II. J. Seymour — Blue Amphibole in Hornblende. 257 



somewhat peculiar, though in the complete margin and number of 

 segments it agrees with Parabolinella. To Olenus used in a generic 

 sense this species may certainly be referred. Salter's ^ species with, 

 the same name is distinct from Belt's, but belongs to the Olenidae. 



From the above revision the so-called species of Conocoryphe in 

 Britain should be designated as follows : — 



Eidoma abdition. Conocoryphe Lyelli. 



Solenoplcnra applanata. Peltiira'i malvernia. 



Olenus ? Imcephalaa. Euloma monile. 



Conocoryphe {Bailiella) hufo. Conocoryphe'^ perdita. 



Ctenoccphahis coronatus. Olenus [Paraholinella) Planti. 



Solenopltura? depressa. Olenus [Cyclognathus) simplex. 

 Feltura, sp.[ = C? ecorne ? (Ang.), Salter]. Ctemcephalus [HarteUa) solvensis, 



Conocoryphe ? Homfrayl. Solenopleura ? variolaris. 



Olenoidcs hiiinerosus. Angelina verisimilis. 



Apafokephalus invitiis. Olenus {Parabolinella 1) Williamsoni. 

 Olenus {Parabolinella?) longispina. 



The three species of whicb the genera even are doubtful are 

 C. ? olenoides, C. vexata, and C. viola. But none of these three can 

 be attributed to Conocoryphe, and their true position must be left to 

 the future to decide. 



The distribution of the tabulated forms is as follows : — 



Haelech Series. Olenus ? hucephalus. 



Conocoryphe Lyelli. Feltura, sp. 



Ctenocephalus {HarteUa) solvensis. Apatohephalus invitus. 



Menevian. Olenus {Parabolinella?) longispina. 



Solenopleura applanata. Peltura ? malvernia. 



Conocoryphe {Bailiella) hufo. Olenus {Parabolinella) Planti. 



CtcnoctpJialus coronatus. Olenus {Cyclognathus) simplex. 



Conocoryphe? llomfrayi. Olenus {Parabolinella?) Williamsoni. 



Olenoides humerosus. Tremadoc. 



Conocoryphe ? perdita. Solenopleura ? depressa. 



Solenopleura ? variolaris. Euloma monile. 



LiNGULA Flags. Angelina verisimilis. 



Euloma abditum. 



The genus Conocoryphe, sens, str., is thus seen to be confined in 

 Britain to the Lower and Middle Cambrian beds. 



V. — On the occurrence of a Blue Amphibole in a Hornblende 



Kersantite from Co. Down. 



By Henry J. Seymour, B.A., F.G.S., of H.M. Geological Survey of Ireland. 



(Communicated by permission of the Director- General.) 



IN connection witli the revision of the Silurian area in Ireland, 

 at present in progress by the staff of the Irish branch of 

 the Geological Survey, a number of rock-specimens of the dykes 

 occurring on the coast of Co. Down were lately petrographically 

 examined by the writer, who detected in one of the slices a blue 

 amphibole of secondary origin. As a mineral of this kind was not 

 hitherto known to occur in situ in Ireland, it may be of interest to 

 put its discovery on record here and to give also a few details 

 respecflng its characteristics, 



1 Cat. Camb. Sil. Foss. Woodw. Mus., 1872, p. 12. 

 decade IV.— vol. VH. — NO. TI. 17 



