NO. 13 DIKELOCEPHALUS AND OTHER GFNERA 373 



DIKELOCEPHALUS VANHORNEI, new species 

 Plate 62, figs. 1-3 



This is a fine, large species of which we have for study the 

 cranidium thoracic segments, and pygidium. The cranidium is much 

 Hke that of D. inhinesoicnsis. It differs in having a proportionaUy 

 shorter glabella and wider fixed cheeks. The thoracic segments are 

 of the same type, but the pygidium is quite unlike that of D. tninnc- 

 sotensis. It is more transverse and has a larger axial lobe and a 

 smoother margin unbroken by spines. 



The type specimen of the cranidium (fig. i) has a length of 5.5 cm. 

 and an associated pygidium (fig. 3) has a length of 4.6 cm. and width 

 of 9.8 cm. 



The specimens occur as casts in a fine-grained, yellowish gray, shaly 

 sandstone and show only a few traces of a roughened surface on the 

 cranidium, and of fine raised, irregular lines on the flattened borders 

 of the pygidium. 



The specific name is given in recognition of the early work of Sir 

 William Van Home, who, as a young man, formed a collection of 

 fossils in Wisconsin, which he subsequently presented to the Museum 

 of McGill University, Montreal, Canada. 



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

 mation ; (346d) railroad dam at Hoka, Houston County, Minnesota. 

 Type specimens in Walker Museum, University of Chicago. Pal. 

 Coll. No. 14393. 



Plastotype No. 346d, U. S. Nat. Mus., Cat. No. 58608. 



While the above was in galley proof I received from Mr. W. A. 

 Finkelnburg, of Winona, Minnesota, specimens of the pygidium of 

 this species which were found in the bluffs near Winona. 



Genus SAUKIA, new genus 



General form elongate oval ; moderately convex. Cephalon trans- 

 versely semi-ovate with genal angles extended backward in strong 

 spines. Axial and pleural lobes strongly outlined. Marginal border 

 slightly rounded or nearly flat and merging into genal spines ; poste- 

 rior margin with a narrow, rounded, well-defined rim ; occipital ring 

 strong, nearly transverse. 



Glabella subquadrangular ; usually narrowing opposite the palpe- 

 bral lobes by slight incurving of its sides ; frontal margin broadly 

 rounded ; occipital furrow strongly defined ; posterior glabellar fur- 

 row strong, second furrow less pronounced than the first, and not con- 



