TYNDARIDEA. 163 



circular, contained within the cells. Cells usually rather 

 more than twice as long as broad. 



Tyndaridea bicornis, Annals of Nat. Hist. vol. x. p. 43. 

 Hob. Cheshunt and other places : A. H. H. 



This species is by no means uncommon, and is certainly 

 distinct. A species described in the 10th vol. of the Annals 

 of Nat. Hist, under the name of T. interposita, ought, I think, 

 to be regarded as a variety of the species. Fig. 8. plate 

 xxxviu. may perhaps represent a species distinct from T. 

 bicornis. I have more than once met with it just as repre- 

 sented in the figure. 



5. T. INSIGNIS Hass. 

 Plate XXXVIII. Figs. 6, 7. 



Char. Filaments rather smaller than those of T. bicornis. 

 Cells twice as long as broad, and frequently curiously 

 distorted, that side of them which either has or is about 

 to unite itself with another, becoming remarkably protube- 

 rant. Sporangia circular, and partly lodged in the trans- 

 verse tubes. 



Hob. High Beech, Wanstead, and other places : A. H. H. 

 Rusthall Common ; in a pool by the road- side between 

 Cross in Hand and Heathfield ; pond near Five Ashes, 

 Mayfield ; on Waterdown Forest ; Greatham and 

 Storrington Commons : Mr. Jenner. 



This species, which sometimes presents an appearance so 

 remarkable, was first sent me by Mr. Jenner. It is by no 

 means uncommon, and I think certainly distinct from all 

 others with which I am acquainted. 



6. TYNDARIDEA STAGNALIS Hass. 

 Plate XXXVIII. Fig. 9. 



Char. Filaments more slender than those of T. insignis. Cells 

 about two and a half times as long as broad. Sporangia 

 M 2 



