128 Annals Entomological Society of America [Vol. IX, 



wiU have the largest representation. It is possible that condi- 

 tions have arisen in Europe that have been temporarily very 

 favorable to the type of specialization of the Locustidae, causing 

 them to attain to greater diversity than the Acrididae in that 

 region or the Locustidae in America. 



The Phasmids and the Mantids have their greatest develop- 

 ment in the tropics. Consequently they are poorly represented 

 in the more generalized temperate climates of Europe and of the 

 United States. 



AN ATTEMPT TO CLASSIFY THE ORTHOPTERA ACCORDING TO THEIR 

 REPRODUCTIVE BEHAVIOUR. 



Figures 2, 3 and 4 are schemes based upon one or two factors 

 of reproduction while Figure 5 represents a classification based 

 upon all the factors collectively. 



\ACRIDIDAE MANTIOAE 



PHASMIDAE 1 BLATTIDAE 



*FiG. 2. Classifioation based upon specialization of the ovipositor, Rudi- 

 mentary ovipositor in Blattidae and Mantidae, intermediate development in 

 Phasmidae and Acrididae, maximum development in Gryllidse and Locustidae. 



In Figure 2 the classification is based upon the amount and 

 direction of specialization of the ovipositor. The first division 

 separates the Mantids and the Cockroaches from the others 

 because of the lack of an external ovipositor. In both forms the 

 ovipositor is relatively undeveloped. The Phasmids are 

 included with the Acrididae, the GryUidae and the Locustidae 

 because they have a fairly well developed ovipositor although it 

 apparently is not used. The Acrididae are separated from the 

 Locustid^ and the Gryllidas because of their relatively short 

 and undeveloped ovipositor. The Locustidae and the Gryllidag 

 as a whole have highly specialized ovipositors although some 

 have suffered an almost complete loss of the organ due to their 

 change of life. Reading from right to left we have a more or 



*In Figs. 2, 3, 4 and 5 direction and extremes of factors used in classification 

 are indicated in horizontal plane. 



