﻿Notes on Fossils from Prince Charles Foreland. 153 



very thin in the axial region; and from that point of their 

 course where they begin to be perpendicular to the surface, 

 they are suddenly thickened to a considerable degree, and 

 exhibit the moniliform structure characteristic of the genus. 

 The swellings, separated by thin intervals, are oval in shape, 

 and not numerous. In one case it has been possible to 

 observe the divisional line between adjoining zosecia. 



Although a number of thin longitudinal sections of both 

 axial and mature regions has been prepared, on none has it 

 been possible to observe the presence of diaphragms ; and as 

 the specimens are all in a very good state of preservation, it 

 follows that the absence of diaphragms cannot be attributed 

 to the action of weathering, but that it is one of the specific 

 characters of this Stenopora. 



Tangential sections near the periphery show the presence 

 of large acanthopores at most of the junction angles between 

 adjoining zo?ecia. The structure of the concentric lamellae, 

 of dark sclerenchyma, and the minute axial canal of the 

 acanthopores, are well preserved. An immature zosecium 

 generally accompanies each of the larger ones. 



Remarks. — In this species the branches are always simple, 

 that is, never formed of successive colonies in concentric 

 layers. In one particular specimen the colony is seen to 

 envelop a foreign body, probably a Serpula, which occupies 

 the middle of the longer axis of the colony. According to 

 Messrs Waagen and Wenzel,i this phenomenon is of frequent 

 occurrence in colonies of Batostomella columnaris (Schloth.) 

 [Geinitzella aicctt], and was erroneously considered by 

 Dybowski^ to be an essential character of the genus 

 " Stenopora.'' These authors give excellent figures of thin 

 sections of Batostomella columnaris, proving the undoubtedly 

 foreign nature of these enveloped bodies (the "Axenrohr " of 

 Dybowski). 



Affinities and Differences. — It is an easy matter to compare 

 the present species with those described of late years by 

 authors who have made use of modern methods of investiga- 

 tion. The absence of diaphragms distinguishes it from all 



^ Pal. Indica, Salt Range Fossils, part 6, "Coelenterata," p. 880. 



- Verhandl. russ. Kais. min. Gesel., Zweite Ser., 12 Band, 1877, p. 65. 



