502 U. S. NATIONAL MUSEUM BULLETIN 216 



Sterolrichus Foerster, 1868, Verh. Naturh. Ver. Rheinlande, vol. 25, p. 169. 



Type: (Xylonomus pilicornis Gravenhorst) = faligator (Thunberg); designated 



by Viereck, 1914. 

 Sichelia Foerster, 1868, Verh. Naturh. Ver. Rheinlande, vol. 25, p. 169. Type: 



Xylonomus filformis Gravenhorst; designated by Viereck, 1914. 

 Rhadina Foerster, 1868, Verh. Naturh. Ver. Rheinlande, vol. 25, p. 170. Name 



preoccupied. Type: Xylonomus ater Gravenhorst; included by Schmiede- 



knecht, 1888. 

 Rhadinopimpla Schulz, 1906, Zool. Ann., vol. 4, p. 23. New name for Rhadina. 

 Xylonomimus Clement, 1938, Festschrift zum 60. Geburtstage von Professor 



Dr. Embrik Strand, vol. 4, p. 539. Type: Xylonomus gracilicornis Graven- 

 horst; original designation. 

 Neoxylonomus Clement, 1938, Festschrift zum 60. Geburtstage von Professor 



Dr. Embrik Strand, vol. 4, p. 566. Name preoccupied. Type: Neoxylonomus 



strandi Clement; monobasic. 

 Amphixylonomus Benoit, 1952, Bull. Ann. Soc. Ent. Belgique, vol. 88, p. 136. 



New synonymy. Type: Xylonomus (Amphixylonomus) kondiiensis Benoit; 



original designation. 



Body slender to moderately stout ; female flagellum with a subapical 

 curve that involves several articulations; occipital carina complete or 

 interrupted above; temple variously punctate, or wrinkled, or striate, 

 the wrinkles or striae oblique or sub vertical; tooth at upper end of 

 epomia weak to moderately strong and projecting; prepectal carina 

 present; median lobe of mesoscutum without a median longitudinal 

 groove; posterior mesosternal carina incomplete; propodeal carinae 

 more or less complete; areola subpentagonal, open or closed at the 

 base ; apex of area dentipara with or without a tooth ; nervulus beyond 

 basal vein, usually by about 0.3 its length; intercubitus about 0.4 as 

 long as second abscissa of cubitus, or shorter, or sometimes obliterated 

 by approximation of radial and cubital veins; all trochanters without 

 teeth; front tibia of female weakly to strongly inflated. 



This is a large subgenus which contains a diverse assemblage of 

 species. It is mostly Holarctic in distribution. The genotypes 

 of Xorides, Xylonom.us, Sterotrichus , and Amphixylonomus belong to 

 a species group including a number of Palaearctic species but 

 apparently none in North America. We hereby designate this group 

 as the indicatorius group. The genotype of Sichelia belongs in 

 the ma.udae group, as defined in the treatment of the Nearctic species, 

 below. The genotype of Rhadina is close to the Nearctic insularis, 

 in the insularis group. The genotype of Neoxylonomus is very similar 

 to the Nearctic boharti, in the rileyi group. The genotype of 

 Xylonomimus is unknown to us, but judging from its description, 

 it is a flattened species of the insularis group. 



The European species of the subgenus have been treated by 

 Clement (1938, Festschrift zum 60. Geburtstage von Professor Dr. 

 Embrik Strand, vol. 4, pp. 522-568). He placed the species in his 

 "genera" Xorides, Xylonomimus, Xylonomus, Sichelia, and 



