^O. Gt] DIPTERA OF CONNECTICUT: MORPHOLOGY 53 



middle coxae, and furnishing a solid connection with the sternal 

 region as well. 



The basalar sclerites (sometimes incorrectl}^ called the "parap- 

 tera"") are the small sclerites situated near the base of the wing, in 

 the dorsal region of the anepisternum, aes. The posterior basalar 

 sclerite is usually attached to the upper portion of the anepisternum, 

 but the anterior basalar sclerite, {iba of Fig. 6, A, C and E, is a small, 

 Separate plate, which is sometimes connected with the notum by a 

 narrow strip (the prealar bridge), extending in front of the base of 

 the wing, as is the case in the tipulid shown in Fig. 6, A. The basalar 

 sclerites are located in front of the alifer, or pleural fulcrum of the 

 wing, and the sclerite, sf of Fig. 6, C and E, is located immediately 

 below the pleural fulcrum of the wing. 



The katepisternum, or "sternopleura", kes of Fig. 6, A, B, and 

 C, is the lower portion of the episternum, which is usually interpreted 

 as the anterior region of the mesosternum in the Diptera. It is close- 

 ly united with the sternal region, and when the sternal region be- 

 comes inroUed in the mid-ventral line (forming a median endoster- 

 nal [)artition anterior to the base of the furca) the katepisternum 

 may extend ventrad almost as far as the middle of the ventral region 

 of the mesothorax. 



In the culicids (Fig. 6, D) a sclerite, j^Pn, corresponding to the 

 ;;pleurotrochantin of other insects, occurs in the lower portion of the 

 jepisternal region, and is overlapped by a fold of the integument above 

 it. Young (1921) mistakes this sclerite for the combined meron and 

 ['lower region of the epimeron (meropleurite), and interprets the 

 Mmesothoracic meron, 7ne, as the episternum of the metathorax in his 

 figures of the thoracic sclerites of the culicids, although his interpre- 

 tations of the dipterous thorax in other respects are usuall}^ quite 

 ai'i'urate. 



The anepimeron, or ''pteropleura", aem, is rather faintly demarked 



I from the rest of the epimeron in the tipulid shown in Fig. 6, A, but 



'in most of the higher Diptera (Fig. 6, C), there is a distinct .suture 



, (the anepimeral suture) between it and the lower portion of the epi- 



f meron, which unites with the meral region to form the composite 



region labelled 7npl in Fig. 6, C. The anepimeral region is divided 



into an anterior and posterior region by a vertical subalar suture, 



labelled sas in the mycetophilid shown in Fig. 6, B, but the anepimeral 



region is not demarked from the lower portion of the epimeron in 



this insect, or in the culicid shown in Fig. 6, D. An apodemal pit, 



however, occurs in the pleural suture, ps, just in front of the label eni 



of Fig. 6,B, at the level of the suture which divides the epimeron 



into an upper and lower region in the higher Diptera. 



A subalar plate, sa, frequently occurs in the subalar membrane 



between the insertion of the wing and the dorsal portion of the epi- 



meral region. This plate is sometimes called the epimeral "parap- 



;teron", while Hewitt (1914) and Lowne (1890) call it the "costa" 



(a term usually applied to a vein of the wing). In some syrphids a 



