56 AMERICAN SPIDERS AND THEIR SPINNINGWORK, 
was suspended by a loose band of darker colored coarser silk, seven milli- 
metres long, and from the end of this band a few threads reached to the 
bottom, twenty-seven millimetres, and sides of the vial. The abdomen of 
the spider was reduced to the merest fragment, but the cephalothorax and 
legs remained. May 25th the adult issued from one end of the cocoon. 
The cocoon of P. dictyne mentioned above was about the same size and 
had a smaller supporting band, but was composed of white silk, and was 
much more delicate, nearly transparent.! 
The beautiful Argiope argentata may be added to the list of spiders 
whose cocoons are parasitized. Dr, A. Davidson sent me from Los Angeles, 
California, a fine large cocoon, which upon opening the box I 
Parasite found to be occupied by a numerous brood of small black Ich- 
pega neumonids, which proved to be a species of Eupelmus.? It is 
naan jet black, glossy, with a metallic lustre. The female is much 
larger and stouter than the male. These insects were domiciled 
within the yellow floss which pads the interior of the cocoon, and had 
probably been reared from naked pups, as no pupal cases were found. 
Several dead pup in at least two stages of development, a number of 
infertile spider eggs, and a quantity of castings and disjecta membra of the 
pup were strung throughout the padding surrounding the central cavity 
in which the Ichneumons were congregated. Among these interlopers, or 
crawling upon the surrounding fibres, were a few (six or eight) living spi- 
derlings, the feeble remainder of the original colony. These as well as the 
parasites were probably hatched en route from California in the mail bag. 
Dr. Davidson took the spider cocoon on Catalina Island, California, where 
the species is abundant. It spins its webs in cacti, and the cocoons are 
always placed some distance from and behind the snare (‘around 
Argen- the corner, as it were”), upon one of the plants to which the 
tata Co- : P Teen 
apie: foundation lines are attached. The cocoons are never hung upon 
the orb as with the specimen spun for me in captivity, and de- 
scribed Vol. II., page 84. The same gentleman remarks that the cocoons 
so closely resemble in coloring the cactus as to make them almost difficult 
to find; and he thinks it an example of concealment by mimicry of colors. 
However, cocoons of the species received from various parts of California 
have the same general hues, yellow, with more or less green,® quite regard- 
less of their situation. In the above case the “ protective” resemblance did 
not protect, as appeared from the vigorous brood of invading Ichneumonids.* 
1 Howard: “The Hymenopterous Parasites of Spiders,” Proceed. Entom. Soc., Washing- 
ton, Vol. II., No. 3. 
* Eupelmus piceus. Described by Mr. L. O. Howard. 
’ See Examples, Vol. II., pl. iv. 
4 Mr. Howard expresses the opinion, through a letter to Mr. E. T Cresson, that although 
many species of Eupelmus are egg parasites, still others are hyperparasitic; and judging 
from the size of the above species he thinks that it is probably a parasite upon some Pimpla 
which was the primary parasite in the spider cocoon. 
