82 



ACCOUNT OF BRITISH SPONGES. 



6. Dichotoma. Branched, erect, subcylindric, to- 

 mentose, and covered with small pores. 



Spongia dichotoma. Ellis, Zooph. p. 187. 6. — PhiL 

 Trans. 55. p. 289. t. 11. f. 1. {Ellis.) Lin. Syst. 

 p. \2m.—Berken. p. 213— Gme/. p. 3822. 



Plate vi. fig. 1. 



Brown, with long erect dichotomous straight 

 branches, smaller at their smnmit : at the divari- 

 cation of the branches it spreads a little, becom- 

 ing compressed, but never so much as S. oculata ; 

 from which it also differs in the superior length 

 and straightness of the branches ; the texture is 

 also more firm and less woolly. The dichotomaj 

 like the oculata, originates from a compact lig- 

 neous stalk, an inch or two in length, but the 

 branches are truly dichotomous, and they never 

 terminate in more than a fork, and most frequent- 

 ly in a single point ; whereas the oculata is much 

 more complicated in its branches, which are more 

 compressed, and sometimes inosculate, and their 

 tips become digitated in older specimens ; in some 

 the ends are palmated, from which issue four or 

 five fingers. In both these species, numerous 

 branches arise together from the top of the main 

 stalk *. in the dichotoma^ the first subdivision or 

 offset from a main branch, commences close to 

 the base, and another divarication takes place at 

 the distance of two or three inches ; but many of 

 the main branches have only a lower divarication^ 

 and from thence extend nine or ten inches per» 



