FAMILY ZYG^ENIDjE. 25 



last is very large and truncated at the apex. The clypeus in 

 front is square. Palpi large, porrect ; two basal joints evenly 

 pilose to the tip of the second. Third joint small, cylindrical, 

 short, porrect reaching nearly one-half its length beyond the 

 front. 



Thorax pilose, with a broad median crest of metallic-colored 

 scales, succeeded by a dorsal row of similar tufts upon the basal 

 half of the abdomen which diminish in size from the thorax. 



Wings shaped as in Alypia, but the primaries are more 

 rounded at the apex, internal angle rounder. The nervules are 

 nearly continuous with the direction of the main branches. Sub- 

 costal nervules long, first subcostal arising one-third of the distance 

 out to the apex of the wing. The hind wings hardly reach to the 

 outer fourth of the abdomen, being much as in Alypia. Outer 

 margin a little scalloped below the apex, below straight and 

 parallel with the costa of the primaries. Discoidal nervules 

 situated within the middle of the wing. The femora and tibia) 

 of the fore-legs are very pilose, forming a dense tuft projecting 

 in a mass over the first tarsal joint. Hind pair of legs stout, 

 with longer tibial spines than in Alypia. 



The very intimate relationship of this genus to Alypia may 

 be better seen after a more detailed comparison. 



The head of the genus under consideration is much larger, 

 the eyes are nearly twice larger, more globular, and occupy a 

 larger extent of the sides of the head. The whole front of 

 Alypia is proportionally narrower than that of Eudryas, the 

 ocelli and antennae are therefore more approximate in the former 

 genus. The occiput is much developed in Alypia, occupying a 

 much larger area than in Eudryas, where it forms but a narrow 

 rim. The convex epicranium is larger in Eudryas, being twice 

 as broad as long, and having a slight ridge between the ocelli. 

 In Alypia it is nearly two-thirds as long as broad, convex, and 

 narrow in comparison with Eudryas. The clypeus in Alypia 

 is very distinctly rectangular, the sides being exactly parallel, 

 and the angles well pronounced, while the same piece in Eudryas 

 narrows rapidly anteriorly, is longer than broad and has the 

 angles of the anterior edge a little rounded. Both genera pos- 

 sess a large truncated conical tubercle rising from the surface of 

 the clypeus a little in advance of the middle, but it is smaller 

 and slenderer in Alypia. 



ESSEX INST. PROCEED. VOL. IV. D. 



