144 PKOF. ALLMAN ON NEW HTBEOIDA. EEOM 



broken from the distal end of a colony, and no evidence of the 

 entire height of the colony could be obtained. 



Desmosotphus ungtjiculata, Bust*. (PL XVII. figs. 5-7.) 



TropTiosome. — Colony consisting of pinnate stems which spring 

 at short intervals from a creeping filiform stolon ; pinnge alter- 

 nate. Hydrothecse with the margin of the orifice produced into 

 a long and wide posterior lip and a much shorter and narrower 

 anterior lip ; those of the pinnae adnate to one another by about 

 two thirds of the height of their opposed sides, those of the stem 

 distinct. 



Gonosome. — Gronangia springing each from an infcernode of the 

 stem ; oval, with a circular orifice raised on a very narrow collar. 



Locality. Adelaide. 



I believe that the hydroid here described must be referred 

 to Sertularia tmguiculata, Busk. The specimen in the col- 

 lection is apparently an example of a young colony, and attains 

 a height of somewhat more than half an inch. The two lips into 

 which the margin of the hydrotheca is produced bear some re- 

 semblance to the mandibles of a bird. Of these lips the posterior 

 is broad and long and terminates in a blunt point, while the ante- 

 rior, though nearly of the same shape, is very much smaller, 

 and is hidden by the other in the posterior view of the internode. 

 The internodes of the pinnae are short, and the consecutive 

 pairs of hydrothecsa are here closely approximate. These hydro- 

 thecse lie entirely on the front of the internode, and in each pair 

 are adnate to one another by the greater part of their opposed 

 sides. The hydrothecse of the stem also lie upon the front aspect 

 of their internode, but here they are quite distinct from one 

 another. 



The stem is divided into internodes carrying each a single 

 pinna, which springs alternately from the right and left in conse- 

 cutive internodes, or else carrying two alternate pinnae ; the latter 

 condition being chiefly that of the internodes near the base of 

 the stem. 



While the disposition of the hydrothecse of the pinnae is thus 

 quite that of a typical Desmoscyplius, the hydrothecae of the stem 

 more nearly reproduce the characters of Thuiaria. 



The specimen extends over the surface of a seaweed, which it 

 thickly covers with a diminutive fern-like growth. 



The same species has also been described and figured by Balef, 



* Busk, in Voyage of the ' Rattlesnake.' 



t Oat. of Austi'alian Hydroid Zoophytes, p. 76. 



