either directly in an ants nest or in cK)se proxi:nity to it. I think in 

 some cases it is intended that the m.iin tube shall be used as a passage 

 for ants, so that by coming out of the branch the spider can capture its 

 food, for it is certam in these which I have observed that the external 

 door is either wanting or old and in a neglected condition, while the 

 door at the branch is kept well repaired. If I am correct in this conclu- 

 sion it would account for the apparent variation noticed in the kind of 

 nest built by this species. In the nest represented in fig. i6, Plate V, 

 the entrance <5, and the landing a, a, of the ants nest answers for the 

 main tube of the spider, and only the one tube and trap-door is required 

 for the use of the spider.^ 



1 Note. — There evidently is quite a variation, even with the same species, in 

 the kind of a nest which trap-door spiders make, As these prove to be very intelh- 

 gent creatures, I believe they vary in the construction of the nest as the conditions of 

 their environment varies, and that they adopt that plan which provides for them the 

 safest abode, and at the same time will serve them the best as a trap. At the same 

 time we must not lose sight of a common type, which, with some useful variations. 

 each species follows; though .species of uifterent genera may make the same kind nt 

 a nest, and be identical in food habit, species of the same L;enus may vary with re- 

 gard to the common type; so that the use of nests, and food habits, becomes of les- 

 value than has been heretofore supposed by some for purposes of classification. 



Mr. Moggridge says, "H. A. andT. D. Spiders" Supplement, pp. 236, and 237; 

 t.ie ran j;e and distribution of a species largely depend upon the nature of its food, 

 and this will also be an indication of the rivals etc. —"and in many cases even the 

 structure and position oiiis dwelling place will be governed by this same all — import- 

 ant question of food supply." 



Rev. O. P. Cambridge, at that lime came to this conclusion, "and in the present 

 case it is very important, as well as interesting, to conclude with some certainty that 

 differences of type in the tubular nests of the spiders Mr. Moggridge has observed so 

 closely and accurately, are joined to well marked specific differences etc. "Harvest- 

 ing Ants and Trap-Door Spiders, Supplement, p. 301". Later, Cambridge doubts 

 such close union of specific character and architectural habit, for he finds nestsof ^ii/- 

 pus piceus varying greatly in construction. (Annals of Nat. Hist. 1878, 5th series, 

 Vol.1, p. 107.) From nests made in captivity, I know that Pachylmnerus turris 

 and Nidivalvata mvjustaia make different nests accordin;^ as the environments 

 change. 



(To be continued. ) 



A monograph of the species of the subfamilies Eucneminae, Cerophyti- 

 nae and Perothopinae inhabiting the United States. By George H. Horn, INI.D. 

 Tr. Am. Ent. Soc. xiii p. 58. February 1S86. 



The species in these groups are mostly rare, and are very generally 

 wrongly named in collections. The present paper is therefore very time- 

 ly since it not only calls attention to the insects, but enables students to 

 straighten out their material. It would be interesting to discover some- 

 thing of the habits of these species. Most of them are accidental finds and 

 no one knows exactly where to look for them with any certainty of success. 



