236 Mr. A. Hancock on the Esccavating Sponges. 



ing from Cliona in the fact that they are usually arranged either 

 spirally or cyclically, and do not assume a regularly branched 

 character ; but nevertheless the arrangement of the lobes in the 

 two groups is occasionally very similar. 



If we remove the testaceous covering of any of the Rotalina, 

 and suppose the sarcode unrolled, we shall see at once how 

 much the structure resembles a branch of Cliona corallinoideSj 

 for instance : both are composed of a series of nodules or lobes 

 united by very short constricted stems. The sarcode of Nodo- 

 saria, however, requires no unrolling to exhibit this relation- 

 ship; but it will be best understood on comparing the figures 

 of the various species illustrating my paper before referred to 

 on the excavating Sponges with the many instructive figures of 

 the sarcode given in Dr. Carpenter^s ' Introduction to the Study 

 of the Foraminifera/ published by the Ray Society. On exa- 

 mining the representation of the cast of the chambers of Orbi- 

 toides Fosteri therein given from Ehrenberg*, it is seen that the 

 chambers or lobes are arranged cyclically ; but in a radial direc- 

 tion they assume a branched distribution ; and if we trace the 

 connexion of the lobes (PL VII. fig. 8) from the centre to the 

 circumference, beginning wdth those next the primordial lobe, 

 we can easily observe not merely that they are connected into 

 branches by delicate stems, but that these branches divide di- 

 chotomously and anastomose very much in the same manner as 

 do those of Cliona. Indeed the structure appears to be essen- 

 tially the same in both, differing only in the fact that in Orbi- 

 tvides the lobes, in addition to a branched, partake of a cyclical 

 arrangement. 



Should this similarity in the structure of the Foraminifera 

 and Cliona be anything more than a mere vague analogy, spi- 

 cula might be expected to occur in some species of the former; 

 and accordingly such seems to be the case. A few years ago 

 Dr. J. E. Gray discovered spicula in a new generic form desig- 

 nated by him Carpenteria f ; and at the time he commented on 

 the fact as proving the connexion supposed to exist between the 

 Foraminifera and Porifera : it is possible, however, that these 

 spicules may be parasitic. It would therefore seem likely that 

 there is something real in the relationship pointed out ; and, 

 indeed, when we recollect that the Cliona are among the lower- 

 organized Sponges, their intimate connexion with the Foramini- 

 fera is what might be looked for. 



I shall now close these few remarks with emended descriptions 

 of the spicula of the British Cliona>j and with full descriptions 



* PI. 22. fig. 2.. 



t Proceedings of the Zoological Society, pt. xxvi. p. 266, April 27, 1858, 



