52 FIELD CoLuMBIAN MuseEumM—GEo.oey, VoL. III. 
sphere. This number is of a very convenient magnitude, varying 
from 1 to 16.4 for the forms in the collections. This modulus is the 
reciprocal of the coefficient of rotundity. 
TABLE OF SPECIFIC GRAVITY AND Moputus oF ROTUNDITY OF CLAY- 
STONES. 
No. 8.G. M.R. Locality. . ones a 
‘Tt ($2779 ‘17. Osu Riga ay ermon 41-1 
Be py yaks \ 39-1 
ery erate 4 66—2 
Mees A eer : 39-2 
Sens iasul i Ns “~41—3 
ORE ee 4 72-3 
nay Aaa LO LO . 72-1 
§ Magn $8 og 69 
Gi nore ei 60s3 ie 72-2 
LOLA yi eet s 39-3 
Lifie 2:06) aes. . 37-3 
125 2.08 gie7.0 4 38-1 
Lgtiny2t Ogee Sear Thani eee 37-4 
£4 PhO 7 F220 ia 69-4 
Suhre xGtO 0m e.0 ve 40-1 
tive raelsns ae ey, ¥ | 40-2 
Le 200 Waael vg 5 69-2 
Torneo Steger A A 38-2 
COs Oa, rs | 40-2 
20m 92.041. MeL. E 69-3 
OI p62 0.8 Suet i 39-2 
2.4 OB WeameO % 37-I 
22. 9.97 4 wees Connecticut haven , 805-6 
SATE wt A 2 805-8 
Devise 3 en kA O yf 76-2 
2 w 27 Tw if 452-2 
eho Re ae 1.8 ‘c 805-7 
Behe Osho 3 70-2 
NT hag Komi We) it ; 70-1 
eer: CAS eer Ow bal a 55-2 
3 TOROS ot a0 ‘ 75-1 
22 ae OG se aeO ie - 805-2 
X36 DOG ules 7 805-4. 
SA sO0e antes 805-5 
