SUBFAMILY I. TRYXALIX.E. 217 



a six-plank fence. The abdomen was curved downward, and the 

 toothed forcipate valves of the ovipositor used as pincers with 

 which small pieces of wood were broken off. When discovered 

 the abdomen was inserted nearly one-half an inch in the pine 

 board, and the upper edge of the opening about the sides of the 

 abdomen was covered with small pieces of the wood, just as the 

 dust or borings will accumulate about the edge of a hole which a 

 carpenter is boring. I stood by and watched her work for ten or 

 more minutes, when she suddenly stopped, withdrew her ovipos- 

 itor and hopped away. Along the fence, within a distance of 30 

 feet, I found 15 other holes, 11 of which were fresh, while the 

 others had evidently been bored the previous year. Most of these 

 holes were on the upper edge of the top board, which was in all 

 cases of pine and perfectly sound. None of the holes contained 

 eggs, most of them being less than half an inch in depth. On July 

 21st, and September 21st, I have found them with the abdomen 

 inserted full length in stumps or logs, and when removed, eggs 

 were found in the lower horizontal portion of each cavity. On 

 the former date the female was ovipositing after dark in an oak 

 log which served as part of a bridge across a stream. Smith 

 (loc. cit.) has suggested that the reason for so few holes being 

 finished is that the wood proves too hard, and the insect tries 

 for a softer place, or, many of them may be disturbed during the 

 process of oviposition. 



Scudder (loc. cit.) says: 



"The wood must be firm enough to retain the eggs well in place, and 

 soft enough to absorb much moisture in the spring. Upright pieces of 

 timber are never chosen, but rather short sticks of decaying, charred or 

 pithy wood, which can not easily be broken or blown against the rocks. 

 Holes are frequently made three-quarters of an inch deep, and abandoned 

 because the spot proves unsuitable. In a stick about a foot and a half 

 long, and two or three inches wide, I counted 75 borings, only three or 

 four of which had been used as nests. The number of imperfect to per- 

 fect holes must be as 25 to one. When a good piece of wood is discov- 

 ered, the nests are crowded thickly together; and a stick less than two 

 inches in diameter and five inches in length contained 13 completed nests. 

 The holes are pierced at a slight angle to the perpendicular, away from 

 the insect; they are straight for about a quarter of an inch, then turn 

 abruptly and run horizontally along the grain for about an inch. 



The eggs (from 10 to 14 in number) are almost always laid in the 

 horizontal portion of the nest; they are cylindrical, tapering toward the 

 ends, but not at all pointed, and measure from five to five and a half mil- 

 limeters in length, by one and one-eighth in breadth; the ends are equally 

 and regularly rounded. They vary in tint, some being almost colorless, 



