240 Bulletin American Museum of Natural History. [Vol. XX^'II, 



upon the proof that this West x\frican genus is truly an aquatic offshoot of a 

 Microgale-\ike form and thus not the type of a very distinct family l)ut merely 

 an outlying member of the Madagascan Centetidse. 



In support of this view Leche (1907, pp. 127-129) has adduced consider- 

 able evidence. In the first place the diet of Potamogale is, for an Insectivore, 

 aberrant and peculiar, since it subsists upon fish, for the capture of which 

 its whole organization is aberrantly modified. In its antemolar dentition 

 Potamogale parallel Cijnogale benneti, a Viverrid of similar aquatic piscivo- 

 rous habits (Leche). But this peculiar antemolar dentition of Potamogale 

 is linked morphologically to that of the very primitive Microgale by way of the 

 intermediate conditions in Limnogale. Secondly, Potamogale is connected 

 with Microgale by the profile and ventral contour of the skull, by the arrange- 

 ment of the pterygoids, by the form of the glenoid fossa, by the fused nasals, 

 etc. (Leche, 1907, p. 128), and to this list may be added the resemblances in 

 the auditory region and the close agreement in the position of the principal 

 foramina. 



The peculiar syndactyly of the second and third digits in the pes of 

 Potamogale (suggestive of the Marsupial syndactyly) is shown by its late 

 appearance in the embryo to be a relatively recent acquirement (Leche). 

 Potamogale is likewise more highly specialized than the remaining Centetidse 

 in the following characters: (1) large size, as compared with Microgale; 

 (2) peculiar newt-like swimming habits; (3) total loss of clavicles and highly 

 modified manubrium sterni: (4) loss of entepicondylar foramen (very un- 

 usual in lipotyphlous Insectivora) ; (5) loss of gall bladder; (6) descent of 

 the testes into a true "cremaster sack"; (6) change from insectivorous to 

 piscivorous habits. In view of these marks of high specialization and at 

 the same time of derivation from a Microgale-\ike form it now seems con- 

 trary to the balance of evidence to accept the view, as the writer formerly 

 did (in Osborn, 1907, p. 225) that the tritubercular molar type of Potamogale 

 was prototypal to the molar types of the remaining Zalambdodonts. 



THE SOLENODONTID/E. 



Solcnodon was considered by Dobson (1882, p. 87) to be the type of a 

 family "distinct from Centetidae but, nevertheless, associated with it and 

 Potamogalidfe in the same group or superfamily Centetoidea" (see also 

 /. c, p. 96). Dobson laid stress (p. 87) on the analogies in the skull between 

 Solenodon and the Talpoid genus Myogale, but Leche (1907, p. 145) thinks 

 that "Dobson hat den Unterschied zwischen Solenodon und Centetidse 



