226 [March, 



Further, I find connected with tlie ekln the whole rectum, and a little 

 more of the intestinal canal, drawn out in piipation. A little below 

 I see a substance which I suppose to be your membrane, about as long 

 as the rectum, and structureless. I would suppose that the membrane 

 belonged to the rectum and perhaps the external cover of it, if you 

 had not written that the membrane in Archippus is black. I took a 

 caterpillar (in spirits) of this species, and oj)ening it, found that the 

 rectum was white, or at least light colored. One should make a section 

 of the caterpillar of ArcMppics just after suspension to discover w^here 

 this black membrane comes from. The use and purpose of the knobs 

 and bars in the chrysalids is doubtless this : in these organs are built 

 up and developed the anal appendages of the imago." 

 Coalburgh, U. S. A. : September, 1878. 



INTRODUCTORY PAPERS ON FOSSIL ENTOMOLOGY. 



BY HEEBEET GOSS, E.L.S., F.G.S. 



No. 5. 



PaJcEozoic Time. 



l_On the Insecta of tlie Permian Period, and the animals and plants 

 ivith which they were cor?'elated.^ 



The Permian* Period — w^hich bi'ings us to the close of the 

 Palaeozoic Age^ — was one of transition towards a new^ epoch in the 

 world's history, in which a number of old types of animal and vege- 

 table life appeared for the last time. 



Although the Permian rocks in many instances pass upwards 

 conformably into the Trias, the difference between the fauna and flora 

 of the two Periods is distinctly marked, the fossils of the former being 

 more nearly allied to those of the Carboniferous Age, than to those of 

 the latter or any succeeding series. 



The Permian rocks are extensively developed in Eussia and Ger- 

 many, and they also occur in some parts of Great Britain and North 

 America ; but from their comparatively limited geographical and 

 superficial range, the number of fossils obtained from them is propor- 

 tionately small, and of the Insecta only about thirteen species have 

 been discovered, all of which were found in that part of Germanyf 

 which has been styled by LyellJ " the classic ground" of this formation 

 on the Continent. 



* This formation was so named by Sir R. Murchison, F.R.S., on account of its being more de- 

 veloped in the Province of Perm, in Russia, than anywhere else. 



t Schwarzenbach, near Birkenfeld, Cassel ; Weissig, near Pillnitz, in Saxony : Stockheim, in 

 Thuringia, &c. 



t " Elements of Geology," (ith edit., p. iCO. 



