92 COLEOPTERA. 



S. Wettey^hallii is of the same size as scutellarisy and allied 

 to hirticolliSf but with an almost smooth thorax, and only 

 the three last joints of the antennae enlarged. 



128. Triarthron Markelii, Schmidt, Ent. Zeit., 1840, 

 142 ; Er., Ins. Deiitschl, iii, 45 ; J. A. Power, Proc. 

 Ent. Soc, 1 Nov., 1869; Ent. Mo. Mag., vi, 172. 



Three specimens of this most interesting insect were taken 

 by Dr. Power on 23rd July last, near Esher, and determined 

 by Dr. Sharp; and on 7th August Mr. Oliver Janson caught 

 a single specimen of it by promiscuous sweeping in the even- 

 ing, at Shirley, near Croydon. 



The genus Triarthron, Markel, has hitherto been the 

 only one of the AnisotomidcB not represented in this country. 

 Agreeing with Hydnohius (which it must precede in our 

 lists) in having all the tarsi five-jointed, a simple mesoster- 

 num, and the thorax margined behind, it is instantly dis- 

 tinguishable fi'om that genus by the club of its antennae being 

 composed of three joints only. These characters separate it 

 from Anisotoma (to certain species of which genus it bears 

 a very superficial resemblance), in which the anterior and 

 middle tarsi have each five joints and the posterior only four, 

 the mesosternum is keeled and the club of the antennae is 

 irregularly five-jointed. A fortiori they serve to remove it 

 effectually from Cyrtusa and Colenis, with which genera, on 

 account of a certain resemblance in facies, it is associated by 

 Fairmaire and Laboulbene. 



The sole species in the genus, T. Mdrheliij is very rare on 

 the Continent, and has occurred in Saxon Switzerland, Thu- 

 ringia, Austria and France. It is about the size of Anisotoma 

 rubiginosa, though rather longer, convex, shining, reddish- 

 yellow, with rounded sides to the thorax, which is contracted 

 in front, and nine strongly punctured striae to each elytron, 



