THE REDBBEAST. 183 



in catching him, and consigning him to his wicker prison. He was placed 

 in the carriage Avith the chikiren, who departed well pleased that they had 

 charge of their little favourite. Arrived at the vicinity of the town, they 

 opened the basket, and hade adieu to the robin, half hoping, however, that 

 they should find him at home when they returned. In this they were de- 

 ceived, for we never saw our pretty intruder again. Other birds of his kind 

 occasionally sought, and obtained our hospitality, but none were found so 

 fearless and so troublesome as he ; and none, as he did, ventured to follow 

 the members of the family into every part of the house, and to make them- 

 selves quite ' at home.' " 

 January 2bt7i, 1865. 



A LIST OF LAND AND FRESH-WATER MOLLUSCA, FOUND IN 

 THE VICINITY OF THIRSK. 



BY MR. JOHN H. DAVIES. 



I HAVE been much gratified at perceiving the increased degree of attention 

 which the geogi-aphical distribution of our native mollusca has lately re- 

 ceived, and have been greatly interested in perusing the valuable papers 

 upon the subject, which have, from time to time, been contributed to the 

 pages of The Naturalist. 



I am sending, herewith, a list of the species which have been ascertained 

 to occur in this neighbourhood, and will preface it by endeavouring to 

 furnish, in as few words as possible, a summary of the leading physical 

 characters of the district 



The north riding of Yorkshire is composed of two groups of moorlands ; 

 one in the west, the other in the east of the northern portion of the broad 

 valley, which, running north and south between them, fills up the whole of 

 the central surface of the county. Thirsk is situated about midway between 

 York and Darlington, five miles from the eastern edge of the valley. Conse- 

 quently, a ten mile circuit includes in the first place ; — in the west, a flat 

 low, level, and richly cultivated district, composed of red sandstone deposits, 

 overlaid with tertiary diluvium, which, in a natural state, has been closely 

 interspersed with bogs and pools of standing water. Secondly ; — in the 

 centre, a liassic band, about five miles in breadth, considerably undulated, 

 and thickly covered with wood ; and thirdly, in the east, a tract of elevated 

 country, belonging to the oolitic moorlands, rising abruptly out of the valley, 

 the margin of which is diversified in several places by precipitous cliffs and 

 scattered debris. But of the district indicated, only comparatively a small 

 portion has been explored conchologically, in a complete and efficient 

 manner. 



