]\I01?PH0L0GT OF THE BRAIX IX TITE .MAMMALIA. 343 



shown. This lie hihels " Schoitelstiick zii [postsylvian]." On the mesial surface 

 ho represents, in addition to the calcarine group and the intercalary, a small rosti-al and 

 two sulci labelled /3' and 7. Of these, j3' obviously represents the sh'ght depression 

 produced by the capsule of the floccular lobes, wliereas y represents tlie sulcus 1 liave 

 called " collateral " in Lemur. 



Like Flower, lie denies the presence of an iiisuhi (p. DOG) ; l)ut this arises from a 

 misconception as to the nature of tlie region so-called. Both writers mean that 

 a definite subm(>rged area is not found in this genus. 



Platau and Jaeobsohn repeat the curious error of Chudzinski and descril)e a brain, 

 which CAW be none other than that of Nycticebus tardigrddus, as being that of " Stenops 

 gracilis." For not only does it exhibit the plan of sulci distinctive of Ni/cticebus, but 

 its dimensions also are those of this genus and not those of Loris \_Stenoj)s]. If the 

 brain which they describe really belongs to the genus Loris, we should have expected 

 some comment from the authors as to its aberrant characters, w'hich a comparison of the 

 memoirs of Beddard and Ziehen ought to have demonstrated. [Moreover, a study of 

 their account (' Ilandbuch,' last few lines on p. 191- and p. 195) might lead one to suppose 

 that the authors do not clearly distinguish between the terms Loris gracilis, Stenops 

 gracilis, Stevops lardigradus, Stenops javanicus, and Nycticebus tardigradus.^] 



The condition of their specimen differed from that of mine in possessing a separate 

 postlateral sulcus and an inferior temporal. In these respects, as w^ell as in the features 

 of the mesial surface, it resembles the specimen in the College of Surgeons. 



The sulci which Ziehen called " central " the above authors regard as " precentral." 

 Otherwise they closely follow the teaching of the Utrecht psychologist. 



They represent certain small furrows, which have not been mentioned above, such as 

 those labelled " Spur eines Sulcus fronto-orbital " and " Fissura sublimbica posterior." 



In addition to these records, I have examined two crania of this genus, and from one 

 a plaster mould of the brain-cavity was made. 



In one specimen (College of Surgeons, specimen 293, labelled "ior^ y«y««eCT<s") 

 I found characteristic snprasylvio-lateral, postsylvian, and orbital sulci, the triradiate 

 coronal -\-x-^y complex, and the sulcus/. In addition there was a separate postlateral. 



There seemed to be a dingonal sulcus between the sulcus x and the Sylvian complex, 

 but of this I cannot be certain. 



The other specimen, ^^ hieb was given me by Captain Stanley Flower, presented a pattern 

 which differed from the last in the absence of any trace of a diagonal sulcus ; it also 

 possessed modifications of the upper ends of the postsylvian sulci in the two hemispheres 

 exactly analogous to those found in the respective hemif^pheres of the brain in the 

 College of Surgeons. Thus the upper end of the sulcus was bent forward on the lel't 

 liemisphere ; but bifurcated, and its chief branch bent back on the right side. There is 

 also an inferior temporal sulcus. 



It is interesting to note in these two casts that there is a definite postlateral sulcus in 

 all four hemispheres, and in none of them is the caudal extremity of the lateral sulcus 

 bent inward, as is invariably the case w^hen the separate postlateral sidcus is absent. A 

 comparison of the brain-case of my type specimen with the other cranium from Ghizeh 



SECOND SERIES. — ZOOLOGY, VOL. VIII. 51 



