ELISHA MITCHELL SCIENTIFIC SOCIETY. 43 



DESCRIPTIONS. 



Prefatory Note. It is not surprising that in a collection 

 of some forty specimens there would be found several 

 species, nor that a large number of these would prove to be 

 new and undescribed forms, where so little attention has 

 been given to spiders in general, and especially those of the 

 order Territelarice, as has been given in America. 



It has been a great pleasure to me to observe the nests 

 and habits of so many of these creatures, which by their 

 solitary and secluded life generally escape our observation. 

 It has seemed necessary, that, in connection with interesting 

 descriptions of their nests, architectural and food habits, 

 these forms should be described and named. So interested 

 have I become during the past year in the work of N. M. 

 Hentz, that it would have given me more pleasure to find a 

 specimen described by him than to find a new form. I feel 

 sure that I have found one of his species, and possibly one 

 other related species. I undertook the work of description 

 with great reluctance, and have found it to be no small task. 

 But my labors have been greatly lessened and I have been 

 sensibly encouraged by the kindness of Dr. George Marx, of 

 Washington, Prof J. H. Emerton and Samuel Henshaw, of 

 Boston. Dr, Marx loaned me works from his private library, 

 Prof Emerton placed for my study his excellent collection 

 of Arachnological publications, and specimens for compari- 

 son, which are now in the Mass. Inst. Tech., and showed me 

 further kindness in directing me to the most useful works in 

 the Library of the Boston Natural History Society. Mr. 

 Henshaw also aided me in the same way and gave me the 

 use of the specimens of Territelarice which are in the Museum 

 of the Society. 



I have also found works in the Boston Public Library 

 which have aided me. 



In the value of generic and specific characters I have been 



the present case it is very important, as well as interesting, to conclude 

 with som certainty that differences of type in the tubular ne^ts of the 

 spiders Mr. Mcgti ridge has observed so closely and accurately, are joined 

 to Well marked specific differences etc. "Harvesting Ants and Trap- 

 Door Spiders, Supplement p 301." Later, Cambridge doubts such close 

 union of specific character and architectural habit, for he finds nests of 

 Atypufi piceus varying greatly in construction. (Annals of Nat. Hist. 

 1878, 5th series, Vol. 1, p. 107.) From nests made in captivity, I know 

 that Pachyhmerus hirris 'and Nidivalvnta anguslata make different nests 

 according as the environments change. 



