NO. 3 CAMBRIAN TRILOBITES 207 



Formation and locality. — Upper Cambrian: (son, 30 o, 14V) 

 Weeks formation, in i& and ic of section (Walcott, Smithsonian 

 Misc. Coll., Vol. 53, 1908, p. 175) ; (soh, 3oi) Orr formation; near 

 base and about 275 feet from 2a of section (Idem, p. 177) ; north 

 side of Weeks Canyon, about 4 miles (6.4 km.) south of Marjum 

 Pass, House Range, Millard County, Utah. 



CREPICEPHALUS DIS, new species 



Plate 32, figs. I, la-c 



Crepicephaltis Walcott, 1908, Smithsonian Misc. Coll., Vol. 53, pp. 175, 176. 

 (Name listed in geological section.) 



This is the C. iowensis (pi. 29) representative in the Cordilleran 

 province. It has the same form of glabella except that it is a little 

 more conical or rounded in front ; the frontal limb is narrow^er, and 

 the occipital ring is narrower towards the ends when viewed from 

 above. The associated pygidia differ in outline of the postero- 

 lateral portions of the border, which in C. dis are prolonged into 

 short spines and in C. iozvensis into long, sharp spines. 



Crepicephaltis dis is associated with C. coria, but neither the cra- 

 nidium nor the pygidium is similar to that species. The pygidium 

 is much Hke that of C. camiro (pi. 32, fig. 2a) except that the axial 

 lobe is shorter and has three instead of five or six rings. 



Surface of test smooth to the unaided eye, and minutely pitted 

 and apparently punctate as seen by a strong lens. 



Formation and locality. — Upper Cambrian : (son, 30 o, 14V) Weeks 

 formation, in ih and ic of section (Walcott, Smithsonian Misc. 

 Coll., Vol. 53, 1908, p. 175) ; (30J) Orr formation; le of section 

 {Idem, p. 177) ; north side of Weeks Canyon, about 4 miles (6.4 

 km.) south of Marjum Pass, House Range, Millard County, Utah. 



CREPICEPHALUS IOWENSIS (Owen) 



Plate 29, figs. I, 2, 2a- f 

 Dikelocephalus ? iowensis Owen, 1852, Rept. Geo!. Surv. Wis., Iowa, Minn., 



P- 575. pl- I. fig- 4; pl- lA, fig. 13. (Describes and illustrates species.) 

 Conoccphalites iowensis (Owen) Hall, 1863, Sixteenth Ann. Rept. N. Y. 



State Cab. Nat. Hist., p. 162, pi. 7, figs. 29-33; pl. 8, figs. 10-12, 30. 



(Describes and illustrates species.) 

 Conocephalites iowensis (Owen) Shumard, 1863, Trans. Acad. Sci. St. 



Louis, Vol. 2, p. 102. (Refers to species and having found the head.) 

 Conocephalites iowensis (Owen) Hall, 1867, Trans. Albany Inst., Vol. 5, 



p. 149, pl. 7, figs. 29-33; pl- 3. figs. 10-12, 30. (Reprint of paper of 



1863.) 



