MIMOSELLID^E. 555 



exhibits the same structure, his name, of course, has pre- 

 cedence. 



HABITAT. On stones and stems of Algse between tide- 

 marks, and on shell from moderately deep water. 



LOCALITIES. Salcombe Bay, on Flustrapapyracea; Ilf'ra- 

 combe, on the Capstone, not uncommon ; dredged off' the 

 Mr of Man (T. H.) 



Family IX. Mimosellidae. 



ZOOSCIA contracted below, movable, deciduous, with an 

 aperture on the ventral side. 



Genus MIMOSELLA, Hincks. 



Der. Dim. of Mimosa, the Sensitive Plant. 

 MIMOSELLA, Hincks, Ann. N. H. 1851 : Landsborough : Heller : &c. 



GENERIC CHARACTER. ZOARIUM phytoid, regularly 

 jointed, consisting of a creeping tubular base and erect 

 shoots, much and irregularly branched, branches opposite. 

 ZOOZCIA ovate, biserial, opposite, attached to the sides of the 

 stem by a basal joint, by means of which they can be moved 

 to and fro and folded together. POLYPIDES with a small 

 number of tentacles ; without a gizzard. 



MIMOSELLA is separated from the Valkeriidce by its 

 movable cells, and more especially by the large aperture 

 on the ventral aspect of the zooecium. The latter occupies 

 almost the whole of the front side, extending from the 

 top nearly to the base of the cell. It is closed by a thin 

 membranous covering, and, when the polypide is retracted, 

 ]- \. iy inoonspicnoni and may most readily escape obscr- 



