LITUOLÆ. Lam. The third family of Polythalamous Cephalopoda, Lam. the shells of which are described as partially spiral, the last whorl continuing in a straight line. The transverse septa which divide the chambers, are in general pierced by a siphon which breaks itself off before it reaches the succeeding septum. This family contains the genera of microscopic Foraminifera Lituola and Spirolina. The genus Spirula, also placed in this family, does not by any means agree with Lamarck's definitions "the last whorl continuing in a straight line." LITUUS. Humph. CYCLOSTOMA? Lam. LIVID. (From _lividus_.) Of a pale, dull, blue colour. The adjective is sometimes used as a specific name. _Ex._ Conus _lividus_, Sanguinolaria _livida_. LOBARIA. Schum. SANGUINOLARIA rosea, Lam. (fig. 98) and other similar species. LOBATE or LOBED. Divided into parts. LOBATULA. Fleming. A genus composed of two very minute species of chambered shells. Serpula lobata and S. concamerata, Mont. Test. Brit. 515. LOMASTOMA. Rafinesque. An imperfectly defined genus, probably belonging to the Limnacea. LONGITUDINAL. Lengthwise. Longitudinal striæ, ribs, &c. are those which radiate from the apex and follow the spiral direction of the whorls, in spiral shells; and from the umbo to the ventral margin in bivalves. The term "decourantes" is employed by French conchologists. The bands in Achatina, fig. 286, are longitudinal or spiral. LORIPEDES. Poli. A genus composed of species of LUCINA, Auct. in which the lunules are not prominent. LOTORIUM. Montf. A genus composed of species of TRITON, Auct. in which the aperture is effuse. T. Lotorium, fig. 400. LOTTIA. Gray. PATELLOIDA, Quoy and Gaimard. LUCERNA. Humph. A generic name applied to some species of Helix included in De Ferussac's sub-genus Helicogena. LUCERNELLA. Sw. A genus of "Lucerninæ," Sw. thus described: "Teeth on both sides of the aperture; surface regularly and distinctly striated. Circumference convex." LUCIDULA. Sw. A sub-genus of Lucerna, Humph. thus described: "Aperture transverse, both lips much thickened and united; the outer with marginal obsolete teeth at the base; umbilicus closed. Barbadensis, _Lam._ No. 49. p. 78. Fêr. Moll. pl. 47, 2, 3, 4."