130 Annals Entomological Society of America [Vol. IX, 



Long duration of copulation, the absence of a spermatophore 

 and the superposition of the body of the male during copulation 

 divides the Phasmids and the Acrididse at once from the 

 Locustidae and the Gryllidae. Minor peculiarities in these 

 factors permit a division between the Acrididas and the Phasmids. 

 The Locustidae and the Gryllidae have a short duration of cop- 

 ulation, and a spermatophore which is usually visible. The 

 Locustidae and the Gryllid^ may be divided upon the ground 

 that there is a superposition of the body of the female in the 

 Gryllidae and an "end to end" position of the bodies in the 

 Locustidae. The mole crickets may be divided from the other 

 Gryllidae because of their peculiar modification of the usual 

 body position. 



GRYLLIDAE 



GRYLLOTALPIN^ ACRIDIDAE 

 Af \ / \PHASMIDAE 



LOCUSTIDAE 



Fig. 4. Classification based upon the development of spermatophores in- 

 those forms showing an inclination toward this structure. Acrididas and Phas- 

 midae, having sperm masses resembling spermatophores but not enclosed in a 

 membrane, are placed at one extreme. Gryllidae have definite spermatophore, 

 but highest development is reached in Locustidae, which are placed on the left 

 extreme. 



An attempt is made in Figure 5 to summarize the factors 

 that have been named as well as some additional ones. The 

 main division is made because of the following facts: The 

 Blattidae and the Mantidae have a definite egg capsule or 

 ootheca; they have no development of an external ovipositor for 

 inserting eggs into the ground or into twigs and they neither 

 produce sounds nor have organs for the reception of sounds. 

 The other groups are united because they possess ovipositors, 

 because they have organs for producing and receiving sound 

 and because they do not lay their eggs in a capsule. The posi- 

 tion of the Phasmids is doubtful but a consideration of all their 

 breeding habits will place them in the position shown, nearer to- 



