CAMPYLODISCUS. 379 



C. bicOStatUS W. Sm. (S.B.D., ii., p. 88; Deby, pi. 7, f. 38a; 

 H.V.H. Atl, pi. 75, f. 2*), plate 14, fig. 599. 



Valve appearing almost round, with narrow costa?, the intervals of which 

 are punctate ; median area subquadrangular with rounded angles, showing a 

 second row of costa? separated from the first by a smooth space. Diameter 

 3"5 to 5 '5 c - d - m - 



Marine. Blankenberghe, Antwerp (Scheldt. H.Y. H.), England (Roper, Kitton, Norman, etc.), 

 Ireland (O'Meara), France (Brb.). 



In spite of the opinion of our late friend Mr. Deby, we think that the figure 

 in our Atlas represents faithfully the C. bicostatus of W. Sm. when viewed with 

 an objective of superior quality. The figure was drawn from examples from 

 our Type No. 436 (coming from Africa). Our gatherings from the Scheldt 

 are intermediate in form between Professor Smith's figure and our own. 



Section V. Punctata. Median area punctate or punctato-striate. 



f Valves without ( Rays from 40 to 60 in number . . C. Hibernicus 



intercostal < 



apiculi. ( Rays from 90 to 100 in number . . C. Noricus. 



f Median area angular at its two apices and strongly 

 ,, , . punctate; rays very numerous, commencing with 



vaives witti . a bead _ C. eximius 



intercostal 



a P lc ' Median area elliptic, with rounded apices, provided 



with fine puncta near the costre ; rays contiguous C. limbatus. 



C. Hibernicus Ehr. (Mik., pi. 15A, f. 9; C. cosiatus W. Sm. ; 

 H.V.H. Atl., pi. 77, f- 3*; Type No. 440), plate 14, fig. 593. 



Valve appearing irregularly circular, furnished with costa? (1*5 to 2 in 

 1 c.d.m.), very robust at the margin but becoming gradually thinner near the 

 central portion of the valve, where they leave a subquadrangular punctate 

 space ; stria? fine, intercostal, accompanied by coarse dots, scattered through- 

 out the length of the costs. Frustule very curved ; connecting zone rather 

 broad, bordered with coarse areola?, produced by the commencement of the 

 costa?. Diameter, about 10 c.d.m. 



Freshwater. Rather rare and not abundant ; Louvain (P. Gaut. ) ; Antwerp; England 

 (W. Sm.) ; Ireland (O'Meara). 



var. Noricus. (C. Noricus Ehr. ; H.V.H. Atl., pi. 77, f. 4-6* ; Type 

 No. 441), plate 14, fig. 594. 



Costa? more approximate (2 to 3 in 1 c.d.m.) than the type-form. 



Fresh water. Rare. Rouge-Cloltre (Delogne). England (W. Sm.). 



C. eximius Greg. (Diat. of Clyde, p. 31, pi. 3, f. 54; Deby., pi. 

 10, f. 61*), plate 32, fig. 872. 



