Another form of this single door wafer nest is described by Mr. Sells,[57] in which there is a hinge-like thickening of the silk lining of the tube about an inch below the actual hinge of the door, which it is suggested may serve to give additional elasticity. This was not found, however, in all the nests examined, and Mr. Sells conjectures that in newly constructed nests the lid may close sufficiently firmly without this contrivance, and that it is only added in older nests. [Footnote 57: Mr. W. Sells. Notes respecting the Nest of _Cteniza nidulans_, in Trans. Ent. Soc. ii. 207-210.] Patrick Browne's figure, to which reference has been made above, represents a nest with two doors, one applied against the other, at the mouth of the tube, and it has often been asked what this could possibly mean. Some have thought that the drawing was fanciful, others that it was made from an abnormal or injured nest. However, I believe that the drawing, though rude, is, in fact, not very incorrect, and shows a case of repair or enlargement of the nest, a subject to be treated of more fully further on. There is a specimen exhibited in the British Museum which in this respect very nearly corresponds with Browne's figure; it is labelled "Nest of Trap-door Spider with two doors, from the spider having enlarged its abode.--Jamaica." Here one sees that the spider has prolonged its tube about half an inch beyond the original mouth of the nest, where it has constructed a new mouth and door, the old door standing straight up at the back of and behind the new one. I imagine that the explanation of this curious piece of cobbling may be somewhat as follows:--When the nest was in its original state and had but one door, this door became by some accident covered over with earth to about the depth of half an inch, and the inmate was thus imprisoned. Then the spider, being, like most other members of its order, very unwilling to abandon its home, determined to clear away the entrance to its nest, and to lengthen the tube so that it should reach up to the new level of the surface of the earth.... If I am right, this should rather be called a lengthening than an enlargement of the tube. The nests of the cork type (A, p. 79) may usually be distinguished at a glance from those of the wafer type by the greater thickness of the door, and by its manner of shutting, but a nest from Morocco has been figured and described by Prof. Westwood,[58] which seems intermediate between the two. The door in this case may perhaps be considered as of the cork type, though it is very thin, for it does fit into the mouth of the tube, which is bevelled to receive it. [Footnote 58: Observations on the Species of Trap-door Spiders, in Trans. of Entomological Soc., London, 1841-3, vol. iii. p. 175.