MUSCULATURE OF DIPTERA — SMART 345 



This muscle runs from the anterior anterodorsal margin of the 

 anepisternum to the anterior face of the basalar plate. 



b. Inferior episternal basalar muscle. 



Other names are : Sternal basalar muscle "2E" (Snodgrass), "pro- 

 nator alae" (Ritter), sternobasalar muscle (Maki), pleural muscle 

 of the basalar (Bonhag), basalar muscle ("51") (Miller in Demerec). 



Maki (1938) and Bonhag (1949) both describe this muscle as 

 double. It is single in Anisopus and runs from the line of junction 

 of the sternopleuron with the episternum to the basalar plate. 



As pointed out above, the muscle 7, a, could be grouped with the 

 two preceding muscles inserting on the basalar plate. 



There is no muscle running from the basalar plate to the trochanter 

 and acting thereon as an extracoxal depressor thereof. 



9. AXILLARY MUSCLES (fIG. 4). 



There are three multiple axillary muscles. All have their origins, 

 which in some cases are very broad, on the pleural wall, and all insert 

 on one or other of the sclerites of the wing base. Tension applied to 

 the tendons of insertion must affect the way in which the various 

 articulations work on each other and so, in fact, alter the setting of 

 the wing in the course of its stroke, thus changing the mode of flight 

 of the fly. 



a. Axillary muscle of ist sclcrite. 



Other names are: Axillary muscle of ist axillary sclerite (Snod- 

 grass), 1st levator of the wing muscle (Ritter), pleuroaxillary muscle 

 of 1st sclerite (Maki), pleural muscle of ist axillary sclerite (Bon- 

 hag), muscles of ist sclerite (Miller in Demerec). 



This muscle is double. The main branch arises on the sternopleuron ; 

 a minor branch, not visible in figure 4, originates on the dorsal part 

 of the pleural sulcus. Snodgrass (1935) states that this muscle is 

 found only in Diptera. 



b. Axillary muscle of 3d sclerite. 



Other names are : Axillary muscle of the 3d axillary sclerite (Snod- 

 grass), 2d levator of the wing muscle (Ritter), pleuroaxillary muscle 



