ORGAN OF JACOBSON IN THE INSECTIVORA. 353 



palatine canal near its anterior part. Jacobson's cartilage in 

 each passes forwards with the duct, and the naso-palatine canal 

 is supported by an anterior process of the posterior nasal-floor 

 cartilage. Whatever subdivision may on other grounds be made 

 of these Insectivores they all belong to the Coenorhinata, and 

 agree with most higher mammals, such as the Carnivores and 

 Ungulates. 



Ihtpaia and Macroscelides agree in having a Polyprotodont 

 marsupial type of structure, and cannot have any near affinity 

 with the typical Insectivores, and the order Menotyphla to which 

 they belong must be removed far from the Insectivora and 

 placed in quite a difi'erent phylum and not far from the early 

 Marsupials. 



Ghrysochloris, which has generally been regarded as allied to 

 Centetes, is seen to be in no way closely related to it. Like 

 Tivpaia, Chrysochloris belongs to the Archseorhinata, but it 

 cannot belong to the order Menotyphla. The resemblance of its 

 nasal structures to those of the Diprotodont marsupials is 

 puzzling, and until further work is done on the development 

 of Chrysochloris, one must hesitate in discussing its affinities 

 further. 



In 1883 Dobson *, in discussing the affinities of Chrysochloris, 

 wrote as follows : — " The natural j-elations of the species of the 

 family are with the Oentetidse, which they resemble in the form 

 of their molar teeth, in the absence of an interorbital constriction, 

 in the position of the testes, and in some important myological 

 characters ; but they also present many most important differ- 

 ences .... such as the presence and peculiar development of the 

 zygomatic arches, the presence of tympanic bullae, and the very 

 different form of the male generative organs, characters which, 

 while indicating separation at a very remote period from the 

 ancestral Centetidse, do not ally them with any other family of 

 recent Insectivora." 



The peculiar structure of the molars has been the main 

 character which has suggested an affinity with Centetes. But 

 we find a similar type of teeth in the marsupial Notoryctes, and 

 the similarity in the three genera is probably due to convergence, 

 and does not indicate any affinity. 



I hope shortly to undertake the study of the structure and 

 development of the skull, and may be able to throw some further 

 .light on the affinities of Chrysochloris. 



In the meantime I have no hesitation in removing it from the 

 Insectivora, and placing it in a distinct order, for which the 

 name Chrysochloridea, proposed by Dobson, may be retained. 



* A Monograph of the Insectivora, Systematic and Anatomical, Part II., 1883, 

 p. 108, 



