Catophragnu, G. B. Sowerby.—Compartments eight, with several exterior whorls of small supplemental compartments; basis either membranous or calcareous.
"The shell," says Mr. G. B. Sowerby, "consists in a number of narrow perpendicular valves arranged around the shelly cone, and in rows, like pales, the first row of which consists of eight pieces, placed so as exactly to cover the sutures of the mildly cone immediately surrounding the animal; around this are then placed several seta of more and more numerous pieces gradually decreasing in size, so that the outer row, which is the most numerous, consists also of the smallest pieces. Additional rows seem to be produced as the animal increases in age ; for a young specimen in our possession has only one row of eight pieces covering the sutures of the first cone, while a much larger and older specimen still retains part of three rows, and has evidently lost some of the external rows. The young individual also shows that the whole of the pieces are pointed at their superior extremities, whereas in the old shell these extremities are so worn or eroded as to become very irregular and obtuse." Family IL— rerrucidc.
Cirripedia without a peduncle ; acute and terga not furnished with depressor muscles, moveable only on one side, on the other side united Immoveably with the rostrum and carina into an asymmetrical shell.
Family 111.—Lepailidie.
Cirripedia having a flexible peduncle, provided with muscles ; scuts and terga (when present) not furnished with depressor muscles ; other valves (when present) not united into an immoveable ring.
The genera of this family affix themselves by means of their peduncle to submarine bodies, forming numerous groups. They are often found on floating substances far at sea : on ships, on logs of timber, on bottles, on net-corks, on foci, on floating testaceous mollusks, lanthina for instance, and even on some of the vertebrated animals, on whales, turtles, and even serpents — //ydrorhis, for example. Other testaceous mollusks might be mentioned, and one species has been found parasitical within the umbrella of a Medusa. A large log of timber covered with these animals, twisting
and diverging in all directions, and so thick as entirely to hide the surface of the log, is a strange sight. They look like an enormous collection of serpents to the ignorant; and we have heard a living mass of this description casually thrown into shallow water and left by the tide so termed. Their growth must be extremely rapid. A ship going out with a perfectly clean bottom will often return from a abort voyage covered with them below the water-line. The Blacks of Gores are said to eat a large species of Pentalasmii, which is stated to be delicate.
Lepas.—Valves 5, approximate ; carina extending up.between the terga, terminating downwards in an imbedded fork or in an external disc ; 'scuta subtriangular with their umbones at the rostra' angle. The species are found all over the world attached to floating objects.
L. anattfera, the Common Barnacle. It is the Anatifa, Anatifera, and Pcntalasmia of many authors. Anatife engonata of Conrad ; A. dentate (var.)of Bruguieres; Peniala.mia dentatur of Brown; A nat tfe of Martin-Saint-Ange. The valves are amooth or delicately striated. Right hand senturn alone furnished with an internal umbonal tooth ; uppermost part of peduncle dark-coloured. It is extremely common, attached to floating timber, vessels, sea-weed, bottles, Sc., and to each other.
Mr. Darwin describes also the following species :—L. Huai, L. anseri fere, L. pectinate, L. auatralis, L. fascicularis.
Peeeilaania, Darwin.—Valves 3,5, or 7, approximate ; carina extend ing only to the basal points of the terga, with its lower end either truncated or produced into a deeply imbedded disc. Scuts. nearly oval, with their umbones at the rostral angle. This genus embraces the following species Kompferi, P. aurantia, P. crease, P. Arse, P. eburneu. Four out of the 'five species live attached to Orustacea in the European and Eastern warmer, temperate, and tropical oceans. The fifth species was found attached to the dead species of an off New Guinea. It is probable that several more species may be discovered.