194 TABULATE CORALS. 



type of a special family, to which the name of Cohminariadts 

 may be applied. 



Professor Verrill (Amer. Journ. Sci. and Arts, sen 3, vol. iii. 

 p. 191, 1872) has drawn attention to the resemblance between 

 Coliimnaria and certain of the Astr^eans (such as CailastrcBO), 

 and he has expressed the opinion that the genus, " if not actu- 

 ally a member of the AstrcsidcE, should at least be referred to 

 a family very near that group." There is much to be said for 

 this view, but considering the less regular development of the 

 septal apparatus in Cobunnaria, and its apparent want of any 

 endothecal dissepiments (apart from the " tabula;," if these 

 structures are regarded as dissepimental), I think it safer in 

 the meanwhile to leave the position of the genus an open 

 question. 



The typical species of the genus Columnaria are C. alvcolata, 

 Gold, {lion M'Coy and Hall), C. GotJilandka, E. and H., and 

 C. calicina, Nich., all of which are Silurian in their distribution. 

 The first and last of these are principally Lower Silurian, and 

 the Upper Silurian C. Gothlandica, E. and H. (Pol. Foss. des 

 Terr. Pal., p. 309, PI. XIV., figs. 2 and 2 a), would appear to 

 be hardly separable specifically from C. alveolata, Goldf 



There remains the Silurian coral which has been described 

 by Hall, M'Coy, and other observers under the name of Colum- 

 naria alveolata^ Goldf, with which we may possibly associate 

 certain other forms (e.g., C. erratica, Billings). This form I 

 shall briefly consider under the name of Cobcmnaida (?) Halli, 

 mihi, though I very greatly doubt if it be really referable to the 

 genus CobLinnaria of Goldfuss. As to the other forms which 

 have been included by various writers under the genus Cobim- 

 naria, I can say nothing, as I have not had the opportunity of 

 examining actual specimens. 



