I)lCTYOSPONGID^£. 



363 



the angles of some of the quadrules ; but in its general aspect smooth, without 



prism-faces, nodes, or other irregularities. 



Reticulum characterized by very broad and strong vertical bundles or 



lateral ia. On the exposed surface of the specimen there are seven of these 



at wide but unequal intervals. 



These bundles reach almost or 



quite to the lower extremity of 



the specimen, spreading gradually 



outward. An interesting struc- 

 ■ 



tural feature is the intercalation 

 of other bundles in two of the 

 interspaces at a considerable dis- 

 tance above the base, and both 

 these and the primary bundles 

 increase in width upward. All 

 the bundles are composed of a 

 large number of stout, cylindrical, 

 continuous rods, varying some- 

 what in size, and with them are 

 numerous denies of so great size 

 as to be visible to the naked eye. 

 The latter appear to be restricted 

 to the middle and upper extent of 

 the bundles, no trace of them hav- 

 ing been found on the lower part 

 of the specimen, and on some of 

 the intercalary bundles they are 

 not to be seen at all. These 

 clemes are similar to those occur- 

 ring in Physospongia Dawsoni 

 and P. Colleti, though very much 

 larger. The direction of their 

 teeth is, however, directly the 

 reverse of that in all other known 

 instances. This peculiar fact at 

 first suggested the possibility of 

 an error in the orientation of some 

 of the specimens but repeated re- 

 views of our observations seem to F t f F '° n " £ , Lvrodictva R ° m ; naeri - 



Fragment of one or the large reversed cleme», a dlactine rod, crucl- 



dlSpel any doubt Of their aCCliraCV formB P lcule * of v »rlous sizes and theupperiurfa.ee of a very small umbel. 

 * v J • X400. i J. M. C.) 



