I am indebted to Dr. W. MICHAELSEN and Dr. R. HARTMEYER for 

 the opportunity of examining the very interesting collection of Blattidae 

 formed on the Hambourg expedition to S. W. Australia. All the specimens 

 are preserved in alcohol, so that study of structural details is rendered 

 more easy than is usually the case with dried specimens. The collection 

 illustrates admirably the fact that Australia is the head-quarters of the 

 apterous cockroaches belonging to the Potyzosteria-group of the subfamily 

 Blattinae, no fewer than 27 species out of a total of 41 being of this 

 section. There are only very few and scattered species of the Poly zoster ia- 

 group in extra-Australian regions, if we exclude the neotropical genera 

 Eurycotis and PelmatosUplia, which, though presenting one constant difference 

 from Polyzosteria and its allies in the greater distance apart of the eyes, are 

 nevertheless very closely allied to the Australian genera. Australia presents 

 so many evidences of the great antiquity of its fauna that I should like 

 to be able to assert with confidence that the Polyzosteriae constitute a very 

 ancient group of cockroaches, but this I cannot conscientiously do. The 

 geological evidence is directly opposed to the view that apterous Blattidae 

 are more primitive than winged forms and the method of depositing the 

 eggs in a chitiuous capsule as do all the Blattinae cannot be regarded as 

 other than a highly specialised habit; we can only say that it is probably 

 a more primitive habit than is viviparity in thisgroup of Orthoptera. It 

 is quite likely that the climatic conditions of Australia are in part responsible 

 for the large proportion of apterous species of Blattidae in that continent ; 

 without being able to explain the reason it is nevertheless the fact that in 

 desert regions or in regions where droughts are of long duration apterous 

 species of Blattidae are more numerous than winged species, w r hilst in the 

 moist jungles of West Africa and the Malay Archipelago the converse is 

 true. The collection of Drs. MICHAELSEN and HARTMEYER illustrates this 

 fact also, for of the 11 species not belonging to the apterous Polyzosteria- 

 group, only 6 possess wings capable of flight, and of these 6 species 2 are 

 importations from extra-Australian areas and 1 is winged in the male sex 

 only. 11 of the species in the collection I regard as new to science. A 

 few species are represented by immature forms only and these I have only 



Die Fauna Siidwest-Australiens. II. 



