132 



HARD Wl CKE' S S CIENCE- G OSS I P. 



often deeply so, but is more generally, in my ex- 

 perience, colourless, except as may be modified by 

 the presence of food, and it usually entirely fills the 

 shell. The pseudopodia are not, as a rule, numerous, 

 rarely more than five or six, and are long, and 

 finger-like. It is not every specimen, however, in 

 which the pseudopodia can be seen projected, but 

 when this is the case they will be found to lengthen 



pear-shaped, hence the name ; other varieties are 

 ovoid and flask-shaped ; occasionally this is com- 

 pressed, and in one well-marked variety the top or 

 fundus of the shell has one or two pointed, conical 

 processes. In some the sand-grains are large, 

 rough and angular, in others most minute ; while 

 other forms have the large and small mixed in 

 varying proportions. One common form here has 



Fig. ^-i.—Dlfftu^ia 

 fyrifor-ntis. 





m. 



WMii 





Fig. loo. — D. acu- 

 minata. 



Fig. 94. — Difflngia fiyi-iforinis. 



Fig. (js-—Diflngia 

 gtobulosa. 



Fig. gj.—D. glob7t/osa. 



Fig. 99. — D. globulosa. 



Fig. 102. — D. acuDiinata. 

 Baloon-shaped individual, 

 with rounded prolongation. 



Fig. 96.— -D. glohu'osa^ 



Fig. 98. — D. globulosa. 



Fig. 103. — D. acuminata. Sand- 

 grains with considerable space 

 between, which is filled uj> 

 with dark brown chitine. 



Fig. loi.— Z>. acuminata. 



Fig. 104. — D. Jirceoiata. 



Fig. lo^.—Difiugia. pyriformis. 

 Specimen with straw-coloured 

 chitinoid basis, sand-grains, 

 rough. In form, it seems to 

 connect this species with Z>. 

 globulosa. This variety has, 

 been discovered since the fore- 

 going was written. 



or shorten, or slowly to move from side to side, 

 almost continuously, while under observation. The 

 mouth of the test is in most cases infeiior and 

 terminal. During the past three months I have 

 found numerous individuals of the genus, belonging 

 to three species. 



Difflugia pyriformis is perhaps the commonest 

 species of the genus, and varies greatly in size and 

 shape. The typical form is narrowly or broadly 



its test of colourless chitinoid membrsne, with a few 

 widely-scattered sand-grains and diatoms. Tha 

 pseudopodia are, in this species, finely granular, and 

 and in all my specimens free from colour. 



Fig. 91, the prevailing form here, of chitinoid 

 membrane, with widely-scattered sand-grains and 

 diatoms. Empty. Fig. 92, another similar one, 

 with sarcode encysted in a brownish ball. Fig.l93 

 large form, [test'- composed entirely of sand-grains. 



