NO. 1687. THE THORAX OF HSiBECTH—tiXODilliAtiti. 577 



or fused into one jjlate. An anterior phragma on any segment is a 

 prephragma (Aph) and a posterior phragma a postphragma (Pph). 

 A tergiim ma}' be provided with both, but the postpliragma is nearly 

 always the larger. AVhen a pseudonotum is presL'nt it carries the 

 postphragma. (See Prephragma and Postphragma.) Phragma 

 Kirby and Spence (182G), Packard (1898). 



Pleural arm {PA). — The arm of the pleural ridge present in some 

 form in most insects and usually connected with the corresponding 

 arm of the sternal furca of the same segment. Apode7nzmken Voss 

 ( 1905 ) . Processo pleurale Berlese ( 1906) . Ad f ureal process Cramp- 

 ton (1909). 



Pleural coxal proeess (CxP). — The condyle at the lower end of 

 the pleural ridge to wdiich the coxa is articulated. Absent in only a 

 few cases, though often hidden by overlapping extensions of the 

 joleurites. Apophyse pedio-pleurale k.vi\2irvs (1888). Coxalgelenkkopf 

 Voss (1905). Condilo pedif era Berlese (1906). Coxal process Snod- 

 grass (1908), Crampton (1909). 



Pleural ridge (PP). — The internal ridge developed along the 

 jileural suture between the episternum and epimerum. Dorsally it 

 forms the pleural icing process {WP) and ventrally the pleural 

 coxal process {CxP). Internally it carries the pleural arm iPA). 

 All of these jDarts together may be regarded as constituting the 

 entopleurum. ^Ti^o^ZewroTi Amans (1885), Crampton (1909). Pleu- 

 ralleiste Voss (1905). Apodem Kolbe (1889). Pleurale Berlese 

 (1906). 



Pleural suture {PS). — The external suture between the episternum 

 and epimerum, extending from the wdng process to the coxal process. 

 Pleuralfurche Voss (1905). Pleural suture Snodgrass (1908), 

 Crampton (1909). 



Pleural wing process {^YP). — The process formed by the upper 

 end of the pleural ridge, formed of elements derived from the 

 episternum and epimerum, which forms the pleural support of the 

 wing, the latter articulating with it by means of the second axillary 

 sclerite. Uappui de Vaile or claricula thorachique Chabrier (1820). 

 Alifere Straus-Diirckheim (1828). Clavicula alee Lendenfeld 

 (1881). Apophyse alifere and pivot fixe or median Amans (1885). 

 Ascending process Lowne (1892). Pleuralgelenhkopf Voss (1905). 

 Fulcro alifero Berlese (1906). Alar process Crampton (1909). 



Pleurites {E]}s, Eprn^ Peps^ P, Tn). — The sclerites constituting 

 any pleurum. (Frequently used as synonymous with pleura.) 



Pleurum {PI). — The morphological lateral surface of any seg- 

 ment — the chitinous area on the side between the tergum and sternum. 

 Clav'iculcs anteriores in mesothorax, plaques fulcrales in metathorax 

 Chabrier (1820). Pleuroi k.\xdo\\m (1824). PZewron Amans (1885), 

 Crampton (1909). PZe?//vwi Comstock and Kellogg (1902). 

 Proc.N.M.vol.xxxvi— 09 37 



