120 BULLETIN OF THE 



CENTETOIDA. 



9. Centetidre = Centetinae. 



10. Oryzoryctidse = Oryzoryctina?, Dobson, Mori. Insect., pp. 2, 

 71. 1882. 



11. Solenodontidre, Dobson, Mon. Insect., pp. 3, 87. 1882. 



12. Potatnogalidse. 



13. Geogalidae = Geogalinre, Dobson, Mon. Insect., p. 2. 1882. 



CHRYSOCHLOEOIDEA. 



14. Chrysochloridse. 



The " Monograph of the Insectivora," by Surgeon-Major Dob- 

 son, will fill a long-felt want, and exceptionally well represent the 

 present condition of our knowledge respecting the existing repre- 

 sentatives of the order. 



223d Meeting. November 4, 1882. 



The President in the Chair. 

 Forty-five members present. 



The minutes of the last meeting were read and approved. 

 A communication was made by Mr. G. K. Gilbert: 



ON A GRAPHIC TABLE FOR COMPUTATION. 



[Abstract.] 



On Nov. 17th, 1881, a new method of barometric hypsometry 

 was presented to the Society, and this has since been published in 

 the Second Annual Report of the Geological Survey. It involves 

 a new formula. In the application of that formula an approximate 

 value of the required altitude is first obtained, to which a correc- 

 tion is then added. For the determination of this correction a 

 table was prepared, to be entered with two arguments. Although 

 this table was spread out on six octavo pages, and although the de- 

 duced correction is small, it was nevertheless found impracticable 

 to avoid a double interpolation. To escape this inconvenience the 

 graphic table was afterwards devised. 



The graphic table consists of three super-imposed sets of lines. 

 In each of two sets the lines are straight, parallel, and equidistant, 

 and those of one set intersect those of the other at right angles. 



