216 MISS K. F. LANDER ON THE 



supero-mesial margin. In front of this, lyi'^^ mainly on the 

 mesial aspect, is an oblique straight sulcus, 25 mm. in length. 



The rostral sulci are well marked ; in front of the cruciate-like 

 sulcus lies an H-shaped sulcus, and parallel with the anterior 

 margin of the biain runs a curved sulcus 30 mm, long and 5 mm. 

 deep. 



Stdci suhcinguli are represented by a longitudinal sulcus, 

 broken in the middle, placed between the intercalary svilcus and 

 the corpus callosum. The anterior part, 25 mm. long, curves 

 over the genu and bifurcates widely, the lower limb continuing 

 the curve, the upper running upwards between the two genual 

 sulci. Behind the splenium lies a vertical sulcus which is a 

 branch of the calcarine. This latter is 28 mm. long and 10 mm. 

 deep. The intercalary is 15 mm. deep at its commencement; 

 it arises from the calcarinfe about the mid-point of the latter. 



The rhinal fissure is well marked posteriorly ; in its depths is 

 a good deal of buried cortex. It turns round the occipital jaole 

 and runs up neai-ly to the posterior end of the calcarine. The 

 hippocampal convolution is 5 mm. broad anteriorly and below 

 the " Sylvian " fissure expands into a broad triangular mass, 

 40 mm. along the base and 25 mm. from, base to apex. Near its 

 posterior angle this is marked by a horizontal sulcus 10 mm. long. 

 The apex forms a well-marked " pseudo-temporal lobe," extending 

 downwards and forwards over the crus cerebri and optic tract to 

 the anterior perforated spot. 



The sujjra-callosal gyrus is 8 mm. in breadth and subdivided 

 by a well-marked small vertical sulcus into a larger outer mass, 

 or gyrus of Andreas Retzius (hippocampus nudus), 5 mm. in 

 breadth, and a smaller pyriform dentate fascia, the narrow end 

 of which lying behind the splenium is 2 mm. wide, the broader 

 end 5 mm. The sulcus limitans is also well marked. 



The anterior corpus quadrigeminvim measures 15 mm. in length 

 by 12 mm. in breadth, while the posterior is 7 mm. in antero- 

 posterior diameter and 9 mm. transversely. 



So far as I am aware the brains of the Musk-ox and Gnu have 

 not been described. For comparison, therefore, two brains from 

 the Society's collection have been vised, those of a Barbary sheep 

 and an Anoa. The latter is characterised by Elliot Smith as the 

 simplest and most generalised Ox-brain, The three brains are 

 very nearly the same size and have been preserved in formalin 

 for about the same time. 



The brain of Budorcas appears much simpler than that of Ovis, 

 x)wing chiefly to the absence of the numerous small isolated sulci 

 or secondary branches of the main sulci which are found in the 

 sheep. The cruciate upturning of the intercalary sulcus is rather 

 less marked in Ovis and the transverse sulcus does not meet the 

 suprasylvian. The arrangement of the orbital is rather difi'erent ; 

 this sulcus does not join the anterior terminal but the rhinal in 

 Ovis. The Sylvian appears to rise from the rhinal and the 

 diagonal is distinctly U-shaped, embracing the anterior vertical 



