ON THE SKULLS OF CYNODOXT REPTILES. 893 



Plate XLIV. 



Fig. 1. Stacln/ndex f/ilchrisfi, sp. ii., part of bvaiicli of. X 8. 



2a. EiipleA-aura media, sp. ii. Spicules of central trunk. 

 2h. ,, „ ,, Spicules of external trunk. 



2 c. ,, ., „ Spicules of polyps. 



3 a. Tliouarella 7iicl.soiii, up. n., verruca oL X 45. 



Sh. „ „ ,, apex of verruca of. X 100. 



4fl. lluriceidesfitsca, sp. n. Spicules of upper part of polyp. 

 4b. „ „ „ Spicules of lower part of polyp. 



4 c. „ „ „ Sjiicules of ccBiienchyina. 



Plate XLV. 



Fig. ]. Thnuarella JiicJcsoni, sp. n. Spicules of verruca. 

 2a & b. Stachi/ndes gilchristi, sp. n., sclerites of. 

 3 17. Psammofforffia pulcJira, sp. n., red spicules of. 



3 h. „ „ „ yellow spicules of. 

 4a. Suberia capcnsis, sp. n. Spicules of central trunk. 



4 6. „ ,, „ S|)icnles of external trunk. 

 4 c. „ „ „ Spicules of polyp. 



38. On the Structure of the Skull in Cjnodont UeptiJes *. 

 By U. BuooM, M.D., D.Sc, C.M.Z.S. 



[Received April 10, 1911 : Read May 23, 1911.] 



(Plate XLVI.t and Text-figures 168-180.) 



Hlstoriccd and Introductory, 



In 1853 tlie British Museum received from AndreAV Bain the 

 first known skulls of fossil reptiles with a mommal-like arrange- 

 ment of the teeth. These ultimately hecame the types of 

 Lycosaurus tigrinus and C'ynodraco serrideiis. In 1858 Sir 

 George Grey presented the skulls which were shortly afterwards 

 described by Owen as Qalesaurus planiceps and Cynocham/psa 

 laniaria. The Galesaurus skull though crushed was nearly 

 complete, and being so very remarkably mammal-like Owen 

 almost immediately described it in a paper read before the 

 Geological Society on 20th April, 1859. 



Although for seventeen years nothing further descriptive of 

 any of the reptiles with a mammal-like dentition was published, 

 it is necessary to briefly consider some of Owen's other woi'k in 

 the interval to clear up a certain confusion of nomenclature. In 

 1859 Owen gave to the Avorld his famous classification of the 

 fossil reptiles, and though he formed the Order Anomodontia 

 for the South African reptiles of the Dicynodont type, he care- 

 fully omitted all reference to those reptiles, like G'cdesaurus and 

 Cynochampsa, with a mammal-like dentition. "When in 1861 he 

 published his ' Palaeontology,' feeling compelled to put the 

 remarkable Gcdescairus somewhere, he made it the type of a 

 " family " of the Anomodontia, calling it the Cynodontia, doubtless 



* On p. 902 Dr. Broom names a new species, viz. C^iioffnathus seelcyi. — Editoe. 

 t For explanation of the Plate see p. 925. 



