whole hypothesis. This illustrious conchologist relates that he had an opportunity of examining the immense fecundity of the sessile barnacles. In the beginning of June he found innumerable aggregations of them, covering certain boats that had been long stationary, which, when closely examined, were so minute, that single shells were not bigger than the point of a needle; and that, from that time, they grew very rapidly, and arrived at their full size in October." These very minute ors must have been hatched from the egg, and not produced from larves. With regard to the functions and instincts of these Cirripedes, very little has been observed. We see from the above account of them, that, like many other animals amongst the kwest grades of the animal kingdom, they are furnished with particular organs adapted to the capture of animalcules and her minor inhabitants of the deep, which they help to keep win due limits. Probably they act upon the substances to wch they attach themselves, and promote the decomposition of shells, and other exuviæ of defunct animals, and also of the reas and ligneous substances on which they take their station. Of this we are sure, that they work His work who gave them te..g, and assigned them their several stations in the world of waters. CRINOIDEANS. In the deepest abysses of the ocean, it is probable, lurks a true of plant-like animals, to judge from its numerous fossil "aas, abounding in genera and species that are very rarely seen in a recent state, and which, from a supposed resemblance between the prehensory organs or arms, surrounding the head of mouth of several species belonging to the tribe, when their extremites converge, to the blossom of a liliaceous plant, have bren denominated Encrinites and Crinoïdeans.1 It was not my argnal intention, as little or nothing was known with respect to the habits and station of the few recent ones that have been met with-except that one has been taken in the seas of Eurge, and three in the West Indies, namely, near Martinique, Barbados, and Nevis-to have introduced them into the present work, but having subsequently seen fragments of a specimen, taken either in the Atlantic or Pacific, I am not certain wch, and, upon examining it under the microscope, finding 1 From xpo a lily. evident traces of suckers on the underside of its fingers, and of the tentacles that form its fringes,' a circumstances I found afterwards mentioned by Ellis, and which throws some light upon their economy, I felt that I ought not to pass them wholly without notice, and finding in the Hunterian Museum a very fine specimen which does not appear to have been figured, for the figure given by Ellis seems to have been taken from Dr. Hunter's specimen, now at Glasgow, and Mr. Miller's from a specimen of Mr. Tobin's, now in the British Museum, by the kind permission of the Curators of the Museum in Lincoln's Inn Fields, I was allowed to have a figure of it taken by my artist, Mr. C. M. Curtis." Lamarck has placed the Crinoïdeans, led, probably, by their plant-like aspect, in the same Order with his Floating Polypes, not aware that the majority are evidently fixed, but Cuvier and most modern zoologists consider them, with more reason, as forming a family of the Stelleridans, from which the way to them is by the genus Comatula, remarkable for its jointed rays fringed on each side. The Marsupites, as Mr. Mantell, after Mr. Miller, has observed, form the link which connects the proper or pedunculated Crinoïdeans with the Stelleridans. If we compare them again with the class last described, the Cirripedes, especially the Lepadites, we shall find several points which they possess in common. In the first place, both sit upon a footstalk-though of a different structure and substance; the animal in both, in its principal seat, is protected by shelly pieces or valves; the head or mouth, in both, is surrounded by dichotomizing articulated organs, involuted, and often converging at the summit, and fringed on each side, in the Crinoïdeans, with a series of lesser digitations, and in the Cirripedes with a dense fringe of hairs. If the opinion of Mr. W. S. Mac Leay, stated above, that some of the Echinoderms exhibit an approximation to some of the Cirripedes, is correct, as it seems to be, the Crinoideans, though still far removed, would form one of the links that concatenate them; or if their connection is thought merely analogical, the Balanites would be the analogues of the Echinidans and of the sessile Crinol deans, and the Lepadites of the pedunculated ones. The following characters distinguish the Pentacrinites, to which Tribe all the known recent species belong. Animal, consisting of an angular flexible column, composed of numerous joints, articulating by means of cartilage, and 1 PLATE III. B. FIG. 2. 3 Polypi natantes. 2 Ibid. FIG. 1. perforated for the transmission of a siphon or intestinal canal, and sending forth at intervals, in whorls, several articulated cylindrical branches, curving into a hook at their summit; fixed at its base, and supporting at its free extremity a cup-like body, containing the mouth and larger viscera, consisting of several pieces, terminating above in five (or six) dichotomising, articulated, semi-cylindrical arms, fringed with a double series of tentacular jointed digitations, furnished below on each side with a series of minute suckers; these arms, when expanded, resemble a star of five (or six) rays, and when they converge, a pentapetalous or hexapetalous liliaceous flower. The whole animal, when alive, is supposed to be invested with a gelatinous muscular integument. In the specimen figured by Mr. Ellis, and that in the Hunterian Museum, there appear to be six arms springing from the so-called pelvis, but the natural number appears to be five, corresponding with the pentagonal