[Footnote 51: I have never been able to meet with an English specimen of the nest of _Atypus_; but it would appear from the descriptions that the English differ from the French nests in being subterranean, and in having the mouth of the tube concealed by a loose flap of silk. Mr. Blackwall says: [Spiders of Great Britain and Ireland, part i. p. 14] "Dr. Leech has taken specimens of _Atypus Sulzeri_ in the vicinity of London and Exeter. It excavates, in humid situations, a subterraneous gallery, which is at first horizontal, but inclines downwards towards its termination. In this gallery it spins a tube of white silk, of a compact texture, about half inch in diameter.... Part of the tube hangs outside of the aperture to protect the entrance." It would be interesting to learn whether these differences permanently distinguish the English from the French nests, and if so, whether the spiders which construct them are not, as Prof. Ausserer is inclined to believe, distinct also.] Four types of trap-door nest, properly so called, may now be distinguished in the world at large, and these are represented diagrammatically in the following woodcut.[52] [Footnote 52: Where all the figures, except C 1, and D 1, which are of the natural size, are reduced to about one-third of the actual size in large specimens.] Of these two only (A and B) were known up to the present time, the construction of which is much simpler than that of the two new types (C and D), which I have hitherto only found at Mentone and Cannes.[53] [Footnote 53: It must not be supposed that I have a sole or prior claim to what may prove to be new and of interest in the following observations on the Trap-door Spiders of the Riviera. This priority belongs to the Hon. Mrs. Richard Boyle, to whom I owe it that I ever took up the subject. It was, thanks to her guidance, that I first became acquainted with these marvellously-concealed nests in their native haunts, and to her active help that I finally arrived at a comprehension of the different types of structure which they present.] [Illustration] It will be seen at a glance that A and B have but one door, while C and D have two, these latter having a surface door, and also another door a short way under ground. All the nests consist of a tube excavated in the earth to a greater or less depth, unbranched in all but D, and in every case lined with silk, this lining being continuous with the lining of the door or doors of which it forms the hinge. I have found it convenient to distinguish these four types of nests by the following names:--A, the single door cork nest, or shortly the cork nest; B, the single door wafer nest; C, the double door unbranched nest; and D, the double door branched nest.