78 



of the surface is slightly gibbous, but perfectly smooth, except 

 where the raised axis crosses it to the margin of the depressed 

 band. 



Locality — This beautiful and well-preserved specimen was found 

 by Mr. Harrison at Randel Crag. 



Group C. No. 2. 



In general form this species is broadly oval, but the specimen is 

 so much weathered that its distinctive features are almost obliter- 

 ated. The oval disc and axis, however, are clearly defined. 

 Length three inches and four-tenths, and width two inches and • 

 seven-tenths. The axis is well-rounded; it measures one inch and 

 a tenth at the front part, and tapers to half an inch at the caudal 

 extremity, which is about two-tenths of an inch from the posterior 

 margin of the pygidium ; on the front portion it shows distinct 

 traces of seven segments. Axal furrows deeply cut and quite 

 straight, except the outward curve at the margin of the carapace. 

 The head appears to have been unusually small, measuring only 

 half an inch from the front segment, but in all probability the 

 latter may have belonged to the cephalic shield, and the remaining 

 six would be thoracic segments. The distinguishing features of 

 the pleurse and caudal shield cannot be made out. 



Locality — Randel Crag. From Mr. Harrison's cabinet. 



Group C. No. 3. 



This is the largest trilobite that has been found in the Skiduaw 

 Slate formation, but unfortunately it is in a very imperfect state ; 

 the pygidium, right pleurte, and a part of the cephalic shield are 

 broken off; when complete, it would be at least nine inches in 

 length, and five inches in width. The general surface of the body 

 is faintly rounded, cephalic shield almost semi-circular in shape, 

 glabella large, and apparently devoid of ornament, except a faintly- 

 arched furrow at the base ; axal furrows curve boldly outwards 

 from the base to the margin of the cephalic shield. The right 

 cheek has disappeared, but the left is clearly defined : it is about 

 one-fourth the size of the glabella, and in form resembles a gothic 



