350 LIEUT. R. BROOM ON THE 



developed and of about uniform width. On passing back, the 

 upper and middle part becomes thickened ; then a little further 

 back the lower half widens out and becomes divided by a median 

 cleft into the two I'ecurrent cartilages, as seen in fig. 8. Though 

 in this section the alinasal is seen detached from the re- 

 current cartilage, they are seen united a few sections further 

 forward. If this section be compared with a corresponding 

 section in I'alpa, such as shown in fig. 2, it will be observed that 

 though there are many minor differences there is considerable 

 agreement. Even the somewhat corresponding section which 

 I have figured in Oymmira will be seen to agree fairly well, 

 while the corresponding section in Tupaia will be seen to differ 

 very greatly. 



On passing a little further back, the septal cartilage becomes 

 divided into an upper and a lower part. The upper part soon 

 becomes greatly reduced, and then completely lost, while the 

 lower part is continued backwards as a rounded cartilaginous rod. 

 In fig. 9 the section passes through the anterior part of the 

 papilla. The recurrent cartilages lie by the base of the septum. 

 The upper nasal cartilages are considerably reduced. 



Fig. 10 represents a section further back. It shows the 

 anterior part of the naso-palatine canal. On the one side, 

 Jacobson's duct is seen opening into it. At this plane the oidy 

 cartilaginous support of the ducts is the anterior extension of 

 the posterior nasal-floor cartilage. The recurrent cartilage is still 

 of large size. 



Fig. 11 repi'esents a section near the plane where the naso- 

 palatine canal opens into the nasal cavity. The recurrent 

 cartilage is greatly reduced. Jacobson's duct is seen supported 

 by anterior processes of Jacobson's cartilage. 



Fig. 12 represents a section a short distance behind that shown 

 in fig. 11. A small process of the recurrent cartilage is still seen, 

 and quite free from Jacobson's cartilage. Jacobson's cartilage is 

 united at its outer lower side to the posterior nasal-floor cartilage. 

 This is a most unusual condition, and, so far as I am aware, is 

 only known elsewhere in Frocavia. 



In fig. 13 Jacobson's organ and the cartilage are well developed. 

 There is a small nasal-floor cartilage still seen. The palatine 

 processes are large and pai-tly roof over the organ. Above the 

 palatine process is seen the anterior end of the vomer. 



Fig. 14 is considerably further back. The vomer nearly clasps 

 the nasal septum. Jacobson's cartilage rests on the palatal plate 

 of the maxilla. The palatal processes, though thin, are still of 

 large size. In this same section, though not shown in the figure, 

 is seen a large inferior turbinal supported b}' a slender tui-binal 

 bone, and further up on the outer nasal wall a verj' well developed 

 glandular ridge. 



Centetes presents a number of unusual characters. It agrees 

 with Gymnura and Talpa in that Jacobson's organ has a long 

 narrow dvict which opens into the anterior end of the naso- 



