188 



Forty-second Report on the State Museum. 



[46] 



thereafter. This peculiarity has been noticed in Aotias Luna and 

 others of our Bombycids, and in Aglia tau of Europe.* If shared by 

 many of the Cochlidice, it may be the explanation of the failure that 

 so generally attends the efforts to rear their larvae to the imago stage. 



The cocoon is oval and parchment-like, as are those of Euclea, 

 Empretia, and Limacodes, which are more frequently met with. In 

 nature, it is said to be formed usually between leaves. Confined in 

 a box, it is quite as often attached to the sides as to the leaves 

 that may be therein. The one fed by me on hazel spun its 

 cocoon on the surface of some damp sand, fastened to the twig stand- 

 ing therein. The outside of the cocoon was covered with grains of 

 sand, and in its upper portion were interwoven some of 

 the long arms which have been described as characteristic 

 of the larva. It was broadly oval, slightly flattened on 



the sides, measuring three-tenths of an inch by four- 

 FlG.12— Co- ... & . , . , J 



cooh of the tenths, being about the form and size shown m the 



hag-moth accompanying figure, although described by Mr. 

 Phobetron Hubbard as "almost spherical — bullet-shaped." Com- 

 pithecium. pared with Empretia stimulea Clemens, it is less elon- 

 gated, for in that we have the proportion of 0.32 to 0.50 in. 



The attachment of several of the hairy arms of the caterpillar to its 

 cocoon, which is usually a feature of it, is probably the result of the 

 chance projection of the arms through the meshes of the frame-work of 

 the cocoon, the difficulty of withdrawing them with the threads clasp- 

 ing their contracted base, and the ease with which they would be torn 

 off in the contortions of the caterpillar in its close quarters, seemingly 

 so disproportionate to its size. This dismemberment of its ornamental 

 appendages, so often remarked upon by writers, would, therefore, 

 appear to be involuntary and a necessity, rather than intentional, 

 and for any purpose that it might serve in the economy of the 

 insect. 



The cocoon, in giving out its moth, opens by a circular lid in one 

 end, made for the purpose by the larva during the construction of the 

 cocoon. With no example at hand for examination, I am not able to 

 state whether the lid displays even an approach to the remarkable 

 ingenuity shown by the Lagoa crispata larva in the building up of the 

 lid of its cocoon with hinge and an inner guard to protect from out- 

 ward pressure.f 



* Entomological Contributions, No. Ill — Twenty-sixth Kept. N. Y. St. Mus. Nat Hist, 1874, 

 p. 153. 



t Entomological Contributions, No. II, 1872, p. 38— Twenty -fourth Rept. N. Y. St. Mus. Nat. 



ffist, 1872, p. 142. 



