17 



Family EHODOCEINID^. 



ARCH^EOCRINUS PECULIARIS, n. sp. 



Plate IT, Fig. 1, lateral view of a specimen slightly compressed 

 laterally; Fig. 2, azygous view of same, showing the curved 

 radial series ivith an azygous plate over ihe first 

 radial; Fig. 3, basal view of same. 



Species large. Calyx globose ; greatest diameter about the top 

 of the second primary radials and very slightly exceeding the 

 height ; constricted below the arms ; plates convex and free from 

 radial ridges ; sutures beveled ; surface granular. 



Basals small, deep within the calyx and covered by the column. 

 Subradials longer than wide and truncated at the superior ends by 

 the first interradials. The inferior ends curve abruptly into the 

 columnar cavity and are notched so as to give a subpentagonal 

 outline to the columnar cavity, which indicates that the column 

 (which is unknown) is pentagonal. These plates curve gently up- 

 ward so that the calyx will rest below the middle and show half 

 the length in a side view. 



Four of the first primary radials are pentagonal, about equal in 

 size, and about as wide as high. The other one is hexagonal, has 

 unequal sides and is the largest plate in the calyx. It is on the 

 left of the azygous area and supports on its upper side an azygous 

 plate and upon the left superior lateral side the second primary 

 radial, as shown in the illustration. 



Four of the second primary radials are hexagonal, about the 

 same size as the four first primary radials and nearly as high as 

 wide. The other one is pentagonal, somewhat smaller and inclined 

 so as to present a horizontal upper face for the support of the 

 third primary radial, as shown in figure 2. 



Third primary radials very little more than half as large as the 

 second, smaller than the adjoining interradials, of about equal size, 

 about as wide as high, pentagonal, and support on each upper slop- 

 ing side a single secondary radial. Secondary radials a little more 

 than half as large as the third primary radials, hexagonal and sup- 

 port upon the inner upper sloping sides a secondary interradial, and 

 upon the superior faces a single tertiary radial, and upon the outer 

 upper sloping sides two tertiary radials (?). Our specimen is not 

 preserved beyond these plates. There are, therefore, twenty (?) 

 arms arising from the calyx. 



