PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 52. 



the metathorax is the metanotuin, more commonly called the post- 

 scutellum. The true first segment of the abdomen is solidly fused 

 with the thorax and is variously termed the median segment, middle 

 segment, or propodeum. In some of the earlier descriptions of 

 species the dorsum of this segment is erroneously called the 

 metanotum. 



The term abdomen is applied to that part of the body which is 

 posterior to the median segment and movably attached thereto. 

 Although this is, as a matter of fact, an incorrect use of the term, I 

 have adhered to a practice that has been universal, and conse- 

 quently the segment that is herein called the first abdominal seg- 



/3 /+ 



Wings of Stictia Carolina fabricius.— Veins: 1, costal; 2, basal; 3, discoidal; 4, subcostal; 5, 

 medlvn; 6, submedian; 7, submedian cross= transverse median of Cresson; 8, radial; 9, third 

 cubital cross; 10, second cubital cross; 11, first cubital cross; 12, cubitus; 13, first discoidal 

 cross=fmst recurrent of cresson; 14, second discoidal cross= second recurrent of cresson. 

 Cells: A, costal; B, radial; C, first cubital; D, second cubital; E, third cubital; F, median; 

 G, submedian; H, second submedian => second discoidal of Cresson; I, first discoidal; J, second 

 discoidal= third discoidal of Cresson; K, anal; L, basal lobe; M, basal sinus; N, anal sinus; 



R, RETINACULUM. 



ment is in reality the second. Each abdominal segment is composed 

 externally of an arched dorsal plate and a flat ventral plate ; the former 

 is termed the tergite, the latter the sternite. The abdomen of the 

 female is composed of six visible segments ; that of the male of seven. 

 The eighth segment of the male is concealed and bears the genitalia. 

 The sixth tergite of the female in some species shows a more or less 

 conspicuous lateral ridge at either side and when these ridges are 

 present the area between them is termed the pygidial area or pygi- 

 dium. The second sternite of the male, or the second and also the 

 sixth, frequently shows a median special structure various in form 

 and variously referred to as a process, tubercle, tooth, or spine. 



The wings lie flat when at rest and the general type of venation 

 is shown in the sketch above. 



