Revieivs — Prof. Dana — On Palceozoic Botany. 177 



lycoperdon, I have no means of judging, not having access to the 

 original work. It is certain, however, that Prof. Hall (Pal. N.Y. 

 vol. i. pis. xxiii. and xxiv.) included under the name of Chcetetes 

 lycoperdon several distinct forms, such as C. petropolitanus, Pander, 

 C. Fletcheri, Edw. and H., and C. delicatulus, Nich. Under these 

 circumstances, the name of Chcetetes lycoperdon will have to be 

 abandoned ; unless, as is improbable, the original form described by- 

 Mr. Say can be clearly identified and shown to be distinct from 

 previously recorded forms. 



Amongst the forms included by Hall under the name of Chcetetes 

 lycoperdon, Say, there is, however, one (Pal. N. Y. vol. i. pi. xxiii. 

 fig. lg), which is far from uncommon in the Trenton Limestone and 

 Hudson Eiver Group of Canada, which appears to me to be so far 

 distinct that it may be provisionally separated under the name of 

 C. undulatus. This form is certainly very distinct from the 

 typical forms of C. petropolitanus, Pander ; since it never shows 

 a. concave base or concentrically-wrinkled epitheca, and ap- 

 pears to have been never free, but always fixed by its base. It 

 forms great lobate masses, sometimes more or less funnel-shaped, 

 and often undulated or deeply indented and folded laterally. None 

 of my specimens have the surface well preserved ; but so far as can 

 be determined, the calices are polygonal, thin walled, about six or 

 eight in the space of one line, destitute of minute intermediate tubuli, 

 and showing no well-marked tubercles, nor groups of large-sized 

 corallites. A rough fracture exposes the walls of the corallites, 

 which radiate from the base, and are often arranged in successive 

 layers or strata. Without insisting upon the specific distinctness of 

 this form, it appears to me to be sufficiently well marked and common 

 to deserve at any rate a provisional title. 



BEYIEWS. 



Notes on Paleozoic Botany, extracted from Dana's Manual of 

 Geology (Eevised Edition). New York, 1874. (Second notice. 1 ) 



WHATEVER may be the ultimate conclusion of Geologists in 

 relation to Eozoon Canadense as the very oldest form of life 

 met with on our Earth, it is certain that abundant remains of several 

 orders of animals have been obtained from rocks older than those 

 which have yielded any very good evidence of Plants. 



MM. Torell, Linnarson, Nathorst, and other observers, have 

 described various plant-like impressions in rocks of Cambrian age in 

 Sweden, 2 and Dr. Henry Hicks, F.G.S., has described similar indica- 

 tions observed by him in the Lower Arenig Eocks of Eamsey Island, 

 St. Davids. 3 



Prof. James Hall in America has also noticed impressions of sea- 

 weeds (Bnthotrephis) in the Trenton series (Lower Silurian), whilst 



1 For previous notice see Geol. Mag., 1875, p. 44. 



2 Geol. Mag. 1869, Vol. VI. p. 393, PL 11, 12, and 13. 



3 Op. cit. Vol. VI. p. 534, PL 20. 



DECADB II. — VOL. II. — NO. IV. 12 



