CAMPYLODISCUS. 377 



Section II. Vagce. Area vaguely limited in consequence of 

 the absence of the rays. 



i Valves with very small puncta, forming short lines, interrupted by a hyaline 



circle . . . . . E. Echeneis. 



(Valves with very coarse puncta, forming continued radial lines . . E. Clypeus. 



C. Echeneis Ehr. {Coronia Echeneis Ehr.,V>tx., 1841 ; C.cribrosus 

 W. Sm., Deby, pi. 9, f. 50 ; H.V.H. Atl., pi. 76, f. 1 and 2* ; Type No. 437), 

 plate 14, fig. 600. 



Valve appearing irregularly circular, with cost?e scarcely noticeable at 

 margin, replaced over the remainder of their length by rows of elongated 

 coarse beads, very variable in number. Pseudo-raphj in the form of a blank 

 space of greater or less breadth. Diameter, 8 to 14 c.d.m. 



Fresh and brackish water. Washings of mussels (Deby), Antwerp (Scheldt), Blankenberghe 

 (H.V.H). Very rare. France. Bahnsie. England (Brightwell, W. Sm., Comber, Stolt., Norm.), 

 Ireland (O'Meara). 



C. Clypeus Ehr. (Mikr. pi. 10, f. I. i ; Deby pi. 9, f. 49 ; H.V.H. 

 Atl., pi. 75, f. 1*, Type 435), plate 14. fig. 598. 



Valve very large, regularly circular, with costre (1-5 in 1 c.d.m.) occupying 

 only about the moiety of the ray, interrupted on the two sides by a very 

 broad sulcus (inflexion of the valve). Central portion of the valve occupied 

 by coarse puncta arranged irregularly, inteirupted by a rather broad pseudo 

 raphe and circumscribed by a second broad depression of the valve. Inter- 

 costal stria?, 21 in 1 c.d.m., formed of elongated puncta, and accompanied by 

 coarse puncta arranged throughout the entire length of the costae. Diameter, 

 about 20 c.d.m. 



Brackish water. Ostend (Grunow), Heyst (Deby), Antwerp (Scheldt), Blankenberghe (H.V.H.), 

 England (Wighani, Okeden), frequent. Cuxhaven, Bremershaven. 



Section III. Hyalines. Valve with a large, smooth, hyaline 

 central area, without any puncta. 



C Hyaline area limited by a circlet of puncta, narrow portion 

 Rays in- (stem) of rays often longer than the broader portion 



fundibuli- (funnel) . C. Horologium. 



form . 



I Hyaline area not limited by a circlet of puncta, intercostal 



spaces smooth . . C. latus. 



I Rays not infundibuliform ; hyaline area elliptic, with acute apices ; rays 



not originating in a single very coarse bead . . . C. annularis. 



C. Horologium Williams (in Ann. and Mag. of Nat. Hist., 

 1848, Deby, plate 6, f. 29a*), plate 32, fig. 870. 



