Mr. J. Miers on Ephedra. 133 



was found by Mr. Cuming in groups, the specimens being in 

 many instances piled in layers one over the other, on a sandy 

 bottom, at a depth ranging from 5 to 9 fathoms. At Ancon 

 they were found attached to dead shells, and also clinging to 

 the wreck of a Spanish vessel of about 300 tons, that went down 

 in the bay about ten years before. The sunken timbers (for the 

 sheathing was gone to decay) were covered with these shells, 

 much in the same way that beams on land are sometimes in- 

 fested with parasitic Fungi. At Iquiqui they were taken ad- 

 hering to a living Mytilus. 



Figures of the type-specimens and groups of Crania and Or- 

 biciila will appear in the forthcoming thirteenth volume of the 

 *■ Conchologia Iconica/ to be published in the course of a few 

 days. 



XVI.— On Ephedra. 

 By John Miers, F.R.S., F.L.S. &c. 



[Continued from vol. ix. p. 437-1 



It has been the opinion of many botanists that the existence of 

 annularly dotted vessels in the wood of the Gnetaccce affords 

 evidence of their close affinity with the Coniferce; but even if this 

 had been true, it would have claimed, on its own merit, a very 

 secondary importance, since we find such vessels also in the 

 Winter ace.ee> Canellacece, Schizandracece, &c. Dr. Lindley says of 

 Gnetum that its wood " is composed of woody fibres and of annular 

 and reticulated vessels lying scattered sparingly among tubes of 

 woody fibre"*. He says also that its w r ood is zoneless. These 

 circumstances led that eminent botanist to conclude that the 

 Gnetacece arc very distinct from the Coniferce, forming a link 

 between Taxinece and Piperacece : this, at least, was his opinion 

 in 1834, although other considerations induced him afterwards 

 to modify his view of the place of this small family in the sys- 

 tem. I have noticed, however, that the wood of Ephedra is 

 regularly zoned, as in other exogenous plants; for a trans- 

 verse section of a branch of Ephedra Andina which I possess 

 shows five distinct concentric rings, the intervals between the 

 medullary rays exhibiting numerous longitudinal hollow air- 

 cells. The branches of Gnetum, on becoming dry, separate 

 readily at the nodes by distinct articulations ; but such separa- 

 tion rarely takes place in Ephedra. On the other hand, a lon- 

 gitudinal section of a new branch of the latter genus shows that 

 the central pith of one internode is not continuous with the pith 

 of the next internode, nor with that of their accessory branchlets; 

 * Bot. Reg. vol. . pi. 1086. 



