340 D. M. S. Watson — On MicropJwlis Stowi, Huxley, 



tree-trunks are now being prepared for fossilization in Canadian lakes 

 and rivers.^ 



[_I^ote. — Excellent sound timber for gate-posts and otlier agricultural 

 purposes is obtained both in Scotland and Ii'eland from the perfectly 

 preserved bog-oak and other trees found in the peat. The piles of 

 the Swiss lake-dwellings (of Stone and Bronze age) testify by their 

 soundness the durability of wood under water, the only important 

 change being their hlacke^ied condition. — Ed.] 



EXPLANATION OF PLATE XI. 



Portion of a trunk of Lepidodcndron veltheimianum, Sternb., from French, 

 Lick, Ind. J nat. size. 



The specimen represents a mould composed of fine sihceous sediments which 

 have been deposited inside a section of empty bark trunk. A portion of the 

 original carbonized bark which still adheres to the mould is seen in the dark 

 irregular patches. 



II. — MiCROPHOLis Stowi, Huxley, a Temnospondtlous AMPHiBrAjr 

 FROM South Africa. 



By D. M. S. Watson, M.Sc, Lecturer in Vertebrate Palaeontology in University 

 College, London. 



Ji/TICROPHOLIS Stowi was described by Huxley in 1859 from 

 a small and very incompletely preserved skull found by 

 G. W. Stow at Rhenosterberg (north-west of New Bethesda), District 

 Graaf Reinet, Cape Colony. Subsequently R. Owen described another 

 specimen as Petrophryne granulata. In his description he suggested 

 that it might prove to be identical with Huxley's type. The British 

 Museum now contains these two type-specimens and three other 

 examples of the form, all except Huxley's type being from the 

 Proeolophon zone of Donnybrook, Upper Zwartkei, District 

 Queenstown. 



Owen's excellent description and beautiful figures have already 

 made clear the general structure of the roof of the skull, but it is 

 now possible to make out some more sutures, all of which are 

 represented in Fig. 1. The most remarkable features are — 



1. The small bone between tlie premaxillse. This is a small bone 

 with the same ornament of tubercles as the other skull bones, lying 

 rather loosely in a small fenestra left between the internasal processes 

 of the premaxillse. The fenestra is present in the three specimens 

 which show this region, and in one small skull it is not filled with 

 a bone. I can find no exact parallel for this bone, but in two types, 

 Sclerocephalus Roemeri (H. v. Meyer) and a small Stegocephalian, 



^ Dr. G. E. Wieland, who kindly read the MS. of this paper, has furnished 

 the following interesting memorandum : Indeed, it is curiously in accord with 

 the foregoing facts that in the Palasozoic the thin rind of bark not only tended 

 to outlast the wood in various types, but in turn sometimes aided in the 

 conservation of lesser stems subsequently floated into the bark cavity. In the 

 Laggan Bay bark cylinder figured by Seward no less than five of these floated-in 

 Lepidodendron stems appear in fair conservation, while the fact that the 

 cuticular layer must have been remarkably resistant is fully attested by the 

 well-known occurrence in the Permian of Tonea of the thin bands of "paper 

 coal ", made up as shown by Weiller of the little-changed and I'eadily stained 

 cuticles of Bothrodendron. 



