74 PECKHAM. [Vol. 1. 



cocoons of copliinaria, though a Httle smaller, closely resemble 

 in shape and color the oak-apple, Quercus inanis, which abounds 

 among red oaks ; but if this is a case of protective resemblance, 

 which seems improbable since cophinaria inhabits open, marshy 

 places and is not found in the woods, the disguise is far from 

 being a complete protection. Each cocoon contains many hun- 

 dreds of eggs, but among them a wholesale destruction is carried 

 on by cophinaria's most dangerous enemj^, the ichneumon fly. 

 The cocoons are hung among the long grass and are not difficult 

 to find, but when opened they so frequently contain nothing but 

 young ichneumons as to make it reasonable to believe that 

 where the enemies of other species slay their hundreds this one 

 enemy of cophinaria slays its thousands.* 



Another, and perhaps the most serious of all the dangers 

 to which this species is exposed, is the flooding of the marshy 

 land upon which the cocoons are deposited. During the pres- 

 ent spring we collected 62 cophinaria cocoons, some of which 

 were in a fragmentary condition. Of the whole number 26 

 contained live spiders, 6 contained eggs just about to hatch, 

 24 had been destroyed by parasites and 6 by water. In the 

 marsh where the full-grown spider is most abundant in 

 August, every bush being covered with them, we found only 

 three water-soaked cocoons. When they are destroyed by para- 

 sites the case remains, but when the water spoils them they are 

 probably decayed, broken up and washed away, seldom lenv- 



* Of 406 cocoons of this species taken in one spring by Prof. Wilder, 134 were 

 entire ; 190 were pierced, but contained live spiders ; 59 were torn, probably by birds, 

 most of them still containing some of the spiders, and 23 contained the remains of 

 parasites by which the young spiders, or the eggs, had been destroyed.— jdnifin'care 

 Ansuciation for Advancement of Science, Vol. xxn, p. 201. 



Prof. Wilder thinks that the young spiders devour each other to a considerable 

 extent, as they are shut up for weeks or months after they are hatched with no food 

 but one another. Young spiders, however, probably do not eat until after about the 

 second or third moult, and although those that he observed did eat each other they 

 were under unnatural conditions, and must have grown less rapidly and remained 

 longer in the cocoon than they would had they been left out of doors, as even with 

 our late Wisconsin spring we find the young of copliinaria running about, half grown, 

 in June. 



The eggs of this species are also open to the attacks of another spider 

 Eraerton has found the young of P. m.orsitans in cocoons of cophinaria (Note 

 Hentz's Spirlers of Korlli America, p. 58.) 



