Vol. 62.] PHOSPHATIC CHALKS OF WINTEEBOURXE AKD BOXFORD. 505 



section. They occur in all the Phosphatic Chalks of this neighbour- 

 hood, as well as in those of Taplow and Lewes. 1 It is noteworthy 

 that, of the foraminifera, the Globigerinidae are by far the most 

 frequently preserved in this way, although casts of a Cristellaria 

 (probably Or. rotulata, Lam.) are prominent in some samples. 



Faunal Succession. — The most important fossil observed in 

 bed (1) is Marsupites testudinarius, which is represented, as usual, 

 by scattered plates and brachials. Remains of this crinoid occur 

 throughout the bed, but are most common between 1 and 2 feet 

 below the top, where there are probably about a dozen of the plates 

 per cubic foot of chalk. 



In the nodular band (2) the same form occurs, and with it an 

 abundance of Ostrea vesicularis and of bits of Inoceramus, remains 

 of Spondylus spinosus (?), and casts of sponges. 



The friable chalk of bed (3) swarms with remains of Ostrea 

 vesicularis, 0. Wegmanniana, and other oysters, and pieces of 

 Inoceramus also are very abundant. In the lowest part of this bed 

 Jlarsupites-jAates are still fairly common, but they become scarce 

 about 8 or 9 inches up, and have not been found higher than 

 2| feet above the base. At the horizon where Marsupites becomes 

 scarce, we obtained one very slender guard of Actinocamax verus, 

 and noted the first appearance of A. granulatus. 



The guards of the latter belemnoid are sparingly represented 

 in the succeeding 4 feet of bed (3), and appear to be evenly dis- 

 tributed therein. They are rather below the average size, show a 

 feeble but distinct granulation, and have an alveolar depth between 

 one-fifth and one-seventh of their length. Though usually broken, 

 they are rarely much decayed. Ecliinocorys scutatus, which we 

 have seen only in small fragments in the lower beds, is often well- 

 preserved here. Most of the examples collected by Miss Baylis 

 and by us are of the slightly-blunted pyramidate or angulate 

 form and medium size (length = 60, height = 42 mm.) usually met 

 with in the Marsupites-Band. in Berkshire, North Wiltshire, and 

 North Hampshire ; but in the upper half of this bed a smaller and 

 more squat mutation of the -pseudo-pyramidatus variety is occa- 

 sionally seen. Micraster cor-anguinum var. rostratus is common 

 in the higher layers ; teeth of Corax, Lamna, and Oxyrhina 

 are not infrequently encountered ; and Spondylus latus occurs 

 throughout. 



In the yellow rock-band, bed (4), Actinocamax gramdatus and 

 Echinocorys scutatus become very common. Here the former is more 

 markedly granulated, but can rarely be extracted in an other than 

 fragmentary condition. The pyramidate variety of Echinocorys 

 scutatus present in the softer chalk below is almost completely 

 replaced by stunted forms, which are better seen in the succeeding 

 bed (5). Casts of the sponges Ventriculites radiatus, V. infundi- 



1 See A. Strahan, Quart. Journ. Geol. Soc. vol. xlvii (1891) p. 362, & vol. lii 



1896) p. 465.' 



