SYSTEMATIC LIST OF LOWER PALZZOZOIC FOSSILS. 345 
ae ane Genera and Species, with the localities represented by the ate ae Genera and Species, with the localities represented by the 
scribed numbers of the preceding List, under each aoribed numbers of the preceding List, under each 
above. Geological Group. above: Geological Group. 
254 
263 
| LINGULA (continued). 
— tenuigranulata (M°Coy). 
Upper Bala, 7—80. 
SPONDYLOBOLUS. 
'— craniolaris (M°Coy). 
Upper Bala, 30. 
AVICULA. 
— Danbyi (M°Coy). 
Upper Ludlow, 18. 
— orbicularis (Sow.) 
Caradoc sandstone, 2. 
PTERINEA. 
— asperula (M°Coy). 
Upper Bala, 30. 
— Boydi (Conrad Sp.) 
Upper Ludlow, 23. 
— demissa (Conrad Sp.) 
Upper Ludlow, 18—210. 
Lower Ludlow, (169). 
Wenlock shale, 173—(169). 
— hians (M°Coy). 
Upper Ludlow, 181. 
— lineata (Gold.) 
Upper Ludlow, 18. 
Wenlock shale, 173. 
— megaloba (M°Coy). 
Upper Ludlow, 236. 
— pleuroptera (Conrad). 
Upper Ludlow, 18. 
Ludlow Group, 194. 
Upper Bala, 54. 
— retroflera (Wahl. Sp.) 
Upper Ludlow, 119. 
— — Var. a. 
Upper Ludlow, 18—117. 
Lower Ludlow, 186. 
— erect, Var. 5 
Upper Ludlow, 134. 
— — Var. naviformis. 
Upper Ludlow, 130—127, 
Wenlock limestone, 91. 
— Sowerbyi (M°Coy). 
Lower Ludlow, 136, 
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| PTERINEA (continued). 
— subfalcata (Conrad Sp.) 
Upper Ludlow, 18—210. 
Wenlock shale, 123. 
— tenuistriata (M°Coy). 
Upper Ludlow, 18—31—163—210. 
Lower Ludlow, 94. 
Ludlow Group, 194—75. 
Wenlock shale, 173. 
Upper Bala, 218. 
AMBONYCHIA. 
— acuticostata (M°Coy). 
Lower Ludlow, (84). 
Wenlock shale, (84). 
— striata (Sow. Sp.) 
Ludlow Group, 194. 
Lower Ludlow, 136—101. 
Upper Bala. 54. 
MYTILUS. 
— unguiculatus (Salt.) 
Caradoc sandstone, 209. 
MODIOLOPSIS. 
— antiqua (Sow. Sp.) 
Upper Bala, 103. 
— complanata (Sow. Sp.) 
Upper Ludlow, 130—236. 
— expansa (Port.) 
Upper Bala, 164. 
— inflata (M°Coy). 
Upper Bala, 73—197. 
— modiolaris (Conrad Sp.) 
Caradoc sandstone, 120—121. 
Upper Bala, 166—35. 
— Nilsoni (His. Sp.) 
Ludlow Group, 194. 
Wenlock shale, 173. 
— platyphylla (Salt. Sp.) 
Upper Ludlow, 236. 
— postlineata (M*Coy). 
Upper Bala, 7. 
— solenoides (Sow. Sp.) 
Upper Ludlow, 18—236, 
Vex 
