364 Mr. A. Henfrey on the Development of Vegetable Cells. 



amount of constriction. The general outline of the muzzle, 

 instead of being acute and subcuneiform, is obtuse and oblong, 

 somewhat resembling the form of C. palustris of the Ganges. 

 There is also a marked constriction behind the twelfth tooth, con- 

 siderably greater than in C. vulgaris. The largest teeth are the 

 third, the fourth, and the tenth, the last being the largest of all. 

 The nasal aperture is more circular than in C. vulgaris. There is 

 no lower jaw to the Belfast specimen. Plate VII. figs. 1, 2 and 

 3 represent the cranium, viewed from the top, side and palate, 

 as in C. cataphractus. 



The dimensions of the cranium are as follow : — 



C. cataphractus. C. marginatus. 



Dimensions. inches. inches. 



Length of cranium from the point of the muzzle V . _ - ,„ 



to the occipital ridge f 



Length of cranium from the point of the muzzle V . 7 . _ 



measured to the condyle of the upper jaw J 



Extreme width of cranium at the condyles 7 8*5 



Length from occipital ridge to base of nasals 6 67 



Length from the point of the muzzle to base of "I „ -_ 7 



nasals J 



Length of orbit 1-8 2-7 



Width of orbit 1-4 2 



Interval between orbits *8 1*5 



Antero-posterior diameter of crotaphite foramen ... 1*1 1*9 



Transverse diameter of crotaphite foramen -8 1*4 



Width of the muzzle at the last tooth 6*7 



Width of the muzzle at base of the nasals 2*8 6*5 



Width at contraction behind the twelfth tooth 4-8 



Width at the tenth tooth 6-8 



Width at the ninth tooth 2 



Width at contraction behind the fourth tooth VI 



Greatest contraction behind fifth tooth 2*9 



Dilatation of the point of the muzzle 18 4-3 



Length of the nasal aperture *9 2 



Width of the nasal aperture -75 1*8 



Length of intermaxillaries on the palate 3 3*9 



Length of maxillaries on the palate 6-3 4*1 



Antero-posterior diameter of palatine foramen 4*7 



Transverse diameter of palatine foramen 1*9 



XXXIX. — On the Development of Vegetable Cells. 

 By Arthur Henfrey, F.L.S. * fc 



[With a Plate.] 



In some observations which I had the honour to lay before this 

 Section at Cambridge last year, I brought forward certain views I 

 had adopted in regard to the multiplication of vegetable cells by 

 division, which I then stated to be to a certain extent hypothetical, 



* Read before the British Association, Southampton, Sept. 1816, and 

 communicated by the Author. 



