30 The American Geologist. January. 1905 
EXPLANATION OF PLATES II AND III. 
Unless otherwise stated, the figures are of the natural size. 
PLATE II.— ENDOCERATIDAE. 
Genus and Species undetermined. 
Fig. 1. Side view of the more perfect of the two silicified 
siphuncles from Paquettes rapids described on pages 23 and 24. 
Genus and Species undetermined. 
Figs. 2 and 2a. Two views of the siphuncle from the Don 
bricltyard, described on page 24. 
Both of these figures are slightlj^ reduced in size, the 
original being fully seven inches and a half in length, as stated in 
the text. 
Nanno primaevus. 
Figs. 3 and 3a. 3 lateral, and 3a peripheral view of the type 
and only known specimen of this species. 
PLATE III.— ENDOCERATIDAE. 
Nanno kingstonensis. 
Figs. 1, la, and lb; 1 inner, la lateral, and lb peripheral, view 
of the apical end of the siphuncle of a shell of this species. 
Figs. 2, 2a, and 2b. Corresponding views of the prolonged por- 
tion of the siphuncle of a small but different specimen. 
Fig. 3. Peripheral view of an unusually well preserved frag- 
ment of the prolonged portion of a siphuncle, showing the forward 
curvature of the septal rings. 
Fig. 4. Longitudinal section of the anterior end of the pro- 
longed portion of the siphuncle of a large specimen, showing the 
endosiphuncle opening anteriorly into a deep, funnel-shaped cavity 
or endocone. 
