1853.] SHARPE SANDS AND GRAVELS OF FARRINGDON. 197 



crust is cellular, but as few of these cells have openings, it is probable 

 that the pores in its surface were gradually filled up ; the ridges are 

 formed of oblique tubular cells with small rounded openings, arranged 

 in oblique lines, forming three or four rows on each side of the ridges ; 

 and these rows are continued beyond the ridges in the flat crust. 



Common at Little Coxwell near Farringdon, and also found in the 

 Upper green sand of Chute Farm near Warminster. 



Plate V. fig. 7 «. A well-preserved specimen covering a branch of 

 Verticillipora anastomosans. 



Fig. 7 b. Portion of 7 a magnified. 



Fig. 7 c. A worn specimen on a pebble ; the cells are laid open by 

 the wearing of the tops of the ridge. 



Fig. 7 6?. A portion magnified. 



This pretty Coralline probably belongs to Dr. Hagenow's genus 

 Lopholepis, but it is larger and has the pores more regularly disposed 

 than either of his species. It has much resemblance also to Repto- 

 clausa Neocomiensis and jR. obliqua of M. d'Orbigny. It is named 

 after Dr. Hagenow, author of the * Bryozoen der Maastrichter 

 Kreidebildung.' 



Plicatula iNiEQuiDENs, Sliarpe. Pl. VI, fig. 3. 



P. testa oblonga; valva inferiore omnino affixa; cardinis dentibus valde 

 insequalibus, transverse rugosis. 



Shell oblong, attached by the whole surface of the lower valve, and 

 adapting itself to the form of the body on which it grows ; hinge- 

 teeth very unequal and transversely furrowed. 



Length ] inch, breadth y gths of an inch. 



In the gravel of Little Coxwell, attached to Ostrcea macro'ptera. 



The form of this shell and of its hinge is so peculiar that I have 

 figured it, although I have only seen one valve. 



Plate VI. fig. 3 a. Interior of lower valve. 



Fig. 3 h. Hinge-teeth of the same, enlarged. 



DiANCHORA? GUTTATA, Sharpc. Pl. VI. fig. 4. 



P. testa oblonga; valva inferiore affixa; superiore tenuissima, longitu- 

 dinaliter striata; striis insequalibus, guttatim nodosis. 



Shell oblong, flat, very irregular ; fixed by nearly the whole sur- 

 face of the lower valve, and taking the form of the bodies upon which 

 it grows ; upper valve very thin, ornamented with numerous, close 

 set, radiating ribs, very unevenly covered with guttate, spinous pro- 

 jections. 



Length 1 inch, breadth -j^ths of an inch. 



Common in the gravel of Little Coxwell, adhering to Oysters, 

 Sponges, &c. 



Although this species is abundant in the Farringdon gravel, it is 

 generally so much broken that it has been necessary to frame the 

 above description from a number of fragments, none of which show 

 the hinge distinctly : the shell was apparently very thin at the hinge. 

 Not being satisfied with the reasons which have led many authors to 



