ACHNANTHES. 401 



which circumstance, together with the colour and slender fila- 

 ments, will distinguish it from all other species." Rolfs. 



67. ACHNANTHES Bory. 



Char. Frond stipitate, standard-shaped, composed of few 

 frustules, which are longer than broad, curved, and have a 

 punctum at the centre of the inferior margin. 



Derivation. From a^vrj, the froth of the ocean, and avOos, 

 a flower. 



The stipes is attached not to the centre of the lower frus- 

 tule but to one of its angles, and this position of it gives rise 

 to the resemblance of each entire frond to a standard. 



1. ACHNANTHES MINUTISSIMA Kutz. 

 Plate C. Fig. 4. 



Char. Frustules small, slender ; in lateral view obtuse, and 

 apparently without strice. Stipes very short. 



Kutz. Syn. Diatom, p. 578. f. 54. ; Ehr. Infus. p. 228. 



pi. xx. f. 5. ; Ealfs, in Annals, vol. xiii. p. 492. pi. xiv. 



fig. 2. ; Jenner, in Flor. of Tunbridge Wells, p. 200. 

 Hab. Parasitic on other Alga, Newtimber, Sussex : Mr. 



Borrer. Several places in Sussex, &c. : Mr. Jenner. 



Cheshunt : A. H. H. Oswestry : Rev. T. Salwey. Pen- 



zance : Mr. Rolfs. Bristol : Mr. Thwaites. 



The fronds are very minute, and rarely consist of more than 

 two frustules. 



" Before I had the opportunity through Mr. Borrer's kind- 

 ness of comparing our plant with the specimen in Kiitzing's 

 ' Alg. Aq. Dulc.' I considered it a variety of the following 

 species; and I am still uncertain whether they should be 

 separated, although the plant above described is undoubtedly 

 Kiitzing's Achnanthes minutissima." Rolfs. 



D D 



