26 



niul aboiit tlio samo size. It is follnwcd hy three larjje plates, the 

 middle oiie of which is much elongated ami unites willi the y)latesof 

 the vault. 



Vault pyramidal liy reason of the de])ressed interradial areas, 

 nearly as large as the calyx, and bears a central proboscis. It is 

 covered by convex, polygonal plates. 



This species bears little or no resemblance to any other tifteen- 

 armcd species. When compared with B. riislirclliix above de- 

 scribed, it will bf seen that it bears sixteen arms and that neither 

 the azygous area nor any of tiie interradial ari-as connect with the 

 vault, while this s])ecies bears tifteen arms and all the areas are 

 widely connected with the vault. A close iuspection shows a differ- 

 ence in structure in nearly all respects. Like <lifferences will be 

 found when comxjared with other species. 



Found by the veteran collector. E. A. Blair, to whom science is so 

 nnich indebted for unremitting labor, in the liurliiiglon (inni)). nt>ar 

 Sharon, in the Southwestern i)art of Missouri, and- now in the col- 

 lection of S. A. Miller. 



K.VTOCIUNTS KOTII.IFORMTS, 11. sp. 



Phitc T, Fi(j. 2(>, hfisdl view m<i(/iiifie(l firo diumclcrf:: Fiij. .'7, s(i)itc 



tudiind size. Plate J I, Fifj. 1, (I'.iinoiis rieir : 



yiij. 2,sniiiiiiit rieir. 



Species below me<liuni size, liiturbinatc wlicd-slmped. Calyx 

 curving outward from the base to the arms, more than twice as wide 

 as high. No radial ridges, but the radial series are lobed and pro- 

 ject at the margin so as to notch the circumference at. the inter- 

 radial spaci>s. Plates convex and linely granular. .\iiibulacral 

 ojienings directed slightly above an horizontal line, not visible in a 

 basal view, but may be seen in a summit view. \o ovarian pores de- 

 fected, and probably they open through the first arm [ilale. 



Basals form a short hexagonal disc five times as wide as high, 

 notched at the sutures, and having an hemispherical depression 

 for the attachuient of the column. First i)rimary radials not as 

 large as the second and third together, about twice as wide as long, 

 three hexagonal and two lieptagonal. Second primary radials 

 ([uadrangular, from tlire(> to five times as wide as long. Third 

 primary radials about one half larger than the second, four hexa- 

 gonal, OIK! lieptagonal, axillary, and the ray oi^posite the azygous 



