ARTICULATED. (Jointed.) Applied to distinct parts of shells, which are fitted or jointed into each other, as the valves of Chitones and those of Balani. The operculum of Nerita is said to be _articulated_ to the columella, having a small process by which it is as it were locked under the edge. See _Introduction_. The word is also applied to the Cirri, which protrude from the oral openings of Cirripedes. ARTICULINA. D'Orb. A genus of microscopic Foraminifera. ASIPHONIBRANCHIATA. Bl. The second order of Paracephalophora Dioica, Bl. Consisting of spiral univalves, which have no notch or canal at the anterior part of the aperture. This order is divided into the families Goniosomata, Cricosomata, Ellipsostomata, Hemicyclostomata, and Oxystomata. ASPERGILLUM. Lam. (From _Aspergo_, to sprinkle.) _Fam._ Tubicolæ, Lam. Pyloridea, Bl.--_Descr._ The small, equal, equilateral valves are cemented into, so as to form part of, a large tube; the umbones are slightly prominent outside. The tube is elongated, rather irregular, granulated with sandy particles, and terminated at the base by a convex disc, which is perforated by small pores, elongated into tubes round the edge, presenting a resemblance to the spout of a watering pot, whence the name is derived. _Loc._ New Holland, Java, New Zealand, Red Sea. Fig. 44. Aspergillum Vaginiferum. ASSIMINEA. Leach. _Fam._ Turbinacea, Lam.--_Descr._ Inclining to oval, light, thin, covered with a horny epidermis, spire produced into an acute pyramid; whorls slightly angulated in the centre, rounded beneath; aperture elliptical, slightly modified by the last whorl; inner lip planed; outer lip thin; operculum horny, subspiral. Found in brackish water; one species may be procured abundantly on the muddy shores of the Thames, in Kent. There are also species from Calcutta, China, Tahiti, and Australia. Without comparing the animals, it is difficult to distinguish this genus from some species of Littorina. Fig. 363. A. Grayana. ASTACOLUS. Montf. A genus of microscopic Foraminifera. CRISTELLARIA Crepidula, Lam.