410 Lindstrbm — On Zoantharia Rugosa. 



when they adhered to other bodies. In some species (Calceola, 

 Goniophyllum, Hallia calceoloides) , this flat side remained, while in 

 others it soon became convex, and the shell assumed a cylindrical 

 shape, when it began to raise itself freely above its point of attach- 

 ment.^ If we now look at the interior cavity of Calceola sanda- 

 lina, all likeness with the BracMopoda at once ceases. We there 

 again see a groove in the bottom completely coinciding in size and 

 position with that of Goniophyllum, other Calceolce, Ompliijma, etc. 

 Opposite this pit is the middle septum, completely homologous with 

 that in the species just named, and environed by smaller ones. The 

 operculum agrees perfectly with that of Goniopliyllum and G. Got- 

 landica in its elements, but modified in details. There is a middle 

 ridge on its interior side formed in the same manner, and above it 

 the small oval pit enclosed by two lateral processes, the same stri^ 

 on the sides curved towards the middle ridge ; indeed, all those 

 points of structure are common to these species. The structure 

 of the shell by no means resembles that so characteristic of the 

 BracJiiopoda, which is prismatic and often perforated by small pores. 

 It consists of thin, funnel-shaped layers, as in so many of the 

 Bugoso.. In consequence of all these affinities with the Z. rugosa 

 (both with those that are provided with an operculum, and those 

 without), Calceola sandalina must be removed from the class 

 BracMopoda, and henceforth considered as one of the Bugosa.'^ 



But if we again compare C. sandalina with C. Gotlandica and 

 Tennesseensis, we discover more than specific differences, and it seems 

 impossible to retain them any longer in the same genus. C. sanda- 

 lina is distinguished by its more regular shape, and by the absence of 

 all rootlets. The sej^ta are also more regular and complete, the 

 middle septum of the flat wall larger, and the bottom is void of all 

 vesiculee. It seems, moreover, not to have propagated by means of 

 buds.^ The figures of Calceola sandalina, which have been giveh in 

 various pal^ontological works, vary much from my description. 

 This is caused by their having been drawn from weathered specimens. 

 The middle septum is then, as it were, decomposed into its elements 

 leaving two lamellae with a deep groove between them. In others 

 only the uppermost part of the septum is left, with a depression or 

 groove beneath. This is the case in weathered specimens of Gonio- 

 phyllum and Calceola sandalina. The punctated lines between the 

 septa of the second order have, as in the other species, been occa- 

 sioned by the weathering of the small teeth of the septa. It is easy 

 to prove the existence of a true septum in the middle, and not a 



1 A Cystiphyllmn, having a shape between a cylinder and a four-sided prism, 

 comes near to the pyramidical form of Goniophyllum. 



2 Sir Charles Lyell, in the sixth edition of his Manual, says (p. 537) that some 

 naturalists have lately referred C. sandalina to a coral. " They suppose it to be an 

 abnormal form of the order Z. rugosa, differing from all other corals in being furnished 

 ■with a strong operculum." In this opinion 1 cannot join, because, as I have en- 

 deavoured to show, I do not consider Calceola sandalina, or the other Rugosa, as 

 corals. Neither is the C. sandalina an abnormal form of its order. 



^ The best figm-es of G. sandalina are in all probability those seen in Goldfuss's 

 Petrefacta Germaniee, vol. ii., pi, clxi. fig. 1. 



