20 BAUR. [Vol. VII. 



centen Formen kurz, an seinem proximalen Ende verbreitert 

 und mit der Gelenhflache allda gegen den grosseren Knochen 

 der zweiten Tarsalreihe, das Cuboid, gerichtet, mit welchem er 

 articulirt. 



"Die Phalangenknochen (ph) zeigen die den heutigen Echsen 

 zukommende Zahl, namlich 2 fiir die grosse Zehe, drei fur die 

 zweite, vier fiir die dritte, fiinf fiir die vierte und vier fiir die 

 fiinfte Zehe. Auch in ihrer Form entsprechen sie jenen der 

 recenten Verwandten. Die Krallenglieder, nur an der grossen 

 und an der zweiten Zehe noch deutlich, an den iibrigen meist 

 nur als Abdruck sichtbar, sind ziemlich gross, unten concav (was 

 am zweiten seitlich liegenden erkennbar ist) und nach vorne 

 etwas zugesptzt." 



There cajmot be any doubt whatever that the hind foot of 

 " Hydrosanrus lesinensis'' is typically Lacertilian, has no trace 

 of any archaic stnictiire, not approacJiing in any way whatsoever 

 the Batrachian type. 



There is no evidence to consider the Dolichosaurs as a more 

 generalized group of the Squamata. The supposition that the 

 ancestral groups of the Squamata had a larger number of cer- 

 vicals than the more recent ones is not supported by any facts. 

 On the contrary, there is much evidence that all the forms with 

 longer necks have developed from forms with shorter necks, in 

 which the "original " number has been not more than eight. It 

 is only surpassed among living forms by the Varanidae, in which 

 we have nine cervicals. All forms which show a greater or 

 smaller number of cervicals have with very little doubt devel- 

 oped from forms with eight cervicals. 



According to Boulenger the ancestors of the Lacertilia had 

 many cervicals. This number became gradually reduced, until 

 the Rhiptoglossan number five was reached. This is at least an 

 improbability ; for we would have to imagine that the Rhyn- 

 chocephalian ancestors of the Squamata had a great number of 

 cervicals, which doubtless was derived from a smaller number. 

 In other words, we would have at first increase in number, then 

 gradual decrease again ; but there is no evidence for such a 

 supposition. 



It seems to me very much more probable and more natural 

 to assume the following course of development : — 



The Rhyncocephalian ancestors of the Squamata possessed 

 eight cervicals. All the generalized Squamata originally showed 



