Genus Archæospherina, Dawson.
A provisional genus, to include rounded solitary chambers, or globigerine assemblages of such chambers, with the cell-wall surrounding them tubulated as in Eozoon, or perhaps in some cases with simple pores like those of Rotalines. They may be distinct organisms, or gemmæ, or detached fragments of Eozoon. Some of them much resemble the bodies figured by Dr. Carpenter, as gemmæ or ova and primitive chambers of Orbitolites. They are very abundant on some of the strata surfaces of the limestones at Côte St. Pierre. Age Upper Laurentian.
I may add here the characters of Matthew's new genus, Archæozoon, as given by him:—
Genus Archæospherina, Matthew.
Skeleton composed of thin concentric laminæ convex upward, and having between them a granular layer filled with minute branching canals.
Archæospherina Acadiense, Matthew.
Habit of growth cylindrical in masses or groups, budding upward. The microscopic characters are thus given by Matthew[54]:—
"The structures appear to be allied more closely to Cryptozoon than to Eozoon. The microscopic structure is most easily recognised in the earthy (as distinguished from the calcareous) layers, and consists of minute branching canals. Under a one-inch objective the smaller canals have the appearance of minute threads, which run sometimes for a distance of two millimetres without branching. The larger canals branch more frequently and are more sinuous. The canals cross and anastomose with each other; they run chiefly at right angles to the axis of the fossil, and appear to branch most in going outward from the centre. More rarely they ascend from the earthy to the calcareous layer, branching upward."
[54] Bulletin No. ix., Nat. Hist. Soc of New Brunswick, 1890.
In limestone of the Upper Laurentian, near St. John, New Brunswick.