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abundant , ; and these, with very few exceptions, have the 
costse passing- forward to the extremity of the neck, in which 
case it is only one half of the whole number which do so, each 
alternate one stopping short at the base. Specimens where 
the costae wind spirally around the neck are equally common 
with those in which they take a straight course. These 
Lagenae have the appearance of old coarse shells, but they do 
not seem to have suffered from attrition ; they are scarcely 
ever found with the neck broken short, though it may perhaps 
be almost equally rare to meet with one absolutely perfect. 
The varieties — clavata, perlucida, semistriata, and substriata, 
are comparatively rare, and all of them have forms and charac- 
ters very distinct from striata and interrupta, while the two 
latter -agree perfectly excepting in the matter of the costse, 
which are found in different specimens to be interrupted in a 
great variety of ways, those with the costse perfectly con- 
tinuous being the least common ; so that the conclusion I am 
inclined to come to is, that they need not be separated even 
as varieties, and that, whatever doubts may remain as to some 
of the other named varieties, the great abundance of these two 
and the constancy of their general characters make it certain 
that together they will form a good species under the name 
of Lagena striata. A few specimens of this species have a 
macro at the base, and deformed ones are not uncommon ; 
these, besides having the body variously mis-shapen, often 
have the neck bent, sometimes even so much as to give the 
specimen the form of a retort. 
The Dogs Bay sand contains many forms of hntosolenia, 
some of them agreeing with those described by Professor 
Williamson, but others distinct ; and of these latter I have 
ventured to name two, which may be described as follows: — 
1. Entosolenia Williamsoni, a very abundant form, might 
pass at first sight for Lagena striata with the neck broken 
away, but a close examination shows it is a perfect shell, the 
body like L. striata but rather less full in proportion to its 
e 
