254 ANATOMY AND PHYSIOLOGY 



FIG. 



161. CLAVATED SUBSPHERO-STELLATE. X 1060 linear. 



The cylindrical radii having the distal terminations 

 more or less dilated, and the central basal sphere 

 not exceeding in diameter the length of one of the 

 radii. This form of spiculum is very abundant in 

 Tethea Ligalli, Bowerbank, MS., intermingled with 

 attenuato-cylindro-stellate spicula. 



162. CLAVATED SPHERO-STELLATE. X 1060 linear. The 



cylindrical radii having the distal terminations 

 dilated, and the central basal sphere greater in its 

 diameter than the length of one of the rays. This 

 spiculum is abundant in the sarcode of the dermal 

 and interstitial membranes of Geodia Barretti, 

 Bowerbank, MS. It is very minute, the extreme 

 diameter varying from g^th to T ^th of an inch. 

 Page 52. 



. ELONGO-ATTENUATO-STELLATK, from Tethea muricata, 

 Bowerbank, MS. X 1060 linear. See Fig. 35, 

 Plate I, and corresponding description. 



163. ARBORESCENT ELONGO-SUBSPHERO-STELLATE. X 106 



linear. (See Plate X.) Having the radii spring- 

 ing from a dilated and elongated common base of 

 about the dimensions of two subsphero-stellate 

 spicula, partially fused together. 

 This remarkable form occurs abundantly in Geodia 

 carinata, Bowerbank, MS., from the South Sea. The 

 nucleus, whence the radii proceed, is always more or 

 less elongated, but is not usually so much dilated as 

 in the specimen figured. The arborescent character 

 of the distal terminations of the radii is also very 

 variable. 



164. SUBSPHERO-STELLATE. X 660 linear. Having the 



radii more or less acutely conical, and as long or 

 longer than the diameter of the central basal sphere: 

 from Tethea Ingalli, Bowerbank, MS. In this 

 sponge and in other species this form occasionally 

 presents a very gradual transition from the purely 

 stellate form to the full subsphero-stellate one, in 



