270 W. J. Sollas — On Greensand Foraminifera and Sponges. 



were adherent softer animal tissues, are often completely imbedded 

 in it. So, also, the sternal surfaces of Crustacea are buried in Copro- 

 lite, while this is seldom the case with the exposed surfaces of their 

 carapaces. Other examples might be adduced, and, indeed, instances 

 of the same fact multiplied almost without end. An additional 

 argument on this point is furnished to us by analyses, which prove 

 as a general result that organic matter still exists in the Copr elites, 

 and that sometimes to the extent of 5 per cent. This makes itself 

 evident by a smell of burnt horn when the nodules are heated, and by 

 an odour like petroleum when they are dissolved. Not only in the 

 Greensand, but in various other formations, this connexion of Copro- 

 lite with animal matter has been observed. It is strikingly notice- 

 able in the Coprolites of the Eed Crag, which have been derived 

 from the London Clay, as those of the Greensand from the Gault. 

 The palates of Myliohates are found in the Crag with their biting 

 surfaces exposed and bare, whilst their attached surfaces are deeply 

 incrusted with the Coprolite. So, also, with the teeth of Carcharodon, 

 Otodus, and their allies ; great balls of Coprolite surround their 

 bases, but leave their blades perfectly clean. The incrusted Crustacea 

 of the Crag are sometimes, however, completely inclosed in Copro- 

 lite. Analyses here, as in the Greensand, indicate the presence of 

 organic matter. 



Various other deposits contain nodules, which present characters 

 more or less in accordance with the foregoing ; but most interesting 

 are the forms of the Lower Silurian of Canada,^ which offer striking 

 illustration of the fact we have been adducing. Here the phosphatic 

 matter incloses Zingula, and fills casts of Pleiirotomaria and Holopea. 

 When heated it evolves ammoniacal water, with an odour like burnt 

 horn. It almost always contains fluorine, and is sometimes sur- 

 rounded on the exterior by iron pyrites, as also are some of our 

 Greensand forms, a fact of significance in relation to the formation of 

 these bodies, and strictly paralleled by the similar incrustations 

 sometimes found around certain flints. Analyses made of these 

 Silurian Coprolites always yield a large per-centage of organic 

 matter. 



This connexion between Coprolites and organic matter, which 

 derives support from almost every fact which an investigation of 

 these forms brings to light, furnishes us with a basis for a scientific 

 definition of the term. The original meaning of the word Coprolite 

 has, in reference to our Upper Greensand forms, long ago been washed 

 out, and has become replaced by a perfectly distinct signification in- 

 dicating the phosphatic fossils of our formation, or more restrictedly 

 such of them as are of obscure or uncertain origin. The word is not 

 a good one, but in face of its almost universal adoption one cannot 

 hope to exterminate it. Flints are scarcely likely to acquire a name 

 after some long Greek derivative, and Coprolites could hardly do 

 BO a second time. As one is not at liberty to choose a new name for 

 these bodies, I propose to limit the application of the old one, and 

 to call those bodies Coprolites which are produced by the phosphatic 

 1 Geological Survey of Canada, Editiou 1863, p. 461. 



