KEVISION OF STREPSIPTERA PIERCE. 113 



From Nassonow's figuVe of the female the following description 

 may be deduced: Cephalothorax abruptly angled at the metastig- 

 mata, thence rapidly narrowed to the apex, with a very short trun- 

 cation. Head not equal in width to one-third the distance between 

 the metastigmatal angles. Mandibles, obtuse, rounded, and ap- 

 proximate to the edge of the head. Stigmata not visible on the 

 lateral edge. A dark segment of a circle lies ventrally against the 

 posterior edge of the cephalothorax (Nassonow, 1893 a, pi. 1, figs. 

 11, 12). 



Triungulinid : The body is elongate, only slightly tapering apically. 

 Head semicircular. Eye patches showing three small lenses ven- 

 trally. Thorax only slightly broader than head. Legs four-jointed, 

 (coxa, femur, tibia, tarsus) ; tarsi long, acute. Abdominal segments, 

 each with a light fringe of hairs. Tenth segment subacute with two 

 ventral tubercles, from each of which arises a long stylet equal to 

 about seven segments of the abdomen. 



4. Family HYLECHTHRIDyE Pierce, 1908. 



Hymenopterobise (part) Saunders, 1872. 

 Stylopides (part) Saunders, 1872. 



Antennae five-jointed, with fourth joint very short, and fifth elongate. 

 The family includes the one genus Hylechthrus Saunders, parasitic 

 on Prosopis in Europe. 



8. Genus HYLECHTHRUS Saunders (18SO). 

 Hylechthrus Saunders, 1872. — Pierce 1908. 



Type of genus. — HylechtJirus rubi Saunders, 1850. 



Named from Hylxus + kydpbs (enemy), meaning a parasite of the 

 genus Hylxus or Prosopis. 



The following description is taken from that published by Saunders. 



Antennae 5-jointed; basal joint short; second small, truncate; 

 third laterally produced in a very long flat process; fourth very small, 

 annulate; fifth elongate, similar to the process of the third and 

 resting against that. Maxillae small, broader than palpi, with apex 

 obliquely truncate; palpi slender, setose. a 



The remainder of the description given by Saunders is merely of 

 specific value and will be added to the description of H. rubi, as it is 

 evidently based on that species, which, as the type of the genus, is 

 the basis of comparison for the other species of the genus and the 

 only one adequately figured. 



"Antennae 5-articulata?; articulo basali brevi; secundo parvo, truncato; tertio lons-is- 

 simo, spatulato, tota fere latitudine subaequali, quartumque basin versus latere 

 externo ferenti, hoc parvo, annuloso; extimo (5-to) tertio simillimo, et ilium recum- 

 benti. Palpi parvi, articulo basali crassior, apice obliquo; apicali graciliori, setoso 

 (Saunders, 1850). 



