FOSSILS OF THE FREMONT LIMESTONE. 101 



X 



( )f this fauna Halysites catenidatus, Columnaria alveolata, Strophomena 

 alternata, Streptdrhynchus filitextum, Orthis subquadrata, Rhynchonella capa 

 var. increbescens, Endoceras proteiforme, Asaphus platycephalus (?), and 

 Illsenus milleri extend up to the next strongly marked fossiliferous horizon, 

 215 feet above. Without exception, all these species have an extended 

 vertical range in the Silurian (Ordovician) strata either in North America 

 or Europe. The fact that 25 of the 27 identified species arc identical 

 with those of the Trenton fauna of Wisconsin and New York is sufficient 

 to locate the horizon in the Ordovician fauna. Halysites catenidatus is not 

 known from the Trenton zone elsewhere in America; hut in Wales it 

 ranges through the Bala and the subjacent Llandeilo. Orthis flabellumis 

 also a Bala species. There is nothing among the unidentified species to 

 indicate a higher horizon than the Trenton of the New York section. 



Scattered and fragmentary fossils occur in the 225 feet of superjacent 

 limestone; hut it is in the beds 225 to 24N feet above the Harding sand- 

 stone that the fauna is best preserved. From this zone the following 



species have heell collected : 



ACTINOZOA. 



i 



Streptelasma cornicidum, Hall. Pleurodictyum, n. sp. 



" 2 n. sp. Halysites c<if<'iiiilaiii*. Linn. 



Columnaria alveolata, Goldfuss. Monticvlipora, 2 sp. ? 

 Favosites gothlandicus, Lamark. 



ECHINOZOA. 



Loose plates or segments of crinoi- Cyclocrinus, sp.'.' 



dal columns. 



BRACHIOPODA. 



Leptsena sericea, Sowerby. Streptorhynchus planoconvexus, Hall. 



sp. undet. " planumbonus, Hall. 



Strophomena alternata, Conrad. " subtentum, Conrad (?). 

 alternata var. nasnta, Orthis subquadrata, Hall. 



Conrad. " testudinaria, Dalman (?). 



Strophomena deltoidea, Conrad. Rhynchonella capax, Conrad. 



Streptorhynchus filitextum, Hall. capax var. increbescens, 



nutans, .lames. I [all. 



LAMELLIBRANCHIATA. 



Pterinea, sp. undet. Tellinomya ventricosa, Hall. 



Tellinomya dubia, Hall (?). Cypricardites, '■'> sp. undet. 



levata, Hall (?). Modiolopsix faba, Conrad. 



naxnta, Hall. " sp. ? 



XXI Hi i i. Soi . \m . Vol . :. 1891. 



