80. CONTRIBUTION TO 



This flattening and tendency toward angular ambulacral ridgts is an ap- 

 proach to jV. Aiigalarin. Outside of this the separation of the species is very 

 great. 



Fig. 12, plate 26, is an anal side view of another elongate specimen with 

 flattened areas as in Fig. 11. This specimen shows the spiracles and anal open- 

 ing free from foreign matter. 



Fig. 13, plate 26, is drawn to show the unusually large size of the speci- 

 men. It is a veritable giant. The ambulacrum on the right is covered nearly 

 half its length below b}' the adjacent edge of the interradiai plate, due perhaps 

 to pressure, as the specimen is not symmetrical, being flattened somewhat lat- 

 erally, and shorter on one side ihan on the other. 



Figs. 14 and 15, plate 26, are summit and side views of a handsome 

 small specimen of the elongate type. The anal ])late on this is quite promi- 

 nent, and all the interradiai plates, as well as the anal, are somewhat sulcate. 

 The ventral roof of small plates is present and the spiracles are exposed. 



Hidden in the small basal cavity of this Specimen is the top stem joint aa 

 in figure 21. 



Fig. 18, plate 26, is a finely preserved, elongate specimen, but somewhat 

 mutilated on one side. The interambulacral fields are convex except near the 

 top and the base, where they become a little sulcate. The ambulacra are of" 

 medium width and a little above the general surface. The anal plate is above- 

 the surface only near the top. The radials are about one-seventh the length of 

 the body. The cross and longitudinal surface lines show well on the specimen. 



Fig. 19, plate 26, is a side view of a slightly elongate specimen, showing; 

 rather strf)ng ornamentation. The interambulacral areas are full, giving to a 

 cross section an almost perfectly circular outline. The basal cavity is clean in 

 this specimen, and the ventral covering in perfect condition, the little plates- 

 having a granular surface appearance. 



Fig. 20, plate 26, is a side view of an elongate specimen with the inter- 

 ambulacral areas hardly convex, presenting much the appearance of figures 11 

 and 12. Only the top of the anal plate is above the general surface, and the 

 base and summit present the usual appearances seen on well preserved specimens. 



Fig. 21, plate 26. is a basal view of an imperfect, elongate specimen. The 

 upper stem joint, with its round central perforation, occupies the center of the- 

 basal concavity. In this specimen the anal plate is not only sulcate, but above 

 the general surface for over half its length. 



Fig. 22, plate 26, is a side view of a smpll elongate specimen of almost 

 circular cross section, the ambulacra being a little above the general surface^ 

 and the anal plate even more pronounced than in figure 21. 



