18 GEOLOGICAL SURVEY, CANADA. 



tubes that radiate outward and upward at varying angles. The 

 walls of the radial tubes are perforate, and divided by more or less 

 irregular incomplete septa. 



Orowth. — The mode of growth appears to have been essentially 

 the same as that of Archaocyatliincp, where individuals press against 

 each other that appear to have united at the point of contact by a 

 more or less confused compact growth. 



Affinities. — For the present and awaiting larger collections and 

 possibly much better material, a relation may be assumed with the 

 Porifera on the one hand and the Arclmocyatlmioe on the other, 

 with a strong tendency towards the first. 



Ohservaiions. — There are two species now referred to the genus: 

 A. lawsoni, n. sp., and A. irregularis, n. sp. One or two other species 

 are indicated, but the material is not sufficiently complete for 

 specific description. 



Genotype. — Atilohania lawsoni, n. sp. 



Atikokama lawsosi, n. sp. 

 (PI. I, figs. 1-5 ; PL II, fig. 2.) 



The general form of this species is elongate conical or cylin- 

 drical as far as can be determined from several fragmentary 

 specimens. Central cylindrical cavity relatively small and expand- 

 ing towards the upper outer portion of the central cavity. 



Walls. — The outer and inner walls are fairly well defined, but 

 owing to the condition of preservation none of their details of 

 structure are preserved. 



Tubes.— The walls of the tubes are pressed one against the 

 other so as to form a practically solid mass of tubes that have a 

 more or less hexagonal outline. The tubes are so arranged in the 

 cylindrical specimens that they radiate like the spokes of a wheel 

 from the inner to the outer walls and increase in number by inter- 

 polation of additional tubes. In one vertical section (fig. 1, PL I) 

 the tubes rise from the inner wall with a slope of about 10°-15°. 

 In other sections the slope is greater. The tubes vary in size from 

 a sharp elongate point where they start between other tubes to 

 2 mm. in diameter at their outer end. 



S'epio.— Incomplete, irregular septa occur in the tubes at 

 irregular distances. 



