﻿406 Capt. MacdaMn — Northampton Ironstone Beds. 



Although many fish are common to the two sides of the Urals, 

 there is a greater difference between those on the east and those on 

 the west than that which appears to exist between the Mammalia. 

 Considering the difficulties that fish have in crossing a barrier of 

 land, this might naturally be expected. As examples we have 

 a species of Carp, Alburnus liicidus, only on the west side, and the 

 Guiniad, Coregonus leucichtys, one of the Salmonidce, only on the east. 



Upon the eastern side of the Urals we have a singular example of 

 the spread of a species in a district it was brought to colonize. This 

 is the Crawfish. Up to the year 1843 or 1844 it only lived on the 

 western side of the mountains, but about that time it was carried over, 

 and now the eastern rivers of the Middle Urals are alive with Crawfish. 



During the few weeks' ramble I had amongst the Urals, the season 

 was too far advanced for the collecting of many plants. However, 

 to the great surprise of a resident botanist, Mr. Onsieme CI ere, I 

 obtained a few, one or two of which proved to be of rare occurrence. 



Mr. Clerc's observations tend to show that the plants in their 

 geographical distribution about the Urals exhibit similar peculiarities 

 to those I have noticed as occurring amongst the animals. Thus we 

 have plants peculiar to the western side of these mountains, as 

 Asaruin europceum and Ajiiga reptans, and I may also add, I think, 

 Primula lorella and an Auricida. Then there are plants which are 

 seldom seen upon the western side, but are common in Russia, as 

 Veronica officinalis, Bunias orientalis, and Tragopogon orientalis. 

 Certain plants, as might naturally be expected, are only to be found 

 upon the high mountains of the North Urals; for example, Salix reti- 

 odata, S. herbacea, S.rotundi/olia, Dryas octapetala, Saxifraga punctata, 

 Pyrethrum hipinnatum, and Asplenium crenatum. Then, again, there 

 are plants which have only been found in the Alps and near St. 

 Petersburg, in addition to the Urals, as, for example, Hieracium 

 prenanthoides. Again, certain plants which are found in the Urals 

 stretch eastward into Siberia, such as Caltha natans, Actcea spictata, 

 A. oxycarpa, A. l-eucocarpa, and Aconitum volubile. Other plants have 

 an excessive range in this direction ; thus Bubiis Tiumilifoliws extends 

 to the Amoor, as also does Ranunculus PurscMi. 



Thus we see that the Urals, although not forming a formidable 

 barrier in the physical configuration of the globe, still play the part 

 of one in preventing an unlimited mixture of species, which is alike 

 evideiit both amongst the animals and vegetables, — a fact which, when 

 regarded geologically, is of considerable significance, more especially 

 v.dien we reflect upon their great antiquity. 



{To be continued in our next Number). 



III. — The Northampton Ironstone Beds in Lincolnshire. 

 By Captain Macdak.in. 



THE Ironstone Beds of Oolitic age in Lincolnshire have, during 

 the last four years, yielded not only large quantities of brown 

 hfematite iron-ore, but some very interesting sections and borings, 

 comprising thirty-one of the latter between four and seven miles 

 to the south of Lincoln, and several extensive openings showing 



