1893] NOTES AND COMMENTS 157 



inception by De la Beche in 1835 to its organisation at the present 

 day. Some technical details as to the staff and field-work during 

 1897 next follow; and then the new results are summarised in 

 readable form under the respective geological formations, taking 

 them in order from the oldest to the newest, It is difficult to make 

 an adequate abstract of this summary, and it must thus suffice to 

 enumerate a few noteworthy points. Penologists will find much 

 important new matter in the description of the old rocks of the 

 Scottish Highlands, while stratigraphical geologists will probably 

 turn with greatest interest to the account of the Scottish Silurian 

 formations, in which an entirely new fossil fish-fauna has been dis- 

 covered. The recognition of Upper Carboniferous strata in the Isle 

 of Arran is also important, although no workable coal-seams have 

 yet been found. In Mesozoic geology there is little to record, but 

 the memoir on the Upper Cretaceous formations is evidently making 

 good progress. In Pleistocene geology there is a wealth of new 

 observations, which students of the glacial period will truly welcome. 



New Silurian Fishes 



The discovery of Scottish Upper Silurian Fishes mentioned above is 

 briefly reported upon by Dr Traqtiair, and when fully investigated is 

 likely to prove one of the most important contributions to Biology 

 of recent years. Among these fossils there seems to be clear evi- 

 dence of a new group of the fish-like organisms now commonly 

 known as Ostracodermi. The new forms are indeed likely to afford 

 important additional information as to the affinities of this problema- 

 tical group, which has hitherto been best known to us by Pteraspis, 

 Cephalaspis, and Pterichthys. Still more important, however, are 

 nearly complete skeletons of the primitive fore-runners of the sharks. 

 It has long been suspected, on theoretical grounds, that the paired 

 fins of fishes were originally continuous lateral folds of skin sup- 

 ported by parallel bars of cartilage. A few years ago some approach 

 to this condition was observed in the American Lower Carboniferous 

 shark, Cladoselachc. It now appears, from Dr Traquair's brief notes, 

 that still more important examples of the same arrangement are to 

 be observed in the Upper Silurian genera, exactly where the primi- 

 tive disposition of parts ought to be found according to theory. 

 Biologists, will anxiously await the completed memoir on these 

 remarkable new organisms. 



Extinct Phinocekoses 



The rhinoceroses are typically Old World animals at the present 

 day, and for many years the discoveries of fossil forms seemed to 

 show that they had always been so. It soon became evident from 

 fossils that the rhinoceroses could be gradually traced back both in 



