I 



NEW SPECIES OF LABYRINTHODONTS. 291 



resemblance in dental characters to the specimen under consideration 

 as to lead to the conclusion that the latter cannot be generically 

 separated. The teeth of the several Permian species of Macromeriam 

 are described as conical, with the crowns smooth near the summit but 

 deeply grooved interiorly, and bearing distinct fore-and-aft carinae ; 

 while they have a well-marked pulp-cavity, and complex labyrinthic 

 foldings at the base. The figures given by Pritsch, together with a 

 cast of part of the jaw of the typical M. Schwarzenbergi, now in the 

 British Museum, show that the outer surface of the teeth was 

 markedly convex ; while the summits of the crowns were more or 

 less bent backwards. M. Schiuarzenhergi was a much larger form 

 than the one under consideration ; but the fragmentary upper jaw 

 represented in pi. Ixvii. fig. 15 of the work cited, under the name of 

 M. hicolor, has teeth agreeing in size with those of the Gilmerton 

 jaw. The magnified views of these teeth, given in plate Ixx. of the 

 same volume, show an internal structure which, so far as I can 

 determine, is very similar to that of the Gilmerton specimen. The 

 crowns of the upper teeth are, however, more curved backwards in 

 M. hicolor ; and if the same condition holds good in the lower jaw, 

 we shall have a character by which the Carboniferous species can be 

 readily distinguished from the Permian one. The lower geological 

 horizon of the Gilmerton jaw is, however, of itself sufficient to 

 indicate its specific distinctness from M. hicolor, and I therefore 

 propose to make that specimen the type of a new species, which 1 

 refer (at least provisionally) to the genus Macromerium, with the 

 n?iViiQ oi M. scoticum. This species may be defined as agreeing in 

 size with M. hicolor, but with the crowns of the lower teeth less 

 recurved than the upper ones of the latter. 



Tf I am right in the generic reference (and, in any case, the Car- 

 boniferous form must be closely allied to Macromerium)^ we shall 

 have the same vertical range in the case of Macromerium as is 

 given by Dr. Fritsch in that of Loxomma. 



B. Mandible and Inter cent rum from South Africa. 



Among a series of specimens from the Karoo system of Squth 

 Africa, presented to the British Museum by Sir B. Owen, is the 

 greater portion of the right ramus of the mandible of a com- 

 parativel}^ large Labyrinthodont, together with an intercentrum 

 which, from its size and mineral condition, appears to have belonged 

 to the same individual. The precise locality where these specimens 

 were obtained is unknown : and there is likewise no evidence 

 to show whether they were derived from the Beaufort or Stormberg 

 beds of the Karoo system. 



The mandibular ramus is in three fragments, which, when put 

 together, indicate that its entire length was somewhere about 

 40 centimetres. The portions remaining comprise the entire arti- 

 cular region and the greater portion of the dentary and associated 

 elements, together with a fragment of the missing intermediate 

 portion. The anterior portion of this mandible is represented, from 



