474 M. straus-durckheim's 



last is articulated to the anterior apophysis of the sterman of 

 the prothorax '' {corselet). 



These parts, which always are two in number on each side, 

 in the Coleoptera, are the last i-emains of two segments, which 

 have disappeared between the head and prothorax (corselet). 



In Forjicula they form two small rings surrounding the neck. 

 They are also very distinct in Blatta and the Orthoptera. 



M. Straus-Diirckheim, without assigning any reason for the 

 change, has altered the names usually given to the three seg- 

 ments, included by Kirby under the general name of tr uncus; 

 calling the jjrothorax the corselet, the two remaining ones, 

 when taken together, the thorax; and, when separately, the 

 prothorax and metathorax. But, in order to avoid confusion, 

 I shall uniformly adhere to the received terms ; because, I 

 conceive, a name once given, ought only to be changed on the 

 ground of its being inapplicable.*^ 



The whole upper part of the prothorax is occupied by a 

 large convex plate, {le boucUer), which curves laterally, and 

 inwards, until it meets the prosteriinm. The anterior part of 

 the lateral margin unites with the alee of the prosternum ; 

 and, posteriorly, the same margin is prolonged into a strong 

 apophysis, {apophyse scuto-sternale,) which unites with the 

 prosternum : between this apophysis and the al<x of the pro- 

 sternum is a large opening, in which is placed the leg. The 

 prosternum {sternum anterieur) occupies the lower part of the 

 prothorax ; it presents a central part and two pairs of lateral 

 apophyses ; one of which, the alee of the prosternum, forms 

 part of the external envelope of the prothorax, uniting the 

 prosternum by its anterior part to the boucUer. From the 

 union of these, and that of the scuto-sternal apophyses with 

 the prosternum, arises the apertures mentioned above. The 

 lateral margins of the prosternum are prolonged into these 



■i Not of M. Straus; his prothorax is what is commonly called the mesoihorax. 

 —Ed. 



» It is much to be regretted that so able an author should, by substituting new 

 names for those previously given, without any reference to the former ones, have 

 induced so much confusion that even that great entomologist, whose death we 

 have lately had to deplore, was compelled to own that he could not unravel it. 1 

 trust that should I (who even amongst the least of your correspondents may be 

 said merely argufos infer streperc anser olores) fail in making myself so clearly 

 understood as I could wish, your readers will pardon me, or only blame my rash- 

 ness, in attempting a task so far above my abilities. 



