VOL. XLVI.] PHILOSOPHICAL TRANSACTIONS. ' 10^ 



immediately : after which she could never make water, unless the stone was first 

 moved, and she continued in great agonies till she died. This monstrous stone 

 weighs 33 oz. 3 drs. 36 grs. Troy. There appears to have been at least -J- oz. 

 broken off, to examine its internal structure ; not to mention what it must have 

 lost by mere wear in 80 years. 



We are told, that they have in the hospitals of Paris, human calculi weighing 

 34 Paris oz. but this in Trinity library, even at present, weighs 34 Paris oz. 

 wanting Q grs. and must have weighed considerably more when it was whole. 

 Yet these are perhaps the heaviest that are any where recorded ; except that very 

 extraordinary one mentioned by Dr. Lister, in his journey to Paris, p. 232 ; 

 which he says was taken from a monk, a. d. 169O, and weighs 51 oz. 



This history may confirm to us the usefulness of endeavouring to relieve the 

 violence of pain in this distemper, by altering the position of the stone in the 

 bladder, either with the help of the catheter, or by some proper alteration in the 

 posture of the patient ; since, with respect to the pain which it occasions, the 

 situation of the stone appears to be of far more consequence than its size. 



0/ a Nondescript Petrified Insect.* By the Ren. Charles Lyttelton, LL. D. and 

 F. R. S., Dean of Exeter. N" 496, p. 598. 



The curious fossil now exhibited to the society is as rare as its figure is elegant ; 

 having never been mentioned by any of our own writers who treat on fossils, and 

 but very imperfectly described by foreign lithographists. Dr. L. discovered a 

 single specimen of it fig. 9, 10, 11, pi. 1, last year, in the limestone pits at 

 Dudley in Worcestershire; and very lately a large mass of limestone (plate 2,) 

 full of them in the same place ; both which are now submitted to the inspection 

 of this learned body, who are best able to determine to what class of the animal 

 kingdom it properly belongs. 



Addenda to the preceding paper. Extract of a letter from the Rev. Dr. Lyt- 

 telton to C. Mortimer, Sec. R. S. — ^The Rev. Dr. Shaw, of Oxford, has pro- 

 cured a specimen of the extended eruca. As the fossilists differed in their opinion 

 of this Dudley fossil, some pronouncing it an eruca, others a bivalve, he thought 

 it best to leave the reader to judge for himself from the engravings ; but, as 

 we are now able to add a specimen of this fossil in an extended position, there is 

 a better pretence to call it an eruca. See fig. 12, 13, 14, pi. 1. 



* The aniinal itself is as yet undiscovered in its recent state. It seems to be a species either of 

 Oniscus or Monoculus. The fossil is the EntomoUtkus paradoxus of Linnaeus. 



VOL. X. 



