Xylonomus of Gravenhorst is distinguished from Xorides of 

 Latreille by the abdomen being broader at its base, and sca- 

 brous instead of smooth. 



The Xylonomi are so called from their inhabiting wood, 

 and like most others that reside in timber in the larva state 

 they vary greatly in size in the same species. In fine weather 

 the females run over the surface of paling and trees perforated 

 by bees and other insects, and investigate the holes with their 

 antennae in order to ascertain if they contain any larvae; but 

 I have never seen this rare insect deposit its eggs. 



Gravenhorst neither mentions the singular base of the tibiae 

 in the females, nor the curious spines towards the apex of their 

 antennae, which in the only male I have examined are nearly 

 straight, filiform, and very pilose on the underside. 



Two species appear to inhabit Britain, neither of which 

 has been figured. 



1. X. pilicornis Grav. — Curt. Brit. E71t.pl. 353. fern. 



Male black, slightly pubescent, head sparingly, thorax very 

 thickly punctured; postscutel rugose : abdomen rugose, smooth 

 towards the apex, 2nd and 3rd joints rufous : stigma and ner- 

 vures piceous, the former white at the base : palpi pale fus- 

 cous ; anterior legs ochreous, posterior rufous ; trochanters, 

 coxae and base of thighs black, hinder tibiae and tarsi brown, 

 the former subochreous at the base and tip. Female with the 

 12th and 3 following joints of the antennae whitish: abdomen 

 rufous, blackish at the apex : ovipositor longer than the body, 

 black, oviduct rufous : legs rufous, trochanters and coxae black, 

 4 anterior legs variegated with fuscous, hinder tibiae and all 

 the tarsi brown. 



I first discovered a male of this insect many years since in 

 Coomb-wood, on the 8th of June, and I took a female the 

 20th of last May on a rail near Hampstead. The fine female 

 figured (which is much larger than mine) was taken by my 

 friend Mr. Davis, I believe near Gravesend. 



2. X. Gravenhorstii Curtis. 



Male undiscovered. Female 4 lines long, aculeus 2 lines. 

 Distinguished from the last by its short antennas and ovipo- 

 sitor, and by its more slender form ; the base and tip only of 

 the abdomen are black ; it is smooth, not rugose, and the lon- 

 gitudinal lines at the base are scarcely visible. 



I have taken two females of this nondescript near London, 

 and have dedicated it to the distinguished Professor whose 

 elaborate work has enabled me to study this curious and ex- 

 tensive family, of which I possess upwards of 400 British 

 species. 



The plant is Briza minor (Small Quake-grass), found near 

 Poole, Dorsetshire, by the Hon. C. A. Harris. 



