IJST OF l,(H ISVIIJ/K, [ilMKS'l'ONK FOSSILS. 



411 



shows that 76 per cent, of the Laurel brachiopods are present in 

 the Waldron. 



The list affords no information regarding the groups Felecy- 

 poda, Gasteropoda, and Conularia, each of which will probably 

 eventually be found to be represented in the Laurel fauna. 



In the Cephalopod group the Waldron and Laurel faunas are 

 rei)resented by about equal numbers of species according to the 

 lists, the former having 8 and the latter 6 species. Two are com- 

 mon to the two faunas; thus showing a percentage of 33 1-3, which 

 survived the Waldron shale conditions of sedimentation. 



The Crustacea at present known in the Laurel fauna numbers 

 but four species. Two of these or 50 per cent are present in the 

 Waldron fauna. 



These comparisons show that while the Waldron fauna is rather 

 closely allied to its predecessor through the Brachiopoda and the 

 Cephalopoda, it introduced in the Pelmatozoa a faunal element en- 

 tirely new to the region. 



Very few fossils have ever been found in the Louisville lime- 

 stone in the region where the Waldron fauna is best developed. 

 But at Louisville the formation contains an abundant fauna, which 

 has been made known through the work of Nettleroth, Hall and 

 others. In order to compare the Waldron fauna with its successor, 

 the Louisville fauna, and to note the general effect on the compo- 

 sition of the fauna of a change from shale to limestone conditions 

 of sedimentation, a list of the latter, which follows, has been com- 

 piled : 



Fauna of the Louisville Limestone at Louisville.'' 

 Spongia. 



Cyathospongia excrescens H. & W. 



Hydrozoa. 



Dictyonema pergracilis H. & W. (H. & W.) 



Anthozoa. 



Heliolites megastoma McCoy. ( Davis. )^ 

 Heliolites interstinctus Linnaeus. (Davis.) 

 Heliolites pyriformis Guettard. (Davis.) 



a This list is compiled mainly from the papers of Hall (24th and 25th Ann. 

 Kepts. N. Y. State Mus.'Nat. Hist.) ; Nettleroth (Ky. Fossil Shells, Ky. Geol. Siirv.), 

 and Davis (Ky. Fossil Corals, Ky. Geol. Surv.). 



^ The authority for pafh specios is sriTon in paronthpsis after it. 



