332 C. SCHUCHERT — LOWER HELDERBERG-ORISKANY FORMATIONS 



"At Saint Helens island and Round island, opposite Montreal, on isle Bizard, 

 and one or two neighboring localities, some outlying or small isolated patches of 

 conglomeratic rock, referred to the Lower Helderberg division, have been recog- 

 nized of late years. Their existence was first pointed out by Doctor Dawson. 

 They are made up of fragments of various rocks, gneiss, Trenton limestone, Utica 

 shale, syenite, etc., cemented together by a paste of grayish dolomite. These 

 conglomerates are regarded as patches of strata once continuous with the Lower 

 Helderberg series of New York." 



The Saint Helens Island fauna based on Donald's list contains : 



Farosites gotlandicus. Rhyneholrema formosum (Hall). 



Orthis (Rhipidomella) discus (Hall). IAssopleura sequivavia (Hall). 



Orthis [Rhipidomella) oblata Hall. Undnulus mutabUis Hall. 



Orthis (Rhipidomella) tubulistriata Hall. Uncinulus nucleolatus Hall. 



Orthis (Rhipidomella) eminens Hall. Camarotcechia ventricosa Hall. 



Hipparionyx proximus Vanuxem. A try pa reticularis Linne. Very abundant. 



Orthothetes deformis Hall? Stricklandinia gaspiensis Billings. 



Strophonella punctidifera (Conrad). Anastrophia verneuili (Hall). 



Sirophonella (?) radiata (Vanuxem). Gypidula g<deata (Dalman). 



Stropheodouta varistriata (Conrad). Gypidula pseudogaleata (Hall). Very 



Leptxaa rhomboidalis (VVilckens). abundant. 



Spirifer concinnus Hall. Very abundant. Diaphorostoma depressa (Hall). 



Spirifer cyclopterus Hall. Tentaculites helena Donald (has vertical 



Spirifer, allied to S. arenosus (Conrad). striae between theannulations). 



This assemblage of Silurian, Helderbergian, and Oriskany fossils is 

 remarkable, and the present writer hesitated to accept the identifications 

 of Mr Donald without further proof. He therefore wrote to Professor 

 J. F. Whiteaves, paleontologist of the Geological Survey of Canada, who 

 borrowed the specimens of Hipparionyx proximus and Spirifer allied to 

 S. arenosus, of McGill University and sent them to the writer. These 

 show that the Saint Helens Island fauna includes neither Hipparionyx 

 proximus nor u Spirifer allied to S. arenosus." Both these identifications 

 relate to a Spirifer apparently near S. granulosus Conrad of the Middle 

 Devonian. S. arenosus has a plicated fold and sinus, characters not 

 seen in Donald's specimens. His Spirifer concinnus Hall is more like 

 S. Cumberland! 'ie, but the bilobed fold of the dorsal shell is a character 

 which associates his species with S. mucronatus Conrad, of the Ham- 

 ilton. 



Under these circumstances, judgment is deferred as to the age of the 

 conglomerates on Saint Helens island. 



