OF ARTS AND SCIENCES. 87 



These strl© were most developed on the face P, and corresponded to 

 the edges of planes of cleavage, which, as is well known, is eminent 

 parallel to o P. One of these angles is almost identical with that 

 given by Breithaiipt. I place, however, no confidence on the accu- 

 racy of the measurement, on account of the imperfection referred to. 

 It is, however, worthy of remark, that the angles of Rose, Breithaupt, 

 and my own, give semiaxes divisible by fourteen, or so slightly dif- 

 fering from a multiple of fourteen, that the difference is fully covered 

 by the possible errors of observation. We might conclude from this 

 that the three observers had measured angles between different planes 

 of the same series, were it not that the ratios between the parameters 

 are so improbable as will appear from the following table : — 



E on i? = 85 4 a = 1.402 nearly 14 X 100 Rose. 



i^ on Ji = 85 26 OT a = 1.388 " 14 x 99 m = -^%% Breithaupt. 



RonR = 85 4l7na=l.S18 Miller. 



Ron R = 85 41 ma= I.S14: " Ux98m=j%% Cooke. 



Dr. Charles Pickering, at the request of Professor Agassiz, 

 exhibited a map illustrating the distribution of quadrupeds 

 over the earth ; and Professor Agassiz exhibited, and com- 

 pared with this, a map which he had just prepared, illustrating 

 the distribution of animals generally. 



On motion of Mr. Tread well, it was 



" Voted, That the second monthly meeting of the present month 

 be passed over, on account of the occurrence of the quarterly meet- 

 ing in this month. 



Three hundred and ninety-third meeting. 



January 25, 1854. — (Quarterly Meeting. 



The President in the chair. 



The Corresponding Secretary read a letter from the Acade- 

 my of Natural Sciences, Philadelphia, acknowledging the re- 

 ception of Vol. V. Part I. of the Memoirs of the Academy. 



Messrs. Treadwell, Emerson, and Eliot were appomted a 

 committee to arrange for a course of lectures before the Low- 

 ell Institute the next season. The course for 1853-4 was 



