anciennement décrite par Velley et dont le Muséum possède un fragment rapporté des Iles Sandwich par M. Gaudichaud, à laquelle on pourrait appliquer le nom spécifique de Velleyanum, pour rappeler celui du botaniste qui le premier l'a bien fait connaître; l'autre, signalé comme variété du C. umbilicata, par M. Agardh, conserverait le nom de M. tenuius. Ces changements me paraissent d'autant plus motivés que le caractère tiré de la fronde ombiliquée peut s'appliquer indistinctement à chacune des espèces, aujourd'hui connues, et qui sont : 1. Hydrodictyon umbilicatum, var. tenuius, Ag. Syst. Alg. 85; 2. Conferva umbilicata, Velley, Linn. Trans. v. 169. t. 7; 3. Anadyomene Calodictyon, Mont. Pl. Cell. Canar. 180." In the Ann. des Sciences Naturelles, série 2. xvii. 327, M. Decaisne quotes-1. M. Agardhianum; 2. M. Velleianum; 3. M. tenuius.

Endlicher, in his 'Mantissa Botanica, sistens Generum Plantarum Supplementum Tertium,' 1843, places the genus Microdictyon with the genera Hydrodictyon and Talarodictyon, in the family Hydrodictyea, but the fructification of Microdictyon is unknown, and there is no reason to believe that the cells produce perfect netted plants as in the freshwater genus.

Endlicher also refers to the genus Dictylema of Rafinesque, Somiologia, n. 54, as a synonym of the genus.

Professor Endlicher refers to three species of the genus :

1. M. Agardhianum, Dec. 64.-Hydrodictyon umbilicatum, var. tenuius, Agardh, Syst. 85. Mare Rubrum.

2. M. Velleyanum, Decaisne, 1. c.-Conferva umbilicata, Velley in Linn. Trans. v. 169. t. 7, ad insulas Sandwichenses.

3. M. Montagneanum.--Anadyomene Calodictyon, Montagne, Flora Can. Plant. Cell. 180. Mare Atlanticum.

It is to be observed here, that though the names of two are quoted as Decaisne's, he has changed two of them.

M. Decaisne, in his paper above quoted, believes there are three species, but he does not attempt to give any characters to distinguish them, except the localities where they are found; and Professor Harvey, though he found three species, gives a name only to one of them, which he regards as similar to those described by Montagne from the Canaries. Kützing, in his Species, in p. 512, gives specific characters for M. Agardhianum and M. Calodictyon, copied from Montagne, who gives it to distinguish from his Anadyomene. Unfortunately I am

Sereat oras w & Lave been promulgated from time to time last as to the supposed injurious effect of LL of Berterus to cum, a notion very prevalent amongst Intotenattia, & di berto somewhat laughed at by scientific men. If Ralons are cor firmed, it will be impossible to deny

hat the agriculturists have been in the right.

The Treaty of Bang, a Popular Dictionary of the Vegetable King-
dom, with which is incorporated a Glossary of Botanical Terms.
Edited by John Lindley, Ph.D., F.R.S., F.L.S., and Thomas Moore,
F.L.S., assisted by numerous contributors. In two parts. London:
Longmans.

This companion volume to Maunder's 'Treasuries' must be wel comed as a useful book of reference on popular matters relating to the vegetable kingdom, and supplies a long-felt desideratum. Its object is to give a familiar and concise account of every genus of plants, with special reference to those species, useful, ornamental, or curious, on which information is likely to be sought by the general public; and it is but just to acknowledge that this object has been fully attained. The work is arranged alphabetically, and illustrated by numerous woodcuts and twenty beautiful steel engravings. A glossary of botanical terms is also embodied, and some notion of the geography and physiognomy of plants may be gathered from the introduction, written by Dr. Seemann, and intended as a commentary of Mr. Adlard's truly exquisite steel-engravings. The plan of the work was ingssil sketched out by the late Dr. Lindley, who, in conjunction with Mr. Thomas Moore, became the editor. But he was not able to exercise his functions further than the letter C, and long ere the printing of the whole work was completed, he died, leaving the task

sheets through the press, verifying names and

innumerable gaps, to his able coadjuto

happy to be able to add that t

contributors, but most of

studies that we wonder how they could possibly manage to throw off so many valuable articles, and we suppose the editor had to write no end of polite notes requesting additional supplies of manuscript at their earliest possible convenience. All the articles, with the exception of the editorial ones, are signed, and they are contributed by the following botanists, viz. Professor Balfour, Rev. M. J. Berkeley, Mr. A. A. Black, Mr. W. B. Booth, Professor Buckman, Mr. W. Carruthers, Mr. B. Clarke, Professor Dickie, Mr. W. B. Hemsley, Mr. R. Heward, Rev. C. A. Johns, Dr. Masters, Dr. Moore, Mr. T. Moore, Dr. Seemann, the late Mr. Alexander Smith, Mr. J. T. Syme, Mr. R. Thompson, and Mr. W. Thompson.

Annotationes Critica in Cupuliferas nonnullas Javanicas.

