STAUKASTKUM. 99 



Semicells, excluding the processes, relatively a little 

 longer than in the type, slender and campanulate, 

 gracefully inflated at the base ; sinus deeper than usual, 

 and almost linear ; processes long and slender, bifid at 

 the apex ; in vertical view triangular, with a series of 

 small granules within the lateral margins. 



Length 52 [i ; breadth, including processes, 95 ji ; 

 breadth at base of semicell 18[i ; breadth of isthmus 



11 [L. 



IRELAND.- -Lough Darragh, Donegal ! Derryclare 

 Lough, Gal way ! 



The chief distinction between var. bulbosum and the typical 

 form seems to be the gracefully swollen base of the semi- 

 cell. Intermediate stages, however, do occur. For example 

 the peculiar specimen figured on PL CXLIV, fig. 6 from the 

 plankton of Loch Doon shows a tendency to cylindrical form 

 of the body of the semicell with slightly inflated base. 



Var. cyathiforme W. & G. S. West. (PL CXLIV, 



fig. 12.) 



St. gracile var. cyathiforme West & G. S. West, Freshw. Alg. Madag. 1895, 

 p. 77, t. 9, f. 2 ; Wehv. Afric. Alg. 1897, p. 182 ; Furth. Contrib. Plankton 

 .Scott, Lochs, 1905, p. 504. 



Semicells cyathiform, slightly swollen at the base, 

 lateral margins undulate and denticulate, apex of semi- 

 cell convex, with a row of emarginate verrucse continued 

 as smaller teeth along the dorsal margin of the processes, 

 which are tipped with a few small spines ; vertical view 

 with a series of emaminate verrucse within each lateral 



o 



margin ; cell- wall punctate. 



Length 52-58 p ; breadth, including processes, 80- 

 88 pi ; breadth of isthmus 8-15 p. 



SCOTLAND. Plankton of Lochs an Sgath and Fada- 

 ghoda, Lewis, Outer Hebrides ! 



IRELAND. Plankton of Loch Currane, Kerry ! 



Geogr. Distribution. Central China (form). Mada- 

 gascar. W. Africa. 



The British examples of this variety differ from the originaUy 



