IIVDROIDA. 113 



with a knee-like bend and then runs up almost parallel with the first ; another is 

 given oft* from this one again on the opposite side from the first, and so on alternately, 

 sometimes for nine times in succession, with no other form of branching. A more 

 complicated form of growth is seen when two branches are given off almost opposite 

 each other, or when the branches divide again. 



The sides of the hydrotheca are so compressible that the form of the teeth, in these 

 preserved specimens, cannot be seen satisfactorily. They are folded over as in Bale's 

 figure of Oampanularia bispinosa (12), and so are probably arranged in pairs as in 

 that species. 



Obelia hyalina, Clarke (13). 



A few fragments, probably of this form, previously found north of Goblos Island, 

 were found growing on oyster cages hung from the ship, between February 15 and 

 March 10, on the north-east of the Cheval Paar. 



Obelia australis, von Lendenfeld (17). 

 A few fragments of this form, previously found in New Zealand, were growing on 

 oyster cages hung from the ship, between February 15 and March 10, on the north- 

 east of the Cheval Paar. 



Obelia andersoni, Hincks (14). 



These specimens have rather more rings on the pedicels of the hydrothecae and 

 teeth on the hydrotheca margin than HlNCKS gives. He does not mention the height 

 of the colonies, nor whether they are branched. Our specimens are 5- of an inch in 

 height, and they branch occasionally, in which case there is always a hydrotheca in 

 bhe axil. The shape of the hydrothecae, which Hincks lays most stress on in his 

 diagnosis of the species, corresponds with these specimens. The line represented in 

 Hincks' figures running round the hydrotheca, near the base, is only to indicate the 

 beginning of the cylindrical portion, I believe ; it is not visible in our specimens. 

 This is a most delicately beautiful little species. 



Locality : Previously known from the Mergui Archipelago, it now occurs growing 

 on oyster cages hung over from the ship, between February 15 and March 10, on the 

 north-east Cheval Paar. 



Oampanularia juncea, Allman (1). Plate I., figs. 1 to Ib. 

 The specimens of this form in the present collection agree with Allman's description 

 for the most part, but our colonies reach a height of 18 inches instead of only 12, 

 while gonothecae are present, and in some cases an operculum on the hydrotheca 

 both structures previously unknown. Moreover, our colonies do not show the 

 division of the stem into internodes which Allman describes and figures. Still, this 

 is such a striking form that there can be no doubt about the identification. 



There are two kinds of gonothecse borne on separate colonies, which are thus of 



Q 



