es 
PALAOZOIC ROCKS IN CANADA AND SCOTLAND. 375 
This is an abundant form, though perfect specimens are rarely met 
with. It varies greatly in size; the smaller examples are about 
1 line long, whilst the largest, as in the specimen figured, are 33 
lines in length and 14 wide. It may be distinguished from F. 
(Nereidavus) varians, Grinnell, by its truncated extremity and the 
median furrow and cavity. 
Kunicitus (NEREIDAVUS) VARIANS, Grinnell. (Pl. XVIII. figs. 2, 3, 5.) 
Nereidavus varians, Grinnell, American Journal of Science, Sept. 
1877, p. 229. 
Jaw elongated, curved, rounded in front, and convex, widest at 
about one third the length from the anterior end, and then gradually 
tapering to a point, the front portion sometimes curved upwards and 
inwards, the first tooth rounded, somewhat larger than the rest ; 
succeeding this are from two to five, blunted, rounded, upright teeth, 
and then aseries, varying in different specimens, of from nine to four- 
teen pointed teeth. These latter gradually diminish in size towards 
the posterior end, and are uniformly directed backwards. The 
dimensions of the specimens figured are as follows :—fig. 2, 23 lines 
long and 3 line wide; fig. 3, 2 lines long and about j line in width; 
fig. 5, 33 lines long and 7 line wide. Abundant. 
As the type specimen figured by Mr. Grinnell is imperfect, showing 
only the anterior portion of the jaw, I am unable to judge whether 
my examples are rightly referred to his species; but there is a very 
close resemblance between his fig. 1 (op. cit.) and my fig. 5, which 
leads me to believe that they are similar. These examples appear 
to me to correspond more with one of the toothed jaw-plates of 
Eunice (Leodice) antennata, Savigny, than with the jaws of Nereis, 
which in all the examples I have seen are widened at the posterior 
end for the muscular attanchment, whereas these examples all taper 
to a point. 
Eunicires contortus, Hinde. (Pl. XVIII. fig. 4.) 
Jaw elongated, very narrow, and tapering to a point, the anterior 
tooth prominent, nearly upright, not in plane with the rest, and fol- 
lowed by a uniform series of about seventeen pointed teeth, which 
are all directed backwards, parallel with each other. Length about 
13 line. 
“This form, besides being much smaller than Z£, varians, has also a 
more prominent anterior tooth, and the smaller teeth form a uniform 
series. Not unfrequent. 
Eunicires PERDENTATUS, Hinde. (Pl. XVIII. fig. 6.) 
Jaw extremely small, narrow, and gently curved; the anterior end 
elevated and bent inwards ; on this portion are two or three rounded 
teeth, which are followed by a series of about twenty very minute, 
subequal, acutely pointed teeth. 
The extremely small size, and the absence of a prominent anterior 
tooth, suffice to distinguish this from the preceding form. It also 
resembles 4. (Aulacadus) obliquus, Kichwald (see Pander’s Mono- 
