PROTOPERLARIA 



81 



defined by JMartynov appear to be an unnatural assemblage of 

 diverse forms, including, for example, the Delopterida?, which are 

 relegated by Tillyard to the Psocoptera. In 1928, Tillyard, 

 from a study of abundant Kansas material, showed that 

 Letmnatophora and its allies, which were referred by Sellards 

 to the Protorthoptera, exhibit relationships with the recent 

 order Plecoptera, and proposed the new order Protoperlaria for 

 their inclusion. Members of this order agree with the most 

 primitive living Plecoptera in their general facies, including the 

 presence of cerci and the absence of a 

 median caudal prolongation, in the 

 general shape of the wings and the 

 possession of a large fan-like anal 

 area to the hind pair, and in the 

 partial fusion in the hind wings of Rs 

 and MA. The well-developed anal 

 lobe and the absence of an irregular 

 network of obliquely arranged veinlets 

 easily separate this order from the 

 Palaeodictyoptera. 



The discovery by Carpenter (1935) 

 of nymphs belonging to the Proto- 

 perlaria is of great interest. They 

 possessed nine pairs of lateral 

 abdominal gills which still remain as 



vestiges seen in the imagines (Fig. 42). Fig. 42. Nymph of Proto- 

 T ., p . ^1 11 perlaria. (After Carpenter.) 



In these leatures they are closely 



paralleled by the Eustheniidye, which form the most primitive 



family of living Plecoptera. 



The order comprises only the single family Lemmatophoridce, 

 which includes the following genera : Lenwiatophora Sell., 

 Paraphrisca Handl., Leconium Sell., Artinska Sell., and Sellardsia 

 Till., along with certain forms from North Russia (Martynov, 

 1928a). 



Protohemiptera Handl. The existence of this order is based 

 upon well-i^reserved but fragmentary remains of two genera, 

 probably belonging to separate families, viz., Eugereon Dohrn. 



