292 R. R. GURLEV 
with its three genera and more than 100 good species. In 
America only one genus and two species are known, one of them 
from Arctic America. One reason for this absence is undoubt- 
edly the predominance of limestone and the scarcity of shale in 
most of our Upper Silurian formations, but it cannot but be sus- 
pected that future collections may yield some of that wealth of 
forms to which European graptolithologists have long had 
access. 
CAMBRIAN. 
Lower | Middle Upper 
5 
St. John (N. B.) i 
S  |Group (Div. 3.)2 Canadai4 ic 
es s 
GENUS AND SPECIES - is ae 2 & 
ie a ec _o ND a 
Se) Be} S& a & a e.0 | -% 
ns ars ees ES Be) 2 
Ve OS NO eee sae ee ce4 | es 
Be | ss dag | Se | pee! 3 
fe | Be Sia | 56 | S85) B 
© < e=7 | G6 | Seo) 5 
Phyllograptus mee eae ee ae ? 
PicamibnenSiSmemcit cee W 
FAMOUS Sooogacooocods = — — 
LeMbUS Eis ie ene ern ee M3 | | 
MUI tiTGamMOosuUSuase eee | G 
PALES: or dvavern wiceneneuea se M | M3 | 
P IKSOTOMIERGUISE 5 coca coav0s M3 
FOUN ssce5560'occe or . M | M3 | 
SPeisana dees eeimeygess L 
Clonograptus ............. IL 
Dichograpsus) anaes: <= 
PLOXMIMIA CUS woe M3 
Staurograpsus ............ I | 
Climacograptus ........... ? | 
2 GWMINOMSI 5 goo nec 4000 56 Ww 
IPROOV ANAS ooo ce0e0 00ds == 
ATACUS Mee haescerasenen Mean M 
DWendrographusheene eee ? = 
hallliamusee erie eee 1 
PapLIMoxdialishee eres M | 
Calllograptusmeremnt rere = | 
SP Geaueteps ies ore icmp eee M3 
IDI ONS, Gaccacccou ones =| _— — —_— 
MA OSWIMONINE 6.500 oa G00 M3} M3 IG Ib, 
acadicuminne eee ane M;M,|M 
confertum (Lnrs J/S.)?. M 
nonvesicum):semeneers MM 
Oldhamia (like O. radiata). . | L 
Olenidac ees ae L 
