318 Mr. H. J. Carter on Squamulina scopula, 



to the purpose of nutrition and for the formation of its test 

 respectively. 



lleturning, now, to the pseudo-septal division of the pedestal, 

 let us consider for a moment this structure with reference to 

 its comparative morphology. 



When the specimens of Srjiiamulina scopula are dried, they 

 are very prone to fall otf from their attachment to the fucus ; 

 and then they invariably leave the bottom or disk of the pe- 

 destal adherent to the former — which at once enables us to see 

 the disk on the fucus (figs, 6 & 7), and the vault of the convex 

 pedestal still connected with the broken-off column (fig, 8 a). 



If we first look at the disk adhering to the fucus (figs. 6 & 7), 

 we shall observe that it is more or less white, being composed 

 of the same material as the test, and presenting a more or less 

 uneven ring, from which several processes of unequal length 

 radiate inwards. Five or six, but generally five, of these, as 

 before stated, are much more developed than the rest ; con- 

 stricted towards the circumference and inflated towards the 

 centre of the disk, which they do not reach, but leave, as also 

 before stated, a central area, which forms, with the interspaces 

 between the radii, a single common chamber, continuous, 

 through the aperture of the summit of the pedestal (fig, 5«), 

 with the general cavity of the column. The interspaces of the 

 disk are more chitinous perhaps than arenaceous j that is to 

 say, the test is not near so thick here as in other parts. 



Turning to the corresponding portion of the pedestal still at- 

 tached to the column (figs, 8 & 9), we observe that these radiated 

 portions of the disk belong to as many pseudo-septal divisions 

 which, extending upwards, at last lose themselves upon the 

 dome of the pedestal, near the margin of its aperture, and that, 

 in the dried state, a contracted mass of dark brown sarcode {a) 

 at this point presents, in its still lobed form (fig, 9 a), the indica- 

 tion of its once (when living) having occupied the interspaces 

 between the septal divisions of the pedestal. 



Now this radiated disk undoubtedly has very much the 

 appearance of the radiated septa of a coral-polype ; but it has 

 a still nearer affinity to the septal divisions of a nautiloid 

 foraminiferous test ; and when we compare the whole structure 

 of the pedestal with the latter, we cannot help seeing that the 

 septal divisions are homologous with the septa of a nautiloid 

 foraminiferous test, and that the central area corresponds 

 with the initial or primary cell of a nautiloid individual, 

 which, on being prolonged upwards, in Squamulina scopula, 

 dcvelopes a column at the expense of the spire. 



Following uj) this view, I by chance found a pedestal alone j 

 which I have mounted in balsam and drawn as one of the 



