324 KEPOET — 1892. 



Habitats. Fossils on which the various species were fotmd. 



1. Bonrgueticriniis ellipticus, Mill. 

 1'. Cardiaster pilula, Lam. 

 ■ 3. Micraster cor-anguinum, Leske. 

 4. Echinoconus, sp. 

 6. Rhj'iichonella octoplicata, Sow. 



6. Ostrea vesicularis, Lam. 



7. Inoceramus, sp. 



8. Belemnitella mucronata, Sch. 



9. ,, quadrata. Defr. 



10. Echinocorys vulgaris, Breyn^ A nancJii/tes ovaius. Leslie. 



VII. PoLYzo.v, Berecshire and Buckinghamshire. 



In Mr. W. Whitaker's ' Geology of London and Part of the Thames 

 Valley,' vol. i., p. 76 (1889), will be found remarks on the fossil contents 

 of the various pits in Beikshire visited by Mr. Rhodes. In the Twyford 

 and Maidenhead districts Chalk was quarried in many places, and Mr. 

 Rhodes collected fossils from such pits as were still in use. A list of 

 fossils procui-ed from these pits will be found at pp. 79 and 80, amongst 

 which are several Polj-zoa. The Chalk in all the pits — of which locali- 

 ties are given — is characterised by certain fossils, which are either rare 

 or absent in the beds below. These are : — 



Bourgueticrimis (? ellipticus), Miller. 



Ciilaris peronata, FoT-bes. 



Micraster cor-anguinum, Leske. 



Ostrea acutirostris. Nils. 



Pecten nitidus, Mant., with many Polyzoa and Serpulce. 



There can be little doubt, says Mr. Rhodes, that this Clialk belongs to 

 the zone of Micraster cor-avguiuuvi, whilst that with the spongeous flint 

 (Cookham Dean) may be referred to the zone of Micraster cor-testudi- 

 narium (p. 76). 



In a pit quarried on the Buckingham side of the Thames is a layer of 

 greyish gritty Chalk in blocky masses resembling Totternhoe stone, with- 

 out flints, in which are Belemnitella quadrata and Ostrea acutirostris ; and 

 the presence of these fossils, with a comparative scarcity of flints, suggests 

 a correlation of this Chalk with the Margate Chalk of the zone Marsupites 

 testudinnrius (p. 1'?). 



The Polyzoa, partially and fully identified by Mr. Rhodes, are as 

 follows: — 



Diastopora, sp. Idmonea and Escharina sp., Littlewick. 



Diastopora, sp. only, Bisham. 



Entalophora and Membranipora, Pinkneys. 



Proboscina angustata d'Orb., ' Terr. Cret.,' pi. 632, Marlow. 



ramosa, d'Orb., ' Terr. Cret.,' pis. 632, 633, Marlow. 

 Entalophora cenomana, d'Orb., ' Terr. Cret.,' pi. 618, Waltham. 

 Semicschara arborea, d'Orb., ' Terr. Cret.,' pi. 710. 



VIII. Polyzoa, Hertfordshire and Middlesex. 



Several Chalk pits in the neighbourhood of Rickmansworth and Wat- 

 ford were examined by Mr. Rhodes, and with very satisfactory results as 

 regards Polyzoa. In all probability the Chalk of these pita also is in 



