CONTIGUOUS. (_Contingo_, to touch.) A term applied to the whorls of spiral shells when they rest upon, or touch each other. This is the case in a great majority of instances. When, on the contrary, there is a space between the whorls, they are said to be non-contiguous, detached, or free. Examples of non-contiguous whorls are to be seen in Scalaria, fig. 351 (in this case, the distance between the whorls is small), and in Crioceratites, fig. 482. A "_Columella contiguous to the axis_," is when in the centre of the shell and takes the place of the imaginary line which forms its axis. CONTINUOUS. Carried on without interruption, as the siphon in Spirula, the varices in Ranella, fig. 394, which, occurring in a corresponding part of each whorl, form a continuous ridge. CONULARIA. Miller. A genus of Orthocerata, described as conical, straight, or nearly so, divided into chambers by imperforate septa; aperture half closed; apex solid, obtuse; external surface finely striated. Resembling Orthoceras, but wanting the siphon. Fig. 449. CONUS. Auct. ([Greek: Kônos], a cone.) _Fam._ Enroulées, Lam. Angyostomata, Bl.--_Descr._ Conical, convolute, with a short spire, consisting of numerous whorls; and narrow lengthened aperture, terminating in a slight emargination at each extremity; outer lip thin; epidermis thin; operculum small, pointed, horny.--_Obs._ This well-known genus of shells is easily distinguished from any other, by its conical form, its smooth columella, its narrow aperture, and thin outer lip. The form of the spire varies from flat and even partially concave, to a regular pyramidal cone; and the upper edges of the whorls are rounded in some species, angulated in others, and in some are waved or coronated. The variety of marking and the numerous delicate tints of these shells have caused them to be highly appreciated by amateur collectors; and many species, as the C. Ammiralis, or admiral; the C. Gloria Maris, or Glory of the Sea; the C. Cedonulli ("I yield to none"), and others, have always produced good prices in the markets. We give figures of the principal forms, as expressed in the genera proposed by De Montfort, of Rhombus, Hermes, Rollus and Cylinder, in figures 459 to 462. Many new species were brought to this country by Mr. Cuming, and are represented in parts 24, 25, 28, 29; 32, 33, 36, 37; 54, 55, 56, 57; 147, 148; 151 to 158 of the Conchological Illustrations, by G. B. Sowerby, jun. See CORONAXIS, Swainson. The cones are mostly tropical, some are found as far north as the Mediterranean, and south as the Cape of Good Hope. The most beautiful species are from the East and West Indies. CONVOLUTÆ. (Enroulées, Lam.) A family of the 2nd section of the order Trachelipoda, Lam. the genera of which may be distinguished as follows:--