380 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



Dicelloccphalus lodcnsis Whitfield, Chamberlin, 1883, Geol. Wisconsin, 

 Vol. I, p. 130, text figs. 16, i6a-b. (Illustrates nearly entire specimen of 

 dorsal shield.) 



The generic description of Saukia is based on this species; this 

 with the figures on plate 65 gives a sufficiently complete conception of 

 the species to furnish the student with the means for identifying and 

 comparing it with other species. It differs from the other species 

 referred to the genus by its strongly granulose surface and variations 

 in details of form of the parts of the cephalon and pygidium. 



Formation and locality. — Upper Cambrian : St. Lawrence forma- 

 tion; (85) at Prairie du Sac, Sauk County (Cooper Curtice, 1884) ; 

 (86) at Van Ness quarry, Gibraltar Blufif, Lodi, Columbia County 

 (L. C. Wooster, 1883 ; Cooper Curtice, 1884), both in Wisconsin. 



SAUKIA MARICA (Walcott) 



Plate 64, figs. 6, 6a 



Dicelloccphalus inarica Walcott, 1886, Monogr. U. S. Geol. Surv., Vol. 8, 

 p. 44, pi. 10, fig. 13. (Described as below.) 



Glabella and fixed cheeks subquadrate in outline, narrowing some- 

 what towards the front. Glabella subquadrangular and almost 

 squarely truncate in front, which is not quite as wide as the base ; 

 strongly convex, and marked by three pairs of furrows, the two 

 anterior pairs but slightly depressed and very short ; the posterior pair 

 extend obliquely inward one-third the distance across from each side, 

 and are united by a slight transverse furrow ; occipital ring strong 

 and elevated ; occipital furrow well defined ; dorsal furrows strongly 

 impressed ; fixed cheeks moderately convex, narrow in front, widen- 

 ing at the palpebral lobes, and sloping away rapidly in front, and less 

 so back of the eye lobes ; eye lobes narrow, semicircular, and situated 

 opposite the central portion of the glabella; frontal limb obsolete 

 except the round, thick, marginal rim just in advance of the glabella ; 

 the posterior limbs are broken away at a little distance from the dorsal 

 furrows. 



Surface as seen under a strong magnifying glass, with fine inoscu- 

 lating, flattened lines surrounding minute round or irregularly oval 

 spaces. 



Observations. — This species is represented by one specimen of the 

 cranidium. It resembles the cranidium of Saukia pyrene (pi. 6y, 

 fig. 18) and vS". fallax (pi. 67, fig. 21), but dififers in its frontal 

 border. It occurs in the closing epoch of the Cambrian in association 

 with a well-marked fauna (see locality 62, p. 361) . 



