

z 





PODOCYSTIS. 







365 



GENUS 75. PODOCYSTIS KUTZ, 1844. 



Valves cuneate, furnished with transverse costae 

 and distinct pseudo-raphe. Frustules cuneate, stipi- 

 tate, without obvious alae. 



Fig. 117. 



Po iocystis 

 Adriatica, 



Podocystis Adriatica Kutz. (Baa, p. 62; h.v.h. Atl., pi. 



55, f. 8*; Type No. 366), fig. 117 above. 



Valve cuneate, sometimes attenuate near the base, furnished with trans- 

 verse costae and rather fine puncta, arranged in transverse and oblique rows. 



Marine. Southern shores of England (W. Sm. , Roper), Ireland (O'Meara). 



This diatom belongs especially to the Mediterranean and Adriatic. 



Euphyllodium spathulatum Shadb. is also a Podocystis, 

 but it cannot be considered as identical with P. Adriatica, as De Toni and 

 other authors make it. The valves are furnished with a net work of transverse 

 and longitudinal costae, anastomosed, thickened ; at the bottom of the cavities 

 formed by this network is found a transverse costa, excessively delicate, and 

 bearing on each margin a very minute beard. I therefore assign to this form 

 the name of 



Podocystis spathulatum (Shadb.) H.V.H. The valve 



is similar in form to the preceding species. It inhabits the Islands of Ceylon, 

 Nankoori, etc. It is, perhaps, identical with P. Australica Witt, which I 

 only know from the description given by De Toni. In the latter case the name 

 of Shadbolt should be retained, as the species of Witt dates from 1873, while 

 that of Shadbolt was described in 1854. 



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