PLATE XII. 



C '< u> as 1 1: u PYKAMIDATTJSj Shiuiiuril, p. 2(>f>. 



''• ' 

 Fig. 1. Summit view of a moderately well preserved specimen, showing the interradial 



ridges, ambulacra; hydrospire-slits, mouth, and anus. Comiferoua Limestone, 



Kentucky. x 4 88 



Fig. 2. Radial view of the same specimen. x 3 30 



Fig. 3. Anal interradius of the same. x 3 16 



N.B. — The radio-deltoid sutures ai'c rather too distinct, both in these and in the next 

 figure. 



CODASTER IllNDEI, E. fy C. 



Fig. 4. Summit view, showing the same characters as Fig. 1. Hamilton Group, Ontario. 



Coll. Hinde. x G 32 



Fig. 5. lladial view* of the same specimen. x -1 30 



Fig. 6. Aual interradius of the same. x 4 2G4 



Fig. 7. Portion of an ambulacrum, somewhat worn. x 30 61 



CODASTER TRILOBATUS, McCoy , p. 2G8. 



Fig. 8. Section of the calyx from above, showing the eight groups of hydrospires and their 



abseuce from the anal interradius. Carboniferous Limestone, Lancashire. x 4 32 



Orophocrixus verus, Cumberland, sp., p. 290. 

 Kg, 9. Section of the calyx from above, showing the deep spiracular clefts and the canals 

 within the lancet-plates, one of which is continued onwards to the peristome 

 between two deltoid plates. Carboniferous Limestone, Lancashire. x G . 97 



PHyENOSCHISMA ArCHIACI, E. 8f C, p. 274. 



Fig. 10. Interradial view of a specimen which has the top stem-joint preserved, and a curved 



interbasal suture. Lower Devonian, Asturias. x 2 20 



Troostocrixus Reinwardti, Troost, sp., p. 194. 



Fig. 11. Radial view of the calyx. Niagara Group, Tennessee. x2 36 



Fig. 12. Terminal portion of a radial sinus, exhibiting the side plates above, underneath 



them the lancet-plate, and below the latter the tops of the hydrospires. x 4 . 93 



Pextremites pyriformis, Say, p. 167. 



Fig. 13. The proximal end of a radial sinus, showing in the middle line the under lancet- 

 plate, on each side the tops of the hydrospires, and above it the ambulaeral 

 opening between two deltoids. Subcarboniferous. Coll. Ilinde. xG. . . 51 



Fig. 14. Inner view of the portion of the lancet-plate which fits into the sinus shown in 



Fig. 13. On the left, at the bottom are visible the backs of five side plates. x 6 34 



Fig. 15. Section of the calyx from above. The water-vascular ring is seen in the centre, 

 with its five branches into the lancet-plates, and between the latter the groups 

 of hydrospires. Coll. Hinde. x 5 101 



