20 NEW YORK STATE MUSEUM 
there was only one large and typical eurypterid fauna, that of the Bertie 
waterlime, known from the rocks of this State, and except the small 
fauna of the waterlime of Kokomo, from the entire continent. Of so 
much greater interest therefore is the discovery within a few years of three 
new and larger faunas. The first is that of the Pittsford shale at the base 
of the Salina beds in Monroe county, found by Clifton Sarle. Its most 
striking and common member is the representative of a new genus, termed 
by its discoverer Hughmilleria. This is a form which has a very interest- 
ing bearing on the phylogeny of Pterygotus and Slimonia. The eurypterid 
portion of the remarkable arthropod fauna of Pittsford has been elabor- 
ately described and figured by Mr Sarle in the Report of the State Paleon- 
tologist for 1902. It consists of the following species: 
Hughmilleria socialis Pterygotus monroensis 
H. sucialis var. robusta Stylonurus (multispinosus C. & R.) 
Eurypterus pittsfordensis 
The associated forms (crustacean species of Ceratiocaris, Pseudoniscus, 
Emmelezoe, Bunodes, mostly described by Clarke), the peculiar lithologic 
surroundings of this fauna, and the fact that through this discovery the 
salt and gypsum-bearing Salina beds are now known ta be both under- 
lain and overlain by Eurypterus beds, all bear on the problem of the 
physical conditions under which these animals lived. 
A second discovery was made in 1906 by the junior author of this 
book in the shales of the Shawangunk grit formation of southeastern New 
York. A preliminary description of this fauna was published by the senior 
author in 1907 [N. Y. State Mus. Bul. 107]. It consists of one species of 
Eurypterus, one of Eusarcus, one of Dolichopterus, six of Stylonurus, 
one of Hughmilleria and one of Pterygotus. It has furnished a contri- 
bution to the organization of the eurypterids in a specimen of Stylonurus, 
retaining all four posterior legs of one side, in the light of which 
previous restorations of that genus are greatly modified. The most novel 
feature of the Shawangunk grit fauna, is the presence of larval stages of 
