xx SIALIDAE AND SCORPION-FLIES 449 



at each end so as to form elongate loops ; the mesenteron is very 

 complex in character. 



A considerable number of fossil re- 

 mains from both Tertiary and Mesozoic 

 strata are referred to Sialidae ; and a 

 larval form from the red sandstone 

 of Connecticut has been considered by 

 Scudder to be a Sialid, and named 

 Mormolucoides articulatus, but the cor- 

 rectness of this determination is very 

 doubtful (Fig. 293). These fossils are, 

 however, of special interest as being the 

 most ancient Insect larvae yet brought 

 to light. A still older fossil, from the Car- 



i .p ,. TV |. . fi j -, f . . FIG. 293. Mormolucoides 



bonilerous strata ot Illinois called Miamia articulatus larva. Trias 

 bronsoni, is considered by Scudder to have of Connecticut. (After 

 several points of resemblance to Sialidae. 



Fam. IX. Panorpidae Scorpion-flies. 



Head prolonged to form a deflexed beak, provided with palpi near 



its apex; wings elongate and 

 narrow, shining and destitute of 

 hair, with numerous, slightly 

 divergent veins and moderately 

 numerous transverse veinlets (in 

 one genus the wings are absent}. 

 Larvae provided ivith legs, and 

 usually with numerous prolegs 

 like the saw-flies : habits car- 

 nivorous. 



The majority of the members 

 of this family are very readily 

 distinguished by the beak -like 

 front of the head, this being 

 chiefly due to enlargement of 



FIG. 294. Panorpa commums, male. 



Cambridge. parts of the head itself, and 



in a less degree to prolongation 



of the mouth-parts. The upper (or front) face of the beak is 

 formed entirely by the clypeus, the labrum being scarcely 

 VOL. v 2 G 



