June 1894.] ZaBRISK IK. PARASITES OF VeSI'A, 83 



hence the species was nut delerminecl, but it is pi-ol)al)lc that tliey 

 both were of Vespa gcrmaiiica Fab. 



The first nest was six inches in t-\treme dianuter; contained 

 three tiers of combs; and liibenialinn- within it were 159 living 

 specimens of our common l)rown wasp, Po/isds inctiicus Say. The 

 second nest was eiglu inches in diameter, with four tiers of combs, 

 and within were 169 liviiiL]^ siK'cimens of /'fV/V/« ///(V/vVz/y and eleven 

 large Hies. 



In the cells of these nests were found living specimens of two 

 hymenopterous parasites, of widely separated genera, and the 

 cocoons of a third hymenopterous parasite, which had issued before 

 examination was made. 



'I'he first parasite. In the bottom of some of the vespa cells, 

 whiih were always open at the lower extremity or entrance, and 

 which evidently had been cleaned out by the workers to this 

 region, was observed a firm, smooth, yellow floor; entirely filling 

 this portion of the vespa cell ; firndy adhering to its hexagonal 

 walls; about one-third of the diameter of this lloor being occupied 

 with a central, circular, translucent film ; this film affording an 

 easy point of exit for the occupant of the otherwise hard mass; 

 and 1 he plane of the tloor or ontcr surface of the \ellow mass 

 always lying at an angh' of nrarlv 45^' with the axis of the vespa 

 cell.' (Fig. 2.) 



There were 16 of these yellow masses in. the first nest. On 

 extracting one of them it was found to be the cocoon of a hymen- 

 opterous parasite; entirely filling the inner portion of the vespa 

 cell for about one-third of its dei)th ; so closelv adhering to the 

 walls of the latter that they could not be separated without tearing, 

 and of such unusually hard structure, especially at the outer 

 incliiucl surface, as to be almost like wood under the knife. The 

 hard yellow walls of these cocoons were formed of a coarse fibred 

 silk, ilispo=;ed in concentric sheets, slightly separated in the thicker 

 portions of the walls, reminding one of the concentric envelopes 

 of the vespa nest. The cavity of the cocoons was occupied by a 

 closely fitting but easily detachable case, composed of three or 

 four concentric layers of a transjiarent yellowish substance, like 

 the most delicate mica, but showing no fibrous structure under 

 high magnification. In several instances two of these parasitic 

 cocoons were placed one directly upon the other in one vespa cell. 

 In the first nest were fouiul i6, and in the secoiul nearl)- loo of 

 these vellow cocoons. On dissecting one of these cocoons a 



