4 PROCEEDINGS OF THE NATIONAL, MUSEUM. vol.60. 



BATHYMETIS UNICINCTA (Ashmead). 



Hahromma nigrum Ashmead, Proc. Wash. Acad. Sci., vol. 4, 1902, p. 188 



(not Bachia nigra Ashmead, 1899), male. 

 Isochresta unicincta Ashmead, Proc. Wash. Acad. Sci., vol. 4, 1902, p. 190, 



male. 



ALLOCOTA THYRIDOPTERIGIS Riley. 



Synonym. — Phobetus albinopennis Davis. 

 The type of albinopennis is the male of thyridopterigis. 



(HEMITELES) ZAMICROTORiDEA SYRPHICGLA (Ashmead). 



Synonym. — Zamicrotoridea orbiformis Viereck. 



AMYDRAULAX, new genus. 



Genotype. — Amydraulax pulchra.^ new species. 



In Foerster's key to the Hemiteloidae this anomalous genus runs 

 directly to Rhadinocera^ one of that author's atypic genera, to which 

 I would also run the supposed genotype of Isadelphus^ Hemitele^ 

 inimicus Gravenhorst, except for its rather short flagellar joints. 

 That inimicus belongs to the present genus I do not believe, but the 

 two have much in common — the clypeus is of the same character, 

 being laterally impressed on each side of the middle at apex with the 

 median portion very slightly emarginate so that the clypeus appears 

 to be obscurely bidentate ; the eyes are rather short, leaving a long 

 malar space, and with the antennae placed much below the middle of 

 the eyes; the venation is nearly identical except that in the present 

 genus the second intercubitus is broadly bullated, while in iniiyiicus 

 the second intercubitus is entirely lacking, and the bulla of the second 

 recurrent is entire; the form of the p^bdomen is very similar, the 

 first tergite broad with the spiracles just behind the middle, and the 

 apex strongly compressed; the appendages in the present genus are 

 long and, especially the antennae, very slender, but the relative length 

 of the joints is about the same; the sculpture of the mesoscutum and 

 abdomen is the same in both, very finely granulate. 



Among the more striking characters by which Amydraulax differs 

 from inimicus are the more strongly transverse, unswollen head ; the 

 obsolete sternauli; the incompletely areolated propodeum; the very 

 slender antennae and tarsi ; and longer and more slender ovipositor. 

 In the last character it is exceeded by Hemiteles nigriventris Thomson 

 and Isadelphus extensor Cushman. It is perhaps significant that the 

 genotype runs to a genus the name of which refers to the slender 

 antennae; and it may really be Rh(tdinoce7'a, but since Viereck* has 

 alread}'^ included an apparentl}^ quite different insect in that genus 

 it seems inadvisable to refer the present species to it. 



* Hym. Connecticut, 1917, p. 340. 



