74 Mr. W. Saville Keut on the Foraminiferal 



attenuate contour of the Jersey examples is due, to some 

 extent, to the greater rapidity of the currents to which they 

 are exposed, may be submitted as a reasonable conjecture; but 

 it is at the same time certain that we have here an organism 

 tied down by no hard and fast lines of specific immutability, 

 but one inheriting a most extensive range of morphological 

 variation. Several plates might with the greatest ease be 

 occupied in the delineation of the innumerable polymorphic 

 aspects presented by the variously constructed domicile of 

 this undoubtedly clever little artificer ; but a few figures only, 

 to which reference may now be made, suffice for the repre- 

 sentation of the more remarkable of these. 



The form represented by fig. 6 of PL IV. may be ac- 

 cepted as one of the more simple expressions of this specific 

 type as met with upon the Jersey coast, and as the one that ap- 

 proximates most closely to the type upon which Dr. Bowerbank 

 originally founded the genus Haliphysema. The projecting 

 spicules artificially incorporated in the test of this specimen 

 are certainly not so numerous as in that type form, and are 

 disposed with greater irregularity upon its surface. These 

 spicules are indeed, as in all the other examples here deli- 

 neated, mostly replaced by a suitable building-material 

 more readily and abundantly accessible, consisting of the 

 angular quartz granules of every size and form derived from the 

 disintegration of the adjacent granite. This slight variation 

 in the composition and arrangement of the building-constituents 

 affords, however, no sound basis for specific discrimination, 

 representing in this case a mere adaptation to circumstances, 

 and demonstrating the capacity of the little architect to, as it 

 were, make his bricks without straw, and to turn to equally 

 good account whatever material, sufficiently adapted to the 

 purpose, may fall within his reach. Not unfrequently speci- 

 mens occur most nearly resembling the form just referred 

 to, but in which the wider distal region is not reflected to one 

 side, but presents a simply short, erect, and clavate outline, 

 corresponding, under these circumstances, with a small ex- 

 ample of Mr. Carter's typical SquamuUna scopula included in 

 the slide placed by him at my disposal. A third modifica- 

 tion of this same variety is likewise encountered, in which 

 the more inflated distal portion assumes a perfectly globular 

 outline. This variation, with its short slender pedicle and 

 terminal chevaux de frise of radiating spicula, presents an 

 aspect so closely coinciding in external contour with Prof. 

 Haeckel's Haliphysema echinoides (Biolog. Stud. p. 186, 

 pi. X. fig. 127) that, making due allowance for the variation 

 in the spicular armature— a feature entirely dependent on the 



