74 MR JAMES RITCHIE: SUPPLEMENTARY REPORT ON 



Ca'm2^anulina chilensis, Hartlaub, L905. 



Three minute colonies epizoic on Halecium heanii belong to this species. The 

 ringing and branching of the stems and the shape of the hydrothecse agree with the 

 descriptions and figures of Hartlaub and of Jaderholm (1905), but although the former 

 says of the hydrothecse that they are " viel weniger conisch als die von C. repens, 

 Wright" [ ! Allman, 1864], I cannot distinguish between the hydrothecse of the South 

 American and British species. C. chilensis is, however, more frequently branched than 

 C. repens, but I doubt whether this and the other rather indefinite characters cited by 

 Hartlaub are constant and of specific value. Scarcity of material of both the South 

 American and British forms, however, prevents a comparison sufficiently extensive to 

 warrant me in setting them down as belonging to the same species. 



Measurements : — 





G. chilensis. 



C. repens.* 



Stem, diameter 



0-06 mm. 



0-08 mm. 



Hydrotheca, length . 



0-20-0-21 mm. 



0-18-0-28 mm. 



,, diameter at mouth 



0-09 mm. 



0-10 mm. 



Locality. — Growing upon Halecium heanii from Station 346, Burdwood Bank. 

 Lat. 54° 25' S., long. 57° 32' W. Depth, 56 fathoms. 1st December 1903. 



Jaderholm has already recorded C. chilensis from Burdwood Bank, where it was 

 growing on the carapace of a crab at 137-150 metres. Billard (1906,^'* p. 12), found 

 the species in collections from Flanders Bay and Booth- Wandel Island. Hartlaub's 

 specimens were obtained at Calbuco on Tubularia and Eudendrium. 



Thyroscyphus tridentatus (Bale, 1893). 



A few colonies have been found at a single locality. Simple, unbranched stems, 

 1 mm. in height, arise from a creeping hydrorhiza at intervals of some 2 or 3 mm. To 

 the unaided eye the colonies have an erect, rigid appearance, and are seen to bear pro- 

 minent hydrothese placed alternately on the stem. Under the microscope the stem 

 resolves itself into a series of distinct internodes which vary considerably in size, a much 

 shorter being occasionally wedged in between two longer individuals. That the nodes 

 in our specimen are apparently more distinct than those in the examples recorded by 

 Professor Hartlaub (1901, p. 369) from French Pass, to the north of the South Island of 

 New Zealand, is of little importance, as the boundary mark between internodes is liable 

 to considerable variation. The locality of the node is, moreover, rendered more evident 

 in the Scotia specimens, because the proximal end of each internode is generally 

 marked by a rude annulation. The hydrothecse are arranged alternately, and the 

 whole series lies in one plane. 



A hydrotheca rests upon a short process at the distal end of each internode. The 

 hydrotheca is separated by a distinct boundary line from the internodal process, and 

 occasionally one, two, or even three short joints intervene between them. The distal 



* Specimens from Plymouth in my collection. 



