Five hundred and sixth meeting. April 8, 1862.-MONTHLY MEETING. The PRESIDENT in the chair. The Corresponding Secretary read letters relative to the exchanges of the Academy. Also a letter from the Rev. James M. Peirce, of Cambridge, in acknowledgment of his election as a Fellow. Professor Rogers exhibited Plateau's experiments on thin viscid films and bubbles, with some original ones. Professor Lovering, in behalf of the majority of the Rumford Committee, presented the following Report. The Rumford Committee, having examined the subject of Hot-air Engines, and the recent improvements in their construction made in America, ask leave to report as follows: The Rumford Committee does not recommend that the Academy should award the Rumford Premium for the alleged recent improvements of Mr. Ericsson in the Hot-air Engine, nor for his engine as at present constructed. MORRILL WYMAN, JOSEPH LOVEring, JOSEPH WINLOCK. CAMBRIDGE, April 8, 1862. Professor Horsford presented the following Report from the minority of the Committee. The minority of the Rumford Committee report : That they dissent from the opinion of the majority, in that they believe the improvements in the caloric engine of Mr. Ericsson, which he brought out in 1858, are such as to entitle him to the Rumford Medal. They see in them evidences of high inventive talent, of patient thought and prolonged and persevering experimental research, in the practical solution, on a large scale, of the various problems underlying the hot-air engine; —especially in the compact arrangement of the supply and working pistons, the telescopic tube, the fire-pot, and the regenerator in a single cylinder, thereby economizing heat and space; in the device for protecting the lubricating material of the packing of the working piston, by exposing it at each stroke to the current of entering cold air; and in the system of cranks, rockshafts, levers, and their connecting-rods, by which the varied, complicated, but necessary motions of the supply and working pistons are regulated and connected with each other and the fly-wheel. The minority recommend that the Rumford Medal be awarded to Mr. Ericsson for his improvements in the management of heat, particularly as shown in his air engine of 1858. CAMBRIDGE, April 8, 1862. E. N. HORSFORD, The two Reports being accepted, the subject was discussed in detail by Professors Horsford, Lovering, Winlock, Peirce, and Treadwell. And, on motion of Professor Horsford, an adjourned meeting was voted to be held on the 22d instant, for the further consideration of the subject. The VICE-PRESIDENT in the chair. The Corresponding Secretary read a letter from Professor Trendelenburg, of Berlin, in acknowledgment of the notification of his election as a Foreign Honorary Member of the Academy. He presented, from the author, a paper entitled Plantæ Wrightiana e Cuba Orientali, a A. GRISEBACH: Pars II. Also the following communication from Professor Tucker man. Observations on North American and other Lichenes. By EDWARD TUCKERMAN, A. M. (Continued from Vol. IV. p. 407.) OMPHALARIA LEPTOPHYLLA, sp. nov.: thallo membranaceo-cartilagineo glabro atroviridi subtus subconcolore e centro in lobos undulatos apice latiori rotundatos repandos mox sinuato-lobatos diviso; apotheciis minutis submarginalibus innato-prominulis demum pallidis tuberculiformibus disco punctiformi impresso. Spora in thecis elongatoclavatis octonæ, ellipsoideæ vel demum oblongo-ellipsoideæ, incolores, simplices, protoplasmate in guttulas (1-2) secedente diam. 14-24-plo longiores. "On rocks in rivulets, overflowed after rains," in the island of Cuba, Mr. Wright. Thallus rather thin, but firm, smooth, blackishgreen or nearly black, (the largest specimens, perhaps, an inch in their longest diameter,) dividing at the centre into wavy lobes, with wider, rounded, repand tips, and becoming more or less sinuate-lobate, with often a plume-like aspect; or, less regularly, passing into narrower divisions. Gonimous granules of scarcely middling size, subsolitary, the filamentous elements amongst which they are interspersed being exceedingly delicate. Apothecia minute, superficial, becoming at length a little paler than the fronds, disposed in necklace-like chains, or sometimes in heaps, at or near the margin of the lobes, tuberculiform, and the disk punctiform-impressed, or more rarely at length flattened and sublecanorine. Spores in eights, in long-club-shaped sporesacks, colorless, ellipsoid, or at length oblong-ellipsoid, simple; the protoplasm dissolving more or less into roundish drops; once and a half to twice and a half longer than wide. Paraphyses distinct, filiform. The subsolitary gonimous granules and more delicate filamentous elements separate this plant, as does also the thinner and more divided thallus, from Omphalaria Girardi, DR. & M., the type of the genus, both with Montagne and Nylander; but I know of no lichen with which I should sooner compare it. O. Girardi is, however, only known to me in infertile specimens (determined by Dr. Nylander, Syn., p. 99) which were detected by T. M. Peters, Esq., in Alabama. Collema laciniatum, Nyl. 1. c. p. 116, which accompanies the Alabama lichen, grows intertangled with the present in Cuba. The apothecia of the present are at length rather prominent, for the most part peritheciiform; but they assume at length, in the oldest condition, a more regular and sublecanorine aspect. OMPHALARIA LINGULATA, sp. nov.: thallo subcartilagineo viridifuscescente (fusco-nigrescente) e basi umbilicato-affixo in lobos spathulato-oblongos subsimplices plano-convexos subtus obscuriores