164 CONJUGATED. 



circular, extending into a portion of the connecting tubes. 

 T. stagnalis. 



Hassall, in Annals of Nat. Hist. vol. x. p. 42. 



Hab. Abundant on Hertford Heath and other places in 



the counties of Hertfordshire and Essex: A. II. H. 



Rusthall Common ; Waterdown Forest, and near Cross 



in Hand. 



This is a distinct and common species. Fig. 10. plate 

 xxxviii. may possibly be distinct from this. 



Second subgenus. Sporangia lodged in the transverse tubes. 



7. TYNDARIDEA IMMERSA Hass. 



Plate XXXIX. Fig. 3. 



Char. Filaments of considerable diameter. Cells about once 

 and a half or twice as long as broad. Endochrome dis- 

 tinctly stellate. Sporangia large, circular, and partly im- 

 mersed in the cells. 

 Tyndaridea conspicua, Annals of Nat. Hist. vol. xii. 



p. 187. pi. 7. fig. 17. 

 Hob. Wimbledon Common : A. IL H. 



" This species bears considerable resemblance to Vauchcr's 

 figure of T. pectinata. I do not think, however, that it is 

 that species, for I presume that Vaucher employed the same 

 magnifying power to all his figures ; in which case the fila- 

 ments of T. pectinata would be almost equal in diameter 

 to those of Z. quininum, and consequently nearly as large again 

 as those of the present species." Annals. 



8. TYNDARIDEA CONSPICUA Hass. 

 Plate XXXIX. Figs. 1, 2. 



Char. Filaments rather smaller than those of the preceding 

 species. Cells usually twice, or twice and a half as long as 



