24 GEOLOGICAL MEMOIRS. 



the author thinks is important as proving the existence of organic 

 life at the time of their deposition. The Hercynian and Bojic gneiss- 

 formations together are held to represent the Lower Laurentian 

 system of Canada ; the Hercynian mica-schist, the Upper Lauren- 

 tian or Labrador series ; and the Hercynian clay-slate, the Huronian 

 of Canada and the Cambrian of England. Prof. Giimbel then de- 

 scribes the mineralogical characters of the Hercynian gneiss, and 

 afterwards shows that a stratified ophicalcite occurring near Stein- 

 hag, exhibits structures corresponding with those of the Canadian 

 Eozoon in addition to other appearances which he also believes to be 

 of organic origin, and some of which he compares to the sections of 

 certain Bryozoa. 



The occurrence of a second species of Eozoon, to which he gives 

 the name Eozoon Bavaricum, has been discovered hj him in a rock 

 consisting of a granular aggregation of calcite, serpentine, and a 

 white hornblendic mineral, arranged in flakes or stripes. The rock 

 belongs to the Hercynian Clay-slate formation, supposed to be of 

 Huronian or Cambrian age, and the specimens examined were ob- 

 tained from near Wunseidel and Thiersheim, and between Hohenberg 

 and the Steinberg, especially the last-named locality. It exhibits: — 

 (1) A thin band almost entirely calcareous, and traversed by a network 

 of straight lines, or, when treated with acid, divided by band-like ribs 

 into irregular cell-like spaces, the calcite filling which is seen to be 

 granular. (2) Thicker calcareous portions abounding in tufts of fine 

 tubes, exactly as in Eozoon ; these tubes end at the serpentinous 

 portions (3), which have generally the same form as in the Eozoon 

 from Steinhag before described, but are much smaller. In decal- 

 cified examples they may be seen to possess the same vaulted mar- 

 gins as Eozoon; their breadth averages -1 milhm. and the diameter 

 of the tubes -01 millim. Generally these serpentine bands pass into 

 an adjoining portion (4), of one-half the width, or less, made up of 

 very much twisted lamellae, consisting of serpentine or a whitish mi- 

 neral, and possessing highly vaulted and deeply channelled outHnes. 

 Prof. Giimbel considers that on the whole these characters un- 

 doubtedly prove the affinity of this more recent and very much smaller 

 form to the group Eozoon; but as the last- mentioned structure (4) 

 differs from what has been observed in Eozoon Canadense, he gives 

 it the distinctive name of Eozoon Bavaricum*. 



In conclusion Prof. Giimbel describes certain structures which 

 appear to indicate with greater or less probability the presence of 

 Eozoon in the pargasite of Pargas in Finland, in the coceolite-hme- 

 stone of New York, in ophicalcite from Tunaberg, in a granular lime- 

 stone containing chondrodite, hornblende, and garnet, from Boden 

 in Saxony, in a blackish serpentinous limestone from Hodrisch in 

 Hungary, and in ophicalcite from Reichenbach in Silesia. 



[H. M. J.] 



* Dr. Carpenter has lately recognized the similarity of the Connemara 

 Eozoonal structures to those of Eozoo7i Bavaricum {supra, Part 1, p. 228). This 

 observation is of considerable interest when viewed in connection with the rela- 

 tive geological age of certain Eozoonal rocks, more especially the probable Cam- 

 brian date of Eozoon Bavaricum, the Lower Silurian position of the Connemara 

 serpentine, and the Laurentian age of Eozoon Canadense. — Edit. 



