PRESTWICH — WOOLWICH AND READING SERIES. 



103 



Caidium Plumsteadiense, Sow. 

 Cerithium variabile, Desk. 



Lunnii, Mor. 



Bowerbankii, Mor. 



Cyrena deperdita, Sow. 



cordata, Mor. 



cuneiformis, Fer. 



intermedia, Mell. 



tellinella, Desk. 



Fusus latus, Sow. 



gradatus, Sow. 



planicostatus, Mell. ? 



Melanopsis ancillaroides, Desk. 



' buccinoides, Fer. 



Melania inquinata, Desk. 

 Modiola Mitchelli, Mor. ? 

 Murex foliaceus, Mell. 

 Natica glaucinoides, Sow. 

 Neritina consobrina, Fer. 



Neritina globulus, Desk. 



pisiformis, Fer. 



vidua, Mell. ? 



Nucula fragilis, Desk. 

 Ostrea Bellovacina, Desk. 



tenera, Sow. 



Hydrobia Parkiiisoni, Mor. 



Websteri, Mor. 



Pectunculus terebratularis, Lam. 



Pholas ? 



Planorbis hemistoma, Sow. 



Teredina personata, Besh. 



Teredo antenautae, Sow. 



Teeth of Lamna. 



Scales and teeth of Fishes. 



Crustacea (Cancer). 



Small seed-vessels (Carpolithes ?). 



Cythere &c. (Entomostraca,list, p. 120.) 



Small Bryozoa. 



There are also two undescribed sections to which I must allude, 

 as they present several peculiar and interesting features. The first 

 is one by the side of the new road leading down the hill from 

 Charlton : it is taken from two or three small pits, but the sequence 

 is perfectly clear. On the top of the hill is the Blackheath pebble 

 bed ; then follows — 



(PI. I. Diag. A, Loc. sect. 24.) 



Feet. 



Light yellovf sands striped with clay 12 



Light yellow sands with thin seams of iron sandstone ... 5 



Dark grey clay with shells 6 



A. Layer of hard concretionary limestone 2 



a. Pebbly green sand 10 



Thanet Sands. 



The beds " a, h, d, and e" are non-fossiliferous, but the clay bed 

 " c " contains the same organic remains as at Woolwich. 



The blocks of argillaceous limestone " b " are concretionary masses 

 of frequent occurrence in this neighbourhood. They are exceedingly 

 hard and tough, and contain here no organic remains. (This stratum 

 is more fully developed beneath London, and is often a source of con- 

 siderable difficulty to the well-digger.) 



But the most important feature of this section is the occurrence 

 on the upper surface of a thin seam of iron sandstone, interstratified 

 in the upper part of " d" of well-marked ripple-marks, the ridges 

 of which run nearly E. and W. This is the only instance I have 

 met with of a ripple-marked surface in the Tertiary series of the 

 London district. 



The second section is at the entrance to the Tunnel on the S. side 

 of Blackheath, and differs in several points from the preceding 

 Charlton section. 



