149 
PALEONTOLOGY OF NEW-YORK. 
Arms composed at base of two thick plates, succeeded by about four 
wedgeform plates ; and above this an alternating series of interlocking- 
plates, which are furnished on their outer margins with jointed ten- 
tacula. Tentacula undetermined. 
Column large, consisting of alternating thicker and thinner joints. 
This beautiful species is figured and described from a mould in sandstone, and 
from detached plates and fragments of columns. It belongs to the type having simple 
arms like M. plumosus and M. spinulosus , and is the finest species of the group. 
There is some obscurity in structure about the bases of the arms, but the representa¬ 
tion is essentially correct. Each third radial supports two first brachial plates, and 
these each in turn two others, from which originate the simple arms; giving twenty 
arms, as in the other species of this group. The portions of the arms remaining are 
more than three times as long as the body, and probably they were originally at 
least four times as long as the body. 
Fig. 1. The specimen, natural size, preserving the body, and on one side a part of the arms 
and a portion of the column. 
Fig. 1 a. Diagram illustrating the structure from the base to the lower part of the arms (for 
comparison with structure of Mariacrinus pachydactylus and M. plumosus, plate 
iii). 
Fig. 2 & 3. Fragments of columns apparently of this species. 
Fig. 4. Section of column fig. 3. 
Geological position and locality. In the Oriskany sandstone : Cumberland, Md. 
Mariacriims (Subgenus) Teclinocrmiis striatus (n.s.). 
Plate LXXXYI. Fig. 12 & 5 - 11. 
Body unknown. Surface of plates marked by strong elevated striae, di¬ 
verging from the centre. Basal plates four, wider than long, small. First 
radial plates wider than high. 
Column small. 
This species is founded on the base and first radial plates, and numerous separated 
plates of the same character. The surface markings are not unlike those of Techno- 
crinus andrewsi , but are finer, the column and base proportionally much smaller, 
and the first radial plates proportionally shorter. 
Fig. 12. The basal plates anchylosed together with a small portion of the column attached, 
and also one first radial plate. 
Fig. 5, 6, 7, 9, 10 & 11. Several plates of different series belonging to this species. 
Geological position and locality. In the Oriskany sandstone : Cumberland, Md. 
