164 SECTION B. VERTEBRATA. 



I hope soon to be able to make a clear and satisfactory state- 

 ment about these questions ; for the present I would confine myself 

 to pointing out the considerable difference of opinion as to the 

 real names that must be applied to these bones, and especially 

 about the true nature of the bone that forms the outer boundary of 

 the temporal perforation. This bone is now generally taken to be 

 the squamosum, a view which was already held by Owen and 

 Kostlin, but which forcibly leads to the conclusion that a jugal 

 (malar) bone is wholly absent, and furthermore involves the diffi- 

 culty to find an explanation for the large squamous upward exten- 

 sion of the petrous bone, which occurs on the inner side of this 

 so-called squamosum and excludes it from the walls of the brain- 

 cavity. By Owen this upper prolongation of the petrous bone 

 is called the mastoid ; Kostlin takes it to be a posterior temporal 

 ala of the sphenoid. Assuredly its position shows much resem- 

 blance to the mastoid of other Mammals, but also to the opisthoti- 

 cum of Testudinata. This and other questions can only be 

 satisfactorily settled by the investigation of young stages, showing 

 all the sutures, and by careful comparison to other Mammals and 

 to Reptiles. 



Prof Seeley concurred with Dr van Bemmelen's views, and 

 referred to his forthcoming paper in the Phil. Trans. 



5. Mr Graham Kerr made some remarks on 



An Exhibition illustrating the Life-history of 

 Lepidosiren (with lantern slides). 



The Secretary remarked that these numerous and important 

 results have been laid before the Congress within ten months of 

 Mr Kerr's return from his expedition. 



