17 
British species of the genus Lagena. 
2. Entosolenia marginata, PL II. figs. 15, 16. 
Serpula (Lagena) marginata. Walker, p. 3. tab. 1. fig. 7. 
Vermiculum marginatum^ Mont. p. 524. 
Lagenula marginata, Thorpe. 
Cell nearly orbicular, compressed, transparent or translucent, 
especially in a young state, having a slight projection at the upper 
extremity, towards the end of which is the orifice communicating 
with the internal tube. The cell is surrounded by a thin marginal 
lamella, which is continued as far as the oral orifice ; within this 
margin, in old shells, is occasionally a thickened opake portion 
shaped like a horse-shoe, with the concavity and interrupted part 
directed upwards, the circumscribed central portion being more 
transparent. The lower extremity of the cell is sometimes fur- 
nished with a small external mucro. The internal tube, which 
is somewhat patulous, is rarely straight, except at the upper por- 
tion, the remainder being usually arcuated, following the curva- 
ture of one of the lateral parietes of the cell. Fig. 15 represents 
a section of the cell, with the tube cut across where the curvature 
commences. 
This is the most common of our English species. At the Fal- 
mouth habitat it was comparatively abundant, adhering to a spe- 
cies of Antennularia, along with young forms of Polystomella 
crispa^ Rosalina globularis and some others. 
The L. marginata of Dr. Fleming is a concamerated shell ; the 
Rimula marginata of some authors, and belonging to D^Orbigny^s 
genus Biloculina. 
Long. Diam. 
100 • • • • 110 
1 1 
1 'B'Tr • • • • ^14- 
_ 1 _ _1 
200 • • • * 2 lU 
Swansea, Eossilly, Manorbeer, Portsmouth, Sandwich, Oban, 
Kyleakin, Mr. Jeffreys. Scarborough ; Lamlash Bay, Ayrshire ; 
Mr. Bean. Reculver,^^ Walker. Boston, March, Falmouth, 
the Levant. 
E. marginata, var. lucida, nob. PI. II. fig. 17. 
Cell elongated, somewhat pyriform, compressed, smooth and 
shining, surrounded by a marginal ring, which instead of being 
a thin lamina as in the ordinary type, is usually thickened and 
somewhat rounded. It is occasionally scarcely visible, especially 
towards the base, where however it often projects in the shape of 
a mucro. This margin, with the upper and central portions of 
each of the lateral parietes, are generally transparent, whilst the 
remainder of the cell is usually of a clear shining white ; internal 
tube generally straight. 
I was much disposed to have regarded this as a distinct spe- 
Ann. ^ Mag, N, Hist, Ser. 2. Vol. i. 2 
