— i 9 — 



Jugular Sclerites. — In the membrane connecting the pro- 

 thorax with the head there is on each side, just cephalad of 

 the dorsal corner of the episternnm, a pair of sclerites. 

 These were named by a French entomologist pieces jugu- 

 1 aires* They ma}^ be called the jugular sclerites. 



Note I. — The homology of these sclerites is not well understood. 

 They were supposed by Strans-Durckheim to represent the remains 

 of two distinct segments. But Newportf believed that they were 

 detached portions of the prothorax ; and suggested that they repre- 

 sent the paraptera of this segment. 



Note II. — -It is believed that each lateral part of each thoracic seg- 

 ment consists of three sclerites. These are named the episternum, 

 the epimeron, and the parapteron. In many cases not all of these 

 parts can be distinguished. This may be due to the non-development 

 of a part, or to the effacing of a suture between two parts. In the 

 prothorax, paraptera have never been found unless, as suggested by 

 Newport, the jugular sclerites represent these parts. In many in- 

 sects the epimera of the prothorax cannot be distinguished from the 

 episterna, the suture on each side between these sclerites being ob- 

 solete. In the insect which we are studying, either this is the case 

 or the epimera of this segment are not developed. 



Add the episternum and the jugular sclerites to the draw- 

 ing of the lateral aspect of the pronotum. 



MESOTHORAX AND METATHORAX. 



Union of these segments. — The second and third 

 thoracic segments are firmly joined together, forming a box 

 to which the two pairs of wings and the second and third 

 pairs of legs are joined. Owing to the intimate union of 

 these two segments it will be easier to describe them together 

 than separately. 



With fine pointed scissors cut away the caudal border of 

 the pronotum, that part which overlaps the mesonotum ; be 

 careful not to break the membrane connecting the prothorax 

 and mesothorax. 



*Straus-I)urckheim, Consideration G£nerales sur l'Antaoinie Coruparee des.Ani- 

 niaux Articules, p. 75. 

 f Article Insecta, Todd's Cycl. Anat. and Phys., p. 911. 



