Ul-yich on Ccrrelaticn cf the Lower Silurian. 
183 
research may show to be less restricted in their range than 
given. 
First, however, it is necessary to state that I divide the series 
into four j^rincipal divisions, which in part agree with those 
adopted by both the Ohio and Kentucky geologists. They are 
based upon recognizable though not sharply distinguished lith- 
ological peculiarities, and upon more pronounced faunal differ- 
ences. The lower two divisions are each again subdivided into 
two minor sections, distinguished as a and 6. All of these divis- 
ions will be considered in detail later on. 
Table of the prixcipat, fossils of Beds XI, XII, XIII 
AND XIV, SHOWING THEIR DISTRIBUTION AND RANGE. 
1 Buthotrephis gi-acilis Hall 
2 " ramulosa S. A. Miller 
.3 " flexuosa Hall 
4 Palaeophycns rugosum Hall 
5 •' ? virgatus Hall 
6 Licrophyeus flabelhim Miller and Dyer . 
7 Dactylophycus tridigitatum M. and D.. 
8 Heliophycus stellitorme M. and D 
9 Lockeia siliqiiaria Janiet* 
10 Rusophycus bilobatum Hali 
11 " pudicum Hall 
12 Cyclophycns laterale Ulrich Ms 
13 Sphenophyllum primaevum Lesq 
14 Calathinrn sp 
15 Discophycus typlcalis Walcott 
16 Dystaetospongia insoleus Miller 
17 Patersonia diiticilis Miller 
18 Heterspongia subramosa Ulrich 
19 Strom atocerium pustulosum Safford.... 
20 Beatrieea nodulosa Billings 
21 " undulata Billings 
22 Labechia ohioensis N"icb(jlson 
2.'} " niontifera Uliich 
24 Girvanella richmondensis Miller 
25 Solenopora compacta Billings 
26 Palaeophyllum divaricans Nicholson.... 
27 Zaphrentis canadensis Billings 
28jColurnnaria alveolata Goldfuss 
29 Columnaria halli Nicholson 
30| " caiicina Nicholson 
31|Columnopora cribriforniis Xich 
32 ~ ' ■■ 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
Protorea vetnsta '.'Hall. 
Tetradium api)roxiniatum I'lrich 
" fibratum Saffoi'd 
Graptolithus gracilis Hall 
" tennis? Portlock 
Dendrograptus gi-aeillimus Lesq 
" tenuiramosns, Walcott. 
Dicranograptus ramosus Hall 
Diplograptns whitfieldi Hall 
" spinulosns Hall 
Climacograptus typicalis Hall 
2 2' 
1 
* 
* 
* 
b 1 a 
* * 
ft 
* 
* 
* 
* 
te I ta 
