April 6, i88S.] 



SCIENTIFIC NEAVS. 



329 



of ^aper^, 3Lectuce^, etc* 



ROYAL SOCIETY. 

 At the meeting on March 22 nd, a paper on the 

 "Skull, Brain, and Auditory Organ of a new species of 

 Pterosaurian [Scaphognathus Purdoni), from the upper 

 Lias, near Whitby, Yorkshire," was read by Mr. E. T. 

 Newton, F.G.S., F.Z.S. 



The specimen described in this paper is the skull of a 

 Pterodactyle, which was obtained from the Upper Lias, 

 near Whitby, and appears to be the first example of 

 these interesting animals found in Yorkshire. It is most 

 nearly related to the form from the Solenhofen Slates, 

 which is known as Pterodadylus {Scaphognathiis) 

 crassirostris, and is to be named after its owner, the 

 Rev. J. W. Purdon, Scaphognathiis Purdoni. 



This fossil skull is about five-and-a-half inches long, 

 but has lost, perhaps, two inches of the front of the 

 snout. The various bones of the skull are better shown 

 than in any Pterosaurian hitherto discovered, notwith- 

 standing that so many examples have been found on the 

 Continent and in this country ; and the back, base, and 

 palatal regions have never before been definitely 

 described. The base is remarkable for its great depth 

 and flattening from before backwards, as well as for the 

 pair of long basi-pterygoid processes, which pass down 

 to the inner angle of the large quadrate. The palatine 

 and pterygoid bones are united into one bar, and 

 anteriorly this forms the hinder boundary of the internal 

 nostril, which is completely surrounded by bone and 

 placed far forwards. The back of the skull exhibits a 

 pair of wing-like par-occipital processes closely resembling 

 those found in some lizards, and, indeed, the structure 

 of the entire skull is most like that of a lizard, although 

 in some points having a very bird-like appearance. 



By carefully cutting away the frontal and parietal 

 regions of the left side, the author has been able to 

 expose a cast of one-half of the brain, which proves to be 

 very small in proportion to the skull, and in this 

 particular, therefore, resembles the brain of a reptile ; 

 but in its structure it shows a greater affinity to the 

 birds. The cerebral lobe is oval in shape, and directly 

 behind it, on the side of the brain, there is a large optic 

 lobe, which although extending to the upper surface does 

 not meet its fellow of the opposite side, as is the case in 

 all reptiles, but seems to have been separated from it by 

 the forward extension of the cerebellum, in a manner 

 similar to that which occurs in birds. The peculiar lobe 

 of nervous matter found at the side of the medulla in 

 birds, and known as the flocculus, is present in this 

 Pterodactyle, but does not occur in reptiles. The 

 American toothed-bird, Hcsperornis, had a brain very 

 closely resembling this Pterodactyle, although propor- 

 tionately larger. 



It is not a little interesting to find that this Yorkshire 

 fossil gives us some information as to the auditory organ 

 of the Pterosauria. In close relation to the flocculus, 

 portions of three semicircular canals have been un- 

 covered which agree so closely in position with the bony 

 semicircular canals of the bird's auditory apparatus, that 

 there can be no doubt as to their having been of a similar 

 nature. The fenestra ovalis has been found similarly 

 placed to that of the chameleon ; and this fact, together 

 with the form and position of the quadrate bone, leads 



the author to conclude that, like the chameleon, this 

 Pterodactyle had no ear drum. 



In considering the relation which the Pterosauria bear 

 to reptiles and birds, it would seem that in the structure 

 of the skull they are related to the Lacertilia, while the 

 form of the brain allies them more closely to the birds. 

 This, however, does not constitute the Pterosaurian a 

 transitional form between birds and reptiles, in the 

 sense of the Pterosauria having been derived from 

 reptiles, or of the birds having been derived from 

 Pterosauria ; but rather points to Avcs, Pterosauria, and 

 Reptilia having been derived from some common 

 ancestral type. 



An interesting paper was read at the meeting on 

 March 22nd, entitled "The Chemical Composition of 

 Pearls," by George Harley, M.D,, F.R.S., and Harald 

 S. Harley. Dr. George Harley began by explaining that 

 during his investigation into the nature and mode of 

 formation of the different kinds of stones'met with in the 

 human body, he had been so struck with the close 

 similarity in appearance of some of them with pearls, 

 that he was led to examine the latter very minutely, and 

 finding that although there are many qualitative analyses 

 of pearls, there is no evidence in their voluminous litera- 

 ture of a quantitative analysis of their ingredients having 

 been recorded, he undertook the examination, of which 

 the following is an account, of several varieties : — 



Of oyster pearls, three varieties were examined — 

 British, Austrahan, and Ceylonese. 



Qualitative analysis showed that they all had an 

 identical composition, and that they consisted solely of 

 water, organic matter, and calcium carbonate. There 

 was a total absence of magnesia and of all the other 

 mineral ingredients of sea-water — from which the inor- 

 ganic parts of pearls must of course be obtained. Seeing 

 that ordinary sea-water contains close upon ten and a 

 half times more calcium sulphate than calcium carbonate, 

 one might have expected that at least some sulphates 

 would have been found along with the carbonates, more 

 especially if pearls are the mere fortuitous concretions 

 some persons imagine them to be. This view the authors 

 could not endorse, from the fact that by steeping pearls 

 in a weak aqueous solution of nitric acid, they were able 

 to completely remove from them all their mineral con- 

 stituents without in any way altering their shape, and 

 but very slightly changing their naked-eye appearances, 

 so long as they are permitted to remain in the solution. 

 When taken out they rapidly dry and shrivel up. No 

 phosphates whatever were found in any of the three 

 before-named varieties of pearls. 



Having ascertained that all three kinds of pearls had 

 exactly the same chemical composition, instead of making 

 separate quantitative analyses of them, as pure white 

 pearls are very expensive, the authors simply selected 

 two pearls from each variety, of as nearly the same size 

 and weight — giving a total of 16 grains — and analysed 

 them collectively, the result obtained being that they 

 consisted of carbonate of lime, 9172 per cent. ; organic 

 matter (animal), 5'94 per cent. ; water, 2-25 per cent. 



A pearl said to be the product of a cocoa-nut was 

 examined by the authors. It had all the external appear- 

 ances of the pearls found in the large clams (Tridacna 

 gigas) of the Southern Ocean, being perfectly globular, 

 with a smooth, glistening, dull white surface, and re- 

 sembling them exactly in microscopic structure. Besides 

 which in chemical composition it bore no similarity to 

 cocoa-nut milk, to which it is supposed to be related. 



