iSqS.] Osborii, Evolution of the Amblypoda. Parti. 205 





-1 3 



= 



s'S 



JO ^ 



B-.S 



So 



E " 



is 



as C. lobiitus Co])e, which may be 

 considered as indeterminate types, 

 present exactly the C. aiiax measure- 

 ments (see Table, p. 198), and exhibit 

 an oblique hypolophid and depressed 

 entoconid 2 upon ni;,, as shown in 

 Fig. 16. This may be considered the 

 typical C. Iflbatus or C. anax third 

 lower molar. It is well shown in the 

 large jaw, No. 4333, and in the frag- 

 ment, No. 4305. 



A variation, No. 266, in molars of 

 the 6'. loluitus size is ])aralleled by a 

 variation. No. 4239, in molars of the 

 C. ductus size, as represented in Fig. 

 16, in which the three cusps form a 

 posterior triangle, as also in C. citspi- 

 datns (No. 4324). If these are not 

 variations they represent three dis- 

 tinct species, which is possible but 

 not proljable. 



Synonym. — The skeleton defined as 

 C.pacliypus by Cope (No. 4335) un- 

 doubtedly belongs here. The astra- 

 galus of C. pachypus and of another 

 specimen (No. 2870) exhibit no astra- 

 galar foramina, and show a wider in- 

 terval on the front face of the astra- 

 galus between the tibial and navicular 

 facets than we find in C. testis. 



The massive male skull in our col- 

 lection (No. 2866) is most interesting 

 in its progressive development of the 

 parietal horn thickenings, parallel 

 with those of Uintatheriuin. Its 

 geological level, however, according 

 to Wortman, is below that of C. testis, 

 an observation very difficult to recon- 

 ^; cile with the more advanced evolution 

 n of its skull and molar teeth. 



