of a StrUlidatiiKj Appdrdtus in certain Mantidce. 263 



2. On the presence of a Stridnlating Apparatus in certain 

 Mantidaj. [Head October 2nd, 1878.] 



In the Mantidce, as in all other orthopterous insects, a 

 stout, stiff, hard, and tubular longitudinal ridge-like 

 thickening, termed the principal nervui'e (Ji), divides the 

 tegmina into two unequal portions, which, supposing the 

 Avings to be extended at right angles to the body, as in 

 flight, may respectively be described as anterior and 

 posterior. 



The smaller anterior portion, technically called the 

 marginal field (m), is bounded in front by another stiff, 

 hollow thickening — the so-called marginal nervure {ni), 

 constituting the anterior boundary of the organ, and, when 

 viewed from above, usually appearing to be more or less 

 distinctly bevelled in fi'ont. On closer inspection, how- 

 ever, this apparently-bevelled edge is seen to be a thin, 

 narrow, and deflexed lamellar expansion (m') of the 

 nervure. 



Fiff. 1. 



Fig. 1. Hierochtla simulacrum, J- The left tegmen, 7), /;, the principal 

 nervure dividing the organ into a larger posterior portion, made 

 up of a discoidal (D) and an anal (A) area, and into a smaller 

 anterior portion, the marginal field (M) ; m, m, the marginal 

 nervure ; ni', m', its lamellar expansion. 



In such a species as Hierodula. simnlacrum, Avhen the 

 wings are fully extended, the marginal field of the teg- 

 mina slopes downwards and forwards so as to form with 

 the posterior portion (d + a) of those organs an angle of 

 about 1.30°; but when they are firmly closed, the former 

 is then bent down almost at right angles to the latter, 

 and the consequence is that the lamellar expansion of 



