492S^ Mr. J. Miers on some genera of the Icaciuacese. 



cells, placed in the four salient angles of this connective, are 

 formed by the continuation of the same cuticle, which here ceases 

 to be adherent to the fleshy centre ; the epidermis forms the 

 anterior or external casing of the crustaceous cells, while the 

 inner tegument constitutes the posterior lining of the cavity, 

 which is at the same time free from the connective, although in 

 contiguity with it, and which seems to form the receptacle for 

 the attachment and assimilation of the pollen-grains : the pollen- 

 cells, therefore, in reality appear to consist merely of a linear 

 separation between the two membranes at the angles of the 

 anther, and in all transverse sections of the same placed under 

 the microscope, no sutural break in the continuity of the epider- 

 mis is discernible on either margin, where by its reduplication 

 it becomes attached to the fleshy connective, nor is there any 

 indication of a line of rupture or dehiscence. I confess therefore 

 my inability to perceive, in any anther I have examined, the 

 smallest appearance of bursting of the pollen-cells. M. Tulasne, 

 on the contrary, states that they open longitudinally, by a fissure 

 along the face of the connective ; but whether sinistrorsely, or 

 dextrorsely, or alternately so, he does not explain. In the 

 summit of the anther, the same continuous crustaceous cuticle 

 is extended, and drawn up into a short cylinder, or obtuse apical 

 point, without any intervening connective, which apical point is 

 again reflected downward along the upper portion of the anterior 

 face of the anther, vanishing between the summits of the two 

 anterior pollen-cells ; the nature or function of this process is 

 not apparent. In the structure of its pistillum, Poraqueiha re- 

 sembles that of Mappia. Of its fruit nothing is recorded, more 

 than that in its unripe state it is spherical, smooth, and mucro- 

 nated. Although M. Tulasne has given a very elaborate descrip- 

 tion of this genus, it appears to me the following is a more 

 correct expression of its character. 



PoRAQUEiBA, Aubl. — Floves perfecti. Calyx imo brevissime 

 cupulatus et carnosus, limbo 5-partitus, laciniis ovatis vel 

 subacutis, ciliatis, sestivatione quincuncialiter imbricatis, per- 

 sistens. Petala 5, sequalia, oblonga, carnosa, marginibus 

 summo apiceque propendenti inflexis, intus carina profunda 

 superne longitrorsim ex altera mediana trans versali decurrente 

 ..jet in laminam latam concavam usque ad imum continuam 

 incruciatim disposita, m.odo ut in locellos quinque sic divisa 

 sunt, nempe, 2 superiora et 3 inferiora (vel carina suprema 

 defectu solummodo in imo 3-locellata), locellis profundis 

 glabris, carina suprema scabrido-papillosa, in compitum fasci- 

 culo pilorum donata, pilis rigidis albidis erecto-patentibus, 

 sestivatione valvata^ sub anthesi reflexa. Stamina 5, cum petalis 



