Contents of Volume XIII. 
67 
Note on the sums of two series ....... 
Messenger of Mathematics, t. xix (1890), pp. 29—31 
On the focáis of a quach'ic surface ...... 
Messenger of Mathematics, t. xix (1890), pp. 113—117 
On Latin squares ......... 
Messenger of Mathematics, t. xix (1890), pp. 135—137 
Note on reciprocal lines ........ 
Messenger of Mathematics, t. xix (1890), pp. 174, 175 
On the equation xF‘ —1 = 0. 
Messenger of Mathematics, t. xix (1890), pp. 184—188 
Note on Schlaeflis modular equation for the cubic transform 
ation ; ivith a correction ....... 
Messenger of Mathematics, t. xx (1891), pp. 59, 60; 120 
Note on the ninth roots of unity ...... 
Messenger of Mathematics, t. xx (1891), p. 63 
On two invariants of a quadri-quadric function 
Messenger of Mathematics, t. xx (1891), pp. 68, 69 
On a particulam case of Rummer’s differential equation of 
the third order ......... 
Messenger of Mathematics, t. xx (1891), pp. 75—79 
Note on the involutant of two matrices ..... 
Messenger of Mathematics, t. xx (1891), pp. 136, 137 
On an algebraical identity relating to the six coordinates of 
a line ........... 
Messenger of Mathematics, t. xx (1891), pp. 138—140 
On the notion of a plane curve of a given order . 
Messenger of Mathematics, t. xx (1891), pp. 148—150 
On the epitrochoid ......... 
Messenger of Mathematics, t. xx (1891), pp. 150—158 
On a soluble quintic equation ....... 
American Journal of Mathematics, t. xm (1891), pp. 53—58 
On the partitions of a polygon ...... 
Proc. Lond. Math. Soc., t. xxii (1891), pp. 237—262 
\_Note on a theorem in matrices] ...... 
Proc. Lond. Math. Soc., t. xxii (1891), p. 458 
[Note on the theory of rational transformation] 
Proc. Lond. Math. Soc., t. xxii (1891), pp. 475, 476 
9—2