48 ROYAL SOCIETY OF CANADA 



onl}' the posterior furrow is traceable, and this is faint ; the occipital 

 furrow, however, is deep and broad. In the Swedish species two furrows 

 are indicated at the margins of the glabella. 



Dr. Koeminger's figure does not do justice to the size and prominence 

 of the fixed cheeks, which are quite tumid, and give the head, when 

 partly buried in the matrix, the appearance of a Trinucleus which has 

 been deprived of the decorated border. 



I judge from the form of the posterior marginal fold that the pleuraî 

 are strongly genicuhited ; with their deep furrows as described by Dr. 

 Roemingcr, they would resemble those of Solenopleura. The rachis of 

 the thorax is probably high and narrow. 



An example of a pygidium which appears to belong to this species 

 has one heavy furrow on the side lobe and two sharp narrow ones ; the 

 rachis is as described by Dr. Roeminger. 



Sculpture. — The thick test of this little species is covered with a 

 minute granulation. 



Size. — I have found no example larger than that figured by Dr. 

 Roeminger, though several smaller, they ai'e recognizable by the trilobate 

 appearance of the middle piece of the head, as described above. 



This species is distinguished from the Swedish one by the less pro- 

 minent, but broader front of the glabella. Judging from the form of the 

 Canadian species I would suppose that the second curve in the margin of 

 the suturai line of the middle piece of the head in the Swedish species 

 represents the eye-lobe. 



It is evident that Mr. Walcott is in error in his identification of this 

 species in the Mount Stephen material sent him by Dr. Roeminger. It 

 did not grow to anything like the size indicated by the former author, 

 which approaches nearly the full dimensions of Dorypyge Dawsoni. 

 Neither does this species have " fine irregular elevated stria» on the 

 glabella, but D. Dawsoni has. The young of D. Dawsoni with its rigid, 

 smooth glabella, somewhat broadened in front, might be mistaken for 

 this species, but the glabella is always more quadrate. 



Among the fossils of the Prospect Mountain limestone is one, which 

 by its size and general contour, approaches this species. This is the 

 0(jygia (?) problematic a. The dorsal suture is said to be that of Ogygia 

 and Asaphus, ho that although the anterior extension is not shown in the 

 figure it would be like Corynexochus Roemingeri. The dorsal furrows are 

 said to be shallow, in which respect they differ from the Mount Stephen 

 fossil. Shallow glabellar furrows are spoken of, but none such are shown 

 in the figure. 



