248 ADAMS: DERBYSHIRE FROM A CONCHOLOGIST's POINT OF VIEW. 



(2) The Limestone District, of oblong form with Hather- 

 sage, Chapel-en-le-Frith, Ashbourne, and Derby at the corners. 

 Here I expected to reap, and have reaped, an abundant harvest. 

 Helix rupestris, which I have never taken anywhere but on the 

 limestone, is found along the stone walls from Chapel half way 

 to Castleton, and from here it spreads southwards over all the 

 district. This road forms a sharp line of demarcation between 

 the grit and the limestone, and the complete manner in which 

 molluscan life is bounded by the former is very marked. At 

 Castleton there is a patch of limestone — the ^Vinnats — where, 

 in one small spot, several forms of Zonites are to be found, and 

 II. arbustoriim with many varieties flourishes, also here and 

 there H. lapicida. The region of Peak Forest (which I hardly 

 need mention is not a tract all covered with trees — the word 

 retaining its original meaning) should be worked for Zonites. 

 The neighbourhood round Buxton is noteworthy for the abund- 

 ance of Z. alliarius var. viridula which is more common than 

 the type in the proportion of three to one. I made an interest- 

 ing" capture here of a specimen of the type in cop. with the 

 variety. By the way, I have noticed that this variety nearly 

 always differs from the type in its coarser sculpture and more 

 elevated spire. Ashwood Dale and Miller's Dale were dis- 

 appointing, the former locality only producing H. pygnicea as 

 worthy of mention, though here, too, I have only collected in 

 winter. The line of the High Peak Railway should be searched 

 for Bulimus obsciirus., Pupa mnbiUcata, &c. Deepdale abounds 

 in Zonites punts, fine Helix nemoralis var. libellula 00000, &c., 

 and in the stream at the bottom of the gorge is L. truncatiila. 

 The valley of the Derwent is a good field, especially from Bake- 

 well to Matlock. In the neighbourhood of the latter Clausilia 

 laniinata and Helix lapicida swarm over the tors after a shower 

 of summer rain, and Bulimus obscurus and Cochlicopa tridens 

 may be scraped out of the mossy niches. Around Bakewell 

 the hedges arc studded with Helix arbustorum and its pale 

 varieties. The valley of the Dove, in spite of its limestone 



J.C., vi., July, 18.90. 



