270 



ASAPHUS CANALIS? (Conrad.) 



ISOTELUS CANALIS. (Conrad) M8. (Hall.) Pal. N. F., vol. 1, p. 25, pi. iv, figs. IT, 18, 19. 

 a b 



Fig. 255. 



Fig. 255. Jlsaphus canalis. a, the lower side of the hypostoma ; 6, the upper or inner 



side. 



Remarks. The specimen above figured is the hypostoma of a large 

 Asaphus, of a species that has a great vertical range in the rocks of 

 Newfoundland. No- entire specimens have been found, but fragments 

 occur in all the Divisions from F to M inclusive. The pygidium is char- 

 acterized by a wide concave margin all round, but in other respects has 

 the form of A. platycephalus. A pygidium resembling it occurs in the 

 Chazy limestone, both in Canada, and at the village of Chazy in the State 

 of New York. It is also found in the Calciferous formation at Mingan, 

 and in the Counties of Leeds and Grenville, in Canada West. Several 

 large, and nearly entire, individuals, have been collected in the Chazy 

 sandstone at L'Orignal, Aylmer, and on the Island of Montreal. The 

 specimens from all these localities agree so well with Prof. Hall's descrip- 

 tion and figure, above cited, of A. canalis (Conrad), that I have referred 

 them to that species provisionally. 



It will be observed that the above figures do not show the two wings 

 that project, one on each side, from the anterior extremity of the hypos- 

 toma of an Asaphus. A perfect specimen from Point Rich explains their 

 absence. They are very small, and situated on the upper side, from which 

 they project nearly at right angles to the plane of the hypostoma ; conse- 

 quently, in a view of the lower side (fig. 255, a), they cannot be seen. 

 Fig. 255, 6, shows the upper side, but in this specimen they are broken 



