LOWER HELDERBERG GROUP. 133 



Arms unknown. 



CoLUiiN deeply inserted into the body, composed of large joints above, 

 becominjc smaller below. 



^o 



Anomalocystites coinutus (n. s.). 



Plate VII A. Fig. 5 - 7. 



Body subovoid, longitudinally concavo-convex. Concave side showing two 

 basal plates and a part of two basi-angular plates, one large subcentral 

 plate with two lateral' plates, one irregular one on the upper lefthand 

 angle of the large central plate, and a terminal range of small plates. 

 Convex side showing three basal plates ; the central one hexagonal, 

 succeeded by five series of small plates. 



Tentaccla or spines, two or more. 



Proboscis ? 



Column composed of large circular joints at the junction with the body, 

 and becoming rapidly smaller and pentagonal below. 



All the specimens of this species which have been seen are crushed, and more or 

 less distorted and imbedded in stone. The form and structure has been more fuily 

 understood by comparison with a free specimen of another species from the Oriskany 

 sandstone of Maryland. A single specimen shows a column of an inch in length. 

 The structure in five different individuals corresponds with that represented upon 

 the plate. In one individual there is a projecting spine or tentacle from each side, 

 apparently joining the angles at the summit of the convex side : there may have 

 been more upon the other parts of the summit. A central node or proboscis 1 is seen 

 in the same specimen. 



The plates appear to be marked by transverse subimbricating lamellae and fine 



granulate surfaces. No pores, ambulacra, or other openings are visible. 



Fig. 5. The convex side of an individual witli a portion of tiie column attached. 



Fig. 6. The concave side, showing the two arching basal plates, the large central plate, and 

 the gaperior range of plates. 



Fig. 7. A plate enlarged, showing the lamellar structure. 



Fig. 7 a. Diagram illustrating the structure of the body, and the relative position of the 

 plates on the two sides. 



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

 Helderberg group : Jerusalem hill, Litchfield, Herkimer county. 



