178 Canadian Record of Science. 
as Pterinea and Modiolopsis represented. Pterinea insueta, 
Conrad, young individuals or a variety of the type species, 
also Modiolopsis modiolaris, Conrad, occur in tolerable 
abundance, but Lyrodesma pulchellum, Emmons, may be 
said to be the commonest and most characteristic of this 
class in the Utica terrane. 
Of the brachiopoda—Leptaena sericea, Sowerby, Orthis 
testudinaria, Dalman, and Strophomena alternata, Conrad, are 
found in the lower Utica shales almost everywhere; but 
one of the most characteristic forms of this interesting class 
is the minute, though abundant, Leptobolus insignis of Hall. 
Billings had observed its presence in the Montmorenci 
section and referred to it as a small Discina. On a small 
slab—the size of one’s hand—there may be counted some- 
times as many as twelve individuals—all in a tolerably 
good state of preservation—and presenting the characters 
of the genus remarkably well At Murray Bay, Lake St. 
John, Montmorency—around Quebec, at Montreal, Ottawa, 
Gloucester, Whitby, Collingwood, ete., this form occurs in 
almost every collection made and serves as a very good in- 
dicator of the presence of the Utica. Small individuals of 
Zygospira modesta, Say, are also very characteristic and in- 
timately associated with the previously mentioned species. 
The Utica representatives of this species are rather diminu- 
tive, some individuals being scarvely more than one or two 
millimetres in length, and indicate or present the protegulum 
very markedly in such nepionic forms as we find especially 
about Ottawa. . 
Amongst the most interesting of the brachiopoda how- 
ever, Siphonotreta Scotica, Davidson, marks a very interest- 
ing horizon. One single individual of this species, alone, was 
found by the writer amongst the numerous collections of 
brachiopoda gathered together by the late Mr. Billings. 
To Mr. J. W. H. Watts, of the Ottawa Field Naturalists’ 
Club, and to Mr. Whiteaves is due the honour of discovering 
and making known this beautifully ornamented and setate 
tretenterate brachiopod. In a paper prepared by the writer 
and read in the winter of 1887, entitled: ‘‘ Notes on and the 
