543 PHILOSOPHICAL TRANSACTIONS. [aNNO 1754. 



crust, which was broken off in several pieces. Both these stones were in ap- 

 pearance like a pebble, and formed of different laminae. The greatest circum- 

 ference of the stone taken from this mare was somewhat more than 26 inches ; 

 that of Sir Henry Hickes's 28. 



Sir Henry Hickes's horse was 22 years old ; and, for 11 or 12 years before he 

 died, frequently was observed to be in vio'ent pain ; but the mare, the subject 

 of the present letter, though 1 6 years old, gave no signs of being in pain till 

 about 3 months before her death, when she would frequently lie down, and roll 

 about. And it is the more extraordinary that, large as the stone was, it did not 

 disable the mare from doing her usual work for a more considerable time before 

 her death ; which did not seem to be occasioned by the stone, she dying near 

 her foaling time ; nor so far disturb her economy, as to prevent her propagating 

 her species. 



In 1746, the Duke of Richmond presented to the Society a stone found in 

 the colon of a horse, the circumference of which was 16 inches. His Grace at 

 the same time presented some other stones, found in the intestines of a mare, 

 which were polished like bezoar. It was very remarkable, that 2 of these stones, 

 when sawed asunder, were found to have been formed each on an iron nail, as a 

 nucleus. 



XCFII. On the Belemnites* By Mr. Guslavm Blander, F.R.S. p. 803. 



The belemnites is a fossil, that has hitherto perplexed the naturalists of all 

 countries : it has been treated of by various authors, and differently ascribed to 

 all the 3 kingdoms of nature ; but Mr. B. delivers it as his opinion, that it be- 

 longs to the testaceous part of the animal kingdom, and to the family of the 

 nautili. The nautilus, or sailor, is a concamerated shell, with a syphunculus 

 running through every cell, see pi. 14, fig. 5. The syphunculus, and the 

 concamerations, are the generical character of this tribe, and are supposed to 

 serve the animal to buoy up its shell, by which means it can swim or sink at 

 pleasure. 



Those that are curved are very common, both in the recent and fossil state ; 

 the straight ones have hitherto only been met with fossil, and are common in 

 Sweden, Livonia, and several parts of Germany ; and have, by naturalists, been 

 called orthoceratitae ; and Mr. B had seen some in Dr. Mason's private collec- 

 tion at Cambridge, which he said were found at Whitby in England ; the cha- 



* The belemnites is in all probability a species of nautilus, and its inhabitant may be allied to that 

 of other nautili ; and consequently resemble in some degree a sepia or cuttle, which by the older 

 writers was often called a polypus. Linneus imagined it a petrifaction of the Alcyonium Lyncurium. 

 Mr. Brander's notion of the testaceous tribe in general having proceeded from polypes, can only have 

 Arisen from bis want of zoological information. 



