XXVIl1 SUPPLEMENT TO THE CRAG MOLLUSCA. 
the accompanying cut from that paper of the section afforded by Kelsea Hill in 1867 is 
given. 
KELSEA HILL BALLAST PIT IN 1867 (Extreme height of section, 35 feet). 
West Face. Angle of Pit. South Face. 
1. Sand and gravel with Marine shells and Cyrena fluminalis (d of the Yorkshire 
coast section). 2. The Hessle Clay (e of the coast section). 3. Newer Gravel (fof 
the coast section). N.B.—The Clay, No. 2 at the extreme left of the section, is probably 
only a subaérial wash down of No. 2, which is im siéé in the centre of the section. 
4. Talus. 
The Kelsea gravel is overlain by a clay containing some stones and boulders 
(mostly small), which, from its identity with that of the well-known Hessle section, has 
been termed “the Hessle clay.’ ‘This clay is shown in the preceding coast section under 
the letter e, and there wraps the whole of the denuded edges of the purple clay to which 
the Bridlington bed belongs like a cloth, and is underlain irregularly by beds of sand and 
gravel called “ the Hessle sand” (d) that are presumably identical with the gravel and 
sand of Kelsea Hill. This presumption accords with the molluscan contents of the gravel 
when contrasted with those of the Bridlington bed; for at Kelsea there is not only an 
absence of the specially arctic and American forms which characterise the Bridlington 
bed, but also of those characteristic crag forms Zellina obliqua and Nucula Cobboldie. 
Paull Cliff is on the Humber; but it has been nearly destroyed in making the battery 
at that place. The sand and gravel of Paull, there can be little question, belongs to the 
Hessle sand (d), as it has yielded similar shells to the Kelsea gravel, Mr. Prestwich finding 
in it the Cyrena; and it rests on either a or e. 
The Hunstanton gravel resembles in its palaeontological aspects the Kelsea Hill bed 
in consisting entirely of living species, and none but those inhabiting British seas have 
yet been obtained by us from it.! It is not, however, overlain by anything answering 
to the Hessle clay, which caps the Kelsea gravel, that clay not having been traced further 
1 This gravel and that at March was first described by Mr. Seeley in the ‘ Quarterly Journal of the 
Geological Society,’ vol. xxii, p. 470, but two shells that he names from Hunstanton, Nassa reticosa and 
Tellina obliqua, have not been found by others, and are believed to be Nassa reticulata, and the large, 
rounded form of 7’. Balthica, both of which occur there. The shell also, called by him Astarte crebricostata, 
from March, is most probably 4. borealis, which occurs plentifully there, and which is a somewhat abnormal 
form of this shell, and approaching 4. erebricostata. We have not yet been able to find Tellina prowima 
given by him from March, nor to recognise anything like the Glacial clay there, the clay with some minute 
fragments of chalk, which underlies and seems connected with the gravel, being, we consider, of Post- 
glacial age. 
