NIAGAHA GEOUP. 231 



Fig. 6 a, b, c. Columns composed of smooth equal joints, having lateral branches or side arms. 

 The articulating surfaces are marked by numerous fine dichotomous striae, reaching 

 to the round central canal. These columns are remarkable for their external smooth- 

 ness and equality of the joints, and for having been furnished with lateral appendages 

 at irregular intervals. 



Fig. 7 a. Pi. fragment of the base of a column where it diverges into the radicles : it is remarka- 

 ble for the strong strias upon the articulating surfaces. 



Fig. 7 b, c. The articulating surface, natural size and enlarged, showing the strong somewhat 

 dichotomous strite. 



Fig. 8. A fragment of a column with the radicles attached : at this point the column is composed 

 of three or four thin joints articulating with a single thicker one, all of equal dia- 

 meter, and the column having a smooth exterior. 



Fig. 9 a, h, c. The base of another species, with the radicles attached. The few joints remaining 

 are thin; the striae of the articulating surface are numerous and undulating, some, 

 times partially dichotomous, and appearing as if granulated. The characters of this 

 fragment are very similar to those of LecanocHnus ornaius, and it is probably the radix 

 of one of that species. 



Position and locality. These fragments, with the exception of fig. S, are from the shale at 

 Lockport. The specimen fig. 8 is from the lower part of the limestone at the same place. 



PLATE XLV. Figs. 3, 4, 5, 6, 10 and 11. 



Fig. 3 a, 6. A fragment of a small column, composed of unequal joints with rounded edges, 

 having scattered spines upon the edges of the thicker joints. The articulating sur- 

 faces are strongly striated, the strife reaching to the small canal in the centre. 



Fig. 3 c, d. Enlargements of the same, showing the form of joints, and the stris upon the articu- 

 lating surface. 



Fig. 4 a, b, c, d. A fragment similar to the preceding, having the spines more numerous and 

 proportionally longer, while the articulating surfaces are concave at one end and 

 convex at the other. 



Fig. 5 a, b, c. A fragment of a column, having the joints composed in part of thin irregular plates 

 not continuous on the margins. 



Fig. 6 a, b, c. A fragment of a compressed column, having two distinct centres, though appear- 

 ing as one externall)-. It is composed of alternating joints of equal thickness, but 

 of unequal width. The articulating surfaces are finely striated, the strije reaching to 

 a large solid oval space which may have been a canal. 



Fig 10 a, b. A fragment of a root, with numerous radicles, of an undetermined species ; with 

 a section of the same, showing a large irregularly triangular canal. 



Fig 11 a b A fragment of a root, with few radicles; and a section of the same, showing a 

 hexagonal canal. 



