1889.] NATURAL SCIENCES OF PHILADELPHIA. 73 



acter of Vioa is that it is parasitic, and lives in perforations of shells 

 and stones (Die Spongien der Adriatisehen Meeres, 1862, p. 40). 

 He also describes what he considers to be a new genus of sponges, 

 Papillina, which, except in name, I cannot distinguish from Cliona. 

 The species Papillina suberea he describes as yellow with numerous 

 warts on the surface and with only pin-like spicules. Bowerbank 

 regards it the same as Baphyrus Griffithsii, corresponding with the 

 Halichondria celata of Johnston, who described it as a variety of 

 Dr. Grant's Cliona celata, and this is admitted by Schmidt (Spongien 

 der Atlantischen Gebietes, 1870, 77). The latter further describes 

 a cushion-like (polsterformiger) Papillina, from the coast of Florida, 

 which likewise appears to be a Cliona. 



As the massive form of Halichondria celata of Johnston, synony- 

 mous with Baphyrus Griffithsii of Bowerbank and Papillina suberea 

 of Schmidt, accords in color and structure, and in the form and size 

 of its silicious spicules, with Cliona celata, it seems to be related to 

 this, as our massive Cliona sulphurea is to the boring form of the 

 ovster and clam. It remains to determine whether our boring-sponge 

 of the oyster is the same species as that of European seas. So far 

 as we may judge from the descriptions of the European sponge in 

 comparison with ours they appear to be identical in color, form, 1 

 structure and habits. Both also have but one kind and form of 

 silicious spicules. But in these, if the records are correct, we find a 

 very considerable difference in size. Grant, Hancock, Bowerbank, 

 and Lieberkuhn give as the size of the spicules of Cliona celata, 

 about sVth of an inch, while in all our forms of Cliona, in the oyster 

 and clam and in the largest massive varieties, the size of the spicules 

 is only about sVth of an inch. Moreover, if the observation of 

 Mr. Hancock is correct and I have not erred in my own, there is 

 still a more remarkable difference. 



In the boring-sponge of our oyster and clam I could detect no 

 trace of the silicious, hexagonal granules, which Mr. Hancock re- 

 gards as the instruments of boring of Cliona celata. In the posi- 

 tion indicated for these granules, in repeated examinations, I could 

 find nothing but a few scattered irregular particles of quartz sand. 

 The onlv distinction then, if future observations prove them 

 really to exist, between Cliona sulphurea and Cliona celata, are the 

 considerably longer, silicious, pin-like spicules of the latter and the 

 presence in the boring form of additional haxagonal, silicious gran- 

 ules; otherwise both would pertain to the single species Cliona celata. 



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