NO. 13 



DIKELOCEPHALUS AND OTHER GENERA 



383 



SAUKIA RUSTICA, new species 

 Text figures 18-20 



The cranidium of this species is much Hke that of Saukia lodcnsis 

 (pi. 65). It differs in its proportionally larger palpebral lobes, nar- 

 rower glabella, and exterior surface of the test. The test of 6". 

 lodensis is covered with rather large, rounded pustules, and that of 

 S. rustica with fine inosculating, irregular ridges that give it a 

 roughened but not a pustulose appearance. The largest cranidium 

 has a length of 7 mm. Small specimens 2 to 6 mm. in length show 

 a narrowing of the glabella toward the rounded front. 



The associated pygidium has a smaller axial lobe than that of 5'. 

 lodensis. 



19a 



Saukia rustica, new species 



Figs. 18, i8a. (X 4-) Type specimen of cranidium and side outline. U. S. 



National Museum, Catalogue No. 60678. 

 Figs. 19, 19a. (X 2.) Pygidium associated with fig. 18. U. S. National 



Museum, Catalogue No. 6067Q. 

 Fig. 20. (X 6.) Small cranidium. U. S. National Museum, Catalogue No. 



60680. 



The associated pygidium is much like that of Saukia fallax (pi. 67, 

 fig. 21), and the cranidium is of the same general character. 



Eoorthis zvichitaensis Walcott and Illccnunis sp. undt. are asso- 

 ciated with S. rustica. 



Formation and locality. — Upper Cambrian: (i2J: 50 feet below 

 i2g) Arbuckle limestone (lower part) ; Wichita Mountains, south 

 side about 8 miles ( 12.8 km.) w^est of Fort Sill and in a small hill 2 

 miles (3.2 km.) southwest of Signal Mountain, Comanche County, 

 Oklahoma. Fossil horizon No. 5 of E. O. Ulrich, 50 feet from base 

 of hill. Collected October 9, 1901. 



