32 RECORDS OF THE ATTSTRALIAN MITSEUM. 



If this fossil be not a Columnaria, but a Favosite, then only one of 

 two explanations is possible. Either the mural pores are confined 

 to the angles of the prismatic tubes, or they are effaced by " com- 

 plete recrystallisation or replacement." The former state could 

 hardly exist without some trace of them being visible in one or 

 another of the tube vertical sections, whilst the coral has not 

 undergone sufficient alteration for the pores to be wholly effaced 

 by the latter process. Had there been the slightest trace of these 

 structures, I should have regarded this coral simply as an aberant 

 form of that large and important family. 



Increase took place by intra-mural gemmation, the interpolation 

 of new tubes produced from the lip of the calicine wall of a pre- 

 existing corallite, of which there are several instances in the 

 longitudinal sections before me. In transverse sections these 

 young tubes are triangular or quadrangular in outline, and 

 situated in the angles between the older. The method of in- 

 crease therefore accords witli that of C. alveolata, Goldf., and 

 differs from that of C. calicina, Nich. 



The main points relied on for the identification of this coral as 

 a Columnaria are (1) the absence of mural pores combined with 

 the general Favositiform structure of the corallites, both points 

 strongly insisted on by those who have written on this group ; 

 (2) the great regularity of the tubes and tabulae, producing at 

 once an entirety that is difficult to put into words, but apparent to 

 any one who has examined authenticated examples of Columnaria, 

 or as it was at one time better known, Favistella; (3) the absence 

 of distinctive features of any other genus at all resemliling it on a 

 cursory examination. Under these circumstances I beg to pro- 

 pose for it the name of Columnaria pauciseptata, in allusion to 

 the limited number of septa present, a point that will now be 

 briefly touched on again. 



Although numerous new species have, more or less perfectly, 

 been described, indeed the late Prof. Ferdinand Roemer* recorded 

 no less than eleven, only about three seem to be at all well known, 

 and these chiefly through the labours of my old friend Prof. AUeyne 

 Nicholson. t They are C. alveolata, Goldf uss (wow Hall, oiec Billings, 

 Rominger, &c.), C. calichia, Nich,, and C. ? halli, Nich. { = C. alveo- 

 lata, Hall, Billings, Rominger, kc, wor* Goldf uss. ) 



In C. alveolata there are in all 24-30 septa, although RomingerJ 

 says 20-30, the primaries sometimes extending to the centre of the 

 calices ; in 0. calicina 28 ; in C. ? halli 20-40, and all quite 



* Lethaea palaeozoica, 1883, Lief. 2, p. 464. 

 t Loc. cit.. pp. 191-202. 



% Report Geol. Survey Michigan, Lower Peninsula, iii., 1876, Pt. 2, p. 91 

 (as C. stellata). 



