G. H. F. Nuttall 
203 
extremes I have figured can be observed. As we look down the series 
the scutal punctations grow less marked, the adanal spines gradually 
dwindle and disappear, the anal plates grow rounded posteriorly and 
become less and less prominent, the caudal protrusion in replete males 
dwindles, the protarsus appears less and less swollen, etc., etc. Therefore, 
the determination of specimens possessing intermediate characters will 
only be possible when they can be compared to members of an authentic 
series like the one which we have raised experimentally from a single 
parent. 
In the following paper by Mr Norman Cunliffe the variability of 
R. pulchellus in size, structure and ornamentation forms the subject of 
a careful study which I requested him to undertake upon this well 
defined species. Mr Cunliffe’s results confirm mine in all essential 
particulars. 
14—2 
