podosira. 447 



var. radiosa Grun. (H.V.H. Atl., pi. 92, f. 23, and pi. 93, f. 1-9*; 

 in Type No. 475), plate 22, fig. 654. 



Larger than the type-form, with centre showing punctate striae distinctly 

 radiant. Attaining as much as 4 c.d.m. 



Not yet found in Belgium. Scotland (H.V.H. , Type No. 475). 



C. Operculata KlitZ. (Baa, p. 50, pi. r, f. i, 12 and 15 ; H.V.H. 

 Atl., pi. 93, f. 22-28* ; Type No. 476, var. mesoleia), plate 22, fig. 655. 



Valves with rather marked marginal costs, intermixed with small spines 

 arranged regularly. Centre finely punctate, puncta scattered {var. mesoleia 

 Grun.) or radiant (var. radiosa Grun.). Girdle face undulate, 16 or 17 costas 

 in 1 c.d.m. Diameter, 1*25 to 3 c.d.m. 



Fresh water. Not yet recorded in Belgium, but found in France, England (Kitton, Comber, 

 Norman), Ireland (Dickie, O'Meara). 



C. Meneghiniana Kiitz. (Baa. p. 50, pi. 30, f. 68 ; C. Kutzing- 



iana IV. Sm. f \ H.V.H. Atl., pi. 94, f. 11-13*; in Type No. 478; forma 

 minor: Type No. 479; var. redangulata Bred.: Type No. 480), plate 22, 

 fig. 656. 



Valve with robust marginal striae, delicately punctate, transversely ; centre 

 with fine radiant dots and one or two coarse dots placed almost in the middle 

 of the ray. Girdle face undulated. Striae, 7 to 9 in 1 c.d.m. Diameter, 1 to 

 2 c.d.m. 



Fresh water. Antwerp, Holland, England (Kitton, Norman), Ireland (O'Meara). 



C. Kutzingiana Chauvin. (H.V.H. Atl., pi. 94, f. i, \ and 6* ; 



Type No. 477), plate 22, fig. 657. 



Valve with fine marginal costae, centre very finely punctate, puncta scat- 

 tered, with sometimes i to 3 coarse isolated dots. Girdle face strongly 

 undulated. Striae, 12 to 14 in 1 c.dm. Diameter, 1-25 to 2-5 c.d.m. 



Freshwater. Antwerp, and probably in many other localities in Belgium; Falaise (Fiance, 

 Breb. !) ; England (various localities : Thwaites, Norman, Kitton, Comber, Shadbolt, W. Arnott, 

 etc.) ; Scotland (Baxter Coll., No. 2530) ; Ireland (O'Meara). 



GENUS 112. PODOSIRA EHR, 1840. 



Valves very convex, hemi-spherical, 

 finely punctate or subareolate, puncta 

 extending regularly throughout the 

 valve. Frustules stipitate, solitary, 

 or united by 2 or 3 by means of a 

 gelatinous neck. 



Fig. 171. Podosira Adriatica. Marine. 



