EXTRA-BRITISH ASTEROIDEA. Ill 



" ]>i mentions. — Diameter of disc iimi. Length of arm 20 mm. Width of 

 arm near disc 1'25 mm." 



Rpmarkx. — The figures given and dimensions of this species appear to me to 

 indicate tliat it closely resembles Ophiot'itanos Ixris. The upper arm-plates are 

 described as hexagonal, and the more proximal upper arm-plates of the British 

 species present this appearance. 



Localitij and Stvatigraphical Position. — Cretaceous, Fort Ellis, Montana. 



OriiiO(ii,YriiA TioxAXA, Clad; 1892. 'Bull. U.S. Geol. Survey,' no. 97, p. oU. 



"Determinative Characters. — Disc round; composition indistinct. Arms long, 

 with wedge-shaped under ai'in-plates about as wide as long; upper ann-plates 

 about twice as wide as long. 



" jD/jhc»6v'oh.s-.— Diameter of disc 15 mm. Length of arm 5() mm. Width of 

 arm at disc 2 mm." 



Iiemarl-s. — It is difficult to identify this with a British species, but the illus- 

 trations appear to indicate that it is somewhat similar to Awphinra cretacea. 



Localiti/ and Stratiijyajjhical Position. — Cretaceous, six miles north of Fort 

 AVorth. 



OriiiriJA OKANn.osA, Tuicno'r, 1841. 'Die Verstein. norddeutsch. Kreidegeb.,' yi. 



28, pi. vi, fig. 22. 



This species is described as follows : 



" Die Arme sind walsenformig und bestehen aus gewolbten, seitlich durch ein 

 Furche getrennten, deutlich gekornten Seitenschildchen ; wo sich deren vier 

 beriihren liegt ein kleines, dreieckiges Sehildehcn da/.wischen." 



Rcmarls. — The small fragment of the arm figured shows it to be a portion 

 of the distal extremity— cpiite possibly (he distal extremity of some species of 

 OjMotitanos. 



JjOcaVifij and Slrafiijrajihical Position. — Lower Chalk, Liudener Berg, near 

 Hanover. 



