168 PBOF. W. N. BENSON AND DE. S. SMITH ON [vol. lxxix, 



tabulae are flat or saucer-shaped instead of conical. Such, forma 

 are usually described as Liphyphyllum, following Lonsdale l ;. 

 nevertheless, both the ' Lithostrotion ' and the ' Dipliyphyllum ' 

 types of corallite may be found within the same corallum. 



The characters of this well-known genus are here re-defined, 

 merely in order to curtail the description of the Australian species, 

 and to render a comparison between them and the British clearer 

 and more concise. 



Species of Lithostrotion described from the 

 Burindi Series. 



Two fasciculate and one massive species of ' Lithostrotion'' ' 2 and 

 a ' Lfiphyphyllum'' 2&3 have been recorded from the Burindi Series.. 

 The fasciculate specimens of Lithostrotion have been identified 4 

 with species described by Robert Etheridge fil. 5 from beds in 

 Queensland — the Star Series, in all probability stratigraphically 

 equivalent to the Burindi Series : namely, L. arundineum Ethe- 

 ridge fil. audi, stanvellense Etheridge fil. The massive form was 

 recorded by one of us (loc. cit.) as L. columnare Etheridge fil. ; 

 but the material was not available for later detailed examination. 



The following remarks are based upon the examination of 

 material from both New South Wales and Queensland. 



L: arundineum is fasciculate. The corallite attains a diameter 

 of 5 mm. and the intrathecal region of the corallite a diameter of 

 4 mm. The septa usually number 18 to 20 in each cycle. The 

 species, in these respects, agrees very closely with L. irregulare 

 Phillips. 



L. stanvellense is fasciculate ; the diameter of the corallite = 

 9 to 11 mm. ; the diameter of the intrathecal region = 7 to 8 mm. 

 Number of septa in each cycle, 24 to 30. Species comparable with 

 L. martini Edwards & Haime. 



L. columnare is massive ; diameter of corallite = about 15 mm.. 

 or more ; diameter of intrathecal region = 5 mm. 6 Number of" 

 septa in each cycle, about 24. Species comparable with L. basalti- 

 forme auctt. 



1 ' Description of some Palaeozoic Corals of Russia ' : see R. I. Murchison 

 & others, ' The Geology of Russia in Europe & the Ural Mountains ' vol. i 

 (1845) pp. 602 et seqq. 



2 W. N. Benson, ' A Census & Index of the Lower Carboniferous Burindi 

 Fauna ' Rec. Geol. Surv. N.S.W. vol. x (1921) pp. 32 & 33. 



3 W. N. Benson & W. S. Dun, ' The Geology & Petrology of the Great 

 Serpentine-Belt of New South Wales ' Proc. Linn. Soc. N.S.W. vol. xlv (1920) 

 p. 341. 



4 S. Smith, ' On Aphrophyllum hallense gen. et sp. nov. & Lithostrotion 

 from the Neighbourhood of Bingara (N.S.W.) ' Journ. & Proc. Roy. Soc. 

 N.S.W. vol. liv (1920) pp. 56-63 & pis. iii-v. 



5 R. Etheridge fil., ' Corals from the Coral Limestone of Lion Creek, 

 Stanwell, near Rockhampton ' Geol. Surv. Queensl. Bull. 12 (1900) pp. 10-20- 

 & pi. i, figs. 1, 3, 4, 5, pi. ii. figs. 1-8. 



6 The extrathecal region is always wider in ' massive ' species than in; 

 fasciralate ; see Q. J. G. S. vol. lxxii (1916-17) p. 282. 



