I 



HYDROIDA. — BALE. 291 



description. The gonothecse, however, are narrower than 

 those figured ; here and there one is seen which in lateral 

 view agrees with the figure, but this is exceptional ; while 

 the frontal aspect is far narrower, its width being usually 

 just about the same as that of the pinna with its hydro thecae, 

 and the same width is maintained throughout, except just 

 at the base. 



The hydrothecse are somewhat similar to those of S. 

 divaricata, but are of narrower proportions, more regularly 

 curved, and with the aperture smaller. In most cases 

 regeneration has occurred repeatedly, and the later peristomes 

 are generally decidedly smaller than the primary one, as 

 well as slighter in texture. 



There are no nodes, or very few, in the pinnae ; the hydro- 

 thecae being in long uninterrupted series, such as were 

 formerly considered characteristic of the genus Thuiaria. 



Locs. — Oyster Bay, Tasmania, 60 fathoms. 



Shoalhaven Bight, New South Wales, 15-45 fathoms. 



Family PLUMULARIID^. 



This is by far the most important family represented in 

 the collections, whether regarded in relation to the variety 

 of the forms observ^ed, or to the beauty and luxuriance of 

 many of the species, or to the abundance of the colonies. 

 Several species, both among the Statoplea and the Eleuther- 

 oplea, attain over a foot in height, and three or four reach 

 two feet, possibly more. Out of thirty species the genera 

 Nemertesia, Kirchewpaueria, and Halicornopsis are repre- 

 sented by one each ; the rest, with one exception, are divided 

 among the genera Plumularia, Aglaophenia (with Thecocarpus) 

 and Halicornaria. The exception is a small form closely 

 allied to Cladocarpus, for which a new genus is proposed 

 under the name Cladocarpella. 



Genus Plumularia, Lamarck. 



The genus Plumularia, as I have been used to regard it, 

 would include a number of forms which, by Allman and 

 others, were considered to be types of distinct genera. Such 

 are Antennella, Acanthella, Heteroplon, and Halopteris. I 

 have already referred to Antennella, which is a convenient 

 division, but subject to the disadvantage that in studying a 

 newly discovered specimen one cannot be certain whether 

 it is a true Antennella or merely an unbranched form of some, 

 pinnate species. 



