152 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



small, rounded, brown tubercles. Below these tubercles, on the dorsum 

 is a small, rounded, frosted area. 



About half way between this area and the base of the segment, is a large, 

 sharp, claw-like, dark spine; at the base of this is a smaller, dark spine with 

 two points at the apex. Between these spines and the segmental line is 

 another sharp spine, near the base of which is a small, rounded, roughened, 

 dark spot, which is the remains of the large posterior spiracle. 



On the ventral side of the last segment are two very large tubercles, 

 semi-transparent and darkened on the inner edge to the apex. 



The under side of the thorax has two short, robust, claw-like spines, 

 bifurcated at the apex and each having a short yellow spine, near the 

 middle of the inner side. These spines are yellow with a reddish-brown 

 edge. 



On the side of all the segments, except the last, and close to the cephalic 

 edge, is a reniform spiracle, it is like the humeral one except the curved side 

 is on the opposite side. 



The adult emerges through a longitudinal, dorsal slit, in the thorax and 

 bursting of the sutures of the head. 



Criorhina (Somula) decora Macq. 

 Dipt. Exot., Suppl. II, p. 57. 



The larvae 1 of this species were taken from a pocket in a living 

 Tulip tree, by the writer, at Falls Church, Va., November 29, 

 1912. This pocket was rilled with black frass, composed of dead 

 vegetation and moistened with rain water and sap from the tree. 

 Pupation took place in the larval skin, from April 8, to 18, 1913. 

 The adults emerged from April 17 to May 1, 1913. All emerged 

 during the night. 



Egg. 



On May 13, 1915, a female of this spe'cies was observed during 

 oviposition. There was a large living tree with a small pocket 

 near the ground, which was filled with frass composed of decayed 

 leaves, etc., and rather moist with the sap. The fly flew around 

 this tree several times, making a loud humming sound, and then 

 alighted on the moist frass. After walking around on this frass 

 for a few seconds, with the abdomen moving up and down, the 

 fly stood still for a few seconds, with the tip of the abdomen touch- 

 ing the frass. Suddenly a tiny white egg appeared. This per- 

 formance was repeated before the disposition of each egg and 



1 Twice during the winter these larvae were frozen. Ordinarily they 

 are opaque but when frozen they were transparent and colorless. Shortly 

 after thawing, and returning to the opaque, all 14 larvae pupated. From 

 these 13 adults emerged. 



