[135] ON SOME SPECIES OF Cossus. 247 



oak which had been prepared for fuel. They were both frozen 

 rigidly when discovered. One was lying in a cell, in its burrow, 

 formed by some slight threads in which its cuttings had been 

 thinly woven above and below it: the other had constructed 

 a cell of about the capacity of its body, branching off from its 

 main burrow its entrance closed by a thin wall of the cuttings. 



The smaller of the two larvae measured one inch and a half 

 in length. It was of a pale green color, with a darker green 

 dorsal stripe, bordered faintly with yellow. Head flat, sub- 

 triangular, dark brown, clouded with black. First segment 

 with two brown spots extending across it, narrowed laterally, 

 and of nearly the length of the segment medially, where they 

 unite to inclose on the dorsal line an elongate-elliptical green 

 spot. The anterior segments are flattened, and broader than 

 the following, which gradually diminish in breadth toward 

 the posterior end. The segments are marked dorsally with 

 four rose-colored elevated points the trapezoidal spots of 

 Ghienee; on the 10th and llth segments they form a square : 

 a similar spot is present above each stigma, a smaller one be- 

 low, and another in front each of these bearing a short brown 

 hair. The stigmata are oval, orange color.ed, centered with 

 dark brown. The legs are tipped with chestnut brown, and 

 the prolegs armed with brown plantse. 



One of the larvae escaped from its burrow by gnawing 

 through the stick of wood in which it was inclosed and its 

 paper box, and was found some weeks thereafter, dead within 

 a roll of clothing. The other disclosed a perfect imago on the 

 29th of April the female type of the rare C. querciperda of 

 my Collection. The larva had constructed within its burrow 

 a very slight cocoon of delicate silk. The long ovipositor of 

 the moth was a marked feature of it, when alive, measuring 

 in its full extrusion, three-tenths of an inch. It displayed a 

 tenacity of life remarkable even in a gravid Bombycid, as it 

 lived for twenty -four hours after a strong solution of cyanide 

 of potassium had been pricked in its thorax. 



The most interesting character of this species is not referred 

 to in its description, viz. : the great disparity in the size of the 

 sexes. The <$ measures in length of body 0.55 in., and in 

 expanse of wings, 1.23 in. The body of the ? , exclusive of 

 its ovipositor, is 1.25 in. long, and the expanse of wings is 

 2.62 in. Their comparative weight is as one to four, even 



