ON THE MILK-DENTITION OF THE RATEL. 221 



in strohila. l^esies niomerous, at least 200 lying fosteriorly in a 

 thin iiertical plate extending between ivater vascular vessels and 

 even beyond them laterally^ imbedded in interstitial tissue different 

 from medullary jmrenchyma. No vesicida seminalls, sperm-duct 

 with large coil ; cirrus sac large, containing a looped part of sperm- 

 duct, short cirrus, and an evaginable sac derived from cloaca geni- 

 talis. Ovaries and vitelline gland in front of testes. Uterus in 

 front of ovaries, a narrow transverse sac with cavity partly divided 

 by ingroioing trabecula;. Later uterus converted into several spherical 

 sacs. Eggs thin-ivalled, surrounded by mitritive (?) cells. 



Hab. Ewpodotis kori. 



The most noteworthy characteis of the genus, so far as ttie 

 external cliaracters go, appear to be the rather wide and 

 rudimentary rostellum, which is, nevertheless, aimed with very 

 numerous though very minute hooks. The internal structure is 

 remarkable for the restriction of the gonads to the extreme 

 posterioi- part of each segment, and to the fact that the very 

 numerous testes airanged only one deep are imbedded in a very 

 different kind of medullary parenchyma, which is obvious to the 

 eye on account of its feeble staining : by the peculiar form of 

 the cirrus sac and the inclusion within it of an outgrowth of the 

 genital cloaca, which is probably protrusible like the somewhat 

 similar " penis " of Anojjlotcenia : and by the fate of the uterus and 

 the presence of inteistitial cells lying among the eggs. 



14. On the Milk-Dentition ol:' the Ratel. 

 By R. Lydekker. 



[Received September 30, 1911 : Read November 21, 1911.] 



(Text-figures 31 & 32.) 



Many instances are known among extinct mammals in which 

 the milk-dentition presents primitive features entirely lost in the 

 teeth of the permanent series. In the equine Merychipjyus, for 

 example, the cheek-teeth of the milk-series are of the short- 

 crowned cementless type of Anchitherium, whereas those of the 

 permanent set show the high ci'owned and cemented type cha- 

 racteristic of the more specialised repi'esentatives of the family 

 Equidffi *. So far, however, as I am aware, no such atavistic 

 features have been recorded in the case of any existing mammals ; 

 and it is therefore of interest to bring to notice what appears to 

 be a case of this nature. 



In the ninth edition of the ' Encyclopjedia Britannica,' Sir 

 William Flower classed the Ratels (Mellivora) with the Badgers 

 in the subfamily Melinag ; this classification was followed in 

 Blanford's volume on Mammalia in the ' Fauna of British 

 India ' t and in Flower and Lydekker's ' Study of Mammals ' J. 



* See Lull, Amer. .J. Science, vol. xxiii. p. 177, 1907. 

 t Page 175, 1888. % Page 576, 1891. 



