20 
Mr. W. C. Williamson on the genus Lagena. 
sometimes straight and at others arcuated. This form is merely 
the E. squamosa with the areolae in perpendicular rows instead of 
being irregularly distributed over the surface. Sometimes these 
areolae exhibit a tendency to assume the ordinary white opake 
appearance of the common form. I have seen specimens in which 
one side exhibited the arrangement in fig. 19, and the opposite 
one that of fig. 20 ; thus showing the identity of the two forms. 
Long, diam. xii- 
Swansea, Sandwich, Mr. Jeffreys. Boston : very rare. 
Entosolenia squamosa, var. /3. scalar if ormis, nob. PI. II. figs. 
21 , 22 . 
Closely resembling the last in the distribution of its areolae, 
only they are very large and few in number ; usually square or 
hexagonal, the horizontal lines of division being most frequently 
a little arcuated. The texture of this variety is highly hyaline, 
and commonly occurs amongst the young states of E. squamosa. 
As in the preceding example, I have seen specimens in which 
one side exhibited the arrangement of the areolae, characterising 
the present form, whilst the opposite one presented that of the 
succeeding variety. 
Long. Diam. 
1 UO • • • * 144. 
• • • • 2UT) 
Kyleakin, Mr. Jeffreys. Lamlash Bay, Ayrshire, Mr. Bean. 
Boston ; March : very rare. 
E. squamosa, var. 7. hexagona. PI. IT. fig. 23. 
Areolae large, hexagonal, concave, not arranged in well-marked 
perpendicular rows. The cell is often more conical, opake, and of 
a browner aspect than in the other forms, but numerous interme- 
diate specimens link them all together, both as regards the colour, 
form and arrangement of the areolae. 
Long, xft; diam. 
Oban, Kyleakin, Mr. Jeffreys. Lamlash Bay, Scarborough, 
Mr. Bean. Boston ; March : very rare. 
The Vermiculum lacteum of Montagu is not a Lagena, but the 
Arethusa lactea of Fleming, a species of Pohjmorphina of D’Or- 
bigny. Vermiculum retortum, Mont., is a very young state of one 
of D^Orbigny^s family of Agathistegues, probably the Vermiculum 
hicorne, Mont. Vermiculum urnce of Montagu, as I have already 
stated, I believe to be the same as my Entosolenia lineata. Mr. 
Jeffreys suspects it to have been the ovary of a coralline. The 
Lagenula marginata of Fleming belongs to D^Orbigny^s genus 
Biloculina. 
Manchester, June 25, 1817. 
