77 



'there is a concave space all round. In the middle there is a longitudinal 

 roof-like ridge, from which radiate a number of grooves to the border. 

 Tiie general aspect is that of a small Chiton or Patella, flattened by pres. 

 sure. It is not probable, however, that they are allied to either of these 

 genera. 



Fig. 45. Aspidella terranovica, two specimens on a small slab of stone, slightly restored. 



Associated with these are numerous specimens of what appear to be 

 ArenicoUtcs spiralis, a fossil that occurs in a formation lying below the 

 primordial rocks in Sweden. These fossils were first discovered by 

 A. Murray, Esq., F.G.S., in 1866- Other specimens were collected by 

 Capt. Kerr, R.N., Mr. Howley and Mr. Robertson. 



They occur near St. Johns, in the Huronian. A more detailed descrip- 

 tion will be given hereafter. 



Stenotiieca pauper, (N. sp.) 



Description. — Shell small, conical, with the apex incurved, laterally 

 compressed. Aperture ovate, elongated in the plane in which the curva- 

 ture of the apex occurs. Surface with four or five small engirdling convex 

 ridges. Length of aperture about one and one-half lines ; width about 

 one line ; height of shell about one line. 



Occurs in the red limestone at Brigus, Conception Bay. 



In the Quar. Jour, Geol. Soc of May 1872, Mr. Hicks has described and 

 figured, under the name Stcnotheca cormicoijia, a small shell which is 

 evidently congeneric with this. To the same genus should perhaps be 

 referred the shell known as 3Ietoptoma rugosa of the Lower Potsdam ? of 

 New York. 



ScENELLA Reticulata. (N. gen. and sp.) 



Description. — Shell small, almost uniformly depressed, conical ; apex 

 central or nearly so ; an obscure carina extending from the apex down 

 one side to the margin. Aperture nearly circular, apex very slightly 

 incurved towards the side opposite the carina. Surface reticulated with 

 fihe radiating and engirdling striiTc.just visible to the naked eye. Diamc- 



