'8 THE CANADIAN ENTOMOLOGIST. 



flattened, scale-like objects, 10-12 mm. in diameter, adhering closely to 

 stones, and often irregular in shape to conform to the uneven surface. 

 When new, the silk of which they are spun is of a delicate drab shade, 

 but weathered cocoons found in spring are of a dull, dirty gray. A 

 single larva of the Pezomachus occupies each infested cocoon, and when 

 it has devoured all the spider's eggs it spins its own elongate cocoon 

 within that of its host. This insect must be a great check upon the 

 increase of its spider-host, for of scores of cocoons examined in one 

 locality last spring hardly ten per cent, had escaped infestation. Through 

 the kindness of Mr. L. O. Howard, one of these cocoons has been 

 examined by Mr. Nathan Banks, who pronounces it to be " almost cer- 

 tainly a Drassid cocoon, possibly Micaria, but more probably Prosthes- 

 ima." The cocoons are sometimes found on the under surfaces of stones 

 and pieces of wood, but more frequently on the upper surface of large 

 embedded rocks. 



Hemiteles ottawaensis, n. sp, 



Male, length, 5 mm. Black, with segments two and three of 

 abdomen yellowish. Head black ; palpi pale ; antennte blackish, slender, 

 about 25-jointed, scape, pedicel and base of third joint pale. Thorax 

 black, finely punctulate or shagreened ; tegulse pale ; legs rufo-testaceous, 

 including coxae; the posterior tibiae and tarsi brownish ; wings as usual, 

 stigma brown ; metathorax feebly areolate, the lateral and posterior 

 transverse carinas more distinct. Abdomen narrow, segments two and 

 three yellowish, remainder black. 



Described from one male reared from egg-cocoon of spider. The 

 cocoon was one of a lot, gathered at same time and locality, which 

 yielded several individuals of the previously described species, and the 

 Hemiteles is probably the male of that species. I have, therefore, given 

 to it the same specific name. As it differs, however, in the evident, 

 though imperfect, areolation of thorax, and in colour of abdomen, etc., it 

 may be better to separate it for the present. The abdomen is narrower 

 and less robust than that of the winged males of P. Pettitii. 



Mastocharis wilderi, Howard. 



Twenty-two examples of this little Chalcid were bred from a hemi- 

 spherical egg-cocoon of a spider, attached to the under surface of a hickory 

 leaf. They issued, however, from the cocoon of an Ichneumonid, prob- 



