ADDITIONAL NOTES ON THE CAMBRIAN OF CAPE BRETON 
417 
the glabella. The glabella, though slightly marked elsewhere, is 
•marked off in front by a slope to the flattened margin. 
The thorax now has five joints, and the pleunv has grooves and 
-facets like the adult. 
The pygidium has about the same number of segment as in. the 
younger shield, but those of the neopygidium are less prominent than 
in the younger moult ; they are, however, still discernable on the side- 
lobes, as well as on the rachis. In this, while not agreeing with the 
genus Asaphellus, they recall many others of the Asaphidie. 
Note on the Young of Asaphellus Homfrayi. 
Since writing the above in regard to the young of Asaphellus 
Homfrayi the writer has consulted Dr. Callaway’s article on the 
fauna of the Shinton Shales,* and was at once struck with the resemb- 
lance between the youngest form here described, and Conophrys Salo- 
piensis, and it is clear that the latter is a later stage or development 
of the former. 
There is no question that in the Canadian form three rings, of the 
five that are strongly marked, are still a part of the pygidium; but if 
they were free rings there would be a remarkably close assimilation to 
Conophrys, the difference lieing only in the greater number of rings 
in the thorax of this genius. Looked upon as a developmental stage 
of Asaphellus this difference is to be expected, as our form is smaller 
than Conophrys Salopiensis. 
The differences in the headshield are also of a kind that naturally 
follow from the two being different stages of development. Dr. Calla- 
way shows the front lobe of the glabella as much more distinct than 
that of the Canadian form, though he speaks of it as being “ hardly dis- 
tinguishable from the front of the head in the Canadian form this 
lobe is barely discernable, except at the sides of the glabella. Again 
the speaks of the neck furrow being “deep,” whereas in the Canadian 
form it cannot be discerned, and the lateral furrows are fainter and 
more embryo-like. Conophrys Salopiensis therefore may very well 
stand as a developmental stage of A. Homfrayi^ somewhat , more 
.advanced than the youngest form ascribed to this species from the 
♦Quart. Jour. Geol. Soc. London, vol. xxxiii, p. 662, 
