310 Mr. R. Shelford's Studies of the Blattidae. 



in the discoidal pronotum. Third autennal joint nearly three times 

 longer than the second. 



Type of the genus — P. rohusta, Shelf. 

 P. Tobusta, Shelf. 



Paramethand rohusta, Shelford, I. c, p. 31, PL II, fig. 7 

 (1907). 

 German East Afeica, Lower Meru (Stockholm Mus., 

 type ; Oxford Mus.). 



XL Revision of the genus Gpm, Br., with a descrip- 

 tion OF A NEW GENUS. 



The genus G>/na was formed in 1865 (Brunner, Nouv. 

 Syst. Blatt., p. 206) for the reception of some species 

 of African Blattidae that previously had been placed in 

 Panchlora; since that date a number of species have been 

 added by various authors, and as many of the species 

 are closely allied, cryptically coloured forms, presenting 

 few salient features of taxonomic importance, their identi- 

 fication has been attended with considerable difficulty. 

 Fortunately I have been able to examine and compare 

 nearly all the types, and ray grateful thanks are due to 

 Dr. H. Dohrn of Stettin, Dr. Y. Sjostedt of Stockholm, 

 Dr. F. Romer of Frankfort-a-M., Dr. K. Holdhaus of 

 Vienna, Dr. Giglio-Tos of Cagliari and Dr. M. Bedot of 

 Geneva for the loan of the valuable specimens in their 

 charge ; without this friendly co-operation a satisfactory 

 revision of the genus was out of the question. I have 

 received for determination large collections of African 

 Blattidae from various continental Museums, and as all — 

 but especially the West African collections — are very rich 

 ill examples of this particular genus I am confident that I 

 have in my possession at present a greater amount of 

 material for the revision of the genus than has ever 

 before been gathered together. The tropics of West 

 Africa may be regarded as the head-quarters of the 

 genus, for no less than 18 out of the 28 known species 

 occur there ; there are 4 East African and only 2 South 

 African species. In my account of the Blattidae collected 

 by Dr. Y. Sjostedt on his Kilimandjaro-Meru expedition 

 1 gave my reasons for believing that the genera Tricho- 

 mera, Kirby, and Aijotrogia, Kirby, were based on larval 

 forms of Gyna and I still see no reason to modify that 



