330 



M. F. L, COmSTET OX THE UPPER CRETACEOUS SERIES 



organic matter which the Brown Phosphatic Chalk contains. It is 

 to this substance that one must attribute the following fact, which 

 has been pointed out by Professor Melsens of Brussels * : — 



" The carbonic acid which is disengaged when the rock is treated 

 with hydrochloric acid has a peculiar odour, reminding one of the 

 smell of a marsh ; when the disengagement of carbonic acid has 

 ceased, and the acid liquid is heated, this marsh odour becomes 

 stronger, and forcibly recalls the smell of the mud of ponds/' 



In the subdivision d^ a good many remains of Saurians and of 

 Pish have been found, consisting chiefly of teeth and vertebrae, but 

 the abundance of marine shells gives a very remarkable palaeonto- 

 logical character to this deposit. A large number of specimens, 

 such as the oysters, are found with their two valves united. The 

 most common species are : — 



Ditrupa Mosse, Bronn, sp. 

 Belemnitella raucronata, Schl., sp. 

 Baculites Faujasi, LamJc. 

 Pecten pulchellus, Nils. 



cretosus, Befr. 



cicatrisatus, Goldf. 



Janira substriato-costata, cVOrb. 

 Lima semisulcata, Goldf. 

 Avicula c£erules(fens, Nils, 

 Ostrea santonensis ?, d'Orh. 



lateralis, Nils. 



larva, Lamk. 



lu]->ata, Lamk. 



vesicularis, Lamk. 



acutirostris, Nils. 



curyirostris, Nils. 



podopsidea, Nyst. 



Ebjucbonella octoplicata, Sow., sp. 



subplicata, d' Orb. 



plicatilis, Sow. 



Terebratula semiglobosa, Sow. 



carnea, Sow. 



■ Sowerbyi, Hagenow. 



Terebratulina striata, Wahl., sp. 

 Terebrirostra Davidsoniana, Be Byckh. 



plicata, Bosquet. 



Terebratella Humboldti, Hagenow. 

 Argiope Davidsoni, Bosquet. 

 Trigonosenius elegans, Konig. 



Palissi, Woodw., sp. 



Thecidea papillata, Bronn. 



recurvirostra, Befr. 



Crania Parisiensis, Befr. 



antiqua, Befr. 



egnabergensis, Betzius. 



Eequienia ciplyana, Be Eyck. 

 Catopygus fenestratus, Agass. 

 Oardiaster anancbytis, d'Orh. 

 Cidaris Faujasi, Besor. 



The thickness of the subdivision cf is from 20 to 30 feet. 



d^. This subdivision is composed of a coarse phosphatic calcareous 

 rock identical with that of the subdivision cZ^, but with numerous 

 nodules of flint, isolated or arranged in continuous beds. This 

 flint is brown in colour, often imperfect and with hoUow 

 spaces. It contains sometimes from 10 to 14 per cent, of 

 phosphate of lime. The fossils are less common than in the 

 bed <:?", but they belong to the same species f- Besides, in d^ 

 numerous siliceous sponges are found. 



These flints show by their texture that they also have had an 

 organic origin. 



* BuU. Acad. Eoyale de Belgique, 2^ ser. vol, xxxviii. 



t In March 1885, the nearly entn-e skeleton of a Saurian, measuring with the 

 tail 50 feet in lengtb, was found at Mesvin in the beds of phosphatic and flinty 

 chalk d^. This gigantic fossil now forms part of the collection of the Eoyal 

 Museum of Natural History of Brussels. It has been described by M. Dollo, 

 who has given it the name of Rainosawms Benmrdi. 



