xlvi TABLE OF GENERA. 
CAMBRIAN. SILURIAN. 







4 a r e 5 
a i=) 5 . : wm 
z ! a jes ee |e £ ees 
a . bel — Pa 3s 
q : cH = 3 ro) A 3 a am laal a 
3 ad | pies s a || = gS 5 5 ei ce 
So) SN Sal & ay | EM |) ee) aie | & | ea] & veel = 
| w & 4 3 m 2 Mu isa} H to) H mw 3 3 
| i) a) se) g e) i=} 5) 3 = re) 3) a 2 
See Wee Wee aleee a ies ae | Sahel |= 
P= a =f = =) =| | et | sels} HE | Sy iS We 4 
Heteropoda 
Bellerophon ... sae 500 
Maclurea Jas Bas oe 
Pteropoda 
Theca aa wee me 
Stenotheca ... = ae 
| Cyrtotheca... 500 ses 
Conularia nae ane ES. 
Eccyliomphalus 500 608 
Graptotheca ... Ss ae 
Cephalopoda 
Orthoceras... 28s ae 
Cyrtoceras a Es Mae 
Ormoceras ee Ane oe 
Lituites See see ade 
Phragmoceras - s0C 
| Trochoceras ... nae Ac 
Tretoceras ace ane is 
Pisces 
Onchus ake 00 Ses 

Pteraspis Ae ah ac 

