Fig. 10. 
Mr. A. Adams on new Mollusca from Japan. 331 
the inner, ccc, represent the section of the netted cylinder ; 
6, origin of a rootlet. 
Cross section of the rhizome of Lastrea Oreopteris, somewhat fore- 
shortened, with a portion of a petiole attached, showing the con- 
verging tracts of dark tissue, a. 
- Section of the rhizome of Lastrea dilatata along the axis, showing 
the fusiform dark nodules in the medullary tissue: a a, fasciculi 
of the netted cylinder in section. 
. Cross section of a petiole of Asplenium Ruta muraria near the 
base ; 
PLATE VI. 
- Section of the petiole of Scolopendrium vulgare, along the axis, 
showing the course of the dark tracts, like two converging lines 
of railway. 
. Cross section of the same, a little ilinee the base. 
. Cross section of the same, about the commencement of the lamina 
of the frond. In the small fronds of Ceterach officinarum the 
arrangement is somewhat similar. 
. Cross section of the petiole of Athyrium Filizx femina at the base. 
. Cross section of the rhizome of Hymenophyllum Wilsoni, showing 
the brown cortical and pale medullary tissue, with the single 
vascular fasciculus imbedded in the latter. 
. Cross section of the rhizome of Allosorus crispus, showing the 
central dark cord, and the sheaths round the fasciculi of the netted 
cylinder. 
. Cross section of the rhizome of Pteris aquilina, showing the outer 
and inner series of vascular fasciculi, the two intermediate dark 
bands, and the extremities of some of the longitudinal dark fila- 
ments. 
. A corresponding section of the base of the petiole. 
. Cross section of the petiole of Polypodium alpestre above the point 
of junction of the two lateral fasciculi. The section below this 
point is nearly as in fig. 4. These two figures would also repre- 
sent in some degree the arrangement in Lastrea Thelypteris, if 
the fasciculi were surrounded by a coat of dark tissue. 
Cross section of the petiole of Lastrea cristata near the base. 
There is a similar arrangement in Polystichum aculeatum, 
Lastrea Filiz mas, and L. dilatata, and also, with the exception 
of the dark sheaths, in Polystichum Lonchitis. 
The magnifying power is marked beside each figure. 
XLII.— On some new Genera and Species of Mollusca from Japan. 
By Artuur Apams, F.L.S., &c. 
Genus Zarra, A. Adams. 
Testa acuminato-ovalis utrinque angustata, in medio tumida ; anfrac- 
tibus longitudinaliter plicatis, ultimo ad basin constricto. Apertura 
linearis, angusta ; labio effuso, margine externo libero; labro mar- 
gine 
acuto, postice subsinuato, in medio recto, subinflexo. 
This little shell will constitute the nucleus of a group of Tur- 
ride, of which several from deep water have been described by 
D’Orbigny, and figured, I believe, in the last plate of Reeve’s 
22* 
