l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



of the posterior end of the axis. Beyond this elevation the border 

 appears concave upward in posterior view, while the border furrow 

 widens and the border becomes almost flat medially. Doublure wide, 

 sloping but slightly inward and forming an almost vertical face. The 

 edge of the doublure does not partake of the downward curve of the 

 posterior border, hence the doublure is much narrower in its poste- 

 riormost portion. Doublure with irregular terrace lines and smooth 

 margin. Upper surface of cephalon and pygidium perfectly smooth. 

 Length of largest pygidium 1 1 mm. 



Occurrence. — Collections cs-4 and USGS 4216, North Chatham. 



Ty/>^.f.— Holotype : U.S.N.M. 145995. Paratypes: U.S.N.M. 

 145996-7. 



BOLBOPARIA Rasetti, new genus 



Description. — Cephalon with strong relief. Glabella well tapered, 

 pointed in front, highest posteriorly where it extends into an upright 

 spine. Lateral furrows short, of generalized pattern. Occipital fur- 

 row distinct, occipital ring short (sag.) and simple. Cheeks as a 

 whole forming a subquadrate area in dorsal view, rising from a low 

 posterior part to their highest point near the anterolateral angles, 

 here bulging and overhanging the lateral border. The relatively long 

 (sag.) preglabellar field is a broad depression separating the bulging 

 cheeks. Anterior portion of border expanded ; border narrowest later- 

 ally under the bulge of the cheeks, widening again toward the 

 genal angle, extended into a pair of small, lateral spines and near the 

 genal angle carrying one or more pairs of tubercles. In front of the 

 genal angle the lateral border furrow merges with the posterior bor- 

 der furrow, at considerable distance from cephalic margin. Posterior 

 border furrow directed obliquely outward and forward from the 

 axial furrow, sharply turning outward after merging with the lateral 

 border furrow, and reaching the lateral cephalic margin well in 

 advance of the genal angle which bears a small spine. 



Pygidium semielliptical, strongly convex transversely. Axis well 

 defined, long, with numerous rings, the second bearing a large spine. 

 Pleural regions un furrowed ; border narrow, extended into minute, 

 downward-directed spines. Surface of test densely granulate in the 

 three known species. 



Type species. — Bolboparia superba Rasetti, new species. 



Occurrence. — Later Lower Cambrian of New York and Quebec. 



Discussion. — This is probably the most distinctive of all the new 

 genera of Eodiscidae described herein. The short, downsloping 



