927 



the Royal Society's Apartments is satisfactorily proved, and that the 

 same cause has been in operation at both seasons; this cause he 

 considers to be the vicinity of the river Thames to the place of ob- 

 servation. With the view of showing the extent to which this cause 

 operates, a table is given of the njean monthly temperature of the 

 water of the Thames, and a comparison is made between the results 

 of observations made on board the ' Dreadnought " Hospital Ship, at 

 the height of 32 feet above the water, with simultaneous observa- 

 tions at the Royal Observatory. From this comparison it is con- 

 cluded, that at all seasons of the year the temperature at the ' Dread- 

 nought' is above that at the Ol3servatory during the night hours, 

 and that it is below during the mid-day hours only : at times of ex- 

 treme temperature the effects of the water upon the temperature of 

 the air is very great. 



The paper is accompanied by diagrams exhibiting to the eye, by 

 means of coordinates, the numerical results given in the tables. 



2. " On the Communications between the Tympanum and Palate 

 in the Crocodilian Reptiles." By Richard Owen, Esq., F.R.S. &c. 



After citing the descriptions by Cuvier, Kaup, Bronn, and De 

 Blainville of the Eustachian tubes and the foramina in the base of 

 the cranium of the recent and extinct Crocodiles, the author gives an 

 account of the nerves, arteries, veins and air-tubes that traverse these 

 different foramina, and thus determines the true position of the ca- 

 rotid foramina and posterior nostrils in the Teleosauri and other 

 fossil Crocodilia, which had been a matter of controversy amongst 

 the authors cited. In the course of these researches the author dis- 

 covered a distinct system of Eustachian canals superadded to the or- 

 dinary lateral Eustachian tubes, which he describes as follows: — 



"From each tympanic cavity two passages are continued down- 

 wards, one expands and unites with its fellow from the opposite side 

 to form a median canal which passes from the basisphenoid to the 

 suture between thai and the basioccTpital, where it terminates in the 

 median canal continued to the orifice described by M. De Blainville 

 as the posterior nostril. ' The second passage leads from the floor of 

 the tympanic cavity to a short canal which bends towards its fellow, 

 expands into a sinus and divides : one branch descends and termi- 

 nates in the small lateral foramen at the lower end of the suture be- 

 tween the basioccipital and the basisphenoid : the other branch 

 continues the course inwards and downwards until it meets its fellow 

 at the median line of the basioccipital, and it forms the posterior 

 primary division of the common median canal : this soon joins the 

 anterior division, and the common canal terminates at the median 

 opening below. Membranous tubes are continued from the three 

 osseous ones, and converge to terminate finally in the single Eusta- 

 chian orifice on the soft palate behind the posterior nostril. The 

 mucous membrane of the palate lines the various osseous canals 

 above described, and is continued by them into the lining membrane 

 of the tympanum." 



With regard to the homologies of the above described air-passages, 



