RAYMOND: NOTES ON THE ONTOGENY OF PARADOXIDES. 239 
REMARKS. 
As may be seen by the following quotation, the specimens here 
separated as a new species have not escaped observation. Dr. Wal- 
cott (Loc. cit., p. 46), in discussing the broad and narrow forms of P. 
harlani says :—“ In the head the greatest variation is seen in the contour 
of the frontal margin, and the gradual development of the frontal 
limb and rim. On the smallest specimens the frontal limb is very 
short and more or less rounded. With the increase in size, the space 
between the glabella and the marginal rim increases in width, and the 
latter broadens and flattens out.” It is not the narrow form of P. 
harlant as described by Walcott and Grabau which I am separating 
as a new species, but the form with the narrow brim and raised, 
striated rim. Judging from the above quotation, this form bas been 
placed as the young of the narrow form of P. harlani. As has been 
shown under the description of P. harlana above, material recently 
collected shows that the young of P. harlani had a broad flat rimless 
brim, similar to that of the adult, so that the rimmed forms can not 
be referred to that species. 
CoMPARISON WITH OTHER SPECIES. 
Paradoxides haywardi is a much more normal type of Paradoxides 
than P. harlani, and it is therefore comparable to a far greater number 
of species. From P. harlanz itself, it differs, as has already been 
pointed out, in having an angular instead of a rounded frontal margin, 
and in having a narrow brim and thickened rim on the front of the 
cranidium, in the absence of the anterior pair of glabellar furrows, and 
probably in the wider furrows and narrower spines on the pleura of 
the thorax. It resembles P. eteminicus Matthew more closely than 
any other American form, but differs from that species in having 
shorter eyes, the lobes of which do not touch the glabella or neck ring, 
in lacking the anterior pair of glabellar furrows, and in having a wider 
‘groove separating the glabella from the rim. Most of these same dif- 
ferences and others obtain between P. abenacus Matthew, P. acadius 
Matthew, P. micmac Hartt, P. lamellatus Hartt, and P. haywardi. 
P. regina Matthew and P. bennetti Salter appear to have the wide 
margin of P. harlani; and of Billings’s two Newfoundland species, 
P. tenellus seems to be based on immature specimens, and P. decorus 
| is not well known. 
