162. Mr. W.S. MacLeay on ihe Anatomy of the 
wing where these exist. It is called the dorsolum by Kirby,* having 
been previously called dorsum by Chabrier. 
3. The scutel/wm is that part the external appearance of which is com- 
monly so called by entomologists. 
4. The postscutellum is a piece almost always completely concealed 
in the interior of the thorax, sometimes confluent with the inner face of 
this so as to be confounded with it, and sometimes being free. It is called 
Srenum by Mr. Kirby,+ but this naturalist only knew it in certain orders. 
The above four pieces when united form the tergum of the mesothorax. 
The ezght inferior or pectoral pieces of the mesothorax are the meso- 
sternum, K., medifurca, K., two episterna, 4., two epimera, A., and 
two paraptera, A.; the six latter pieces being lateral and the paraptera 
often so situated as to appear to belong to the tergum. 
1. The mesosternum is exactly to the mesothorax what the prosternum 
is to the prothorax. It is therefore called by Audouin the sternum of the 
mesothorax.§ 
2. The medifurca is well explained by Kirby.|| It is to the meso- 
thorax what the antefurca is to the prothorax. Therefore Audouin calls 
it the entothorax of the mesothoraa. 
3. The episterna are two pieces exactly analogous to those of the pro- 
thorax, and have in general similar relative positions, 
4, The epimera are exactly analogous to those of the prothorax, and 
have likewise similar relative positions. 
5. The paraptera are two lateral pieces having a relation to the 
wings. They are usually supported by the episternum, but in general 
are little developed or are even evanescent. Their situation is always near 
the wing, of which indeed they more properly form part.) 
* See Int. to Ent. Tab. 22, fig. 8. 7’. The scutum of the mesothorax in cer- 
tain Hymenopterous Insects requires further examination than I can give it in 
this paper, and I shall therefore return to the subject at some future opportu- 
nity. 
+ See Int. to Ent., Tab. 22, fig. 8. x’. 
{ See Int, to Ent., Tab. 22, fig. 8. /’. 
§ See Ann. des Sc. Nat., Tom. 1, pl. 8. 
|| See Int. to Ent., Vol. III. p. 587, Tab. 22, fig. 6. M. Cuvier calls it ‘la 
«* piéce en forme d’y grec.” 
Q In Hymenoptera the parapteron is generally above the wing; in Coleop- 
