— 109 — 



Descriptions of some New Trap-Door Spiders; Their 

 Notes and Food habits. 



By Geo. F. Atkinson. 



A few months after sending the manuscript of the article, "A new 

 trap-door 1 spider", to the publishers, I found a specimen which differed 

 so markedly in color from the one, the subject of that article, and agreed 

 so closely with the one described by Hentz as Mygale carolinensis, 2 now 

 Pachylomerus carlinensis, 3 Hentz, that before having an opportunity to 

 study them carefully I concluded the only difference was in color. Just 

 after the article, "A family of young trap-door spiders", 4 was in type I 

 discovered that the two forms were different species; that the one called 

 in the Amer, Nat. "Anew trap door spider", and the young spiders 

 whose work is described in the Ento. Am. were both new species: the 

 former I have called Pachylomerus caribivorus, and the latter Pachylome- 

 rus ^..spinosus. 



The nests of P. carib.vorus, and P. 4-spinosus, have already been de- 

 scribed in the arcticles referred to. One thing however, in regard to P. 

 caribivorus is worth adding. The last trap-door made by this species as 

 described in the Am Nat. p. 590, was in sharp contrast, being made al- 

 most entirely of clay, with the surrounding moss. In a few days the 

 spider made an examination of its work and found it had made a mis- 

 take in not placing moss in the door. It remedied this as well as pos- 

 sible by cementing moss to the edge of the door and pressing the ends 

 down so that about half of the door was covered with moss! 



Nest of Pachylomerus /urn's. March, 5, '86, on turning over an 

 old log, a sudden movement of an object downward attracted my atten- 

 tion, I looked and discovered a silken tube, with particles of earth and 

 leaf mould attached extending above ground. On one side the silk was 

 so extremely thin as to afford a "window" to the spider's house! It was 

 through this that I had discovered the movement which attracted my at- 

 tention. Nearly the entire remaining portion of the tube was covered 

 with earth and leaf-mould, and here the silk was thinner than in other 

 portions, yet intact. It seems almost incredible, yet from the wonderful 

 intelligence manifested by these spiders, I was led to think this "window" 

 had been purposely made: that the spider would sit by it and watch for 

 beetles crawling about under the log, and seeing one would rush out 



1 American Naturalist, Vol. XX, p. 583, July 1886. 



2 The Spiders of the United States, by Nicholas Marcellus Hentz, M. D., Boston 

 Journal, IV, p. 56. pi. VII, fig. 3. 



:1 Beitr&ge zur Kenntniss der Territelariae, Ausserer, p. 147. 

 * Entomologica Americana, August 1S86. 