Auctore

C. A. J. A. Oudemans. Amstelodami. 1865. 4to, pp. 29. Cum Tab. XII.

The Oaks of which Professor Oudemans here makes mention, were for the most collected by Junghuhn in Java, and the detailed comparison he has been he has been able to make of them with other specimens in the Royal Herbarium, in that of the University of Leyden, and in that of Professor Miquel, 1, have enabled him to correct the synonymy and give more accurate and copious details of some of these puzzling plants. Two new species are described, viz. Q. conocarpa and Lithocarpus scutigera. Twelve lithographed plates accompany the descriptions, to which is also added an analytical table of the Oaks of Java arranged chiefly according to the pecu

not able to examine either the species discovered by Botta in the Red Sea or the one found in the Canaries, as there are no specimens of them in the British Museum or my own collection, which only contains the species discovered in Natal by Dr. Krauss, and the three species collected by Professor Harvey in Australia and the Tongan Islands.

The four specimens in the British Museum appear to be very distinct species, but it is very difficult to distinguish them in words; this difficulty partly arises from the very imperfect state in which they are,a defect generally incidental to Chlorospermous Alge in a dried state, and especially to Algae of such a tender and fragile nature as the genus under consideration.

In the following schedule I commence with the three species named by Decaisne, of which I know nothing except what is contained in the works quoted.

*Frond umbilicate, affixed by the centre.

/ 1. M. Velleyanum; frond expanded, fan-shaped, fixed in the centre; filaments very minute, slender; cells longer than broad; the colour blackish when dry, sombre green when fresh.-C. umbilicata, Velley, Linn. Soc. v. 169. t. 7. (1799). Hydrodictyon umbilicatum, Agardh, Syst. 83. M. Velleyanum, Decaisne, Arch. du Mus. ii. 117 (1834); Ann. Soc. Nat. ser. 2, xvii. 327; Endlicher, Mantissa, ii. 1843. M. Agardhianum, Decaisne; Harvey, Alga Austral. Exsiccatæ, n. 568.

HAB. Australia: New South Wales, on the stem of a large fucus, Governor Hunter, Velley; Harvey, Phycologia Australica,' t. 50. Sandwich Islands, Gaudichaud; abundant in Port Jackson and Paramatta River, Harvey.

Decaisne established this species from Colonel Velley's figures and descriptions, and from a fragment that M. Gaudichaud brought from the Sandwich Islands, which is in the herbarium of the Jardin des Plantes at Paris.

2. M. Calodictyon; filaments moderately thick." Fronde solitaria, suborbiculari e viridi fusco nigrescente, cribrosa, margine dissecta lobataque; venis quinis, mediis erectis, binis inferioribus patentibus (vel deflexis) membrana nulla annexis. Discus mamillatus scutatus, excentricus, hinc Alga umbilicata. Frons solitaria, planiuscula, diametro uncialis, margine erosa et irregulariter dissecta, tenuissima, tota venis compositis, pellucidis, confervoideis, primariis quinis, quorum tres medianæ exsertæ, binæ venæ inferiores horizontali-patentes cum secundariis quam

plurimis inter seseque anastomosant, nec ut solenne est in congeneribus membrana ulla conjuncta sunt.-Montagne in l. c. A. Calodictyon, Montagne in Webb and Berthelot, Fl. Canar. iv. 180. t. 8. f. 1 (1850). M. Agardhianum, Decaisne, Arch. du Mus. ii. 115, 117, not Endl. M. Montagneanum, Endlicher, Mantissa, ii. 14. M. Calodictyon, Decaisne; Kützing, Sp. Alg. 512.

HAB. Atlantic Ocean, Canaries, Webb and Berthelot.

2. M. Montagnei; filaments moderately thick, the colour white or yellowish when dry.-" Microdictyon Montagnei," Harvey, Alga Insul. Amicorum Exsicc. n. 89.

HAB. Friendly Islands, Harvey, Herb. Brit. Mus.

The specimen of M. Montagnei, no. 89, from Professor Harvey's collection, of specimens of Australian Alge in the British Museum, is very distinct in the large size of the cells, in the distribution of the branches, and in the colour of the dried specimens, from the other Australian and the Natal specimens in the Museum.

3. M. Kraussii; filaments very slender, filiform; frond flat, divided into wedge-shaped lobes from a central disk, having several more or less imbricate lobes at the centre; colour blackish when dry; Calodictyon.-M. Velleyanum, "Decaisne;" Krauss, Pflanzen des Cap- und Natal-landes in Flora, 1846, 215, “in Batav. 210.”

HAB. S. Africa: Natal, Krauss, n. 273, Herb. Brit. Mus.

**Frond flat, foliaceous, imbricate at the base.

4. M. tenuius.-Hydrodictyon umbilicatum, var. tenuius, Agardh, Syst. Alg. 85. M. tenuius, Decaisne, Ann. Sc. Nat. 2 ser. xvii. 327. M. Agardhianum, Endlicher, Mantissa, 14, not Decaisne.

HAB. Red Sea, Djedda, Botta, Herb. Paris.

"The specimens from the Red Sea are smaller than that described by Velley, forming a kind of simple, foliaceous, flat expansion, at the centre of which grows a considerable number of lamellæ."-Decaisne, Arch. du Mus. ii. 116.

Genus 2. PHYLLODICTYON, n. g.

The frond oblong, free, lobed or confluent ?, arising from a slenderbranched articulated filament; the basal filament elongate, with opposite branches, each ending in a frond with a central rib, giving off close opposite branches at right angles to the main stem and each other.