THE GENUS ACRONYCTA AND ITS ALLIES. 221 



failed to do an3'thing, as but few eggs were laid, and many of 

 these were infertile. I concluded that from in-breeding or 

 domestication they were dying out. This year (1892), how- 

 ever, the broods were large and healthy, but, unfortunately, I 

 had not leisure to observe them properly at the right time. A 

 certain portion of pupcne usually remain over a second year, and 

 I had this spring, pupa^ of two years ; however this may have 

 affected the matter, it is somewhat curious that with no fresh 

 blood introduced, the race should regain vitality and fertility. 



To pupate, the larva likes to get under a dead leaf or other 

 similar object, and makes a cocoon of loose matters on the 

 surface of the ground ; I succeed in making them spin up in 

 sawdust, but they always do so close to the surface, and often 

 aggregate their cocoons together. The cocoon is moderately 

 firm, made with a pale reddish brown silk, and always has a 

 ^•ery flimsy portion opposite the head ; it is smooth, but not 

 polished inside ; the flimsy portion, seen from within, has 

 hardly any silk, and the cocoon materials are held together by 

 the larval hairs, which are interwoven with the cocoon through- 

 out, and here hold the materials together, some of them being 

 held by the silk round its margin. When the moth emerges, 

 these hairs project more or less from the opening. 



The pupa (PI. I., figs. 4, 4a; PI. IV., figs. 3a, 3b, 3c) is of 

 the brown, corneous, brittle-looking texture, common among 

 NocTU.E, but is firm and robust, length 15 mm. (wing portion 

 10 mm., abdomen 5 mm.), and breadth 5 mm. The wing 

 portion fairly cylindrical, but slightly swelling towards the 8th 

 segment, the 3rd also full, and the anterior tibite rather pro- 

 minent ; the abdominal segments taper regularly, but not so 

 much as usual, the termination being broadly truncate instead 

 of sharp. The brown colour becomes nearly black dorsall}- ; 

 the surface is highly polished, the wing and leg covers rather 

 less so, being transversely striate, as is also somewhat the 

 thoracic dorsum. The 2nd segment has a central ridge dividing 

 two polished almost specular surfaces. The feature of the 

 pupa is the sculpturing of the anterior borders of the 

 segment most marked on the free borders of g, 10, 11, 

 contrasting with the glassy polish of the rest of the surface. 

 It consists of a sharp raised margin, with a groove behind 

 it, the groove being formed by a series of pits, to the 

 number of 16 or 18, across the dorsum from spiracle to 

 spiracle, the sharp ridge being depressed opposite each pit. 

 Ventrally, these pits merge into a row of the ordinary small 



