GRAPTOLITES OF NEW YORK, PART 1 511 



Giiricli [1896, p.960] had, at the same time, by his study of the Polish 

 graptolite horizons arrived at the conclusion that the monograptids, populating 

 these horizons, had belonged to the plankton. He cites as his arguments the 

 geologic distribution of the graptolites, their mode of preservation in the rock, 

 their appearance in heteropic beds and their accumulation in such beds, which 

 for other reasons also must be considered as formations of the deeper sea. He 

 finds a verification of his views in the writer's observations on Diplograptus. 



The former mode of existence of fossil marine animals has been 

 thoroughly studied by Johannes Walther [1897]. The graptolites have 

 thereby excited his special interest, because, as a group of most excellent 

 index fossils, they must have lived under conditions greatly different from 

 those indicated by the mode of occurrence of the majority of fossils. He finds 

 that they were most pronounced facies animals, being bound to thinly bedded, 

 carbonaceous shales. The connection of the graptolites with a distinct facies, 

 it is stated, would argue for the conclusion that the graptolites belonged to 

 the sessile benthos, being attached in some fashion to the bottom of the sea, 

 as has been claimed by Jaekel. The author rejects this conclusion on the 

 ground that in that case they should occasionally be found to pass the bed- 

 dino- planes, while, as he was informed by Professor Lindstrom, they are never 

 found in that position in the Swedish graptolite shales, the sandstones or 

 limestones. The clue to the solution of the apparent contradiction of the 

 occurrence of the graptolites in a characteristic facies and on the bedding 

 planes was, as he states, furnished to him by Professor Lapworth, who prepared 

 a statement of his views, published in the same paper. 



We can not refrain from enumerating here the important conclusions of 

 this authority on matters referring to graptolites. 



Lapworth found, during his extended researches of the English grapto- 

 litiferous beds, that the typical or rhabdophorous graptolites occur in all sedi- 

 ments, but are most frequent in such deposits as possess a strong admixture of 

 carbonaceous matter, and that the number of genera, species and individuals 

 increases in direct proportion (1) to the quantity of carbonaceous matter. 



