2p4 Report S.A.A. Advancement of Science. 



ANOMOnOXTIA. 



Medium sized reptiles, with the teniiioial region supported !)> a 

 single lateral arch, rostfrontals usually absent (pre.sent in Lystro- 

 saurus). No supra-temporals or quadi-ato-jugals. Squamosals and 

 quadrates large. Pramaxillaries united, toothless, and very large. 

 An imperfect .secondary palate formed l)y the maxillaries ami 

 palatines. True median vomer well developed. Prexomers absent. 

 Occipital condyle, single tripartite. Scapula with a well-developed 

 acromion, ('leithrum ])resent in Dicynodon. al)sent in J,ystrosatirus. 

 Phalangeal formula :;. 3. 3. 3. 3. 



FamiK : Kndothiodontida.^ 

 One or more series of molar teeth present on maxillaries 

 dentaries. Interclavicle a rounded plate. 



(lenera : Endothiodon. 

 Esoterodoii. 

 Cr\ |)toc\ nodon. 

 Pristerodon. 



Familv : Dicvnodontida?. 

 Maxillarv teeth absent, or i)resenl as a pair ot tusks. No 

 teeth on dentaries. Inlerclaxicle elongated, 

 (lenera: Dicvnodon. 

 ( )uden( xlon. 



Family : Lystrosauridas. 

 Dentition as in Dicvnodontida;. -A pair ol poslfrontals 

 present ; also a distinct prepaiietal i>one. huerclavicle 

 small. Xo cleithrum. 



Oenera : L\strosaurus. 

 ? Gordonia. 

 ? Geikia. 



Kamilv : Gistecephalidae. 

 [Oistecephalus. though imperfectb known, is probably 

 entitled to be regarded as the i\pe of a distinct familv. 

 It differs from Dicvnodon and Lxstrosaurus in th2 

 structure of the quadrate and occipital regions.] 

 Genus: Cistecephalus. 



[Addendum, jylh Ocloiier. 1903. Since the abo\e pa])er was 

 read it has been discovered that a i)reparietal bone is not jieculiar tn 

 the Lystrosauridae. being present also in the other families of the 

 .^nomodontia. — R.H.] 



