630 PHILOSOPHICAL TRANSACTIONS. [aNNO 1733. 



cavity. Of these last stones, he produces g different species, which he distin- 

 guishes chiefly by the pipe, or canal, which runs through them. 



In his note concerning the belemnites prusscici, of which he describes two 

 species, he remarks that the stony cone, or nucleus of it, is never found arti- 

 culate, as in those that come from Sweden, and some other countries. 



At the latter end of his book he proposes a methodical distribution of the 

 Echini and Echinites, or stones that are generated under ground in the cavities 

 of the Echini. 



The whole method he proposes for ranging shells in general, may be seen in 

 the following Table. 



Tabula Metliodica Testaceoruvi. 



TESTA — 'Culmlosa — Monothalamia — Tubulus, Dentalia, entalia, solen-univalvis, — unde 



belemnites pruss. 

 Cochlidium, Nautilus tenuis, auris marina, nerita, 

 cochlea, buccinum, murex, cassis, ey- 

 lindrum, voluta, porcellana. 

 PoLYTHALAMiA — Polythalamium, Nautilus, ammonia, lituus, orthoce- 

 rata. 



ilasnilosa — Simplex Lcpas, Patella. 



Concha, Chama, mytulus, tellen, pinna, ostrea, pec- 

 ten, anomia- 



CoMPOsiTA Conchoides, Pholas, concha anatifera. 



Balanus, Balanus. 

 . ,: , I Echinus, Echinometra, echinoconus, echinocorys, 



echinanthos, echinospatagus, echinobris- 

 sus, echinodiscus. 



yin Account of a Booh entitled, Osteographia, or, the Anatomy of the Bones. 

 By IFm. Cheselden, F.R.S. By John Belchier, F.R.S. N°430, p. 194. 



Of this work mention has been before made in the biographical account of 

 the author, at p. 672, vol. 5, of these Abridgments. In delineating the bones, 

 Mr. Cheselden made use of a Camera Obscura, somewhat different in its con- 

 struction from that in common use, and of which he gives a description. By 

 this he informs us, he was not only enabled to give the true proportions and 

 outlines of the bones, but by the help thereof to do more in 1 day than could 

 possibly be done without it in several days. 



