15 
British species of the genus Lageria. 
Manorbeer near Tenby, very rare, Mr. Jeffreys. Scarborough, 
one specimen, Mr. Bean. Boston. 
Lagena striata, perlucida. PL I. fig. 11. 
Cell usually globular, sometimes broadest at the base, at others 
ovate. Marked with longitudinal costse, which are very distinct 
at the lower portion, but gradually lose themselves as they ap- 
proach the long, elegant, tapering neck. In this it differs from 
the last var., in which the stride terminate abruptly at the upper 
part. Cell exceedingly thin and fragile, beautifully hyaline and 
pellucid, sometimes of a pale milky tint, but more commonly 
transparent as the purest glass. 
I believe this to be the Vermiculum perlucidum of Montagu : his 
figure represents a highly depressed form of cell, furnished with 
a small umbo at the base ; but as Montagu had never seen the 
specimen, but only copied a drawing sent to him by Mr. Boys, I 
suspect that some error exists. I have often seen the projecting 
base of the central costa give the appearance of an umbo, and'as 
regards form I have observed very great differences. The number 
of the ribs varies considerably. Some specimens, like Montagues 
V. perlucidum, have not more than seven or eight, whilst in others 
they increase in number so as to merge this variety in the ordi- 
nary forms of L. striata, of which species I believe it to be one of 
the young states. Its most common aspect is precisely that of 
the ordinary fluted water-bottle used at the dinner-table. Some- 
times the strise are so short and indistinct as to render the spe- 
cimen almost undistinguishable from L. lavis ; indeed in some 
few specimens the striae are only represented by'^ a small circle of 
minute tubercles forming a coronal at the base of the cell. 
Long. 
Diam. 
1 
eV • • • 
• 12 0 
1 
1 
8 8 • • * 
* 1 85 
1 
1 
1 1 0 • • • 
• 2 4 0* 
Swansea, Tenby, Manorbeer, Sandwich, Kyleakin, Mr. Jeffreys. 
Seasalter, Mr. Boys.^^ Montagu. Boston ; March. 
4. L. substriata, nob. PI. II. fig. 12. 
Cell oval, sometimes considerably elongated and cylindrical, 
furnished with a long tubular neck. Surface marked with nu- 
merous exquisitely delicate parallel longitudinal striae. 
At first I thought that this rare object was an extreme variety 
of Lagenula striata, but after examining at least twenty specimens 
I am nearly satisfied that it is a distinct species, as the lines vary 
so little either in their number, strength, or distance apart. The 
general form of the cell also is much more ovate and elongated. 
