Cri/pfozoon and other Ancient Fomls. 



215 



formations in which it lias liitlierto been found. In any 

 case it sliould be looked for in the i*re-canibrian beds. 



The latest atteni]»t known tome to unravel the relations 

 of Kece])taculites is that of Dr. Ivaufi' in the Transactions 

 of the ( lerman Geoloj^ical Society. He rejjcats and con- 

 firms the . oUservations of Billintfs as to its structure, 

 ditlerinf; only in rejecting the pores of the internal wall. 

 He also ritjhtlv concludes that it must have been a calca- 

 reous organism, and consequently cannot l)e referred to 

 any of the groups of silicious sponges ; but seems to regard 

 its systematic position as still (piite uncertain. It may 

 possibly remain so, till either moilern analogues, or more 

 ancient and simpler forms, shall be discovered. Jvece})ta- 

 culites and its allies are at present known as low as the 

 Lower Ordovician on the one hand, as high as the Carbon- 

 iferous on the other. 



Another primitive and ai)parently very generalised type 

 is the genus Arckaocijathnx of J>illings, one of the oldest 

 and most curious Cambrian fossils. It deserves an addi- 

 tional notice here, in connection with facts and publications 

 of recent dates. 



As early as 18G5 my attention was attracted to these 

 forms by specimens presented to me by Mr. Carpenter, a 

 missionary to Labrador, and about the same time Mr. 

 Hillings was kind enough to shew me specimens wliich 

 had been obtained by Mr. Itichardson of the CJeological 

 Survey, in what was then known as the " Lower Potsdam " 

 of L'Anse a Loup in that region, and which he had 

 described in 18G1 and 18G4, stating that he was in doubt 

 whether they should be referred to corals or sponges 

 Slices of the specimens were made for the microscope, 

 when it appeared that, though they had the general aspect 

 of turbinate corals, like Petraia, etc., they were (piite dis- 

 similar in structure, more especially in their porous inner 

 and outer walls and septa, yet they did not closely 

 resemble the porous corals, which besides were regarded as 



