Coscinocyathus annulatus (new species). Fig. 17. 
The shape is conical or (?) tubular; intervallum 5mm; 
central cavity (?) about 8mm. Septa very numerous, 
about .5mm. apart, with very numerous fine circular 
pores. Tabulae very numerous, 1.5mm. apart, with very 
numerous minute circular pores. The outer wall is not 
well seen in our specimen. Inner wall; the characteristic 
feature is the regular quadrate arrangement of the pores, 
one to each intercept, with the horizontal rows of parti- 
tions between the pores prolonged to form annular shelves 
projecting inwards into the central cavity. The species 
differs from C. aulax (Taylor) in the wider intervallum 
and the much more numerous tabulae. Only one frag- 
ment has been found. 
Coscinocyathus papillipora (new species). Fig. 18. 
Conical; intervallum coefficient 1.5mm : 4mm. Septa 
26 in number at 7mm. diameter, with numerous fairly 
large pores. Tabulae remote (? 10mm. or so apart), 
with numerous small pores. The outer wali has one or 
two rows of very characteristic pores per intercept, each 
pore entering a hollow hemispherical papilla projecting 
outwards from the wall, with an external perforation m 
the lower part of the papilla. The inner wall is also very 
characteristic; each intersept has a single row of thick- 
walled tubular pores leading upwards and inwards into 
the central cavity. Only one specimen has been found 
of this very remarkable little Coscinocyathus, but it is ın 
excellent condition and clearly defines the species. 
Coscinoptycha unilinearis (new species). Fig. 19. 
Only a more or less fiat fragment, about 30 x 20mm., is 
preserved. ‘fhe intervallum is exceedingly narrow, prob- 
ably less than 1mm. Sepia very delicate, regular and 
numerous, .ómm. apart, with numerous fine pores. One 
wallis very characteristic, with a single very regular line 
of pores occupying the centre of each intercept; the pores 
are often more or less elongated in the longitudinal direc- 
tion. The other wall has two rows of very fine pores to 
the intercept. From the small fragment it is impossible 
to be sure which wall is outer and which inner; but the 
slight curvature favours the coarse-pored wall as being 
the outer. The tabulae are from 2 to 5mm. apart. 
Note:—After this account was prepared for the press 
another fragment was found which clearly shows the 
coarse-pored wall as being the outer one. 
is a small cone, with numerous roots, which rapidly ex- 
pands into an almost flat disc; roots also proceed from 
the lower surface of the disc. The intervallum is Imm.; 
tabulae from 1mm. to 4mm. apart. The distance from 
centre of cone to edge of fragment is 40mm. Although 
the species resembles Taylor's Coscinoptycha convoluta, | 
the narrow intervallum and closely set tabulae are points 
of distinction which it would be unsafe to ignore. 
Family ACANTHOCYATHIDAE (new family). Figs. 
20, 21, 
This new group is a very interesting one. The speci- 
mens agree with normal Archaeocyathinae in the posses- 
sion of two walls; these are united by a very scanty 
framework of delicate radial rods, similar to the arrange- 
ment seen in Dokidocyathus simplicissimus (Taylor). 
The distinctive feature is that the outer wall, instead of 
consisting of a definite lamina perforated by pores, or of 
This fragment | 
i connected by scattered radial rods. 
a fine spongy mesh, is built up, as it were, of a series of 
fused spicular elements enclosing large open spaces. We 
are not in a position ourselves to discuss the morphologi- 
cal significance of these forms, or their bearing on the 
evolution of Archaeocyathinae and Sponges, but we hope 
that their discovery will be of service to specialists work- 
ing on the phylogeny of both these Phyla. 
Acanthocyathus apertus (new genus and species). Fig. 20. 
Conical tube; intervallum coefficient 5mm : 7mm. Out- 
er wall a very coarse structure, apparently composed of 
fused triradiate spicular elements, enclosing pores from 
1 to 3mm. diameter, the smaller pores being in the smal- 
ler specimens or in those obscured by considerable secon- 
dary silicification; the median limb of each spicular ele- 
ment is prolonged into a spinous process which is directed 
upwards and which projects slightly outwards from the 
general level of the wall (the side parts of the drawing 
fig. 20a rather exaggerate this projection). The inner 
wall consists of a very open network enclosing large 
pores which average 2mm. diameter; the pores are poly- 
gonal (usually hexagonal) with rounded corners, and the 
network consists of round rods about .7mm. diameter. 
The inner and outer walls are connected by scattered ra- 
dial rods, circular in section, anastomosing with the walls 
at rather remote intervals. The drawing fig. 20b shows 
the outer wall and radial connecting elements in radial 
longitudinal section; the central cavity has been ground 
away, exposing the curved surface of the inner wall. The 
species is not very scarce, several specimens having been 
found. | 
Pinacocyathus spicularis (new genus and species). Fig. 21. 
Conical tube; intervallum coefficient 2mm : 2mm. The 
outer wall consists of an open network, the rods forming 
this being about .4mm. diameter; the principal members 
are a series of about 12 vertical rods evenly spaced ar- 
ound the circumference of the wall; these rods, whilst for 
the most part lying at the periphery, dip occasionally a 
short distance inwards; they are united by short cross 
members which more frequently lie horizontally but may 
be inclined; in grinding away the surrounding matrix it 
| was noticed that a few very short branch rods projected 
outwards from the wall, but these projections were for 
‚ the most part lost in the further grinding and etching 
necessary to expose the wall. The inner wall cannot be 
fully seen without damaging the specimen; apparently it 
consists of an open network like that of Acanthocyathus, 
but on a smaller scale, with pores about 1mm. diameter. 
As in the other member of the family the two walls are 
In the lower part of 
the specimen there is an indication of the above mention- 
ed structure passing into an irregular less open network. 
Unfortunately this interesting form is very scarce, only 
one specimen having been found; but it is in excellent 
condition and enables the structure to be defined with 
certainty. y 
Family SPIROCYATHIDAE (Taylor). 
Protopharetra graphica (new species). Fig. 22. 
Conical tube; surface waved by irregular annular bul- 
ges and constrictions, the inner wall following the waves 
of outer wall, thus maintaining a fairly uniform interval- 
