OF THE SPONGIAD^. 269 



Fig. 



in the course of their further development they 

 assume a moniUiform appearance, as represented 

 by Fig. 239, and in their adult state are verticil- 

 lately spined, as represented by Mg. 238. 



240. IiVFiiATO-ACEEATE, with incissurate terminations. 



X 660 linear. — From Hymeraphia verticillata, 

 Bowerbank. A terminal portion only of this spi- 

 culum is represented by the figure, the incissurate 

 character being the only novelty in the form. The 

 incissuration varies in degree to a considerable ex- 

 tent in different spicula, in some cases being very 

 slightly produced, in others rather beyond that re- 

 presented by the figure. The rudiments of a third 

 ray are sometimes apparent. This form is an aux- 

 iliary skeleton spiculum. They are found thickly 

 clustered round the primary spicala of the skeleton. 

 They differ essentially from porrecto- tern ate spicula 

 in having both ends cleft or radiate, which is never 

 the case in any of the ordinary temate forms. 



SPICULA, THE POSITiONS OF WHICH ARE UNKNOWN. 



241. BlRECURVO-QUATEHNATE, MEDIALLT SPINED. Sponge 



unknown, X 660 linear, — Probably an internal 

 defensive spiculum. 



242. Spinulato-ensiform, from a parasitical sponge from 



Western Australia. X 130 linear. — I obtained 

 this singular form from a parasitical sponge from 

 Western Australia. This curious sponge, in the 

 formation of its skeleton, appears to have appro- 

 priated the spicula of every other kind of sponge 

 that came within its reach. 



243. ACUATE : BASALLY RECTANGULATED. X 150 linear. 



— 1 obtained this spiculum from the spongeous 

 matter scraped from the base of Oculina rosea, 

 by a dealer in the process of cleaning the coral. 

 It is not a malformation, as there are several 



