378 MH. K. m'lachlan on the 



In G-erstacker's system Termes precedes Blatta, and is sepa- 

 rated from Embia by the whole of the true Orthoptera. This is 

 a radical change ; but I am disposed to agree with this author in 

 considering Termes more nearly related to Blatta than the former 

 is to Embia. 



"With regard to the sexual differences in the Embidee, West- 

 wood, forty years ago, remarked, " sexus differentia Latet." This 

 obtains almost equally now ; and I am not able to throw much 

 light upon the subject. M. Lucas dissected several examples of his 

 E. mauritanica', and all were apparently females. He speaks 

 (Expl. d' Algerie) of asymmetry in the caudal processes iu all the 

 examples examined, the basal joint of the left process being much 

 broader and more flattened than the right, and asks if this be a 

 sexual character. I think not, and beheve the asymmetry is 

 almost (if not quite) universal in the family. All species exa- 

 mined by me possess it in a more or less marked degree. In some 

 examples there is a slender spiniform process between these arti- 

 culated side processes ; but the materials at hand are too limited 

 to enable me to decide if it represents the intromittent organ, or 

 is common to both sexes *. 



Eespecting the genera of Embidse, Westwood (as before stated) 

 divided Embia into two sections and three subgenera, of which I 

 reproduce the diagnoses : — 



Sectio 1. Palpi maxillares 5-articulati. Antennae thoraceljre- 

 viores, articulis subtus 20. 

 Subgenu^s 1. Antennae 15-articulatae ; alse nervo 3tio interno 



cum 4to nervis transversis connexo, hoc trifido. Embia, 



Eat. 

 Subgenus 2. Antennae 11-articulatae, articulo ultimo apice 



submammillato ; alse nervo 3tio interno cum 4to 'nervis 



transversis baud connexo, hoc bifido. OiiaoTOMA, W. 

 Sectio 2 (subgenus 3) . Palpi maxillares 4-articulati. Antennae 

 corporis fere longitudine, articulis 32. Alae nervo 4to interno 

 trifido. Oltntha, Crrai/. 



For my part I am disposed to consider the genera Embia and 

 Olyntha identical, at any rate on the characters above given ; for 

 the maxillary palpi of Olyntha are 5- (not 4-) jointed (I have exa- 



* In Oligotoma Satmdersii this spiniform process has a small tooth before 

 the apex on its lower side. I do not see the process in all the examples ; hence 

 it may perhaps be sexual, and possibly is the intromittent organ. 



