174 L. M. Larnbe — Fish Fauna of the Albert Shales. 



the pectorals. The caudal fin is heterocercal and deeply forked, 

 the body prolongation in the upper lobe tapering gradually. 

 The scales are rather coarsely sculptured. In the anterior 

 flank scales, figure 7, the sculpture consists of two or three 

 delicate but distinct well-defined ridges in the lower half of 

 the surface, parallel to the lower margin, with three to five 

 short, prominent ridges in the upper half of the scale ; these 

 latter are directed obliquely backward and downward in a 

 somew T hat divergent manner from a slightly raised but ill- 

 defined area confined to the upper, anterior portion of the 

 scale. The posterior edges of the flank scales are coarsely 

 toothed, three or four being the usual number of the denticu- 

 lations. In passing backward the surface ridges of the scales, 

 figure 8, are reduced in number as are also the denticulations 

 of the posterior margins, until posteriorly, in the small diamond- 

 shaped scales of the caudal body prolongation, all trace of 

 sculpture is lost and the surface of each scale is smooth. 

 Enlarged, ovoid, imbricating scales, with well-marked longi- 

 tudinal ridges, extend along the median line of the back, in a 

 single row, from the head to the commencement of the dorsal 

 fin, and from behind this fin to the caudal, on which they are 

 continued as large fulcra-like modifications decreasing in size 

 posteriorly. On the ventral surface similar enlarged scales 

 occur between the ventral and anal fins and between the latter 

 and the base of the caudal, where they give place to small fulcra 

 on the lower margin of the tail. Of the flank scales the largest 

 are those of the lateral line. 



Two specimens from Beliveau, IN. B., of w T hich one is the 

 type, and one specimen from Horton, N. S., constitute the type 

 material of this species. 



Canobius modulus has about the same length as C. ramsayi 

 Traquair but is not so deep. The scales are differently sculp- 

 tured and in this respect the species is distinct from all other 

 described ones of the genus. 



