312 ME. i\ ATTHEY OX ANTHEACUSi TEXTS EUSSELLl. 



parietals. Their anterior and outer borders form one inch and 

 six-tenths of the posterior inner borders of the orbital vacuities, 

 including the posterior marginal prominence above mentioned. 

 They are bounded externally by the postorbitals and a small 

 portion of the supratemporals, and behind by the squamous bones. 



The squamous, of an irregularly square form, somewhat con- 

 cave internally and convex externally, are bounded internally 

 by the parietals, anteriorly by the postfrontals, externally by 

 the supratemporals, and posteriorly by the epiotics and a small 

 portion of the so-called supraoccipitals. Their posterior outer 

 angles contribute the curved inner border of the channels lead- 

 ing to the internal ears. 



The postorbitals are also of a somewhat irregularly square out- 

 line, and their anterior borders form one inch of the posterior 

 and outer concave margins of the orbital vacuities. They are 

 united internally to the postfrontals, externally to the jugals, 

 and behind to the supratemporals. 



The jugals form large irregular triangles, the bases of which 

 lie along the maxilla, the truncated apices supplying about an 

 inch of the outer margins of the orbital vacuities, the posterior 

 angles being cut off by the quadrate-jugals. They are seven 

 inches and a half in length, articulating anteriorly and internally 

 with the lacrymals and prefrontals, internally and posteriorly 

 with the postorbitals, the supratemporals, and, lastly, with the 

 quadrate- jugal bones. 



The supratemporals, of irregularly elongated form, lying ob- 

 liquely between the jugal and quadrate bones, and with them 

 constituting a good part of the lateral extensions of the cranium, 

 articulate anteriorly and internally with the postorbitals, exter- 

 nally with the jugals and quadrate-jugals ; posteriorly they over- 

 lap and articulate with the quadrates, and on their inner sides 

 join, first, the postfrontals, and afterwards the squamous. It 

 may be noticed that, although the matrix is entirely cleared 

 away from both the upper and under surfaces of these bones, 

 there is no indication of a supratemporal foramen, which is said 

 by Professor Huxley to exist. 



The quadrate-jugals, of somewhat rhomboidal outline, lie on 



