THE EURYPTERIDA OF NEW YORK 385 
APPENDIX 
Remarks on Beltina danai Walcott 
1899. Beltina danai Walcott. Geol. Soc. Am. Bul. ro: 238, pl. 25, 26; pl. 27, 
fig. 2-6 
Ever since the publication of the work cited, these fossils, referred 
to the Merostomata, have aroused great interest among geologists and 
paleontologists, principally for the reason that they come from beds con- 
sidered by Mr Walcott as Precambric (Greyson shales of the Belt terrane 
in Montana). Merostomata from beds so ancient would be of especial 
interest to the phylogeny not only of the eurypterids but also of all related 
subclasses, since it might be postulated that forms of such age were the 
common ancestors of the Merostomata and Arachnida, and perhaps also 
of the Crustacea. | 
Through the liberality of the secretary of the Smithsonian Institu- 
tion the authors have been able to investigate the principal types and a 
number of other selected specimens of Beltina. These specimens are in 
a dark fine grained somewhat micaceous shale which does not, in hand 
specimens at least, afford much evidence of shearing or distortion. The 
_“ Beltina’’ bodies lying parallel with the bedding of the rock are, it 
appears from the records, very abundant as the collections of the National 
Museum contain hundreds of specimens. They are flat films or smooth 
patches left by organic films, and these only in the rare instances which 
have been illustrated present suggestions of resemblance to known mero- 
stome organs. The fact of their very great age and their presumable 
primitive form as the possible ancestor of quite diverse classes of 
organisms should not too rigidly force our expectations of exact resem- 
blance but in such a multitude of fragments the occasional approach to the 
outline of an eurypterid limb, as for example to the free ramus of a 
Pterygotus chelicera [op. czt. pl. 25, fig. 13] must be looked upon as favor- 
