THE EUPODA, OR PHYTOPHAGA. 223 



yellow legs, and the fifth joint of the antennae enlarged 

 in the male; and brassicae, the least of all, has four 

 yellow spots, and resembles a very small tetrastigma, 

 being, however, more globose. In this species, also, the 

 fifth joint of the antennae is somewhat thickened in the 

 male. 



The species of Plectroscelis and Chtetocnema have 

 their hinder tibiae armed with a tooth on the outer side 

 below the middle; and Thy amis, a genus of large ex- 

 tent, may be known by the elongate basal joint of its 

 hind tarsi, which is about half the length of its tibiae. 

 Although its members are usually of dull-yellowish 

 colours, there is one, T. dorsalis, of great beauty, being 

 intensely black and shining, with the thorax and a 

 broad sharply-defined margin all round the elytra bright 

 red; it occurs somewhat rarely at Mickleham, Wey- 

 mouth, and the Isle of Wight. 



Psylliodes is more robust, compact, and inclined to 

 an elongate-oval in outline ; the basal joint of its hind 

 tarsi is elongate, but differs from that of Thy amis and 

 its other allies in being inserted not at, but above the 

 apex of its tibiae, which is sloped off: here, also, the 

 antennae are more distant at the base. 



Of the remaining genera Apteropeda and Mniophila 

 are conspicuous for their extreme rotundity and convexity; 

 A. graminis (Plate XV, Fig. 2), either bronze or bluish- 

 green in colour, being abundant in autumn among all 

 kinds of wild plants, and M. muscorum, more like a 

 black seed, or a little round Acarus, than a Haltica, 

 sometimes occurring in moss. 



The CASSIDID.E, or Tortoise-beetles, are entirely un- 

 like any other British Coleoptera (except, perhaps, Thy- 

 mains limbatus], on account of their broad, flattened 



