60 



the second range, in the azygous area, but there are three. He 

 described the fourteen-armed species and gave the localities where 

 it has been found in abundance; but, he said, "the number of 

 arm- openings, in the specimens under examination, varies from 

 fourteen to fifteen." He probably had some specimens of this 

 species, which he did not distinguish from B. verneuilianus. But 

 twenty specimens of that species are found in Missouri, Iowa and 

 Illinois to where one is found belonging to this species, and there 

 can be no doubt about which one he regarded as the type of his 

 species. 



Found in the Burlington Group, in Iowa, Missouri and Illinois, 

 and in all good collections from that Group. Three of the speci- 

 mens illustrated are in the collection of S. A. Miller and one in 

 the collection of A. Albers. 



BATOCR1NUS COGNATUS, n. sp. 



Plate IV, Fig. 18, azygous side, a three-armed ray on the right 

 and a four- armed ray on the left; Fig, 19, four-armed ray 

 on the right lateral side of same specimen; Fig. 20, four- 

 armed ray on the left of the azygous area in another 

 specimen; Fig. 21, a four -armed ray and three 

 plates in an interradial area. 



Species variable in size from small to medium; somewhat bitur- 

 binate, but varying in this respect. Calyx obconoiial, about one- 

 half wider than high. No radial ridges, but arms more or less 

 clustered at the margin. Ambulacral openings directed nearly 

 horizontally and an ovarian pore by the side of nearly every one 

 of them. 



Basals form a round cup about four times as wide as high; it 

 is slightly beveled to the column, which is about two-thirds the 

 diameter of the cup. First primary radials usually wider than long, 

 three hexagonal, two heptagonal. Second and third primary radials 

 together not larger than the first. Second primary radials quad- 

 rangular, two or two and a half times as wide as long. Third 

 primary radials about twice as large as the second, pentagonal in 

 such forms as are represented in Figures 18 and 19, but hexag- 

 onal, in part of the rays, in such forms as are represented by 

 figures 20 and 21, axillary, and in the ray opposite the azygous 

 area, supports, on each upper sloping side, two secondary radials, 

 which gives to this ray two arms. In the specimen represented 

 by Figures 18 and 19, in the ray on the left of the azygous area, 



