Memoirs of the Kyancutta Museum 
No. 4 
KYANCUTTA, South Australia 
September, 1937 
Further Notes on 
Archaeos (Pleospongia) 
From the LOWER CAMBRIAN of South Australia 
By R. & J. Bedford 
Since our third memoir was published last year, we 
presented at the Auckland meeting of the Australian and 
New Zealand Association for the Advancement of Science 
a paper on the Structure and Classification of Archaeos. 
Mimeographed copies of this paper have been distributed, 
and, at a later date, we hope to revise the matter and 
print it as a memoir. We are also getting together a 
collection of photographs of material specially prepared 
for this purpose, with a view to publishing a series of 
photographic illustrations, 
N 
We have received from Dr. V. J. Okulitch notes of 
a paper presented by him at the Cincinatti meeting of 
the Geological Society of America, in which certain 
changes in nomenclature are proposed. 
Owing to preoccupation of the name Cyathospongia 
proposed by Dr. Okulitch for the class, he now suggests 
Pleospongia, which name we have accordingly adopted. 
Both Dr. Okulitch and ourselves had discovered the 
preoccupation of our name Heterocyathus, for which 
Dr. Okulitch proposed to substitute Radiocyathus and 
we Hetairaccyathus; in a letter Dr. Okulith has very 
courteously offered to withdrawn his proposal, and we 
propose to continue to use the names Hetairacyathus, 
Hetairacyathidae for our genus and family, and 
Hetairacyathina for Dr. Okulitch’s order. 
Dr. Okulitch also proposed to use the name 
Archaeocyathidae instead of Spirocyathidae, and to ase 
Cambrocyathidae for “Archaeocyathi with straight 
parietes as represented by A. profundus Billings.” As 
we have not yet seen the full text of Dr. Okulitch’s 
paper, and the correlation of the Australian and Ameri- 
can forms presents considerable difficulty, we are, in this 
paper, continuing temporarily to use the names Spiro- 
cyathidae and Archaeocyathidae in the same sense as in 
our previous memoirs. 
Order SPIROCY ATHIN A. 
New Species Protopharetra jurca. i 
This fossil occurs ın rather poor preservation in 
association with Beltanacyathus ionicus near the 
“Paint Mine,” Beltana. Most of the specimens are 
surrounded by exothecal tissue which forms a common 
investment to them and the associated Beltanacyathus. 
We conclude that this exothecal tissue is probably a 
parasitic investing form related to that which is 
described later in the present paper under the name of 
Exocyathus and to  Vologdins Labyrinthomorpha 
(Archaeocyathinae of Siberia, 1931, p. 35, and Plates 
V, VIII, X, XIV, XVI). The most striking feature of 
` Protopharetra, furca is its branched form, as is well seen 
in Plate XXVIL Fig. 106 Aa, in which the left-hand 
specimen, seen approximately in transverse section, has 
a four-lobed outline and four distinct central cavities. 
In this figure, b is a section of Belianacyathus, and c is 
a common investment of (2) Exocyathus. Fig. 106 B 
shows a part of the same specimen enlarged, with two 
of the lobes and their cavities cut transversely, and a 
third lobe (bottom right) obliquely; Exocyathus tissue 
is seen Cut transversely, partly surrounding the left-hand 
lobe. The outer wall, though defined, does not give a 
clear view of the pores because of the attached 
Exocyalhus. The intervallar mesh is of fairly regular 
open texture, composed of round rods spaced, on an 
average, about half a millimetre apart. There is little 
or no sign of such a radial arrangement of the rods as is 
seen in Spirocyathus. The inner wall is clearly defined, 
but so far we are not quite satisfied as to the nature 
of the pores. In the type specimen some pores appear 
to be about 4 mm. diameter, whilst in a few places 
smaller, more numerous pores appear to be present; in 
another specimen, which may be the same species, the 
inner wall seems to have more uniform pores, 4 mm. 
