Mr. H. J. Carter on a Lacustrine Bryozoon allied to Flustra. 171 



by a wide mouth into the pyloric half of a large irregularly 

 ovoid stomach. Stomach lined or surrounded (?) throughout 

 with a layer of hepatic (?) cells, and contracted towards its 

 pyloric end, where it is in continuation with the small intes- 

 tine. Small intestine short, followed by a globular, some- 

 times elliptically dilated, portion (corresj)onding to the large 

 intestine of higlier animals (?)), also lined or surrounded with 

 cells, but diiFering in appearance from those of the stomach ; 

 terminating in a contracted, rectal portion, which opens into 

 the buccal sheath (when inverted). Retractor muscle attached 

 to the posterior extremity of the cell, and around the posterior 

 part of the buccal sheath (when inverted). 



Obs. — Besides the retractor muscle, there are of course many 

 others which pass from the lining membrane of the cell, and 

 probably the cell itself, to the different visceral organs ; but the 

 torn state of these, from the contracting eflFect of the spirit in 

 which the polypidom was preserved, prevents my describing and 

 delineating them accurately. The peritoneal cavity, too, in most 

 instances contained bunches of globular cells of different sizes, 

 and some fusiform bodies, which might have been procreative 

 elements ; but not having observed them in their li\ing state, 

 I am unable to add more respecting them. I could discover 

 neither testicle nor ovary; nor have I been able to make out 

 the exact number of the tentacula, for the same reason. The 

 latter, how^ever, with their delicate buccal sheath, being in dif- 

 ferent degrees of extrusion in several of the cells respectively, it 

 was easy to see that the plaited part preceded the extension of 

 the tentacula, as in the other freshwater Bryozoa, and in Bower- 

 bankia, to which latter the organology generally, as well as 

 closely, corresponds. 



EXPLANATION OF PLATE VIL 



Fig. I. Hislopia lacustris, polypan,', proportionally magnified. Natural 

 size of cells l-2yth of an inch long. 



Fig. 2. Ditto, ditto, with animal, ditto, shotting a, a, a, a, margins of cell; 

 b, aperture closed by three valves, supported on a circular neck, 

 surrounded by a horny border bearing four spines ; c, lining 

 membrane ; d, d, d, d, stolons passing through their respective 

 holes ; e, buccal sheath enclosing tentacula ; f, pharynx ; g, oeso- 

 phagus ; k, gizzard ; i, stomach ; k, small intestine ; k', large 

 intestine; /, rectum ; m, retractor muscle; n,n,n, other muscles; 

 s, spherical and fusiform cells. 



Fig. 3. Ditto, ditto, ditto, with tentacula and buccal sheath partly extruded : 

 a, buccal sheath, showing the plaited portion ; b, visceral organs 

 drawn up towards the aperture; c, retractor muscle, also ex- 

 tended. 



Bombay, 9th Jan. 1858. 



