634 MR. J. WOOD-MASON ON THE FAMILY EMBIID^. [DcC. 18, 



mensurately developed veins in the anterior part of each wing is 

 apparently due to a shadow of the radius being cast upon the margin 

 of the brown border of the costa, so as to coincide with the remains 

 of the subcosta ; and Professor Westwood has been the victim of an 

 optical illusion. 



Affinities. — In anticipation of the full and detailed account of the 

 numerous and important differences between them and the Perlida 

 which is in preparation, and will be published as soon as the drawings 

 needed to render my descriptions intelligible are ready, I may say 

 that the Embiidce undoubtedly belong to the true Orthoptera, that 

 they are in my opinion in some respects the lowest term, and in 

 others the lowest term but one, of a series formed by the families 

 Acridioidea, Locustida, GrylUdce, and Phasmatidce, and that their 

 resemblances to the much lower Perlidce, which may well be direct 

 descendants of a form closely related to Campodea, are due to their 

 low position in the division of Orthopterous insects to which they 

 belong, and do not imply any such close genetic relationship to them 

 as has been suggested. 



EXPLANATION OF PLATE LVl. 



Fig. L The right anterior wing of ^a male of Embia (Oliffofoma) saundersii, 



Westwood, X 10. 

 Fig. 1 a. The right posterior wing of tlie same, X 10. 



Figs. 2, 2 a. The same wings with all the details omitted in order that the 

 venation may be seen more distinctly : — 1, 1, the first or costal vein ; 

 2, 2, the second or subcostal vein ; 3, 3, the third or radial vein ; 

 4, 4', 4, the forked fourth or discoidal vein, 4' its rudimentary pos- 

 terior prong; c, the rudimentary first branch; b, the rudimentary 

 second branch ; and a, the termination of its anterior prong (4, 4), which 

 is apically anastomosed to the radius, and conuected with it by five 

 transverse veinlets in the anterior wings and by three in the ]50sterior ; 

 and 5, 5, the rudimentary fifth or anal vein, which is simple and un- 

 branched and connected with the root of the fourth by a transverse 

 veinlet in both the nearly homonomous wings of this insect. 

 (N.B. All the lines in these figures represent -seins, with the exception of thai 

 commencing at a point situated a short distance behind the apex of the anasto- 

 mosed radial and discoidal veins, endiug near the origin of the fifth vein, and 

 representing the posterior margin, in which there is no vein.) 



Figs. 3, 3 «. The same wings with the venation restored by the aid of the brown 

 bands and triple lines of seta : e, the lost posterior, and d, the lost 

 anterior fork of the rudimentary posterior prong of the discoidal vein. 

 (N.B. All the lines in these figures represent veins.) 



Fig. 4. The abdomen of Embia (0.) saundersii J, from above, X 10. 



Fig. 5. The same from below, X 10. 



Fig. 6. Abdomen of Embia (0.) michacli, M'L., § , from below, x3. 



(N.B. The arable numerals in the three preceding figures refer to the somites 

 of the abdomen.) 



