34 Prof. P. M. Duncan on the 



Lophoseris crisiata, Elir., 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, pi. xiii.). 



A longitudinal section of Podoseris elonqata (Pi. 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 synapticulas, 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. mamiUi- 

 foo'fm's, and the delicate arched terminations so like those 

 described by Pratz in Thamnastnea 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 iiank of the septum, for the ridge was 

 once continued over the interseptal loculus as an elongate 

 synapticulum. The oblique ridges are plainly united liere 

 and there by delicate processes, which are directed from one 

 ridge downwards and slightly obliquely to reach tiie next 

 ridge in downward succession (fig. 16). This feeble develop- 

 ment of the cndotheca does not resemble that of C // dol ites Siud 

 of some Thamnastrteans (Pratz, 1882, Palaiontographica, 

 vol. xxix. Taf. xiv. figs. 7, 12, 14, " Ueber die verwandtsch. 

 Beziehung einiger Korall. mit hauptsiichl. Beiilcksicht. ihrer 

 Septalstructur "). 



The synapticuljfi 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 synapticulas blend intimately with the septa, 

 whilst in others a line of separation can be seen between the 

 synapticulse and the sides of the septa on either side. This 

 union of the two kinds of synapticula^ in tlie species would 

 have had considerable significance at the time that Milasche- 

 witscli wrote in ' Palasontographica,' 1875, Korall. d. N^atth. 

 Schicht. That author found in some genera, Tkamnastnea for 

 instance, that the synapticulte 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 