diviso; apotheciis sparsis minutis crinatis pallidis disco impresso margine integro subprominulo demum cincto. Sporæ octonæ in thecis clavatis, incolores, oblongo-ellipsoidea, simplices, protoplasmate granulosa vel guttulosa diam. 2-3-plo longiores. On rocks, "Farallones la Cavalina (M. Revel, near Sagra)," in the island of Cuba, Mr. Wright. Thallus rather thinnish, but cartilagineous, fragile, of a brownish-green becoming at length blackish-brown color above, and mostly, or at length, darker below, dividing at the umbilicate base into oblong, spatulate, or tongue-shaped lobes, which are commonly subsimple, but occur also irregularly, and similarly but sparingly lobulate; slightly convex above, and margined for the most part, but scarcely canaliculate, below. Gonimous granules glomerulate, interspersed among anastomosing filamentous elements. Apothecia minute, scattered, innate, pale; the small impressed disk bordered by an at length slightly prominent and entire thalline margin. Spores in eights, in clubshaped spore-sacks, colorless, oblong-ellipsoid, simple; the protoplasm becoming guttulose or granulose; twice to thrice longer than wide. The apothecia resemble the smaller ones of Collema pustulatum, Ach. (nor does it appear otherwise than likely that the commonly verrucarioid apothecia of the last species express anything else than the lecanorine type, in a state the perfect development of which is for the most part precluded), and are sprinkled pretty thick over the thallus, much as in that species; but the gonidia are not concatenate, but glomerulate in the present, which is also affixed at a single point at the base, as in Omphalaria. The dimensions of the lichen vary from half to three quarters of an inch in the longest diameter, but single lobes occur among the specimens, which are much broken, of the same length. COLLEMA COCCOPHORUM, sp. nov.: thallo minuto orbiculari crasso nigro lobis periphericis expansis crenato-incisis centralibus adscendentibus granulato-lobulatis; apotheciis majusculis subplanis disco rufofusco margine thallino tenui cincto. Sporæ octonæ, incolores, ellipsoidea 1. ovoideo-ellipsoidea, diblastæ 1-2-plo diametro longiores. On sandy earth in the valley of the Rio Grande, Texas, Mr. Wright. Small, roundish fronds, the largest of which a little exceed an inch through, of very small, thickish, black lobes, which are radiose-expanded, and crenate-cut, at the circumference, with mostly raised, at length granulate margins; and becoming towards the centre densely lobulate-granulate (with the aspect of a crust of black granules). Gonimous granules concatenate, amongst anastomosing filaments. Apothecia largish (often a line and a half through), flattish or plano-convex, the dark-reddish-brown disk enclosed by a thin, at length uneven and even granulate thalline margin. Spores colorless, ellipsoid and ovoid-ellipsoid, simple, or at length diblastish, once and a half to 49 VOL. V. twice and a half longer than wide. This little species, of which abundant specimens were collected by Mr. Wright, is comparable with small states of C. cheileum (as Moug. & Nestl., n. 1056); but is more minute, with a different habit of thallus, and spores which appear never to be more than diblastish. The latter feature, if constant, separates it also from other allied species. COLLEMA CALLIBOTRYS, sp. nov.: thallo mediocri suborbiculari membranaceo-cartilagineo rigidulo glauco-virescente lobis radiose expansis mox angustatis costatis lobulis adscendentibus capituliformi-dilatatis vel botryoso-difformibus apotheciis confertissimis mox coopertis ; apotheciis minutis disco concavo-plano rubello excipulo thallino integerrimo fuscescenti-pallido recepto. Sporæ octonæ in thecis subcylindraceis, incolores, primo subquadratæ, sporoblastis 4 cruciatim dispositis dein longiores, ellipsoidea sporoblastis pluribus muriformi-dispositis vel oblongæ, diam. 2-3-plo longiores. On trunks of Carya, Santee Canal, South Carolina, Mr. Ravenel. Thallus exceeding an inch in diameter, of rather separate, radiose-expanded, somewhat membranaceous but rigid, glaucescent-green lobes, which become narrowed and laciniiform, and more or less ribbed, as well as sparingly divided, and pass into short, erectish, dilated branches or clusters, covered at length and concealed by the crowded apothecia. Gonimous granules concatenate, amongst distinct, much branched, anastomosing, filamentous elements. Apothecia in crowded clusters, very minute, depressed-globose; the concave, or at length flat, dark-reddish disk received in an entire, palebrownish, thalline exciple. Spore-sacks subcylindraceous, octosporous. Spores at first somewhat square; the four sporoblasts arranged crosswise, but becoming longer and with more and smaller sporoblasts (more or less murally-polyblastish), and at length ellipsoid or oblong-ellipsoid, and from twice to thrice longer than wide; the longer ones sometimes pretty regularly tetrablastish, but the sporoblasts more often, or some of them, divided longitudinally. The affinity of this plant is not doubtful. C. verruciforme, Nyl. (C. furvum, var. verruciforme, Ach.) is its European analogue, differing (as in Schær. Lich. Helv. n. 416, and in the excellent description of Mr. Th. Fries, Lich. Arct. p. 279) in its minuteness, its ascending, densely complicate lobules, and shorter spores, which do not appear to attain to the same development; and an Asiatic also exists, in C. coccophyllum, Nyl. Syn. p. 112, from the Nilgherry Mountains in India, presenting spores agreeing exactly (Nyl. 1. c., t. 4, f. 20) with the first-described state of the spores of the |