32 ARTHUR DENDY. 



from the parent sponge. This is represented, twice the natural 

 size, in fig. 5. The gastral cavity of the young sponge is still 

 connected with that of the mother by a very evident aperture, 

 and it is interesting to notice that in this case the osculum is 

 distinctly constricted, so that the bud has the typical Sycon 

 form. 



The So-called Family Teichonidae. 



The very artificial group of sponges now generally known 

 under the name Teichonidae has been unfortunate from first 

 to last. It was not even christened properly, for the title of 

 Mr. Carter's original paper (3) is printed "On Teichonia, a 

 New Family of Calcareous Sponges, with Descriptions of Two 

 Species ;" while subsequently, on the same page, the name 

 Teichonellidse is given to the new family, which is concisely 

 diagnosed as '^Wallate." Then the genus Teichonella is 

 diagnosed as follows: ^^ Vallate or foliate, without cloaca. 

 Vents numerous, confined to the margin or general on one side 

 of the lamina only ; naked." 



Teichonella prolifera is described as the first species of 

 the genus, and in the same paper Grantia labyrinthica is 

 described as a second species. Subsequently, as I have already 

 said, Mr. Carter withdrew Grantia labyrinthica from the 

 genus Teichonella, and recognised its true position amongst 

 the Sycons. 



Now we see upon what slight foundations spongologists 

 build their edifices. Polejaeff (8) adopts the new family, 

 altering the name, however, to Teichonidse. He states that 

 the main character of the family consists in the differentiation 

 of the outer surface into two planes, one bearing oscula, the 

 other pores exclusively ; and he enters into a curious specula- 

 tion as to whether a Teichonid is " a colony with dislocated 

 oscula and pores/' whatever that may be. But what authority 

 had Polejaeff for stating that the outer surface was differen- 

 tiated into two planes, one bearing oscula and the other pores ? 

 Mr. Carter never said so. His diagnosis of the family is 

 " vallate,'^ while even his generic diagnosis says nothing about 



