PaJceozoic Fossils. i^Sl 



SpirojjhyUm. 



Mr. Sewai'd has pronounced this fossil to be probably of 

 mechanical and not of vegetable origins bnt the South African 

 form is so definite that it is hard to assent to this. The thallus, 

 supposing it to be an alga, is wound round on a central stem 

 which has a definite I'oot : the thallus has clearly marked sickle- 

 sha])ed I'ibs, and is b()rder(Ml ])y a well defined i-im ; it is folded 

 over itself in places, just as a thin membrane floating in water 

 would be folded, if laid down on a flat surface. Resides this, a 

 form consisting not of broad tliin leaves, but of long rounded rods 

 wound round a central axis, sci-ew-wise, exactly as in the common 

 kind, was found by Mr. Rogers and myself at Touw's River, in 

 beds which near by have yielded the ordinary Spirojihuton ; this, 

 however has been pronounced by Mr. Seward to be probably the 

 root of some tree. The material in the Albany Museum does not 

 admit of any further statement as to the nature of this problemati- 

 cal fossil, but I use the expressions Sj)i r(H)]iijt()H sp. a and S. sj). h. 

 to denote the two forms which this screw-like structui-e presents. 



I have compared the South African Spirophijtun sp. a. with 

 specimens of an almost identical form from the Devonian of the 

 Eifel, called by Kayser S^). eifelense,^ and I cannot see how these 

 markings could be produced by stirring sand in water, as Potonie 

 states,^ seeing that the " thallus" winds regularly through se, eral 

 centimetres of rock. 



The Howison's Poort specimens occur in a micaceous san<[- 

 stone coloured grey with carbonaceous matter, and there is a 

 possibility that some specimens showing definite structure may be 

 olitained from this locality. 



I have been unable to examine the American form Hji. laada 

 (/alli^ Vanuxem' from the Cauda-galli grits of Madison, or the 

 Sp. cauda j/Jiasiana, de Koninck"', from Duntroon, New South 

 Wales, the first from Devonian strata, and the second api)ai-en(ly 



I Ann. S. A. Museum, Vol. IV., pt. 1, 1903, p. 103, PI. XIV., figs. 1 & '2. 

 - Neue Fossilien aus deni Rlioiiiischen Devon, Zeif . deutsch. Geol. Ges. 

 Vol. XXIV, 187'?, p. 091. 



' Lehrbuch der Pflanzenpalaeontologie, Berlin, 1S92, p. 691. 



