Bev. T. R. R. Stebbing — On Calceola sandalina. 59 



the same general shape, while it was not known that any of the Eugosa 

 had lids or opercula. Moreover, in most species of Zoantharia, when the 

 calyx or cup is simple, that is, standing alone, its shape is approxi- 

 mately circular, whereas Calceola sandalina has one surface flattened, 

 forming the sole of the slipper. A wrinkle running down the 

 middle of this surface from the hinge to the apex, or pointed toe 

 of the slipper, helped the deception, seeing that several Brachiopods 

 have a narrow delta-shaped prominence in what seemed a corre- 

 sponding situation on the ventral valve. 



According to Lindstrom it was Guettard who first made known the 

 occurrence of an operculum among the Zoantharia rugosa. In all pro- 

 bability then G-uettard is a very good observer, for, unless fortune be 

 wonderfully kind, it requires excellent eyes to be able to see a thing 

 through a heap of prepossessions. Milne-Edwards had perhaps an 

 advantage in classifying Goniophyllum, in that, as it appears from 

 his silence, he did not know of the existence of its operculum.^ Thus 

 he had one temptation the less to class it among the Brachiopoda. 

 Since then several of the Eugosa have been determined to be 

 operculiferous, in particular Goniophyllum, Calceola sandalina, and 

 Calceola Gotlandica, which last Lindstrom re-names Bhizophyllum 

 Gotlandicum, pointing out that its vesicular structure makes it a link 

 between the Cyathophyllidee and Cystiphyllidse. By this structure 

 and its rootlets, and possibly by its gemmation, it differs from 

 Calceola sandalina, which in all other respects it closely resembles. 

 But the rootlets, the vesicular structure, the mode of gemmation, all 

 bind Bhizophyllum to the Eugosa ; and in whatever section Bhizo- 

 phyllum stands, undoubtedly Calceola must- stand with it. The 

 rootlets are common to both the families above mentioned, so is the 

 vesicular structure, some specimens of Cyathophyllum being so 

 strongly vesiculose as to suggest a doubt whether the erection of the 

 Cystiphyllidse into a separate family be tenable. We all like sharp 

 definition when it can be had, and disapprove, in a general way, of a 

 creature which we cannot make out to be either fish, flesh, fowl, or 

 good red herring; so that it is natural to feel a little spite against 

 fossils of so slippery a nature that they come to us at first looking 

 like Brachiopoda, and then prove to be Zoanthariae, but so ill-disposed 

 that they break up our family arrangements, separating what we had 

 agreed to combine, and combining what we had agreed to separate. 

 Nevertheless the supporters of a certain theory have a grim satis- 

 faction when the discovery of new forms or improved classification 

 links together species and genera, or even higher divisions, in a 

 manner entirely consistent with the hypothesis of a common origin 

 for large branches of the animal kingdom, but repugnant to the 

 other hypothesis of an abrupt creation in accordance with definite 

 types. 



^ It may be doubted whether the aduU Goniophyllum pyramidale really had an 

 operculum after all ! It is true Lindstrom figures a detached operculum which he 

 refers to this genus (see Geol. Mag. 1866, Vol. III. PI. XIV. Figs. 6 and 7, p. 356), 

 but out of several hundred specimens, obtained wilhiu the last five years from Dudley, 

 not one possessed an operculum. — Edit. Geol. Mag. 



