Lysimachia ciliata, L.. 
31 
Lysimachia nummularia, L_ 
33 
Lythrum alatum, Pursh 
32, 33 
Medicago 
29 
Melilotus alba, Lam 
34 
Menispermum Canadense, L. 
30 
Mimulus ringens, L 
3i 
Nesaea verticillata, H. B. K. 
31 
Oenothera fructicosa,. L 
31 
Passiflora lutea. L 
34 
Penthorum sedoides, L 
32 
Phryma leptostachya, L 
31 
Ptelea trifoliata. L 
29 
Ptero-carya Caucasica, KenelL 
30 
Robina Pseudacacia, L 
30 
Rubus 
30 
Ruella ciliosa, Pursh 
31 
Sambucus Canadensis. L 
30 
Scrophularia nodosa, L 
31 
Sisymbrium officinale, Scop. 
31 
Solanaceae 
29, 34 
Teucrium Canadense, E 
31 
Thalictrum dioicum, L 28, 
3L 34 
Trifolium 
34 
Ulmus fulva, Michx 
35 
Verbena stricta, Vent _ 
31 
Verbena urticifolia, L 
31 
Vitaceae 
34 
Pleochroism 
134 
Pleuroxus procurvus 
37 
Ploesoma lenticulare 
57 
Polyarthraea 
48 
Polyarthra platyptera 
49 
Pterodina patina 
59 
mine: 
Q. 
QUARRIES. — 
Allen’s 
74 
Carrollton Pike 
70 
Centreville 
74 
Day' on 
73 
Eaton Pike 
66, 70 
Fair Flaven 
75 
Fauver’s 
75 
Huffman’s 
73 
Soldiers’ Home 
70 
Stolz’s 
67 
Swartzbaugh’s 
68 
R. 
Rattulus 
49 
Rock sections 
121 
Rotifers of America . 
43^ 62 
Rotifer . : 
47 
s. 
Salpina affinis 
52 
Salpina mucronata 
52 
Scardium . 
49 
Squamella bractea 
54 
Stephanops muticus 
54 
T. 
Table of abbreviations 
137 
Tables for determination of 
rock-forming minerals_ 
^37-157 
Thoulets’ method 
123 
Triarthra 
48 
Twinning phenomena 
133 
u. 
Use of polarizing microscope- 
131 
LS. 
A. 
Acmite XV 
Actinolite XV 
Afftrre^ates XIX 
Albite XVII 
Alamandine garnet II 
Analcite III 
Anatase V 
Numbers refer to cable. 
Apatite VIII 
Aragonite 
Augite XIV 
Andalnsite XI 
Andesite XVII 
Anomite XII 
Anorthite XVIII 
Anthophyllite X 
B. 
Basite X 
Biotite VIII 
Bronzite X 
Bytownite XVIII 
C. 
Calcite VII 
Cancrinite VII 
