2/6 TJie American Geologist. NoTcmber. i899 
as Antedon now does. At least Asteroidea were represented 
then in Minnesota, as is shown by very rare finds. 
Plate XII . 
Y\g. I. An isolated anterior radial. 
Fig. 2. Portion of figure i enlarged to show one of tbie rhomb 
areas. 
Fig. 3. Another radial plate. 
Fig. 4. Interior of a radial plate. 
Figs. 5 and 6. Interior and exterior of one of the supposed posterior 
radial plates. 
Figs. 7 and 8, The other posterior radial. 
Fig. Q. The anterior basal plate. 
Fig. 10. An infrabasal with pair of perforations at the lower angle 
within scar of stem. 
Fig. II. The unec^ual infrabasal. 
Fig. 12. Diagram of the anterior basal of the type specimen. 
Fig. 13 Diagram of anterior infrabasal. 
Fig. 14. Sketch of root showing stump of the stem. 
Fig. 15. Diagram of suture lines on surface of the last, X 5. 
Fig. 16. Corroded root. The one limb of the specimen curves 
under the supporting pebble. 
Fig. 17. A much reduced remnant of a root, X %.. 
Fig. 18. Carabocrinus, posterior side of calyx, after W. Billings as 
published by Wachsmuth and Springer in "Crinoidea Camarata," vol. 1, 
figure 2. 
NOTES ON THE CORUNDUM-BEARING ROCKS OF 
EASTERN ONTARIO, CANADA. 
By WiLLET G. MiLi>EE, Kiugstoii, Ontario, Cauada. 
( Plate XIII.) 
The writer spent the summers of 1897 and 1898 in a study 
of the economic geology of part of eastern Ontario for the pro- 
vincial Bureau of Mines. On beginning the work, he was 
asked to make an examination of the corundum deposit, the 
occurrence of which had been reported by Mr. W. F. Fer- 
rier, iithologist of the Canadian geological survey, in the 
autumn of 1896. 
By the time field work was begun, in 1897, another deposit 
had been discovered. The mineral was found to occur under 
similar conditions in the two deposits, it being an original 
constituent of syenyte, syenyte-pegmatite and nepheline sye- 
nvte. 
