species in the Lower Silurian rocks of Canada, which were evidently 

 attached and not free. Most of the specimens have a well developed 

 pedicle. Some of the others, which exhibit no pedicle, evidently attached 

 themselves while young to some cylindrical body and grew around it. We 

 have several with the stalk of a crinoid passing quite through either in the 

 centre or a little on one side. Others are perforated through the centre 

 as if they had grown around some upright slender body, which has dis- 

 appeared during the natural process of fossilization. Those with the stalks 

 of crinoids passing through them could not have been free, and the others 

 with the central perforation appear to be of the same species. The struc- 

 ture and general form does not differ from those which exhibit perfect 

 evidence of a pedicle. I propose therefore to separate the species here 

 mentioned from Astylospongia, and arrange them under the name of 

 JEospongia. 



I shall place a new species from the Trenton limestone, corresponding 

 in form to Roemer's A. inciso-lobata in Astylospongia. 



EOSPONGIA ROEMERI. (N. Sp.) 



Description. Elongate, pyriform or club-shaped ; the internal structure 

 in polished sections shows numerous circular tubes, those in the central 

 part of the mass the largest. 



The best preserved specimen that I have observed is 5J inches in 

 length and 3 inches in diameter at two inches from the top. The 

 larger extremity is rounded, with a small depression 1 inch wide and 

 half an inch in depth in the centre. It tapers gradually from 3 inches to 

 a diameter of 1 J inch at the small end where it is broken off. The pores, 

 as shewn in a polished transverse section, are from 1 a line to 2 lines in 

 diameter. 



Dedicated to Dr. FERDINAND ROEMER. 



Locality and Formation Mingan Islands, Chazy limestone. 



Collectors. J. Richardson, Sir W. E. Logan. 



EOSPONGIA VARIANS. (N. Sp.) 



Description. This species is depressed turbinate, expanding from the 

 obtusely pointed pedicle to a width of from two to three inches, at a height 

 of from one to two and a-half inches. The upper margin is obtusely 

 rounded. The width of the cup is about one-third of the whole diameter, 

 and about a-half or three-fourths of an inch deep, rounded at the bottom, 

 and with a thick rounded margin. The greatest width of the species is in 

 general near the top, but in those which have grown around the stalk of a 



