100 Natural History Society of N. Bulletin No. lY. 
serve as coiiiiectiiig links to bind these several sub-faunas together as 
one connected whole. 
Before describing tlie three assemblages of organic forms that 
are found in the lower part of the St. John Grouj:), it may be well to 
give a brief statement of the nature and order of the beds in which 
they occur. Tlie St. John Group has been divided into six princij^al 
masses of strata, designated as Divisions 0, 1, 2, 3, 4 and 5. Of 
Division or Series 0 it may be said that no organic remains have 
been found in it ; but in Division 1 is found the fauna described by 
Professor Hartt and others. This fauna is not found at the base of 
Division or Series 1, but in one of the middle members. Series 1 at 
St. John has been described as consisting of four bands of strata, 
differing in the nature of the sediments, and designated respectively 
in ascending order as «, c and d. The band a is a barren group, 
and c contains the species already described ; but both h and d are 
now found to have each its own peculiar assemblage of species. 
The oldest fauna is found in the band h. It is littoral, and its 
deep-sea equivalent is not known, but its crustaceans differ from 
those of the next band. The connecting link between the fauna of 
this band and that of tlie band c above it, is found chiefly in the 
brachiopods and pteropods. In the fauna of h are two new and remark- 
able types of bivalve crustaceans. The solitary trilobite known, 
Agraulos (?) is notable for the great development of the axial lobe 
of the cephalic shield and thorax, and of the close approximation of 
the eyes to the glabella. In this feature it resembles Conocoryplie 
Lyelli of the Welsh Cambrian strata. Two species of the pteropods 
display the remarkable feature, in this class, of a camerated shell, 
and were apparently adapted to resist the accidents of life on a 
sandy sea sliore. As for the brachiopods, we find among them only 
the most primitive types — Linnarssonia, Lingulella, Acrothele and 
Acrotreta. 
On passing to the beds of band c a flood of new forms present 
themselves, among which are two types of sponges, Protospongia (?) 
and an undescribed genus. The Cystidian, Eocystites, also appears 
at this horizon. To the genera of brachiopods referred to as found 
in band l> are now added three species of the genus Orthis, and another 
Lingulella takes the place of that found in band h. Among the 
gasteropods are several genera Stenotheca (?), Scenella, Harttia, etc. 
The pteropods are well represented in Hyalithoid species of three 
