[MATTHEW] CAMBRIAN FAUNAS 103 
LINGULELLA. 
The Lingulellas of these lower Cambrian Zones are none of them 
typical, that is they have not the “satchel shape” form characterizing 
the type of the genus, L. Davisii, of the Upper Cambrian. Those 
that are treated of here belong to a phylum of oval forms which are 
found at intervals throughout the Cambrian system. The Lingu- 
lepides just cited are perhaps nearer Lingulella-typical, than the species 
named below. 
VALVES OF OVAL LINGULELLZ OF THE ETCHEMIN TERRANE, SHOWING 
INCREASE IN SIZE FROM THEIR FIRST APPEARANCE ONWARD. 



a By ns 
~ 2} os 
Assise NAME ci D ne 3 
o ra & 
À es pny < 
Co: Lingulella cf. longovalis ............... 74 5 1:50 37°50 
E. 1c Di eer ERP longovalis.:- 2." 8 5 1:60 40° 
Hee DÉMARRER longovalis wesley 9 6 1°50 54 
Increase of the latest beyond the first.|........|........|........ 1°5 

The increase in area is only one-half above the first integer; but 
then the range in time was short, viz.: Coldbrook and one-half of 
the Lower Etchemin Fauna. 
OBOLUS. 
Here is a complex group in which several phyla are involved: 
SIZE OF VALVES OF THE OBOLI AS THE SPECIES SUCCEED EACH OTHER IN THE 
ETCHEMIN TERRANE. 





2 a Be 
Assise NAME = 3 ye § 
© fre à + Le 
4 Bewley < 
Co: Obolirstorrenbiss yj sissies 6 5 "83 30° 
E. 1b OF tripariliste sees ssc 9 8 88 72° 
E. le Oe. GISCUSMe Eee sacha: 94 9 *85 85°5 
E. 2 (a?) OM: 57. RAMIDUbELS oc omnuoude Eee 12 11 92 132 
HS) Didier ONE SET RS SO En 14 12 86 168 
E. 3 4 OUT Bretonensis Pete 15 17 1:13 255° 
Increase of the latest beyond the first.|........|........|........ 8.5 
or 4.4 


In this series there are at least two phyla. The interior of 
O. torrentis is unknown, but the next three are characterized by the 
equality and regular arrangement of the central scars of the dorsal 
valve (including the anterior laterals), and by the possession of a small 
sear in the middle of this group of muscles.. The first phylum may 
