1896. ] NEW YORK ACADEMY OF SCIENCES. 211 
front of the glabella and the side-lobes behind the rachis of the 
pygidium are divided by an indented line.”* 
This group, both in Sweden and eastern Canada, was one of the 
first to appear, and it proved also to be one of the most persist- 
ent. The following species and varieties may be referred to it : 
Agnostus obtusilobus. 
A Davidis, Hicks. 
A —— gibbus, Linrs. 
A —— var. partitus. 
A —— var. acutilobus. 
A —— Nathorsti, Brogg. and var. confluens, n. var. 
A fissus, Lundg., and var. trifissus, n. var. 
A punctuosus, Ang. 
Limbati. 'Tullberg divides this group into two sections, viz., 
Regii, of which A. rex, Barr, is the type, and Fallaces, with P. 
fallax, Linrs., as the type. Both sections are old, being found 
in the earliest Paradoxides beds both in Europe and America. 
This group (Limbati) has the following characters: “ A shield 
which is generally more quadrate in form than the Longifrontes; 
the head shield has a broader marginal fold; the basal lebes of 
the glabella are more prominent ; the cheeks in front of the gla- 
bella are not separated by a furrow, and they are smooth, and 
the pygidium commonly has a pair of spines at the back margin.” 
“The section Regii is distinguished by its broad marginal 
fold, by the reduced cheeks and reduced side lobes of the 
pygidium ; also the glabella, especially at the front part, is 
broad, and the third joint of the rachis of the pygidium is 
shortened.” 
The Regii have been found in America in the first and third 
sub-faunas of the Paradoxides zone. Only two species are 
known. 
Agnostus regulus, and 
A - Rex, Barr., var. transectus n. var. 
The section Fallaces has the following characters : “ The head 
shield is smaller, the marginal fold not so broad, the cheeks are 
larger, the basal lobes of the glabella rather large, and the third 
joint of the rachis of the pygidium is the largest.” 
The following species are found in eastern Canada and New- 
foundland : 
Agnostus fallax, Linrs., var. vir. 
 ——_ var. concinnus. 
jG var. trilobatus n. var. 
A, — Acadicus, Hartt. 
A var. declivis. 
* The last character is not constant as regards the pygidium.—G. F. M. 
