AMERICAN DIPTERA. 201 



Paehyrrhina erythrophagus. 



The general shape of the abdomen and the hypopygium is very 

 similar to that of the last species. The suture separating the pleu- 

 rum from the sternum, however, is shorter and is curved upward at 

 its anterior end for a very short distance. The upper apical append- 

 age is wider than in the last species, the inner is more tapering. 



Pachyrrhina incurva Loew (PI. XI, figs. 52, 53). 



The abdomen is club shaped as in the last two forms, the hypopy- 

 gium not forming an abrupt enlargement. 



On the sides of the hypopygium a strongly bent suture (fig. 53) 

 partially separates the pleurum from the sternum. There are two 

 apical appendages, the outer and upper one is elongate and slender, 

 the lower is large, flat, with several irregular processes projecting 

 upward. 



In this species the penis is greatly prolonged, reaching forward 

 into the first segment of the abdomen. The central vesicle lies very 

 close to the floor of the genital chamber. From it the penis first 

 curves upward (fig. 52) to the dorsal part of the abdomen, it then 

 turns anteriorly and extends into the first abdominal segment. Here 

 it makes a small loop veutrally, doubling upon itself and then again 

 goes posteriorly close along the forward running arm. Posteriorly 

 it descends past the anterior part of the central vesicle and finally 

 turns posteriorly close upon the floor of the genital chamber. The 

 posterior end is held in the guard of the penis. A delicate sheath, 

 consisting of a tubular evagi nation from the genital chamber, 

 contains the two arms of the loop of the penis. 



The guard of the penis is a simple tapering process (fig. 52, p. g.) 

 grooved above, arising from the floor of the genital chamber above 

 the posterior edge of the sternum. Two free tapering arm-like pro- 

 cesses extend downward and posteriorly from its base. 



Pachyrrhina peduncnlata Loew (PI. XI, figs. 57, 58, 59). 



Externally the abdomen is very simple, being evenly enlarged 

 toward the posterior end. 



The tergum of the abdomen is notched mesially in the middle line 

 and on each side of this the margin is produced into a small point. 

 The sternum is undivided below, but the median part is membran- 

 ous. The pleurum is separated posteriorly from the sternum by a 

 suture angularly bent upward at the anterior end (fig. 59). 



TRANS. AM. ENT. 80C. XXX. (26) JULY. 1904. 



