Paleontology of the Cincinnati Group. 



117 



Remarks. — The variety germanus does not seem to differ 

 enough to warrant separate description. Wachsmuth and 

 Springer believe the genus Pycnocrinus to be founded on a 

 young specimen, and state that the specimens " referred to 

 Pycnocrinus are so embryonic in their condition, that it would 

 be speculation for us to assert to what species they belong." 

 (Review of Palaeocrinoidea, Part 3, p. 103.) The fact that the 

 specimens do not seem to have been attached seems to point 

 to an embryonic or immature condition, like the Comatula 

 stage of the modern crinoids. 



Genus 6.— MARIACRINUS Hall, 1859. 



Calyx obconical, with the general aspect and ornamenta- 

 tion of Glyptocrinus ; radiating striae pass from plate to plate; 

 basals 4, small, of almost equal size, the one facing the anal 

 area largest; primary radials 3 X 5> nearly as wide as high, 

 increasing in size upwards; first set joining laterally; second 

 set inclosing the first anal and first interradial plates ; the 

 third set supporting 3 x 10 secondary radials, that are gener- 

 ally of uniform size, and vertically separated by 6 or more 

 interaxillary plates ; secondary radials followed by several 

 tertiary radials, that vary in number with the age of the in- 

 dividual, 5 or more at times, all placed in a direct line with 

 the arms, and somewhat resembling arm-plates; arms 20, 4 

 to each ray, inner ones branching once or twice, outer ones, 

 simple; both inner and outer arms composed of quadrangular 

 single joints, with straight or oblique sutures; arm bearing 

 joints subpentagonal ; main arms and branches fringed with 

 pinnules; interradial areas large, depressed, and composed 

 of a great number of plates, the first wedged in between the 

 upper sloping sides of two first radials and two second radi- 

 als ; second interradial series consisting of 2 plates, and each 

 succeeding series of 2 or 3 ; a?ial area wider, the first plate in 

 line with the first interradials, succeeded by three plates in 

 each succeeding series; vault composed of very minute, ir- 

 regular pieces without definite arrangement; anal aperture 

 eccentric, opening directly through the vault ; column (in our 

 species) 4-sided, each side slightly concave ; central canal 



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