280 LEPIDOPTERA. 



partially clavate, as in Zygsena. The wings are long and nar- 

 row in the typical genera, becoming shorter and broader in the 

 lower genera, such as Euremia, from India. The scales are 

 fine, powdery and scattered thinly over the surface, often leav- 

 ing naked spots on the wings. The species are usually green 

 or deep blue, with scales of purplish black, or entirely black, 

 alternating with gay colors, such as golden, bronze, or white 

 and red. They fly in the hot sunshine. 



The sixteen-footed, greenish larvae are short, cylindrical, the 

 body being obtuse at each end. The head is veiy small and 

 when at rest is partially drawn into the prothoracic ring. The 

 segments are short and convex, with transverse rows of un- 

 equal tubercles which give rise to thin fascicles of very short 

 and evenly cut hairs, which are often nearly absent. The 

 larvae are either naked, as in Alypia, Eudryas and Castnia, or, 

 as in the lower moth-like species, they are hairy, like those of 

 the Lithosians and Arctians in the next family. Before trans- 

 forming, the larvse usually spin a dense, silken cocoon, though 

 Eudryas and Castnia make none at all, and Ctenucha a slight 

 one of hairs. The pupa of Zygsena, especially, is intermediate 

 in form between that of jEgeria and Arctia, being much 

 stouter than the first, and somewhat less so than the last. 

 The head is prominent, and the tips of the abdomen sub-acute. 

 Ctenucha is more like Arctia, while Castnia and Alypia are 

 elongate, slender, with the head made especially prominent by 

 a tubercle on the front of the clypeus. 



In common with the Sphingidce, and ^Egeriadce, the 

 Zygsenidse are confined to the temperate and tropical regions. 

 The family type, Zygcena, has its metropolis about the Mediter- 

 ranean Sea, and thence spreads to the north of Europe, and 

 southward to the Cape of Good Hope. Zygcena exulans is 

 found as far north as Lapland, and in vertical distribution rises 

 6,000 to 7,000 feet in the Alps of Styria. 



Castnia is, however, a tropical American genus. Alypia is 

 the most northern genus, extending into the Hudson Bay ter- 

 ritories. Glaucopis and allies, which comprise a large number 

 of species, are almost exclusively tropical American. In Aus- 

 tralia, as Klug observes, Castnia is represented by Synemon. 

 The American genus Eudryas is represented by very closely 

 allied South African genera. 



