. The close relative of these Coenobitcr, 



