180 Transactions of the Royal Microscopical Society. 
what elongated, thus bearing a strong resemblance to those in 
Amphipleura. The valves of the genuine A. pellucida are narrow, 
lanceolate, '09- '13 mm. long and • 007- • 009 mm. broad. Length 
of “ forks” not exceeding ■ 02 mm. Striae 37-39 in '01 mm. 
Schumann has found in the Baltic two large specimens of 
Amphipleura (‘ Schrift. d’Konigsberg Phys. Ok. Gesell.,’ 1867) 
tab. i., fig. 9), which are '18- -20 mm. long and '14 mm. 
broad. The striation is very coarse (16 in '01 mm.). This is also 
a doubtful variety of A. pellucida, and may be called A. Schumanni. 
Schumann delineates the striae of A. Schumanni and A. pellucida 
(‘ Diat. der Hohen Tatra,’ tab. ii., fig. 10) as composed of three large 
distant dots forming coarse longitudinal striae on each side of the 
valve * But this is an optical delusion, the striae in A. pellucida 
and all its varieties consist of rows of numerous very minute dots. 
A. Weissflogii Janisch differs from A. pellucida and A. Oregonica 
by its exactly linear valves and rounded apices. Length • 19- '25 
mm., breadth of valve • 012- ■ 013 mm. ; length of “ forks ” • 06- ' 08 
mm. Striae 25 in '01 mm. Oregon deposit; rare. PI. CXCV., 
Fig. 14. This figure represents the authentic specimen of Janisch, 
and shows a very abnormal condition of the terminal nodules ; in 
normal specimens they are exactly like those of A. Lindheimeri. 
A. danica, Kg. ? This is a true Amphipleura, if Schumann’s 
figure ( l . c., tab. i., fig. 3) represents the genuine species of Kiitzing, 
which, however, seems to me very doubtful. The valve of A. danica 
Schu., is linear, with rounded apices: the frustules of A. danica 
Kg., are lanceolate, and, as it seems, fusiform, like those of my 
Navicula fusiformis, to which it seems to be nearly related. 
From Amphipleura must he separated A. injlexa Breb., as I 
suggested long ago in Hedwigia. The late Dr. Eulenstein proposed 
naming it Okedenia, and as I am not aware of any other genus 
Okedenia, I adopt Eulenstein’s name. 
BerJceleya. 
The species belonging to the genus Berkeley a are B. Dilhvynnii 
Grun., including a great many species of Schizonema (see Hedwigia 
and Novara Exp.); B. micans (Lyng.), Kg.; Bangia micans 
Lyngbye ; Rhaphidogloia micans Kg. ; BerJceleya fragilis Greville 
(nec Smith, ‘ Brit. Diat.,’ pi. liv., fig. 344 ; his figure resembles 
Navicula scopulorum) ; B. Adriatica Kg. Striae, 24 in '01 mm. 
PI. CXCV., Fig. 15. 
B. manipulata (Kg.) = Raphidogloia Kg. 
B. medusina (Kg.) = „ „ 
Both are very nearly related to B. micans. 
* A copy of Schumann’s figure will be found in the ‘ M. M. J.’ (“ On Dr. 
Schumann’s Formulae for Diatom Lines,” by W. J. Hickie), vol. xiv., PI. CIX., 
Fig. 1. — F. K. 
