408 PYRAMIDELLID&. 
species it is often strong, slender, small, prominent and re- 
tired. Such characters cannot fail to mislead and confuse 
the young student. 
The first and best characters of a Chemnitzia are undoubt- 
edly the malacological ones we have given above, when they 
can be had; the next are of conchological value, the inflected 
apices; which however will almost always shadow out what 
the animal of a shell will prove; and the tooth, however 
minute and rudimental, is an excellent aid; and we may add, 
the flap or process of the operculum. All others, from their 
instability, lead to error and confusion ; but if they are brought 
forward as specialties, it should be sub modo, with explanatory 
guards and limits, and indications of their variableness. 
I now approach the catalogue raisonné, and will include 
with it the additions and new matter under the titles to which 
they belong. Perhaps it may be conceded that a sedulous 
examination of these interesting objects for more than forty 
years, has in some measure placed me in a position to offer a 
reformed list of the British Chemnitzie, which will include all 
the animals, with our defined characters, whatever may be the 
form and sculpture of their testaceous habitations. To accom- 
plish what I have proposed, my own cabinet affords large 
facilities, and my friend Mr. Barlee has kindly taken the 
great trouble to consign to me for mspection, from Falmouth, 
his rich tablets of accredited examples of those species I do 
not possess. These aids and appliances have mereased my 
confidence that perhaps I may succeed in offering such a 
relieved and moderated list of the objects of this important 
genus, as will place within just limits the genuine indigenous 
Chemnitzie of our Isles. We do not pretend to periorm this 
task without error. Who, on such a subject, can avoid occa- 
sional misconceptions? We can only try conscientiously to 
perform our duty; but, alas! even in the midst of these de- 
lightful studies and recreations, the bit of bitter will spring 
up. How admirably has the inimitable Lucretius illustrated 
this inevitable ingredient in all human affairs, and told us 
that the attempt to evade the thorns of this destroyer on our 
peace is vain and fruitless !— 
