10 FOSSIL CIRRIPEDIA. 
justified in giving short names to each of the more important valves, these being common 
to the Pedunculated and Sessile Cirripedes. 
The title of peduncle, which is either naked or squamiferous, requires no explanation ; 
the scales and lower valves are arranged in whorls, which I have called by the botanical 
term of Verticillus. The part supported by the peduncle, and which is generally, though 
not always, in recent species protected by valves, I have designated the Capitulum. 
I have applied the term Scutum to the most important and persistent of the valves, and 
which can almost always be recognised by the hollow giving attachment to the adductor 
scutorum muscle, from the resemblance which the two valves taken together bear to a shield, 
and from their office of protecting the front side of the body. From the protection afforded 
by the two Zerga to the dorso-lateral surface of the animal, these valves have been thus 
called. The term Carina is a mere translation of the name already used by some authors, 
of Keel-Valve: in the genus Scalpellum, in which this valve is taken as typical, I have 
found it quite necessary, with fossil specimens, to distinguish the roof (see Woodcut, I,) 
or exterior surface, as the tectum (A); the inflected sides, as the parietes (B); and in 
several species in the upper half of the valve, the intra-parietes (C): the expressions of 
apex, basal margin, and inner margin, as applied to the Carina, require no explanation. 
The rostrum has been so called from its relative position to the Carina or keel. ‘There is - 
often a swb-carina and a sub-rostrum. 
The remaining valves have been called Zatera; there is always one large upper one 
inserted between the lower halves of the Scuta and Terga, and this I have named the Upper 
Latus or Latera; the other Latera in Pollicipes are numerous, and require no special 
names ; in Scalpellum, where there are at most only three pair beneath the Upper Latera, 
it is convenient to speak of them (vide Woodcut, I,) as the Carinal, Infra-median, and 
Rostral Latera. 
As each valve, especially amongst the fossil species, requires a distinct description, I 
have found it indispensable to give names to each margin. ‘These have mostly been 
taken from the name of the adjoiming valve, (see Woodcut, I.) In Pollicipes the margin 
of the Scutum adjoming the 'Tergum and Upper Latus, is not divided (Woodcut, IT,) into 
two distinct lmes, as in Scalpellum, and is therefore called the tergo-lateral margm ; a 
narrow portion or slip along this side of the valve may be seen (Woodcut, II,) to be formed 
of upturned lines of growth; this is often of service in classification, and I have called it 
the tergo-lateral slip or segmentum tergo-laterale. In Scalpellum (Woodcut, I,) these two 
margins are separately named Tergal and Lateral. The angle formed by the meeting of 
the basal and lateral or tergo-lateral margins, I call the baso-lateral angle; that formed by 
the basal and occludent margins, I call, from its closeness to the Rostrum, the rostral 
angle. In Pollicipes the Carinal margin of the Tergum (Woodcut, III,) can be divided into 
an upper and lower Carinal margia. 
That margin in the Scuta and Terga which opens and s/wfs for the exsertion and 
retraction of the cirri, I have called the Occludent margin. 
