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IOWA ACADEMY OF SCIENCE 



Vol. XXVI, 1919 



crescentic in section "and bearing on the horns of the crescents two 

 longitudinal rows of strong cirri. "^ These cirri embraced the crown 

 and the inner coils and afforded still further protection to the vital 

 parts of the animal. The nearly circular segments next to the crown 

 do not bear cirri. It is obvious that the concave side of the stem 

 is found on the inside of the coils and that when closely enrolled 



Fig. 121. — An illustration of a specimen of Salter's genus Herpetocrinus 

 from the Niagaran dolomitic limestone near Monticello, Iowa. Total length 83 

 millimeters; greatest diameter across the coil, 20.6 millimeters, shortest, 16.0 

 millimeters. Length of the distal missing part of the stem unknown. Magnifica- 

 tion a little more than four and one-half times. 



the concave side fitted more or less snugly over the convex side of 

 the next coil within. 



The fossils from Monticello are highly silicified. The cirri are 

 lost but the cirrus-articulations are plainly visible on several of the 

 segments of the accompanying illustrated specimen as well as on the 

 Henley specimen. In the better specimen the calyx is present and 

 even the arms are represented by a series of ill-defined ossicles which 



'Zittel-Eastman, Textbook of Paleontology, 2nd Ed., p. 212, 1913. 



