462 PALAEONTOLOGY OF ILLINOIS. 



ar branches, Pmnularia capillacea, Lindl. and Hutt., is very 

 abundant in the coal shales, especially with coal No. 3. The 

 State Cabinet has numerous specimens of it. 



It may not be out of place to mention here the remarkable 

 Gyromices ammonia, Gopp. PI. 38, fig. 6, 66. A spiral, organized 

 body, which has been referred, by Prof. Goppert and other Ger- 

 man authors, to a species of fungus, found under or within the 

 coaly matter of some leaves and stems of the coal shales. This 

 species is abundant at Colchester with the remains of various 

 plants, under the leaves of Callipteris Sullivantii, Pecopteris, 

 Stigmaria, Cordaites, etc. It is true that these remains appear 

 sometimes within the coaly matter of the plants, or imbedded 

 in it, a circumstance which may have led the German Palaeon- 

 tologists to consider the species as a fungus. But in most 

 instances, these small bodies have left their prints deeply 

 marked, or rather their casts, in the shales, under the coaly 

 matter of the leaves. Their substance was consequently hard. 

 It is thus easy to understand that if ever they lived under the 

 leaves or floating stems, the pressure has forced them some- 

 times within the softened substance of the leaves and stems, as 

 it has forced them within the clay. I have examined many 

 specimens of this species under divers circumstances of posi- 

 tion, etc., and cannot consider them but as the small, thick 

 shells of an Annelid. Professor Dawson, of Montreal, who 

 examined this species a long time ago, has considered it in the 

 same light, and named it Spirorbis carbonarius. The shell 

 makes about two spiral turns, and is marked crosswise by 

 strong ribs, each separated by three or four thinner ones. Fig. 

 6 shows a cross section of the species. Fig 6 and 6 a are en- 

 larged ten diameters. 



