552 KR. S, J. HICKSON OX 



from the apex of tlie branches, instead of upwards towards the 

 apex of the branch, as they are in most of the Primnoinse. 



In the specimen from British Columbia, the terminal branches 

 including the zooids are about 6 mm. in diameter and excluding 

 the zooids about 3 mm. in diameter. The zooids are quite 

 irregularly distributed on the branches, larger and smaller ones 

 being mixed, and they are all bent downwards towards the base 

 of the bj-aneh. The larger zooids are about 5 mm. in length by 

 about 1'5 mm. in diameter. 



The opercular scales are triangular in shape, with a very well- 

 marked keel passing along the adoral side from the apex towards 

 the base. These scales are 1'5 mm. in length (from apex to base) 

 and 0'6 mm. in breadth. Behind and partly overlapping the 



Text-figure 3. 





A single zooid of Frlmnoa tvllleyi. X 15 diam. 



opercular scales on the abaxial side there is a half circle of large 

 oblong scales TOS x 0-75 mm., and arranged very irregularly over 

 the rest of the abaxial side there are long narrow scales of v^arious 

 .sizes up to 1-8 mm. in length by 0-2 ram. in breadth (text-fig. 3). 

 Some of these elongated scales occur on the adaxial side of the 

 margin of the zooid overlapping the opercular scales, but the 

 greater part of this side of the zooid is naked. 



In Primnoa reseda and in Primnoa jmcifica thei'e is less 

 difference between the marginal scales and the other scales of the 

 abaxial side of the zooids, and in both these species the zooid is 

 more completely covered and protected by square or oblong 

 jseales. 



The new species differs from both the other two species, not 



