NO. 3 CAMBRIAN AND OZARKIAN TRILOBITES lOI 



rim. A row of deep pits, somewhat irregularly spaced, occur in the 

 frontal furrow immediately back of the frontal rim. 



Free cheeks large, extending into a strong and long genal spine. 

 Their shape is somewhat peculiar due to the unusual direction taken 

 by the facial suture. A wide doublure extends from the genal angles 

 forward, maintaining practically an even width from a point anterior 

 to the occipital furrow to the center of the head. Thus far none of 

 the specimens has permitted the determination as to whether this 

 doublure is continuous and uninterrupted across the front of the 

 cephalon, or whether there is a median suture, or finally whether 

 there is an epistoma. As now known, specimens suggest a continuous 

 doublure. The pleurse near the front of the thorax are long, to 

 accord with the wide cranidium. They have a rather deep, narrow 

 pleural furrow, that has a slightly oblique direction, but yet approxi- 

 mately bisecting the pleurse and extending out to about the point 

 where the pleura begins to bend backward. The pleurre near the 

 posterior end are shorter in a transverse direction, with " wider 

 furrows, which bend backward with the pleura. The pleurae here are 

 as long as those in the anterior portion of the thorax, but bend 

 backward much sooner and are extended into a long slender spine. 

 The posterior pleurae must have enveloped the pygidium. 



Pygidium large and flat, with a definite, large, high axis. The 

 axis consists of from four or five to seven or more rings. The axial 

 furrows do not pass straight across but are as illustrated in figure 4. 

 The axis proper terminates some distance from the posterior edge, 

 dropping steeply off to the flat border, but with a median ridge 

 extending to the posterior edge, such as would be made by pinching 

 the axis with the fingers if it were made of some plastic material. 

 There are two definite pleurse in the tail outside of the flat areas, 

 which lie on either side of the axis and which vary in relative size 

 in the different species and in some, one or more additional pleurse, 

 differentiated by additional shallow furrows, may be distinguished. 

 The outer pleurse always extend beyond the border into sharp spines. 

 They are unfurrowed and the interpleural furrows are characterized 

 by their wai^y course. 



Derivation of name. — Named in honor of Conrad Kain, Swiss 

 guide and explorer of the Canadian Rockies. 



Genotype. — Hungaia billingsi Walcott. 



Range. — Ozarkian : Cordilleran area of Canada and the United 

 States, Province of Quebec at Point Levis and possibly Vermont in 

 Champlain Valley. 



