138 G. HEEBEET FOWLER. 



of Radiolai'ia. Iii the liuing membrane I can only identify 

 one layer with certainty, and there is therefore a presumption 

 that this is the homologue of part of tlie central capsule ; but 

 it is softer and less refringent, and it stains more deeply than 

 is usually the case. This lining membrane is clearly traceable 

 as a thick and deeply stained line as far as the upper angle 

 of the mass of " intra-capsular '' circumnuclear protoplasm ; 

 but immediately below the diaphragm it is less stained, 

 thinner, and more refractile. I incline to regard the dia- 

 phragm as a complementary thickening of the central 

 capsule ; in my sections the capsule and diaphragm are never 

 continuous, yet appear to have been so in life, for while the 

 upper angle of the thickened edge of the diaphragm is always 

 tucked neatly into pits of the skeleton (as already mentioned), 

 the lower angle, of varying length and ragged appearance, 

 hangs down into the shrinkage space between capsule and 

 shell [d. i, fig. 8) ; it has every appearance of having been 

 attached to something, probably to the capsule. While, 

 therefore, fig. 8 represents the actual topographical relations 

 seen in longitudinal section, they have been restored in fig. 9 

 to what 1 believe to have been their true positions and 

 connections. 



The iNTRA-CArsDLAR PEOTOPLASM, as is apparent from the 

 various figures, lies immediately below the diaphragm, and 

 has a central aboral swelling due to the nucleus. It is 

 coarsely granular, and above (orally) but not below the 

 nucleus is more or less vacuolated. Laterally it is highly 

 vacuolated, the strands passing outwards to the lining mem- 

 brane, but there is no trace of such strands having been given 

 off below the nucleus. On its upper or diaphragnuitic face 

 it projects in the manner shown in figs. 8, 9, and 10 ; the 

 projections are laminated, and appear to have been inserted 

 into the diaphragm, serving to hold the central mass of 

 protoplasm in place ; they penetrate through the thin refrac- 

 tile central capsule (fig. 10) ; at their bases the protoplasm is 

 closer in texture and more finely granular than elsewhere. I 



