560 
CLINTON R. STAUFFER 
Horizon and locality.—Amherstburg dolomite, Stony Island 
Dry Cut, Livingston Channel, Detroit River, near Trenton, 
Michigan. 
DESCRIPTION OF PLATES 
All figures are natural size. 
Mr. G. S. Barkentin, delineator. 
Figs. 
Figs. 
Fig. 
Figs. 
Fig. 
Figs. 
Figs. 
4 
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zl 
Som w win H bd 
Sy Tel el) 
PLATE I 
. Arachnocrinus zgnotus n.sp. 
. Dorsal (?) view. 
. Poterioceras canadensis n.sp. 
. Ventral view. 
. Dorsal view. 
. Lateral view. 
. Posterior view of the last chamber preserved and showing posi- 
tion of siphuncle. 
PLATE II 
. Rhipidomella intermedia n.sp. 
. Brachial valve. 
. Pedicle valve of same specimen. 
. Schizophoria prima n.sp. 
. Pedicle valve. 
. Stropheodonta delicatula n.sp. 
Impression of brachial valve showing impression of part of 
cardinal area of pedicle valve. 
. Impression of brachial valve of another specimen. 
. Nucleospira livingstonensis n.sp. 
. Pedicle valve. 
. Loxonema inculta n.sp. 
. A small specimen showing surface markings fairly well pre- 
served. 
. A large specimen showing surface poorly. 
PLATE III 
. Callonema perlata n.sp. 
. Lateral view showing character of surface markings. 
. Apical view. 
