Yol.  49.] 
WEST  OF  CAEEMAETHEX. 
169 
On  the  northern  side  of  the  anticlinal,  the  presence  of  the  Llan- 
deilo  Limestone  has  not  been  absolutely  determined.  At  Llanglyd- 
wen  the  beds  with  4  tuning-fork  ’  graptolites  are  found  on  the 
.southern  side  of  the  4  Castell,’  while  Dieranograptus- shales  are  seen 
on  the  northern  side.  The  Llandeilo  Limestone  should  come 
between  these,  and  ma}T  he  faulted  out,  or  it  may  be  present  and 
not  exposed.  The  rock  at  Llanglydwen  marked  as  limestone  on  the 
Geological  Surve}^  map  is  an  ash.  A  sandy  limestone  is  seen  by  the 
roadside  north  of  Penlan,  near  Mydrim,  dipping  N.E.  At  Mydrim, 
where  the  Dieranograptus- beds  occur  north  of  the  village  and  dipping 
northward,  the  church  stands  on  black  shales  with  nodules  of  lime¬ 
stone,  which  may  represent  the  Llandeilo  Limestone. 
South  of  Mydrim,  some  gritty  shales  are  found  in  a  quarry  south 
of  Pant-rhendref.  They  contain  many  Trinuclei ,  together  with 
Aeidaspis  and  Bellerophon,  and,  as  they  intervene  between  the  shales 
with  4  tuning-fork  ’  Didyrnograpti  and  the  Dieranograptus- shales 
north  of  Mydrim,  they  may  be  parts  of  the  Llandeilo  Limestone 
Series.  The  species  have  not  been  determined,  but  the  rock  does 
not  closely  resemble  any  member  of  the  Llandeilo  Limestone  in  the 
vicinity,  and  beds  of  a  different  age  may  possibly  be  folded  or  faulted 
in  here.  These  beds  certainly  merit  a  further  examination. 
4.  Dieranograptus- shales. — On  the  southern  side  of  the  anti¬ 
clinal,  these  shales  with  characteristic  graptolites  are  found  near 
St.  Clear’s,  where  a  list  of  fossils  was  long  ago  recorded  by  Prof. 
Lap  worth  from  the  graptolitic  shales  of  that  place.1  Graptolites 
may  also  be  seen  in  the  shales  of  a  section  on  the  second  4 1  ’  of 
Llandowror  (on  the  Survey  map),  where  Climacograptus  tubuliferus, 
Lapw.,  is  abundant. 
On  the  northern  side  of  the  anticlinal  the  Dieranograptus ales 
occur  at  Dyffryn-pwdrim,  near  Llanboidy,  with  Dicellograptus  and 
Orthis  argentea ,  His.,  also  in  the  following  places  at  and  near 
Mydrim  : — North  of  Mydrim  Church,  Maenllwyd,  Llangarth-gynin, 
and  north  of  Penlan.  Much  work  remains  to  be  done  in  these 
highly  convoluted  shales,  which  have  already  yielded  so  many 
Hartfell  species,  and  which  will  no  doubt  furnish  characteristic 
Glenkiln  forms  after  further  search. 
5.  Robeston  Wathen  and  Sholeshook  Limestones. — These 
Caradoc  and  Upper  Bala  Limestones  are  often  welded  together,  so 
that  it  is  difficult  to  separate  them,  without  minute  examination  of 
the  forms.  The  two  formations  are  possibly  represented  at  Llan¬ 
dowror,  near  St.  Clear’s,  where  the  following  fossils  have  been  found 
in  a  limestone  which  is  like  the  Sholeshook  Limestone  : — 
Galymene  senaria ,  Cour. 
Cheirurus  juvenis,  Salt. 
- bimucronatus,  Murch. 
Cybele  verrucosa,  Dalm. 
The  same  formations  may  also  be 
Illcenus  Bowmanni,  Salt. 
Stygina. 
Orthis  calligramma,  Dalm. 
present  (one  of  them  certainly  is) 
1  Ann.  &  Mag.  Nat.  Hist.  ser.  5,  vol.  iv.  (1879)  pp.  339-340. 
