NO. 1687. 77//; 77/OZ2.LY O/' /.VaS7;('7VS'— N.VOi>0'72.1-S8'. 539 



the fusion of the base of the parapteruin with tlic front of the epi- 

 sternuni. The same thing occurs less conspicuously in several 

 other orders. In the Neuroptera, Corydalis cornuta (147) has the 

 single preparapteruni (/^) fused with the upper end of the epi- 

 sternum {Ejm), thus giving the appearance of there being two wing 

 processes. The same thing is true of the Trichoptera as shown by 

 Ncuronia ocelli fern (l-tO, 148). Even in the Lepidoptera the parap- 

 terum (/*) of Phai^tiiis triungulari'^ (l'^3) is not really separated 

 from the episteruum (Eps), and forms a large lobe in front of 

 the wing process (WP). Here the base of the wing process sends 

 a long arm (153, 154, f{/A) forward and upward to support the 

 tegular plate of the notum (150 f(/). This, however, is peculiar 

 to the Lepidoptera. It will be observed that in all cases the true 

 wing proco-^s can be identified by the fact that it is derived from 

 both the episteruum and the epimerum, while the process formed of 

 the parapteruui is connected onh^ with the episteriunn. 



The postparapterum or epimeral parapterum (text figs. 3, 4, o P) is 

 of less importance than the preparaj^tera. It is a small plate of 

 irregular and variable shape lying in the membrane of the base of 

 the wdng behind the wdng process of the pleurum. It is often lack- 

 ing, being never present in beetles. It is illustrated in the Corro- 

 dentia (82, 3 P), the Trichoptera (146, 148, S P), the Lepidoptera 

 (149, 153, 154, 3 P), and the Diptera (174, 176. 179, 3 P). 



In a few of the lower orders a plate frequently occurs before the 

 episteruum (text figs. 3, 4, Peps). This is the sclerite wdiich Verhoeff 

 (1903) calls the " katopleure '" in the Euplexoptera (Dermaptera) and 

 it is well shown in this order by Spongipliora (94, Peps). But the 

 plate which Verhoeft' so designates in the Blattidse (32, 35, eps) would 

 .■^eem to be only a subdivision of the episteruum {Eps) not compara- 

 ble with the sclerite in Euplexoptera. The writer formerly (1908) 

 ado])ted the name " katopleure " for this sclerite, but here substitutes 

 the more appropriate term preepistermim suggested by Dr. A. D. 

 Hopkins. Tlie preepisternum falls in line with the presternal ele- 

 ment {Ps) of the ventral parts (text fig. 3, Peps and Ps). 



The preepisternum is illustrated in the prothorax (26, Peps) and 

 the mesothorax (27, 28) of Spodromantis guttata (Mantichc), in the 

 mesothorax (35) of Ischnoptera hyalwa (Blattidse), in the meso- 

 thorax (43, 44) of xlnahi'us simplex, (Locustidse), in the mesothorax 

 (47) of Gvyllus pennsylv aniens (Gryllida'), in the nymphal meso- 

 and metathorax (55, 56) of Melanoplus., in the adult (57) of Hippis- 

 ciis p/io'jucopterus, and the adult (70, 71) of Dlssosteira Carolina 

 (Acridiida^), and finally in the mesothorax (94) of Spongiphora 

 apicidentata (Forficulida^). It does not appear to be present in the 

 higher orders, though anterior subdivisions of the episteruum occur, 

 especially in the mesothorax of Coleoptera (102, 107, 109). Such 



