334 Mr. J. Ralfs on the Nostochinee. 
The turgid sporangia and large, compressed vesicular cells 
characterise the species. 
Puare VIII. fig. 11. a, immature state; 6, mature state. 
6. S. Mooreana ( ). Ordinary joints subspherical ; vesicular cells 
barrel-shaped, much narrower than the large broadly-elliptic spo- 
rangia. 
Ireland, Mr. Moore, to whom I am indebted for specimens. 
Ordinary cells minute, somewhat orbicular. Sporangia very 
turgid, often nearly orbicular, much larger than either the vesi- 
cular or the ordinary cells. Vesicular cells minute, smooth and 
barrel-shaped. 
I regret that I have only seen imperfect and dried filaments of 
this species intermixed with Nostoc variegatum, Moore ; im a re- 
cent state therefore the form of the ordinary cells may not agree 
with the above description, still the large turgid sporangia must 
distinguish it from every species but Spherozyga Berkeleyana, 
and from that it differs in its vesicular cells, which are compara- 
tively much smaller and also longer than broad. 
Piate VIII. fig. 12. Mature filament. 
*** Dissepiments obscure, cells longer than broad. 
7. S. leptosperma (Kiitzing). Filaments elongated, not constricted 
at the dissepiments ; ordinary joints longer than broad, confluent ; 
vesicular cells elliptic ; sporangia linear. Cylindrospermum lepto- 
spermum, Kiitzing, Bot. Zeit. 1847, p. 198; Species Algarum, 
p- 294; Tabulze Phycologicze, t. 99. fig. 11. 
Ditches and pools. Near Carnarvon and near Barmouth, J. R. 
France, Lenormand. 
Spherozyga leptosperma occurs in large, shapeless, gelatinous 
masses in still waters. Its colour varies from deep green to pale 
yellowish green, but when the filaments are comparatively few it is 
nearly colourless. The ordinary joints are longer than broad, sepa- 
rated only by transverse dissepiments, which are not contracted, 
and indeed are often so obscure, that, in the recent state, they 
can hardly be detected, whilst the filaments, in all respects but 
their enlarged cells, appear not unlike those of an Oscz/latoria. 
Vesicular cells at first barrel-shaped, finally elliptic, and as broad 
as the sporangia, the early state of which they somewhat resemble, 
but they may be recognized by the absence of granular contents 
and by their globules. Sporangia cylindrical, four to six times 
longer than broad, truncate, slightly broader than the ordinary 
cells. 
The confluent ordinary cells with their obscure dissepiments 
distinguish Spherozyga leptosperma from every other British 
species. 
Puate VIII. fig. 13. Mature filament. 
