206 



the head, convex, sometimes flattened between the eyes, thence arched 

 down to the front ; sides in the posterior two-thirds or three-fourths 

 nearly parallel, slightly converging backwards ; front somewhat angularly 

 rounded ; neck furrow narrow extending all across and continued on the 

 cheek beyond the eyes ; neck segment depressed convex, widest in the 

 middle. Eyes reniform, close to the side of the glabella, a little more 

 than one-third the whole length of the head ; their posterior angles about 

 one-fifth their own length from the neck furrow. Surface of the glabella 

 smooth, cheeks sometimes tuberculated. 



Length of a specimen 4 lines ; width across the neck furrow 6 lines ; 

 length of the glabella 3| lines ; width of the same between the anterior 

 angle of the eyes 2i lines ; width at neck furrow 2 lines ; length of pos- 

 terior spines about 2 lines ; length of the eye 1J line. 



Locality and Formation. Near St. Antoine above Quebec, in a 

 boulder with Subulites Psyche : Quebec group. 



Collector. J. Richardson. 



CHEIRURUS SOLITARIUS. (N. sp.) 



Description. This species is founded on a single small specimen con- 

 sisting of the head and seven segments of the thorax, the whole being 

 only three lines in length. Head convex, semi-circular, the posterior 

 angles with short spines ; glabella strongly convex, abruptly tumid in 

 front, greatest elevation a little behind the mid-length ; front rounded ; 

 sides straight for two-thirds the length, sub-parallel, slightly converging 

 backwards ; anterior angles broadly rounded ; neck furrow all across ; 

 two glabellar furrows on each side dividing all of the glabella in front of 

 the neck furrow into three nearly equal parts ; the anterior furrows nearly 

 at right angles ; the posterior entering obliquely backwards and distinct 

 one-third across, and then obscurely marked backwards to the neck fur- 

 row ; all the furrows extending about one-third across. Eyes reniform, 

 their length equal to half the width of the glabella, their posterior angles 

 about half their own length from the neck furrow and about the same dis- 

 tance from the side of the glabella. The cheeks are rather small ; the 

 terminal spines appear to be two-thirds the length of the head ; the gla- 

 bella is full one third the width of the head, and extends the whole length 

 of it, and even seems to overhang the margin. The axis of the thorax 

 seems to be wider than the side lobes, but the latter are obscurely pre- 

 served in the specimen. 



Length of the head 1J line ; width at the neck furrow 3 lines. 



Locality and Formation. Near St. Antoine, above Quebec in a 

 boulder with Subulites Psyche : Quebec group. 



Collector. J. Richardson. 



