which the abdomen has not two, but twelve or fifteen humps.  These are so disposed that the edge of the abdomen, all around, is scalloped.  The colors are light and dark brown, modified by gray and white hairs.  This spider remains motionless during the daytime, keeping its legs drawn up to its body.  It is common on grass and low bushes.  It is not found in Wisconsin, but the description of it suggests a resemblance to a piece of dead leaf.

There are many other spiders in this genus that have humps and are colored in brown, gray or dull yellow, as nordmanii, angulata, solitaria, etc.  It is an almost universal habit among the Epeiridae to drop to the ground when threatened, and when a humped gray or brown spider drops to the ground and draws in its legs it is nearly indistinguishable from the lumps of earth, sticks and stones that surround it.

One of the Therididae which has the same protection is Ulesanis americana (Fig. 3).  The abdomen, which covers the cephalothorax nearly to the eyes, has a prominent hump in the middle of the back and four or five others behind.  Its color is in shades of brown and yellow.

[Illustration:  FIG. 3.—­ULESANIS AMERICANA (from Emerton).]

Analogous to the humped Epeiridae is Thomisus foka, of Madagascar, a spider which is regarded with great terror by the natives, as being so poisonous that even its breath is deadly.  They say that cattle, when about to lie down, look carefully about to see if one of these spiders is in the neighborhood.  This dread is, no doubt, inspired by the strange and uncanny aspect of a perfectly harmless creature.  It has a rugose, tuberculated body of trapezoid form, the colors being brown and reddish, while the whole aspect is crab-like.  The thick, short legs are reddish, covered with tubercules.  The secret of its strange form is made clear when we learn that it resembles in color and general appearance the fruit of Hymenaea verrucosa, a tree common in the forests where this spider is found.

Among the curious forms which must have been developed through advantageous variations but which we are unable to explain, is Eriauchenus workmanni (Fig. 4).

[Illustration:  FIG. 4.—­ERIAUCHENUS WORKMANNI (from Cambridge).]

Epeira prompta, a variety of parvula, is a common spider in the State of Wisconsin.  It is most frequently seen on cedar bushes, where its color harmonizes with that of the foliage and fruit.  During the day it usually rests on a branch near its web.  The back of the abdomen is of a peculiar bluish-green, exactly like that of the lichens growing on tree trunks.  The bluish color is broken by waving black lines which imitate the curling edges of the lichens.  The one represented in the plate was found on an old cedar which was covered with lichens.  It was kept for two weeks in a glass-covered box, where it spent most of the time crouching in a corner.  It built no web, but spun some irregular lines to run about on.  It ate gnats, flies, and once a little jumping spider, S. pulex, which we were keeping in the same box, leaping upon its prey, as noted by Hentz, like an Attus.  This seems a curious habit to be acquired by an Epeirid, since spiders, as we have noticed among our captives, are usually dependent for food upon what is caught in their webs.  Prompta moves awkwardly, but very rapidly.