Dec, 1905.] 



Chelanops oblongus. 



415 



within, supported by several fibres of silk which cross and 

 recross the enclosed space, becomes torpid and moults in two or 

 three davs. It then remains in its nest for one or two days 

 longer, or until its cuticle hardens, when it is ready to break 

 through the wall of its little prison. (See notes Jar C above; 

 also figure.) 



Some writers convey the idea that these nests are built by 

 the mother for the entire brood after they leave the pouch, and 

 that they remain there until sufficiently hardened. Judging by 

 mv own observations this is not the case. I have never found 

 l)ut a single specimen in a nest of this kind, and that always an 



Fig. I. Moulting Nest of Chelanops oblongus. 



immature one. (I collected and observed not less than two 

 dozen such nests.) Furthermore, I usually found the empty skin 

 in the nest and sometimes the skin and the animal, in fact I all 

 but saw them in the act of moulting. (See notes under Jar C.) 

 As I have never found an adult, with or without eggs, in a nest, 

 I think there can be no doubt that the casting or moulting nests 

 are built by single immature individuals for a safe retreat during 

 moulting and not by the parent for the entire brood. Mr. 

 Banks has this statement in his paper (III) which corresponds 

 exactly with my observations: "Many were young and had 

 formed little cases of silk and earth in which to pass the moulting 

 period." This was reported by Mr. Hubbard for Garypiis 

 hicornis, Bks., which lives between the laminae of rocks at 

 Specimen Ridge, Yellow Stone National Park. 



