This most charming _Odontoglossum_ was discovered in the year 1850 by M. Schlim at that time engaged in exploring the higher regions of New Granada in the service of M. Linden to whose well-known horticultural establishment at Brussels he had the honour of introducing it. The species was seen in flower for the first time in the year 1856 when it appeared at some Horticultural Exhibitions both on the Continent and in London and, as may readily be conceived, attracted universal admiration. Since that time its lovely blossoms have been rarely produced, owing no doubt to its cultivation having been imperfectly understood. It has however, I believe, bloomed occasionally in the collection of the Lord Chancellor of Ireland, and more recently in that of E. McMorland, Esq., of Haverstock Hill, with whom it thrives amazingly, and to whose kindness I am indebted for the opportunity of figuring it. In its native country it is found in a mild climate growing on the ground, or upon rocks in moist and shady situations, and by simply imitating these conditions Mr. McMorland cultivates it with the most perfect success. His plants are kept in pots, with living moss on the surface, and their base resting in pans of water the evaporation from which cannot fail to be highly beneficial. The temperature of the house in which they are grown is that of an ordinary greenhouse, but the air is always humid, and water is freely given because, in consequence of the _open potting_, it can pass as freely away. The plants seem to grow and flower almost all the year round, though their proper and principal flowering-season is in May and June. _O. phalænopsis_ is entirely distinct from any species of the genus yet in cultivation, but it is allied to a still finer plant detected by Warszewicz in Costa Rica, and called in honour of its discoverer _O. Warszewiczii_ by Professor Reichenbach. DISSECTIONS.--1. Lip. seen sideways; and 2. Front view of lip: _both magnified_. Plate IV [Illustration: Odontoglossum Insleayii.] PLATE IV. ODONTOGLOSSUM INSLEAYI, _Lindl_. INSLEAY'S ODONTOGLOSSUM. O. (EUODONTOGLOSSUM, _Lindl_.) pseudobulbis ovatis compressis diphyllis, foliis coriaceis oblongo-ensiformibus subundulatis apice recurvis racemo 5-10-floro erecto rigido brevioribus, sepalis petalisque oblongis subæqualibus undulatis infimis connatis, labello angusto obovato retuso basi auriculato, disci cristâ apice bilobâ dilatatâ utrinque in medio dente refracto auctâ, columnæ alis incurvis cirrhatis. (_Lindl. Fol. Orch._) ONCIDIUM INSLEAYI, _Barker in Bot. Reg._ 1840, _Misc._ 21; _Bateman, Orchid. Mex. et Guat. t. 21_; _Van Houtte, Flore des Serres,_ 1848, _t._ 62. Habitat in MEXICO, _Barker_; OAXACA, _Loddiges_; 5-6000 _ft._ DESCRIPTION.