Algonkian Algce in Permian of England. 199 



Structure of the Neivlandia type. — Walcott's diagnosis 

 of Newlandia is (p. 104) : '^More or less irregular semi- 

 spherical or froiidlike forms built up of concentric, 

 subparallel, subequidistant thin layers that may be con- 

 nected by very irregular, broken partitions." By com- 

 paring my figure 1 with Walcott's plate 6, especially 

 figure 2 (of iV. frondosa), the strikingly similar features 

 will be seen. This likeness is still greater between my 

 figure 2 and Walcott's plate 7, figures 1 and 2, where the 



Fig. 5. — Same specimen as in fig. 4. Vertical section tlirough tubes. 



concentric laminge are less strongly and less regularly 

 curved. My figure 3 shows a structure similar to his 

 figure 1 of the same plate, yet with somewhat thinner and 

 regularly spherical laminae. A small ball-like specimen 

 in my collection, 6 cm. in diameter, shows a concentric 

 structure with the same very slight thickness of the 

 laminge as in Walcott's illustrations of A"". lameUosa, 

 plate 10, figures 1 and 2. There is no doubt that the same 

 structure can easily be found in larger masses, giving a 

 picture like those of Walcott. 



Structure of the Greysonia type. — Walcott's diagnosis 

 of Greysonia (p. 108) reads as follows: "Irregular, 

 cylindrical or tubular growth with relatively thin walls 

 except at the union of three or more tubes, where the 

 walls are thickened . . . The tubes are large, irregularly 

 rhomboidal or pentagonal in section with the interior now 

 filled in with a dark bluish-grey limestone. The walls 



