REVISION OF STREPSIPTERA PIERCE. 115 



The host of this species, Prosopis rubicola Saunders, occurs in 

 Epirus. It makes its own nests as a rule, in briars, although some- 

 times they have been found to build in the unoccupied excavations 

 of Osmia, and even in the mud cells of Odynerus, and in the same 

 excavations as Cemonus unicolor. When parasitized by male Hylech- 

 thrus this species has the abdomen much lighter, so much so that 

 Saunders described this variation as Prosopis (Hylaeus) versicolor. 



2. HYLECHTHRUS QUERCUS Saunders (1850). 



Hylechthrus quercus Saunders, 1852, 1872. — Pierce, 1808. 



Host. — Prosopis gibba Saunders; Epirus, May, June. 



Saunders described this specie essentially as follows: 



Male differs from Hylechthrus rubi by its greater size, by the wings 

 being more obscured, and the veins much darker. Length §-1 line; 

 expanse of wings about If line. a 



Prosopis gibba, the host of this species, dwells in vacant cynipid 

 oak galls, and also in briars in diagonal series. (This last note is 

 based on a marginal note by Saunders in the separate possessed by 

 the author.) 



3. HYLECHTHRUS SIEBOLDII Saunders (1852). 



Hylechthrus sieboldii Saunders, 1872. — Pierce, 1908. 



Host. — Prosopis variegata Fabricius, Epirus, June. 



The cephalothorax of the female of this species is distinguished by 

 a broad yellow longitudinal band dilated toward the apex, and by 

 a dark transverse line at the base, interrupted by the passage to the 

 abdominal region. 



5. Family XENIMS Semenov, 1902; redefined Pierce, 1908. 



Strepsiptera or Stylopidx (part) Hoeven, 1850. 



Xenides (part) Saunders, 1872. 



Pseudoxenides (part) Saunders, 1872. 



Stylopinte (part) Perkins, 1905. 



Xenini Perkins, 1906 in correspondence (a tribe of Stylopinse). 



Type genus. — Xenos Rossi (1794). 

 Parasites of Hymenoptera. 



Antennae four-jointed, the third laterally produced; tarsi four- 

 jointed. 



The family is composed of four subfamilies: 



Xeninae Pierce, parasitic on Vespoidea and perhaps Sphecoidea. 



a Male. — Differt (from Hylechthrus rubi) magnitudine duplo majori, alis pariim 

 obscurioribus, venisque magis nigricantibus. 

 Long, corps, §-1 lin. Expans. alar, fere If lin. 

 Individua mutilata tantum vidi (Saunders, 1850). 



