GRAPTOLITES. 55 
TABLE SHOWING THE VERTICAL DISTRIBUTION OF THE GENERA OF THE FAMILY OF 
GRAPTOLITIDE. 
R) 
2 
oO o0| ap 
4 5 ale 
oS 2|\2 : 
man ae oa 
oI 8 \o |S al epl.© 
BIE Idlgl/slalsia=imisis|s 
Si So tas] Hig ~lislid 
ols Ble S g/2 SS } a eI g [o) 
naloNSlg N).5 = 6o| 2 o ie) 
ia & © |S | ).8 aio E ei vile 
OSA Hl S| OS |slo a) s/o) 
BIOOIB (DS lO le Ol4 |p lq |O|o 
ah eee Sub-genus Monoprion .......-[..| x |a|sl.-|x a ' 
RAPTOLITHUS, 9 Sub-genus Diplograptus...-../..| x |x| iC ve 
GIIMAGOGRARTUS*scceiete dscns coe plelc tenes SSSR Shale lise salle. RE a 
I evAHEA GU RINPNUTS Seoteretctetaroteteleltiei che: eletiorer si ciecereyausye creultorerl MSee ithe Mine lle: cillesesfeveilfaveillecallarsiiis ail eyaclre 
FUENEEONTMMSe eaeretat leveled sieiotets sels ete sivtuigerensreree secratonott Sets WD a Ve wilese Ivele alee Meiiace loetiee 
AERC) CAMELS tetalalefale) sustelelale) ate ele)leiricrsiare/e =)s/e) sfelsiel|ieve | 5 i 
DENDROGRAPTUS .-.+-sees med apetelcate eta n ave rataxtes cues eral Spe See Pavel le ces d fore aes fay l tee Pare fares easel ails 
QATTOERAPINUR) 4oHo coo OUdd DUDDDOOOU DOUDIAO DC nial lmcon isla| ees or pele 
IDiOT WON. jn cagoopon bouoT Good oDdonddoEoodS Bila? # 
PTH OELAPTUTEL A ocac bo domoooodanonod Goddocdallnalyce 
EPAWENOG HAUT US) s\alsabel elieleba le siniele)oiaele/ aia =| e's/elele) ee live | SC. Illa 01|/5% 
Schoo) Sale| sales |B 
RASTRITES ...+.0. Rast teletatardital settee Secee a aes Bocabitect He 
IDROHABTRESS God pOb a0 CODD DOO COBO OC COUCIOCIOOIGG nai lacie areal aa 
ESUIBENGAIE LS tateveatel are falc’ shereleveletoleevan's evsie eveie elise ae at ae illo s 
QD nAITIN ? sions pacino COU MON O Gite Cite OCECCR COE RCI ieaen (-teymn ioal ope 
The pre-eminence of the Quebec group, as the period of the greatest 
development in the Graptolitidee, is shown in the above table. Of the 
fifteen genera and one sub-genus here enumerated, eleven are known in 
this period ; while four genera, viz., Phyllograptus, Dendrograptus, Callo- 
graptus, and Ptilograptus, are not at present known in any higher position 
than the Quebec group, though one of them occurs in the Potsdam Sand- 
stone. All those genera having the nearest relations with Graptolithus 
proper occur in this group, and the species of that genus found in it are 
more numerous than in all the subsequent formations, so far as at present 
known. 
In addition to circumstances originally favorable to their development 
and growth, the subsequent conditions presented during the period of the 
Quebec group in Canada seem to have been equally favorable to the 
preservation of graptolites, and in no other formation have they been 
found with all their parts so entire. 
* Under this genus, in the following table I have introduced a sub-genus, Dicrano- 
graptus. 
