ipo The Ottawa Naturalist. | August 



Dorsal cup rather widely spreading upwards with concavo- 

 convex curve ; plates with axial folds ; RR projecting markedly 

 to the facet. Height of cup (197 mm.) 100; width at base, 48 ; 

 width at summit, 132. Plates, especially IBB and RR, wider 

 than high. Arm-facet .28 of R. x, which is very wide, supports 

 3 (or more ?) tube-plates. Proximal columnal quinquelobate ; 

 IBB project beyond it. 



Upper Wenlockian, Niagara shales of Waldron, Ind. 



Four cotypes in American Museum of Natural History, No. 

 1897. These are said to be figured hy Hall, Rep. N. Y. State 

 Mus. Nat. Hist. XXVIII, pi. xv, ff. 10-17. But Hall there mentions 

 five specimens. Which of them is missing ? 



Since Dr. Stuart VVeller has confirmed the reference of this 

 species to Botryoerinns, it is unnecessary to argue the point. His 

 description is but slightly modified from Hall's and is presumably 

 based on the co-types, or at any rate on topotypes. But when he 

 says that the somewhat rare specimens found in the dolomite of 

 Bridgeport near Chicago "are indistinguishable from typical indi- 

 viduals from Waldron' , it must be objected that his figure (pi. 

 xiv, f. 12) by no means bears out this statement. The plates in 

 this specimen are a little disarranged, and possibly have lest some 

 of their outer form by solution ; but it is easy enough to see the 

 following points of difference. The dorsal cup shows no sign of 

 spreading upwards, but seems to have had straight sides. The 

 absence of axial folds may possibly be due to solution ; but it is 

 clear that the radials do not project towards the facet, which con- 

 sequently has not the markedly oblique slope seen in the cotypes. 

 Approximate proportions, based on the figure, are : height, 100 ; 

 width at base, 45 ; width at summit, at most, 123. The plates 

 are perhaps wider than high, but not nearly so much so as in the 

 cotypes. The arm-facet, which appears shallow, and far from 

 "indenting the plate to about one-fourth of its depth", is drawn 

 as at least .46 the width of the radial, x does not appear at all 

 wide ; and RA, which is here narrower, has its long axis passing 

 upwards from right to left, whereas in all Hall's figures it passes 

 upwards from left to right. In short, if there is a species of Bot- 

 ryoerinns to which one would have thought it impossible to refer 



