PLATE 4-5. 45*. 
The prototype of this very curious petrifaction is not at 
present known; but it doubtless belongs to the genus 
Om'scus *. 
Tab. 45. Fig. 1. Fragments of E. derb^ensis, as com- 
monly found in black marble. 
2. The body of a larger insect of the same kind in com- 
mon limestone. The fossil rarely occurs as large as this 
specimen : its usual size is that of the fragments in the fore- 
going figure. 
* The illustrious Linne considered his Entomolithus paradoxus, which 
though perhaps not the same species as our Derbyshire fossil, is very nearly 
allied to It, as a Monoculus (Syst. Nat. E. 12. p. 160.) His learned and 
ingenious editor Gmelin has not, however, followed his example. In the 
last edition of the Systema Natune we find the same fossil referred to the 
onisci : but here, under paradoxus, Gmelin probably confounds two, or 
more, diyinct species. After mentioning Dudley and Colebrookdale among 
the localities of his fossil, he describes it, as covered with a lamellous shell, 
composed of versatile, triarcuate rings or segments — “ testa laminosa ex 
annuhs versatihbus tnarcuatis ’’—which, as well as a prece- 
dent clause,— “C'a/uife supra ad latera hemispharicis aut cylindricis 
duobus tubercuhs notato,” perfeetly well characterises the species common 
at both the abovementioned places. He afterwards, however, adds “ Cauda 
tenui per tria tubercula tripartitfi." This by no means agrees with the 
figures he refers to (his references are the same as in the 1 2th Ed. of the 
Syst.) nor with any of the numberless specimens we have had an opportu- 
nity of examining from Colebrookdale and Dudley. Doubtless, his descrip- 
tion IS accurate, as far as respects the fossil he himself has observed ; but we 
think this must_ have been specifically distinct from the Entomolithi gene- 
rally procured m Shropshire, Staffordshire, and Worcestershire, though 
agreeing with them m many particulars. » Cauda tenui,'^ &c. would 
apply to our lunatds, (Tab. 45. f. 4.) but the other parts of the description 
do not answer to it. 
