34 Prof. P. M. Duncan on the 
Lophoseris cristata, Ehy., the thickness of the growths being 
variable, but on the whole they are thicker than in Bathyactis 
(Duncan, 1884, Journ. Linn. Soc., Zool. vol. xvii. pp. 304, 
308, 312, pl. xiii.). 
A longitudinal section of Podoseris elongata (Pl. V. fig. 15), 
taken nearly along the plane of the axis, shows in the 
middle numerous septa cut across longitudinally, and showing 
the alternating succession of nodules on their flanks. The 
nodules terminate in oblique processes, which either cross the 
interseptal space and are synapticule, or are curved and 
pointed more or less bluntly and are free at the end. Some 
of these hooks end in the same manner as in P. mamilli- 
formis, and the delicate arched terminations so like those 
described by Pratz in Thamnastrwa may also be seen. Now 
towards the sides of the section the septa are cut across 
obliquely, and close to the edge of the section the flanks of a 
septum are visible on either side of the fossil. The flanks 
show an oblique series of successive ridges, each series upon 
the nodular flank of a septum; and each ridge has been cut 
across parallel with the flank of the septum, for the ridge was 
once continued over the interseptal loculus as an elongate 
synapticulum. The oblique ridges are plainly united here 
and there by delicate processes, which are directed from one 
ridge downwards and slightly obliquely to reach the next 
ridge in downward succession (fig. 16). This feeble develop- 
ment of the endotheca does not resemble that of Cyclolites and 
of some Thamnastreans (Pratz, 1882, Paleontographica, 
vol. xxix. Taf. xiv. figs. 7, 12, 14, “Ueber die verwandtsch. 
Beziehung einiger Korall. mit hauptsiichl. Beriicksicht. ihrer 
Septalstructur ”’). 
The synapticule of the species are often large and are 
usually well developed, appearing in transverse section as 
cross bars, but in vertical sections the structures are elongate 
upon the flanks of the septa. ‘The fossilization of the speci- 
mens is not altogether favourable to the microscopist, but in 
some places the synapticule blend intimately with the septa, 
whilst in others a line of separation can be seen between the 
synapticulee and the sides of the septa on either side. This 
union of the two kinds of synapticule in the species would 
have had considerable significance at the time that Milasche- 
-witsch wrote in ‘ Palxontographica,’ 1875, Korall. d. Natth. 
Schicht. That author found in some genera, Thamnastrea tor 
instance, that the synapticule did not fuse into the septa, but 
that there were junction-lines, indicating that the structures 
were at one time separate. ‘This form of synapticula was 
called a pseudosynapticula. On the other hand, there are 
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