PROF. WYVILLE THOMSON had not set foot long in Old England before presenting in person a preliminary quota of his results to the learned bodies. Two papers read by him at the Linnean Society on June 1, embodied observations on Echinodermata, a group to which, as is well known, he previously had paid much attention. One of the communications described some new living Crinoids belonging to the Apiocrinidæ. Of deep-sea forms the stalked crinoids are extremely rare, and have a special interest on account of their palæontological relations; it was therefore with satisfaction that near St. Paul's rocks at 1,850 fathoms, the trawl brought up, among other things, an entire specimen of a new crinoid, Bathvcrinus Aldrichianus, and fragments of another, Hyocrinus bethellianus. At other stations and on different occasions, were obtained another species of Bathycrinus (B. gracilis) and an undetermined beautiful little species of Hyocrinus, besides examples of the Rhizocrinus lofotensis of Sars; all of these being referable to the Apiocrinidæ. In pointing out their structural peculiarities and alluding to Bathycrinus, he mentioned that the stem barely enlarges at its junction with the cup, the ring formed by the basals is very small, and the first radials are free from the basals and often free from one another, while the oral plates are absent. This genus appears to possess an assemblage of characters in some respects intermediate between Rhizocrinus and the pentacrinoid stage of Antedon. Hyocrinus bethellianus has much the appearance, and in some prominent particulars it seems to have very much the structure of the palæozoic genus Platycrinus or its sub-genus Dichocrinus. The stem is much more rigid than that of Bathycrinus; the cup consists of two tiers of plates only, the lower is to be regarded as a ring of basals, and the upper consists of fine spade-shaped radials. There are five arms wnich are pinnulated. The proximal pinnules are very long, running on nearly to the end of the arm, and the succeeding pinnules are gradually shorter, all of them, however, running out to the end of the arm. Distally the ends of the rive arms, and the ends of all the pinnules meet nearly on a level. This arrangement is unknown in recent crinoids, although we have something close to it in species of the fossil genera Poteriocrinus and Cyathocrinus; with this, however, their resemblances end. Rhizocrinus finds its ally in the cretaceous genus Bourgueticrinus; Bathycrinus and Hyocrinus are evidently related to the former, but the characters of the Apiocrinidæ are nevertheless obscure in the two latter. In his second paper Prof. Wyville Thomson drew attention to peculiarities in the mode of propagation of certain Echinoderms of the Southern Sea. He passed in review examples of the Sea-cucumbers (Holothuroids), Sea Urchins (the circular Cidaroids, and heart-shaped, Spatangoids), Star-fish (Asteroids), and the Brittle Stars (Ophiuroids). In allusion to their phases of development he stated the majority of these pass from the egg without the intervention of a locomotive pseudembryo. Among other data in support of this view he said, that while in warm and temperate seas “plutei” and “bipinnari” were constantly taken in the surface-net; yet during the southern cruise between the Cape of Good Hope and Australia, only one form of Echinoderm pseudembryo occurred, and which was considered with some little doubt as the larva of Chirodota from the presence of dermal, calcareous, wheel-shaped spicules; Furthermore Prof. Wyville Thomson described in detail the almost constant occurrence among the majority of the foregoing groups a curious, receptacular pouch wherein the young are carried until arriving at a certain maturity. This marsupium is situated on the dorsal portion of the body, is composed of a series of plates which meet centrally arid permit of the young creeping about and returning to it for shelter. The young derive no nutriment from the parent while contained in the “nursery,” other than it may be a mucous secretion.