50 THE CANADIAN ENTOMOLOGIST. 



these larVc'E were readily distinguished from their vigorous brethren in 

 many particulars, such as size, color and markings. And, further, that in 

 some cases growth was delayed, and even the time of moulting more than 

 doubled ; while, in others, either the first or second moulting was entirely 

 dispensed with. An examination of their chrysalids reveals the startling 

 fact that out of some twenty in my possession, all, with two exceptions, 

 are masculine in character. 



The question is often asked — Are there any checks to the undue mul- 

 tiplication of cecropia in the shape of natural enemies ? I answer in the 

 affirmative. Certain species of aves prey upon them. But no enemies 

 are more destructive than two of our commonest species of spiders, 

 Tegenaria medicitialis and Ageleiia iicevia, the former of which constructs 

 its web upon bushes of the red currant, using a curled leaf for a tube. I 

 have noticed the above species on numerous occasions engaged in drag- 

 ging caterpillars into its dens. It is only while the caterpillars are 

 young, before the first moulting has taken place, that these attacks are 

 ventured upon. Derniestes lardariiis, in the larval state, frequently attacks 

 the living chrysalis when divested of its cocoon, and does not cease from 

 its ravages until it has reduced it to a mere hull. Even the chitinous 

 covering shares the fate of the softer parts within. In a few instances, 

 these larvae had penetrated the only door of entrance, by gnawing their 

 way through the comparatively loose fibres of silk which occupy the centre 

 of the basal extremity. Their presence was only detected by the removal 

 of the cocoon. Several cocoons which I have in a warm room have 

 recently yielded fine specimens of the following parasites : Ophion macru- 

 rwn Linn., Exorista militaris Walsh, Chalcis maria Riley, and Cryptic s 

 nuncms Say — the extrematis of Cresson. At least one out of every three 

 which I raised during the past season, and the number was not short of 

 two hundred specimens, has been infested. 



The Naturalists' Directory. — This pamphlet, recently issued, will 

 prove a great convenience to all those interested in science. It contains 

 the names of Naturalists, Chemists, Physicists, and Meteorologists, 

 arranged alphabetically, the several departments separately indexed. It 

 is well printed and interleaved with blank paper, on which additional 

 names may be written. It is published by the Naturalists' Agency, 

 Salem, Mass. 



