PLATE XIV. 



All the figures in this Plate illustrate the structure of Calcarina. 



Fig. 



1. — Characteristic specimen of the Maltese variety of 

 Calcarina SpengJeri, showing its large club- 

 shaped radiating outgrowths, the tubercles of 

 the central part of its surface, and the septal 

 divisions of the last half turn of the spire, 

 hidden elsewhere by the overgrowth of the 

 intermediate skeleton; magnified 12 dia- 

 meters. 



2.' — Characteristic specimen of the Philippine variety 

 of C. Spengleri, showing the tendency to elon- 

 gation and subdivision of its radiating out- 

 growths; magnified 12 diameters. 



In the succeeding figures, the same letters are 

 used to indicate corresponding parts, as follows : 

 a, a}, a', d", o', interior chambers of successive 

 convolutions ; h, h, b, external surface of the 

 proper walls of the chambers, shown in section 

 at b' b' b'. 



c, c, c, septal pores, constituting the only 

 communication between the chambers. 



d,d,d, intermediate or supplemental skeleton, 

 the progressive increase of the thickness of 

 which in the last convolution is shown at 

 d, d\ d", d\ fig. 4. 



e, e, e, e, summits of the solid tubercles, 

 which are seen in section at e , e , e . 



f, /, /, radiating outgrowths, of which the 

 furrowed surface is shown in fig. 8, whilst 

 their canal-system and its connections are 

 better displayed in fig. 4, where also is shown 

 the diiference in the stage of growth at which 

 the radiating outgrowths /, /, /, /, /', f, re- 



FlG. 



3. 



4. 



5.—; 



6. 



spectively originate from the intermediate 

 skeleton. 



Section of the disk of Calcarina taken through 

 the axis of the spire ; magnified 50 diameters. 



Section of the disk and radiating outgrowths 

 of Calcarina taken through the later whorls 

 (thereby passing over the inner ones) trans- 

 versely to the axis of the spire ; magnified 50 

 diameters. 



Small specimen of Calcarina, of which the spire 

 has detached itself from the disk, and has 

 " run wild ;" magnified 12 diameters. 



-Young specimen of hispid variety of Calcarina ; 

 magnified 30 diameters. 



Portion of the surface of the preceding specimen, 

 more highly magnified, showing that the 

 spines are tubular, being formed around the 

 pseudopodia as they issue from the shell. 



-Ideal representation of Calcarina, hiid open to 

 show the relations of its different parts, the 

 apes of its turbinoid spire being placed down- 

 wards for more convenient display. 



Portion of a section passing through the inter- 

 mediate skeleton in the immediate neigh- 

 bourhood of one of the chambers, showing the 

 free distribution of the canal-system; mag- 

 nified 75 diameters. 

 — Portion of a section passing through the inter- 

 mediate skeleton near the surface of the disk, 

 showing the distribution of the orifices of the 

 canals around the solid cones, transversely di- 

 vided at e, e, e; magnified 75 diameters. 



8. 



9.— 



