CONODOXTS IN ARENIG-LLANDKILO FORMATIONS. 251 



Cornaramia bicornua. new species. 



The under side of the beam has a double concave curve. The 

 beam carries a strong tooth, which springs from its centre. Each 

 horn of the beam has three and five small teeth respectively; 

 Fig. 49. 



Locality. — Fardingmulloch, near Sanquhar; in chert-shale. 



]Vi:W GENUS, VALENTIA, Smith. 

 From a deep, thin plate a few long, slender teeth spring. 



Valentia morrochensis, new species. 



From a deep, thin, tapering beam, five long, straight teeth 

 spring at a slightly oblique angle; Fig. 50. 



Locality. — Morroch Bay, south of Portpatrick ; in green Arenig 

 shale. 



Explanation of the Plates. 

 Plate V. 



Ctntrodus trectus. Smith, new species. Figs. 1,2, 4, 5, page 244. Hunt 

 Law Cleugh and Ravengill. 



Ceiitrodu'< obliquua, Smith, new species. Fig. 3, page 244. Hunt Law 

 Clouch. 



Oentrodus distans. Smith, new species, Fig. 7, page 244. Ravengill. 



Polygnathus parvus, Smith, new species, Fig. 6, page 245. Normangill. 



Polygnathtis minus. Smith, new species, Fig. 8, page 245. Glencaple. 



Polygnathus princeps, Hinde, Figs. 9, 10, 12, 13, page 245. Hunt Law 

 Cleuch. 



Polygnathus curvatus, Smith, new species. Fig. 11, page 245. Hunt Law 

 Cleuch. 



Polygnathus pauptro.tun. Smith, new species, Fig. 14, page 245. Hunt 

 Law Cleuch. 



Polygnathus dubius, Hinde, Fig. 15, page 245. Hunt Law Cleuch. 



Polygnathus lanceolatus, Smith, new species, Fig. 16, nage 245. Hunt 

 Law Cleuch. 



Plate VI. 



Machairodia sulcata, Smith, new species. Fig. 17, page 246. Ravengill. 



Machaii-odia rhombea, Pander, Fig. 19, page 246. Ravengill. 



Drepanodus flexuosus. Pander, Fig. 18, page 24G. Hunt Law Cleuch. 



Comuramia monodonta, Smith, new genus and new species, Fig. 20, 

 page 246. Ravengill. 



Comuramia diplodonta. Smith, new species. Fig. 25, page 246. Ravengill. 



Pachysomia ivanloektnsis. Smith, new genus and new species. Fig. 23, 

 page 246. Waulock ^Yater. 



