342 



LICMOPHORA. 



Licmophora are found in all regions of the globe, the North Sea producing 

 a large number, as the following table demonstrates. 



ANALYSIS OF SPECIES. 



/. Frustules scarcely septate. 



' Valve very long and narrow, of almost equal breadth at the two apices . L. flabellata. 

 Valve very gently attenuated from the summit to the base . L. Juergensii. 

 ( Valve abruptly attenuated towards the lower \ L. Dalmatica. 



Valve with 

 superior 

 apex con- 

 siderably 

 broader 

 than the 

 inferior. 



Valve Valve f Valve large, broad, 24 strias in 



abruptly J abruptly 1 c.d.m. . . L. gracilis. 



attenuated { attenuated 



near the 

 base. 



towards 



1 



the inferior | Valve small, narrow, 25 striae 



^rd. ^ in 1 c.d.m. . . L. Anglica. 



II. Frustules profoundly septate. 



C Valves very broadly cuneate, strias very robust . . L. 



Valves rather broad, about 27 striae in 1 c.d.m. 



Valves not 



broadly 



cuneate ; 



strias fine 



or very 



fine. 



Valves 



abruptly 



attenuated 



near the 



base. 



Valves 



infinitesi- 



mally 

 attenuate. 



at the middle of the valve 



Ehrenbergii. 

 paradoxa. 



Valves 

 very 



Girdle 



face 

 broadly 

 cuneate. 



f Striae rather fine, about 13 in 1 

 c.d.m. in the middle of the 

 valve . . . L. Lyngbyei. 



"1 



I Strias very fine, about 30 in 1 

 c.d.m. in the middle of the 

 ^ valve . . . L. tincta. 



Septa very arcuate, about 23 

 strias in 1 c.d m. in the mid- 

 dle of the valve . L. communis. 



i Septa slightly arcuate, about 30 

 strias in 1 c.d.m. in the mid- 

 L die of the valve . . L. nubecula. 



i Girdle face very narrowly cuneate, about 16 



^ strire in 1 c.d.m. in the middle of the valve . L. tenuis. 



/. Frustules scarcely septate. 

 a. Apices almost of the same breadth. 



L. flabellata (Carm.) Ag. (Consp., p. 41 ; h.v.h. Atl., pi. 46, 



f. 2-3* ; Type No. 323), plate 31, fig. 852. 



Valves excessively long and narrow, cuneate, lanceolate, attenuate towards 

 the inferior apex, which is inflated, subcapitate. Striae about 30 in 1 c.d.m. 

 Girdle face cuneate, very narrow. Length, up to 30 c.d.m. 



Marine. North Sea. England (W. Sm., Ralfs, Mrs. Griffiths). Scotland (Dickie, 

 Carmichael), Ireland (O'Meara). 



