230 Canadian Record of Science. 



the lowest Cambrian, as the slates and grits of Braj Head 

 were correlated with the Llamberis slates on the opposite 

 side of St. George's Chaniiel. But there is really no abso- 

 lute evidence fixing the age of these grits, as the oldest 

 fossiliferous horizon in this district, with determinable 

 trilobites, is Ordovician. 



On the continent of Europe Oldhamia has been found 

 in Cambrian beds from the Trimadoe downward. Prof. 

 C. Malaise has found it in the slates of the middle division 

 of the Cambrian of Belgium ; and also at the base of the 

 upper division (Salmien), which contains the Dictyonema 

 zone, he has found remains singularly like this fossil. 

 Prof. Jules Bergeron, who has studied the Cambrian system 

 in the soiith of Prance, found Oldhamia in the upper part 

 of the " Olemus Substagi." It may therefore be looked 

 for in any part of the Cambrian from the base to the 

 Dictyonema zone. 



Dr. Chas. Barrois has noted the existence of the genus 

 Oldhamia in the Cambrian rocks of the Pyrenees, but his 

 species (0. Hovelaquei) differs from 0. antiqua by its 

 greater size, by the frond not being jointed appendages, 

 and by the mode of insertion of the appendages, which are 

 not branched. He says that the appendages or leaves 

 were rigid (as with other species of the genus). He con- 

 siders that the nearest analogy of this form is with certain 

 seaweeds of the family Dasycladeae, such as Acrogenia of 

 the Devonian and Acetabulifera of the Eocene. 



Barrois says that Oldhamia is related to several small 

 forms of Chondrites that appear in the earlier geological 

 epochs, and are characterized by a frond, erect, divided 

 into rounded branches more or less numerous, of which 

 the substance was probably stiff, and of a cartilagenous or 

 gelatinous nature. Such are several paleozoic Chondrites 

 described by Goeppert, the Chondritis fiahellai'is of Saporta 

 of the Upper Lias, and others. The regular branching of 

 the stems and the fan-lrke arrangement of the appendages 



