Bibliographical Notices. 229 



been retained distinct from the Gymnoblastea. Seven species re- 

 presenting six genera, Tuhulana with two species, and Tibiana, 

 Etidendrium, Pennaria, CerateUa, and Dehitella with one each, 

 belong to the Gymnoblastea ; while the other species, representing 

 seventeen genera, are forms of the Calyptoblastea, namely : — 



Campaniilaria . . 12 species. Pasythea 2 species. 



Obelia 1 ,, Idia 1 „ 



Eucopella 1 „ Thuiaria 3 „ 



Lineolaria .... 2 „ Plumularia , ... 22 „ 



Lafoea 1 ,, Antennularia .... 2 „ 



Halecium 1 „ Aglaoplienia .... 22 „ 



Sei-tulm-ia .... 40 „ Halicornaria .... 10 ,, 



DiljJiasia 5 „ Hcdicornopsis .... 1 „ 



Serttdarella .... 10 „ 



Among the new species which have been described in the Cata- 

 logue is one of the singular genus Lineolaria (consisting now of 

 two species), which was originally founded by the Eev. Thomas 

 Hincks for a most curious Australian hydroid from Port Phillip, 

 and for which Prof. Allman has since constituted a new family. 



In the definition of the geiius SertulaHa Mr. Bale insists on the 

 paired condition of the hydrothecse as being an essential character 

 which serves as an important distinction between this genus and 

 its allies Sertularella and Thuiaria ; and he points out that the 

 genus PesmoscypJius, Allman, is not really distinct from SertuJaria, 



A most remarkable variety of the Sertidaria unguiculata. Busk, 

 which throws considerable light on the affinities of the genus, is 

 described, in which not only do some pinnae bear as many as twenty- 

 four pairs of hydrothecae on the longest internodes, closely adnate 

 throughout the greater pai't of their length, while towards the end 

 of the pinnae the ordinary Sertularian type is found, but also on 

 some of the pinnae there is present a third series of hydrothecse 

 running for some distance along the front of the first internode. 



Very valuable critical remarks are made on the definition of the 

 genus Thuiaria. Formerly the adnate condition of the hydrothecge 

 was a sufiicient distinction from Sertwlaria ; but this has had to 

 be given up with the increase of our knowledge of their forms, and 

 the distinction was based by Prof. Allman on the nature of the 

 jointing of the hydrocaulus and the number of hydrothecse on the 

 internode. Mr. Bale points out that this again must be abandoned, 

 and that the real distinction is to be found in the fact, that while 

 in Sertidaria the hydrothecae are arranged in pairs, in Thuiaria they 

 form two series, those on opposite sides of the hydrocaulus having 

 no special relation to each other. 



Correspondingly valuable remarks are made on various points 

 under the genera Plumularia, Aglaophenia, and Halicornaria ; but 

 it is to be regretted that the essential characteristics of Plumularia 

 and Antenmdaria have not been subjected to the same critical exa- 

 mination which marks many of the other genera. 



In this short notice it has been impossible to do full justice to 

 Mr. Bale's admirable work ; and the reader must be referred to the 

 work itself for further information. 



