OF THK SPONGIADiE. 283 



ILLUSTRATIONS OF THE GENERA. 



Order I. — Calcarea. 

 Pig. 



345. Grantia. a longitudinal section of a portion of one 



side of a specimen of Grantia ciliata, Johnston, ex- 

 hibiting the structure and mode of disposition of 

 the interstitial cells, x 108 linear. See also Fig. 

 312, PI. XXI, for the interstitial cells of G. com- 

 pressa. Pages 27, 119, and 163. 



346. A group of two Grantia^ on a Zoophyte, natural size ; 



a, G. ciliata, 6, G. compressa. Page 163. 



547. Leccosolenia botrtoides, Bowerbank. Two 

 branches exhibiting the simple fistulose structure 

 of the sponge. X 50 linear. Page 164. 



348. A small group of the sponges L. hotryoides, natural 

 size. Page 164. 



349. — Leucogypsia Gossei, Bowerbank. A section at 

 right angles to the surface, exhibiting the mass of 

 irregular interstitial structure. X 50 linear. Page 

 166. 



350. A specimen of L. Gossei, natural size, exhibiting the 

 form and position of the oscula. Page 166. 



351. — Letjconia NiVEA, Bowerbank. A longitudinal sec- 

 tion of one of the mammiform portions, exhibiting 

 one of the great cloacal cavities of the sponge and 

 its internal defensive spicula. X 50 linear. Page 

 165. 



352. An averaged-sized specimen of L. nivea, exhibiting 

 the lobular form of the cloacal portions of the 

 sponge and the position of the mouths of the 

 cloacae. Page 165. 



