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T IT E ("j E N U S P TT .K 7) A^ 



By thk Rkv. W. W. lM>\vr,Ei!, I\r.A., FJ^.S. 



As there seems to be so much misunderstanding about tlie 

 different species of the genus Pluedon, it niaj' perhaps be useful 

 to say a few words concerning the group, especially as the subject 

 has been lately discussed in the pages of the 'Entomologist.' 

 Stephens places fourteen species in this genus, including in it our 

 genera Plagiodera, Prasocaris, Phratora, Pluedon, Gastrophysa, 

 and one Chrysoinda, viz. fastnosa. Of all these none, except 

 Plagiodera, have any affinity to the Pluedons proper. It miglit 

 seem, indeed, at first sight, that Plagiodera armoracice was a real 

 Phcsdon ; it is, however, generally distinguished by the ventral 

 segments of the abdomen, and by its much flatter and less convex 

 appearance. It is decidedly a rare insect, and I have not heard 

 of its being taken since Mr. G. C. Champion found it a few years 

 ago. It is said to be found beneath the bark of willows, or at the 

 roots of grass in marshy places ; the latter habitat seems to agree 

 better with the nature of the whole group, and very probably the 

 willow bark only serves it as a refuge from weather, or as winter- 

 quarters, as it is a very common thing to find allied species of the 

 ChnjsomelidcE under bark of trees in winter. We have, then, left, 

 four species of Pluedon proper, which may be treated of in 

 order : — 



Phcedon tumididum, Kirby.— This species, which has no 

 synonyms, is easily distinguished by its thorax being distinctly 

 punctured at the base only, the rest being smooth ; it is of a dull 

 dark blue or olive-green colour, and not very variable. It is 

 exceedingly abundant in spring and summer on hedge-sides and 

 ivy banks; in fact I have seldom swept any locality without 

 coming across it somewhere or other. I never remember, though, 

 to have found it on marshy, or even damp, ground. 



PhcBdon betida. — Dr. Sharp, in his Catalogue, assigns this 

 species to Linne, and gives the P. hetulce of Waterhouse's Cata- 

 logue as a synonym of P. cochleariw ; whereas in Waterhouse's 

 Catalogue Phcedon armorac'uB, Linne, P. cocldearia'. , Fab., and 

 P. hetid(e, Suffr., are given as synonyms for one species; and 

 Pluedon hetulce, Linne, and P. cochlear'ue, Sulfr., are given as 

 synonyms of another species. It is very probable that some 



