100 



FOSSIL MEDUSA. 



Genus MEDUSICHNITES Matthew. 



In an article on "Illustrations of the Fauna of the St. John Group, 

 No. V," Mr. G. F. Matthew reprints the description of Mednsites princeps, 

 M. radiata, and M. costata, as given by Linnarsson. He also describes, 

 under the generic name Medusichnites, 1 what he considers to be trails and 

 imprints of tentacles of medusa?. Five forms are figured. 



Through the courtesy of Mr. Matthew, I have been enabled to examine 

 the original specimens, and I find that, with possibly the exception of fig. 1 

 of his PL XIII, all of the varieties of Medusichnites may be referred to 



Fig. 26. —Hfedusites ( ?) latilobatus. Enlarged section of a slice cut from a typical specimen of this species. 



markings of inorganic origin. I have seen large surfaces of Lower Cam- 

 brian shale in Rensselaer County, New York, covered with markings like 

 those shown by fig. 4 of PI. XII and fig. 1 of PI. XIII. These were 

 studied in connection with the investigation of medusadike trails, and the 

 conclusion was reached that they could not have had such an origin. 



In order that the student may have the means of comparison with 

 Eophyton, etc, I have introduced photographs (on PI. XLVI) of some of 

 the typical specimens described by Mr. Matthew. 



1 Trans. Royal Soc. Canada, Vol. VIII, 1891, Sec. IV, pp. 143-146. 



