51 



BAT0CRIN08 SAGETOWNENSIS, n. Sp. 



Plate 1 V, Fig. 5, azygous side: Fig. 6, opposite view; Fig. 7, 



summit. 



Species large, aomewhat urn-shaped. Calyx somewhat obco- 

 noidal, nearly as long as wide, broadly truncated, constricted above 

 the basals, lobed in the superior radial regions. Plates convex, 

 the larger ones nodose. Ambulacral openings directed upwards 

 and not visible in a basal view. 



Basal plates the largest in the body, and form a cup about 

 twice as wide as high and about twice as wide as the diameter of 

 the column. They extend below the end of the column and are 

 constricted iu the upper part First primary radials large, longer 

 than wide, three hexagonal, two heptagonal, and each one bears a 

 transverse central node. Second primary radials t^uadrangular, 

 about one-half wider than long. Third primary radials a liille 

 larger than the second, pentagonal, axillary, and support, on eacii 

 upper sloping side, two large, secondary radials, the last being 

 axillary and supporting, on each upper sloping side, a single, large 

 tertiary radial, which arrangement gives to each ray four ambulacral 

 openings to the vault. There are, therefore, twenty ambulacral 

 openings to the vault in this species. 



All of the interradial areas connect with the plates of the vault. 

 The regular interradial areas are elongated, of uneqal size, and 

 contracted toward the superior part. The first plate iu each of 

 the areas is large and nodose. In one area there are two plates 

 in the second range, one in the third range, and one in the fourth 

 range, which unites with a single plate belonging to the vault. In 

 another area there are two elongated plates, in the second range, 

 that unite with two elongated plates, that curve over upon the 

 vault. In another area there are two plates, iu the second rauge, 

 that unite with two plates, in the third range, that unite with iwo 

 plates belonging to the vault. The other area has the same num 

 ber of plates that are iu the first area, above descrilied, antl they 

 are arranged in nearly the same order, dut ditl'er in size. Tlieie 

 are eleven f)lates in the azygous area. The first one is in line 

 with the first primary radials, and of about the same size and 

 ei^ually as nodose. It is followed by three plates, sube([ual in 

 size, in the second range. In the third rauge there are four 

 plates, one of which is quite small and (quadrangular, and abovt? 

 it and in line with the upper part of the largest plate, iu the 



