39 
Staurastrum Arctiscon (Lundell) 
„ Aversum „ 
„ Cerastes „ 
„ Cristatum (Nagele) Farsets 
„ longispinum (Bailey) 
„ saxonicum (Reinsch) 
„ paradoxum 
variety longipes (Nordstedt) 
„ pruigstemin (Reinsch) 
Closterium cynthia (de Notaris) 
„ gracile (Bretisson) 
Penium nageli „ 
Those new to the British Isles are : 
Cosmarium Holmiense variety (Lundell) 
„ laeve (Nordstedt and Wittrocli) 
„ nitidulum (de Fotaris) 
„ pseudo nitidulum (Nordstedt) 
„ praemorsum (Bretisson) 
Staurastrum Brasiliense (Lundell) 
„ grande „ 
„ inflexum (Bretisson) 
„ megacan thum (Lundell) 
„ pseudo porciferum (Reinsch) 
„ sebalde (Reinsch) 
Docidium nodosum (Bailey) 
And those new to science are : 
Cosmarium cambricum 
Staurastrum anatinum 
Cosmarium coronatum 
On referring to a paper his father had written on this sub- 
ject he found that no less than 150 distinct species of Des- 
midiae were found at Capel Curig that summer. 
The Staurastra and Cosmaria are both extremely diffi- 
cult to identify, and the species ill defined, and it is often 
almost impossible to name them unless you get several 
aspects of the same object. 
