NO. 1687. THE THORAX OF INSECTS— SNODGRASS. 561 



4. Meso- and metaplcunim (82) alike. One preparateruni (P) 

 jn-eseiit in each forming large lobe of episternnni. Epimerum fused 

 above with pseudonotimi (/W). 



VII. HKMII'TKRA. 



Species studied. — BenacKS ludde/nanam (83, 84, 85, 80, 87, 88, 81), 

 wing bases 190, 191), Ainorgius ameriecuiuni, Belostotnidd'. 



Chanictcristics. — The following characteristics may not be general 

 to the Ilemiptera, for there evidently exist numerous structural mod- 

 ifications within the order. The drawings of Benacus haldemanum 

 can not serve as more than a basis for a comparative stud}'', but they 

 illustrate the agreement of the Hemipteran thorax with the funda- 

 mental plan of that in other insects. 



1. ]Microthoracic plates absent. 



2. Trochantins {Tn) present in each segment, but hidden, together 

 with bases of coxae, by the produced edges of the pleurites (83, 85). 



o. Anterior coxae articulated to condyls carried by pronotnni 



■1. Posterior coxae articulated to a condyle of the metaepimerum 

 (84, 89, /t), which is inserted between the coxa and the true pleural 

 coxal process {CxP). 



5. Preparaptera not distinct from episterniim (85, 89). No post- 

 paraptera. 



G. Episternum of metathorax divided into an upper and a lower 

 sclerite (89, Eps, Eps). 



T. Scutellum of mesonotuni forms a large triangle between bases of 

 fore wings. Mesopeudonotum absent. 



8. Metanotum distinctly divided into three transverse parts by 

 transverse lines (87, /^-sr, sct^ scl). A pseudonotum (87, 88, PN) pres- 

 ent, very narrow mesially, expanded laterally where fused with 

 epimera {Epm). 



9. First abdominal tergum (87, 88, IT) a narrow bar fused with 

 metapseudonotum, expanded laterally, bearing the spiracles (I Sp) 

 and phragmal arms (I Ph). 



10. Wing bases shown by 190 and 191. G^ Sc, and E form large 

 detached sclerite at humeral angle of hind wing (191) though not 

 detached in fore wing (190). Third axilhuy divided and of unusual 

 shape in fore wing (190, 3 Ax), simple in hind wing. 



VIII. KVPLEXOl'TEKA. 



Species studied. — Sponf/ipliora apicidentatu (90-94, 98, 100), S. 

 h)'u?ineipen)us (96) . 



Characteristics. — This order has been specially studied b}^ Verhoeff 

 (1902, 1903a). The present writer has elsewliere (1908) made a com- 

 parison of the Euplexopteran thorax with that of Orthoptera and 

 Proc,N.M.vol.xxxvi— 09 .36 



