336 GUERNSE Y. 
Navicula nebulosa, Greg. 
A few specimens from extreme low water at Cobo. 
Navicula sp. 
In the same gathering as the last species I found two valves of a 
very beautiful, broadly elliptic form allied to it, but having a narrow 
‘crescent of striae interposed between the median line and the uni- 
formly narrow marginal band, so that there are two granular blank 
spaces and three bands of striae between the median line and the 
edge of the valve. 
Navicula elliptica, Kutz. (WV. ovadis, Sm.) 
Common, often abundant, in fresh-water gatherings. 
Navicula lineata, Donk. 
Three or four specimens from extreme low tide, Cobo. 
Navicula Liber, Sm. 
On Corallines at Moulin Huet and Cobo, frequent. Also fre- 
‘quent at Petit Bot Bay, but mostly a small form. 
Navicula rhombica, Greg. 
Navicula elegans, Sm. 
Abundant in the peaty deposit under the sand at Cobo. 
Navicula palpebralis, Breb. 
Very sparingly in gatherings from Cobo and the Salerie. 
Navicula praetexta, Ehr. 
Three specimens in rock scrapings from low-water mark at 
Perelle Bay ; two from Cobo. 
Navicula pygmaea, Kutz. 
Streamlet near Lilyvale, Catel, scarce. 
Navicula aestiva, Donk. 
More or less frequent in all shore gatherings. Easily recognised 
iby the dry valve being bright blue. 
Navicula Allmaniana, Ralfs. (Piunularia, Greg.) 
Navicula pectinalis, Breb. 
Navicula mesotyla, Ehr. 
Navicula laevissima, Kutz. 
Navicula gibberula, Sm. 
Saints Bay Valley, scarce. 
