388 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



The species is known only by the cranidium and fragments of asso- 

 ciated pygidium that may belong to it. The cranidium differs from 

 that of Satikia lodensis (pi. 65) in having a narrowing of the glabella 

 from base to front and in its frontal limb and rim. With the speci- 

 mens available for study the impression is that we may be dealing 

 with a form more closely allied to Conokephalina Brogger than to 

 Saiikia. It differs from Conokephalina in the apparent direction of 

 the facial sutures through the frontal rim of the cephalon ; the form 

 of the frontal limb and rim also differ in detail from those of Cono- 

 kephalina. If the associated pygidium (fig. 3) belongs with the 

 cranidia (figs, i, 2) the provisional reference of the species to the 

 Dikelocephalinae is probably correct. 



The largest cranidium in the collection has a length of 21 mm. 



Formation and locality. — Upper Cambrian : Franconia formation ; 

 Green-sand horizon ; (S^^) below the " fifth trilobite bed " of Owen, 

 at Trempealeau, Trempealeau County (Chas. Schuchert, 1893), and 

 (83b) Bluff Siding, Buffalo County (Collection of W. A. Finkeln- 

 burg, Winona, Minnesota), both in Wisconsin. 



(99) Minneiska (Miniska), on Mississippi River, near the line 

 between Wabasha and Winona Counties, Minnesota (Cooper Curtice, 

 1884). 



Genus CALVINELLA, new genus 



Calvinella is founded on the cranidium of Dikelocephalus spiniger 

 Hall and associated free cheeks, thoracic segments, and pygidium. 



The cranidium (pi. 68, figs. 11, 13, 15) has the same general form 

 . as that of Saitkia leucosia (pi. 67, figs. 14, 16) and, in addition, a 

 strong occipital spine. The associated pygidium (pi. 68, figs. 18, 19) 

 differs from the Saukia leucosia group of species (pi. Gy, figs. 3, 12, 

 13, 17, 20) in having a broad flattened border comparable with that 

 of the pygidium of Dikelocephalus (pi. 60, figs. 6, 7; pi. 63, fig. 

 6), but the cranidium of Calvinella is quite unlike that of Dikelo- 

 cephalus. Further comparisons and remarks are given under obser- 

 vations on the family Dikelocephalinge (p. 362). 



Calvinella has a marked resemblance to some species referred to 

 Anomocare from the Middle Cambrian. The type species of Anomo- 

 care, A. Iccve Angelin ^ has nearly the same form of glabella and pal- 

 pebral lobes, but the frontal limb is dissimilar. The pygidium is 

 essentially of the same character in the two genera. 



The outer surface of all of the species of the genus is strongly 

 granulose on the glabella, free cheeks, parts of the thoracic segments 



^ Research in China, Vol. 3, Carnegie Institution of Washington, Pub. No. 

 54, 1913, The Cambrian Faunas of China, p. 264, pi. 18, figs, i, lb. 



