19 



rays four arms. The tliinl |)riinarv radial on each side of tlie azygoiiS 

 area bears upon the distal side three secondary radials and upon the 

 proximal side two secondary radials, the last beino; axillary, and bear- 

 iui>- upon each upx)er slopinj:; side two tertiary radials. which gives to 

 each of these rays three arms. There are, therefore, sixteen arms in 

 this species. The arm formula is 3-r4+2-i-4-}-3. 



There are two plates in each regular interradial area, the first one 

 is nearly as large as a first primary radial, and the second one is quite 

 small and cut ofl' from the vault l)y the union of two secondary radials, 

 or two tertiary radials, in each adjacent ray. In the azygous area 

 there are seven plates. The first one is in line with the first primary 

 radials and as large as either of them. It is followed by three rather 

 large plates, in the second range, and above these upon the right side 

 and superior part of the middle one there are tw^o plates, one of w'hicli 

 is followed by a small plate that sei^arates the tertiary radials and 

 unites with the plates of the \ault. 



The vault is unsymmetrical. It is most tumid above the four armed 

 rays and somewhat longitutlinally depressed on the azygous side. 

 The ])lates are convex, and there is a large subcentral proboscis. 



The shape of the vault reminds one of the vault in BdiacriniiK 

 j>i/i-(iiiii(lalns. but the two species are so widely separated, in all the 

 material parts of the structure, that no comparison is necessary. In 

 structure it comes nearer Batofriiiiitt cognafiis than to any other 

 species, though the arm formidas are different and there are more 

 secondary and tertiary radials in this species than in that one. In 

 general appearance there is very little resemblance between the two 

 species. 



Found by R. A. Blair, in the Burlington Grouj), near Sharon, in 

 the southwestern part of ]Missouri, and now in the collection of 

 S. A. Miller. 



BATOClMNrS SCITUM'S n. Sp. 



I'litir I. F'kj. 10. ((-.iiijdiis niilc: Fi)/. II. diiiHisilc ricir. 



Species medium size, biturliinaie. Calyx obconoidal. about one- 

 fourth wider than high. No radial ridsres. Plates very slightly con- 

 vex except the lirst primary radials and first azygous plate, each of 

 which bears a central node. Amiiulacral openings directed a little 

 above a horizontal line. No ovarian pores discovered. 



