DESCRIPTIVE NOTES OF NEW GENERA AND SPECIES FROM THE 

 LOWER CAMBRIAN OR OLENELLUS ZONE OF NORTH AMERICA." 



BY 



Charles D. Walcott, 



Honorary Curator of the Department of Invertebrate Fossils. 



The types of the new genera and species described in this paper are 

 in the collection of the National Museum, and may be identified by the 

 Museum catalogue number given with the description of each species. 

 The illustrations of the species will be published in the Tenth Annual 

 Report of the Director of the U. S. Geological Survey for the year 

 ending June 30, 1889. 



CORALS. 



It has been an open question for many years whether the forms 

 referred to the genus Archwoeyathus, Billings, were corals or sponges 

 (see Bull. U. S. Geol. Survey, No. 30, 1886, p. 78-80). Dr. G. J. Hinde 

 has recently reviewed the genera and species,! and concluded that 

 "the Archwocyathince form a special family of the Zoantharia sclero- 

 dermata, in some features allied to the group of perforate corals." 

 Although previously inclined to consider the forms under notice sponges, 

 I am now of the opinion that Dr. Hinde is more nearly correct in refer- 

 ring them to the corals. 



Protopharetra Bokaemann. 

 See Geol. Zeitschr., 1883, p. 274. 



Protopharetra sp. ? 



This is a form related to P. •polymorpha Borneniann. $ It varies in form 

 of groicth from round stems to flattened fronds, in which the structure 

 is very irregular. It is an open question if Spirocyathus atlanticus is 

 not generically identical with Protopharetra. 



Locality. — Silver Peak, Nevada. 



Nat. Mus. Cat. Invt. Foss., No. 15303. 



Spirocyathus Hinde. 

 See Quart. Jour. Geol. Soc., London, 1889, vol. 35, p. 136. 



This genus is proposed to include the original type of the genus 

 Archceocyathus, Billings. As the change to another type was made 



*Read before the Biological Society of Washington, June 1, 1889. 

 tQuart. Jour. Geol. Soc., London, vol. 45, 1889, pp. 125-148, pi. 5. 

 t Nova Acta L^op. Carol., Deutsche Acad. Nat url'orscher, vol.51, pt, 1, L886. 

 Proceedings National Museum, Vol. XII— No. 7<>:s. 



Proc. N. M. 89 3 ™ 



