234 Miscellaneous. 



groups of birds ; and hence a new subclass, Odontomithes, is proposed 

 for them. The order may be called Ichthyornithes. 



The species lately described by the writer as Iclitliyornis celer 

 also had biconcave vertebrae and probably teeth. It proves to be 

 generically chstinct from tbe type species of tliis group, and hence 

 may be named Apatornis celer, Marsh. It was about the same size 

 as Iclithyoniis dispar, but of more slender proportions. The geolo- 

 gical horizon of both species was essentially the same. The only re- 

 mains of them at present known are in the museum of Yale College. 



The fortunate discovery of these interesting fossils is an important 

 gain to palaeontology, and does much to break down the old distinc- 

 tions between Birds and Eeptiles, which the Archaeopteryx has so 

 materially diminished. It is quite probable that that bird, likewise, 

 luid teeth and biconcave vertebrae, with its free metacarpals and 

 elongated tail. — Amer.Journ. of Science and Arts, vol. \., Feb. 1873, 



On two new Free Sponges from Singapore. 

 By Dr. J. E. Geay, F.R.S. &c. 



Dr. A. B. Meyer has sent to the British Museum five specimens of 

 free sponges (four of them belonging to one species, and the 

 other to a separate one), which I believe were obtained in the neigh- 

 bourhood of Singapore. 



The one is very like TetilJa polyura of 0. Schmidt (' Spongien- 

 fauna des atlantischen Meeres,' t. vi. f. 8), which is the type of my 

 genus LophiureUa, but dift'ers from it in several particulars ; and the 

 other is a form which has not liitherto occurred to me. 



It has been thought that these free sponges are only the young 

 and free state of sponges which become attached in their older state ; 

 but this theory wants further confirmation. TetiUa polyura of 

 Schmidt might be young, as it is only 3 inch long ; but the specimens 

 from Singapore are more than 2 inches in diameter and length. 



The four specimens, which I have caWed Psetalia g/obulosa, exhibit 

 four different states of growth, the sponge being considerably 

 modified in its general form as it enlarges. 



The youngest specimen, about i inch in diameter, is half-oblong, 

 with a few conical projections on the lower part, each ending in a 

 tuft of spicules, and with a flattened upper surface having a small 

 central opening leading to the inner surface. 



In a larger specimen, about Ig inch in diameter, the conical pro- 

 minences on the under surface, each ending in a tuft of elongate 

 spicules, are more numerous, and the upper surface is produced, 

 conical, and ending in a much larger central opening. 



In the largest specimen, about 2| inches in diameter, the sponge 

 is irregularly conical below, the surface being covered with distinct, 

 rather prominent, tubercles, each containing a tuft of elongate 

 filamentous spicules, ending below, as in the other specimens, in 

 three or more recurved anchoring spines. The upper surface is 

 deeply concave, with only a broad convex margin, incurved, edging 

 the concavity. This, like that of the interior of the other specimens, 



