48 o NORTH AMERICAN INDEX FOSSILS. 



^lississippic. 



5. T. woodmani Meek and Worthen. (Fig. 1790.) 

 Radials long and narrow. (Type of genus.) 

 Warsaw of Indiana. 



6. T. obliquatus (Roemer). 

 Radials elongate-oblong. 



St. Louis of Tennessee, Indiana; Warsaw of Illii 



Mississippic. 



Fig. 1790. Triccelocrinus woodmani. A complete calyx, with basal and summit 

 views, nat. size, and anal portion enlarged, X 2. (After Etheridge and Carpenter.) 



V. Pentremitidea d'Orbigny. 

 Shape of calyx varying from slender and elongate to club- 

 shaped, and to Pentreinites-like. Base more or less long and con- 

 ical. Number and general arrangement of plates as in Pentremites 

 but ambulacra narrow. Lancet plates more or 

 less concealed by the side plates, and deltoids 

 usually invisible. Devonic. 



7. P. filosa Whiteaves. (Fig. 1791.) 



Devonic. 

 Greatest diameter of calyx ranging from 

 ViG. 1791. Pentre- slightly below the middle of the calyx to the 

 base of the ambulacra. 



Hamilton of Ontario and Michigan. 



8. P. americana Barris. Devonic. 



Small, pyriform; height twice the greatest diameter, which is 

 a little below the middle; form conical at base, but pentalobate 

 above ; radials two thirds the length of the calyx, the forks occupy 

 two thirds the length of the plates, are narrow and end in sharp 

 points. Readily distinguished from the preceding by its greater 

 length of base, and more conical aspect of lower half. 



Hamilton (Traverse) of Michigan. 



niitidea filosay^2. (Af- 

 ter Whiteaves.) 



