GRAPTOLITES OF NEW YORK, PART I 735 



ADDENDUM 



cARYocARis Saltci' aod DAwsoNiA Nicholsoii 



Associated Avith the graptolites of the Deep kill and Nonnanskill beds, 

 we have found numerous small variously shaped bodies Avhich consist of a 

 substance that is similar to, but as a rule, more tenuous than that of the 

 graptolites. For one group of these bodies the generic term, Caryocaris, has 

 been proposed by Salter [1863, p.l89], for another that of Dawsonia by 

 Nicholson [1873, p.l39]. The former were considered ci'ustaceans, the latter 

 "ovarian capsules" (" grapto-gonophores ") of grajjtolites. Gurley [1896, 

 p.85ff] has maintained that both are graptolites. As, at least, in regard to 

 one group, the Dawsonias, our material tends to verify his observations, we 

 have appended here the descriptions of the representatives of both groups 

 occurring in the lower graptolite beds ; but Avish it understood that we con- 

 sider their taxonomic position not yet determined. 



The substance and texture of the test of all these forms is one of their 

 characteristic features by Avhich they can be readily recognized. It is 

 apparently of a chitin®us nature, but mostly thinner than that of the 

 graptolites, of less luster, possessing often a light purplish tint, also observed 

 by Etheridge, WoodAA^ard and Jones^ in regard to Caryocaris 

 Avrightii, and above all an extremely delicate, irregular corrugation or 

 wrinkling, the A\"rinkles often assuming the appearance of scales or regularly 

 overlapping tiles [pi. 17, fig.17]. This corrugation, AA^hich is never found so 

 strongly developed on the periderm of the graptolites, is an indication of 

 the thinness and flaccidity of the test of the forms under discussion. It 

 often appears like a shri\'eling, but is in most cases clearly superin- 

 duced by the incipient and minute cleavage or slipping of the rock. Its 

 character is indicated on the figures, Avhich also shoAv that the AA-rinkles 

 cross the specimens in no definite direction, but that the latter depends 

 entirely on the accidental position of the specimens to the cleavage planes in 

 the rock. 



^Kep't of the Committee on the Fossil Phyllopodaof the Palaeozoic Eocks. 1883, p.7. 



