SPONGES, GRAPTOLITES, CORALS. 81 
Diplograptus.] 
i to 4; mm. in size, and are in direct contact throughout, no interstitial tissue of 
any kind being developed. The tubes are irregular in form, with thin, often undu- 
lated walls, which are not pierced by any apertures or pores, but are often crossed 
by more or fewer transverse partitions or “tabule.’ Very commonly the tubes 
exhibit more or fewer inwardly directed partitions, which extend to a greater or 
less distance into the cavity of the tube, and are the result of the cleavage or ‘ fission’ 
of the tubes.” 
Formation and locality—Rare in the Trenton shales near Cannon Falls, Minnesota; Frankfort, 
Kentucky and Nashville, Tennessee. In the Black River group at Pauquette Rapids on the Ottawa river, 
and island of Montreal, Canada. In division L, Newfoundland. Dr. Nicholson says it has also been 
found in Great Britain and Russia. 
Mus. Reg. No. 8055. 
Sub-Kingdom COREE NCH IR APA 
Class VY DROZOA.. 
Sub-class GRAPTOLITOIDEA. 
Family DIPLOGRAPTID Ai, Lapworth. 
DreLocraptus pristis? (Hisinger) Hall. 
1837. Prinotus pristis HISINGER. Letheea Suecica, p. 114, pl. 35, fig. 5. 
1847. Graptolithus pristis HALL. Paleontology of New York, vol. i, p. 265, pl. 72, figs. la—Is. 
1863. Graptolithus pristis BiLLInes. Geology of Canada, p. 200, fig. 195. 
1865. Graptolithus (Diplograptus) pristis HALL. Canadian Organic Remains, dec. ii, p. 15, fig. 3b: 
p. 109, figs. 21, 30. Fa 
1867. Graptolithus (Diplograptus) pristis HALL. Twentieth Rep. N. Y. State Cab. Nat. Hist., pp, 
182, 205, figs. 22, 32. 
1875. Diplograptus pristis NICHOLSON. Paleontology of the Province of Ontario, p. 38. 
Prof. Hall gives Hisinger’s description of this species as follows: “Linear, 
straight, scarcely a line broad, compressed; rachis central, capillary; both sides 
with broad acute teeth’ (op. cit. 1847). 
—6 
