164 Miscellaneous. 



moir, being the most numerous of all the families of Echinites, and 

 at the same time the earliest form under which shells of this kind 

 appear to have existed ; they are the only family that occurs so 

 early as the muschelkalk, whilst no other family of Echini is found in 

 formations older than the Jurassic, in which the Cidarides are most 

 numerous; they abound also in the cretaceous and tertiary formations, 

 and in our actual seas*. In the Jura mountains they are most nu- 

 merous in a stratum, called Terrain a Chailles, abounding, with 

 other littoral shells, near the middle region of the oolite formation. 



Professor Agassiz has also published the first monograph of an- 

 other splendid work, ' Monogi'aphies d'Echinodermes, vivans et fos- 

 siles,'-j- which will be extended to ten or twelve parts, to be completed 

 in three or four years, and will contain about 150 plates, some of 

 them coloured, from careful drawings of this most beautiful class 

 of shells. Collections of casts of all the fossil species of this class 

 known to M. Agassiz may be obtained by purchase, or in exchange 

 for objects of natural history, at the Museum of Neufchatel. 



In the family of Star-fish two new fossil genera have been recently 

 established by Mr. Gray t, one of these, Comptonia, founded on a 

 specimen from the whetstone pits in the greensand of Blackdown, 

 Devon, recently acquired by the Marquis of Northampton ; it is 

 preserved in the state of beautiful chalcedony, and explains the in- 

 termediate character of the genus Ccelaster of Agassiz. The other 

 new genus Fromia, comprehends the curious tesselated star-fishes 

 found in the chalk, and also a recent species found in various parts 

 of New Holland. 



Professor Agassiz will shortly send an artist to England, to figure 

 for his great work on living and fossil Echinoderms, the individual 

 specimens which Mr.jGray has described in his Monograph on Star- 

 fish. It is a new and important feature in the progress of zoology 

 and palaeontology, that this much-neglected department of radiated 

 animals is at length receiving that attention which, from the time of 

 Henry Linck, who dedicated a large volume on this subject to Sir 

 Hans Sloane (1733), to the moment when it has recently been re- 

 sumed by Nardo, Agassiz, and Gray, it has so long merited in vain. 

 [To these must now be added the elegant and highly interesting Hi- 

 story of Star-fishes and Echinodermata by Mr. Edward Forbes, — a 

 work full of entertainment for the general reader, as well as of accu- 

 rate and original information for the scientific naturalist. — Ed.J 



SPONGES IN CHALK FLINTS. 



Mr. Bowerbank, in a paper on siliceous bodies in the chalk, green- 

 sand, and Portland oolite, has applied the evidence of microscopic 

 observation to confirm the opinion long entertained by many natu- 



* Cidarides have recently been found in the carboniferous limestone of 

 the Mendip Hills, near Fronie, by Miss Bennet, and by myself in the car- 

 boniferous limestone near Donegal, in 1811. 



t We have received from Mr. Charlesworth a translation from the second 

 number of this work of " Observations on the progress made in the History 

 of the Echinodermata," which will appear in our next. — Ed. 



I See Monograph on Star-fish, Ann. Nat. Hist., No. 36, Nov. 1840, 

 vol.vi. p. 175,278, 286. 



