NO. 3 CAMBRIAN AND OZARKIAN TRILOBITES II3 



postero-lateral limbs join the glabella, and connecting them is a 

 shallow furrow which causes a slight up-turning of the occipital edge. 

 The free cheeks of ^. entella are larger than in 6^. zuoosteri. They are 

 not nearly so much thickened in front of the glabella, but have a 

 wide, striated doublure. The genal spine is long and slender. 



The pygidium assigned to S. entella also departs from that of the 

 genotype. It has no trace of an axial furrow, its position being marked 

 only by notches similar to those marking the position for the dorsal 

 furrow in the cranidium. The shape of the pygidium and the exis- 

 tence of a long spine agree with the same characters in .S. woosteri. 



Formation and locality. — -Ozarkian: (65W) Mons formation, id 

 of section. North side of Clearwater Canyon, two miles (3.2 km.) 

 from divide at head of canyon and about 21 miles (33.8 km.) in an 

 air line north 2° west of Lake Louise Station, on the Canadian Pacific 

 Railway, Alberta, Canada. ' » 



SYMPHYSURINA EUGENIA, new species 

 Plate 21, figs. 25-29, 31, 32 



Observations.- — ^This species agrees in all essential respects with 

 the genotype and is about of average size. All the available material 

 is more or less fragmentary. 



Cranidium usual size and shape and differs very little from that of 

 5. spicata Ulrich, being a little more scjuare across the front. Free 

 cheeks without genal spines. Spine on pygidium shorter than in 

 vS. spicata. 



Formation and locality. — Ozarkian: (65V) : Mons formation. 

 Same as Symphysiirina entella in le of section. 



SYMPHYSURINA SPICATA Ulrich (MSS.) 



Plate 21, fig-s. 12-18 



Ampyx ? Walcott, 1884, Pal. Eureka District, Monogr. U. S. Geol. Surv., 

 Vol. 8, pi. 12, fig. 19. (Pygidium only, not described.) 



Quotation from Dr. Ulrich's manuscript : 



" Trilobite small, the typical variety probably not exceeding 25 mm. 

 in length. Cranidium relatively a little longer than the average for 

 the genus, moderately convex, arching (in longitudinal direction) 

 uniformly from the posterior edge to within a fifth of the length from 

 the anterior edge where the profile straightens and finally becomes 

 concave as it passes through the hollow, frontal border ; sutural edges 

 diverging very slightly and almost straight in the first halves of their 

 courses forward from the eyes, then turning inward around the antero- 

 lateral angles which, therefore, are broadly rounded ; front part of 



