532 



COSCINODISCUS. 



C. decipiens Grun. (H.v.H. Atl., pi. 91, f. 10*; Type No. 471, 



C minor of English authors (non Ehr.), plate 34, fig. 905. 



Valve small, with polygonal puncta decreasing regularly from the centre to 

 the circumference, and arranged in eccentric rows. Margin of valve furnished 

 with robust apiculi placed at unequal intervals. Diameter, 2-5 to 3 c.d.m. 



Marine. Lamlash (Greg. ). Woolwich (W. Arnott !). England (Norman, Kitton). Ireland 

 (O'Meara). 



C. Kutzingii Ad. Schm. (Ad. Schm. Atl., pi. 57, f. 17-18*), 

 plate 34, fig. 903. 



Puncta polygonal, about 6 in 1 c.d.m., arranged in eccentric fasciculate 

 rows. Margin without apiculi. Diameter, about 6*5 c.d.m. 



Marine. Firth of Tay. Cuxhaven. 



C. lineatus Ehr. (Kutz.), (Bac, p. 131, pi. 1, f. 10; H.v.H. 



Atl., pi. 131, f- 3> 5 ^d 6*), plate 23, fig. 665. 



Valve circular, with margins furnished with small spines, and sometimes a 

 small process {var. leptopus Grim.) ; alveoles arranged in series forming 

 straight lines in all directions, and in the rather extensive marginal zone much 

 smaller than in the middle of the valve. About 7 to 7*5 series of alveoles 

 in 1 c.d.m. Diameter, about 3 to 10 c.d.m. 



Marine. Blankenberghe, 2nd basin (H.V.H.). Devonshire, England (Baxter Coll., No. 2841). 

 Ireland (O'Meara). 



Group III. Punctati. Valves with puncta only. 



C. nitidus Greg. (Diat. of Clyde, p. 27, pi. 10, f. 25; H.V.H. Atl. 

 Supp., f. 41*), plate 23, fig. 667. 



Valve circular, with very large and very distant puncta, forming more or 

 less radiant lines. Puncta on margin small, arranged in two concentric rows, 

 about 6 to 7 in 1 c.d.m. Diameter, 4 to 5 c.d.m. in the specimens observed. 



Marine. Rare. Blankenberghe, 2nd Basin (H.V.H.), England (Kitton). Cumbrae, Scotland 

 (W. Arnott). Lamlash (Gre v., Greg.). Ireland (O'Meara). Hvidingsoe (A. Schm. ). 



C. Subtilis (Ehr. ?) Grun. (Kaspisch. Meer, p. 27; Diat. Franz. 

 J. Land, p. 29, pi, C ? f, 26*), plate 34, fig. 901. 



