50 Cincinnati Society of Natural History. 



of which are pierced with holes, " foramina." The gelatinous 

 body mass is protruded in the form of filaments from the 

 numerous orifices. 



At the present time these organisms are wonderfully 

 abundant. D'Orbigny estimated that an ounce of sand from 

 the Antilles contained 3,Soo,ooo individuals. In pa.st geologi- 

 cal time the}- were equally numerous, in some places forming 

 extensive series of rocks. In the Paris basin 58,000 have 

 been counted in a cubic inch, or 3,000,000,000 in a cubic yard. 



At present but one genus is referred to the order, described 

 below. It is placed here upon the authority of Nicholson and 

 Ivydekker's Manual of Palaeontology, vol. i, 1889, p. 128. 



GiRVANELLiA, Nich. & Ethr., Jr., 1878. 



Rounded or oval bodies, composed of "microscopic tubuli, 

 with arenaceous or calcareous (?) walls, flexuous or contorted, 

 circular in section, forming loosely compacted masses. The 

 tubes apparently single cylinders, without perforations in their 

 sides, and destitute of internal partitions or other structures 

 of a similar kind." (Fossils of the Girvan District, 1878, p. 23.) 



Remarks. — As synonyms of this genus, as described above, 

 should probably be placed Strcphochctus, Seely, 1885, and 

 Strcptospongia, Ulrich, 1889. The following is Seely's descrip- 

 tion of Streplwchctiis : " A free calcareous sponge, showing in 

 structure concentric layers, composed of minute twining 

 canals." (Am. Jour. Science, 3d ser., vol. 30, p. 357.) 



This name was proposed for certain spongoid bodies found 

 in the Chaz}- rocks of Vermont. Its main character, as given 

 in the meager description, is in the twining canals. In a later 

 paper (Am. Jour. Science, 3d ser., vol. 32, 1886, p. 34), Pro- 

 fessor Seely says: "The appearance of the members of the 

 genus may be represented by the smaller fruits, currants, 

 gooseberries and cherries, distributed through a paste of 

 oolitic, fragmental or sub-crystalline material. These, in most 

 cases, have been left in a crushed or torn condition. In 

 weathered specimens they show a concentric structure, more 

 or less regular, which is helpful in distinguishing the genus." 

 This description corresponds exactly with the figures of 

 (ihvanenia. 



Mr. Ulrich's genus, Str(plo.spo>ii^ia, is also founded upon a 

 form with twisted canals. The description .says that in trans- 



