474 



Report of the State Geologist. 



cell occupying the center, the mass growing in size by the in- 

 crease of the cells occupying the border. 



Left-hand figure. Bicellaria ciliata. Free embryo, oral face. 



Right-hand figure. Cauda repens. Free embryo, profile view, a, Pharynx; b, Opening of the 

 cavity ; c, Stomach ; d, Mouth of the gastrula ; e, Flagellum ; g, Aboral mesoderm; I, Intestine. 



Statobla^sts. 



In the Hippocrepian forms, there is still another mode of repro- 

 duction. At certain seasons of the year peculiar bodies occur 

 attached to the funiculus (fig. 18, z) or lying loose in the perigas- 

 tric space, to which Allman has given the name of statoblasts, 

 figs. 30, 3 1 . They are lenticular bodies, varying in different genera 

 from orbicular to elongate oval, and enclosed in a horny shell, 

 consisting of two concavo-convex discs, united at their margins 

 by a ring, which is of a different structure from the discs. 



The statoblasts have erroneously been described as an egg, but 

 are considered by Allman to be a form of bud. They are devel- 

 oped on the funiculus and may be seen on that organ in various 

 stages of growth. 



The following account of them is taken from Allman's 

 <' Fresh-Water Polyzoa." 



" In LoPHOPUs I have succeeded in following them through 

 their various stages of early development. Their first appear, 

 ance here is in the form of little swellings on the funiculus, 

 consisting of a mass of minute cells, surrounded by a dense 

 layer, continuous with the surface of the funiculus. The swell- 

 ing now increases in size and assumes a more regularly oval 

 form, whilst its contents appear more uniformly granular, and 



