8 
MUSEUM BULLETIN NO. 3. 
127 
Endoceras 
proteiforme 
128 
Litoceras 
hercules 
129 
Orthoceras 
formosum 
130 
O. 
lyelli 
131 
O. 
magmsulcatum 
132 
O. 
seiboldi 
133 
O. 
n. sp. 
134 
Poterioceras 
apertum 
135 
P. 
obesum 
136 
Spyroceras 
bilineatum 
137 
S. 
feruro 
138 
Aparchites 
minutissimus 
139 
Beyricbia 
parallela 
140 
Bollia 
semilunata 
141 
Bythocypris 
cylindrica 
142 
B. 
lindstroemi 
143 
B. 
obtusa 
144 
Ctenobolbina hammelli 
145 
Krausella 
anticostiensis 
146 Primitia lativa 
147 Primitiella canadensis 
148 Schmid tella sublenticularis 
149 Tetradella lunatifera 
150 T. simplex 
151 Ulrichia nodosa 
152 Brachyaspis alacer 
153 B. altilis 
154 Bumastes orbicaudatus 
155 Calymmene callicephala 
156 Ceraurus pleurexanthe- 
mus 
157 Ceraurinus icarus 
158 Chasmops n. sp. 
159 Isotellus gigas 
160 I. cf. maximus 
161 Proetus alaricus 
162 Ischyrina winchelli 
Ordovician System , Gamachian Series . 
Ellis Bay Formation . On the north shore the sandy shales 
of the Charleton formation give place without stratigraphic 
break to the basal Ellis Bay sands; but on the south shore the 
sequence is continued with limestones and shales, the latter 
becoming more important near the middle. The formation 
is excellently and extensively exposed in Ellis bay on the south 
shore and Prinstie bay on the north. On the south side the 
thickness is 180 feet, but in the northern outcrops it greatly ex- 
ceeds this figure. 
This formation is placed in a series distinct from the Rich- 
mond, the ground being taken that it is younger than any division 
assigned to that series. On the other hand it is considered 
older than any North American formation referred to the Sil- 
urian. The great number of Richmond species which continue 
into this formation and the total absence of any evidence for 
a break of any kind are considered good reasons for its retension in 
the Ordovician. It is to be noticed, however, that twenty-four 
of the twenty-six species of Charleton bryozoa become extinct 
with that formation and that of the twenty-two species of Ellis 
Bay bryozoa, twenty species are introduced with the Ellis Bay 
formation. Furthermore, the Ellis Bay bryozoa have their 
closest affinities with Silurian faunas, although fifteen of the 
species become extinct within the formation. 
