AVlien arrived ut maturity — i.r.. the breaking up of the 

 plant — the new germ phmts become detached at an oval joint 

 immediately below the cup, and the latter l)eing the portion of 

 the greatest dennity retains the floating Avaif in an upright 

 position, and soon proves its ultimate use by acting as a 

 grapiylinf/ apjmratus, catching in tlie tangles of small alga^, &c. ; 

 preventing the removal of the young plants to places unsuit- 

 able for them, anchors them firmly in the soft mud, and thus 

 ensures their prosperity and continuation, whilst the old ones 

 are being destroyed by storms and currents. 



Having examined numerous specimens, I can speak with 

 confidence in respect of the latter stages of growth ; but being 

 too late in the field for this season 1 have neither seen flowers 

 of either sex, nor found the cup-plants in connection with the 

 parent. The remarks, as to thcNse, ai*e therefore only conjec- 

 tural. Observations ought to be made at the proper time by 

 dredging for the plants, the weather being too cold then for any 

 other mode. Perhaps the above may induce members with the 

 means at command to fill up the gaps in the life-history of 

 Cijmodocea as indicated, and thus set the (luestion at rest. 



ExPLANATtOX OF PlATE I. 



Fig. 1. Mature germ-plant, uat. size. A., horny calyx-cup, or 



bracts. 

 Fig. 2. Side view of A. a. Base of ovary (below oval depres- 

 (enlarged) sion joined to the stalk), to which 



are fixed four rayed wings in 

 adjoining pairs. 

 Ik The two inner spiny wings, opp. to 

 interstices of the outer ones, alter- 

 nating with two small projections. 

 c. Core, from which the young stem 

 arises. 

 Fig. 3. A'iew of A. from above, a. Large pair, with 14-15 rays, 

 (much enlarged) joined at base. 



h. inner spines, always five, 



not joined. 

 c. Small outer pair, with nine 

 rays, joined at base. 

 Fig. 1. Showing spiral roots proceeding from between the 

 wings, a. Koots. 



b. J Fair-like fibres attached, generally from 

 the exterior of the horny ciq). ^fat. size» 

 Fig. 5. Mature leaf, to show its peculiar structure (enlarged). 

 a. Clasping stalk ; inner and upper side. 

 1). Hinge or joint of leaf. 

 c. Projecting doid)le part and leaf. 



