24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



Laterally from the two dorsal muscles, there are three powerful 

 dorso-ventral muscles (text figs. 4, 5; pi. 4, fig. 32, dv), each of 

 which,appears to be composed of four parts. The first three I desig- 

 nate with the numbers from 1 to HI. The fourth is apparently not 

 a muscle of flight. 



The musculus dorso-ventralis I (text fig. 5; pi. 12, fig. 32: 

 dvl) is the strongest. It extends from the dorsal portion of the 

 prasscutum to the mesosternum. 



The musculus dorso-ventralis IT (text fig. 5 ; pi. 12, fig. 32 ; dvll) 

 extends from the rostral portion of the scutum to the metasternum. 



The musculus dorso-ventrahs III (text fig. 5; pi. 12, fig. 32; 

 dvIII) is attached to the scutum behind the musculus dorso- 

 ventralis II, and extends to the "tympanic plate" of Lowne (s. 1., 

 1890-1892, t. 7, figs. 2, 24), to the thickened margin of which it 

 is fixed. 



The fourth dorso-ventral muscle (text fig. 5 ; pi. 12, fig. 32, 

 pi. 13, fig. 33; tr), which is much the weakest of the four, must, 

 from its position, be considered as a leg muscle. It arises from the 

 scutum, at the edge of the prsescutum, lies under the turbinate 

 process of the mesapophysis, and is inserted on the trochanter of 

 the second pair of legs. 



As an indirect muscle of flight the broad, ribbon-like musculus 

 latus is also to be mentioned. It lies between the mesapophysis 

 and the mesapodema. 



B. DIRECT MUSCLES 



As mentioned above, ten direct muscles are to be distinguished 

 on either side. 



1. The adductor alee (text fig. 6; pi. 13, fig. 33; md). This 

 muscle arises in the shape of a broad band from the mesapodema. 

 Gradually attenuated, it extends to the foramen postalaris. It then 

 becomes tendinous and passes through this foramen and is con- 

 tinued beyond in the ligamentum postalare, stretched out between 

 the processus pteraUs thoracis VI, the processus pteralis alae 4, the 

 processus postalaris and the pterale A. 



2. The abductor alee primus (text fig. 6; pi. 13, fig. 33; mhl) . 

 This muscle arises from the point where the parapleurum, the 

 stigma anterius and the prasscutum come in contact, close under 

 the praescutellar edge. The muscle follows this edge, becomes 

 broader distally, and attaches itself to the parapterum. 



3. The levator alee primus (text fig. 7, pi. 11, fig. 30, pi. 13, fig- 

 34; mel). This nuiscle is delta-shaped. It arises at the ventral, 



