136 PROC. ENT. SOC. WASH., VOL. 20, NO. 7, OCT., 1918 



* 



I had been much interested to learn how the larva makes this 

 shellac-like, transparent layer with its few strands, and had sup- 

 posed that it was composed of two kinds of secretion, a frame- 

 work of silk over which was laid a quick-drying liquid. But 

 observation of the process disclosed the fact that the silk is spun 

 in a thread, but the thread is very soft and largely semiliquid 

 so that it spreads out and coalesces with the adjacent threads, 

 while still maintaining somewhat in the center its strand-like 

 appearance. 



When first secreted the silk is colorless, gradually assuming the 

 amber tint. 



For a long time after the beginning of the inner layer the tip 

 was left open, but it was gradually closed and made thick by 

 short strokes of the head back and forth across it. In this way 

 the little cap that the adult pushes off in emerging was differen- 

 tiated from the main body of the cocoon. 



After the parasite has issued from its host the latter drops, 

 still living, to the ground, where it writhes aimlessly about until 

 death overtakes it, in many cases, twenty-four hours or more 

 later. 



A SYNOPSIS OF THE SPECIES BELONGING TO THE CHALCIDOID 

 GENUS RILEYA ASHMEAD (HYM.) 



BY A. B. GAHAN, 

 Bureau of Entomology, U. S. Department of Agriculture. 



The genus Rileya Ashmead (Ent. Amer. IV, 1888, p. 42 and 

 Bull. 3, Kans. State Agri. Coll., 1888, App. p. 3.) which has as a 

 synonym Ashmeadia Howard (Can. Ent. XXI, 1889, p. 59) is, so 

 far as known, confined in its distribution to North and South 

 America and the West Indies. All of the described species as 

 well as four new species are included in the key given below. A 

 number of the species are placed in the key from the original 

 descriptions, the types not being accessible for comparison. 

 Short descriptive notes on the species, types of which are in the 

 United States National Museum, are included. 



All of the species for which there are rearing records are appar- 

 ently parasitic in the galls of dipterous insects. 



The genus is characterized by having thirteen-jointed anten- 

 nae, the funicle five-jointed, the club three-jointed; antennae of 

 the male similar to that of the female (except in the species 

 <ibnormicornis) ; head strongly transverse ; posterior margin of 

 cheeks sharply carinate; pronotum as broad as the mesonotum 

 and approximately the same length, rounded in front; meso- 



