60 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



of H. narrawayi. In the holotype of this species, here illustrated, 

 are seen additional pairs of oral armature ossicles. These are situated 

 directly above or dorsal to the pairs of large armature plates, and are 

 probably overlapping ambulacralia modified into the actinostomial 

 ring. 



Locality and formation. — In the Black River formation, as follows: 

 The holotype was found by Mr. J. E. Narraway at City View, near 

 the Central Experimental Farm at Ottawa, Canada; it is now in his 

 private collection. An excellent specimen was found b}^ Mr. 

 Townshend near Kirkfield, Ontario, and is now in the Peabody 

 Museum of Yale University. Many years ago Dr. Ulrich found a 

 fine specimen at St. Paul, Minnesota, and another good one in the 

 Lower (Glade) Lebanon limestone of the Stones River series at 

 ShelbyviUe, Tennessee. These two specimens are in the United 

 States National Museum (Nos. 60602, 60619). Mr. Moritz Fischer 

 secured a coarsely silicified individual of this genus at Curdsville, 

 Kentucky, and this is now in the Beecher collection in the Yale 

 Museum; it may, however, prove to be of another species, distin- 

 guished by its stouter appearance, wider disk, and smaller axillary 

 plates. 



Remarlcs. — Originally the writer included specimens of this form 

 under P. matutinus, regarding them as but young individuals of 

 Hall's species. However, as the specimens are all geologically older, 

 are always smaller and stouter, and with fewer plates in aU of the 

 columns, Hudson's species is retained as valid. It is the ancestral 

 form and the most primitive species of Hudsonaster and hence the 

 most primitive Paleozoic starfish. It is primitive because of its 

 extreme simplicity of structure, in that the columns and plates are 

 reduced to the smallest number and all of them are closely adjoining 

 and without intercalary plates of any kind. Then the spines are 

 developed only on the actinal side and as protection for the podia. 

 For further information see generic remarks under Hudsonaster. 



Cat. Nos. 60602, 60619, U. S. N. M. 



HUDSONASTER MILLERI, new species. 



Plate 4, fig. 2. 



Description. — Of this form there is at hand but a single poorly 

 preserved individual showing the actinal side. It is a more slender 

 species than H. matutinus, has a larger and more rectangular axillary 

 plate, and the proximal inframarginals have each about 13 to 15 

 plates and the adambulacrals from 18 to 20. No ambulacrals are 

 preserved. The specimen measures: R = about 12 mm., r = 3 mm. 

 Width of ray at base 4 mm., at mid-length 3 mm. 



Locality and formation. — Found by Prof. Arthur M. Miller, after 

 whom the species is named, in the Lower Lexington (Wilmore) 



