86 
The follo'U’ing table shows the equivalent terms for the plates in the 
calyx of Tribmchioo'imts used hy the Authors who have written on the 
genus, including those now employed : — 
Table shoAving equivalent terms for the plates in the calyx of 
Trihrachiocrinus used hy different Authors. 
Plates. 
McCoy, 1847. 
De Koninck, 
1877. 
Eatte, 
1885-87. 
Wachsuiutli and 
Springer, 188G. 
Bather, 1890. 
Herein used, 
1892. 
1st Cycle. 
• 
Pelvis, or 
dorso-central 
plate. 
La base. 
Easals. 
Under-basals 
Infra-basals. 
Infra- 
basals. 
2nd Cycle. 
First costals. 
Sous-radiales 
Sub-radials. 
Basals 
Basals. 
Basals. 
3rd Cycle- 
' 
Interscapulars. 
Scapulae, or 
ray-bearing 
plates. 
Premieres 
pieces 
radiales. 
Pik'es inter- 
radiales. 
Eadials. 
Inter- 
rad ials. 
>- Radials. 
J 
Radials. 
Radials. 
V 
Intercostal. 
Pieces an ales 
(8.) 
Anals. 
Azygous 
plate. 
Radianal. 
Azygous 
plate. 
Second costal. 
Anal piece, 
or subquad- 
rangular 
anal plate. 
Bracliianal. 
Anal. 
Costals, or 
brachials. 
Costals. 
Brachials. 
Messrs. Waehsmuth and Springer describe the azygous plate in 
Trihrachiocrinus as subquadrangular, or trapezoidal in outline, and the anal 
as subquadrangular ; but in their diagramatic dissection^ of the calyx, the 
latter is figured as jientagonal, and such in reality is the form of both. By Sir 
P. M‘Coy the azygous plate, his intercostal, is correctly figured,^ but 
* Revision of the PaUeocrinoidea, 1885, Pt. Ill (1), t. 6, f. 5. 
* Anil. Mag. Nat. Hist. 1847, XX, t. 12, f. 2c. 
