HA RD WICKE'S SCIENCE- G OS SIP, 



245 



diatoms and other minute algse can be seen in various 

 stages of digestion. The pseudopodia are exces- 

 sively delicate, and require a nice adjustment both 

 of focus and of the light, to clearly distinguish them. 

 The artist has drawn the pseudopodia too dark. 

 In all cases, the sarcode entirely fills up the delicate, 

 membranous shell. The figures will show the general 

 arrangement of the pseudopodia, which are almost 

 constantly moving, though sluggishly, from side to 

 side, or lengthening and shortening in the same slow, 

 deliberate manner, A large nucleus is generally 

 visible. My specimens were procured in great num- 

 bers, from the ooze of a clear pond. Although there 

 was a constant though slow movement of the pseudo- 

 pods, I never noticed any of the animals to move from 



Fig. 198.— Pamphagus. 



Fig. 199. — Pamphagus. 



\ 





Fig. 200.— Pamphagus. 



Fig. 201.— Pamphagus. Fig. 202. — Pseudodifflugia gracilis. 



the position in which they were first seen under the 

 microscope ; it is quite possible, however, that in 

 summer they may show a greater activity in this 

 respect. Like all other Rhizopods, they vary greatly 

 in size, but the majority of my specimens averaged 

 about the 3^5 of an inch. 



The genus Pseudodifflugia differs from Pamphagus 

 only in the fact, that its chitinoid shell is incor- 

 porated or encrusted with sand-grains or dirt ; in 

 other words, it has the test of a Difflugia, but the 

 delicate, filose, pseudopods of Pamphagus, There is 

 only one species, P. gracilis, and in this the test is 

 more or less void, with the mouth at the narrow 



pole ; it is of various shades of brown, approaching 

 to black. All my specimens were much more active 

 than those of Pamphagus, among which they were 

 numerous ; indeed, many of them would have been 

 quite overlooked, had it not been for the bobbing 

 about of the shell, as they were so very much like an 

 ^SS^'^g^tion of flocculent dirt. I think it very pro- 

 bable that the form is much more common than 

 supposed, but that its inconspicuous character causes 

 it to be overlooked ; or if seen, to be confounded 

 with a minute Difflugia, 



Fig. 198. ':imzX\. %^tQvca^T\. oi Pamphagtis gracilis. 



Fig, 203. — Cyphoderia ampulla. 



Fig. 204.— Cyphoderia, ' 



Fig. 205. — Cyphoderia devouring Conferva. 



Figs, 199 and 200, Larger forms with extended 

 pseudopodia ; sarcode granular with yellow patches. 



Fig. 201. Side view of another, showing neck, and 

 the extension of the pseudopodia through the mouth. 



Fig, 202. Pseudodifflugia gracilis, with test of 

 brownish dirt. 



Cyphoderia amptilla is another Rhizopod, not un- 

 common in this district. I have found it in fair 

 numbers in one clear pool, in several wells, and 

 amongst Sphagnum ; from the latter, the specimens 

 have been larger, and, I think, more active. The 

 test of Cyphoderia is very elegant from its graceful 

 curves, and its minute pitting in all its varieties. It 



