326 .PHYSIOLOGICAL SERIES. 



call it " anterior ectosylvian." It is continued into a short 

 vertical sulcus the pseud osylvian. From the latter a 

 sulcus, which Krueg calls the " processus posterior of the 

 Sylvian fissure," leads backward toward the poster iorrhinal 

 fissure. It is the posterior ectosylvian sulcus of Holl. 



There is a depressed area between the rhinal fissure and 

 these three parts of the so-called ll Sylvian fissure." This is 

 the trigonum Sylvii (Holl) and it is continuous anteriorly 

 with the so-called " gyrus orbitnlis," i. e. } the narrow strip 

 of pallium between the orbital (presylvian) sulcus and the 

 rhinal fissure (fig. 188). 



Although the calcarine (splcnial) sulcus can be partly 

 seen on the dorsal surface, it is placed chiefly upon the 

 mesial surface, as in most mammals (fig. 189). The position 



Fig. 189. (x|.) 



SULC.INTERC. 



SULC.GEN. 



\ 

 SULC. ROST. 



of this sulcus in the Ungulata seems to be determined 

 largely by the size of the hemispheres. In the small 

 Chevrotain it is chiefly dorsal, in the larger Musk-Deor it 

 is on the dorso-mesial border, and in the larger Deer it is 

 mesial. 



There is a well-developed lateral sulcus pursuing a course 

 parallel to the posterior half of the suprasylvian sulcus, and 

 there are several short sulci behind and in front of it. 



There is a small genual sulcus above the anterior 

 extremity of the corpus callosum and a rostral sulcus in 

 front of it. 



The anterior extremity of the prolongation of tin- 

 calcarine (splenial) sulcus is upturned and may ronvspond 

 to the crucial Hilms. A small ansate sulcus given oft' from 

 the junction of tin- ronmary and .-uju a-\ l\ iau .-ulri |>r< 



