It will be seen that species belonging to the same genus, and closely resembling one another, sometimes build dissimilar nests; while others, belonging to different genera, and unlike in many important respects, construct almost identical nests.
This is the more strange, because, if we examine the structure of the claws and palpi, they often seem to be specially adapted to serve as carding instruments and to play a very important part in the weaving of the silk linings of the nest; and yet nests of the same type are occasionally produced by spiders in which these appendages are quite unlike, and dissimilar nests where the claws and palpi are to all appearance identical.
Thus, for example, if the reader will examine the drawings of part of the foremost right foot of Cteniza fodiens, figs. A, 9 and 10, Plate VII., p. 88, with that of Nemesia cæmentaria, figs. A, 9 and 10, Plate VIII., p. 94, both of which make nests of the cork type, he will see that in the former the last joint of the tarsus is armed along the inner side, with many moveable spines, and that each of the two curved terminal claws has only one very strong tooth near the base; while the same joint of the latter (N. cæmentaria) has no spines, and the claws have three minute comb-like teeth near the base.
On the other hand, in the reverse case, where the structure of the same joint is very similar, the nests may be wholly unlike, as in Nemesia Eleanora, Plate XII., p. 106, and N. cæmentaria, Plate VIII., where the nest of the former is of the double-door unbranched type, and that of the latter of the single-door cork type.
It is probable however that a fuller and closer comparison of, and a more exact acquaintance with the
