486 PROFESSOR E. RAY LANKESTER. 



The staining with picro-carmine did not affect the concre- 

 tions, but was taken very strongly by the whole contents of 

 the nuclear cyst. 



The cuticle. — Iodine was applied to one specimen, in order 

 to ascertain the presence or absence of starch. No starch 

 was found, but the iodine brought out a very remarkable 

 structure on the surface of the organism, which certainly 

 must be held to indicate the existence of a cuticular pellicle. 

 The structure in question consisted of exceedingly fine 

 granules (fig. 7), which, when a portion of the margin of 

 the body was focussed, so as to give an optical section, had 

 the appearance represented in fig. 6. The regular disc- 

 like form of Lithamoeba and the peculiar character of its 

 hernia-like pseudopodia are quite in accordance with the 

 existence of a cuticular pellicle, which must be inferred 

 from the punctate structure rendered evident by iodine. 

 The cuticle of Lithamceba is not a highly-developed one, 

 like those of Atnphizonella, or of Amphitrema, which leave 

 portions of the body unprotected, whence the naked proto- 

 plasm can be extruded, but it is of a delicate and easily 

 ruptured consistency, bursting, as it were, sometimes at one 

 point, sometimes at another, in order to allow the con- 

 tained protoplasm nakedly to expose itself in a hernia-like 

 excrescence. 



Pseudopodia. — The hernia-like pseudopodia of the same 

 specimen as that drawn in fig. 1 are seen in fig. 2, the or- 

 ganism being represented in a state of activity. The extrusion 

 of these masses seems to begin with a minute rupture of the 

 cuticle. Through the orifice thus produced the fluid pro- 

 toplasm exudes in a spherical form, and as it increases in 

 quantity the rupture of the cuticle is increased, whilst con- 

 cretions from the more central portion of the disc-like body 

 flow into the enlarging lobe. With great rapidity the whole 

 extrusion now appears to fuse once more with the disc, and 

 a new rupture and extrusion takes place at another point of 

 the margin. A new cuticular pellicle must be formed very 

 rapidly on the surface of the hernia-like extrusions of 

 protoplasm. 



I did not observe in Lithamceba any filamentous or 

 elongated pseudopodia, such as are known to accompany 

 hernia-like pseudopodia in Pelomyxa. 



Contractions of the vacuole. — I3uring the movements of 

 the specimen (fig. 1, fig. 2) the large central vacuole was 

 seen to burst and discharge a portion of its contents to the 

 exterior but it did not entirely collapse. Its walls fell 

 together in such a way as to produce two smaller vacuoles, 



