AMEPvICAN DIPTERA. 219 



There are three apical appendages (lig. 110). The first (A) is 

 flat and expanded distally, contracted into a slender peduncle Imsally. 

 The middle lobe (B) is a wide triangle with a thick basal stalk. 

 On the outer side of the basal two thirds of its anterior edge is a 

 reflected elevation of the margin. The third lobe (C) arises from 

 the posterior edge of the base of the second. It is short, wide and 

 triangular, but is attached by one side. It bears a fringe of very 

 long hairs. 



The central vesicle and penis are of ordinary forms. The guard 

 of the penis (fig. Ill, p. g.) is a simple, slightly decurved, taper- 

 ing, stylet like process arising from the floor of the genital cham- 

 ber just above the posterior end of the median membranous area of 

 the sternum. Its upper surface bears a deep longitudinal groove. 

 Just below its base there arise two large, heavy, chitinous append- 

 ages (fig. Ill, rt) projecting posteriorly and dorsally (upward and 

 forward in actual position). A little beyond its middle each is 

 abruptly thickened by a lobe like ventral swelling. Beyond this it 

 tapers to a slender, slightly decurved point. Below the bases of this 

 pair of appendages there arises a single median appendage. This 

 one arises from two converging basal rami, is thick basally, taper- 

 ing and decurved distally, and ends in a small, transverse, triangu- 

 lar, arrow- head-like plate. The structure of the guard and the 

 appendages below it is, thus, very similar to that of Tipula bisetosa 

 (cf. figs. 107 and 111). The apical appendages are also very similar 

 (cf. figs. 104 and 110). The general external shape of the hypopy- 

 o-iuin, however, is different, and in T. bisetosa the pleural plates are 

 not separated from the sternum (cf. figs. 10(5 and 109). 



Tipula streptocera Doane (PI. XIV, figs. 102, 103, 105). 



The eight sternum is very large, being high on the sides and 

 greatly prolonged posteriorly beneath the hypopygium. The poste- 

 rior margin bears two short, thick, articulated, clavate lobes nor- 

 mally directed upward (fig. 102, a). The eighth tergum is a very 

 small, semi circular plate covering the base of the dorsal surface of 

 the hypopygium. 



The hypojiygium itself is rather small and is irregularly globular. 

 Its walls consist principally of two large lateral plates, which are 

 the lateral parts of the sternum with, perhaps, the tergum united. 

 The two plates are separated along the mid-dorsal line by a narrow 



TEANS. AM. ENT. SOC. XXX. JULY. 1904. 



