32 Annals Entomological Society of America [Vol. XV, 



internal structure. As in many Orthoptera, such as Gryllus, 

 Nemobius and Ceuthophiliis, the posterior, more exposed part 

 is more heavily chitinized than the anterior, concealed portion. 

 The lateral chitinized margins are also exposed towards their 

 bases and represent the rami (cf. Nemobins), while the long, 

 slender, internal processes are the endapophyses. The floor of 

 the dorsal sac represents, of course, the roof of the penis. There 

 appear to be no traces of parameres. 



On the whole the gentialia of Ripipteryx appear to approach 

 those of Ceuthophilus more than any other of the types studied, 

 though the pseudosternite recalls that of Nemobius to some 

 extent. The simple dilatation representing the spermatophore 

 sac suggests that of Ceuthophilus, or other Tettigoniids, and 

 the deep pocket between the pseudosternite and the penis roof 

 is also suggestive of this genus. Both of these are primitive 

 characters. The long horizontal endapophyses, on the other 

 hand, are more like those of the Acrididas, though the resem- 

 blance may be quite superficial. The striking similarity between 

 the female genitalia of Ripipteryx and the Acrididas is certainly 

 not paralleled by the male genitalia. 



AcRiDOiDEA. In the family Acrididee the genitalia are 

 remarkable for: (1) the great development of the muscles and 

 the chitinous parts which serve for their attachment; (2) the 

 upright or sub vertical position of the terminal part of the 

 penis and parameres, correlated with the upcurved, cup-like 

 form of the ninth sternum; (3) the small size of the outlet of 

 the penis; (4) the deeply retracted bases of the parameres 

 (endoparameres) , in the form of heavily chitinized wing-like 

 expansions, and the vestigial spermatophore sac, of which 

 they form the lateral w^alls; (5) the anterior position and 

 complex form of the pseudosternite; (G) the large and strongly 

 chitinized endapophyses, connected dorsally but separated 

 from the pseudosternite; (7) the absence of the glandular 

 pouches of the ejaculatory duct; and (8) the deep pocket 

 between the penis and the floor of the genital cavity. 



To illustrate the genitalia of this family we can take the 

 common Black-winged Grasshopper or Carolina Locust (Dis- 

 sosteira Carolina L.) (PI. VI, Figs. 51-54). In order to expose 

 the penis it is necessary to remove the pallium or fold of 

 integument covering the genital cavity behind the paraprocts. 

 The terminal part of the penis is now seen near the posterior 



