548 TTHTICELLIDJC. 



Genus HIPPURARIA, Busk. 



Per. From ITTTTO*, a horse, and oi'pa, a tail. 



HiPPt-RARiA, Busk, Proc. Zool. Soc. Loud. 1874. 

 LAGENEU.A (part.), Joliot. 



GENERIC CHARACTER. STEM repent or erect, tubular, 

 jointed, nodular. ZOCECIA with a membranous area on the 

 front or ventral side, attached to a peduncle by a movable 

 joint, and disposed in whorls or groups at the nodes. 



THE generic character is framed to include the form 

 described by Joliet under the name of Lagenella nutans*, 

 which has a creeping nodular stem, on which the zooecia 

 are placed in groups at the nodes, instead of being dis- 

 posed round an erect stem in whorls, as in the species 

 characterized by Busk. The recent observations of G. O. 

 Sars on Triticella enable us to interpret this remarkable 

 form, and throw light on several points in its structure, 

 which Mr. Busk, having only a single, imperfectly pre- 

 served specimen before him, was unable to determine. 



Hippuraria appears to be a clustered Triticella. Its cell 

 seems in most respects to resemble so exactly that of the 

 latter genus, that we are perhaps warranted in supposing 

 that the appearances which led Mr. Busk to describe it as 

 composed of two distinct compartments may have been 

 due to the condition of his specimen. If the zooecium of 

 Hippuraria is indeed two-chambered, this character will 

 make it the type of a separate family. 



* This species occurs on Vesicularia spinosa and the leaves of Kito- 

 pJiyllum. 



