202 NEW YORK STATE MUSEUM 
markings like those of E. pustulosus but that “the shape of the 
carapace and the position of the eyes are so totally different that the 
two species can be distinguished very readily.’’ As a matter of fact, the 
proportions of the carapace and the positions of the eyes are quite the 
same in both specimens [see under Measurements]. 
In the same publication Pohl- 
man added several ‘‘new species”’ of * 
Pterygotus to those before described 
from the Buffalo waterlimes by Grote 
& Pitt, increasing the number to a 
half dozen, all of which are synonyms 
of P butialoensis  save-one: 
This latter was described by Pohlman 
as Pap lobe aiid bins. elt ts 
based on a single postabdomen, in 
relief and counterpart, now in the 
Museum of the Buffalo Society. The 
two were combined in one figure, 
here copied [text fig. 4o]. This 
figure illustrates the three principal 
characters of the specimen, viz, the 
bladelike extensions of the postlateral 
angles of the segments, the apparent 
globosity of the “‘telson’’ which gave 
Figure 40 Copy of original figure of Ptery - 4 ‘ 
gotus globicaudatus Pohlman. the species its name and the coarsely 
(From Pohlman) 
pustulate sculpturing. 
This ‘telson ” [pl. 24, fig. 1] has, at first glance, the features ascribed 
to it by Pohlman. It appears to have a round outline; the upper and 
lower plates have separated and a thick mass of matrix les between them, 
suggesting the globose character attributed to it. But such a “‘telson”’ 
would have compelled this unfortunate creature to drag, like a member of 
_an old-time chain gang, a cannon ball after him all his life. This structure 
