702 
DR W. T. GORDON ON CAMBRIAN ORGANIC REMAINS 
cyathus fultus is concerned, they appear to be organs of fixation, but they might also 
act as stolons, as was suggested in connection with similar strands in the former 
species. In S. atlanticus, however, there was no coalescence into exothecal lamellae. 
It is interesting to note that such lamellae have been recorded in two other forms, 
Archaeocyathus profundus , Billings, and A. Sellicksi, Taylor. In neither of these 
cases has any confluence of small circular rooting structures been noted, but Taylor 
states that new cups may arise from the exothecal mass (A. SellicJcsi), so that a 
certain amount of evidence exists pointing to the possibility that these processes 
function like stolons and produce new individuals. 
Actual fixation has only been seen in one section, and this is shown in PI. Ill, 
fig. 34. The cup is cut very close to the end, so that the central cavity c alone is 
obvious. The outer wall, o.w., is also indicated, and round the whole are two 
layers concentric with the walls. Attached at one side is a process, r.pr., which 
is fixed to a fragment of the cup of Metaldetes plicatus at b. 
On account of the mass of enveloping lamellae, and also since the walls and septa 
show considerable thickening, the details of the pores are difficult to determine. In 
longitudinal section (fig. 62) the pores of the outer wall are easily seen in several 
places, but the pore lumen is much reduced by thickening of the walls. The 
regularly placed tabulae are also well marked in this figure (fig. 62, t, t, t). The pores 
run about 5 per mm. The porous structure of the inner wall is only shown on the 
weathered surface (PI. V, fig. 50). There are two rows per intersept, and they number 
5 per mm., as on the outer wall. 
On account of the septal thickening, the porous structure on these elements has 
not been ascertained, although the pores are shown perforating the primary lamella 
(text-fig. 1 e, p). Tabulae are shown in both figs. 60 and 61. They are very finely 
perforate ; indeed, they might be described as net-like, since the pores are quite 
irregular in their distribution and closely pressed together. There are about 10 
pores per mm. in any direction on the tabulae. 
Lastly, in the centre of the cup a mass of coralloidal tissue similar to that 
recorded by Taylor in Somphocyathus is very evident in PI. VI, fig. 60. As noted 
earlier in this paper, similar coralloidal tissue has been discovered in Archaeocyathus 
trachealis and Syringocnema gracilis , so that it can no longer be considered as an 
abnormality. 
Coscinocyathus endutus ,* n.sp. 
The second species of Coscinocyathus is represented by a considerable number of 
specimens cut in various directions, so that a more detailed examination has been 
possible. Like C. fultus, this form is quite dissimilar to any of the species so far 
recorded, the nearest being probably C. irregularis, Von Toll. 
One of the chief diagnostic characters is the extraordinary mode of fixation. 
Gk. endutos, clothed. 
