INVEETEBEATES. 287 



POTEKIOCBINUS TALBOTi, Worthen. 



PL XXX, Fig. 7. 



Poteriocrinns Talboti, WOETHEN, February, 1882. 



Bulletin No. 1, of the Illinois State Museum of Natural History, p. 17. 



Body very short, basin-shaped, base depressed, and the basals 

 hidden in the basal concavity. 



Subradials short, curving inward below to form by their lower 

 angles part of the basal depression. 



Eadials pantagonal, twice as wide as high, widest at their upper 

 margins, and truncated squarely across for the reception of the 

 brachial plates. 



On the anterior ray, there are six or seven brachials, all becoming 

 narrower upward so that the last is only about half as wide as the 

 first. The last one is an axillary plate, and supports two arms that 

 continue simple to their extremities. The other rays have but a 

 single brachial, which is as large or larger than the radials on which 

 they rest, pentagonal in form, and give support on their upper slop- 

 ing sides to the first division of the rays. On the left antero-lateral 

 ray the arms divide on the sixth plate, beyond which they appear 

 to be simple, which would give four arms to this ray. If the pos- 

 terior rays, which are concealed in the rock in our specimen, cor- 

 respond with the antero-lateral ray, it would give eighteen arms to 

 the entire animal. Anal area and column unknown. 



I take pleasure in dedicating this species to my esteemed friend, 

 Henry Talbot, Esq., of Waterloo, to whom I am indebted for many 

 acts of personal kindness, and for some interesting fossils. 



Position and locality: St. Louis limestone, Monroe county, 111. 



No. 2,470, Illinois State collection. 



POTEKIOCRINUS VALIDUS, Worthen. 



PI. XXVIII, Fig. 16. 



Poteriocrinus valldus, WOETHEN, February, 1882, 



Bulletin No. 1, of the Illinois State Museum of Natural History, p. 18. 



Body more than twice as wide as high, forming a low, shallow 

 cup. Basals small and concealed by the first columnar joints. 

 Subradials hexagonal on the anterior side, strongly protuberant in 

 the middle and depressed at the angles, giving a very rugged ap- 



