188 MOLLUSCA FROM THE CRAG. 



prominent, and the exterior is covered with ridges parallel to the margin, and varying 

 in number from 16 to 25; these are rounded and obtuse, and rather wider than the 

 spaces between them, and in many of my specimens there are the remains of coloured 

 bands. In the adult shell the margin is covered with about 25 — 30 large crenu- 

 lations. 



Amongst some specimens given to me by Sir Charles Lyell from Touraine, is a 

 single valve of a shell that may probably be referred to this species, but it is not in a 

 sufficiently perfect condition for a fair identification. Amongst a large number of 

 specimens of our Cor. Crag shell, some may be found with the crenulated margin 

 whose diameter does not much exceed half that of others in which such part of the 

 shell is smooth, but the size is no argument against its having attained to a state of 

 maturity. 



Astarte Bosquetii, Nyst, ' Coq. Foss. de Belg.,' pi. vi, fig. 16, which that author has 

 doubtingly referred to A. pygmcBa of Goldfuss, is probably different, and may be the 

 same as A. circinnaria, Mich., it is larger and more angular than our species. Some 

 specimens of A. miniita, Nyst, brought home by Sir Charles Lyell, are also different, 

 and, I think, cannot be referred to our species ; the shell is smaller, more triangular ; 

 the exterior is ridged, and it has a smooth margin : neither can it, in my opinion, be 

 referred to our British species, A. triangularis, nor to A. parvula. 



16, Astarte Burtinii, Lajonkaire. Tab. XVII, fig. 5 a — d. 



Astarte Burtinea. Lajonk. Mem, de la Soc. d'Hist. Nat. de Par,, t. i, p. 129, pi. (>a — c, 

 1823. 



— — Nyst. Rech. Coq. Foss. Prov. d'Anv., p. 8, No. 38, 1835. 



— Burtinii. Id. Coq. Foss. de Belg., p, 160, pi. Ls, fig. 7 a, b, 1844. 



— obliquata. Id. (not Sowerby.) Id., p. 160, pi. vii, fig. 7. 



— pisiroRMis, var. /3. S. Wood. Catalogue. 



Spec Char. Testa crassd, snhtrigomdd, cordiformi, tmnidd, aut compressd, siihincequi- 

 laterali, striatd vel sulcata, striis ohliquis admarginem excurrentibus ; umbonibiisprominulis; 

 lunuld magnd, lavigatd ; margine crenulato. 



Shell thick, sub trigonal, heartshaped, tumid or compressed, slightly inequilateral, 

 striated or sulcated ; striae oblique, running out at the margin ; umbones a little 

 prominent; lunule large, deep, and smooth; margin crenulated. 



Length, ^ths of an inch ; height, fths, nearly 



Length of var. pisiformis, |^ths ditto ; height, yV^^s ditto. 



Localities. Cor. Crag, Sutton, Ramsholt, Sudbourn, and Gedgrave. 

 Red Crag, Sutton. 



Very abundant in the Cor. Crag, but exceedingly scarce in the Red, so much so, 

 that judging from my own collection, it is doubtful if true and genuine specimens have 

 been found in it. 



