200 



So far as I have been able to discover, the species which, 

 of all these, extends the furthest downwards is Gresslya 

 abduda, which appears in the Jurense-zone of the 

 Upper Lias. In the Opalinum-zone of the lowest «Dogger'> 

 (Bajocian), Gresslya peregrina and Tancredia angulata 

 appear; in the Murchisonæ-zone, Ästarte elegans and 

 Gresslya gregaria; in the Sowerbyi-zone, Pholydomya 

 angustata', in the Humphriesianum-zone, Ostrea eduli- 

 formis; while in the Great Oolite (Bathonian) Trigonia 

 undulata appears for the first time. 



In the Parkinsoni-zone of the Upper Bajocian the 

 following species die out : Astarte elegans, Gresslya gre- 

 garia and Gresslya abducta, although the last of these 

 may possibly pass up into the Bathonian. In the Ba- 

 thonian, Tancredia angulata dies out. Ostrea eduliformis 

 and Trigonia undulata die out in the Macrocephalus- 

 zone of the Callovian , Pholadomya angustata in the 

 Perarmatum-zone of the Corallian and Gresslya peregrina 

 in the Plicatilis-zone of the same. 



If then we may venture to correlate the Middle- 

 European distribution of fossils with that of East-Green- 

 land, it would seem that the fossils in question must 

 have been derived from strata of an age intermediate 

 between the Upper Bajocian and Lower Bathonian. 

 A very coarse-grained brown crinoid - sand- 

 stone, occurring at about 1676 feet (525 metres) above 

 sea-level, a local development of b), contained: — 



Pentacrinus sp. cf. Andreœ, de Lor., many pieces 

 of stems and cirrhi, a few arm-fragments and 

 some portions of the calices. 



Lima sp., one impression. 



Ostrea eduliformis, Schloth., a few specimens. 



Belernnoidea-frsLgments. 

 Pentacrinus Andrece occurs in the Bathonian. 



