BOUGAINVILLEA NIGRITELLA. 63 



these lobes will probably hereafter be found young Bougainville^ produced by gemmation, 

 in the manner described as occurring in the following genus. The appearance of eight 

 peduncular lobes represented in Mertens's dra.mngof Hippocrene Bougainvillii, {BougainvilUa 

 Macloviana, Lesson,) is probably due to this cause ; the four intermediate ones being gemmae, 

 symmetrically developed, in this respect differing essentially from the unsymmetrical develop- 

 ment so strangely exhibited by Zinnia. Those who have opportunities of hereafter examining 

 our British Bougainvillea, should let no specimen pass until the mode of reproduction, be 

 discovered. When found, I feel quite confident it will prove to be of the order now indicated. 

 1, e, represents one of the ramified lips, with its gland-like extremities;: \,f, is one of the 

 four fasciculi of tentacles and tentacular bulbs. 



2. Bougainvillea nigritella, Forbes. 



A second British species of Bougainvillea — one, too, remarkably distinct from the first — 

 was discovered by Mr. M'Andrew and myself in the Sound of Brassay, Zetland, during the 

 autumn of 1845. 



It is very minute, not more than half the-size of its congener. The umbrella is globose, 

 smooth, transparent, and colourless. It is contracted at its opening, which is quadrangular, 

 each angle bearing a compact, oblong, or almost kidney-shaped mass of tentacular bulbs, 

 apparently four in number, closely united together, so that, but for indications of lobation at 

 the lower part of the pad, the number of these bodies would be indeterminable. The upper 

 half of the pad is yellow, the lower jet-black, the two colours separated in a very defined 

 manner. On one side of each pad arises a very short, thick, yellow tentacle, and one only. 

 The sub-umbrella, which occupies about two thirds of the body, is divided into four parts, the 

 simple gastric vessels, each of which unites with the marginal vessels opposite the centre of 

 one of the ocellated pads. The peduncle is short, and divided above into four rather thick 

 oblong lobes, of a yellow colour ; below it is produced into a short, campanulate, yellow 

 stomach, terminating in four tentacle-shaped, white lips. Each lip becomes suddenly filiform, 

 proceeds for some distance simple, and then divides into two, again bifurcating before 

 it terminates. The end of each division is a conical gland-like body, white speckled with 



black. 



Plate XII, fig. 2, a, represents Bougainvillea nigritella of the natural size ; 2, h, mag- 

 nified in profile ; 2, c, seen from one side ; 2, d, the peduncle and hps ; 2, e, one of the lips 

 with its sucker-like terminations ; 2, /, one of the masses of tentacle-glands, and the single 

 tentacle. 



