1866.] 



WOOD EED CRAG. 



543 



Modiola marmorata, Forbes. 

 Pectunciilus glycimeris, var. 



obliquus. 

 Area lactea, Linn. 

 Nucula Igevigata, J. Sow. 

 Kellia suborbicularis, Mont. 

 Scintilla ambigua, Ni/st. 

 Montacuta bidentata, Mont. 

 Lucina borealis, Linn. 

 Cardium edule, Linn. 



Parkinsoni, J. Sow. 



venustum, S. Wood. 



Cardita (senilis) sulcata? 



■ scalaris, Leathes. 



corbis, Philippi. 



Astarte Basterotii ?, Lajonk. 



incrassata, Broc. 



crebrilirata, S. Wood. 



gracilis?, Milnst., var. 



obliquata, J. Sow. 



triangularis, Mont. 



Astarte digitaria, Linn. 

 Cyprina Islandica ?, fragment. 



rustica, J. Sow. 



Tapes virgineus, Linn. 

 texturatus, Lam. 



Bivalves {continued). 



! Venerupis Irus, Linn. 

 sub- Cytherea rudis, Poli. 



Venus fasciata, Dacosta. 



imbricata, J. Sow. 



'.. Artemis lentiformis, J. Sow. 



lincta, Pulteney. 



Gastrana laminosa, J. Sow. 



Tellina crassa, Penn. 



Abra alba, W. Wood. 



fabalis, ? S. Wood, var. 



Mactra areuata, J. Sow. 



truncata, ? ovalis. 



deaurata, Turt.{^die J. Brown). 



Solen gladiolus, Gray. 



ensis, Linn. 



Cultellus tenuis, Phil. 



Cochlodesma complanatum, 

 S. Wood. 



Pandora pinna, Mont. 



Corbula gibba, Olivi. 



Corbulomya complanata, J. Sow. 



Panopsea Faujasii?, Men. dela Groy. 



Saxicava rugosa, Linn. 

 . Pholas cylindrica, J. Sow. 



crispata, Linn. 



Terebratula grandis, Blumen. 



The next well-marked division of the Eed Crag is that from which 

 I obtained the principal part of the fauna described in the ' Mono- 

 graph of the Crag Mollusca.' It occupies the country lying between 

 the Stour and Deben, as well as the left bank of the estuary of the 

 Deben ; and its richest development in the yield of mollusca is on 

 either side of that estuary. In physical structure it is unlike that 

 of Walton (which is principally stratified horizontally, and due to 

 subaqueous deposit), and possesses for the most part that highly 

 oblique bedding which I now believe can have originated only in 

 heach-action. In this crag we have the intermingling of the greater 

 proportion of the Walton fauna with that northern fauna which 

 forms the preponderating or characteristic feature of the succeeding 

 horizons, to which I have hereafter to refer. 



In the Sutton Crag the following species, common or not un- 

 frequent at Walton, have never been found by me except under the 

 suspected character of derivatives from the Coralline Crag— Ovula 

 spelta, Columhella sulcata, Nassa elegans, Natica catenoides, If. multi- 

 punctata, Nucula Icevigata, Cardium ParMnsoni, and others ; while 

 on the other hand the following species, foreign to the Walton deposit, 

 occur, viz. Tritonium antiquum (dextral var.), Cardium Groenlan- 

 dicum, Leda lanceolata, L. limatula, Cardium angustatum, Tellina lata, 

 T. obliqua, T. proetenuis, Mactra ovalis, Mya arenaria, M. truncata, 

 and others. The peculiarly northern forms, however, so charac- 

 teristic of the higher horizons, are comparatively rare, and the whole 

 facies of the fauna presents the appearance of that transitional state 

 which is intermediate between the more southern or Mediterranean 

 fauna of Walton and the more peculiarly British and northern aspect 



