HYDROIDA. 119 



slightly overlap one another and are more oval in shape. Margin with two teeth. No 

 gonothecse present. 



There is such a small piece of this, that although the characters do not agree with 

 those of any known species of Thuiaria, still I do not feel justified in describing it as 

 a new form. 



Locality: Gulf of Manaar. 



Thuiaria palans, n. sp. Plate III., figs. 5, 5a. 



Trophosome. Stem of a bright brown colour, branched, with a joint just below the 

 origin of each branch. Branches alternate, long and straggling. Hydrothecse two or 

 three to an internode on the stem, four or five on the branches, adherent up to quite 

 near the top, when they become free and divergent ; margins reduplicated and with 

 two lateral teeth. 



There is only one broken piece of this form 2^ inches in height, but it seems so 

 distinct from all previously described species that I feel bound to describe it as new, 

 and I believe the above characters will determine it. 



Locality : Palk Bay, 7 fathoms. 



Desmocyphus palkensis, n. sp. Plate II., figs. 7 to 7 b. 



Trophosome. Hydrocaulus 2|- inches in height, with a dark brown stem, pinnately 

 branched ; the pinnae paler in colour, alternate, one to an internode, with a straight 

 and an oblique joint shortly above their point of origin. 



Hydrothecae alternate on the stem and separated from each other by its width 

 (Plate II., fig. 7), adnate for of their length, one in the axil of each pinna 

 and one on either side of the internode above ; on the pinnae they are opposite, a 

 pair to each internode (fig. 7a), adnate for f of their length in front, free and 

 divergent above, with two lateral teeth and an operculum. 



Gonosome. Gonothecse borne on short stems below the hydrothecae on the stem, 

 oval, strongly ringed, with a wide neck (fig. 7b). 



Locality : Palk Bay, 7 fathoms. 



These sj^ecimens are broken off above and below, but have the appearance of being 

 nearly complete. They resemble Desmocyphus longkheca, Allman (3), in some 

 respects, but the hydrothecae on the stem are never opposite and adnate to one 

 another and the specimens are I J inches taller. 



Synthecium orthogonia (Busk) (10). 



A few of the hydrothecae on these specimens are subalternate. 



Locality : The species is known from Port Jackson. Our Ceylon specimens were 

 found on the experimental oyster cages on the Cheval Paar, Gulf of Mannar. 



