APROPHYLLUM HALLENSE AND LITHOSTROTION. 65 



Note. — The stout well-formed columella and the intra- 

 thecal area crowded with sections of tabellse. Compare 

 this with figs. 4, 4a, 4b, and 4c, British form, in which the 

 columella is weakly developed or absent and few inter- 

 sections of tabulae. 

 Fig. la. The same, natural size. 



Fig. 2. Lithostrotion arundineum Eth. fil. Topotype. Transverse 



section, same locality. (D4.) x 2. 

 Fig. 2a. The same, natural size. 



Fig. 3. Lithostrotion stanvellense Eth. fil. Topotype. Longitu- 

 dinal section. (D 12.) x 2. 

 This section illustrates the most striking difference 

 between Australian and British types. Compare the 

 stout columella and small arched tabellse with the more 

 slender columella and simple tabula in Fig. 6, a specimen 

 from the North of England. 

 Figs 4, 4a, 4b, 4c. Lithostrotion martini Ed. &, H. Transverse 

 section, Narrowdale, Derbyshire, England, x 2. 

 Corallites from same corallum, see note on Fig. 1. 

 Fig. 5. Lithostrotion martini. Transverse section, Alston, 

 Cumberland, England, x 2. 

 This form closely approaches the Australian type in its 

 stout columella and numerous inter-sections of tabulae or 

 tabellse. 

 Fig. 6. Lithostrotion martini. Longitudinal section, Settle, 

 Yorkshire, England. See note on fig. 3. 



Plate V. 



Lithostrotion — Lithostrotion columnare. 

 Fig. 1. Lithostrotion columnare Eth. fil. Topotype. Transverse 



section, Lion Creek, Stanwell, near Rockhampton, 



Queensland. (D 13.) Natural size. 

 Fig. la. The same x 2. 



Fig. 2. The same. Transverse section. C — columella, E = epitheca 

 T = theca. 



E— July 7, 1820. 



