608 MR. C. B. WEDD ON THE [NoV. 1 898, 



The crystalline bands in 2 (6) were crowded with Thecosmilia 

 evidently in the position of growth. In most instances noticed, the 

 main stem was vertical or nearly so ; it seemed that only horizontal 

 sections of the coral had been preserved, in length equal to the 

 thickness of the crystalline layers. 'No Thecosmilia was found in 

 2 (c), 3, or 4, in the broken crystalline bands, the corals here being 

 Thamnastrcea or Isastrcea, and probably RhabdophylUa, represented 

 by tubes filled with marl. It was observed that the corals in the 

 lower beds contained in the marl were preserved somewhat differ- 

 ently from those in the liag, the septa here being preserved in 

 calcite, and the Thecosmilia never occurring as hollow casts like the 

 Montlivaltia in the itag. 



An estimate of carbonate in the marl 2{c) gave the equivalent of 

 only 53 per cent, of carbonate of lime. The bed (3) of the section 

 has a superficial resemblance to a soft grit. Ossicles of the cirri 

 and pinnules of Pentacrinus are the chief constituents, together 

 with stem-joints and occasional calyx-plates. Corals (in the crystal- 

 line blocks), Cidaris Jlorigemma, Ostrea gregaria, Exogyra nana, etc. 

 were noticed. The crinoids are wholly disintegrated, two or three 

 joints being seldom found united. 



The white rubbly limestone (4) is not like either the Eag or the 

 oolite of Up ware. It is possibly conglomeratic, and has the appear- 

 ance of coral-detritus partly dissolved. This bed and the one below 

 are certainly suggestive of formation in shallow water on the slope of 

 a coral-reef. No certain trace was found in this limestone of the 

 pisolitic or oolitic structure of the Upware oolite. It is difficult, how- 

 ever, to draw a line between rolled and perhaps slightly coated joints 

 of crinoids and the first stages of the true pisolite. I have often 

 found the latter to consist at Upware of ossicles and small stem- 

 joints oi Pentacrinus, fragments of echinoid spines, and even occasion- 

 ally small gasteropoda, the last-named preserved as internal casts in 

 the pisolite, all coated with a calcareous growth. Sometimes two 

 or three smaller oolitic grains are cemented together and coated over 

 with this growth, producing an irregular pisolite. I have not 

 succeeded in finding Girvanella in this growth, but there is no 

 reason to doubt that it might be found. That the Upware pisolite 

 is a true pisolite, and not merely formed by an agglomeration of 

 rounded shell-fragments, is certain; especially as scarcely any trace, 

 if any at all, of arragonite-shells is preserved in the Upware rock, 

 all such being represented merely by casts. 



As mentioned above (p. b06), it had been decided to sink a well 

 close to the section last described. The work was, however, delayed 

 for several months, and when it was carried out I was unable to be 

 present. By the kindness of the well-sinker and the landlord of 

 the Inn, I was informed when the work would be begun, and asked 

 Messrs. H. H. Thomas & G. McFarlane, of Sidney Sussex College, 

 to examine the well. They were good enough to make several 

 journeys to Upware during the progress of the work, and to them 

 I am indebted for the following particulars. The well was sunk 



