LOWER HELDERBERG ROCKS. 139 



Fig. 1. The right side of an individual, showing the arrangement of plates, pectinated 

 rhombs, etc. 



Fig. 2. The anterior side, showing the pectinated rhombs at the base. 

 Fig. 3. The posterior side, showing the ovarian aperture with the surrounding plates removed. 

 Fig. 4. The left side of the same specimen. The prominence of the ovarian side over the 

 opposite is well seen in fig. 1 & 4. 



Fig. 5. A smaller individual with the column entire and the body mutilated. The base of 

 the column is quite solid, showing no evidence of rings. 



Fig. 6. Another individual preserving the column and plates of the body, the latter some- 

 what crushed. The articulations are partially visible in the base of the column, 

 which condition is in a measure due to wearing of the surface. 



Fig. 7. A small specimen showing the pectinated rhombs and structure of the body on the 

 right side. The column is nearly entire, showing the articulations from base to 

 summit with almost equal distinctness. The fingers are converged together above 

 the summit of the body, giving it a pointed appearance. 



Fig. 8. The body somewhat broken, but preserving the fingers or pinnules to the length of 

 three-fourths of an inch. 



Fig. 10. The summit of a specimen much crushed, but preserving a portion of the arms and 

 fingcrg. 



Fig. 11. A single plate of the second range enlarged, showing the character of surface, the 

 pectinated rhomb, etc. 



Fig. 12. Enlargement of a portion of a plate, showing surface markings. 



Fig. 13. Enlargement of a part of an arm, with the fingers folded down upon the body of 

 the fossil. 



Fig. 14, 15, 16. Bases of several columns, the two first showing slight evidences of rings, 

 while the other appears quite solid. 



Fig. 17, 18. Enlargements of the surfaces of the solid bases of columns. 



Fig. 19. Transverse section at the top of the solid portion, showing the central canal and 

 the rings within the exterior wall. 



Fig. 20, 21, 22. Lateral and sectional views and enlargement of a fragment of a large 

 column, which exhibits characters very similar to the base of Lepadocrinus. 



Geological position and locality. In the Pentamerus limestone of the Lower 

 Helderberg group : Helderberg mountains, Schoharie, Cherryvalley, Cedarville, 

 Jerusalem hill, and many other places in New- York; and Cumberland, Maryland. 



[ PALiEONTOLOaT IIL] 17 



