150 TRANSACTIONS OF THE [mMaR. 17, 
COMPARISONS AND CONCLUSIONS. 
In conclusion a few of the salient features which separate this 
fauna from all others, may be briefly given. 
All the trilobites have continuous eyelobes.* This is decidedly 
a primitive character, and its value in this respect can be shown 
from the genus Paradoxides, which began with small species 
having such eyelobes, and culminated in the large forms in which 
the eyelobe at maturity, was considerably shortened. This 
shortening up of the eyelobe was carried still further in the 
Oleni, dwarfed forms of similar type in the Upper Cambrian ; 
in these the eyelobe comes almost opposite the front of the gla- 
bella. : 
The important family of the Ptychoparida is absent. This 
family did not have continuous eyelobes, for in the young when 
this protecting fold first shows itself, it is short, and at the 
lateral margin of the head-shield. No trilobite with such an 
eyelobe has been found in this fauna. The Ptychoparida had 
about a dozen species in the Olenellus Fauna and became quite 
common in that with Paradoxides, continuing to abound through- 
out the Cambrian Age. 
The genus Conocoryphe is absent. This is specially a type of 
the Lower Paradoxides beds, and under the name of Cono- 
coryphe trilineata (Atops trilineatus) is claimed as a character- 
istic fossil of the Olenellus Zone.+ 
The genus Microdiscus is absent. This trilobite is specially 
characteristic of the Olenellus Zone, and continued to live with 
Paradoxides. In New Brunswick it occurs in the Paradoxides 
Zone, but not with Protolenus. In Europe it is only known to 
have lived with Paradoxides. 
The genus Olenellus is absent. Though carefully looked for, 
* That is, eyelobes that extend from near the front of the glabella to the posterior 
marginal furrow. 
+ This however, is probably an error, for the genus Conocoryphe is characteristic 
of the Paradoxides Fauna, and eminently of the Lower Paradoxides beds. It is found 
in this relation in Scandinavia, where, including Ctenocephalus, which has a similar 
range, no less than six species occur, all in the Lower Paradoxides beds; and four in 
Wales. In Bohemia also the genus occurs in the same connection, as also.in the north 
of Spain and south of France. In New Brunswick it is equally characteristic of the 
same horizon, as may be seen by reference to the author’s list showing the range of 
Cambrian species in this country (Trans. Roy. Soe. Can., vol. xi., pt. iv., p. 118); and al- 
though the species Conocoryphe trilineata has not been found here, the author has 
met with it in a collection of fossils from the Paradoxides beds of Manual Brook, New- 
foundland, sent to him by Mr. J. P. Howley. It is altogether probable that the Para- 
doxides Fauna is present in the slates of Washington county,N.Y., where Alops trilin- 
eatus occurs, but has not been recognized. The author several years ago drew atten- 
tion to the place of this genus in the chronological succession of the Cambrian genera 
in Trans.Roy.Soc.Can., vol. iv., pt. iv., p. 149. Olenellus asaphoides and Conocoryphe 
(Atops) trilineatus, which Emmons proclaimed as the characteristic fossils of his 
Taconic System, are types, the one of the Olenellus Zone and the other of the Para- 
doxides Zone, and sustain Emmons’ contention that his Taconic rocks were below the 
Potsdam sandstone. 
