29 



BATOCKINUS LEVIGATUS, n. Sp. 



Flcite I, Fig. 21, azygous side; Fig. 22, opposite view. 



Species variable iu size, from below medium to large. We have 

 specimens less than half the size of the one illustrated. Vault 

 smaller than the calyx. Calyx obconoidal and the larger specimens 

 depressed, in the interradial areas, so as to give it a somewhat 

 obpyramidal outline. It expands quite regularly from the column 

 to the arms. Ambulacral orifices directed above an horizontal line 

 and not visible in a basal view. Surface of the plates plane and 

 smooth, some of those on the vault, sometimes, slightly convex. 



Basals form an hexagonal disc about one-half wider than the 

 diameter of the column, and bearing an hemispherical depression 

 for its attachment. First primary radials wider than long, three 

 hexagonal, two heptagonal. Second primary radials quadrangular, 

 two or three times as wide as long. Third primary radials a little 

 larger than the second, pentagonal, axillary, and, in the ray oppo- 

 site the azygous area, bear upon each upper sloping side four 

 secondary radials, which gives to this ray two arms. In the ray 

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

 upon each upper sloping side two secondary radials, the last being 

 axillary, and supporting on the distal sides three tertiary radials, 

 and ou the proximal sides two tertiary radials, which arrangement 

 gives to this ray four arms. In the ray ou the left of the azygous 

 area (we speak of the right and left sides of a specimen as seen 

 in the illustrations, without reference to the anterior and posterior 

 sides), the distal side bears three secondary radials, the last being 

 axillary, and supporting on each upper side two tertiary radials; 

 and the proximal side bears two secondary radials, the last being 

 axillary, and supporting on each upper sloping side three tertiary 

 radials, which arrangement gives to this ray four arms. In the 

 right lateral ray, the third primary radial- bears upon each superior 

 sloping side three secondary radials, the last ones being axillary, 

 and one of them supporting upon each upper side two tertiary 

 radials, and the other one supporting upon each upper side three 

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

 In the left lateral ray, the third primary radial bears upon one 

 upper sloping side three secondary radials, and, upon the other, 

 two secondary radials, the last ones being axillary, and supporting 

 on each upper side two tertiary radials, which gives to this ray 



