NO. 3 CAMBRIAN TRILOBITES 227 



Genus TSINANIA Walcott 



Tsinania Walcott, 1914, Smithsonian Misc. Coll., Vol. 64, p. 43. (Genus 

 described.) 



Genotype. — Ilhcniirus caucus (Walcott) [Cambrian Faunas of 

 China, Carnegie Inst, of Washington, Pub. No. 54, 1913, p. 222, 

 pi. 23, fig. 3]. 



TSINANIA CLEORA Walcott 



Plate 36, figs. 9, ga-c 

 Tsinania cleora Walcott, 1914, Smithsonian Misc. Coll., Vol. 64, p. 43. 

 (Name mentioned in text.) 



The cranidium of T. cleora is much like that of T. canens. It 

 differs in being longer in proportion to the width. The associated 

 free cheek (fig. ga) is large, broad, and gently convex to the outer 

 margin. An associated thoracic segment has the pleural lobe with a 

 very faint longitudinal furrow. The associated pygidium is trans- 

 verse, about twice as wide as long, and marked by a low axial lobe 

 that becomes very inconspicuous toward the posterior margin of the 

 pygidum. Only a slight trace of transverse furrows can be detected 

 on the matrix of the axial lobe. The pleural lobes are about twice 

 as broad as the axial lobe. The test is thick and apparently smooth 

 on its outer surface. 



The largest cranidium has a length of 14 mm. An associated 

 pygidium has the same length with a width of 28 mm. 



The pygidium of T. cleora is proportionally shorter than that of 

 Tsinania canens,"^ but the general character is the same in the two 

 species and quite unlike the pygidium of Illccnuriis quadratus? 



Numerous specimens of the cranidium and pygidium are associ- 

 ated, and the only other trilobitic remains are those of small species 

 of Agraulos and Solenopleura-Vike forms. The associated brachio- 

 pods are Schizambon typicalis Walcott ? and Eoorthis desmopleura 

 (Meek). 



This species is referred to the Upper Cambrian, but it may belong 

 to a lower Ozarkian fauna that has not yet been well determined and 

 probably will not be until the various faunal horizons of the lower 

 Pogonip limestones have been studied in the field. 



Formation and locality. — Upper Cambrian: (30W) Notch Peak 

 formation; drift bowlder of limestone supposed to have come from 



* Cambrian Faunas of China, Carnegie Inst, of Washington, Pub. No. 54, 

 1913, p. 222, pi. 23, fig. 3. 

 - i6th Ann. Kept. New York State Cab. Nat. Hist., 1863, pi. 7, fig. 56. 



