188 C. D. Walcott — Fauna of the Upper Taeonic 



Thirty-five species and one variety were found in the even- 

 bedded and conglomerate limestones and the associated slaty 

 argillaceous and siliceous shales. Of these eleven species and 

 one variety were unknown before and are described in this 

 paper. The geographic distribution of the others is given in 

 Bulletin 30, with the exception of their occurrence in Washing- 

 ton County. 



The following is a list of the species now in the collections 

 of the U. S. Geological Survey, from Washington County : 



Protospongia (loose spiculae). 

 Ethmophyllum (fragment). 

 Lingulella ccelata Hall (sp.). 

 Lingulella Granvillensis, n. sp. 

 Lingulella, sp. undet. 

 Linnarssonia Taconica, n. sp. 

 Kutorgina pannula White (sp.). 

 Obolella, sp. iiDdet. 

 Orfhis, sp. undet. 

 Orthis Salemensis, n. sp. 

 Ca-maretta, sp. ? 

 Fordilla Troyensis Barrande. 

 Modiolopsis (?f) prisca, n. sp. 

 P/atyceras primazvum Billings. 

 Hyolithes Americanus Billings. 

 Hyolithes communis Billings. 

 Hyolithes impair Ford. 

 Hyoliihellus micans Billings. 



Hyolithellus micans tar. rugosa, n. var. 

 Stenotheca elongata Walcott. 

 Stenotheca rugosa Hall (sp.). 

 Aristozoe rotundata, n. sp. 

 Aristozoe Troyensis Ford. 

 Leperditia (I) dermatoides, n. sp. 

 Microdiscus connexus. n. sp. 

 Microdiscus lobatus Hall (sp.). 

 Microdiscus speciosus Ford. 

 Olenellus asaphoides Emmons. 

 Olenoides Fordi, n. sp. 

 Solenopleura (?) Nana Ford. 

 Solenopleura (?) tumida, n. sp. 

 Conocorphye trilineata Emmons. ' 

 Ptychoparia, like P. Adamsi. 

 Ptychoparia (?) Fitchi, n. sp. 

 Ptychoparia, sp. undet. 

 Ptychoparia (?) clavata, n. sp. 



Of the above, Lingulella Granvillensis, Linnarssonia Taconica, 

 Microdiscus connexus and Conocoryphe trilineata are types related 

 more closely to the Lower Cambrian than to the Middle Cam- 

 brian fauna. Stratigraphically, they occur low down in the 

 section, and I shall' not be surprised if other representative 

 species and some species identical with those from the Lower 

 Cambrian of St. John, N. B., or Newfoundland, are found at 

 about the same horizon. 



I have discussed the distribution of the Middle Cambrian or 

 Taeonic fauna in Bulletin 30, and the reader is referred to that 

 report for further information. 



In a report on the Geology of Washington County, now in 

 the course of preparation, a geologic map will show the distri- 

 bution of the formations and the localities of the fossils and the 

 vertical range of the latter will be given in the sections. 



Lhstgttlella Granvillensis, n. sp. 



Plate I, figs. 15-15c. 



Shell small, elongate ovate, margins sub-parallel for a short 

 distance at the widest portion about midway of the shell, 

 broadly rounded in front, ventral valve attenuate toward the 

 beak ; dorsal valve ovate and rounded at the beak. General 



