l895-] ENTOMOLOGICAL NEWS. 253 



dense than that of the remainder of the cell and the interval 

 between is an open meshwork of fibres. Whether or not this 

 is to be considered as an air hole or breathing tube, it is doubt- 

 less analogous to the structures described by Prof. Riley as 

 occurring in the Sphecius speciosus{'' Insect Life " vol. iv, 252). 



Its capability to supply air must, from the nature of the inte- 

 rior lining, be limited indeed, yet probably this is its purpose. 

 The remainder of the cell with its surfaces polished externally 

 and internally seems totally impervious to air. Why the air- 

 holes in the cocoon of Sphecius speciosus should be made to pro- 

 ject above the surface I do not understand, but the necessity of 

 their so doing in this instance is apparent on superficial examina- 

 tion. As I have already observed, the cocoons are covered 

 over with a layer of excrementitious matter, so that unless the 

 air-hole projected above the surface it too would become cemented 

 over in the process of spinning the cocoon. The air-hole is 

 always on the end nearest the outlet, and the larva always lies 

 with its head toward that end. 



Oi the forty specimens of cells in my collection that appear on 

 superficial examination to be identical, and were presumably 

 built by this Anthidium, five prove to be constructed by an 

 Anthidhim of a larger size and brighter color than the one under 

 review. Among the remainder were seven cells of the typical 

 shape, but of smaller size, and thicker walled, the increased 

 thickness being due to another layer uniformly disposed inter- 

 nally and forming in reality a double walled cocoon the interior 

 of which was less glossy than the type.* These larvae on hatching 

 proved to be of an entirely different species, and have been 

 identified for me (doubtfully, I fear) as Megachile brevis, Say. 



Nine of the cells were occupied by parasites Of these 



Leucospis affinis occupied three. 



Phoiopsis unicolor Cress, occupied three. 



SphiBrophthalma sp.? occupied one. 



Monodontomerus montivagus Ashm. occupied one. 



Physocephalus affinis. Will, occupied one. 



This last was found in the cell adjoining that which contained 

 the Sphcerophthabna both of which were discovered in a nest 

 constructed in the empty retreat of a trap-door spider. 



* This species build their nests in June and July, and after spinning their cocoons remain 

 in the larval state throughout the Winter, pupating shortly belore making their exit in 

 the first week of June. 



