ART. 22 RICHMOND FAUNAT. ZONES AUSTIN 9 



Fort Ancient division — Continued. 



AnomoAodonta g'Kjantea bed (W. :'.). rurer blue linie.stone beds inter- 

 bedded with shale, with niau.v iielecyiiods, partieularly Anoinalodonia 

 ffiffantea, A. uhtta, Pholudoniorpha phoJadiformix, Pterinea demissa, etc., 

 at their greatest development 12' 



Rafinesquina loxorhytis bed (W. 2). Argillaceous blue limestone beds 

 alternating with more or less heavy layers of shale. P^ossils rather few. 

 R. alteniata, R. loxorhytis, DahnanelJa meelci, etc 40' 



Strophomena^ concordensis bed (W. 1). Massive, nodular, light blue argil- 

 laceous limestone with little clay, i-ather unfossiliferous )nit containing 

 Strophoineua concorde^isis, (Jyvloneuui htunerusmn, Anoiiuilodfnitn ahifa, 

 and Rafiueftquina species ^ .5' 



Arnhciin foniKiflon (Beds A. l-o) 



Oregouia division (Beds A. 2, 3). 



Homotrypa, hus-'<leri beds (A. 3). Dark blue shaUs and lumpy, rubbly, 

 argillaceous limestone crowded with fossils; Cyclonema ftactuatum, 

 Anomalodonta alata, A. gigantcu, Mesotrypa orhiculata, Homotrypa hass- 

 leri, Batostoma varians, and many microscopic fossils (species of Cyclora, 

 I^riiniiia cincinnatiensis, Bollia regnluriis, Ctetwholbinu humuu'llK Apar- 

 chites ohiongus, etc.) 20' 



Dinorthis carleyi bed (A. 2). More even bedded blue limestone alternating 

 with beds of clay with valves and entire exajuples of this characteristic 

 species and also Leptaena richtnondennia precursor and Plntystrophla 



ponderosa 3'-5' 



Sunset division (A. 1). Rather unfossiliferous, light drab colored claj'S 

 alternating with thin layers of clay stone of the same color, which con- 

 trasts strongly with the Mount Auburn beds below and tlie Oregonia 

 above. Rafinesquina alter^iata var. common at the bottom and near the 

 top. Cyclonema fliictuatum, Peronopora dccipiens, and Pterinea dcmissa 

 usually found 20' 



Maysville Group (Ordovician). 



RICHMOND FOSSILS IN WARUBN AND CLINJIiN COUNTIES, OIIIO, S)IOWIX(; STATIGRAPHIC RANGE 



Acrolichas shidrlcri (Foerste). Wh. 1. 

 Agelacrinns austinl Foerste, Wh. 0. 

 Agelacrinus rectiradiattis (Williams), L. 3. 

 Anomalodonta alata (Meek), A. 3, W. 2. 

 Anomalodonta gigantea Miller, A. 3, W. 2. 

 Aparchites minutissimus (Hall). A. 3. 

 Aparchites ohiongus Ulrich, A. 3. 

 Arabellites procursus Foerste, E. 3. 

 Archinacella richmMHlensis Ulrich, Wh. 5. 

 Arctinurus harrisl (Miller), Wh. 1. 

 Arthraria hiclavata Miller, A-E. 

 Arthropora shafferi (Meek), W. 3, 8, Wh. 2, 5, 6. 

 Arthropora shafferi, var. robusta Ulrich, L. 2. 

 Atactopora angularis Ulrich and Bassler, W. 

 Atactoporella schucherti Ulrich, W. 

 Ateleocystites balanoides (Meek), W. 13. 

 Batostoma variabile (Ulrich), Wh. 4. 

 Batostoma varians (James), AV. 3, 5, 6, 8; A. 3. 

 BelleropJwn mohri Miller, Wh. 3, E. 3. 



27616—27 2 



