Rev. T. B. R. Stebhing — On Calceola sandalina. 61 



central depression being especially prominent. At a little distance 

 from the hinge-line and from the central ridge, several processes 

 stand out conspicuously. These, as well as the hinge-teeth, fit into 

 grooves and depressions in the framework of the calyx, at all stages 

 of growth, as the sections of the calyx demonstrate. The attach- 

 ment of the operculum, by means of these and the interlocking of 

 the ridge and staple, must have been very secure, which will, no 

 doubt, account for its being so much more frequently found in its 

 native position upon the calyx than the operculum of any other 

 rugose fossil. 



We have refrained from applying to Calceola the convenient name 

 of corals, because Lindstrom, following Agassiz, gives reasons of some 

 weight for separating the Eugosa from the true polypes, and 

 conjectures them to be allied rather to the Hydrozoa than to the 

 Anthozoa. They would in that case be a link between the two 

 classes. Quite recently Professor Allman has found reason to suspect 

 that the Hydroida are connected with the Ehizopoda through the 

 Graptolites. Thus link is added to link, and the chain will one day 

 be perfect. But even if the theory, which the finding of these links 

 and the perfecting of this chain helps to corroborate, prove in the end 

 to be utterly untenable — if we see these links only because we wish to 

 see them — if the landscape is coloured green only because we are look- 

 ing at it through spectacles of that colour — still there is this immense 

 advantage in a new and attractive hypothesis over an old unsub- 

 stantiated prejudice, that while the latter keeps our eyes shut or 

 staring vacantly with blank gaze, the former opens them, quickens 

 them to study and research, enables them to see the landscape and 

 many of its beauties even if wrongly coloured, and, for one spectre 

 of the imagination which it may call up, shows them a thousand 

 useful realities. 



EXPLANATION OF PLATE V. 



Calceola sandalina^ Lamarck, Devonian, Eifel. 



Fig. 1. Section parallel to operculum, showing septa. 



Fig. \a. The same enlarged. 



Fig. 2. Vertical section through the operculum and calyx at right-angles to the 



hinge-line. 

 Fig. 2a. The same enlarged. 



Fig. 3. Flat side of calyx, showing the epitheca with its median ridge. 

 Fig. 3ffl. Front view of same specimen, showing the cavity of the calyx. 

 Fig. 35. Side view of same. 



Fig. 4. Section through operculum and calyx, parallel to the hinge -line. 



Fig. 6. Young specimen, showing the large median septum. 



Fig. 6. Flat side of calyx ; epitheca worn away. 



Fig. 7. Exterior of operculum. 



Fig. 8. Interior of same. 8a. Operculum in profile. 



