194 



D 



ICTYOSPONfUD/E. 



Figure 43. Spicules of Physospongia CoUetti ; frag- 

 ments iif cli'iiies, anchorate clavulos and echinate hex- 

 attins, etc. XG5. (J. M. C.) 



shown in figs. 5 and 6''of the phite cited. The apertnre of the cup appears 

 to be smooth and its margin regular and even, without processes or spicular 

 projections. 



Sheleton. As in Phijmspon<jki Dawsoni, the vertical bundles in this 

 species are composed of a great number of smooth rods, there being associated 



with them anchors and clemes. In the 

 material imder examination the spicular 

 structure is not very satisfactorily retained, 

 but it Avould seem as if these anchorate 

 and clemate rods were compai-atively less 

 abundant than in P. Dawsoni, and they 

 prove to be of somewhat smaller size. The 

 predominant pentactins are of large size and 

 strongly echinate. It is presumed that 

 these lay at the angles of the quadrules and their abundance is in contrast to 



the comparatively rai'e 

 occurrence and small 

 size of similar bodies 

 in P. Dawsoni. The 

 surface of the nodes 

 and depressions is 

 very minutely and 

 retangulai'ly reticu- 

 lated but so little of 

 the spicular fi-ame- 

 work over those areas 

 has been preserved 

 that only the large 

 imibel (fig. 44) can 

 be referred thereto. 

 It has been observed 

 that although the 

 specimens of P. Daw- 

 soni have afforded 

 much moi'e satisfac- 

 tory means of study- 



FIODEK 44. Spicules of P;ii/soiil)on{/ia CoHc»(. x400. (.f. M. C.) ing thc SplCUlar clC- 



ments of the skeleton, no umbels have been found in that species. Presum- 

 ably in P. Colletti spicular tufts were present at the intersection of the 



