REVISION OF PALEOZOIC STELLEROIDEA. 211 



The madreporite in P. (?) gyalum, as in the forms of Palseosolaster, 

 is very large, actinal in position, and placed even closer to the mouth 

 than in any other species. Not only this, but it lies completely cov- 

 ering one proximal ambulacral furrow and across parts of two adja- 

 cent rays. Its general position and size are in harmony with Palseo- 

 solaster and not at all with Helianthaster. 



That P. (?) gyalum can not be referred to Heliantliaster is therefore 

 seen in the diflerent position of the madreporite, the greater number 

 of rays, the wider ambulacral furrow, and the improbability of its 

 having three columns of abactinal ray plates in place of an integument 

 bristling wath spines. All of these dilTerences are in harmony with 

 Palseosolaster. Further, if P. (?) gyalum had interbrachial inframar- 

 ginals as does Helianthaster, they should show somewhere on these 

 five specimens, all of which preserve the actinal side. \^Qiile these 

 differences may not apj^ear to be great, they make of Helianthaster a 

 phanerozonian and of Palseosolaster a cryptozonian. 



PAL^OSOLASTER ROEMERI (Clarke). 



Heliar.thaster roemeri Clarke, Bull. N. Y. State Mus., No. 121, 1908, p. 64, pi. 11. 



From the Lower Devonic of Bundenbach, Germany. The holo- 

 tyjye is in the New York State Museum. 



Genus ECHINASTERIAS Stixrtz. 



Echinasterias Sturtz, Verh. nat. \'er. preuss. Rhoiul., etc., vol. 5G, 1900, p. 230, 

 pi. 2, fig. 4; pi. 3, fig. 5. 



The genotype has 25 rays, but otherwise appears to have all the 

 generic characters of Palseosolaster. 



Gcnoliolotype and only syecies. — E. spinosus Sturtz (citations as 

 above). Lower Devonic of Bundenbach, Germany. 



Genus ECHINODISC ASTER Delage and Herouard. 



Ediinodiscns Stxjrtz (not Echinodiscus Wortlien and Miller 1883, Ecliiuoidea), 

 Verh. nat. Ver. preuss. Rheinl., etc., vol. 56, 1900, pp. 231-233, i)l. 3, figs. 

 6-10. 



Echinodiscasler Delage and IIerouakd, Traitc de Zoologie Concrete, 1904. 



Echinodiscites Schuchert, Fossilium Catalogiis, Animalia, pt. 3, 1914, p. l5. 



One of the specimens has 29 rays and a greatest diameter of 160 

 mm. The writer fails to see how this genus is to be distinguished 

 from Palxosolaster. It may be more abundantly spinoso, and the 

 madreporite is somewhat smaller and more coarsely striate, but these 

 characters can hardly be of generic value. 



Genoliolotype and only species. Echinodiscus multidactylus Sturtz 

 (citations as above). Lower Devonic of Bundenbach, Germany. 



Cat. No. 59386, U.S.N.M. 



