August, 1909.] 169 



ON THE BRITISH SPECIES OP ANAC^NA, Thomson. 

 BY JAMES EDWARDS, P.E.S. 



As the result of a recent study of considerable material in our 

 British forms of this genus, and having regard to the stability of the 

 differences that obtain between the darker and lighter forms which 

 we now include under the name limbafa, Fab., it appears to me that 

 the practice of those writers who treat these forms as two distinct 

 species is to be preferred. The differences in question are not such 

 as appear very striking on paper, and the adequate expression of all 

 of them would require descriptions of quite unusual length and 

 complexity ; but they are nene the less real and combine to form a 

 habitus which is very nearly unmistakeable. The insects themselves 

 are, fortunately, so common that any one may compare them. 



The more readily described characters of our native species may 

 be expressed as follows : — 



1 (2) Mesosternum simple. Insect broad-oval, very convex, pitch-black with the 



sides of the thorax and elytra conspicuously pale globulus, Payk. 



2 (1) Mesosternum produced into a sharp, triangular, more or less backwardly- 



directed tooth in front of the middle coxse. 



3 (4) Upper-side pitch-black, the sides of the thorax very narrowly and the apex 



of the elytra paler. Sides of thorax strongly curved in the front half, 

 nearly straight behind. Puncturation of elytra deeper than in ovata. 

 Body in the lateral aspect higher in proportion to its length, the apical 



slope of the elytra consequently more steep limbata, Fab. 



4, (3) Elytra yellow-brown or brownish-yellow ; in life bearing a common oblong 

 black spot just before the middle, and a narrow dark sutural stripe, but 

 these markings are very fugitive, and usually absent in specimens which 

 have been long dead. Body in the lateral aspect not so high in proportion 

 to its length, the apical slope of the elytra consequently less steep. 



5 (6) Head black, sometimes with the free edges of the forehead narrowly yellow- 



red ; thorax piceous, with the sides broadly and suffusedly pale ; maxillary 

 palpi with the last joint entirely pitch-black. Sides of thorax evenly and 

 feebly curved throughout. Body in the lateral aspect higher in proportion 

 to its length than in hipustulata. ovata, Reiche. 



6 (5) Head black, with a large triangular yellow-red spot on each side in front ; 



maxillary palpi with the last joint suffusedly red-yellow for a greater or 

 lesser distance from the base. Thorax brownish-yellow, with three, usually 

 contiguous, dusky spots, viz., a rhomboid one in the middle, and one on 

 each side in the shape of a triangle, of which one point touches the base : 

 the situation of these markings gives the effect of two pale triangles 

 standing on the base of the thorax, one to the right and the other to the 

 left of the scutellum. The palest and flattest of our species... 



bipustulata, Marsh. 



