CRISTATELLA MUCEDO. 71 



" Enjoy and live like man, 



And the minutest throb 

 That through their frame diffuses 



The slightest, faintest motion 



Is fixed and indispensable, 



As the majestic laws 



That rule yon rolling orbs." 

 The colony, or " coencecium," (to use the proper term, 

 signifying "common house,") is not stationary. Unlike some 

 other species it can shift its locality. The whole mass is 

 oval, with a convex upper surface studded with apertures, 

 through which the beautiful zooids protrude. They inhabit the 

 outer margin of the coenoecium in three regular concentric series 

 of apertures, alternating one with another; the interior oval 

 space is devoid of orifices. This description is according to 

 Allman, and its features can be tolerably well seen in the drawing, 

 copied from his splendid monograph. The under surface of the 

 coenoecium is stated to be well adapted for the purpose of 

 locomotion, resembling in its central portion the foot of a 

 gasteropodous mollusc. From the longitudinal disc or foot, 

 which is contractile, a large flattened margin extends beyond the 

 external series of orifices ; and a regular arrangement of tubes 

 can be seen within the outer membrane, but having no external 

 openings. Towards the end of the season the central upper 

 portion of the coenoecium is studded with dark circular bodies ; 

 these are the " statoblasts," which are destined to form the 

 colonies of the succeeding season, and which have been observed 

 only in Cristatella and one other species. They are orbicular, 

 the central portion being surrounded with an annulus of hexagonal 

 cells. The interior and thicker orbicular part is of a rich reddish 

 brown, decorated with dark spots, while the annulus is of a 

 yellowish tinge. In its earlier stages it is surrounded with cilia, 

 afterwards with a membrane; but between the junction of the 

 annulus and the central disc there subsequently grows a number 

 of barbed organs, which lengthen beyond the annulus, and 

 eventually tear up and destroy the outer membrane. No orifice 

 has been discovered in the parent animal by which these 

 statoblasts are expelled, and it is presumed on very good evidence 



