197 



rounded ; front margin gently convex ; dorsal furrows well defined to the 

 front ; neck-furrow most strongly impressed on each side of the middle ; 

 posterior glabellse-furrows oblique, situated behind the mid-length ; two 

 pairs of anterior furrows ; all the furrows very obscure. The anterior 

 margin of the head is thin, narrow, destitute of a rim, and turned upwards. 

 The eyes appear to be small, and situated on a hne drawn across the 

 glabella, a little behind the anterior third. They are distant from the 

 dorsal furrow about one-fourth the width of the glabella, and have a well 

 defined ocular ridge. 



Length of the best preserved glabella 7 hnes ; width at neck segment 

 5|- lines ; width at the front margin 4 lines ; width of the margin of the 

 head in front of the glabella 1 line ; distance of the eye from the side of 

 the glabella 1 J lines. 



The form of the glabella in this species is almost exactly the same as 

 that of D. Devinei, and yet I think the two are distinct, for the following 

 reasons : — 



One of the specimens of D. Devinei shows that the margin of the head 

 in front of the glabella has a width equal to one-half the whole length of 

 the glabella, whereas in this species it is only one-seventh. 



Locality and Formation. — Point L^vis, in limestone No. 1 ; Quebec 

 group. 



Collector.— H. 0. Weston. 



DiKBLOCBPHALTJS AFFINIS. (N. Sp.) 

 Fig. 183, a, b. 



Description. — Glabella oblong, sub-quadrate, length one-fifth greater 

 than the width ; sides straight and nearly parallel ; front angles rounded ; 

 front margin gently convex. The front margin of the head is gently 

 convex, and has a width equal to nearly one-third the length of the 

 glabella. It has a row of small punctures, at one-third its width from the 

 glabella, as there is in D. Oweni. There do not appear to be any 

 glabellar furrows. The glabella is very gently convex, and there does 

 not seem to be any marginal rim to the front of the head. 



The pygidium, found with it, is convex and has a broad obtusely conical 

 axis, one-third the whole width and two-thirds the whole length. Front 

 margin gently convex, and all behind the angles uniformly rounded. 

 Length two-thirds the width. Both axis and side lobes are nearly smooth, 

 but exhibit faint indications of segmentation. It is not at all certain that 

 this pvaidium belongs to the species. 



