﻿Cryptozoo7i and other Ancient Fossils. 213 



described by him as a sponge, under the name Strejytochetus 

 ocellatus} and appears to be generically the same with 

 Nicholson's species, though belonging to an older forma- 

 tion. These bodies occur in small rounded or elliptical 

 masses, presenting a concentric structure resembling that 

 of Cryptozoon on a small scale. Under the microscope, 

 in specimens kindly communicated to me by Prof. Seely 

 and Mr. Wethered, the layers are seen to be made up of 

 minute tubes twisted together in a most complicated man- 

 ner. The tubes are cylindrical, smooth, and apparently 

 calcareous, and they do not occupy the whole space, but 

 leave irregular unoccupied cavities. The tubes make up 

 the layers and there do not seem to be any distinct 

 separating lamiuie between the layers, or any included 

 earthy matter. In these respects they differ structurally 

 from Cryptozoon, and are certainly at least generically 

 distinct, though having some resemblance in general 

 manner of growth. 



Girvanella gives us little assistance in determining the 

 affinities of Cyptozoon, and its own relationships have 

 been very variously interpreted. It has been referred to 

 Hydroids, Protozoa and even to Algie. Prof. Penhallow, 

 however, who has examined my specimens, does not seem 

 inclined to refer it to the latter, though it has certain 

 resemblances to some of the Siphone^ie. Perhaps the 

 most probable conjecture as to its affinities is that 

 advanced by Nicholson,^ who compares it with the recent 

 tubulous Foraminifora of the genera Syringammina and 

 Hyperammina of Brady, whose tests present masses of 

 tortuous and in some forms branching tubes, sometimes in 

 concentric layers. 



I have recently been able -to extend the range of this 

 curious organism downward, by the discovery in a boulder 

 in a conglomerate at Little Metis of numerous examples 



1 American Journal of Science, 1885. 



i Nicholson and Lydeker, Manual of Palaeontology, 1889, p. 127. 



