"endeavour" scientific results. 174 



the many other tubes constituting the fascicle. The cui've which 

 they make in emerging from the branch is continued down into 

 the latter, and constitutes the flexure ; below this they curve in 

 the opposite direction, accommodating themselves to the outward 

 flexure of the next branch let below. 



Examining the top portion of an unbroken branch we find it 

 to consist of the two branchlets last produced, each composed of 

 two outward-curved tubes, one of which has more or less distinct 

 internodes, while the other is unjointed. The latter does not 

 accompany the first beyond the point at which it becomes 

 ultimately united with other tubes to form the polysiphonic 

 branch. Accordingly below the second branchlet the stem con- 

 sists of four tubes, two of which afterwards become entirely 

 immersed in the fascicle, while two are continued outwards as 

 monosiphonic branchlets. I have also found the third branchlet 

 accompanied by its supplementary tube, and the stem below it 

 therefore consisting of six tubes, but .1 have not been able to 

 follow the structure further. The component tubes of the stem 

 are not easily teased apart without breaking the thinner ones, 

 even after boiling in liquor potassae; besides this treatment 

 shrivels and distorts them badly. I was able however to ascer- 

 tain that branching occurs among them. Some bear rows of 

 sarcothecas on the front, others are without them. 



The two oblique joints near the base of the branchlet include 

 between them a short internode bearing a small hydrotheca or 

 sometimes a hydrocladium, as pointed out by Ritchie. Below 

 this, where they curve into the stem, they may be divided into 

 several short internodes, or the nodes may be wanting here but 

 yet distinct lower down, where the tubes form part of the fascicle. 

 The double row of sarcotheca? is also continued for some distance 

 down into the stem. Successive branchlets on the same side 

 may be, in different specimens, from three to six millimetres 

 apart. 



The anterior sarcothecse ai'e very thick at the base and quite 

 rigid, and those above the hydrotheca?, though much narrower 

 at the point of origin, are pretty firmly attached. The laterals 

 however are freely moveable. Ritchie says that the two above 

 the hydrotheca are often replaced by a single one. 



The gonangia, like the rest of the polypidom, are of firm 

 robust texture. It is an unusual feature that they are entirely 

 without any thickening of the margin, which is quite thin and 

 even, and neither everted nor contracted, while the operculum 

 instead of being, as usual, on the summit, is wholly within the 

 capsule, and some distance below the margin. The ridge which 

 is situated inside the front is evidently a support on which the 



