G. SPONGIA. 177 



ROD-SHAPED. 



117. Spongia virgidtosa. Stem hard, upright, and 

 unequally cylindrical ; branches stretching out in the 

 form of rods, upright, spriggy, unequal, and termina- 

 ting in obtuse points ; surface velvety and osculated. 



Var. B. Branches flexuous and diverging. 

 Seas of the north of Europe. 



LONG-POINTED. 



118. Spongia longicuspis. Base forming a coarse 

 trellis, supporting from six to nine long upright 

 branches, which are sometimes coalescent, forming 

 slender digitations, or long points. 



Southern seas* 



asparagus. 



119. Spongia asparagus. Upright and branching; 

 branches in the form of rods, unequally cylindrical, 

 and rather obtuse at the summits ; incrustation not 

 thick ; oscules almost disposed in series. 



Seas of Australasia. 



DICHOTOMOUS. 



120. Spongia dkhotoma. Upright; branches cy- 

 lindrical, hairy, and lateral. 



Var. B. Branches tortuous, frequently anasto- 

 mosed. 



Sea of Norway, and Mediterranean. 



BRISTLED. 



121. Spongia echidncca. Corky and branching ; 

 Cor. z 



