PEPONIA. 



43 1 



The genus also includes Kten. Rossicus Pant., which has been found at 

 Kusnetzk (Russia), which differs from the preceding form by its less developed 

 comb and by the broad hyaline margin of the valve. 



GENUS 98. PEPONIA GREV., 1863. 



Valves inflated, subcircular, 

 with margin abruptly prolonged 

 into a triangular apiculus, obtuse 

 on the two opposite sides. Surface 

 of the valve and of the apiculus 

 areolate. Apiculus with apex raised 

 into a short horn. 



Fig. 153. Peponia Barbadensis. 



This genus only includes one 

 species, P. Barbadensis Grev. (fig. 

 153), which has been found in Barba- 



does deposits, Bridgewater (!) and Cambridge Estate. 



# * u , s * * 



tO0 0# ] 



Fig. 154- 



Strang u lone ma 

 Barbadensis, 



GENUS 99. STRANGULONEMA 

 GREV., 1865. 



Frustules puncto-areolate, united into a cylindrical 

 filament. Valves constricted near the apices, then 

 spread out and enlarged into a nodule. 



This genus was created for S. Barbadensis Grev. We 

 reproduce the figure of this author (fig. 154), but in the 

 specimen of this diatom in my possession the constriction 

 is abrupt and not like the neck of a decanter, as designed 

 by Greville. Nor can I recognise the undulated soldering 

 of the adjacent nodules. This very rare diatom is found 

 in the Cambridge Estate (Barbadoes). 



