Introduction 
The insect material from the Eocene deposits of Denmark which 
I have had for examination, and which will be treated on the follow¬ 
ing pages, comprises — to the best of my knowledge — all insect 
finds procured from the Eocene deposits of Denmark. All the finds 
originate from the lower Eocene Diatom-earth bed occupying a limited 
territory round the western part of Limfjorden in northern Jutland. 
With a single exception (Rhamphidia sp. which has been found in 
»Moler« (Diatom-earth proper) the rock from which all the finds have 
been produced is the hard, chalky »Cementsten« (cement-stone) 1 ) in 
which the impressions keep better than in the soft, loose Diatom-earth. 
Only few insects have been previously mentioned in the literature 
as originating from the Eocene deposits of Denmark, and then only 
in a few phrases or remarks. 
The first author who speaks about them is Wiese who records 
»en Kalkskiver, hvori en Libellula fandtes indtrykt« from Fuur, in 
his Reise-Iagttagelser i nogle af de nordiske Lande V. 
1798 p. 240. 
Further Forchhammer in his Danmarks geognostiske For¬ 
hold 1835 p. 88 mentions »nogle Insecter af Familien Sirex (Hymen- 
optera terebrantia)« from »det hvide skifrige Ler« viz Diatom-earth. 
In the same year ( 1835) Beck’s Notes on the Geology of Den- 
mark (Proc. Geol. Soc. London II. p. 217) was published in which 
»the elytra of beetles, the cases of the larvæ of Phryganæa, and an 
liymenopterous insect which the author has called Cleptis Steenstrupii« 
are mentioned from a stratum which, according to the description, 
most likely is to be recognized as cement-stone. 
Finally Mørch in his Forsteninger i Tertiærlagene i Dan¬ 
mark (11. Skand. Naturforskermøde i Kbhvn. 1873 p. 273) records 
x ) The cement-stone appears as concretions which are to be found as a 
secondary part of the Diatom-earth formation, partly presenting rows 
of clumps, partly continuous, Vs to l /* m thick layers. 
