PHRYGANEID^. 



621 



is very long, filiform and multiarticulate. In Mydropsyche the 

 spurs are arranged thus : 2, 4, 4, The antennae are rather 

 long and slender, the ocelli are absent, and the intermediate 

 feet of the female are dilated. H. scalaris Hagen is black 

 gray, with white hairs, and the antennae are yellowish, and 

 obliquely striated with black at the base ; the first joint is 

 covered with snow-white hairs. Philopotamus has three ocelli, 

 and the tibial spurs are arranged thus : 2, 4, 4. 



In Rhyacophila the maxillary palpi have the last joint entire, 

 straight, shorter than the rest ; while there are three ocelli, and 

 the tibial spurs are arranged thus : 3, 4, 4._ R. fuscula Walker 

 is rust-red, with some black hairs and a subfuscous spot on 

 each side of the thorax. It comes from Hudson's Bay. 



Another curious Neuropterous insect found in the iron-stone 

 concretions of Morris, 111., is the Megathentomum j^ustulatum 

 of Scudder (Fig. 617, natural size), described and figured by 

 him in the "Palaeon- 

 tology of the Illinois 

 State Geological Sur- 

 vey." "The fragment 

 represents a wing (ap- 

 parently an upper one) 

 of a Neuropterous in- 

 sect. It is gigantic in 

 size, very broad, with 

 distant nervures, sim- 

 ple infrequent divarica- 

 tions, and in the outer 

 half of the wing, which 

 alone is presented, a 



Fig. 617. 



cross neuration, composed solely of most delicate and irregu- 

 lar veinlets. The wing is also furnished with a great number 

 of larger and smaller discolored spots, the surfaces of the 

 larger ones irregularly elevated." Mr. Scudder thinks the 

 wing IS allied to that of Coniopteryx, adding "it appears to 

 belong to a family hitherto undescribed. I do not know of a 

 single insect, living or fossil, which approaches it in the struc- 

 ture of the wings." 



