270 PUOf. ALLMAN ON NEW GENEUA 



below, slightly narrowing upwards, orifice with two narrow teeth 

 projecting from the inner side of the margin ; hydrothecse of the 

 main stem and branches separated from one another by consider- 

 able intervals. 



Gonosome. Gonangia borne by the stem and pinnae, each spring- 

 ing from a point just below the base of a hydrotheea, nearly ses- 

 sile, ovoid, with truncated summit, strongly annulated in their 

 distal half or two thirds, orifice borne on the summit of a narrow 

 tube which springs from the centre of the truncated summit. 



Locality. !N"ew Zealand, Mr. Busk's collection. 



This is a fine species, with a handsome plumose aspect, con- 

 ferred on it by the pinnate disposition of its ultimate ramuli. 



Thuiarta dolichocarpa. Plate XIX. figs. 3, A, and 4 a. 



Tropliosome. Hydrocaulus attaining a height of about four 

 inches, and formed by an undivided main stem with closely set 

 pinnately disposed, simple, opposite ramuli. Hydrothecae alter- 

 nate, closely set on the ramuli, more distant on the main stem, 

 diverging upwards ; margin of orifice strongly toothed, with a 

 deep notch on each side, separating it from the hydrocaulus, the 

 notch surrounded by a thickened rim ; teeth three on each side 

 of the orifice, and one in front ; hydrothecse adnate to the pinnae 

 from their base to the bottom of tlie marginal notch ; pinnae with a 

 strongly marked mesial keel running down each side ; main stem 

 not keeled, with joints at irregular intervals, and its hydrothecae 

 more distant, and with the margin less distinctly dentate than 

 is the case with the hydrothecae of the pinnae. 



Gonosome. Gronangia springing by a small basal joint from the 

 pinnae, close to the base of a hydrotheea, very long, being about 

 twelve times the length of a li^'drotheca, rapidly widening upwards 

 for some distance from their origin, then becoming nearly cylin- 

 drical to within a short distance of the summit, and then continued 

 by a short, tubular prolongation, which, carries the terminal orifice. 



Locality. Northern Island, New Zealand, Di\ Andrew Sinclair, 

 Mr. Busk's collection. 



Thuiaria dolichocarpa is a striking form, conspicuous by its 

 pinnately disposed opposite ramuli, springing from a simple stem, 

 and giving to the entire Hydroid an elegantly plumose habit, as 

 well as by the strongly dentate margin of its hydrothecae, and its 

 greatly elongated gonangia. The strong keels running down, one 

 on one side and the other on the opposite side of the pinna, to 



