HARDWICKE'S SCIENCE-GOSSIP. 



279 



GEOLOGY. 



Sargodon Tomicus. — We have received some 

 beautiful sections of the teeth of this fossil fish from 

 Air. Thomas D. Russell, 48 Essex Street, Strand. The 

 fossil teeth from which these interesting sections are 

 made are obtained from a bone breccia or con- 

 glomerate in a group of rocks known as the Penarth 

 Beds, a term employed by the English Geological 

 Survey to designate the passage beds that lie between 

 the Trias and Lias, from their typical development at 

 Penarth in Glamorganshire ; the series are also 

 known as the Rhaetic beds, St. Cassian beds, and Zone 

 of Avicula contorta. These strata are but sparingly 

 represented in Great Britain, in the typical district 

 the entire thickness is one hundred feet, whereas in 

 the Rhaetian Alps bounding the northern plain of 

 Lombardy they attain a thickness of over three 

 thousand feet. The breccia or conglomerate is of 

 inconsiderable thickness, rarely exceeding one inch. 

 It consists of pebbles and subangular fragments of 

 quartz, and is exceedingly rich in disintegrated fish 

 remains. The forms in which the teeth of this 

 genus occur are so varied that it is not surprising that 

 they were originally considered to have belonged to 

 distinct families, and it was not until a comparatively 

 recent date they were supposed to belong to one 

 species only ; the microscope has however satis- 

 factorily decided the question, definitive identity of 

 structure being exhibited notwithstanding the diver- 

 sity of external forms. The teeth originally known 

 as Sargodon Tomicus may be described as chisel or 

 wedge-shaped, while associated with them were 

 other forms which were referred to the genus 

 Sphrerodus ; an examination of a large number dis- 

 closed the fact that by almost imperceptible grada- 

 tions they passed from the original known form to 

 bulbous, hemispherical, and subangular, while the 

 proportion they bore to each other appeared to 

 elucidate the obscurity thus apparently set up. The 

 inference is that the chisel-shaped teeth occupied the 

 fore part of the mouth and were used for cropping the 

 algae on which it is supposed the creature fed, while 

 the other forms covered the interior of the mouth 

 like an enamelled pavement, and were employed in 

 crushing the food ; at the present time there exists a 

 fish in the rivers of British Guiana possessing similar 

 characteristics. It is impossible to convey an adequate 

 idea of the beautiful structure of the fossil teeth ; 

 they must be seen to do justice to them. They 

 possess the advantage of being equally good objects 

 with ordinary or polarised light ; when the latter 

 means of illumination is adopted, the large quantity 

 of ganoine or transparent enamel produces a most 

 pleasing effect ; while with the former means the 

 calcigerous tubules forming the centre and ramifying 

 towards the exterior of the tooth are exceedingly 

 interesting. 



Notes on Scottish Carboniferous Microzoa 

 and the methods by which they may be collected 

 and mounted. — Mr. John Young, F.G. S., has con- 

 tributed a capital paper on this subject to the 

 Edinburgh Geological Society, which cannot fail to 

 lead microscopists to investigate the almost unknown 

 field of the Carboniferous microzoa, to be obtained 

 from the soft, weathered, fossiliferous shales which 

 alternate with the Limestone strata. 



Fossil Snakes. — Dr. Sauvage is said to have 

 discovered the remains of a reptile allied to serpents 

 in the upper Greensand formation of Charente. 

 Hitherto fossil serpents have not been met with in 

 strata older than the Eocene. The above reptile is 

 stated to be quite a new form. 



NOTES AND QUERIES. 



ComMensalism.— On the 3rd of September last, 

 while sitting in a field at Wick, near Christchurch, 

 Hants, I observed a water-wagtail following the 

 nose of a grazing pony most closely, nothing daunted 

 by its munching and moving ; the farmer with whom 

 I was in company remarked he had often noticed 

 the same thing, but had never discovered the reason 

 why. In a few moments we both saw the bird fly up, 

 and unmistakably help himself to a fly from the 

 pony's forehead. This action was repeated, and we 

 afterwards saw the water-wagtail following the snout 

 of pigs, with evidently the same design. Such mutual 

 accommodation was very pleasant to witness. — A. B. 



Sphinx Ligustri. — I can say in answer to 

 G. W. C.'s question on p. 236, that I have a Sphinx 

 Ligustri whicii was in the pupal state for two winters : 

 it is much smaller than usual, viz. 3$" only from tip 

 to tip of wings and a very pale colour, otherwise 

 as other specimens. — Henry JVard. 



Can a Parrot reason ? — From observations of 

 mine, a grey, brought to me by a friend, young, from 

 West Coast, Africa, I should certainly say, yes, to a 

 small extent. A favourite expression of mine is, 

 " Ask for it," but it does not utter the words till it 

 sees food on the table. It may be in the room all 

 day, see the table cloth spread, but until we sit down 

 to eat, Polly is quiet, and then the bird will " Ask 

 for it!" "Ask for it!" until it gets something. 

 The most curious coincidency of speech at least 

 sometimes occur. A medical gentleman and myself 

 were looking at and talking about some geological 

 specimens, when Polly, previously silent, called out 

 " That's a beauty ! " The Dr. remarked, " Why that 

 bird seems to know what it says." Another day a 

 friend was deploring the revelations connected with a 

 recent divorce case when Polly exclaimed " Shocking, 

 shocking, that's shocking ! " In both of these cases 

 I cannot but think that though Polly did not under- 

 stand what was being said, yet it did appreciate some- 

 thing in the tone and manner of the speakers with 

 " beauty " and "shocking." If it bears us call our 

 servant, Kate ! Kate ! the parrot will almost invariably 

 call out "Yes, sir!" mentally associating the girl's 

 name which it does not repeat, with her reply, v. ich 

 it imitates in "yes, sir!" as it never utters those 

 words unless in association with her name. Once 

 while a number of friends were singing grace before 



