Yol.  49.]  LLANDOVERY  AND  ASSOCIATED  ROCKS  OE  CORWEN. 
439 
Beds  not  far  below  the  Corwen  Grit. 
Leptcena  sericea,  Sow.  (abundant). 
Strophomena  rhomboidalis,  Wilck. 
Orthis  elegantula ,  Dalm.  (abundant). 
- testudinaria  ?  Dalm. 
- protensa,  Sow. 
- calligramma  ?  Dalm. 
- porcata  ?  M'Coy. 
Conularia  Sowerbyi,  Defr. 
Holopea  striatella?  M‘Coy. 
Pkyllopora  Hisingeri,  M'Coy. 
Ptilodicfya  dichotoma,  Portl. 
- explanata,  M'Coy. 
Pinnatopora  Sedgwicki,  Shrubs. 
FJcenus  sp. 
Crinoids  (abundant). 
Favosites  fibrosa,  Goldf.,  and  other 
Favositid  corals  (abundant). 
Dendrograptus  ? 
Lower  Beds. 
Leptcena  sericea,  Sow.  (abundant). 
Atrypa  marginalis,  Dalm. 
Orthis  elegantula,  Dalm.  (abundant). 
- porcata  ?  M'Coy. 
- testudinaria,  Dalm. 
Conularia  Sowerbyi,  Defr. 
Pinnatopora  Sedgwicki ,  Shrubs. 
Trinucleus  seticornis,  His. 
Calymene  senaria ,  Com*ad. 
Illcenus  Bowmanni ,  Salt. 
Crinoids  (abundant). 
Favosites  fibrosa,  Goldf.,  and  other 
Favositid  corals. 
Glyn 
Grey  Slates 
Leptcena  sericea,  Sow. 
Meristella  crassa. 
Orthis  elegantula  ?  Dalm. 
- porcata,  M‘Coy. 
Ceiriog.1 
it-  Glyn  Ceiriog. 
Orthis  hirnantensis  ? 
Strophomena  rhomboidalis ,  Wilck. 
Fletzia  ? 
Calcareous  Grit  at  and  near  Glyn  Ceiriog. 
Leptcena  sericea ,  Sow.  (tolerably  abun¬ 
dant). 
- transversalis  ?  Dalm. 
Lingula  ovata ,  M'Coy. 
Orthis  biforata,  Schloth. 
■ - calligramma,  Dalm.  (abundant). 
- elegomtula,  Dalm. 
- porcata,  M'Coy. 
Strophomena  rhomboidalis,  Wilck. 
Pentamerus  ?  sp. 
Bhynchonella  Lewisii,  Dav. 
Meristella  cf.  nitida,  Hall. 
Ptilodictya  explanata,  M'Coy. 
Pinnatopora  Sedgwicki,  Shrubs,  (abun¬ 
dant). 
Calymene  sp. 
Homalonotus  bisulcatus  ?  Salt. 
Phacops  apiculatus,  Salt. 
Favosites  fibrosa,  Goldf.,  and  other 
Favositid  corals. 
Nebulipora  lens,  M'Coy. 
Heliolites  megastoma,  M'Coy  (tolera¬ 
bly  abundant). 
- tubulata  ?,  Lons. 
Streptelasma  equisidcaturn ?  M'Coy. 
IAndstroemia  subduplicata,  M'Coy 
(abundant). 
- ,  var.  crenulata,  M'Coy. 
Haly sites  catenularia  ?  Linn. 
Gasteropods  ( Pleurotomaria ,  Murchi- 
sonia,  Holopella,  Strap  nrollus,  Belle- 
rophon )  and  crinoids  often  abundant. 
Discussion. 
The  President  said  that  this  paper  contained  a  very  pretty  little 
bit  of  stratigraphical  work.  Tough  grits  were  of  great  value  in 
1  Glyn  Ceiriog  lies  about  8  miles  E.S.E.  of  Corwen.  Here  also  we  have  a  grit 
(calcareous)  succeeded  by  grey  slates  with  grit-bands,  as  at  Corwen;  but  both 
grit  and  slates  are  fossiliferous.  The  lists  are  inserted  for  purposes  of  com¬ 
parison,  to  supplement  the  poverty  of  the  corresponding  beds  at  Corwen. 
