286 S. WELLEK FAUNA OF THE FERN GLEN FORMATION 



the longitudinal ridges the most prominent and continued distally upon 

 the brachial plates as distinct radial ridges; first costal plates smaller 

 than the radials, crossed longitudinally by the strong, keel-like radial 

 ridge, and with much weaker raised ridges passing laterally to the first 

 interbraehial plates ; second costal plates axillary, the strong radial ridge 

 bifurcating at the center of the plate and the two distal divisions passing 

 to the distichal plates; normally there is a single axillary distichal plate 

 in each series, each of which supports, two palmer plates which are the 

 last brachial plates included in the calyx ; the distichal and palmer plates 

 are directed in a nearly horizontal direction, the interdistichal region in 

 each ray being deeply depressed, with an interdistichal plate between the 

 arm bases. Anal plate somewhat smaller than the radials ; above the anal 

 are two slightly nodose plates with raised radiating ridges passing to the 

 adjoining plates; these two plates are followed by three nearly smooth 

 plates, and these by others between the arm bases. First interradial plate 

 of each area nodose, with raised, rounded, radiating ridges passing to each 

 of the adjacent plates; these plates support two plates distally which are 

 smooth and flat or with only faint radiating ridges. Ventral disk conical 

 to the base of the anal tube, with the sides nearly straight; moderately 

 depressed to the interradial spaces between the arm bases, the small plates 

 flat or gently convex, the larger ones with low, broad, rounded nodes; 

 three plates arranged in a triangle above the arm bases of each ray are the 

 most conspicuously nodose. Base of the anal tube central. Arm open- 

 ings four in each ray. 



The dimensions of the type specimen are : Height to base of anal tube, 

 31.5 millimeters; height of dorsal cup, 16 millimeters; diameter at base of 

 arms, 32 millimeters. 



Remarks. — This species is established upon a single, slightly distorted 

 calyx, which is complete to the base of the anal tube. The specimen is 

 slightly abnormal in the right anterior ray, in which there is but a single 

 costal plate, but in this ray both the radial and the single costal are some- 

 what larger than are the corresponding plates in the other rays. 



PHYSETOCRINUS SM ALLEY 1 n. sp. 



Plate 11, figures 1-3 



Description. — Calyx wider than high, the ventral disk much higher 

 than the dorsal cup, the depressions between the rays narrow. Dorsal cup 

 broadly obconical to the top of the costal plates, beyond which the brachial 

 plates bend outward in a nearly horizontal direction ; costal plates strongly 

 aodose, the nodes of successive plates connected more or less completely 



