100 Prof. M'Intosh's Notes from the 



Circe (probably G, horealis), Sarsia, Turn's^ Oceania, and 

 others — not at the surface, but very often at a depth of 3 or 

 4 fathoms. Occasionally, indeed, certain conditions of the 

 wind and tide strew the l3each in May with masses of Thau- 

 mantias and other forms ; but they may exist in great pro- 

 fusion, while only a few stragglers are caught by the ordinary 

 tow-net. 



The active planulse from a vessel containing abundance of 

 Sarsim amongst Thaumantias and other forms noted were 

 placed under a trickle of water on the 30th July, 1886. 

 Some time afterwards many minute pale hydroids were noticed 

 on the bottom of the vessel ; but it was not till the first week 

 in March 1887 that a delicate hydroid was observed stretching- 

 over the bottom of the vessels. This period would nearly 

 correspond with that at which Dujardin originally found the 

 Syncoryne proceeding from the pelagic Sthenyo *. Further 

 examination showed that these growths were formed by a 

 single species, viz. the Syncoryne decipiens, Dujardin, the 

 faithful pencil of the late Mr. Alder leaving little to be 

 desired in the figure in Mr. Hincks's work. It is clear there- 

 fore that either the planula of this species alone had been 

 selected for the experiment, which is unlikely, or that it 

 survived frequent vicissitudes which caused the others to 

 succumb. 



As Mr. Hincks had no opportunity of examining living 

 specimens, it may be noted that the minute and slender stem 

 (hydrorhiza) creeps over the surface of the glass often in a 

 somewhat radiate manner, sending off here and there free 

 erect branches, which bear the characteristic polypites at the 

 tip. These have for the most part the general aspect of 

 Mr. Alder's figure f ; but the slender transparent tentacles 

 are much longer in vigorous adults, and thus contrast with 

 the large globular or button-like tip with its prominent 

 thread-cells. The elongated oral region of the polypite is 

 pronounced, and the dilated region behind it is tinged of a 

 pale brownish hue. Small rounded bodies, of a pale brownish- 

 red colour, situated in most just behind the tentacles, though 

 in others they occur amongst the tentacles, indicate the gono- 

 pliores. 



The polypary shows more evident crenulations (annulations) 

 .than represented in the figure, and towards the beginning of 

 July this had undergone various changes in the colonies. 

 Many of the chitinous sheaths were empty, while here and 

 there, out of the wall of the effete tube, sprouted a slender band 



* Ann. des Sc. Nat. 3'= ser. iv. p. 277 (1845). 

 t Ilincks, Brit. Hydr. Zooph. ii. pi. x. f]g. 2. 



