ACHNANTHES. 401 



which circumstance, together with the colour and slender fila- 

 ments, will distinguish it from all other species." — Ralfs. 



67. ACHNANTHES Bory, 



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

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

 punctum at the centre of the inferior margin. 



Derivation. From a')(y7], 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 stricB. Stipes very short. 



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

 pi. XX. f. 5. ; Ralfs, in Annals, vol. xiii. p. 492. pi. xiv. 

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



Hah. Parasitic on other AlgcB, New timber, Sussex : Mr. 

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

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

 zance : Mr. Ralfs. Bristol : 3Ir. 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 Klitzing'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 

 Klitzing's Achnanthes minutissima.^^ — Ralfs. 



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