Dr. H. A. Nicholson on the Genus Climacograpsus. 371 
e stipe, and transversely oval or subquadrate; cell- 
denticles or appendages, if present, usually on the upper 
pot 
peo at the end of tooth-like “‘ denticles," as in Diplograpsus. 
n lateral views of C limaeograpsus, where the frond is simply 
appea num of 
sunk below the general level of the polypary. 
Specimens such as these that Professor Goy founded his 
Diplograpsus rectangularis (Pal. Foss. p. 8, pl. 18. fig. 8). 
Judging, also, merely from examples of this nature, it would 
certainly be supposed that the cellules of Climacograpsus were 
not separated one from another by distinct cell-partitions. It 
Was pointed out, however, by Salter that it was often possible 
to trace from the base of each cell-mouth a short impressed 
line, extending nearly as far as the next cell-mouth below 
(Quart. Journ. Geol. Soc. vol. viii. p. 389, pl. 21. figs. 3 b, 4b). 
That this line is truly the edge of a cell-partition is shown 
conclusively by an examination of — age in 
relief (fig. 1 ¢ , of which the Coniston udstones have yielded 
to me a magnificent series. From these specimens it becomes 
at once evident that the cellules in Climacograpsus are really 
as distinct from one another as in Diplograpsus, each cellule 
being bent so that its outer portion becomes parallel with the 
axis of the frond, thus bringing the cell-mouth directly beneath 
the cellule immediately above. The piii of this 
