174 General Notes. [February, 
nected with the tibia; if there is only one, this must be the 
tibiale. Two elements are attached to the fibula—the intermedium 
and the fibulare. Four metatarsals are preserved, but it is pos- 
sible that there were five. Each of the four metatarsals is sup- 
ported by one tarsal bone. Between the four bones of the distal 
series and those of the proximal one there are to be seen four 
additional bones, The inner one I consider the tarsale,, belong- 
ing to the first digit not preserved. The remaining three bones 
must be considered as three central bones. 
If two bones are connected with the tibia, the outer one repre- 
sents the tibiale, the other one a centrale, reaching the tibia in the 
same way as in Salamandrella (Wiedersheim). In this case, we 
have four central bones. Between the fibulare and tarsale, there 
is a large space without any bones. There is little doubt, I think, 
that there existed a sixth tarsal bone in the distal series, as in 
Cryptobranchus, remaining cartilaginous, and therefore not pre- 
served, 
Wiedersheim’ described three central bones in the tarsus of the 
Axolotl; fig. 8, pl. xxx, comes nearest to the condition in Arche- 
gosaurus, 
There are two explanations of the morphology of the tarsus in 
Archegosaurus, if there are five digits : 
1. Tibiale, intermedium, fibulare; centrale,, centrale,, centrale; 
tars.,, tars.o, tars.;, tars.,, tars.s, tars... 
2. Tibiale, intermedium, fibulare ; centrale,, centrale,, centrales, 
centrale, ; tars.,, tars.,, tars.s, tars.,, tars.s, tars.g. 
Archegosaurus belongs to the Rhachitomi, the oldest batra- 
chians known. The presence of certainly three, perhaps four central 
bones, is a new proof for the correctness of the position given to this 
group by Frofessor Cope-—Dr. G. Baur, Vale College Mus., New 
Haven, Conn., Dec. 17, 1885. 
THE INTERCENTRUM OF Livinc RerTILIA.—The Pelycosauria of 
the Permian formations possess intercentra in the dorsal, lumbar 
and sacral regions. In no living reptile have intercentra been 
described, so far as I know, in that part of the column, excepting 
in Sphenodon (Hatteria)? I find them also in Gecko verticillatus 
Laur. (G. verus Gray). In these forms intercentra are developed 
between a// vertebre. 
It is probable that the same elements will be found in the 
other Geckonidze and in the amphiccelian Uroplates, the only 
genus of the family Uroplati 
Lumbar intercentra in the Mammalia are first mentioned by 
Owen’ in the mole. Meyer* finds these elements also in the pos- 
1 Wiedersheim R. Ueber die Vermehrung des Os centrale im Carpus und Tarsus 
des Axolotis. Morph. Jahrb., Bd. v1, 1880, pp. 581-583, pl. xxx. 
3 brecht, Bull. Mus. Roy. Hist. Nat. Belgium, 1883, p. 
