15 
1 Costal plates smooth. 1 Sp. planus. 
2 Costal plates tuberculated. 2 Sp. tuberculatus. 
oo Alimentary canal petal shaped. 
§ Articulating surface of columnar joints radiated. 
+ Auxiliary side arms round. 
{ Auxiliary side arms placed irregular. 
1 Costal plates with angular rugged 
strie. : 3 Sp. rugosus. 
** Column pentangular. 
ooo Alimentary canal pentangular. 
§ Articulating surface of columnar joints radiated. 
+ Auxiliary side arms round. 
{ Auxiliary side arms placed irregular. 
1 Costal plates smooth. 4 Sp. quinqu angularis. 
B Pelvis formed of three plates. 
% Five costal and one intercostal plate resting on the pelvis. VII. Gen. AcTINocRINITES. 
b Column not enlarging near the summit. 
b Fingers formed of two series of joints. 
* Column round. 
o Alimentary canal round. 
§ Articulating surface of columnar joints ra- 
diated. 
+ Auxiliary side arms round. 
{ Auxiliary side arms irregular. 
1 Thirty fingers proceeding from five 
scapule. 1 Sp. triacontadactylus. 
2 More than thirty fingers proceeding - 
from five scapula. 2 Sp. polydactylus. 
€ Five intercostal plates, resting on the pelvis, in whose 
lateral angles five costal ones insert. VIII. Gen. RnovocrinitEs. 
b Column. not enlarging near the summit. 
b Fingers formed of two series of joints. 
* Column round. 
oo Alimentary canal petal shaped. 
§ Articulating surface of columnar joints radiated. 
+ Auxiliary side arms round. 
{ Auxiliary side arms irregular. 1 Sp. verus. 
D Costal, or intercostal plates wanting the five scapule, 
adhering to the pelvis. V. Gen. PLatycRINiTESs. 
b Column not enlarging near the summit. 
b Fingers formed of two series of joints. 
