AMERICAN DIPTERA. 221 



well as by an anterior one (fig. 161). The posterior margin is 

 notched and each side of the notch bears a transversely elongate 

 lobe. 



The pleura are separate from the sternum. Each consists basally 

 of an ordinai'y triangular plate, but the posterior margin is pro- 

 longed into a long curved arm ending in a large spatulate expan- 

 sion (fig. 160). In this character the species strongly resembles 

 Tipula streptocera. 



There is but one terminal appendage on each side, but it proba- 

 bly is composed of both the second and the third appendages (fig. 

 159). It consists of an anterior and a posterior part. The former 

 (B) is a wide plate with a blunt anterior tip and reflexed anterior 

 margin, so that there can be no doubt that it is the ordinary second 

 appendage. The latter is a triangular lobe (C) on the posterior 

 edge of the base of the othei', and is partially divided into several 

 finger-like lobes. 



The guard of the penis (fig. 158) is a simple, decurved, tapering 

 process with a wide groove above. In this groove are two elongate 

 lamelliB inclosing the penis between them. Their posterior tips pro- 

 ject from the groove, as a separate process, above the tip of the main 

 part of the guard. The central vesicle and penis have ordinary 

 forms. 



Tipula dorsoliiieata Doane (PI. XII, figs 72, 74, 75). 



The terminal part of the abdomen is bent upward, but the hypo- 

 pygiuin does not form an enlargement of it. The eighth segment is 

 wider than the ninth, and both tergum and sternum are large. The 

 tergum of the hypopygium is deeply emarginate posteriorly, and is 

 separated from the sternum by a wide membranous suture (fig. 72). 

 The sternum is almost entirely separated into two lateral plates by a 

 deep, narrow, median notch occupied by membrane. A pleural 

 sclerite is present as a rounded lobe on the upper posterior angle of 

 each half of the sternum. There are three apical appendages on 

 each side. The first is large and spatulate, bent posteriorly (figs. 

 72 and 74, A). The second and third arise from a common base. 

 The second is an elongate cylindrical lobe with an enlarged head 

 bearing a short hook (B). It is mostly concealed by the first. The 

 third arises on the outer side of the base of the second and projects 

 posteriorly. It is spoon-shaped, with the concavity inward. 



TBANS. AM. KNT. SOC. XXX. JULY. 1904. 