column. Mr. Miller seems to be of opinion that the species described by M. Guettard, and that which he has himself figured, are the same species, and synonymous with the Isis Asteria of Linné and the Encrinus Caput Medusa of Lamark, but to judge from the figures of the first in Parkinson,' and of the other in Miller, compared with that which is given in this work, the last seems to differ from both, as well in the pelvis as in the dichotomies, and length of the arms; its suckers likewise appear to be circular, and not angular as they are described by Mr. Miller under the name of plates. If this observation turns out correct, I would distinguish the last species by the name of Pentacrinus Asteria. The stem of the Crinoideans consists of numerous joints, united by cartilages, which exhibit several peculiarities; in the first place, the upper and under side is beautifully sculptured, so as to represent a star of five rays, or a pentapetalous flower; the Creator's object in this structure appears to be the attachment of the cartilage that connects them, and, perhaps, to afford means for a degree of rotatory motion, as well as to prevent dislocations, and also to increase the flexure of the stem according to circumstances, and the will of the animal: for the transmission of the siphon, whether a spinal chord or intestinal canal, or both, each joint of the column is perforated, the aperture being round in some, and floriform in others. The whole stem, with its whorls of branches, exhibits a striking 1 Organic Remains, ii. t. xix. f. 1. 5. Ubi supr. 54. t. ii, ƒ. 6. 2 Crinoidea, 48. t. 1. 4 Ibid. FIG. 2. resemblance to the branch of the common horse-tail. The entire structure seems calculated to enable the animal to bend its stem, which appears very long, in any direction, like the Lepadites, and thus, as it were, to pursue its prey; we may suppose that the branching arms, fingers, and their lateral organs, when they are extended horizontally and all expanded, must form an ample net, far exceeding that of the Cirripedes, which, when they have their prey within its circumference, by converging their arms, and closing all their digitations, and employing their suckers, they can easily so manage as to prevent the escape of any animal included within the meshes of their net. With regard to their functions, and what animals their Creator has given a charge to them to keep within due limits, little can be known by observation; as nothing like jaws have been discovered in them, in which they differ from the Cirripedes, it should seem that either their food must consist of animalcules that require no mastication, or, if they entrap larger animals, that they must suck their juices, which seems to be Mr. Miller's opinion. This idea is rendered not improbable by the vast number of suckers by which their fingers, and their lateral branches, or tentacles, as they are called, are furnished; by these they can lay fast hold of any animal too powerful to be detained in their net by any other means, and subject it to the action of their proboscis. From the great rarity of recent species of these animals, it should seem that the metropolis of their race is in the deepest abysses of the world of waters. "It appears," says Bosc, "that the species were extremely numerous in the ancient world; perhaps those actually in existence are equally so, for I suspect that all inhabit the depths of the ocean, a place in which they may remain to eternity without being known to man." Naturalists very often, too hastily, regard species as extinct, that are now found only in a fossil state, forgetting that there may be many stations fitted for animal or vegetable life, that are still, and, perhaps, always will be, inaccessible to the investigator of the works of the Creator, where those mourned over, as for ever lost, may be flourishing in health and vigour, 2 Crinoidea, 54. 1 Equisetum arvense. 3 N. D. D'Hist, Nat. x. 224. CHAPTER XIV. Functions and Instincts. Entomostracan Condylopes. We are now arrived at a great branch of the animal kingdom, which, in its higher tribes, exhibits Divine Wisdom, acting, in and by the instincts of creatures, small indeed in bulk, but mighty in operation, in a way truly admirable, indicating, in a most striking manner, the source from which it proceeds. Some modern zoologists do not regard this vast and interesting branch as forming a group by itself, but have associated with it, under a common name, several of the preceding classes. Carus in his Class of Articulated Animals, includes Damarck's Worms and Annelidans; and Dr. Grant, in his Subkingdom, bearing the same appellation, adds to these the Wheelanimalcules, and Cirripedes." I cannot help thinking, however-taking the whole of their organization and structure into consideration, particularly their powers and means of locomotion and prehension-that it is best to regard those animals having jointed legs, and, mostly, a body formed of two or more segments, as constituting a separate Sub-kingdom. This is the view that my late illustrious and lamented friend, Latreille, has taken of this great group, named by him, from the above circumstance, Condylopes, which term, since that of Annulose animals, sometimes used, is synonymous with Annelidans, I shall adopt in the present work. The distinctive characters of this great group, or Sub-kingdom, may be given in a few words: ANIMAL, not fixed by its base, but locomotive. Body, in the great majority, consisting of two or more seg ments. Legs, jointed. The first of these characters distinguishes the Condylopes from the last class, the Cirripedes, which are fixed by their base, whereas the present tribe are more free in their motions than most of the animals of the preceding groups; and the two last 2 Rotifera. 1 Articulata 3 Cirrhopoda, 5 Annulosa. |