1909.] NATURAL SCIENCES OF PHILADELPHIA. 567 



base on to and across the egg mass, with swinging of the abdomen from 

 side to side; the remainder of the time in brushing the spinnerets to 

 and fro without raising them, which resulted in the dense structure of 

 the outer surface of the cover. Next morning the cocoon was partly 

 covered with small debris (bits of earth and wood, fragments of in- 

 sects), and rendered much less conspicuous. The free surface of the 

 cocoon is always furnished in this manner; it is never enclosed in a nest, 

 and the mother does not remain by it. The cocoon is not only par- 

 tiall} r hidden in this way, but it is so closely adherent, so flattened and 

 so tough, that the eggs are most excellently protected, and this explains 

 why so few eggs are laid. Two cocoons were found with 8 eggs each, 

 and three with 9. The method of applying the foreign objects to the 

 cocoon was seen clearly in the case of two cocoons made by other 

 females during the night of 26 July, some time between 10.30 P.M. 

 and 7.30 A.M. These cocoons were placed only an inch apart, the 

 mothers did not seem to distinguish their own from the other's, and 

 proceeded to furnish either impartially. Each mother hunted around 

 the cage by touch, for small objects, carried them in the chelicera to a 

 cocoon, also found by touch (though there appeared to be some memory 

 of its situation), then dropped them upon a cocoon. Then the mothers 

 chewed these objects into smaller particles, and agglutinated them to 

 the cocoon evidently by some salivary secretion, and to this secretion 

 is also probably due the change in color of the cocoon surface from a 

 beautiful opaline, or pearly, lustre to a dull brown. 



So far as I know this is the first instance described of the application 

 of some salivary secretion to the cocoon surface; very likely the bluish 

 or greenish colors of the outer layer of Lycosid cocoons are also due to 

 a similar secretion from the mouth, for the silk employed is white, 

 and the cocoon does not change its white color until the mother holds 

 it beneath her and carefully applies her mouth parts to all of its surface. 

 This secretion may have the value of a varnish, a finish smoothing 

 over all irregularities. 



Phrurolithus alarius (Hentz). 



As Emerton (1889) notes, this drassid "lives on and under stones 

 in dry, open ground and runs with great swiftness short distances at 

 a time/' The spiders are much less frequently seen than their cocoons. 

 The latter are tightly fastened to stones, scarlet in color, probably 

 due to a salivary secretion, much flattened and scale-like, of greater 

 diameter than the spider's length, and are sometimes covered with 

 foreign matter. They are not guarded by the mother, and it was only 



