These insects, like the Donaciae from which they have been 

 separated, are fond of aquatic plants ; both species are rare, 

 and may be distinguished from the Donacias by the very mi- 

 nute penultimate joint of the tarsi, and the great length of the 

 terminal one : the mucronated elytra, their colour, and the 

 manner in which they are punctured, are characters totally 

 different to the British Donaciae. I shall only observe re- 

 specting the trophi, that I could not discover that the mandi- 

 bles were bifid at the apex. 



1. M. Zosterse Fab. Syst. Eleut.—Gyll. 4. j9. 683, \1.—Ahr. 

 Jasc. 12. pi. 14. — muticum Fab. Fnt. Syst. v. 1. pars 2. 

 p. 306, w. 11. 

 About half the size of the following species. Smooth, 

 ochraceous. Head excepting the trophi, black and hoary 

 with 2 elevated lines between the eyes, forming a deep fovea. 

 Antennae brown, the underside of the 3 first, and the tips of 

 all the other joints ochreous. Thorax not longer than broad, 

 a fine channel down the centre, and an oblique brown line on 

 each side. Scutellum black. Elytra pale ochreous, shining, 

 acutely acuminated at the apex (sometimes with an additional 

 minute tooth), the suture black, and each side below the 1st 

 punctured stria, which is abbreviated ; 3 double and 1 single 

 rows of black punctures, and 3 rows not black, less strong 

 and regular than in M. Equiseti. The tarsi similarly spotted 

 but fainter. Underside silvery glaucous. 



Excepting in size there is so little to distinguish this from 

 the following species, that I think our specimens at least are 

 only varieties, for I have never seen an example with biden- 

 tated elytra as described by Fabricius and Gyllenhal. This 

 pretty insect was first discovered in Britain, I believe, by Mr. 

 Spence, who took it in June upon aquatic plants at Kingston- 

 upon-Hull, Yorkshire; it was soon after taken on the banks 

 of the Yare between Thorpe and Norwich, the 14th June, 

 1811; the Rev. T. Ski'imshire met with it near Burnham, and 

 afterwards near Wells in Norfolk, the 29th of May, in salt 

 water ditches. It is said also to inhabit the Horned Pond- 

 weed {Zannichellia paliistris). 



2. M. Equiseti Fab.— Curt. B. E. pi. 318.— -appendiculata 

 Panz. 24. 17.— Zosterae Gyll. 3. p. 669. 

 For the loan of this fine insect I am indebted to the Rev. 

 L. Jenyns ; a pair were taken in the spring by Professor 

 Henslow, whilst fishing for shells, upon floating weeds in a 

 brook running into the Cam at Backsbite near Cambridge. 



A * has been erroneously attached to this species in the 

 ' Guide,' but I do not possess it. 



The plant is Equisetum arvense (Cornfield Horsetail). 



