02 



HARDWICKE'S SCIENCE-GOSSIP. 



access of water to the posterior nostrils and windpipe 

 of the Crocodile : and hence the author is inclined to 

 ascribe a fish-diet even to those massive-jawed Croco- 

 diles from the Purbeck (such as Goniopholis crassidens 

 and simus), which in some respects might seem fitted 

 to grapple with large and active mammals. The 

 small size of the upper temporal apertures in Tertiary 

 and existing Crocodiles is regarded by the author as 

 a further proof in the same direction ; these apertures 

 are reduced by the progressive increase of the osseous 

 roof of the temporal vacuities, which again is corre- 

 lated with increase in the bulk and power of the tem- 

 poral muscles, the main agents in biting and holding. 

 The differences in the length and strength of the jaw, 

 as a rule, testify in the same direction. Further, the 

 fore limbs in Mesozoic Crocodiles are shorter than in 

 Neozoic species, indicating that the former were more 

 strictly aquatic in their habits ; the fore-limbs in all 

 Crocodiles being closely applied to the body during 

 rapid swimming, and small limbs being less ob- 

 structive than larger ones. On the other hand, they 

 would be less efficient as a means of progression on 

 land, and hence it may be inferred that the advent in 

 Tertiary times of mammals frequenting the water-side, 

 tempting the Crocodiles to make a rush upon the land 

 to seize such passing prey, would lead to such 

 strenuous action of the fore-limbs as would account 

 for the increased size and power of those organs in 

 the Neozoic species. The author concluded with 

 some remarks upon the influence of the above con- 

 siderations upon our views as to the generic divisions 

 of Crocodiles. 



The Glacial Period. — Dr. Ricketts, F.G.S., 

 has reprinted his valuable paper, read before the Liver- 

 pool Geological Society, on the "The Conditions 

 existing during the Glacial Period." It also contains 

 an account of the Glacial deposits in the valley between 

 Tranmere and Oxton, near Birkenhead. 



Marine Fossils in the Gannister Beds. — 

 Prof. G. A. Lebour has announced the discovery of 

 marine fossils in the lower coal measures, or " gan- 

 nister" beds of Northumberland, between Stocksfield 

 station and Whittonstall. Hitherto no marine fossils 

 have been met with in these rocks. 



The Geology of Colorado. — The Atlas of 

 Colorado, soon to be issued by the United States 

 Geological Survey of the Territories, under Prof. 

 F. V. Hayden, embodies the results of the geological 

 and geographical work of the survey during the years 

 from 1873 to 1S76 inclusive. This Atlas will contain 

 the following maps : — 1st, A general drainage map of 

 Colorado, on a scale of twelve miles to the inch. 

 2nd, An economic map of the same region, having at 

 its basis the above-mentioned drainage map. This 

 map will indicate the areas of arable, pasture, timber, 

 coal, mineral, and desert land in as great detail as 



possible on the scale. 3rd, A general geological map 

 on which the areas covered by the principal forma- 

 tions will be shown. The drainage map will form 

 the basis for this also. 4th, A map showing the 

 scheme of the primary triangulation in the State. 

 Scale, twelve miles to the inch. 5th, Six topogra- 

 phical sheets, showing the same area as that covered 

 by the general drainage map, but in much more detail. 

 The scale of these sheets is four miles to an inch. 

 The relief of the country is indicated by contour lines, 

 at vertical intervals of 200 feet. The area covered 

 by each of these sheets is 11,500 square miles. 6th, 

 Six geological sheets, of which the basis is the six 

 topographical sheets just mentioned. On these the 

 detailed geology is expressed by colours. With the 

 appearance of this map, Colorado will be better 

 known, topographically and geologically, than any 

 other State. 



Winds, Ocean-Currents, and Tides. — Mr. 

 W. L. Leighton, F. R. G. S., has published a second 

 edition of his lecture on the above subject, together 

 with the discussion which arose when the discourse 

 was delivered. Mr. Leighton is a formidable antago- 

 nist, and is not likely to surrender his own views 

 because some scientific authorities think lightly of 

 them. Even the latter must confess that he makes 

 out a good case. 



Fossil Fungus. — Prof. Lesquereux has recently 

 described a fossil fungus (RhizomorpAw sigillaritz) 

 discovered under the baric of a Sigillaria from the 

 Carmelton Coal of Beaver County, Pennsylvania. 



NOTES AND QUERIES. 



A Singular Place for a Bird's-nest. — 

 Whilst waiting on the platform of the railway-station 

 at Coventry, one day last week, I observed an old 

 sparrow's nest built inside a signal-bell. This bell is 

 of a saucer shape, some 10 inches in diameter, and 

 placed with its concave face within about ii inch 

 of the side of the "crossover" bridge, and directly 

 over the centre of the railway. The hammer-head 

 of this bell is attached to a long lever, in connection 

 with a wire, leading to a distant operating spot. 

 There is also a heavy counterweight and lever, 

 forming part of the apparatus of the signal ; so that 

 when the bell is struck, there is, besides the loud 

 ringing, a great rattle and noise of levers, and a 

 heavy thump caused by the falling counterweight. 

 This bell is used many times every hour of the day, 

 and frequently during the night, three or four blows 

 being struck each time. The officials of the station 

 informed me that inside the bell was a favourite 

 building place of the sparrows, and that the nests had 

 frequently to be removed, but that young ones had 

 been hatched and reared there. — ' G. A. Biddell, 

 Ipswich. 



Carnivorous Slug. — Whilst perusing the 

 columns of your journal, the accounts of the predatory 

 slug recalled to my memory a circumstance which 

 occurred to me some years ago. While out walking 



