294 THE ENTOMOLOGIST. 



confusion has arisen at some time or other between Plagiodera 

 armorac'uE and Phcedon armoracue, which latter is plainly the 

 insect that we are to understand by the P. hetulce of Dr. Sharp's 

 Catalogue, as they are exceedingly alike at first sight, owing to 

 their very prominent shoulders and general appearance. I think, 

 then, that this P. betulce, which stands next on our list to 

 P. tmniduliun, is Linne's Chrysomela armoracice, and not the 

 insect he meant by C. hetidce. It is a very distinct species, and 

 is easily distinguished from P. tumididum, which it much resembles 

 at first sight, by its thorax being distinctly punctured all over, and 

 by its very prominent shoulders. I have always found it an un- 

 common insect, and have never taken it, or heard of its being 

 taken, except in damp or marshy places. 



Phcedon cochlearice. — This is usually considered to be the 

 Chrysomela cochlear'ue of Fabricius, although Mr. Waterhouse 

 apparently considers Fabricius's insect to be synonymous 

 with the preceding species. Thomson (Skand. Coleopt., viii. 

 273), assigns it to Fabricius, and his authority is of great 

 weight. If Linne by his C. hetidce meant one of our Phcedons, 

 and not Phratora vulgatissima or some quite different insect, I 

 am inclined to think that it is this species to which his name 

 must be attached. This is the insect referred to in the ' Entomo- 

 logist' for this present year by Mr. Hart (Entom. xiv. 187) and 

 by Mr. Billups (Entom. xiv. 237). It is easily distinguished from 

 the other species by the punctuation of its thorax, its less convex 

 shape, and the peculiar brightness of its colour ; it seems peculiar 

 in that it appears to have no particular preference for either dry 

 or marshy ground. Mr. Billups has shown how abundantty he 

 has found it on a dry field ; and I have taken it in company with 

 the preceding species in a marshy place near Eepton, and on 

 cruciferous plants growing actually in the water near Lincoln. 

 This species is perhaps the most injurious to man either of this 

 or the allied genera, as it seems to attack useful plants to a greater 

 degree than its congeners. 



Phadon concinmim, Steph. — This species is distinguished from 

 the preceding by its rather more convex shape, and by its being 

 almost universally of a bright green colour, P. cochlearice being 

 nearly always blue ; the interstices of the elytra in P. concinnum 

 are coarsely punctured and wrinkled, whereas in P. cochleario} thej'^ 

 are only very finely wrinkled. I have not heard of this insect 



