the Genus Stenopoi'a, Lo//sda/e. 175 



aiid we shall describe these latter under the name ot" S. 

 australis. 



The character which distinguishes S. ovata, Lonsd.j from 

 all the other species of the genus is the presence of a single 

 large acanthopore at most of the angles of junction of the 

 corallites (PI. III. figs. 1 and 3*). This character is speci- 

 ally noted by Lonsdale (Phys. Descript. N. S. Wales, p. 264), 

 who mentions that there is only one " relatively large tubercle" 

 in " the interspaces between four mouths ;" whereas in S. 

 tasniam'ensis, Lonsd., each tube is encircled by a more or less 

 complete ring of acanthopores. The acantliopores in 8. ovcita 

 are not only few in number, but are of large size, with well- 

 marked thickened walls. The corallites are mostly oval or 

 subpolygonal, their walls completely amalgamated, and with 

 but few and remote tabular. There is no evidence that the 

 tabular were ])erforated by any central aperture. There is 

 also no conclusive evidence as to the existence of mural pores, 

 though there occur here and there in long sections rounded 

 apertures which may very probably be of this nature (PI. III. 

 fig. 2,^;). In the peripheral region of the corallum the coral- 

 lites are furnished with regular and close- set periodical thick- 

 enings (PL III. figs. 2 and 4). 



Locality and Horizon. The Strzeleckian type of -S. ovata 

 was found in the Pernio- Carboniferous rocks of " Mount 

 Wellington, Mount Dromedary, Norfolk Plains, Van Diemen's 

 Land " [Lonsdale). In addition to the above-mentioned, the 

 British Museum contains two examples from Tasmania, pre- 

 sented by Dr. J. Milligan. We have examined these micro- 

 scopically, and find them not to differ essentially from the 

 type-specimen (see PL III. figs. 3 and 4). The corallum, 

 however, is more compressed, the corallites radiate from both 

 sides of a central plane, and the acanthopores are relatively 

 smaller than in the type, while the corallites themselves are 

 also not so large. It would not appear, however, that these 

 differences are of specific importance. [Coll. Brit. Mus.) 



Stenopora australis, Nich. & Eth., Jun. 

 (PL III. figs. 5 and 6.) 



Stenopora ovata, Nicli. & Eth., Jun., Ann, & Mag. Nat. Hist. 1879, 

 vol. vi. p. 274, pi. xiv. tigs. 1-1 c. 



Spec. char. Corallum sublobate or subraassive, of cylin- 



* A tangential section of Sicruqm-a ovata, Lousd., showing the solitary 

 acanthopores, was figured by one of us (Nicholson, Pal. Tab. Corals, 

 p. 281) under the name of 'S'. tasmaniensis, l^ousd. This section was 

 taken, not from the Strzeleckian specimen, but from one of the examples 

 presented to the British Museum by Dr. J. Milligan. 

 ^ 13* 



