On the Origin of the Terraces, fyc. 



185 



Family Genus Species 



194 Larus minutus . 



195 Larus ridibundus 



196 Larus tridactylus 



197 Larus canus 



198 Larus fuscus 



199 Larus argentatus 

 190 Lestris cataractes 



201 Puffinus Anglorum 



202 Thalassidroma Wilsoni 



203 Thalassidroma Leachii 



204 Thalassidroma pelagica 



Yatesbury Rectory, Calne, 



VOL.PAGE 



Little Gull . . . xii. 173 

 Black-headed Gull . . „ 173 

 Kittiwake 

 Common Gull . 

 Lesser black-backed Gull 

 Herring Gull . 

 Common Skua 

 Manx Shearwater . 

 "Wilson's Petrel 

 Forked tailed Petrel' 

 Storm Petrel . 



Alfred Charles Smith. 



on THE 



pn%m of \\t %mum f JJalks, or Jpdjets 

 of % CJmlfe §oto- 



By G. Potjlett ScROPE, F.R.S., F.G.S., &c. 



F the natural features of the county of Wilts, none perhaps 

 are so prominent as its chalk downs. And they have con- 

 sequently attracted considerable notice from our local historians 

 and naturalists, from Aubrey down to the latest contributors to 

 this Magazine, in the last number of which alone two articles 

 describe their ancient earthworks and general character. But I 

 have vainly looked in any of these publications for a descriptive 

 account of what I consider to be some of the most remarkable 

 features of these chalk hills, viz. ; the numerous terraces, locally 

 called balks (banks?) or lynchets (ledges?), which frequently 

 score their slopes in more or less horizontal lines. These terraces 

 are perhaps most conspicuous between Mere and Hindon, and near 

 to Warminster and Market Lavington, but are indeed to be met 

 with almost wherever the chalk downs slope into the valleys or 

 low plains. No one travelling along the high roads which run at 



