REVISION OF PALEOZOIC STELLEEOIDEA. 161 



which alternates with those of the supramarginal plates. The 

 latter are slightly tumid, subquadrate in outline, regular in size, 

 but decreasing gradually distally. Outside of these and margining 

 the rays may bo seen a little of the inframarginalia, which bear pairs 

 of short, slender, and finely striated spines. There are from 31 to 

 33 closely adjoining plates in each one of the abactinal columns; 

 there appear to be no accessory plates of any kind in the rays. 



Disk circular in outline, somewhat tumid and covered by small 

 many-sided plates that originally appear to have been closely adjoin- 

 ing. 



Remarks. — As this is the only American starfish with more than 

 five rays, it is readily distinguished from all othere. The abactinal 

 arm structure is practically that of Iludsonaster, with the difference 

 that in L. hdbcocki the inframarginals do not project beyond the 

 supramarginals and are therefore not seen as a rule from the dorsal 

 side in the natural casts. 



Locality and formation. — The holotype, an excellent specimen, was 

 found in the lower part of the Upper Devonic, near Ithaca, New 

 York, by Mrs. G. W. Babcock, after whom the species is named; 

 it is in her possession. The writer's attention was called to this 

 interesting specimen by Prof. H. S. Williams of Cornell Univei-sity, 

 Some years after this starfish was described in manuscript, Clarke 

 directed attention as above cited to two others found in the Cashaqua 

 shales of the Portage in Hunt's quarry, at Interlaken, New York. 



Cat. No. 60627 (cast), U.S.N.M. 



FAMILY, unknown. 

 Genus ASTROPECTEN Link. 



The genus Astropecten is based upon living species, and it is not 

 probable that the Devoiiic forms are identical. 



ASTROPECTEN (?) SCm^UTERI Sturtz. . 



Aslropeden schliileri Sturtz, Palseontograpliica, vol. 32, 1886, p. 87, pi. 10, figs. 1, 

 16, 2, 2a; Verb, naturh. Ver. j^reuss. Rheinl., etc., vol. 50, 1893, pp. 51, 71. 



In the roofing slates of the Lower Devonic at Bundenbach, Ger- 

 many. A single very much distorted and compressed example is 

 the basis of this species. 



Genus ATAXASTER Jaekel. 

 Ataxaster i A.is.K^h, Zeits. geol. Gesell., vol. 55, -1903, Protokol, p. 14 (106). 

 GenoJiolotype and only species. — A. pygmxus Jaekel. Ordovicic 

 (Dj), St. Benigna, Bohemia. 



Description. — "A small asterid whose ambulacrals in the distal 

 parts are alternate, but in the proximal are opposite." 



RemarJcs. — The above is all that is known about Ataxaster, and 

 for the present the genus has no value. 



