31 



BATOCRINOS POLITUS. n. Sp. 



Fldte I, Ft;/. 33, basal view; Fig. 24, azygous side; Fig, 25, 



summit view. 



Species small, subglobose, vault not as large as the calyx, longi- 

 tudinally constricted, on the azygous side. Calyx saucer shaped. 

 Surface of the plates plane and smooth. 



Basals form an hexagonal disc, with slightly re-entering angles, 

 about twice as wide as the diameter of the column, and having 

 an hemispheiical depression for the insertion of the column. First 

 primary radials nearly as long as wide, three hexagonal, two heptag- 

 oual. Second primary radials quadrangular, about twice as wide 

 88 long. Third primary radials a little larger than the second, 

 pentagonal, axillary, and, iu three of the rays, support, on each 

 upper sloping side, two secondary radials, which gives to each of 

 these rays two arms. In the ray on the left of the azygous area, 

 the third primary radial bears upon the proximal side two sec- 

 ondary radials and upon the distal side a single secondary radial, 

 which is axillary and supports, on each upper side, a tertiary 

 radial, which arrangement gives to this ray three arms. In the 

 ray on the right of the azygous area, the third primary radial 

 supports, on the distal side, a secondary radial, which is axillary, 

 and bears upon each upper side a tertiary radial; and on the 

 proximal side two tertiary radials, the last one being axillary and 

 supporting, upon one upper side, an arm, and upon the other a 

 tertiary radial, which arrangement gives to this ray four arms. 

 There are, therefore, thirteen arms in this species. The arm 

 formula is 4+2+2+2+3. 



There is only a single plate in each regular interradial area, 

 and it is cut off from the vault by the secondary radials. In the 

 azygous area there are five plates. The first one is in line with 

 the first primary radials, longer and fully as large as either of 

 them. It is followed by thi-ee plates, in the second range, the 

 middle one of which is the smallest and much elongated. There 

 is one elongated plate in the third range that rests upon the plate 

 ou the left of the second range and separates the middle plate, 

 in the second range, from the secondary radials on the left, and 

 extends up between the secondary radials and unites with the 

 plates of the vault. 



