NO. I 



INSECT THORAX SNODGRASS 



103 



E, basalar coxal muscle, direct ex- 



tensor of wing. 

 Epl, eupleuron. 

 Epm, epimeron. 

 epm, subdivision of epimeron. 

 Eps, episternum. 

 cps, subdivision of episternum. 



F, subalar coxal muscle, direct ex- 



tensor and depressor of wing, 

 femur. 

 Fs, furcisternum. 

 Fu, furca, the sternal apophyses united 



on median base. 



G, muscle from pleural apophj'sis to 



sternal apophysis. 

 Gc, jaw segments of head, gnatho- 

 cephalon. 



H, head. 



longitudinal ventral muscle. 



1, promoter muscle of coxa. 

 I-XII, abdominal segments. 

 IS, first abdominal sternum. 

 ISg, intersegmental groove. 

 IT, first abdominal tergum. 



/, remotor muscle of coxa. 



K, anterior rotator muscle of coxa. 



P , thoracic branch of depressor muscle 

 of trochanter. 



Par, parapsis, parapsidal ridge. 



par, parapsidal suture. 



Pc, precosta, anterior marginal lip of 

 segmental plate before ante- 

 costal ridge and suture. 



Pcx, postcoxal bridge. 



Ph, phragma. 



PI, pleuron. 



PIA, pleural apophysis. 



pla, external root of PIA. 



PIR. pleural ridge. 



PIS, pleural suture. 



PA'', postnotum (postscutellum) post- 

 alar tergal plate of winged 

 segment, bearing phragma, con- 

 sisting of precosta and posterior 

 lip of phragma, usually detached 

 from following tergum. 



PNP, posterior notal wing process. 



Pph, posterior phragma. 



PR, ridge between prescutum and 

 scutum. 



Pre, procephalon (primitive head, not 

 including jaw segments). 



PS, poststernum (postfurcisternum 

 and spinisternum). 



ps, prescuto-scutal suture. 



Psc, prescutum. 



Ptar, pretarsus. 



Piv, postalar bridge. 



L, leg. 



posterior rotator muscle of coxa. 

 LMcl, longitudinal muscles. 



M, abductor muscle of coxa. 



media, fourth vein of wing. 

 Mb, " intersegmental " membrane. 

 mb, secondary " intersegmental " mem- 

 brane behind base of phragma. 

 Mcr, meron. 

 Mth, mouth. 



A^ adductor muscle of coxa. 



O, levator muscle of trochanter. 

 Op, operculum. 



Q, coxal part of depressor muscle of 

 trochanter. 



R. radius, third vein of wing, 

 reductor muscle of femur. 

 Rd, posterior fold, reduplication, of 



tergum. 

 rd, anterior ventral margin of Rd. 



S, levator muscle of tibia. 



sternum. 

 SA, sternal apophysis. 

 Sa, subalare, epimeral epipleurite 



(paraptcron). 

 sa, external root of sternal apophysis. 

 Sc, subcosta, second vein of wing. 



