96 



same distance from the side of the glabella. Neck furrow extending all 

 across the base of the glabella. The facial suture in its course in front of 

 the eye at first curves a little outwards and then forwards, cutting the an- 

 terior margin of the head on a line drawn parallel with the longitudinal 

 axis of the body, a little outside of the eye. Surface smooth. 



Length of head of largest specimen seen, about 2| lines. Length of 

 glabella, 2| lines. Width of head, 5|- lines. Diameter of the eye, | of a 

 line. 



The posterior angles and margin of the head are not preserved. 



This species closely resembles IT. Umbatus (Angelin), but that species 

 has the anterior angles of the glabella broadly, instead of acutely rounded. 



Locality/ and Formation. — Point L^vis ; in the upper part of limestone 

 No. 2, Quebec group. 



Collector. — J. Richardson. 



4. — New jSpecies of Fossils from different parts of the Lower, Middle 

 and Upper Silurian Rocks of Canada. 



ScoLiTHus Canadensis. (N. sp.) 



Description. — This species consists of numerous cylindrical or irre- 

 gularly prismatic stems, (or rather the cavities in the rock once occupied 

 by such stems,) from one to two Unes in diameter, and from one to six 

 inches in length, and either straight, or more or less curved. In some 

 specimens several of the stems are in contact with each other, and when 

 this is the case and the stems have an angular shape they very much 

 resemble the coral Tetradium. The larger stems are more often straight 

 than the smaller. The true Scolithas linearis is generally larger, and the 

 stems straight and parallel with each other. I have seen no specimens of 

 that species in our Canadian rocks, although it does occur in the lowest red 

 sandstone in Labrador, on the north shore of the straits of Belle Isle ; to 

 which place our survey has extended. In the Canadian species the indi- 

 viduals are usually irregularly scattered through the rock, lying in all 

 directions. 



Locality and Formation. — Townships of Landsdo^vne and Bastard, Ste. 

 Genevieve Island, near Ste. Anne, Bcauharnois, and at various other 

 localities in the upper part of the Potsdam formation. I have also col- 

 lected this species on the east side of Snake Mountain, in Vermont. 



Collectors. — Sir W. E. Logan, A. Murray, J. Richardson, R. Bell, E. 

 Bilhngs. 



