Intelligence and Miscellaneous Articles. 15S 



Melania quadrilineata, /. Sby. ; M. Hunteri ; Paludina norraalis ; P. Decca- 

 nensis, /. Sby. ; P. Wapsharei ; P. acicularis ; P. pyramis ; P. subcylindracea ; 

 P. Sankeyi ; P. Takliensis ; P. soluta ; P. conoidea ; P. Rawesi ; P. Virapai ; 

 Valvata minima ; V. unicarinifera ; V. multicarinata ; V. decollata ; Succinea Nag- 

 pureusis ; Liraiia;a oviformis ; L. subfusiformis ; L. attenuata ; L. peracimiinata ; 

 L. Spina ; Pliysa Prinsepii, /. Sby., var. elongata, var. inflata ; Ph. Bradleyi ; 

 Unio Malcolmsoni ; U. Hunteri ; U. cardioides ; U. mammillatus ; U. imbricatus ; 

 U. Carteri. 



Shells from the estuary strata near Rajamandri (all new spe- 

 cies) : — 



Pseudoliva elegans ; Natica Stoddardi ; Cerithium multiforme ; C. subcylin- 

 draceum ; C. Leithi ; C. Stoddardi ; Vicarya fiisiformis ; Turritella pra;longa ; 

 Uydrobia Ellioti ; Hemitoma ? multiradiata • Ostrea Pangadiensis ; Anomia Kate- 

 ruensis; A. modiola ; Perna meleagriiioides ; Modiola, sp. ; Corbis elliptica ; Cor- 

 bicula ingens ; Cardita variabilis ; Cytherea orbicularis ; C. Wilsoni ; C. Wap- 

 sharei ; C. Rawesi; C. Jerdoni; C. elliptica; C. Hunteri ; Tellina Woodwardi ; 

 Psammobia Jonesi ; Corbula Oldhami ; C. sulcifera. 



Fossil Insects from the Tertiary strata near Nagpur : — 



Lomatus Hislopi, sp. nov. ; and three other Buprestida (indefinable). Meristos 

 Hunteri, nov. ; and seven other CurcuUonidce (indefinable). 



XXVI. Intelligence and Miscellaneous Articles. 



ON THE EXPANSION OF CRYSTALLINE BODIES BY HEAT. 

 BY H. HAHN. 

 It is a law long since discovered by Mitscherlich, that crystalline 

 -■- bodies expand equally in the direction of their similar axes] but un- 

 equally in the direction of their dissimilar axes. According to this 

 law, only those bodies that belong to the regular system expand 

 equally in all directions, while those that belong to the quadratic 

 and hexagonal systems present two axes, and those belonging to the 

 other systems three axes of unequal expansion. The greatest expan- 

 sion is not, however, as might have been expected, in the direction 

 of the principal axis (calc-spar, bitter-spar), but sometimes in the 

 direction of the other axes (quartz). The author gives a calculation 

 of the expansion of certain crystals in the direction of their different 

 axes. 



Calc-spar (hexagonal system). — According to Mitscherlich, the 

 terminal dihedral angle of the primary rhomboid becomes 8' 34"-5 

 more acute, on its temperature being raised to 100° C. At the mean 

 temperature 14° R. (= 17°-5 C.) it measured 105° 5'; at 100° C. 

 it is therefore 104° 56' 25"-5. Calculated from the first of these 

 angles, the proportion of the axes is as follows : — 



a:c=11706: 1 = 1 : 08543; 

 from the second, 



«:c=l-lG50: 1 = 1 : 0-8584. 

 The expansion of axis a up to 100° being taken as unity, axis cthen 

 increases 1 -00479 times as much as a, or for one degree -0121792 

 times as much. The cubical cx])ansion is three times the linear; if, 

 then,.vbu the expansion in the direction of the axiy of «, that in the 

 direction of the axis c will be xx 1 00479, and the cubical expan- 

 sion will be XX 3-00479. Kopp found that the cubical expansion 



