Vol. 69.] DERIVED CEPHALOPODA OP THE HOLDERNESS DRIFT. 175 



very frequently. However, during the past four years we have 

 been more successful. It has been found, as was to be expected, 

 that scattered examples of the species sought for occur in the cliffs 

 of Holderness. It is well known that large masses of travelled 

 Liassic shale occur in Filey Bay. Now these are from the very beds 

 in question, and have already yielded a few representative trophies. 

 They will probably yield many more when properly worked. 

 I have been informed that the most fossiliferous mass lies far out 

 on the foreshore, and can only be reached at certain states of the 

 tide and beach-material. It has never been my lot to see it 

 exposed ; therefore our collection still lacks many of the beautiful 

 pyritic ammonites so characteristic of the zone, and the appended 

 list is consequently at present very weak in representatives of this 

 zone. 



Capricornus Beds. 



There is little more to be said about the cephalopods of the 

 Capricornus Zone than that its characteristic name-fossil is found, 

 as usual, in hard nodules which might very well have been swept 

 from the Yorkshire exposures in the north. 



The stout forms of the Liparoceras-striatum group, and also 

 examples of the genus Lytoceras, which should have their repre- 

 sentatives in these beds, appear to be rare in the North Yorkshire 

 Lias. This is also true of the Glacial Drift. I know of only one 

 example of the former group : this I have provisionally entered on 

 the list as Liparoceras striatum (']). This specimen was only noted 

 by me quite recently, during a visit to the Sheffield Museum, 

 where it now is, having been purchased from Mr. Morfitt at 

 Atwick, in Holderness. Again, I know of only one specimen of 

 the genus Lytoceras from the Drift : that also was found by the 

 above-named collector. 



Margaritatus and Spinatum Beds. 



Along the shore and in the cliffs there are many shelly boulders, 

 both from the Margaritatus Zone and from that of Paltopleuro- 

 ceras spinatum. 



Some of these are exceedingly tough, although some are quite 

 brittle, owing to the presence of numerous lamellibranchs. They 

 are good hunting-ground for ammonites, and not infrequently one 

 will yield at least three species. In consequence, we have numerous 

 specimens which have not yet been submitted to Mr. Buckman, and 

 have been entered in the appended list (p. 181) under the local 

 comprehensive terms margaritatus and spinatum. The boulders 

 from the Spinatum Zone are very numerous among the beach-stones. 

 They are also very obvious, because of their coating of yellow or 

 reddish hydrated oxide of iron. 



It is interesting to know that spinatum boulders are also found 

 in the Drift of Denmark. 



