The Electlre Sf/sfen). — U'adstrnrf/K 223 
nus amer/'caiiHs, Pleirrofomaric im'/tiina, Gonialites louisianen- 
sis, Amhocoplia ni/'inifa. C'/jrfiiKi acatirostrix, Orthothetes lens, 
Chonetes (letiiciilafa, ('. oniafa, Spirifera mar /'one it sis, Spiri- 
ferina aeiculifern, ProdncteUa pi/ridafd, N ifcleosjiiro harrisi. 
and other well known Kinderhook species. 
Explanation of Figures. 
Figure 1. Diagram illustrating the arrangement of plates in the body 
and arms of Aristocrinns, a new genus of erinoids. 
Figure 2. Azygous view of the type specimen of Aristocriniis concavus 
(Rowley); natvu-al size. 
Figures 3 and 4. Lateral and venti-al views of the largest specimen of 
Allagecriuus aniericaims, sp. nov., greatly magnified. 
Figures 5 and 6. Similar views of a medium sized specimen of the .same 
species, highly magnified. 
Figures 7 and 8. Side views of smaller specimens' of the same species, 
greatly enlarged. 
Figure 9. Ventral view of a large .specimen of the same species, greatly 
magnified. 
Figure 10. Lateral view of a medium sized specimen of the same spe- 
cies, greatly enlarged. 
Figures 11 to 13. Lateral, ventral and dorsal views of the type specimen 
of Granntocriniis iSchhMblastns?) m(((/iiib((sis, .sp. nov., natural 
size. 
Figure 14. Lateral view of a large distorted specimen of the same spe- 
cies, natural size. 
Figure 15. Lateral view of the largest specimen of GoniatUes louisia- 
nensis, sp. nov., natural size. 
Figures 1G to 18. Lateral, dorsal and ventral views of the same speci- 
men, enlarged. 
Figure 19. A greatly magnified view of the type specimen of Pleiiroto- 
maria minima, sp. nov. 
Figure 20. Miircliisonia ? pjfijma'a, sp. nov. Type specimen, greatly 
magnified. 
THE ELECTIVE SYSTEM AS ADOPTED IN THE 
MICHIGAN MINING SCHOOL. 
By M. E. Wadsworth, Din-ctor. Houfflitoii, MicliiKaii, 
In this country two systems have been chiefly followed in 
the higher educational institutions, — the fixed and the elect- 
ive. The latter was introduced first in this country by Pres- 
ident Wayhind, of Brown University, and it has since been 
systematized and developed with remarkable skill and success 
by President Eliot, of Harvard. Indeed, the system has 
proved to be so well adapted to the needs of modern times 
and to be so popular that it has made its way in the face of 
