168 Mr. J. Miers on the Affinities of the Olacaccse. 



strophiole, like that seen in the ovules of the Celastracea ; but in 

 ordinary cases the ovarium is unilocular, only by the suppres- 

 sion of one of the cells, and the confluence of the dissepiment 

 with the pericarpial covering, for it is then always somewhat 

 gibbous, and its wall much thicker on the side of the abortive 

 cell, towards which the style is then constantly somewhat lateral : 

 this fact serves to bring the genus completely within the pale of 

 the AquifoliacecB, as it is evident that its ovules are really 

 suspended from the normal dissepiment, not parietally attached 

 to the wall of an originally solitary carpel. It will also serve to 

 guide us to the true position in the system of Leretia, Pogope- 

 talum, and the rest of the somewhat extensive group of the Ica- 

 cinecE, which I shall be able to prove to be quite distinct, in 

 many leading and essential characters, from the Olacacecp.. Rhap- 

 tostylum, an anomalous genus of the Aquifoliacea, accords with 

 Heisteria in many remarkable points ; they agree in habit and 

 inflorescence, both having flowers in aggregated axillary clusters, 

 growing out of imbricated buds ; they have also a small 5 -toothed 

 calyx, a corolla of five petals partly cohering at base, but easily 

 separable, with a valvate aestivation, ten stamens, five of which 

 are opposite, and five alternate with the petals, and partly ad- 

 hering to them, a trilocular depressed and somewhat stipitate 

 ovarium, with a single ovule suspended in each cell, a short 

 erect style, and a clavate stigma : this close approximation of 

 characters is very apparent, but the subsequent development of 

 the calyx is not recorded in Rhaptostylum, nor is the nature of 

 its fruit known. The genus Ptychopetalum of Bentham also 

 agrees with Rhaptostylum in its principal floral characters, but 

 differs in its unilocular ovule with two suspended ovules, a nearly 

 constant feature of the Icacinece. From the description of 

 Kunth, the three cells of the ovarium are symmetrical, and not 

 lateral, as in Pogopetulum ; and as the fact of the evanescence of 

 the dissepiments at their summit probably escaped the observa- 

 tion of that botanist, we may safely conclude that Rhaptostylum 

 will be found to belong to Olacacece rather than to the tribe of 

 the Icacinem, or to the family of the Aquifoliacem. lodina again, 

 which has always been referred to the last-mentioned family, 

 really belongs, as I shall be able to show, to the Olacacece : this 

 curious genus presents a minute cupshaped bractiform calyx, 

 with an entirely free campanular fleshy corolla, half cleft into five 

 acute lobes, with a valvate aestivation : a large fleshy cup-shaped 

 disk, fixed on a distinct stipitate support within the corolla, sur- 

 rounds the ovarium, and upon its margin the stamens are in- 

 serted ; five of these are fertile, and placed opposite to the lobes 

 of the corolla, the others are alternate, squamiform and petaloid, 

 having been hitherto described as petals, but from their position 



