MARINE DIATOMACEA OF THE L.M.B.C. DISTRICT. 3 
found in this neighbourhood the siliceous skeleton is but 
poorly developed. 
No department of Botany has been more fully illustrated 
than the Diatoms. A very good Bibliography is found in 
Dr. Van Heurck’s “ Synopsis,”’ ch. i., p. 48, and it is 
hardly necessary in the list that follows to give more than 
the authority upon which the names of genera and species 
rest. I have not considered it necessary to give the 
authorities in full, as the abbreviations are well known to 
those who study the subject. 
The localities mentioned in the list are those in which 
the form was first observed. 
Very rare means that only a very few forms have 
been seen. 
Rare, that the form has only been seen in a very few 
gatherings, but may have been abundant in them. 
Common, that the form has appeared in many 
gatherings. 
Very common, that the form is present in most of the 
gatherings and is abundant. 
LIstT. 
Achnanthes (Bory, 1822) brevipes, Ag. Surface of Dee, 
common. 
A. longipes, Ag. Hoylake, common. 
A. subsessilis, Khr. Ince Marsh, rare. 
Actinocyclus (Ehr.) crassus, W.Sm. Surface of Dee, rare. 
A. ralfsu, W. Sm. Parkgate, rare. 
Actinoptychus (Ehr.) splendens (Shad), Ralfs. Surface of 
Dee, rare. 
A. undulatus, Ehr. Queen’s Ferry, very common. 
Amphiprora (Kutz.) alata, Kutz. Mostyn, very common. 
A. paludosa, Greg. Mostyn, common. 
