SYSTEMATIC INDEX. 











PAGE 



PAGE 



HISTORICAL INTRODUCTION 



i 



Tetragraptus, Groups of ... ... 56 



INTRODUCTION 



1 



— quadribrachiatus 







.. 57 



DESCRIPTION OF GENERA AN 



D 



— crucifer ... 







58 



SPECIES 



5 



— Headi 







.. 59 



Family Dichograptidse 



5 



— Amii 







.. 60 



Didymograptus 



5 



— fruticosus 







61 



- Groups of 



7 



— pendens ... 







.. 63 



extensus ... 



8 



— Postlethwaitii ... 







64 



- nitidus ... 



10 



— serra 







.. 65 



— uniformis 



12 



— reclinatus 







67 



- patulus ... 



.. 13 



— Bigsbyi ... 







.. 68 



hirundo ... 



.. 15 



— Table of Species of 







70 



— sparsus 



17 



Scliizograptus 







.. 70 



pennatulus 



.. 18 



— reticulatus 







71 



- superstes 



.. 19 



— tardifurcatus 







72 



- euodus 



.. 21 



Trochograptus 







.. 73 



affinis 



.. 23 



— diffusus ... 







.. 73 



- gracilis ... 



.. 24 



Holograptus ... 







.. 74 



acutidens 



25 



— Deairi 







.. 75 



- Nicholsoni 



.. 27 



Dichograptus ... 







76 



- — var. planus ... 



29 



— Groups of 







77 



- serratulus 



.. 29 



— octobracbiatus . . . 







77 



— simulans... 



.. 30 



— — var. Sedgwickii 







.. 79 



- filif ormis 



.. 32 



— separatus 







80 



- v.-fractus 



.. 33 



Loganograptus 







.. 80 



— var. volucer ... 



.. 35 



— ■ Logani ... 







.-. 81 



- deflexus ... 



.. 35 



Clonograptus ... 







82 



Murchisoni 



.. 37 



— tenellus ... 







.. 83 



— var. geminus 



.. 40 



var. Callavei... 







84 



— bifidus 



42 



Temnograptus 







.. 85 



— amplus ... 



44 



— multiplex 







.. 86 



- indeutus ... 



.. 45 



Bryograptus ... 







.. 87 



- nanus 



47 



— Groups of 







.. 87 



— art us 



.. 48 



— Kjerulfi ... 







88 



— stabilis ... 



.. 49 



— — var. cumbrensis 







.. 89 



— fasciculatus 



.. 50 



— divergens 







.. 90 



— gibberulus 



.. 52 



Trichograptus 







90 



Tetragraptus . . . 



.. 55 



— fragilis ... 







... 91 



