Natural INstory of East Finmark. 93 
to thoroughly understand the way in which C. nitido-punctata 
assumed its unusual form, and this led on to the examination 
of the entire family. _ 
Nitida (Pl. VIII. fig. 8).—Three bars are here represented. 
It will be observed that they are of irregular form, the exact 
character of which is decided by the necessity of forming 
distal junction with their collateral and opposite neighbours : 
the line of junction in this particular species has a waved 
zigzag character. The bar at its commencement in the side 
wall is a rounded loop. This is the first point of great 
importance to note because the existence of such a loop in the 
side or front wall of auu Cribriline leads us to understand the 
building up of the zocecium in some obscure cases. The 
second point of primary importance is the presence of a very 
large lumen, which here occupies the whole of the interior 
of the bar. In some forms we find that this lumen is only 
indicated by a fine central line, or by the presence in that 
line of a minute pore; or all trace of it may be obliterated 
by the overgrowth of a rib, which is raised over the lumen- 
line. 
Melolontha (Pl. VIII. fig. 9).—The character of the bars is 
similar to that of nitida. In the first bar which is drawn 
there will be noticed a tendency of the lumen to divide and 
form a fork. In other species it will be found that this is 
carried further. 
Annulata (P1. VIII. fig. 10).—The figure given is drawn 
from an unusually simple form of the species * living on a 
frond of Luminaria, but has some special characteristics. 
The bars are only loosely attached and not cemented together; 
and on boiling in liquor potassz the zocecium in many cases 
broke up, the bars separating. The lacunes between the bars 
in the zocecium illustrated are the result of the simple 
contact of two bars here and there, and each bar retains its 
own strongly marked margin; and thus we have the earliest 
and simplest mode of formation of these lacunes,in the producing 
of which two bars always take part. The bars themselves, 
which in this specimen are more flattened than usual, have 
the appearance, at first sight, from their opacity and brownish 
colour, of being solid; but closer inspection reveals a pellucid 
circle in the Joop of the bar within the marginal line of the 
zocecium which indicates the end of the lumen, while at the 
distal end of many of the bars there is a small pore, and the 
conviction becomes almost a certainty that a lumen fills the 
whole bar except the narrow marginal line. The ordinary 
* Kindly given me by Dr. Harmer; he procured it at Goddsand, off 
Tysnasd in Bjorne Fiord, Norway. 
