FROM A DREDGING IN THE WEDDELL SEA. 
683 
point about 85° S.) No evidence has been obtained, however, as to how far to 
the south of 62° 10 r S. we might expect to find the band from which the material 
was derived. 
Although the specimens were dredged in 1903-4, it was not until 1913 that 
Dr Bruce handed the material over to me ; meanwhile Archaeocyathinae had been 
recorded from the Beardmore Glacier moraines by Professor David, Priestley,* and 
T. G. Taylor.! None of their specimens, however, are specifically determinable with 
certainty ; indeed, it is' open to doubt if they are generically recognisable. That they 
do belong to the group is perfectly certain, and two families are represented — 
Archaeocyathidae and Spirocyathidae, — according to Taylor’s investigations. 
In the present instance most of the forms are well preserved, and specific 
determination is perfectly easy as far as the material is concerned. The skeleton 
consists of granular calcite, and the matrix of rather turbid crystalline calcite. 
Occasionally the original skeleton has been leached out and subsequently replaced 
by clear crystalline material. In such cases the details of the skeletal structures 
may be obliterated, but in many examples the turbid matrix has remained and pre- 
serves the porous structure at least. All types of preservation are often distinctly 
seen in the same specimen. A section of Coscinocyathus endutus is represented 
in PI. I, fig. 1. It is cut to pass vertically through the inner wall, which is shown 
along the centre of the figure. The outer wall with its pores occurs at c, while 
between the walls are the interseptal loculi. An examination of the inner wall at 
a proves that the original wall is present, and the pores are filled in by the 
cloudy matrix ; but at b the wall has disappeared, and the space is filled with clear 
crystalline calcite. The pores are indicated, however, by the matrix which originally 
filled them in. At various parts of the same figure the outer wall, septa, and tabulae 
have been similarly destroyed, but no difficulty arises in the determination of these 
structures. 
In one or two examples exposed on the outside of the block, the less resistant 
character of the granular skeleton is again indicated. The pores of the outer wall 
are then represented by papillae (PI. I, fig. 2, along both sides of the skeleton in the 
lower part of the figure). Such papillae are really the portions of the matrix which 
filled in the pores, while the spaces between the papillae were originally occupied by 
the granular calcite of the wall. Along the septa as at a of this figure the apparent 
pores are really where the solid portion existed, but this has been dissolved out, and 
the matrix is left as a continuous bridge between adjacent loculi. A similar feature 
may be noted across the tabulae at b. Even in such cases, however, no difficulty 
occurs in interpretation. 
In addition to the remains of Archaeocyathinae, other organisms are represented 
in the limestone. Fragments of shell and the carapace of trilobites occur, but- 
* Compte rendu du XT Congres Geologique International, 1910, p. 774. 
f British Antarctic Expedition, 1907-9, “ Geology,’' vol. i, pp. 235 et seq. 
