Field Notes. 157 



utilised as the source of the required information ; not merely 

 because of this coincidence, but because, for very diverse 

 reasons, the movements of both groups depend on their definite 

 attachment to the same forest-clad regions, and are thus put 

 in motion by the same impulses. 



A very slight consideration of the fossil Felid(B of America 

 reveals the significant truth that, whilst in North America, 

 deposits of lower Miocene age produce very freely the fossil 

 remains of the primitive Felid genera Dinictis and Pogonodon, 

 and such genera or their known descendants continue to the 

 strata of Pleistocene times, on the contrary, in South America, 

 the earliest Felidce appear in late Pliocene or Pleistocene beds 

 of South Brazil and the Argentine Republic in the form of the 

 genus Smilodon which occurs in older Texan deposits. Here 

 we see no uncertain indication that for countless ages access 

 to South America from the North was harried, only to become 

 feasible in late Pliocene times ; from this it is evident that the 

 seismic disturbances ending in the appearance of the Isthmus 

 of Panama were events of the Pliocene Epoch. 



Organisms of widely separated affinities from the Felidce, 

 availing themselves also of the newly erected land-bridge, 

 passed down ; amongst them was the most specialised of the 

 Nacophora allies, the species Thyrinteina arnobia, which, like 

 the Jaguar; has colonised and holds the whole of the Inter- 

 tropical territories of North, Central, and South America. 

 [To he continued). 



Scarcity of Fieldfares.— Is the scarcity of these birds 

 this winter general or local only ? Can any explanation of 

 their diminution be given ? In the Colne Valley, bird ob- 

 servers — one at least with forty years' records, — have never 

 before noticed such a dearth of blue-tails, as they are locally 

 known. Only once has a meagre flight of six birds been seen 

 wheie ordinarily hundreds and thousands may be met with. 

 In the Fenay Beck Valley, also near Huddersfield, not a single 

 example has been noted. — Wm. Falconer, Slaithwaite, March 

 2nd, 1918. 



There is an almost complete absence of Fieldfares and 

 Redwngs in the British Isles this winter. Observers from all 

 parts are recording this unaccountable dearth, for which it 

 seems impossible to find an explanation. The severe weather 

 experienced during the winter of 1916-17 can hardly have 

 wiped them out altogether. Can it be that they have missed 

 these islands and passed down the coast of continent ? It would 

 be interesting to learn if many have been seen in the fighting 

 area. A small party of about fifteen fieldfares frequented the 

 fields behind my house for a few days in November but I 

 have neither seen nor heard of any since that month. — R.F. 



1918 May 1. 



