350 



Antennal sheaths distinctly annulated, the anterior basal surface 

 of each with a stout thorn (PI. L, Fig. 6) ; entire aspect of head and 

 mouth parts as in figure just mentioned; dorsal surface of head- 

 capsule with 3 small punctiform depressions on ocellar region and on 

 each side a single hair ; suture between cephalic and thoracic segments 

 deep, the posterior margin of the former with short longitudinal im- 

 pressed lines. Thoracic spiracle much elevated, in the form of a short 

 stout tubercle, the apical opening small, somewhat 8-shaped ; protho- 

 rax with a transverse discal, linear series of small closely placed round 

 depressions ; mesothorax with 2 faintly indicated sutures and 2 rather 

 large poorly defined depressions, one behind the other, above wing- 

 base; wings without discal protuberances, their apices rather widely 

 separated, extending distinctly beyond apices of fore tarsi ; apices of 

 mid and hind tarsi curved towards median line, the latter extending 

 little beyond apices of wing. Abdominal spiracles similar in form to 

 those of thorax but not so much elevated ; first dorsal abdominal seg- 

 ment with 4 weak, widely separated hairs on disc near posterior mar- 

 gin, the median pair much closer to each other than they are to the 

 lateral hairs; lateral areas with 4-6 hairs; segments 2—7 each with a 

 transverse post-median series of closely placed hairs which become 

 progressively slightly stronger from i to 7; eighth segment with 4-5 

 spines on each side of disc in a transverse series ; postspiracular area 

 of first segment with 7—8 strong bristles ; ventral segments similar in 

 armature to dorsal; apical segment of female as in Figure 2, Plate L. 



Larvae of this species were common under bark of a felled elm 

 at White Heath, 111., March 12, 1916. Several specimens pupated 

 from 3 to 5 days after being brought to the laboratory, and the first 

 imago emerged on March 22, others appearing on the 25th and 26th. 



When collecting the larvae I also captured several larvae of 

 Saperda tridentata, and others of Meracantha contracta (Coleoptera), 

 which I brought in to ascertain whether the xylophagid would eat 

 either of them. One of the Meracantha larvae was eaten, the entire 

 contents being extracted through a hole made in the skin; but the 

 Saperda was not attacked. It is very probable that the food of the 

 xylophagid does not consist wholly of the larvae of Meracantha as 

 this species was rarely met with in company with the larvae of the fly, 

 and probably Saperda is also eaten. 



The logs in w^iich I found the larvae were second-year lumber on 

 which the bark was not very loose. When the borings of other in- 

 sects have thoroughly loosened the bark, conditions are apparently not 

 suitable for the larvae, as none were found in such logs. 



