Lankester— Craq. 151 
Isocardia cor, Lin., is a very rare shell in our Suffolk Crag; in the 
Middle Crag of Antwerp it is abundant. Nodules of fine sandstone 
are abundant in our own Red Crag, containing generally Pectunculus 
glycimeris, an abundant shell also at Antwerp, or frequently Iso- 
cardia cor, and sometimes a Cetacean tooth. The conclusion is 
irresistible, that these nodules are portions of lost Middle Crag 
beds, the equivalents of the Middle Pliocene of Antwerp. 
The following may be taken as a synopsis of the formations above 
treated of :— 
Upper Pliocene. 
Red Crag; Coralline Crag ; Upper Antwerp Crag. 
Middle Pliocene. 
Middle Crag of Antwerp. 
Lower Pliocene. 
Lower or Black Crag of Antwerp; Miocéne supérieur of 
Bordeaux and Vienna. 
I subjoin a list of some of the derivative fossils in the Red and 
Coralline Crags:— 
1. Ammonites, Pecten, &c., from the Upper Greensand. 
2. Flint Sponges, Echinoderms, &c., from the Chalk. 
3. Lower Kocene Mollusca in nodules, from the Thanet Sand, &c. 
4. ‘Coprolitic’ nodules, and very numerous Crustacea, Teeth, and other 
Fish remains from the London Clay. 
5. Teeth of Carcharodon heteredon, and jaws of Edaphodon, from Middle 
Eocene Beds. 
6. Mastodon Arvernense, Rhinoceros, Tapirus, Sus, &c., from Miocene or 
Pliocene Beds. 
7. Carcharodon megalodon, Rhinchoceti, Squalodon, Trichecodon, &c., from 
Middle Pliocene Beds. 
8. Cn Red Crag) Pectunculus glycimeris and very many other Shells from 
the Coralline Crag. 
(See also Mr. S. Wood’s List of the Derived Fossils, Quart. Journ. Geol. 
Soc., vol. xv., p. 33, &c.) 
TABLE SHOWING THE RELATIONSHIPS OF THE SEVERAL CRAGS OF SUFFOLK AND 
ANTWERP; AS DERIVED FROM LISTS OF THEIR MOLLUSCA. 
RC.—Red Crag. CC.—Coralline Crag. UAC.—Upper Antwerp Crag. MAC.—Middle Antwerp 
Crag. LAC.—Lower Antwerp Crag. 
| Ex- 
RO.| CC. UAC |aac Lac | 28 | Hy- 
> Extinct 
species. } DARN SRA AN MA 26 species common to all 
Living ) five. 
species. f OPED WEE ERO NAN eat 
cnr PACHEG) | Og Oe renin |e cc cumen a wd ee 
Living. 12 | 12] 12) 12) — | — | 12 | [ cont from LAC. 
; 17 common to RC., CC., 
Extinct. OE MOC BOR Saal iOS ecu eee UAC., but absent from 
Living. SlerS oS ksh aa (384 | aaa se LAC. 
; 56 common to RC. & 
pextimet. | 205) 20 | Se | | 29. Se UGC. hut absent tonal! 
Living. LOA ELON ee IN rare | ecaer irra CLS lal FTA Gl AMIN 
