July, 1889. 
REVIEWS. 
165 
Variety contortula .—Length, 24 mill. ; breadth of body- 
whorl, 9 mill. Shell small, narrow, thin, fragile, light horn- 
coloured ; aperture ( f total length of shell), same shape as in 
type ; bodv-whorl and the preceding whorl rounded and not 
babylonic ; the fourth and fifth whorls equal in size and 
markedly gibbous all round; suture of the spire markedly 
deep, but the suture between the body-whorl and the whorl 
immediately preceding it no deeper than in type ; spire 
subscalarid. Locality.—Pond in field at East Finchley, 
London. Collected by the describer. 
The pond in which I found what I have called var. 
contortula is thick with aquatic plants which probably may 
have had something to do with its scalariform nature ; the 
pond, however, in which Mr. Gude found what I have called 
var. elegans is personally known by me as containing but 
scant vegetation. As both these varieties are subscalarid and 
since one of them was found in a pond clear of vegetation, it 
seems to me that subscalarid specimens are not always 
explicable by the theory of Van den Broeck, who considers 
them as adaptive modifications. It seems but right, in 
conclusion, to say that Cockerell has described two varieties 
of Limnaa stagnalis as m. scalariform,e and v. elegantula (the 
types of which I have examined), but these are quite distinct 
in general form from the varieties here named and described. 
Cockerell’s two varieties will be found figured and described 
on pp. 78 and 79 of my “ Shell-collector’s Handbook for the 
Field.” The description of m. scalariforme is “whorls 
disunited ; ” that of v. elegantula is “ shell dark in colour, 
nearly scalariform ; suture deep.” The type of the former 
is in the National Collection in Cromwell Road, South 
Kensington ; the type of the latter is to be found in the 
Museum of the Middlesex Hospital Medical School, London. 
Hcfritfo s. 
A Flora of Herefordshire. Edited by William Henry Purchas, Vicar of 
Alstoufield, Staffordshire, and Augustin Ley, Vicar of Sellack and 
King’s Capel, Herefordshire. 8vo, 21s. Hereford : Jakeman and 
Carver. 
Few works are more interesting to the botanist than a reliable and 
well-compiled Flora of a district. To possess these characteristics it 
should proceed from those having a practical knowledge of our native 
plants, judgment to discriminate species from sub-species, and 
native plants from aliens, casuals, and the like. If, in addition to this, 
special features in the habit and distribution of the plants are given, it 
will add to our knowledge and materially increase the interest of the 
