CELLEPORHLE. 477 



and one-fourth the breadth, of the cell. The mouth is longitudinally 

 oval, rather large, and with a thickened rim. At a short distance 

 from the proximal lip is a small pearly tubercle, which is larger in 

 one cell than in another. The branching is at right angles, and the 

 cells arise immediately opposite the mouth." 



Fig. 87. 



" This tubercle is very different from anything ever observed in 

 H. lanceolatum, and constitutes it a distinct species." R. Q. Couch. 



GEMELLAEIA LORICULATA, p. 293. The aperture in the cell 

 through which the polype extrudes its tentacula, is formed by a 

 valvular membrane with a transverse slit. It is comparatively small. 

 There is " also a remarkable orifice at the back part of the cell ; pro- 

 bably through it the polype is connected with the vital axis. Upon 

 a very few cells is a small adnate tube, with a spreading tip on the 

 anterior side. I could not determine whether it was extrinsic to the 

 polypidom or not." F. W. L. Thomas, R. N. 



CELLEPORID^E. 



LEPRALIA HASSALLII, p. 304. " This is, I fancy, more like a Cel- 

 lepora, from the cells being heaped upon each other, like C. pumi- 

 cosa. I find it plentiful on various algae, especially on the roots of 

 Laminaria digitata." C. W. Peach. 



Mr. Thomas has arrived at the conclusion that the Lepralise in 

 general possess the " Bird's head processes ;" but in them, " the skull 

 is down wards, and the movable bill uppermost ;" that those which 

 have the largest ovaries have the bills most developed ; that the po- 

 sition of these organs is variable in different species, and will present 

 the best specific characters, and they are not (?) present on those in- 



