F. R. 0. Reed—On a New Species of Cyclus. 65 
spherical, but the posterior end is slightly more elevated and slopes 
more rapidly and steeply than the anterior, in this respect agreeing 
with C. Harknessi. 
The raised “dorsal line” starts from the hinder border of the 
buckler and runs up the centre of the posterior surface as a narrow, 
somewhat indistinct ridge. Its upper extremity is much thickened 
and rises sharply into a pointed tubercular eminence forming the 
highest part of a crest elongated in an antero-posterior direction 
which rests upon and like a half ring encircles (at a distance of about 
two lines from the posterior margin of the buckler) the point of origin 
of the arms of a large fork-shaped ridge. This conspicuous ridge has 
the shape of a U: its arms diverging strongly at first and then 
becoming sub-parallel. The length of the fork is a little over one line 
and the tips of the arms are the same distance apart. The ridge 
has a rounded granulated surface, and appears to be homologous 
with the upper row of tubercles which are separated from the ribs 
by the upper furrow, as shown in Dr. Woodward’s description and 
fizure of C. Harknessi; and this U-shaped ridge may therefore 
probably be considered to be the result of the fusion of these 
tubercles. I term it here for convenience ‘“‘the outer fork.” Two 
faintly indicated ridges, arising from the anterior end of the 
‘tubercular eminence above described, run up the inside of the 
stout arms of this outer fork of fused tubercles: at their free 
‘extremities these faint ridges curve outwards so as to end in the 
inner and posterior pair of cervical lobes. This pair of faint ridges 
evidently corresponds to the Y-shaped “cervical ridge” described 
by Dr. Woodward in C. Harknessi, but will be termed here to avoid 
confusion the “inner fork.” 
Cyclus, sp. nov. ? (ex Woodwardian Museum) Carboniferous Limestone, Settle, 
Yorkshire. Magnified ? nat. size. 
On the outer side of the arms of the large outer fork is a shallow 
groove almost as wide as the arms of this fork, and it is bordered on 
its outer side by a row of small tubercles which are more or less 
fused into a continuous ridge over the two anterior pairs of ribs, 
but are separate and distinct over the following four pairs; there is 
no tubercle visible over the last and 7th pair of ribs. In the figure 
of C. Harknessi all the tubercles are distinct. This broad upper 
groove would correspond with the upper furrow in C. Harknessi, 
but its greater width and more pronounced character are noticeable. 
Below this row of small, partly-fused tubercles, and parallel to it, 
is a much shallower and narrower depression, from which the seven 
DECADE III.—VOL. X.—NO. II. 5 
