Yol. 57.] UPPER GEEEN8AND AND CHLOEITIC MARL OF WILTSHIRE. 109 



Of these beds, jSTo. 1 is similar to the lower sandy part of the 

 Chloritic Marl with Stauronema Carteri at Maiden Bradley, but is 

 rather less tough, owing probably to its occurrence at the surface 

 and consequently its more decomposed and decalcified condition. It 

 passes down into the still less calcareous sand below. 



No. 2 is a sharp greenish sand containing quartz-grains of 

 various sizes, some very small, some large, just as in the bed 

 above. Here and there the sand is concreted into hard lumps, 

 but no derived phosphatic nodules occur in it. Casts of Ammonites 

 varians in a pale yellow calcareous material occur plentifully ; they 

 are often so decomposed as to fall to pieces, but if got out carefully 

 they harden greatly in drying. Brachiopods are abundant, espe- 

 cially Rhynchonella grasiana and Rh. dimidiata, with Terehratula 

 biplicata and T. arcuata. Terebratella pectita occurs as well, and 

 Catopygus columbarius is common. This bed has hitherto been 

 regarded as the highest part of the Upper Greensand, but it does 

 not seem to correspond exactly with any particular layer at Maiden 

 Bradley. 



No. 3 we do not hesitate to regard as the equivalent of the 

 brown sand and nodule-bed at Maiden Bradley. There is 

 a sudden transition between, this and the bed above, but it is due 

 rather to coloration than to change in lithological character. It 

 forms a layer of yellowish-brown sand, which contrasts with 

 the greenish-grey sands above and below ; its thickness varies from 

 4 to 6 inches,, and it contains at intervals lumps of sand concreted 

 by ferruginous matter, with which there are a few phosphates, but 

 there is no layer of phosphatic concretions as at Maiden Bradley. 

 Possils, however, are more plentiful than in the sand above, and 

 include most of the species common at Maiden Bradley : Catopygus 

 columbarius is very abundant; the ammonites are chie^j Ammonites 

 varians in a brownish calcareous phosphate; Fecten asper is common ; 

 and bryozoa are also plentiful. 



(4) The brownish sand passes down into a greenish sand, in 

 which are numerous calcareous concretions like the Corn stones of 

 Maiden Bradley, only they are yellowish outside and not phos- 

 phatized. These cornstones are scattered thickly through 6 to 

 10 inches of sand ; but they lie at various angles, and some of them 

 have their longer axis nearly vertical. Many bear small attached 

 oysters, so that they seem to have been indurated before they 

 were brought into their present position, and yet they , show no 

 signs of long exposure or rolling. Some fossils occur in between the 

 cornstones, such as Pecten asper and Spondylus striatus ; Terebratulce 

 and Rhynchonella grasiana are found in great abundance ; Catopygus 

 columbarius is not uncommon, but Terebratella pectita is rare. 



(5) The transition from the Cornstones to the sand below is 

 sudden, and there is an equally sudden decrease in the abundance 



