REVISION OF PALEOZOIC STELLEROIDEA. 189 



in the Tale Museum Collection. These show both sides of the species. 

 U. asperula is said to be common in the roofing slate of the Lower 

 Devonic at Bundenbach, Germany. 



There can be no doubt that Asterias asperula Roemer is a true 

 UrastereTla. All the generic characters are shown, even the longi- 

 tudinally grooved spines and the rodlike extensions of the ambital 

 plates. For further remarks on this species see generic discussion. 



The abactinal structure of Roemeraster asperulus reminds one much 

 of UrastereTla pulcJiella of the Trenton, which is the least specialized 

 species of the genus. The single interbrachial plate retained to 

 maturity reminds one of the young of U. ulrichi. In this character 

 U. asperula appears to be primitive. In the proximal third of the 

 rays in U. asperula the radial columns are the most marked and the 

 plates continue to increase in size toward the disk. The supramar- 

 ginals are also well developed proximally, but the two or three 

 proximal plates are smaller and depressed, so that the ten basals 

 along with the five radials do not make so prominent a ring of large 

 ossicles as in U. pulcJiella or in the young of U. ulrichi. Distally 

 the rays in U. asperula have the plates of nearly equal size, although 

 the columnar and quincuncial arrangement is retained. The center 

 of the disk is occupied by a prominent central disk-plate and the 

 first ring consists of five radial plates as in U. pulcJiella. 



Cat. No. 59382, U.S.N.M. 



URASTE3ELLA, ne\7 species. 



In the paleontological museum of Cornell University there is a 

 large slender-rayed specimen having the general form and structure 

 of Urasterella. There is, however, so little of the actinal detail pre- 

 served that nothing more can be done than to indicate the presence 

 of this species. 



The specimen was found by Mr. J. B. Woodworth at Brookton, 

 near Ithaca, New York, in the Upper Devonic. 



URASTERELLA MONTANA (Stschurowsky). 



Palseaster montanus SCHONDORF, Palseontographica, vol. 56, 1909, p. 324, pi. 23, 

 fig. 1; pi. 24, figs. 20-22 (complete bibliography cited here). 



In general this form recalls U. grandis but is somewhat smaller and 

 stouter. The actinal side alone is known, showing a wide ambu- 

 lacral furrow bordered by stout columns of narrow adambulacrals. 

 All of the ossicles of the ambulacrals and adambulacrals are opposite 

 one another. Oral armature decidedly adambulacral in composition. 

 Interradial areas described as having "a few plates." A section 

 through a ray (Schondorf s fig. 22) shows that abactinally on each 

 side of the radialia there are four columns of ossicles, or nine in all. 



Dimensions, about: E, = 35 mm., r = 6-7 nun., R 6r. Width 

 of ray at mid-length about 6 mm. 



