WINDSOR : SPECIES OB' THLASFI. 



61 



There is one otlier character of the plant which is I believe common 

 to all its localities, I mean the glaucous aspect of the foliage. This was 

 very decided in all the numerous specimens I saw a few days since growing 

 at Matlock, so that as applied to them, the name (were it derived from the 

 hue) of glaucum or glaucescens would be much more appropriate than that 

 of virens. , 



On the whole from a consideration of the subject and a fair comparison 

 of the plant from its different localities, I am of opinion that it may be 

 justly referred to one species — Tlilaspi alpestre. 



P.S. — Since writing the above, I have had an opportunity of comparing 

 recent specimens, collected three days previously near Malham four miles 

 from Settle, of TTdaspi alpestre which has been called occitanicum with the 

 Thlaspi alpestre of Matlock, which has been called virens, collected one day 

 earlier than the other. 



The Settle form agrees upon the whole pretty well with the description 

 of it in Bahington s Manual, the silicles being generally triangular- 

 obcordate — the notch from the diverging lobes very distinct, and the 

 style elongated. 



On the other hand the silicles in the Matlock plants (and I consider the 

 Teesdale one the same species) have a mixture of triangular-obcordate pouches 

 with some more, of an oblong form, so that there is little distinction in the 

 head, although the triangular-obcordate form perhaps slightly predominates 

 in the Settle form. The length of the projecting style is much the same in 

 all, and I believe I am correct in stating that the same remarks apply to the 

 Thlaspi alpestre from near l^amur. 



Manchester, June 1th, 1865. 



MY MARINE AQUAEIUM. 



Perhaps a few notes on the subject of marine aquaria may not be 

 uninteresting to some readers of the " Naturalist'", and may lead some of 

 them, during the coming summer to undertake the care of this interesting 

 ornament to a room. With this idea I beg to oifer them a few jottings from 

 my own experience, which however, I may say has not been of very long 

 duration. In fitting up mine I made use of a vase which had previously 

 been used for a fresh water aquarium, and in which the rock-work, made of 

 small stones cemented together with Roman cement, did not require any 

 previous preparation. Of course in building up rocks with this cement care 



