178 Dr. H. A, Nicholson a7id Mr. R. Etheridge, Jun., on 



only highly mineralized, but they mostly exhibit in thin sec- 

 tions certain anomalous features which need not be further 

 particularized here, but which render their structure in many 

 respects very diiScult of interpretation. In order to show the 

 peculiar state of preservation here referred to, we have figured 

 some of the sections precisely as they anpear under the micro- 

 scope (PI. III. figs. 5-8). 



Locality and Formation. Permo-Carboniferous, Coral Creek, 

 Bo wen-River Coal-field, Queensland. {Coll. Geol. Survey, 

 Queensland, and Brit. Mas.) 



Stenopora tasmaniensis, Lonsdale. (PI. III. figs. 9-12.) 



Stenojwra tasjnaniensis, Lonsdale, in Darwin's Geol. Obs. Vole. Islands, 

 p. 161 (1844) ; find in Strzelecki's Phys. Descript. N. S. Wales, p. 262, 

 pi. Yiii. tigs. 2-2 c (1845). 



(Non Stenopora tasmaniensis, Nicli. Pal. Tab. Corals, p. 281 (1879), 

 figure only.) 



Spec. char. Corallum branched, the cylindrical stems vary- 

 ing from 1 to 1| centim. in diameter; rarely in the form of 

 a thin flattened frond. In the branched specimens the coral- 

 lites radiate from the central axis, the peripheral portion of 

 the corallum (in which the tubes are specially thickened) 

 being very narrow. In frondescent specimens the corallites 

 diverge nearly rectangularly from both sides of a median 

 plane, and the axial region of the corallum is non-existent. 

 The annulations or periodical thickenings of the walls in the 

 peripheral region are very wade and run into one another, 

 thus becoming comparatively indistinct. The corallites are 

 oval, about ^ millim. in their long diameter, arranged in 

 slightly oblique rows, with their long axes corresponding 

 with the long axis of the corallum. Acanthopores are very 

 numerous, arranged like the tubes in slightly oblique longi- 

 tudinal rows, and forming a more or less complete ring round 

 each corallite. Superficially the acanthopores appear as rows 

 of small tubercles or minute apertures surrounding the mouths 

 of the tubes. Tabulas are very sparingly developed and 

 appear in long sections to be complete ; but the mouths of the 

 tubes are sometimes closed by perforated tabula^,. Mural pores 

 not detected. 



Ohs. This species is at once recognized by its long oval 

 calices arranged in oblique longitudinal rows and by the 

 similarly arranged rows of acanthopores (PL III. figs. 9 and 

 11). It agrees with ;S'. ovata in the complete amalgamation 

 of the walls of the corallites, which show no traces of the 

 primordial wall. Transverse sections of the cylindrical speci- 

 mens are remarkable for the o-veat width of the axial reerion 



