AMPHITREMA WEIGHTIANUM. 151 



The nucleus, unless it be artificially coloured, is 

 difficult to distinguish on account of the opacity of the 

 test and the number of green Chorella-cells contained 

 in the plasma. The tufts of pseudopodia extending 

 from the two apertures are usually unequal in the size 

 and number of filaments. 



In the peat deposits of Clare Island, Mayo, several 

 tests were found of which the broad and narrow side 

 views are shown in PL LVII, fig. 8. The extraneous 

 grains of silica, diatoms, etc., which no doubt were 

 originally attached to them, have, during the thousands 

 of years which have elapsed since they were occupied 

 by the living animal, become detached, the mem- 

 branous coverings alone being left. 



3. Amphitrema stenostoma Nuesslin. 

 (Plate LVII, figs. 9 and 10, and fig. 159 in text.) 



Amphitrema stenostoma 



NUESSLIN in Zeits. wiss. Zool. XL (1884), p. 717, pi. xxxvi, ff. 7-14. 

 BLOCHMANN Mikr. Thierw. Siisswass. (1886), p. 16, pi. ii, f . 37 ; ed. 2 



(1895), p. 20, pi. ii, f. 30. 

 PENARD Faune Rhiz. Loman (1902), pp. 527-538, 3 figs. ; Sarcodines 



in Cat. Invert. Suisse (1905), p. 112 ; in Brit. Antarct. Exped. I 



(1911), pp. 220, 223. 



CASH in Jm. Linn. Soc., Zool. XXIX (1904), p. 219. 

 AVERINTZEFF in Trudui S.-Peterb. Obshch. XXXVI, n (1906), p. 321. 

 SCHOUTEDEN in Ann. Biol. lacustre, I (1906), p. 373. 

 EVANS in Proc. R. Phys. Soc. Edinb. XVII (1907), table 1. 

 HOPKINSON in Irish Natur. 1910, p. 3. 

 BROWN in Ann. Scott. Nat. Hist. 1911, p. 229 ; in Jrn. Linn. Soc., 



Zool. XXXII (1911), p. 84 ; in Naturalist, 1912, pp. 181, 182 ; in 



Scott. Natur. 1913, p. 187. 

 WAILES & PENARD in Proc. R. Irish Acad. XXXI, LXV (1911), pp. 14, 



20, 61. 

 WAILES in Scott. Natur. 1912, p. 60 ; in Jm. Linn. Soc., Zool. XXXII 



(1912), pp. 126, 153 ; in Naturalist, 1913, p. 187. 



Test similar to that of the preceding species but 

 more closely covered with grains of quartz and various 

 extraneous particles ; the apertures destitute of any 

 collar, usually surrounded by numerous particles and 

 collections of reserve materials ; nucleus, plasma, and 

 pseudopodia similar to those of the preceding species. 



