THE 'DERIVED' FOSSILS. 33 



f/ranidatum,. Phill.?; Solarium Neocomiense, d'Orb. ?; Trochus sp. 

 (also at Shanklin, M.); Trigonia Vectiana, Lycett; Trigonia, sp. ; 

 Mytilus lanceolatus, Sby.; Thetis minor, Sby.; Perna Mulletti,Sby.; 

 PernaRicordeana,d'Or\).; Pecten orbicular is, Sby.; Cucullcea errans, 

 Keeping ; Cucullcea Donningtonensis, Keeping. There is good 

 reason to believe that Terebratula ovoides, Sby. and T. ovoides var. 

 rex, Lankester, likewise belong to this fauna, although at Upware 

 they are commonly found in a thoroughly phosphatised condition. 



So crowded are the fossils in this rock that one small block of 

 it from Upware, now in the Woodwardian Museum, exhibits speci- 

 mens of Pecten orbicularis, Sby., Thetis minor, Sby., a small triangu- 

 lar bivalve, and Trigonia Vectiana, Lye. At Potton these blocks 

 have been found with many of the same species, and in addition, 

 FissurellaNeocomiensis,d'Orb.; Pecten striatocostatus, Goldf.?; Lu- 

 cina; Leda; Cardium? small species; and Fossil-wood, with the 

 woody fibres beautifully seen. 



At Hunstanton large masses of exactly similar rock as big as 

 large cannon-balls are found in a zone beneath the carstone and above 

 the clay (see Wiltshire, Quart. Journ. Geol. Soc. Vol. xxv. p. 188). 



From these blocks we have in the Woodwardian Museum the 

 following species: Hamites or Ancyloceras, small species with a 

 double row of spines along the back ; Scalaria; Tornatella; Sola- 

 rium Neocomiense, d' Orb.; Pecten orUcularis, Sby.; Nucula; Lucina; 

 Cardium subhillanum, Leym.; Cythercea Orbigniana; Goniomya 

 Rauliniana, d'Orb.; Scrobicularia phaseolina, Phill.; Corbula; and 

 Pholadomya, and other species from the same rock are probably 

 included in the list given by Mr Etheridge in the paper by the 

 Rev. T. Wiltshire already cited. 



The similar rock above referred to as occurring in the Isle of 

 Wight is found in the upper part of the Lower Greensand at 

 Horseledge, Shanklin, and at Blackgang Chine, and here it 

 contains, like the Upware blocks, the casts of Thetis minor. 

 The palaeontological resemblances of these two rocks are however 

 not so great as the lithological, for out of thirty species only seven 

 are known to be common to the two. The fragments of fossil- 

 wood are much alike in all these places. 



Again, a very similar dark grit occurs in the Uppermost Lower 

 Greensand at Folkestone, containing Thetis minor and other small 

 bivalves, Mytilus and fossil-wood. 



K. 3 



