280 PHYSIOLOGICAL SERIES. 



Arctoid families, in winch it attains its greatest develop- 

 ment, and is found not only in the larger memhers hut aU> 

 in many bruins of small animals (ride supra). 



The great complications produced in the area behind the 

 crucial sulcus by the development of "ansate" and " com 

 pensatory ansate " sulci are shown in the drawings (figs. 1 ."> 1 

 & 155). 



The broad gyrus which separates the lateral sulcus from 

 the interhemispheral cleft is subdivided by a very deep 

 entolateral sulcus, from which numerous offshoot> an- given 

 off both on the mesial and lateral aspects (fig. 155). 



The broad vertical gyrus between the postlateral sulcus 

 and the caudal margin of the hemisphere is complicated by 

 a series of three vertical sulci which are arranged in an 

 imbricate manner. For convenience of reference I shall 

 call them " paracandal" (fig. 154). 



The calcarine sulcus (fig. 156) is exceedingly deep. It 

 joins the intercalary sulcus at an acute angle. The latter 

 extends forward for a relatively short distance and ends in 

 a shallow vertical sulcus behind the crucial. Between the 

 intercalary and crucial sulci there is a small but deep 

 sulcus, which for convenience of reference may be called 

 " vertical." This crosses on to the dorsal surface and 

 there bifurcates (figs. 155 & 156). 



From the angle of junction of the calcarine and inter- 

 calary sulci two short, deep, posterior branches are given 

 off (fig. 156). 



On the extreme caudal edge of the moial surface there 

 is a deep sulcus parallel to and coextensive with til:- cal- 

 carine. It may be called the "paracalcarino " sulcus 

 (fig. 150). 



The lower extremity of the calcarine sulcus becoi 

 freely continuous (in this individual >peciim -n) with a 

 snlcus which begins (fig. 156) opposite the lower exnvmity 

 of the hippocampus, and proceeds as a deep cleft aero--; the 

 ventral surface of the hemisphere (fig. 157) ju-t In-hind the 

 natiform eminence of the pyrilorm lobe and the caudal 

 extremity of the posterior rhinal fissure. Although >mall 

 representatives of such a sulcus may occur among other 

 Carnivores, this fully-developed form is so peculiar to the 



