32 Trans. Acad. Sci. of St. Louis. 



reichen nur zur halben Hohe, wiilirend die luterradialstiicke 

 ungewohnlich gross sind. Granatocrinus norwoodi Owen 

 und Shumard. Kohlenkalk. Hierher gehoren aucli die 

 Pentremites JElUptici Roemer's." 



Granatocrinus norwoodi is taken as the type, but, in this 

 species, the deltoid-interradial is very small, and the main 

 peculiarity, i. e., the perforation of the deltoid, is not 

 mentioned. 



Nicholson and Lydekker, Manual of Palaeontology, Vol. 

 I., p. 464, define the genus thus: — 



" Granatoblastidae. Calyx globular or ovoidal with a 

 flattened or concave base and linear ambulacra. Spiracles 

 five, piercing the deltoids; or ten grooving their lateral edges. 

 This family includes the genera Granatocrinus and Hetero- 

 blasfus." 



This arrangement shows a marked inconsistenc}^ because 

 Heterohlastus possesses more essentially the characters of 

 Cryptoblastus, and has more aflnnities with it than with Grana- 

 tocrinus, so that it would more properly belong to this genus. 



Eastman's* definition is the following: — 



"Calyx globular or ovoidal with flattened or concave base 

 and long linear ambulacra. Spiracles five piercing the deltoids, 

 or ten grooving their lateral edges. Consisting of Granato- 

 crinus and Ileteroblastus.'" 



Here we have the same inconsistency. The last genus 

 has all the essential characters of Cr}/2)toblastus, with the 

 exception of spine-like processes on the deltoids, though 

 these spine-like projections are met with in many species, 

 for example Pentremites sidcatus, where it seems the 

 deltoid pieces are very much inclined to develop spiny 

 projections. I have a number of specimens showing them 

 of various forms and sizes. Those from the neighbor- 

 hood of Ste. Genevieve show it most, whereas those from 

 Chester or Evansville rarely show any such hypertrophic 

 growth, while we meet with it again in specimens from 

 Baldwin and other localities. 



Another case which shows very clearly the arbitrary way 



* Text-Book of Palaeontology, Vol. I., p. 196. 



