770 SOME NEW AND RARE HYDROIDA IN THE AUSTRALIAN MUSEUM, 



often wanting in some of the calyoles. There is a conspicuous 

 oblique joint at the base of the lowest internode of each shoot. 



Mr. Clarke's figure and description* agi'ee with our s))ecLmens, 

 except that he represents the teeth of the hydrotheca-margin for 

 the most part above and below the aperture rather than at the 

 sides ; but one or two of his figures approximate to the present 

 form in this respect, and the other details being precisely similai-, 

 1 have little doubt that the identification is correct. The gono- 

 thecae were not present in Mr. Clarke's specimens. 



Sertularia elongata, Lanix, 

 Coogee. — A small specimen with some of the cauline internode* 

 bearing only a puir of hydrothecae and no pinnas. 



Pasythea quadridentata, Ellis and Solander. 



(Plate XIV., figs. 6-7). 



Coogee ; Bondi. 



Of these specimens, that from Coogee most resemVjles tlie typp, 

 but is distinguished by the internodes being less elongated, so that 

 the sets of hydrothecse are close together. The Bondi specimens 

 are peculiar, a considerable proportion of the internodes bearing 

 only a single pair of calycles each ; indeed some of the shoots are 

 so arranged throughout, and thus differ in no respect from a 

 typical Sertularia. The apertures of the calycles are directed 

 more to the front than in the tyjie, and have blunter teeth, and 

 the hydrothecae generally, when not united in sets, strongly 

 resemble those of some forms of S. australis and S. loculosa; and 

 as in the latter species the joints between the internodes are in 

 some cases simple and inconspicuous, while in others the upper 

 intex'node is produced downwards to a point, and the lower is 

 similarly produced upward behind it. 



I observed a single gonotheca, which was sub-globular, with 

 about four not very prominent trausverse annulations, and a large 

 ajjerture with an elevated neck and an operculum. 



♦Report on the Hydroida collected during the exploration of the Gulf 

 Stream and Gulf of M exico, by Alexander Aga.ssiz 1877-78. (Bull. Mus. 

 Comp. Zool., Cambridge U.S., Vol. V Ko. 10) 



