part 4] juEAssic CHEOis^OLoaT. 393 



sequences), as is known from other areas, and where these really 

 occur is a matter of some surmise : — ■ 



falciferum, 



bouchardi, 



murleyi, 



granulosa, 



Alaria, 



Thecidella rustica, 



Leptseiia, 



glohulina, 



spi7iatutn. 



(B) Additional Details concerning the Junction-Bed of 

 Thorncotnbe Beacon. 



One of the most remarkable features of the Junction -Bed is 

 that it may always spring surprises in the matter of its faunal 

 contents. This apparently arises from the fact that fragments of 

 so many different beds have been preserved. These fragments are 

 in many cases quite small, and in other cases it would seem that 

 the fragments themselves were disintegrated, but that some of 

 their contents became incorporated in other strata. 



During one visit I was fortunate enough to find a small block 

 in which were preserved various specimens of BhynclioneUa 

 serrata and like forms (yPrionorliyncliia spp.) in a sort of pale 

 Marlstone-liock matrix. This presumably is only a fragment of a 

 once widespread bed. One may search many of the ordinary 

 Marlstone blocks under Thorncombe without finding it. Walker 

 found many specimens of Hh. serrata at the temporary exposure 

 near Bothenhampton. Moore says that near Ilminster (Somerset) 

 the species is found only at Moolham ^ ; these Somerset and Dorset 

 localities are, I think, the only places where the fossil is known in 

 England, and consequently destruction of this bed must have been 

 considerable. On the Continent a species alhed to Itli. serrata — 

 Frionorliyncliia quinqueplicata (Zieten) is found in Wiirtemberg, 

 indicating, perhaps, that an original spread of the bed was to that 

 country. This species is also found in England with Rh. serrata. 



From the same block I obtained a remarkable Terebratulid — 

 somewhat of Terelratula punctata style, but anteriorly sulcate, 

 and therefore an inverted form. Further search for other blocks 

 to yield another example was quite unsuccessful. During my visit 

 in 1920 I could not find a single block showing the serrata bed. 

 Mr. Jackson, however, has another inverted example, though it 

 is a different species. I hope to deal with these in a future 

 palseontological portion of this paper. 



Rhynchonellids, small, rather fiat, with few coarse plicse, were 

 found in this bed : such forms have passed by the names Bhynclio- 

 neUa egretta, RJi. fallax, but the identifications are open to doubt. 

 Also from this block I extracted examples of (or allied to) 



1 VII, p. 164. 



